Culture

Among low-income, uninsured, or publicly insured women ages 25-64 years who were not up to date on cervical cancer screening, 72% perceived financial barriers to screening. The most commonly reported barriers were screening appointment costs (71%) and follow-up/future treatment costs (44%), according to a study published in the peer-reviewed Journal of Women’s Health. Click here to read the article now.

Screening is effective at reducing the incidence of and mortality associated with cervical cancer. However, disparities exist in cervical cancer incidence and mortality and in cervical cancer screening based on poverty level, insurance status, race, and ethnicity. Only about 64% of uninsured women, 78% of publicly insured women, and 75% of low-income women have been screened in accordance with national screening guidelines. Perceived financial barriers to screening likely affect cervical cancer screening adherence.

“Most notably, this study illustrates the importance of the availability and awareness of health. Insurance and other financial resources to reduce perceived financial barriers to screening,” state Jennifer Smith, PhD, University of North Carolina, and coauthors of the study. “Insurance status heavily influences the actual out-of-pocket costs incurred from the cervical cancer screening appointment and labs, which may influence perceived cost burden and barriers.”

“Low-income women need greater access to insurance coverage options, Medicaid eligibility, or free screening programs so they can undergo regular cervical cancer screening without perceived financial barriers to care,” says Journal of Women’s Health Editor-in-Chief Susan G. Kornstein, MD, Executive Director of the Virginia Commonwealth University Institute for Women’s Health, Richmond, VA.

Boulder, Colo., USA: Article topics include the Great Unconformity of the
Rocky Mountain region; new Ediacara-type fossils; the southern Cascade arc
(California, USA); the European Alps and the Late Pleistocene glacial
maximum; Permian-Triassic ammonoid mass extinction; permafrost thaw; the
southern Rocky Mountains of Colorado (USA); “gargle dynamics”; invisible
gold; and alluvial fan deposits in Valles Marineris, Mars. These Geology articles are online at

https://geology.geoscienceworld.org/content/early/recent

.

A new kind of invisible gold in pyrite hosted in deformation-related
dislocations

Denis Fougerouse; Steven M. Reddy; Mark Aylmore; Lin Yang; Paul Guagliardo
...

Abstract:
Mining of “invisible gold” associated with sulfides in gold ores represents
a significant proportion of gold production worldwide. Gold hosted in
sulfide minerals has been proposed to be structurally bound in the crystal
lattice as a sulfide-gold alloy and/or to occur as discrete metallic
nanoparticles. Using a combination of microstructural quantification and
nanoscale geochemical analyses on a pyrite crystal from an orogenic gold
deposit, we show that dislocations hosted in a deformation low-angle
boundary can be enriched in Ni, Cu, As, Pb, Sb, Bi, and Au. The cumulative
trace-element enrichment in the dislocations is 3.2 at% higher compared to
the bulk crystal. We propose that trace elements were segregated during the
migration of the dislocation following the dislocation-impurity pair model.
The gold hosted in nanoscale dislocations represents a new style of
invisible gold.

View article
:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49028.1/604581/A-new-kind-of-invisible-gold-in-pyrite-hosted-in

A quantification of the effect of diagenesis on the paleoredox record
in mid-Proterozoic sedimentary rocks

Alec M. Hutchings; Alexandra V. Turchyn

Abstract:
Iron speciation in ancient sedimentary rocks is widely used to reconstruct
oceanic redox conditions over geological time, specifically to assess the
extent of oxic, euxinic (anoxic containing sulfide), and ferruginous
(anoxic containing iron) conditions. We explore how post-depositional
sedimentary processes can skew particular geochemical signals in the rock
record. One such process is when aqueous sulfide—including that produced in
the sediment column—reacts with sedimentary iron, converting non-sulfide,
highly reactive iron minerals to iron-sulfide minerals; this can lead to
increased preservation of iron as pyrite and an overestimation of seafloor
euxinia. We show that sedimentary rocks with higher (>5 wt%) total iron
content are more buffered to this effect and thus are a more reliable
indicator of true water-column euxinia. When considering this effect in the
geological past, we estimate that true euxinia in the mid-Proterozoic may
have been as much as fourfold less than previously thought—more in line
with other recent paleoredox proxies not based on iron minerals. Marine
iron and sulfate concentrations were more equivalent in
Proterozoic–Neoproterozoic oceans, suggesting this time period was
particularly susceptible to this post-depositional alteration, explaining
the extent of euxinia suggested for this geological interval.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48774.1/604580/A-quantification-of-the-effect-of-diagenesis-on

How fast do submarine fans grow? Insights from the Quaternary Golo
fans, offshore Corsica

Michael L. Sweet; Gwladys T. Gaillot; Tammy M. Rittenour; Kathrine Love;
Michael D. Blum

Abstract:
High-resolution seismic, core, and chronological data from the Quaternary
Golo deep-sea fans, offshore Corsica, France, give new insights into rates
of submarine fan growth. Average vertical deposition rates for units that
represent the Late Pleistocene glacial periods are 0.1–0.5 m/k.y.
Glacial-age deposits are sand rich; in contrast, post-glacial deposits lack
a significant sand fraction and are dominated by carbonate-rich mud. As a
result, seismically constrained volumetric rates of deposition for glacial
periods with low sea level and a subaerially exposed shelf are ~0.23 km 3/k.y., 2×–5× higher than rates during interglacials when sea
level is high, the shelf is submerged, and sand is trapped in
shallow-marine environments. At millennial time scales, variations in
deposition rate reflect climate-driven sea-level changes, autogenic
avulsion of river channels that extend across the shelf during low sea
level, and autogenic avulsion of submarine channels that shift the locus of
deposition laterally. Short-term deposition rates range from 8.6 m/k.y. at
proximal portions of submarine fans to 0.4 m/k.y. along the distal fringe.
Our data show that submarine fans can be dynamic environments with
formation and evolution of levee-confined channels and lobe complexes in 10 3–104 yr, comparable to the time scales needed to
form fluvial channel belts and delta lobes.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48911.1/604582/How-fast-do-submarine-fans-grow-Insights-from-the

Contrasting northern and southern European winter climate trends during
the Last Interglacial

J. Sakari Salonen; Maria Fernanda Sánchez-Goñi; Hans Renssen; Anna Plikk

Abstract:
The Last Interglacial (LIG; 130–115 ka) is an important test bed for
climate science as an instance of significantly warmer than preindustrial
global temperatures. However, LIG climate patterns remain poorly resolved,
especially for winter, affected by a suite of strong feedbacks such as
changes in sea-ice cover in the high latitudes. We present a synthesis of
winter temperature and precipitation proxy data from the Atlantic seaboard
of Europe, spanning from southern Iberia to the Arctic. Our data reveal
distinct, opposite latitudinal climate trends, including warming winters
seen in the European Arctic while cooling and drying occurred in southwest
Europe over the LIG. Climate model simulations for 130 and 120 ka suggest
these contrasting climate patterns were affected by a shift toward an
atmospheric circulation regime with an enhanced meridional pressure
gradient and strengthened midlatitude westerlies, leading to a strong
reduction in precipitation across southern Europe.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49007.1/604583/Contrasting-northern-and-southern-European-winter

A record of syn-tectonic sedimentation revealed by perched
alluvial fan deposits in Valles Marineris, Mars

J.M. Davis; P.M. Grindrod; S.G. Banham; N.H. Warner; S.J. Conway ...

Abstract:
On Mars, basins formed by tectonic processes are rare and mostly have
unconstrained subsidence histories. One method for understanding this
record of subsidence is through associated alluvial fans, which are sourced
from uplifted areas and accumulate in downthrown basins. The source,
morphology, and superposition of fan deposits can be used to reconstruct
fault kinematics, the relative timing of accommodation space formation,
and, in turn, the influence tectonic processes had on Martian fan
formation. Here we use high-resolution orbital data sets to characterize
sediment fan deposits associated with syn-tectonic sedimentation in two
regions of the Valles Marineris canyons: Coprates Chasma and Juventae
Chasma. These deposits comprise sediment fans on the current canyon floor
and low-gradient surfaces perched several kilometers above the canyon
floor. We interpret the low-gradient surfaces as remnant sediment fan
deposits, which originally formed at the former canyon floor and have since
been offset due to normal faulting. The preservation of vertically offset
generations of sediment fan deposits supports a progressive, basinward
migration of fault activity into the original hanging wall or repeat
activity along a fault zone. Each episode of faulting was followed by a
basinward shift in drainages, which led to fault-scarp degradation and
formation of a new generation of fans. Multiple episodes of syn-tectonic
sedimentation occurred during the evolution of the basins, with fluvial
activity sporadically active. Our results demonstrate, for the first time
on Mars, that depositional cyclicity was linked to tectonic deformation,
possibly representative of regional processes throughout Valles Marineris.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48971.1/604584/A-record-of-syn-tectonic-sedimentation-revealed-by

Seismic fault weakening via CO2 pressurization enhanced by
mechanical deformation of dolomite fault gouges

Hyun Na Kim; Byung-Dal So; Min Sik Kim; Kee Sung Han; Sol Bi Oh

Abstract:
Carbon dioxide emissions from dolomite decarbonation play an essential role
in the weakening of carbonate faults by lowering the effective normal
stress, which is thermally activated at temperatures above 600–700 °C.
However, the mechanochemical effect of low-crystalline ultrafine fault
gouge on the decarbonation and slip behavior of dolomite-bearing faults
remains unclear. In this study, we obtained a series of artificial dolomite
fault gouges with systematically varying particle sizes and dolomite
crystallinities using a high-energy ball mill. The laboratory-scale
pulverization of dolomite yielded MgO at temperatures below 50 °C,
indicating that mechanical decarbonation without significant heating
occurred due to the collapse of the crystalline structure, as revealed by
X-ray diffraction and solid-state nuclear magnetic resonance results.
Furthermore, the onset temperature of thermal decarbonation decreased to
~400 °C. Numerical modeling reproduced this two-stage decarbonation, where
the pore pressure increased due to low-temperature thermal decarbonation,
leading to slip weakening on the fault plane even at 400–500 °C; i.e.,
200–300 °C lower than previously reported temperatures. Thus, the presence
of small amounts of low-crystalline dolomite in a fault plane may lead to a
severely reduced shear strength due to thermal decomposition at ~400 °C
with a small slip weakening distance.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48938.1/604585/Seismic-fault-weakening-via-CO2-pressurization

Alpine relief limited by glacial occupation time

Bernhard Salcher; Günther Prasicek; Sebastian Baumann; Florian Kober

Abstract:
Glaciers exert a major control on the shape of mountain topography. They
tend to reduce relief above and scour troughs below the equilibrium line
altitude (ELA). While many studies report this dichotomy, relief-limiting
effects are controversial due to difficulties in quantifying key factors
such as the initial topography, the timing of glacial occupancy, or rock
uplift counteracting glacial erosion. Consequently, effectivity and degree
of glacial erosion remain ambiguous. In geologically and climatically
well-investigated parts of the European Central Alps, our calculation of
glacial occupation time (GOT) from Quaternary ELA variations allows the
quantification of gradual topographic modifications generated by the
cumulative impact of cirque erosion over the Quaternary. We show that under
low uplift, relief is effectively limited by glacial and periglacial
headwall retreat, leading to a decline in topographic relief as GOT
increases. Conversely, higher uplift rates seem to induce more persistent
valley glaciation, triggering a positive feedback loop in which steep
slopes are protected against erosion and relief increases.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48639.1/604586/Alpine-relief-limited-by-glacial-occupation-time

Spatially variable provenance of the Chinese Loess Plateau

Haobo Zhang; Junsheng Nie; Xiangjun Liu; Alex Pullen; Guoqiang Li ...

Abstract:
Loess sequences of the Chinese Loess Plateau (CLP) compose one of the most
complete Neogene–Quaternary terrestrial paleoclimatic archives.
Understanding the CLP’s sediment sources is critical to tracing Asian
aridification, atmospheric circulation patterns, and Asian monsoon
evolution. Commonly, the sediments that compose the Quaternary strata of
the CLP are considered largely homogeneous, and thus numerous studies have
applied a uniform source model when attempting to use CLP-derived proxies
as paleoclimate indicators. Here we present large-n detrital
zircon U-Pb geochronology data from the Quaternary CLP. These data support
spatial variability in sediment provenance across the CLP. At least three
distinct provenance zones are recognized for Quaternary loess strata:
central western, eastern, and northeastern. These zones received sediment
primarily from their neighboring river systems. This finding conflicts with
the classic views that attribute the Quaternary loess principally to the
deserts north and west of the CLP. We conclude that fluvial processes, and
thus precipitation, played an important and previously underemphasized role
in Quaternary dust production in northern China. Furthermore, nonuniformity
in CLP Quaternary sediment provenance raises questions about the validity
of using paleoclimate information archived in the CLP to make sweeping
regional interpretations.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48867.1/604587/Spatially-variable-provenance-of-the-Chinese-Loess

Igneous rock area and age in continental crust

Shanan E. Peters; Craig R. Walton; Jon M. Husson; Daven P. Quinn; Oliver
Shorttle ...

Abstract:
Rock quantity and age are fundamental features of Earth’s crust that
pertain to many problems in geoscience. Here we combine new estimates of
igneous rock area in continental crust from the Macrostrat database
(https://macrostrat.org/) with a compilation of detrital zircon ages in
order to investigate rock cycling and crustal growth. We find that there is
little or no decrease in igneous rock area with increasing rock age.
Instead, igneous rock area in North America exhibits four distinct
Precambrian peaks, remains low through the Neoproterozoic, and then
increases only modestly toward the recent. Peaks in Precambrian detrital
zircon age frequency distributions align broadly with peaks in igneous rock
area, regardless of grain depositional age. However, detrital zircon ages
do underrepresent a Neoarchean peak in igneous rock area; young grains and
ca. 1.1 Ga grains are also overrepresented relative to igneous area.
Together, these results suggest that detrital zircon age distributions
contain signatures of continental denudation and sedimentary cycling that
are decoupled from the cycling of igneous source rocks. Models of
continental crustal evolution that incorporate significant early increase
in volume and increased sedimentation in the Phanerozoic are well supported
by these data.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49037.1/604588/Igneous-rock-area-and-age-in-continental-crust

Explosive caldera-forming eruptions and debris-filled vents: Gargle
dynamics

Greg A. Valentine; Meredith A. Cole

Abstract:
Large explosive volcanic eruptions are commonly associated with caldera
subsidence and ignimbrites deposited by pyroclastic currents. Volumes and
thicknesses of intracaldera and outflow ignimbrites at 76 explosive
calderas around the world indicate that subsidence is commonly simultaneous
with eruption, such that large proportions of the pyroclastic currents are
trapped within the developing basins. As a result, much of an eruption must
penetrate its own deposits, a process that also occurs in large,
debris-filled vent structures even in the absence of caldera formation and
that has been termed “gargling eruption.” Numerical modeling of the
resulting dynamics shows that the interaction of preexisting deposits
(fill) with an erupting (juvenile) mixture causes a dense sheath of fill
material to be lifted along the margins of the erupting jet. This can cause
an eruption that would otherwise produce a buoyant plume and fallout
deposits to instead form pyroclastic currents as the dense sheath drives
pulsing jet behavior. Increasing thickness of fill amplifies the time
variation in jet height. Increasing the fill grain size relative to that of
the juvenile particles can result in a much higher jet due to poorer mixing
between the dense sheath and the dilute jet core. In all cases, material
collapses along the entire height of the dense sheath rather than from the
top of a simple fountain. These gargle dynamics provide strong backing for
processes that have been inferred to result in intraplinian ignimbrites and
simultaneous deposition from high- and low-energy pyroclastic currents.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48995.1/604589/Explosive-caldera-forming-eruptions-and-debris

Prior oil and gas production can limit the occurrence of
injection-induced seismicity: A case study in the Delaware Basin of
western Texas and southeastern New Mexico, USA

Noam Z. Dvory; Mark D. Zoback

Abstract:
We demonstrate that pore pressure and stress changes resulting from several
decades of oil and gas production significantly affect the likelihood of
injection-related induced seismicity. We illustrate this process in the
Delaware Basin (western Texas and southeastern New Mexico, USA), in which
hydraulic fracturing and waste-water injection have been inducing numerous
earthquakes in the southernmost part of the basin where there has been no
prior oil and gas production from the formations in which the earthquakes
are now occurring. In the seismically quiescent part of the basin, we show
that pore-pressure and poroelastic-stress changes associated with prior oil
and gas production make induced seismicity less likely. The findings of
this study have important implications for the feasibility of large-scale
carbon storage in depleted oil and gas reservoirs.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49015.1/604590/Prior-oil-and-gas-production-can-limit-the

Excess ice loads in the Indian Ocean sector of East Antarctica during
the last glacial period

Takeshige Ishiwa; Jun’ichi Okuno; Yusuke Suganuma

Abstract:
An accurate reconstruction of the Antarctic Ice Sheet is essential in order
to develop an understanding of ice-sheet responses to global climate
changes. However, the erosive nature of ice-sheet expansion and the
difficulty of accessing much of Antarctica make it challenging to obtain
field-based evidence of ice-sheet and sea-level changes before the Last
Glacial Maximum. Limited sedimentary records from Lützow-Holm and Prydz
Bays in East Antarctica demonstrate that the sea level during Marine
Isotope Stage 3 was close to the present level despite the global sea-level
drop lower than –40 m. We demonstrate glacial isostatic adjustment modeling
with refined Antarctic Ice Sheet loading histories. Our experiments reveal
that the Indian Ocean sector of the Antarctic Ice Sheet would have been
required to experience excess ice loads before the Last Glacial Maximum in
order to explain the observed sea-level highstands during Marine Isotope
Stage 3. As such, we suggest that the Antarctic Ice Sheet partly reached
its maximum thickness before the global Last Glacial Maximum.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48830.1/600851/Excess-ice-loads-in-the-Indian-Ocean-sector-of

Across-arc variations in Mo isotopes and implications for subducted
oceanic crust in the source of back-arc basin volcanic rocks

Xiaohui Li; Quanshu Yan; Zhigang Zeng; Jingjing Fan; Sanzhong Li ...

Abstract:
Molybdenum (Mo) isotope ratios provide a potential means of tracing
material recycling involved in subduction zone processes. However, the
geochemical behavior of Mo in subducted oceanic crust remains enigmatic. We
analyzed Mo isotope ratios of arc and back-arc basin lavas from the Mariana
subduction zone (western Pacific Ocean), combining newly obtained element
and Sr-Nd-Pb-Li isotope data to investigate subduction zone geochemical
processes involving Mo. The Mo isotope ratios (δ98/95Mo NIST3134; U.S. National Institute of Standards and Technology
[NIST] Mo standard) of the volcanic rocks showed clear across-arc
variations, decreasing with increasing depth to the Wadati-Benioff zone.
The high δ98/95Mo values in the Mariana Islands (–0.18‰ to
+0.38‰) correspond to high 87Sr/86Sr, low 143Nd/144Nd, and radiogenic Pb isotope ratios,
suggesting that altered upper oceanic crust played an important role in the
magma source. The low δ98/95Mo values in the Central Mariana
Trough (–0.65‰ to –0.17‰) with mantle-like Sr-Nd-Pb but slightly low δ 7Li values provide direct evidence for the contribution of deep
recycled oceanic crust to the magma source of the back-arc basin lavas. The
isotopically light Mo magmas originated by partial melting of a residual
subducted slab (eclogite) after high degrees of dehydration and then
penetrated into the back-arc mantle. This interpretation provides a new
perspective with which to investigate the deep recycling of subducted
oceanic lithosphere and associated magma petrogenesis.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48754.1/600852/Across-arc-variations-in-Mo-isotopes-and

Tectonic controls on basement exhumation in the southern Rocky
Mountains (United States): The power of combined zircon (U-Th)/He and
K-feldspar 40Ar/39Ar thermochronology

Jason W. Ricketts; Jacoup Roiz; Karl E. Karlstrom; Matthew T. Heizler;
William R. Guenthner ...

Abstract:
The Great Unconformity of the Rocky Mountain region (western North
America), where Precambrian crystalline basement is nonconformably overlain
by Phanerozoic strata, represents the removal of as much as 1.5 b.y. of
rock record during 10-km-scale basement exhumation. We evaluate the timing
of exhumation of basement rocks at five locations by combining geologic
data with multiple thermochronometers. 40Ar/39Ar
K-feldspar multi-diffusion domain (MDD) modeling indicates regional
multi-stage basement cooling from 275 to 150 °C occurred at 1250–1100 Ma
and/or 1000–700 Ma. Zircon (U-Th)/He (ZHe) dates from the Rocky Mountains
range from 20 to 864 Ma, and independent forward modeling of ZHe data is
also most consistent with multi-stage cooling. ZHe inverse models at five
locations, combined with K-feldspar MDD and sample-specific geochronologic
and/or thermochronologic constraints, document multiple pulses of basement
cooling from 250 °C to surface temperatures with a major regional basement
exhumation event 1300–900 Ma, limited cooling in some samples during the
770–570 Ma breakup of Rodinia and/or the 717–635 Ma snowball Earth, and ca.
300 Ma Ancestral Rocky Mountains cooling. These data argue for a tectonic
control on basement exhumation leading up to formation of the
Precambrian-Cambrian Great Unconformity and document the formation of
composite erosional surfaces developed by faulting and differential uplift.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49141.1/600853/Tectonic-controls-on-basement-exhumation-in-the

Reorienting the West African craton in Paleoproterozoic–Mesoproterozoic
supercontinent Nuna

Zheng Gong; David A.D. Evans; Nasrrddine Youbi; Abdelhak Ait Lahna; Ulf
Söderlund ...

Abstract:
The location of the West African craton (WAC) has been poorly constrained
in the Paleoproterozoic–Mesoproterozoic supercontinent Nuna (also known as
Columbia). Previous Nuna reconstruction models suggested that the WAC was
connected to Amazonia in a way similar to their relative position in
Gondwana. By an integrated paleomagnetic and geochronological study of the
Proterozoic mafic dikes in the Anti-Atlas Belt, Morocco, we provide two
reliable paleomagnetic poles to test this connection. Incorporating our new
poles with quality-filtered poles from the neighboring cratons of the WAC,
we propose an inverted WAC-Amazonia connection, with the northern WAC
attached to northeastern Amazonia, as well as a refined configuration of
Nuna. Global large igneous province records also conform to our new
reconstruction. The inverted WAC-Amazonia connection suggests a substantial
change in their relative orientation from Nuna to Gondwana, providing an
additional example of large-magnitude cumulative azimuthal rotations
between adjacent continental blocks over supercontinental cycles.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48855.1/600854/Reorienting-the-West-African-craton-in

New Ediacara-type fossils and late Ediacaran stratigraphy from the
northern Qaidam Basin (China): Paleogeographic implications

Ke Pang; Chengxi Wu; Yunpeng Sun; Qing Ouyang; Xunlai Yuan ...

Abstract:
Ediacara-type macrofossils characterize the late Ediacaran Period and are
pivotal in understanding the early evolution of animals on the eve of the
Cambrian explosion and useful in late Ediacaran biostratigraphy. They have
been discovered on almost all major paleocontinents, except the North China
and Tarim blocks, as well as on a series of northwestwest–oriented cratonic
fragments between the two blocks, including the Olongbuluke terrane of the
Qaidam block, where the terminal Ediacaran successions developed. We report
a newly discovered terminal Ediacaran biotic assemblage, the Quanjishan
assemblage, containing Ediacara-type fossils from the Zhoujieshan Formation
of the Quanji Group in the Olongbuluke terrane, Qaidam Basin, northwestern
China. The Quanjishan assemblage is dominated by the non-biomineralized
tubular taxon Shaanxilithes, which has the potential to be a
terminal Ediacaran index fossil, and by the iconic frondose rangeomorph Charnia, which represents the only unambiguous Ediacara-type
fossil discovered in northwestern China. The co-occurrence of Charnia and Shaanxilithes from the Quanjishan assemblage
likely constrains the depositional age of the Zhoujieshan Formation to be
terminal Ediacaran (ca. 550–539 Ma) and the immediately underlying
Hongtiegou diamictites to be late Ediacaran, probably representing
post-Gaskiers glacial deposition. The occurrence of post-Gaskiers Ediacaran
glaciation and similarities between the late Ediacaran–early Paleozoic
lithostratigraphic and biostratigraphic sequences in the Olongbuluke
terrane of the Qaidam block and the North China block suggest that these
two blocks may have been located close to each other during this time
period, and situated in the middle to high latitudes instead of the
equatorial region.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48842.1/600855/New-Ediacara-type-fossils-and-late-Ediacaran

Slab-derived sulfate generates oxidized basaltic magmas in the southern
Cascade arc (California, USA)

Michelle J. Muth; Paul J. Wallace

Abstract:
Whether and how subduction increases the oxidation state of Earth’s mantle
are two of the most important unresolved questions in solid Earth
geochemistry. Using data from the southern Cascade arc (California, USA),
we show quantitatively for the first time that increases in arc magma
oxidation state are fundamentally linked to mass transfer of isotopically
heavy sulfate from the subducted plate into the mantle wedge. We
investigate multiple hypotheses related to plate dehydration and melting
and the rise and reaction of slab melts with mantle peridotite in the
wedge, focusing on electron balance between redox-sensitive iron and sulfur
during these processes. These results show that unless slab-derived silicic
melts contain much higher dissolved sulfur than is indicated by currently
available experimental data, arc magma generation by mantle wedge melting
must involve multiple stages of mantle metasomatism by slab-derived
oxidized and sulfur-bearing hydrous components.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48759.1/600856/Slab-derived-sulfate-generates-oxidized-basaltic

Long-term Aptian marine osmium isotopic record of Ontong Java Nui
activity

Hironao Matsumoto; Rodolfo Coccioni; Fabrizio Frontalini; Kotaro Shirai;
Luigi Jovane ...

Abstract:
The early to mid-Aptian was punctuated by episodic phases of organic-carbon
burial in various oceanographic settings, which are possibly related to
massive volcanism associated with the emplacement of the Ontong Java,
Manihiki, and Hikurangi oceanic plateaus in the southwestern Pacific Ocean,
inferred to have formed a single plateau called Ontong Java Nui.
Sedimentary osmium (Os) isotopic compositions are one of the best proxies
for determining the timing of voluminous submarine volcanic episodes.
However, available Os isotopic records during the age are limited to a
narrow interval in the earliest Aptian, which is insufficient for the
reconstruction of long-term hydrothermal activity. We document the early to
mid-Aptian Os isotopic record using pelagic Tethyan sediments deposited in
the Poggio le Guaine (Umbria-Marche Basin, Italy) to precisely constrain
the timing of massive volcanic episodes and to assess their impact on the
marine environment. Our new Os isotopic data reveal three shifts to
unradiogenic values, two of which correspond to black shale horizons in the
lower to mid-Aptian, namely the Wezel (herein named) and Fallot Levels.
These Os isotopic excursions are ascribed to massive inputs of unradiogenic
Os to the ocean through hydrothermal activity. Combining the new Os
isotopic record with published data from the lowermost Aptian organic-rich
interval in the Gorgo a Cerbara section of the Umbria-Marche Basin, it can
be inferred that Ontong Java Nui volcanic eruptions persisted for ~5 m.y.
during the early to mid-Aptian.
View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48863.1/600857/Long-term-Aptian-marine-osmium-isotopic-record-of

Anisotropy-revealed change in hydration along the Alaska subduction
zone

Colton Lynner

Abstract:
Megathrust earthquake behavior in subduction zones is controlled by a
variety of factors including the hydration state of the subducting slab.
Increased hydration reduces the occurrence of great, damaging earthquakes
by diminishing the strength of the material along the interface between
tectonic plates. Understanding variations in hydration in subductions zones
is necessary for properly assessing the overall hazard posed by each
region. Fortunately, seismic anisotropy is strongly dependent upon
hydration of the subducting crust and lithosphere. I present shear-wave
splitting measurements that illuminate changes in anisotropy, and therefore
hydration, of the subducting Pacific plate beneath the Alaska subduction
zone (northern Pacific Ocean). Variations in shear-wave splitting directly
correlate to changes in the behavior of great, megathrust earthquakes. My
measurements show that the Shumagin seismic gap is characterized by a
hydrated subducting slab, explaining the long-term lack of great
earthquakes. Observations in the immediately adjacent Semidi segment, which
experiences great events regularly, indicate a far less hydrated slab.
These results are driven by the preferential alignment of paleo-spreading
fabrics of the Pacific plate. Where fabrics are more closely aligned with
the orientation of the trench, outer-rise faulting and plate hydration is
enhanced. These results highlight the importance of changes in preexisting
slab structures and subsequent hydration in the production of great,
damaging earthquakes.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48860.1/600696/Anisotropy-revealed-change-in-hydration-along-the

Out-of-phase Late Pleistocene glacial maxima in the Western Alps
reflect past changes in North Atlantic atmospheric circulation

Natacha Gribenski; Pierre G. Valla; Frank Preusser; Thibault Roattino;
Christian Crouzet ...

Abstract:
Paleoglacier reconstructions in the northern and southern forelands of the
European Alps indicate a synchronous Late Pleistocene glacial maximum
during Marine Isotope Stage (MIS) 2, in phase with global ice volume
records. However, strong controversy remains for the western foreland,
where scarce and indirect dating as well as modeling studies suggest
glacial maxima out of phase with the rest of the Alps. New luminescence
dating brings the first direct Late Pleistocene glacial chronology for the
western Alpine foreland and reveals two major glacier advances of similar
maximum extent, at ca. 75–60 and ca. 40–30 ka, coinciding with MIS 4 and
late MIS 3. We propose that asynchrony in glacial maxima between the
western and the northern and southern Alpine forelands results from a
progressive spatial reorganization of the atmospheric circulation over the
North Atlantic in response to Northern Hemisphere ice-sheet fluctuations.
While such a feedback mechanism has emerged from general circulation
models, our Late Pleistocene paleoglacial reconstruction permits tracking
of the spatiotemporal evolution of moisture advection patterns over Western
Europe.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48688.1/600697/Out-of-phase-Late-Pleistocene-glacial-maxima-in

Highly localized upper mantle deformation during plate boundary
initiation near the Alpine fault, New Zealand

Steven Kidder; David J. Prior; James M. Scott; Hamid Soleymani; Yilun Shao

Abstract:
Peridotite xenoliths entrained in magmas near the Alpine fault (New
Zealand) provide the first direct evidence of deformation associated with
the propagation of the Australian-Pacific plate boundary through the region
at ca. 25–20 Ma. Two of 11 sampled xenolith localities contain fine-grained
(40–150 mm) rocks, indicating that deformation in the upper mantle was
focused in highly sheared zones. To constrain the nature and conditions of
deformation, we combine a flow law with a model linking recrystallized
fraction to strain. Temperatures calculated from this new approach (625–970
°C) indicate that the observed deformation occurred at depths of 25–50 km.
Calculated shear strains were between 1 and 100, which, given known plate
offset rates (10–20 mm/yr) and an estimated interval during which
deformation likely occurred (<1.8 m.y.), translate to a total shear zone
width in the range 0.2–32 km. This narrow width and the position of
mylonite-bearing localities amid mylonite-free sites suggest that early
plate boundary deformation was distributed across at least ~60 km but
localized in multiple fault strands. Such upper mantle deformation is best
described by relatively rigid, plate-like domains separated by rapidly
formed, narrow mylonite zones.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48532.1/600699/Highly-localized-upper-mantle-deformation-during

Morphological selectivity of the Permian-Triassic ammonoid mass
extinction

Xu Dai; Dieter Korn; Haijun Song

Abstract:
Ammonoids suffered a diversity bottleneck during the Permian-Triassic mass
extinction (PTME) and experienced a rapid diversification in the Early
Triassic. However, the kinds of ammonoids that were more likely to survive
the PTME and that fueled subsequent diversification are still poorly known.
We compiled a comprehensive morphological data set and used the nonmetric
multidimensional scaling method to reveal the impact of the PTME on the
morphological selectivity of ammonoids. Our results show that
postextinction taxa occupied a quite different morphospace when compared
with the pre-extinction assemblages. The survivors were mainly smooth and
weakly ornamented forms, while the late Permian species were dominated by
coarsely ornamented forms. Contrary to previously recognized nonselective
patterns, these results suggest a morphological selectivity of the
Permian-Triassic crisis. Newcomers in the Griesbachian were mainly
compressed and smooth forms. This morphological shift from the coarsely
ornamented ammonoids dominating the Changhsingian to the smooth ammonoids
dominating the Griesbachian possibly suggests an ecological turnover of
ammonoids during the PTME.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48788.1/600700/Morphological-selectivity-of-the-Permian-Triassic

Permafrost thaw induced abrupt changes in hydrology and carbon cycling
in Lake Wudalianchi, northeastern China

Yuan Yao; Yongsong Huang; Jiaju Zhao; Li Wang; Youhua Ran ...

Abstract:
Lakes in the permafrost zone have been proposed to serve as key outlets for
methane and carbon dioxide emissions. However, there has been no geological
record of the hydrological and biogeochemical responses of lakes throughout
the thawing of surrounding permafrost. We use multiple biomarker and
isotopic proxies to reconstruct hydrological and biogeochemical changes in
Lake Wudalianchi in northeastern China during regional thawing of the
permafrost. We show permafrost thawing, as indicated by lignin degradation,
initiated rapid lake water freshening as a result of the opening of
groundwater conduits, and negative organic δ13C excursion due to
increased inorganic and organic carbon fluxes. These hydrological changes
were followed, with an ~5–7 yr delay, by abrupt and persistent increases in
microbial lake methanotrophy and methanogenesis, indicating enhanced
anaerobic organic decomposition and methane emissions from lakes as
permafrost thaws. Our data provide a detailed assessment of the processes
involved during permafrost thaw, and highlight the importance of lakes in
ventilating greenhouse gases to the atmosphere.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48891.1/600701/Permafrost-thaw-induced-abrupt-changes-in

Erosion of the Himalaya-Karakoram recorded by Indus Fan deposits since
the Oligocene

Han Feng; Huayu Lu; Barbara Carrapa; Hanzhi Zhang; Jun Chen ...

Abstract:
The Cenozoic erosion history of the Himalaya-Karakoram, which is a function
of tectonically driven uplift and monsoon climatic evolution in South Asia,
remains elusive, especially prior to the Miocene. Here, we present a
multiproxy geochemical and thermochronological analysis of the oldest
samples available from the Arabian Sea, which we used to investigate the
erosion history of the Himalayan and Karakoram orogenic system. The Indus
Fan records rapid and sustained erosion of the Himalayan-Karakoram
mountains from before 24 Ma (ca. 30) to ca. 16 Ma concurrent with changing
provenance from the Indian (Himalayan) and Eurasian plates. Our data,
combined with previous studies of younger Indus Fan deposits, indicate that
the mid-to-late Cenozoic erosion history of the Himalayan-Karakoram
mountains is overall consistent with a vigorous monsoonal climate from the
late Oligocene to middle Miocene and with changes in global climate in the
late Miocene, whereas erosion and deposition are relatively insensitive to
changes in sources and rock erodibility. Although tectonic processes were
active throughout, we suggest that the erosional signatures of the
Himalayan-Karakoram mountains from the Indus Fan largely preserve a record
of climate changes since the Oligocene.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48445.1/600703/Erosion-of-the-Himalaya-Karakoram-recorded-by

Raising the West: Mid-Cenozoic Colorado-plano related to subvolcanic
batholith assembly in the Southern Rocky Mountains (USA)?

Peter W. Lipman

Abstract:
The Southern Rocky Mountains of Colorado, United States, have the highest
regional elevation in North America, but present-day crustal thickness
(~42–47 km) is no greater than for the adjacent, topographically lower High
Plains and Colorado Plateau. The chemistry of continental-arc rocks of the
mid-Cenozoic Southern Rocky Mountain volcanic field, calibrated to
compositions and Moho depths at young arcs, suggests that paleocrustal
thickness may have been 20%–35% greater than at present and elevations
accordingly higher. Thick mid-Cenozoic Rocky Mountain crust and high
paleo-elevations, comparable to those inferred for the Nevadaplano farther
west in the United States from analogous volcanic chemistry, could be
consistent with otherwise-perplexing evidence for widespread rapid erosion
during volcanism. Variable mid-Cenozoic crustal thickening and uplift could
have resulted from composite batholith growth during volcanism,
superimposed on prior crustal thickening during early Cenozoic (Laramide)
compression. Alternatively, the arc–crustal thickness calibration may be
inappropriate for high-potassium continental arcs, in which case other
published interpretations using similar methods may also be unreliable.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48963.1/600704/Raising-the-West-Mid-Cenozoic-Colorado-plano

Labyrinth patterns in Magadi (Kenya) cherts: Evidence for early
formation from siliceous gels

Kennie Leet; Tim K. Lowenstein; Robin W. Renaut; R. Bernhart Owen; Andrew
Cohen

Abstract:
Sedimentary cherts, with well-preserved microfossils, are known from the
Archean to the present, yet their origins remain poorly understood. Lake
Magadi, Kenya, has been used as a modern analog system for understanding
the origins of nonbiogenic chert. We present evidence for synsedimentary
formation of Magadi cherts directly from siliceous gels. Petrographic
thin-section analysis and field-emission scanning electron microscopy of
cherts from cores drilled in Lake Magadi during the Hominin Sites and
Paleolakes Drilling Project in 2014 led to the discovery of two-dimensional
branching "labyrinth patterns" in chert, which are a type of fractal
"squeeze" pattern formed at air-liquid interfaces. Labyrinth patterns
preserved in chert from Lake Magadi cores indicate invasion of air along
planes in dewatering gels. These patterns support the precipitation of
silica gels in the saline-alkaline Lake Magadi system and syndepositional
drying of gels in contact with air as part of chert formation. Recognizing
cherts as syndepositional has been critical for our use of them for U-Th
dating. Identification of labyrinth patterns in ancient cherts can provide
a better understanding of paleoenvironmental and geochemical conditions in
the past.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G48771.1/600705/Labyrinth-patterns-in-Magadi-Kenya-cherts-Evidence

Serpentinized peridotite versus thick mafic crust at the Romanche
oceanic transform fault

Emma P.M. Gregory; Satish C. Singh; Milena Marjanović; Zhikai Wang

Abstract:
The crust beneath transform faults at slow-spreading ridges has been
considered to be thin, comprising a thin mafic layer overlying
serpentinized peridotite. Using wide-angle seismic data, we report the
presence of a Moho at ~6 km depth and a low-velocity anomaly extending down
to 9 km beneath the 20-km-wide Romanche transform valley floor in the
equatorial Atlantic Ocean. The low crustal velocities above the Moho could
be due to either highly serpentinized mantle peridotite or fractured mafic
rocks. The existence of clear Moho reflections and the occurrence of a
large crustal-depth rupture during the 2016 magnitude 7.1 earthquake
suggest that the crust likely consists of fractured mafic material.
Furthermore, the presence of low velocities below the Moho advocates for
extensive serpentinization of the mantle, indicating that the Moho
reflection is unlikely to be produced by a serpentinization front. The
crust to the north of the transform fault likely consists of mafic
material, but that in the south appears to be more amagmatic, possibly
containing serpentinized peridotite. Our results imply that the transform
fault structure is complex and highly heterogeneous, and thus would have
significant influence on earthquake rupture and alteration processes.

View article:

https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G49097.1/600706/Serpentinized-peridotite-versus-thick-mafic-crust

Keep your checklists handy because the 62nd Supplement to the American Ornithological Society’s Check-list of North American Birds, publishing today in Ornithology, includes numerous updates to the classification of the continent’s bird species. A few highlights from this year’s supplement, detailed below, include species splits for Mew Gull, Barred Owl, and Sedge Wren, among quite a few others; a transfer back to an old genus for Ruby-crowned Kinglet; and a revision of the linear sequence of passerine families. The Check-list, published since 1886, is updated annually by the AOS’s North American Classification Committee (NACC), the official authority on the names and classification of the region’s birds, and is consulted by birders and professional ornithologists alike. 

The full Check-list supplement is available at: https://academic.oup.com/auk/advance-article/doi/10.1093/ornithology/ukab037/6309332.

Species Splits

Splitting of Barred Owl and Cinereous Owl (Proposal 2021-C-8)

Based primarily on differences in vocalizations, the Barred Owl (Strix varia) is being split into two species, the Barred Owl, which retains its English and scientific names for U.S. and Canadian populations, and the Cinereous Owl (Strix sartorii) for its counterpart in Mexico. “Vocalizations are particularly important for species recognition in owls,” NACC chair Terry Chesser of the U.S. Geological Survey explains. The proposal to split Barred Owl into two species, submitted by Nathan Pieplow (University of Colorado Boulder) and Andrew Spencer (Cornell Laboratory of Ornithology), focused on key differences in both their rhythm and series songs, specifically in the series song, which they summarize as: “[sartorii’s] syncopated beginning, its uniformity in pitch, and its lack of a drawn-out ‘hoo-wah’ note at the end. In the Barred Owl’s series song, the highest and loudest notes are at the end, while in that of sartorii, the highest and loudest notes are in the middle.” 

Pieplow and colleagues were surprised and dismayed, when returning to many previously known locations to record vocalizations of Cinereous Owl, that there appears to have been a severe decline and reduction in range for this species. Moreover, while searching at sites in Oaxaca, Mexico, where this species had previously been found, they instead observed the Fulvous Owl (Strix fulvescens), a close relative more typically found farther south in Mexico and Central America, but which appears to have extended its range northward.

Splitting of Mew Gull into Common Gull and Short-billed Gull (Proposal 2021-A-3)

“If you’re a coast-to-coast birder, you may be able to pick up a new species this winter,” Chesser quips, describing the split of Mew Gull (Larus canus) into two species: Common Gull (Larus canus) and Short-billed Gull (Larus brachyrhynchus), the name used for this species as long ago as the first edition of the Check-list in 1886. The Common Gull breeds in Eurasia and is a casual visitor to the eastern U.S. and Canada, and occasionally ventures to Alaska, whereas the Short-billed Gull breeds in northwestern North America and winters south along the Pacific coast and also into the interior, primarily of the western U.S. This split is based mainly on differences in display vocalizations but also on genetic and other morphological differences outlined in a proposal by NACC member Pamela C. Rasmussen (Michigan State University). These species had been lumped based on what is now viewed as weak evidence from a paper published in 1919. 

Splitting of Sedge Wren and Grass Wren (Proposal 2021-C-3)

Previous ideas about how Sedge Wren (Cistothorus platensis) should be divided turn out to be misguided, according to Chesser, who authored a proposal, based in part on a prior proposal to South American Classification Committee (SACC), to split this species. In the 1998 Check-list, Sedge Wren was considered a single species distributed from Canada to extreme southern South America, comprising three distinct groups: stellaris, whose range extended from Canada to Panama, and two other groups distributed in South America, platensis and polyglottus. However, the species split, which is based on vocalizations and genetics, does not occur where we might have expected it would, based on what we thought we knew about intraspecific variation in the species. Instead, it turns out that the populations breeding in Canada and the U.S. are distinct from all other populations, including those breeding in Mexico, Central America, and South America, and are being split from the rest. The new southern species, Grass Wren (Cistothorus platensis), will retain the scientific name due to reasons of priority, but the new northern species will keep the English name Sedge Wren (Cistothorus stellaris). The SACC had previously made this split after consideration of the separate proposal to that committee.

Transfers Between Genera

A New (Old) Genus for the Ruby-crowned Kinglet (Proposal 2021-A-9)

The Ruby-crowned Kinglet (Regulus calendula, now Corthylio calendula), a tiny olive-colored songbird with a bright red but hard-to-see crown in males, breeds in forests across the U.S. and Canada and winters as far south as Central America. It’s one of six species in the family Regulidae, all currently placed in the same genus, Regulus. Two species are found in the New World, Golden-crowned Kinglet (Regulus satrapa) and Ruby-crowned Kinglet; and four species in the Old World, including the Firecrest (Regulus ignicapilla) and Goldcrest (Regulus regulus). In the 1931 AOU Check-list, the Ruby-crowned Kinglet had been transferred to its own genus, Corthylio, based on morphological differences from the other species, but as of the 1957 Check-list it was returned to Regulus, with Corthylio relegated to subgenus status, and it has been placed in Regulus ever since. 

“It has long been known that the Ruby-crowned Kinglet is markedly divergent from the other regulids in plumage and other aspects of external anatomy, reflected by the fact that the genus Corthylio Cabanis, 1853, was erected for this species,” authors Brandon Woo and Natalia C. García (Cornell University) and NACC member Pamela C. Rasmussen (Michigan State University) state in their proposal. Moreover, vocal and genetic data, including molecular studies dating from the early days of molecular systematics to the current genomics era, have consistently shown that the Ruby-crowned Kinglet is strikingly different from other species placed in Regulus. 

“This is my favorite proposal of the year,” Chesser notes, “and I think it will be interesting to birders for the same reasons. I hope this generates new appreciation for an unassuming little bird that is of great interest evolutionarily and really distinctive from other species in its family.”

Linear Sequence Revision

Revision of Linear Sequence of Passerine Families (Proposal 2021-B-7)

A proposal by Chesser and NACC member Shawn Billerman based on new, concordant information from three recent genomic studies of passerines has led to a reshuffling and update to the linear sequence of passerine families to better reflect their phylogenetic relationships. “This is a big step forward that reflects a wealth of new information on evolutionary relationships among passerine families,” Chesser explains. “This revision will create short-term disturbance, but we think this will be more than offset by the benefits of having a more scientifically accurate classification, which should be stable into the future, with occasional minor changes. The fact that several genomic studies produced virtually the same phylogeny was the key factor in convincing us that the time was right for this revision.”

About the Journal

Ornithology (formerly, The Auk: Ornithological Advances) is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The journal’s name changed to Ornithology in January of 2021. Ornithology commenced publication in 1884 and in 2009 was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.

This year marks the 100th anniversary of the discovery of insulin, a scientific breakthrough that transformed Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, from a terminal disease into a manageable condition.

Today, Type 2 diabetes is 24 times more prevalent than Type 1. The rise in rates of obesity and incidence of Type 2 diabetes are related and require new approaches, according to University of Arizona researchers, who believe the liver may hold the key to innovative new treatments.

"All current therapeutics for Type 2 diabetes primarily aim to decrease blood glucose. So, they are treating a symptom, much like treating the flu by decreasing the fever," said Benjamin Renquist, an associate professor in the UArizona College of Agriculture and Life Sciences and BIO5 Institute member. "We need another breakthrough."

In two newly published papers in Cell Reports, Renquist, along with researchers from Washington University in St. Louis, the University of Pennsylvania and Northwestern University, outline a new target for Type 2 diabetes treatment.

Renquist, whose research lab aims to address obesity-related diseases, has spent the last nine years working to better understand the correlation between obesity, fatty liver disease and diabetes, particularly how the liver affects insulin sensitivity.

"Obesity is known to be a cause of Type 2 diabetes and, for a long time, we have known that the amount of fat in the liver increases with obesity," Renquist said. "As fat increases in the liver, the incidence of diabetes increases."

This suggested that fat in the liver might be causing Type 2 Diabetes, but how fat in the liver could cause the body to become resistant to insulin or cause the pancreas to over-secrete insulin remained a mystery, Renquist said.

Renquist and his collaborators focused on fatty liver, measuring neurotransmitters released from the liver in animal models of obesity, to better understand how the liver communicates with the brain to influence metabolic changes seen in obesity and diabetes.

"We found that fat in the liver increased the release of the inhibitory neurotransmitter Gamma-aminobutyric acid, or GABA," Renquist said. "We then identified the pathway by which GABA synthesis was occurring and the key enzyme that is responsible for liver GABA production - GABA transaminase."

A naturally occurring amino acid, GABA is the primary inhibitory neurotransmitter in the central nervous system, meaning it decreases nerve activity.

Nerves provide a conduit by which the brain and the rest of the body communicate. That communication is not only from the brain to other tissues, but also from tissues back to the brain, Renquist explained.

"When the liver produces GABA, it decreases activity of those nerves that run from the liver to the brain. Thus, fatty liver, by producing GABA, is decreasing firing activity to the brain," Renquist said. "That decrease in firing is sensed by the central nervous system, which changes outgoing signals that affect glucose homeostasis."

To determine if increased liver GABA synthesis was causing insulin resistance, graduate students in Renquist's lab, Caroline Geisler and Susma Ghimire, pharmacologically inhibited liver GABA transaminase in animal models of Type 2 diabetes.

"Inhibition of excess liver GABA production restored insulin sensitivity within days," said Geisler, now a postdoctoral researcher at the University of Pennsylvania and lead author on the papers. "Longer term inhibition of GABA-transaminase resulted in decreased food intake and weight loss."

Researchers wanted to ensure the findings would translate to humans. Kendra Miller, a research technician in Renquist's lab, identified variations in the genome near GABA transaminase that were associated with Type 2 diabetes. Collaborating with investigators at Washington University, the researchers showed that in people with insulin resistance, the liver more highly expressed genes involved in GABA production and release.

The findings are the foundation of an Arizona Biomedical Research Commission-funded clinical trial currently underway at Washington University School of Medicine in St. Louis with collaborator Samuel Klein, co-author on the study and a Washington University professor of medicine and nutritional science. The trial will investigate the use of a commercially available Food and Drug Administration-approved inhibitor of GABA transaminase to improve insulin sensitivity in people who are obese.

"A novel pharmacological target is just the first step in application; we are years away from anything reaching the neighborhood pharmacy," Renquist said. "The magnitude of the obesity crisis makes these promising findings an important first step that we hope will eventually impact the health of our family, friends and community."

Arlington, Va., June 29, 2021 - In the midst of the COVID-19 pandemic, infection preventionists at two Southern California hospitals took extreme measures to stop the spread of a deadly fungus that has emerged in the U.S. and around the world. The two will detail their proactive responses in oral presentations today at the Association for Professionals in Infection Control and Epidemiology's (APIC's), 48th Annual Conference.

In separate responses, Scripps Memorial in La Jolla and UCLA Health in Los Angeles isolated suspected or confirmed patients, worked closely with public health departments and information technology and lab teams at their facilities, and implemented aggressive measures to prevent the pathogen, Candida auris, from spreading.

"The fact that these two teams recognized this threat and were able to mobilize so quickly and effectively while also on high alert for COVID is remarkable," said APIC 2021 President Ann Marie Pettis, BSN, RN, CIC, FAPIC. "Their case studies demonstrate how important it is that hospitals, clinics, and long-term care facilities have enough infection preventionists and resources to train staff and monitor safety protocols so they can prevent harm on multiple fronts."

C. auris is a type of fungus that causes severe, often fatal infections and is resistant to most antifungal drugs. It can be carried on a patient's skin and can survive on surfaces for more than a month, allowing it to spread easily among patients. Most hospital disinfectants can't kill C. auris, making it difficult to eradicate from the healthcare environment. It is also easy to misidentify in lab tests.

In March 2020, during the initial influx of COVID-19 patients, infection preventionist Elizabeth A. Jefferson, BS, PhD, CIC, of Scripps Memorial, was notified that her facility had received the first known case of C. auris in San Diego County.

Initially flagged and isolated because the patient had received healthcare abroad, laboratory tests confirmed C. auris in a wound. The patient remained hospitalized in isolation for 47 days, during which time the team implemented aggressive cleaning measures, including use of a disinfectant that was effective against C. auris and UV light for terminal cleaning of all patient rooms.

"Education of staff was essential," said Jefferson. "Staff had to clean and disinfect the room twice a day, and then clean any shared equipment, because if Candida auris sets up shop in your facility, it is extremely difficult to get rid of."

The team partnered with public health, including the CDC's Antibiotic Resistance Lab Network, on routine surveillance testing to ensure there was no transmission.

"Hospitals need to be on the lookout for C. auris," said Jefferson. "You don't know if a patient is colonized or infected unless you have specialized laboratory equipment."

As a result, there was no transmission of the fungal pathogen that has infected nearly 1,800 patients in 15 states and the District of Columbia since it was first detected in the U.S. in 2015.

When C. auris started to surge in Southern California during the summer of 2020, UCLA Health was ready. Knowing the devastation C. auris had caused in other states, they had already created a multi-level notification system designed to catch potential cases early and prevent transmission.

Collaborating with their electronic medical records (EMR) team and the lab, the infection preventionists made sure the EMR system was set up to screen every patient for both COVID and Candida auris when they entered the facility. High-risk patients were flagged and tested appropriately with subsequent notifications sent to infection prevention, environmental services, the lab, and nursing. The system placed holds in patient charts prior to discharge or transfer to enable communication with the health department and receiving facilities about the patient's C. auris status.

The system triggered reminders for stringent cleaning protocols which included testing of environmental surfaces after terminal cleaning to ensure that the patient's room was clear of the organism.

"Having an in-house lab that could test for C. auris and collaborating with the EMR team to build a set of screening steps into our EMR created a failsafe way to ensure we could monitor and track any suspected C. auris cases at our facility. This process was effective in prevention of cross contamination in the healthcare environment" said Urvashi Parti, MPH, infection preventionist at UCLA Health.

Another factor for success was engaging senior leadership so they understood the importance of monitoring both C. auris and COVID at the same time.

"We had the full support of senior leaders who made sure we had the resources to support early identification of C. auris during the COVID-19 pandemic," said Shaunte Walton, MS, CIC, Health System Director of Clinical Epidemiology & Infection Prevention at UCLA Health.

Black men most likely to benefit from advanced prostate cancer therapies are 11 percent less likely to get them than non-Black men. This happens despite apparent equal opportunities in obtaining health care services, a new study in American veterans shows.

Publishing in the journal Cancer online June 29, the study showed that Black male veterans were slightly (5 percent) more likely to receive radiation or surgery for prostate cancer than non-Black men and that veterans of all races likely to benefit from such definitive therapy were also 40 percent more likely to get it compared to those who did not need it.

Led by researchers from NYU Langone Health and Perlmutter Cancer Center, the new analysis showed that, despite these broad advantages in obtaining advanced care, the Black men most likely to benefit from these treatments (i.e., those men with aggressive prostate cancer who were otherwise healthy) were 11 percent less likely to get them than non-Black men of similar age and cancer severity. And other research has documented that Black men are still three times more likely to die from the disease than non-Black patients.

"Our study suggests, for reasons that remain unclear, that Black men who need treatment may be choosing against the most beneficial prostate cancer therapies (which are often more invasive), or that such 'high- benefit' treatments, are not being offered to them as aggressively as they are to non-Black patients," says study co-investigator Joseph Ravenell, MD, associate dean for diversity affairs and inclusion at NYU Langone.

Ravenell, an associate professor at NYU Grossman School of Medicine and co-leader of community outreach and engagement at Perlmutter Cancer Center, says one possible reason for this treatment disparity is that, as past studies have found, some Black men may have greater fears than non-Black patients about side effects of aggressive therapy, such as the risk of incontinence and erectile dysfunction. These fears, he says, and other underlying reasons related to their expectations of treatment should be discussed directly with Black patients when treatment options are being considered.

"Our findings strongly indicate that patients and physicians should discuss fears, values, and preferences when considering all of the relevant treatment options for prostate cancer," says study senior investigator and urologic surgeon Danil Makarov, MD, MHS.

"Despite great strides in prostate cancer care over the past few decades, racial disparities in care persist, and there remains a lot to be done to better understand why this is happening and what we can do to finally close the gap," says Makarov, an associate professor in the Departments of Urology and Population Health at NYU Grossman School of Medicine.

"At the end of day, our goal is to offer patients the most appropriate cancer care they need, using a culturally sensitive approach," says Makarov, also a member of the Perlmutter Cancer Center, whose team is examining interventions such as counseling Black men on their risks and the benefits of prostate cancer screening, which could reduce disparities in care.

The findings come from an analysis of the medical records of 35,427 men treated for early to moderate prostate cancer at U.S. Veterans' Health Administration facilities from 2011 to 2017. Most were over age 60, were married, and had no other serious health issue.

The study also confirmed earlier work that Black men are likely to be diagnosed with prostate cancer two years earlier than men of other races across all age groups. Black men are also more likely to be diagnosed with more aggressive forms of the disease than their non-Black counterparts. Makarov says more research is needed to determine if any underlying structural or cultural bias is behind this disparity.

For the study, researchers analyzed data from the Veterans Health Administration's (VHA) Corporate Data Warehouse and Medicare. From these national databases, they identified all men diagnosed with prostate cancer and characterized them by their life expectancy (based on their other medical diagnoses) and the severity of their prostate cancer. Men in their 50s with aggressive cancer, for example, who had surgery or radiation were deemed to have received "high-benefit" treatment because it had the greatest impact on their life expectancy. By contrast, much older men with non-aggressive cancers would have been assessed as "low" benefit for aggressive prostate cancer treatments because these treatments would have had little impact on how long they lived.

Researchers focused on VHA data because it's the nation's largest provider of cancer care.

Prostate cancer remains the second-leading cause of cancer death among American men, with more than 34,000 dying annually from the disease. The U.S. National Cancer Institute estimates that 248,000 men will be diagnosed with prostate cancer in 2021, most in its earliest stages.

Scientists have for the first time detected black holes eating neutron stars, "like Pac Man", in a discovery documenting the collision of the two most extreme and enigmatic objects in the Universe.

The Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and the Virgo gravitational-wave observatory in Italy have captured the gravitational waves from the death spiral and merger of a neutron star with a black hole, not once but twice. The findings are published today.

The researchers say their observations will help unlock some of the most complex mysteries of the Universe, including the building blocks of matter and the workings of space and time.

More than 1,000 scientists were involved with the world-first detections, with many from Australia, including The Australian National University, leading the way.

Distinguished Professor Susan Scott, a co-author on the study based at the ANU Research School of Physics in the Centre for Gravitational Astrophysics, said the events occurred about a billion years ago but were so massive that we are still able to observe their gravitational waves today.

"These collisions have shaken the Universe to its core and we've detected the ripples they have sent hurtling through the cosmos," she said.

"Each collision isn't just the coming together of two massive and dense objects. It's really like Pac-Man, with a black hole swallowing its companion neutron star whole.

"These are remarkable events and we have waited a very long time to witness them. So it's incredible to finally capture them."

One event included a black hole with a mass nine times bigger than our own sun and a neutron star with two times our sun's mass. The other event included a black hole with about six times the mass of our sun and a neutron star with 1.5 times its mass.

Professor Scott, also a Chief Investigator at the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), said the international team had previously captured many events involving two black holes colliding as well as two neutron stars smashing together.

"Now, we've completed the last piece of the puzzle with the first confirmed observations of gravitational waves from a black hole and a neutron star colliding," she said.

Dr Johannes Eichholz, from the ANU Centre for Gravitational Astrophysics and an Associate Investigator with OzGrav, said the two detections were originally made on 5 and 15 January 2020.

"These kind of detections are incredibly rare," he said.

"We haven't detected these events once - but twice and within 10 days of each other.

"Like the ripples from these two events, which have been felt a billion years later, these findings will have a profound impact on our understanding of the Universe for many years to come."

For the first time, researchers have confirmed the detection of a collision between a black hole and a neutron star. In fact, the scientists detected not one but two such events occurring just 10 days apart in January 2020. The extreme events made splashes in space that sent gravitational waves rippling across at least 900 million light-years to reach Earth. In each case, the neutron star was likely swallowed whole by its black hole partner.

Gravitational waves are disturbances in the curvature of space-time created by massive objects in motion. During the five years since the waves were first measured, a finding that led to the 2017 Nobel Prize in Physics, researchers have identified more than 50 gravitational-wave signals from the merging of pairs of black holes and of pairs of neutron stars. Both black holes and neutron stars are the corpses of massive stars, with black holes being even more massive than neutron stars.

Now, in a new study, scientists have announced the detection of gravitational waves from two rare events, each involving the collision of a black hole and a neutron star. The gravitational waves were detected by the National Science Foundation's (NSF's) Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States and by the Virgo detector in Italy. The KAGRA detector in Japan, joined the LIGO-Virgo network in 2020, but was not online during these detections.

The first merger, detected on January 5, 2020, involved a black hole about 9 times the mass of our sun, or 9 solar masses, and a 1.9-solar-mass neutron star. The second merger was detected on January 15, and involved a 6-solar-mass black hole and a 1.5-solar-mass neutron star. The results were published today, June 29, in The Astrophysical Journal Letters.

Astronomers have spent decades searching for neutron stars orbiting black holes in the Milky Way, our home galaxy, but have found none so far. "With this new discovery of neutron star- black hole mergers outside our galaxy, we have found the missing type of binary. We can finally begin to understand how many of these systems exist, how often they merge, and why we have not yet seen examples in the Milky Way," says Astrid Lamberts, a CNRS researcher at Observatoire de la Côte d'Azur, in Nice, France.

The first of the two events, GW200105, was observed by the LIGO Livingston and Virgo detectors. It produced a strong signal in the LIGO detector but had a small signal-to-noise in the Virgo detector. The other LIGO detector, located in Hanford, Washington, was temporarily offline. Given the nature of the gravitational waves, the team inferred that the signal was caused by a black hole colliding with a 1.9-solar-mass compact object, later identified as a neutron star. This merger took place 900 million light-years away.

"Even though we see a strong signal in only one detector, we conclude that it is real and not just detector noise. It passes all our stringent quality checks and sticks out from all noise events we see in the third observing run," says Harald Pfeiffer, group leader in the Astrophysical and Cosmological Relativity department at Max Planck Institute for Gravitational Physics (AEI) in Potsdam, Germany.

Because the signal was strong in only one detector, the location of the merger on the sky remains uncertain, lying somewhere in an area that is 34,000 times the size of a full moon.

"While the gravitational waves alone don't reveal the structure of the lighter object, we can infer its maximum mass. By combining this information with theoretical predictions of expected neutron star masses in such a binary system, we conclude that a neutron star is the most likely explanation," says Bhooshan Gadre, a postdoctoral researcher at the AEI.

The second event, GW200115, was detected by both LIGO detectors and the Virgo detector. GW200115 comes from the merger of a black hole with a 1.5-solar mass neutron star that took place roughly 1 billion light-years from Earth. Using information from all three instruments, scientists were better able to narrow down the part of the sky where this event occurred. Nevertheless, the localized area is almost 3,000 times the size of a full moon.

Astronomers were alerted to both events soon after they were detected in gravitational waves and subsequently searched the skies for associated flashes of light. None were found. This is not surprising due to the very large distance to these mergers, which means that any light coming from them, no matter what the wavelength, would be very dim and hard to detect with even the most powerful telescopes. Additionally, the mergers likely did not give off a light show in any case because their black holes were big enough that they swallowed the neutron stars whole.

"These were not events where the black holes munched on the neutron stars like the cookie monster and flung bits and pieces about. That 'flinging about' is what would produce light, and we don't think that happened in these cases," says Patrick Brady, a professor at University of Wisconsin-Milwaukee and Spokesperson of the LIGO Scientific Collaboration.

Previously, the LIGO-Virgo network found two other candidate neutron star-black hole mergers. One event called GW190814, detected August 14, 2019, involved a collision of a 23-solar-mass black hole with an object of about 2.6 solar masses, which could be either the heaviest known neutron star or the lightest known black hole. Another candidate event, called GW190426, and detected on April 26, 2019, was thought to possibly be a neutron star-black hole merger, but could also simply be the result of detector noise.

Having confidently observed two examples of gravitational waves from black holes merging with neutron stars, researchers now estimate that, within one billion light-years of Earth, roughly one such merger happens per month.

"The detector groups at LIGO, Virgo, and KAGRA are improving their detectors in preparation for the next observing run scheduled to begin in summer 2022," says Brady. "With the improved sensitivity, we hope to detect merger waves up to once per day and to better measure the properties of black holes and super-dense matter that makes up neutron stars."

Scientists at the University of Sydney and Japan's National Institute for Material Science (NIMS) have discovered that an artificial network of nanowires can be tuned to respond in a brain-like way when electrically stimulated.

The international team, led by Joel Hochstetter with Professor Zdenka Kuncic and Professor Tomonobu Nakayama, found that by keeping the network of nanowires in a brain-like state "at the edge of chaos", it performed tasks at an optimal level.

This, they say, suggests the underlying nature of neural intelligence is physical, and their discovery opens an exciting avenue for the development of artificial intelligence.

The study is published today in Nature Communications.

"We used wires 10 micrometres long and no thicker than 500 nanometres arranged randomly on a two-dimensional plane," said lead author Joel Hochstetter, a doctoral candidate in the University of Sydney Nano Institute and School of Physics.

"Where the wires overlap, they form an electrochemical junction, like the synapses between neurons," he said. "We found that electrical signals put through this network automatically find the best route for transmitting information. And this architecture allows the network to 'remember' previous pathways through the system."

ON THE EDGE OF CHAOS

Using simulations, the research team tested the random nanowire network to see how to make it best perform to solve simple tasks.

If the signal stimulating the network was too low, then the pathways were too predictable and orderly and did not produce complex enough outputs to be useful. If the electrical signal overwhelmed the network, the output was completely chaotic and useless for problem solving.

The optimal signal for producing a useful output was at the edge of this chaotic state.

"Some theories in neuroscience suggest the human mind could operate at this edge of chaos, or what is called the critical state," said Professor Kuncic from the University of Sydney. "Some neuroscientists think it is in this state where we achieve maximal brain performance."

Professor Kuncic is Mr Hochstetter's PhD adviser and is currently a Fulbright Scholar at the University of California in Los Angeles, working at the intersection between nanoscience and artificial intelligence.

She said: "What's so exciting about this result is that it suggests that these types of nanowire networks can be tuned into regimes with diverse, brain-like collective dynamics, which can be leveraged to optimise information processing."

OVERCOMING COMPUTER DUALITY

In the nanowire network the junctions between the wires allow the system to incorporate memory and operations into a single system. This is unlike standard computers, which separate memory (RAM) and operations (CPUs).

"These junctions act like computer transistors but with the additional property of remembering that signals have travelled that pathway before. As such, they are called 'memristors'," Mr Hochstetter said.

This memory takes a physical form, where the junctions at the crossing points between nanowires act like switches, whose behaviour depends on historic response to electrical signals. When signals are applied across these junctions, tiny silver filaments grow activating the junctions by allowing current to flow through.

"This creates a memory network within the random system of nanowires," he said.

Mr Hochstetter and his team built a simulation of the physical network to show how it could be trained to solve very simple tasks.

"For this study we trained the network to transform a simple waveform into more complex types of waveforms," Mr Hochstetter said.

In the simulation they adjusted the amplitude and frequency of the electrical signal to see where the best performance occurred.

"We found that if you push the signal too slowly the network just does the same thing over and over without learning and developing. If we pushed it too hard and fast, the network becomes erratic and unpredictable," he said.

The University of Sydney researchers are working closely with collaborators at the International Center for Materials Nanoarchictectonics at NIMS in Japan and UCLA where Professor Kuncic is a visiting Fulbright Scholar. The nanowire systems were developed at NIMS and UCLA and Mr Hochstetter developed the analysis, working with co-authors and fellow doctoral students, Ruomin Zhu and Alon Loeffler.

REDUCING ENERGY CONSUMPTION

Professor Kuncic said that uniting memory and operations has huge practical advantages for the future development of artificial intelligence.

"Algorithms needed to train the network to know which junction should be accorded the appropriate 'load' or weight of information chew up a lot of power," she said.

"The systems we are developing do away with the need for such algorithms. We just allow the network to develop its own weighting, meaning we only need to worry about signal in and signal out, a framework known as 'reservoir computing'. The network weights are self-adaptive, potentially freeing up large amounts of energy."

This, she said, means any future artificial intelligence systems using such networks would have much lower energy footprints.

What is unique about the study is the combination of interviews with current and former people in prison, custodial professionals, and healthcare providers to identify and understand barriers in delivering high-quality healthcare and support to those in custody. In addition, researchers gathered data on the number, types and stages of cancers diagnosed in patients within prisons.

Moving forward, the researchers believe that findings from this study will help inform prison cancer care policy and develop priorities for improving it within the prison system. The research was funded by the National Institute for Health Research (NIHR), the research partner of the NHS, public health and social care.

Jo Armes, Reader in Cancer Care and Lead for Digital Health at the University of Surrey, who led the interviews with patients and professionals, said: "People in prison have a right to receive the equivalent standard of care as they would in the community. It is very unclear whether this is the case due to the current systems of reporting.

"Not only is the prison population increasing, but the demographic is getting older, with implications for heightened risk of developing cancer. Appropriate strategies must be in place so those in custody can be diagnosed early and access care promptly, which will also ensure effective and efficient use of NHS resources."

Professor Jo Rycroft-Malone, Director of the NIHR's Health Services and Delivery Research Programme, which funded the study, said: "This is an important area of research, and the first of its kind to investigate cancer care within English prisons, including the types and stages of the disease and the treatments available for prisoners.

"A key feature of this study is patient and public involvement - one of NIHR's key values - with former prisoners involved in research design and working as 'lived experience researchers', interviewing patients and professionals.

"This study aims to meet gaps in evidence in this area, and hopefully its findings will help improve the quality, accessibility and organisation of services for patients and assist clinicians and professionals working in prisons."

Pavan Dhaliwal, Chief Executive of Revolving Doors Agency, said: "People in contact with the criminal justice system often experience significant health inequalities -- a higher burden of disease and less access to health services. Addressing the health needs of this population can contribute to reducing inequalities in wider society.

"We are pleased to provide the lived-experience insight to this important work. People with lived- experience will bring unique perspectives, and this will, we hope, go a long way towards transforming healthcare services in prison."

Further results of the main study described in the paper will be published later in the year.

A long time ago, in two galaxies about 900 million light-years away, two black holes each gobbled up their neutron star companions, triggering gravitational waves that finally hit Earth in January 2020.

Discovered by an international team of astrophysicists including Northwestern University researchers, two events -- detected just 10 days apart -- mark the first-ever detection of a black hole merging with a neutron star. The findings will enable researchers to draw the first conclusions about the origins of these rare binary systems and how often they merge.

"Gravitational waves have allowed us to detect collisions of pairs of black holes and pairs of neutron stars, but the mixed collision of a black hole with a neutron star has been the elusive missing piece of the family picture of compact object mergers," said Chase Kimball, a Northwestern graduate student who co-authored the study. "Completing this picture is crucial to constraining the host of astrophysical models of compact object formation and binary evolution. Inherent to these models are their predictions of the rates that black holes and neutron stars merge amongst themselves. With these detections, we finally have measurements of the merger rates across all three categories of compact binary mergers."

The research will be published June 29 in the Astrophysical Journal Letters. The team includes researchers from the LIGO Scientific Collaboration (LSC), the Virgo Collaboration and the Kamioka Gravitational Wave Detector (KAGRA) project. An LSC member, Kimball led calculations of the merger rate estimates and how they fit into predictions from the various formation channels of neutron stars and black holes. He also contributed to discussions about the astrophysical implications of the discovery.

Kimball is co-advised by Vicky Kalogera, the principal investigator of Northwestern's LSC group, director of the Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Daniel I. Linzer Distinguished Professor of Physics and Astronomy in the Weinberg Colleges of Arts and Sciences; and by Christopher Berry, an LSC member and the CIERA Board of Visitors Research Professor at Northwestern as well as a lecturer at the Institute for Gravitational Research at the University of Glasgow. Other Northwestern co-authors include Maya Fishbach, a NASA Einstein Postdoctoral Fellow and LSC member.

Two events in ten days

The team observed the two new gravitational-wave events -- dubbed GW200105 and GW200115 -- on Jan. 5, 2020, and Jan. 15, 2020, during the second half of the LIGO and Virgo detectors third observing run, called O3b. Although multiple observatories carried out several follow-up observations, none observed light from either event, consistent with the measured masses and distances.

"Following the tantalizing discovery, announced in June 2020, of a black-hole merger with a mystery object, which may be the most massive neutron star known, it is exciting also to have the detection of clearly identified mixed mergers, as predicted by our theoretical models for decades now," Kalogera said. "Quantitatively matching the rate constraints and properties for all three population types will be a powerful way to answer the foundational questions of origins."

All three large detectors (both LIGO instruments and the Virgo instrument) detected GW200115, which resulted from the merger of a 6-solar mass black hole with a 1.5-solar mass neutron star, roughly 1 billion light-years from Earth. With observations of the three widely separated detectors on Earth, the direction to the waves' origin can be determined to a part of the sky equivalent to the area covered by 2,900 full moons.

Just 10 days earlier, LIGO detected a strong signal from GW200105, using just one detector while the other was temporarily offline. While Virgo also was observing, the signal was too quiet in its data for Virgo to help detect it. From the gravitational waves, the astronomers inferred that the signal was caused by a 9-solar mass black hole colliding with a 1.9-solar mass compact object, which they ultimately concluded was a neutron star. This merger happened at a distance of about 900 million light-years from Earth.

Because the signal was strong in only one detector, the astronomers could not precisely determine the direction of the waves' origin. Although the signal was too quiet for Virgo to confirm its detection, its data did help narrow down the source's potential location to about 17% of the entire sky, which is equivalent to the area covered by 34,000 full moons.

Where do they come from?

Because the two events are the first confident observations of gravitational waves from black holes merging with neutron stars, the researchers now can estimate how often such events happen in the universe. Although not all events are detectable, the researchers expect roughly one such merger per month happens within a distance of one billion light-years.

While it is unclear where these binary systems form, astronomers identified three likely cosmic origins: stellar binary systems, dense stellar environments including young star clusters, and the centers of galaxies.

The team is currently preparing the detectors for a fourth observation run, to begin in summer 2022.

"We've now seen the first examples of black holes merging with neutron stars, so we know that they're out there," Fishbach said. "But there's still so much we don't know about neutron stars and black holes -- how small or big they can get, how fast they can spin, how they pair off into merger partners. With future gravitational wave data, we will have the statistics to answer these questions, and ultimately learn how the most extreme objects in our universe are made."

Gravitational wave detectors have observed a new type of cataclysmic event in the cosmos: the merger of a neutron star with a black hole.

The phenomenon was detected twice in January 2020.

Several hypotheses could explain the existence of such mixed pairs. Further observations will be needed in order to settle the question.

Another missing piece has just been added to our knowledge of cosmic phenomena. The LIGO, Virgo and KAGRA collaborations have announced the first detection of gravitational waves (1) resulting from the 'mixed' merger between a black hole and a neutron star (2). The discovery, published on June 29, 2021 in Astrophysical Journal Letters, involves CNRS researchers working within the Virgo scientific collaboration.

Although it has only been only a few years since the very first observation of gravitational waves, the technique has yielded an extensive repertoire of phenomena involving massive cosmic objects. The LIGO and Virgo detectors have already observed mergers of pairs (or binaries) of black holes and, less frequently, of neutron stars. However, gravitational waves detected in January 2020 provide evidence of the existence of a new type of system. The signals, named GW200105 and GW200115 from their dates of detection, were produced by a process that had been predicted but never observed until now: the coalescence of 'mixed pairs' called NSBH pairs, each made up of a neutron star and a black hole (3).

Gravitational waves contain valuable information about their source, such as the mass of the components making up the binary. Analysis of the signals revealed that GW200105 resulted from the merger, some 900 million years ago, of a black hole and a neutron star, respectively 8.9 times and 1.9 times more massive than the Sun, while GW200115 originated from an NSBH pair which coalesced around 1 billion years ago, with masses 5.7 and 1.5 times greater than the Sun. The difference in mass between the components of the system indicates that they are indeed mixed binaries: the mass of the heavier object corresponds to that of a black hole while the mass of the lighter object is consistent with that of a neutron star. The difference between the two masses could also explain why no light signals were detected by telescopes. When a neutron star approaches a black hole it can theoretically be torn apart by tidal forces, causing flares of electromagnetic radiation. However, in the two cases observed, the black hole, being much more massive, could have gobbled up the neutron star in a single mouthful, leaving no trace.

Several hypotheses have been proposed to explain the formation of mixed NSBH binaries. The first involves the evolution of a pair of stars in orbit around one another. Towards the end of their lives, one of the stars could become a black hole and the other a neutron star, while still rotating around each other. According to another hypothesis, that of dynamic interaction, the two components of the pair form independently in a very dense stellar medium before coming together. These results open up the way for the detection of other mixed binaries, as well as for the observation and understanding of extreme phenomena of a similar nature.

Immunologists at McMaster University have discovered a previously unknown mechanism which acts like a spider web, trapping and killing pathogens such as influenza or SARS-CoV-2, the virus responsible for COVID-19.

The researchers have found that neutrophils, the most abundant white blood cells in the human body, explode when they bind to such pathogens coated in antibodies and release DNA outside of the cell, creating a sticky tangle which acts as a trap.

The findings, published online in the Proceedings of the National Academy of Science, are significant because little is understood about how antibodies neutralize viruses in the respiratory tract.

The discovery has implications for vaccine design and delivery, including aerosol and nasal spray technologies that could help the body head off infections before they have a chance to take hold.

"Vaccines can produce these antibodies that are present in our lungs, which are the first type of antibody to see viruses like flu or COVID-19, which infect our lungs and respiratory tracts," says the study's lead author Matthew Miller, an associate professor at McMaster's Michael G. DeGroote Institute for Infectious Disease Research and Canada's Global Nexus for Pandemics and Biological Threats. "Mechanisms that can stop the infection at the site where it enters our body can prevent the spread and serious complications."

By comparison, injectable vaccines are designed to bolster antibodies in the blood, but those antibodies are not as prevalent at the sites where infection begins.

"We should be thinking carefully about next generation COVID-19 vaccines that could be administered in the respiratory tract to stimulate antibodies. We don't have many candidates right now that are focused on raising the mucosal response," says Hannah Stacey, a graduate student in the Miller Lab and lead author of the paper, who recently won a major national scholarship from the Canadian Society for Virology for her work on COVID-19.

"If you want a lot of these antibodies that are really abundant in blood, then injections make the most sense, but if you want antibodies that are abundant in the respiratory tract, then a spray or an aerosol makes sense," she says.

Researchers caution that while the body's spider-web mechanism has the potential to be hugely beneficial, it can cause harm too, including inflammation and further illness when the web formation is uncontrollable.

They point to the early waves of the pandemic, prior to vaccinations, when these NETs, or neutrophil extracellular traps, were found in some patients' lungs, and had made their breathing more difficult.

"An immune response that is meant to protect you can end up harming you if it's not properly controlled," says Miller. "It's important to understand the balance of the immune system. If you have a lot of these antibodies before you get infected, they are likely going to protect you, but if the infection itself stimulates a lot of those antibodies it might be harmful."

INDIANAPOLIS - With the growing prevalence of chronic pain, depression, anxiety, and other symptom-based conditions, physicians and the healthcare systems for which they work are increasingly considering how to augment the care they can provide within the limited time allotted for patient appointments.

According to Regenstrief Institute Research Scientist Kurt Kroenke, M.D., writing in the Journal of General Internal Medicine (JGIM), collaborative care can and should play a major role targeting the treatment of symptoms and functional decline, both too frequently marginalized in medically oriented care delivery.

Collaborative care is a team-based model in which the patient's primary care physician is assisted in the management of specific health conditions (for example depression, anxiety or pain) by a care manager (often a nurse supervised by a physician specialist) with advanced expertise in the management of those conditions who provides care virtually.

Care managers help patients process information provided by their primary care physicians. For example, care managers can review treatment options, helping patients decide which option they prefer.

"We at Regenstrief and others have extensively studied utilizing collaborative care to provide behavioral treatments, education and care follow-up to patients with depression, anxiety and pain and we have found that it works," said Dr. Kroenke, a professor of medicine at Indiana University School of Medicine, an internationally respected pioneer in symptomology and the co-developer of the depression and anxiety scales most commonly used in primary care. "Collaborative care works because it provides patients with needed support between physician visits, augmenting medical practice via telephone or another telecare modality, making it easy for patients to fit into their schedules."

Collaborative care is becoming more common. Dr. Kroenke is currently exploring the use of collaborative care for substance abuse disorders.

"Perhaps the major reason that collaborative care hasn't gained traction outside of some large, integrated healthcare systems with multiple clinics, is because insurance companies typically have not covered augmenting physician care via telephone," said Dr. Kroenke. "But this barrier has eroded during the pandemic as telecare has been reimbursed by Medicare as well as insurance companies. And expanded use of telecare during the pandemic has also taught us to deliver virtual care more effectively and efficiently."

In addition to describing the collaborative care model and highlighting its application to patient care, "Canons of Collaborative Care" by Dr. Kroenke and Andrea Cheville, M.D., of the Mayo Clinic, provides principles for implementing collaborative care in real world clinical practice.

In a new scientific investigation headed by the German Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), water from African and Mongolian waterholes as well as bloodmeals from Southeast Asian leeches were assessed for the ability to retrieve mammalian viruses without the need to find and catch the mammals. The scientists analysed the samples using high throughput sequencing to identify known viruses as well as viruses new to science. Both approaches proved to be suitable tools for pandemic prevention research as they allow finding and monitoring reservoirs of wildlife viruses. For example, a novel coronavirus most likely associated with Southeast Asian deer species was identified. The results are published in the scientific journal "Methods in Ecology and Evolution".

Finding and monitoring reservoirs of wildlife viruses such as SARS-CoV-2 - for which the reservoir has yet to be discovered - is challenging. Many areas which wildlife inhabit are difficult to access and the species in question are hard to find or catch. In order to prevent future pandemics such as COVID-19, new and effective methods to discover and monitor viruses circulating in wildlife are urgently needed. Environmental DNA (eDNA) and invertebrate-derived DNA (iDNA) based approaches may enhance the available toolkit to overcome these challenges, when coupled with high throughput sequencing. The team of scientists assessed water from African and Mongolian waterholes and bloodmeals from Southeast Asian leeches for the ability to retrieve viruses from both sample types. The usual limitation of such samples is that they contain only tiny amounts of low-quality DNA, particularly pathogen DNA. The author therefore used a modern "hybridisation capture" approach to fish out sequences similar to those from currently known vertebrate viruses and then sequenced them using sophisticated high-throughput techniques. This approach was successful in that it allowed the identification of known and novel viruses in both water and leech samples.

The DNA from water samples yielded several viruses common to zebras and wild ass, which were expected as these animals frequently visit the waterholes in large numbers. In the case of the viruses found in African water holes, the authors demonstrated in a related publication that the viruses are still infectious, suggesting that the water itself may be a source of viral transmission. From the Southeast Asian leeches, many known as well as novel viruses were identified. Of particular interest was a novel coronavirus previously unknown to science, which potentially represents an entirely new genus in the Coronaviridae family and seems to be associated with deer species.

"For many of the deadliest viruses such as Ebola we still don't know where they come from", says Prof Alex Greenwood, head of the Department of Wildlife Diseases. "The current pandemic demonstrates that we still know very little about the viral diversity in nature. New methods might help us to identify novel viruses and their potential hosts without the usual logistical and ethical problems associated with collecting wildlife samples directly." Environmental DNA is proving useful in a number of contexts including the characterisation of the diversity of wildlife species from inaccessible regions, the study of ancient populations and more recently in pathogen research. Environmental DNA from water and DNA derived from blood-sucking invertebrates can be useful in different environments. "Water is an essential resource for life and, particularly in areas of seasonal shortages, a concentration point for animals", Greenwood says.

"Terrestrial leeches are often highly abundant in areas of previous viral emergence in Southeast Asia and their bloodmeals can be used to identify their mammalian hosts, including the pathogens contained in their blood", adds Dr Niccolò Alfano, a former PostDoc from the Leibniz-IZW Departments of Wildlife Diseases and Ecological Dynamics, now working at the University of Pavia in Italy. "We identified mammalian viruses from five different viral families in our leech samples and more than 50 % of the samples contained mammalian viruses. Some of these, such as a porcine circovirus or a bear annellovirus could be assigned to the bearded pig and sun bear, their mammalian hosts which were also detected in the leech samples. Most interesting was the discovery of the novel coronavirus, as this showed that with our method we are able to discover viral pathogens previously unknown to science circulating in wildlife", Alfano adds. This may help to identify potentially infectious viruses at an early stage which may help to prevent potential future epidemics."

Further work will be needed to characterise the newly discovered viruses, such as sequencing their complete genomes and confirming their host-virus relationships. In addition, waterholes or leeches are not found in all environments. Soil, faeces and other invertebrates represent additional sources of nucleic acids that could be used to supplement direct animal sampling and enhance our ability to discover and monitor viruses as we go forward from the current pandemic and hopefully learn to prevent them in the future.