Culture

ANN ARBOR--Long ago in a galaxy far, far away, fewer galaxies were born than expected--and that could create new questions for galaxy physics, according to a new University of Michigan study.

The study examined the satellite galaxies of Messier 94, or M94, a galaxy similar in size to our Milky Way. Researchers have long known the Milky Way has about 10 smaller, satellite galaxies surrounding it, each with at least a million stars, and up to more than a billion, such as the Magellanic Clouds.

Now, with the powerful Subaru telescope, astronomers can peer at galaxies five or 10 times the distance from the Milky Way, such as M94. They then can use the physics of how satellite galaxies form around the Milky Way to predict how many satellite galaxies a similar-sized galaxy such as M94 may have.

When U-M astronomers examined M94, they expected to find a similar number of satellite galaxies. However, they detected just two galaxies near M94, with very few stars each. Their results, led by Adam Smercina, a National Science Foundation fellow in the U-M Department of Astronomy, are published in the journal Astrophysical Letters.

"More than just an observational oddity, we show that the current crop of galaxy formation models cannot produce such a satellite system," Smercina said. "Our results indicate that Milky Way-like galaxies most likely host a much wider diversity of satellite populations than is predicted by any current model."

Smercina also says their results have implications for the current understanding of how galaxies form--which is in much larger halos of dark matter.

These halos of dark matter surrounding galaxies have immense gravitational force, and can pull in gas from their immediate vicinity. Large galaxies like the Milky Way generally form in halos of about the same mass. But these smaller satellite galaxies, which form in smaller 'subhalos,' are not nearly so dependable.

The production rate of high-mass stars in these satellite galaxies actually modulates their growth. If, for example, the nascent satellite galaxy forms too many high-mass stars at one time, their eventual supernova explosions might expel all its gas and halt all further growth. But astronomers are unsure at what size halo this 'scatter' in galaxy formation becomes important.

Smercina says M94 indicates that galaxy formation in intermediate-sized dark halos may be much more uncertain than previously thought.

"We think that that scatter--the range of galaxies we expect to see--may be a lot higher than what people currently think for dark matter halos of a certain mass," he said. "Nobody's under any illusions as to there being this huge scatter at the very lowest halo masses, but it's at these intermediate dark matter halos that the discussion is happening."

To observe the number of satellite dwarf galaxies around M94, the researchers took a composite image of the large galaxy. The image covered about 12 square degrees of the night sky--the full moon, for comparison, appears as about one square degree. This kind of image includes layers and layers of "noise," including cosmic rays and scattered light, which make faint dwarf galaxies difficult to detect.

To make sure they weren't missing satellite galaxies, Smercina and his team engineered artificial galaxies back into the image and recovered them using the same methods as for real satellites. With this technique, the researchers confirmed that were no more than two galaxies around M94.

"The real kicker is whether or not the community expected this could be possible," Smercina said. "That is the real curiosity of this finding--the result is something the simulations don't predict. When you can discover something we didn't really think we could find, you can make a contribution to our understanding of how our universe works, that's really rewarding."

Posttraumatic stress disorder (PTSD) was associated with cardiovascular disease and cancer, as well as the metabolic syndrome, in a new study.

In the Journal of Neuroscience Research study of 84 individuals diagnosed with PTSD (39 victims of terrorist attacks and 45 victims of other traumatic events), males were more likely to have circulatory and metabolic complications, whereas females had a higher prevalence of benign and malignant cancers.

A longer duration of PTSD was associated with the development of cardiovascular disease, while PTSD following terrorist attacks was associated with a higher cancer prevalence.

"An explanation of why victims of terrorism may have a higher cancer prevalence than victims of other traumatic events, such as accidents, may be the intentional infliction of harm on the victim causing a more dysregulated stress response. A challenge for the future is monitoring the physical health of victims over time and understanding psychological and neurobiological processes producing this effect," said co-author Dr. Andrea Pozza, of the Santa Maria alle Scotte University Hospital, in Italy. "Longer untreated PTSD was associated with higher prevalence of cardiovascular disease regardless of the event type: this suggests the importance of early intervention for PTSD and also education programs for the general population to make people aware about PTSD early warning signs and how to recognize them."

Aggressive prostate cancer, one of the leading causes of cancer deaths in men, is associated with BRCA2 mutations, which are also linked to hereditary breast cancer, ovarian cancer and pancreas cancer, among others. The finding was confirmed in a study, published in the Journal of Clinical Oncology, led by Elena Castro, Nuria Romero-Laorden and David Olmos, from the Prostate Cancer Clinical Research Unit at the Spanish National Cancer Research Centre (CNIO). It reveals that family members of patients with prostate cancer who carry BRCA2 and DNA-repair gene mutations have an increased risk of developing cancer and should be evaluated in familial cancer prevention programmes.

Furthermore, the new study shows that prostate cancer in men with BRCA2 mutations is associated with worse outcomes and poor responses to standard treatments. Researchers are currently assessing the benefits of ovarian and breast cancer therapies for prostate cancer patients.

The recently published article reports the first results of PROREPAIR-B, a study coordinated by CNIO researchers and conducted at the Instituto de Investigacion Biomedica de Malaga (IBIMA) and the Instituto de Genetica Medica y Molecular (INGEMM), with the participation of 38 Spanish hospitals. More than 400 men diagnosed with prostate cancer resistant to castration -- or hormone blockade -- were followed up for five years starting in 2013 in order to analyse their genetic characteristics and the impact of these on the progression of the disease and response to treatments.

"This is the first prospective study -- that is, not looking back in time but watching for outcomes from the moment patients are diagnosed with advanced cancer -- that shows BRCA2 mutations themselves, regardless of other factors, are responsible for poor prognosis and can have an impact on treatment responses," explains Castro, the article's first author.

"It should be noted that we identified germline mutations, although in a number of patients there were no familial cancer cases that might have indicated the presence of such genetic alterations. These mutations should be identified in patients with metastatic prostate cancer, since detecting such alterations is important for the diagnosis and management of the disease and for the patients' families, whose risk of developing breast, ovarian or pancreatic cancer is increased," explains Castro.

PROREPAIR-B is the first prospective cohort study carried out for a long period that involves a large number of patients diagnosed with metastatic prostate cancer castration resistant and with hereditary alterations.

"Our study shows that treatment and follow-up protocols used in patients with advanced prostate cancer may be inadequate for men with BRCA2 mutations. We are currently studying the characteristics that make these tumours more aggressive and trying to establish new strategies to improve patient prognosis," says David Olmos, Head of the CNIO Prostate Cancer Clinical Research Unit and coordinator of the project.

PROREPAIR-B: the genetics of the most aggressive prostate cancer

Prostate cancer is the most frequent cancer among males in Spain and Western countries, and the second most frequent worldwide. In recent years, survival has gradually increased as a result of early detection; however, it is the third most common cause of cancer deaths in men in Europe.

Most tumours are detected early, which improves prognosis. Advanced prostate cancer is usually treated with hormone therapy; however, a number of patients develop castration resistant prostate cancer. Some of these patients show poor responses to standard treatments. In general, survival in patients with resistance to androgen deprivation therapy is 3 years on average.

One of the main goals of PROREPAIR-B is to identify genetic markers associated to poor prognosis. In addition, understanding the genetic traits of aggressive tumours can help to explore novel treatment pathways.

The study focuses mainly on genetic patterns associated to deficiencies in DNA-repair mechanisms. Tumour cells carry many more genetic alterations than normal cells, which means they need highly effective repair mechanisms. According to Castro, her team "knew DNA repair is extremely important in prostate cancer. What we did not know was the proportion of patients in the population with advanced stage disease and hereditary mutations."

The study shows that 3% of the patients carry BRCA2 mutations, a percentage that reaches 16% when all DNA-repair genes are considered. "This proportion may seem comparatively low but it comprises a significant number of patients, given the high incidence of prostate cancer," says Castro.

A new treatment pathway

The researchers who participated in the study believe treatment strategies should be improved by optimising existing therapies and finding new drugs. In some patients, drugs interfering with DNA-repair mechanisms might be effective, as the cells that cannot repair their genetic defects die.

These drugs are PARP inhibitors, which have been approved for ovarian cancer and whose efficiency in prostate cancer is currently being tested in a number of clinical trials. Carboplatin is another drug that is currently being used to treat breast and ovarian cancers. The US Department of Defense has awarded funds to support a clinical trial carried out in Spain to demonstrate the effectiveness of carboplatin in patients with prostate cancer and DNA-repair defects.

January 9, 2018 - Astronauts who spend several months on the International Space Station have significant reductions in the size and density of paraspinal muscles of the trunk after returning to Earth, reports a study in Spine. The journal is published in the Lippincott portfolio by Wolters Kluwer.

Some changes in muscle composition are still present up to four years after long-duration spaceflight, according to the new research by Katelyn Burkhart, MS, of Massachusetts Institute of Technology and colleagues. They write, "Spaceflight-induced changes in paraspinal muscle morphology may contribute to back pain commonly reported in astronauts."

Trunk Muscles Show Decreased Area, Increased Fatty Tissue, after Months in Space

The researchers analyzed computed tomography (CT) scans of the lumbar (lower) spine in 17 astronauts and cosmonauts who flew missions on the International Space Station. Scans obtained before and after missions were analyzed to determine changes in the size and composition of the paraspinal muscles. Average time in space was six months.

Running up and down the spine, the paraspinal muscles play a key role in spinal movement and posture. Previous studies have found reduced paraspinal muscle mass after prolonged time in space, suggesting that muscle atrophy may occur without the resistance provided by gravity.

The CT scans showed reductions in the size of paraspinal muscles after spaceflight. For individual muscles, muscle size decreased by 4.6 to 8.8 percent. In follow-up scans performed one year later, size returned at least to normal for all muscles.

The scans also showed significant increases in the amount of fatty tissue present in the paraspinal muscles. Accordingly, the astronauts' muscle density, which is inversely related to fat content, decreased by 5.9 to 8.8 percent. For most muscles, composition returned to normal by one year.

However, for two muscles - the quadratus lumborum and psoas muscles - fat content remained above pre-flight values even two to four years after the astronaut returned from space. These muscles, which connect the spinal column to the pelvis, are located lateral (alongside) to the spinal column. By comparison, paraspinal muscles located posterior to (behind) the spinal column regained normal size and density.

Changes in muscle size and composition varied between individuals. For some muscles, changes in size were at least partly related to the amount and type of exercise the astronauts performed while in zero gravity: either resistance exercise or cycling. In-flight exercise did not seem to affect changes in muscle density.

Previous studies of astronauts have linked spaceflight to muscle atrophy, especially of the muscles that maintain posture and stability while upright on Earth in normal gravity. Many astronauts experience low back pain during and immediately after space missions, and they appear to be at increased risk of spinal disc herniation.

The new study is the first to measure changes in the size and density of individual paraspinal muscles. The results show that muscle size returns to normal upon Earth recovery, but that some changes in muscle composition - particularly increased fatty infiltration - may persist for at least a few years.

Some of the paraspinal muscle changes seem to be affected by exercise, suggesting possible approaches to preventing the adverse effects of prolonged spaceflight on spinal health and functioning. Ms. Burkhart and coauthors conclude, "As NASA plans for future missions to Mars and beyond, these results can be used to guide future countermeasures to mitigate declines in trunk muscle morphology and associated functional deficits."

The streams of electromagnetic energy released from a star destroyed by the tidal forces of a supermassive black hole nearly 290 million light years away encode valuable information about the physical properties of black holes, a new study finds. The results provide a new way to identify types of black holes that have been challenging to observe using other means. It's thought that a black hole lies at the center of nearly all massive galaxies. Most are inactive and do not produce any observable electromagnetic radiation, making them difficult to detect. Occasionally, however, the immense gravitational pull of these supermassive astronomical objects ensnares passing stars that stray too close - ripping them to pieces and casting the resulting debris into the maw. These stellar episodes, also known as tidal disruption events (TDE), are briefly observable through the electromagnetic energy, like X-rays, that is emitted and provide an opportunity to measure the defining characteristics of a black hole: mass and spin. While a black hole's mass can be inferred through the properties of its host galaxy, assessing its spin remains a challenge. According to the authors, energy emitted from stellar debris following a TDE could be used to determine a massive black hole's spin. Dheeraj Pasham and colleagues report on observations of ASASSN-14li, a TDE detected in 2014 by the All-Sky Automated Survey for Supernovae. Pasham et al. discovered that the X-rays emitted by TDE varied in a quasi-periodic oscillation every 131 seconds. Further analysis of the X-ray oscillation suggests that the stable, yet rapid rate of oscillation could only arise from stellar debris orbiting close to the black hole's event horizon and indicates that the black hole is rapidly spinning. Furthermore, the stable nature of the electromagnetic signal suggests that it is representative of the physical properties (i.e. mass and spin) of the black hole itself and not another transient astronomical event.

Maunakea, Hawaii - Astronomers have found a new exoplanet that could alter the standing theory of planet formation. With a mass that's between that of Neptune and Saturn, and its location beyond the "snow line" of its host star, an alien world of this scale was supposed to be rare.

Aparna Bhattacharya, a postdoctoral researcher from the University of Maryland and NASA's Goddard Space Flight Center (GSFC), led the team that made the discovery, which was announced today during a press conference at the 233rd Meeting of the American Astronomical Society in Seattle.

Using the Near-Infrared Camera, second generation (NIRC2) instrument on the 10-meter Keck II telescope of the W. M. Keck Observatory on Maunakea, Hawaii and the Wide Field Camera 3 (WFC3) instrument on the Hubble Space Telescope, the researchers took simultaneous high-resolution images of the exoplanet, named OGLE-2012-BLG-0950Lb, allowing them to determine its mass.

"We were surprised to see the mass come out right in the middle of the predicted intermediate giant planet mass gap," said Bhattacharya. "It's like finding an oasis in the middle of the exoplanet desert!"

"I was very pleased with how quickly Aparna completed the analysis," said co-author David Bennett, a senior research scientist at the University of Maryland and GSFC. "She had to develop some new methods to analyze this data - a type of analysis that had never been done before."

In an uncanny timing of events, another team of astronomers (which included Bhattacharya and Bennett) published a statistical analysis at almost the same time showing that such sub-Saturn mass planets are not rare after all.

"We were just finishing up the analysis when the mass measurements of OGLE-2012- BLG-0950Lb came in," said lead author Daisuke Suzuki of Japan's Institute of Space and Astronautical Science. "This planet confirmed our interpretation of the statistical study."

The teams' results on OGLE-2012-BLG-0950Lb are published in the December issue of The Astronomical Journal and the statistical study was published in the December 20th issue of the Astrophysical Journal Letters.

OGLE-2012-BLG-0950Lb was among the sub-Saturn planets in the statistical study; all were detected through microlensing, the only method currently sensitive enough to detect planets with less than Saturn's mass in Jupiter-like orbits.

Microlensing leverages a consequence of Einstein's theory of general relativity: the bending and magnification of light near a massive object like a star, producing a natural lens on the sky. In the case of OGLE-2012-BLG-0950Lb, the light from a distant background star was magnified by OGLE-2012-BLG-0950L (the exoplanet's host star) over the course of two months as it passed close to perfect alignment in the sky with the background star.

By carefully analyzing the light during the alignment, an unexpected dimming with a duration of about a day was observed, revealing the presence of OGLE-2012-BLG-0950Lb via its own influence on the lensing.

METHODOLOGY

OGLE-2012-BLG-0950Lb was first detected by the microlensing survey telescopes of the Optical Gravitational Lensing Experiment (OGLE) and the Microlensing Observations in Astrophysics (MOA) collaborations.

Bhattacharya's team then conducted follow-up observations using Keck Observatory's powerful adaptive optics system in combination with NIRC2.

"The Keck observations allowed us to determine that the sub-Saturn or super-Neptune size planet has a mass of 39 times that of the Earth, and that its host star is 0.58 times the mass of the Sun," said Bennett. "They measured the separation of the foreground planetary system from the background star. This allowed us to work out the complete geometry of the microlensing event. Without this data, we only knew the star-planet mass ratio, not the individual masses."

For the statistical study, Suzuki's team and MOA analyzed the properties of 30 sub-Saturn planets found by microlensing and compared them to predictions from the core accretion theory.

CHALLENGING THE THEORY

What is unique about the microlensing method is its sensitivity to sub-Saturn planets like OGLE-2012-BLG-0950Lb that orbit beyond the "snow line" of their host stars.

The snow line, or frost line, is the distance in a young solar system, (a.k.a. a protoplanetary disk) at which it is cold enough for water to condense into ice. At and beyond the snow line there is a dramatic increase in the amount of solid material needed for planet formation. According to the core accretion theory, the solids are thought to build up into planetary cores first through chemical and then gravitational processes.

"A key process of the core accretion theory is called "runaway gas accretion," said Bennett. "Giant planets are thought to start their formation process by collecting a core mass of about 10 times the Earth mass in rock and ice. At this stage, a slow accretion of hydrogen and helium gas begins until the mass has doubled. Then, the accretion of hydrogen and helium is expected to speed up exponentially in this runaway gas accretion process. This process stops when the supply is exhausted. If the supply of gas is stopped before runaway accretion stops, we get "failed Jupiter" planets with masses of 10-20 Earth-masses (like Neptune)."

The runaway gas accretion scenario of the core accretion theory predicts that planets like OGLE-2012- BLG-0950Lb are expected to be rare. At 39 times the mass of the Earth, planets this size are thought to be continuing through a stage of rapid growth, ending in a much more massive planet. This new result suggests that the runaway growth scenario may need revision.

Suzuki's team compared the distribution of planet-star mass ratios found by microlensing to distributions predicted by the core accretion theory.

They found that the core accretion theory's runaway gas accretion process predicts about 10 times fewer intermediate mass giant planets like OGLE-2012- BLG-0950Lb than are seen in the microlensing results.

This discrepancy implies that gas giant formation may involve processes that have been overlooked by existing core accretion models, or that the planet forming environment varies considerably as a function of host star mass.

NEXT STEPS

This discovery has not only called into question an established theory, it was made using a new technique that will be a key part of NASA's next big planet finding mission, the Wide Field Infra-Red Survey Telescope (WFIRST), which is scheduled to launch into orbit in the mid-2020s.

"This is exactly the method that WFIRST will use to measure the masses of the planets that it discovers with its exoplanet microlensing survey. Until WFIRST comes online, we need to develop this method with observations from our Keck Key Strategic Mission Support (KSMS) program as well as observations from Hubble," said Bennett.

"It's very exciting to see Keck and Hubble combine forces to provide this surprising new result," said Keck Observatory Chief Scientist John O'Meara. "And it's equally exciting to know that we can make these kind of advances today to help facilitate the best science from WFIRST and Keck's partnership in the future."

The NASA Keck KSMS program will continue to make follow-up observations of microlensing events detected by telescopes on the ground and in space.

A diving beetle demonstrating various adaptations to the life underground, including depigmentation and evolutionary loss of eyes, was discovered at the bottom of a clay pound in the cave Soprador do Carvalho, Portugal. The species turned out to be the very first in the whole order of beetles (Coleoptera) to be known exclusively from the underground waters of the country.

Despite not being able to find any other specimens during their study - save for the single female, the team of Dr Ignacio Ribera, Institute of Evolutionary Biology (Spain) and Prof Ana Sofia P. S. Reboleira, University of Copenhagen (Denmark) identified the beetle as new to science, thanks to its unambiguous morphology in combination with molecular data.

Aptly named Iberoporus pluto in reference to the ruler of the underworld in Greek mythology Pluto, the species was recently described in the open-access journal ZooKeys.

With a uniformly pale orange body measuring 2.8 mm in length and 1.1 mm in its widest part, the beetle is larger than the rest species known in its genus, and its appendages are longer and more slender. While blindness and depigmentation are clear adaptation to life away from sunlight, the elongated limbs and antennae reflect poor swimming abilities needed in a subterranean habitat. Going for 4 km in horizontal direction, Soprador do Carvalho is the largest in the Dueça cave system, located in the north-eastern part of the Sicó karst area in central Portugal. In recent years, the cave is being explored for tourism.

"The knowledge of the subterranean fauna from Portugal has significantly increased over the last decade, with the description of a high number of obligate subterranean species (tripling their number) and the establishment of new biogeographic patterns," explain the authors of the study. "A high number of these species are stygobiont (i.e. confined to groundwater), mostly from wells in the north of the country, where evapotranspiration is higher."

Depending on where you live, the buzz of a nearby mosquito can be a nuisance, or it can be deadly. Worldwide, more than 500 million people suffer from diseases transmitted by the blood-feeding insects, including malaria, Dengue Fever, Zika, and West Nile, and nearly a million deaths are attributed to mosquito-borne illnesses each year.

Researchers at the University of Arizona have discovered a protein in mosquitos that is critical to the process of producing viable eggs and could pave the way for "mosquito birth control." When researchers selectively blocked the activity of the protein - which they named Eggshell Organizing Factor 1, or EOF-1 - in female mosquitoes, the mosquitos laid eggs with defective egg shells, leading to the death of the embryos inside.

In the report, published in the open access journal PLoS Biology on Jan. 8, the team showed that EOF-1 exists only in mosquitoes. Therefore, any drug developed to render the protein dysfunctional would only affect mosquitoes and no other organisms.

The team, led by Jun Isoe, a research scientist in the lab of Roger Miesfeld, a UA Distinguished Professor and head of the Department of Chemistry and Biochemistry, is hopeful the approach might offer a way to interrupt mosquito egg formation and reduce mosquito populations in areas of human disease transmission without harming beneficial insects such as honey bees.

"We specifically looked for genes that were unique to mosquitoes and then tested for their functional role in eggshell synthesis," Isoe says. "We think there are other discoveries to be made using this same species-directed approach."

Isoe first used a bioinformatics approach to search for and identify genes that are unique to mosquitoes. None of those genes were previously known with regard to their function. The research team then created small RNA molecules that specifically inhibit each of the proteins the genes code for. Known as RNA interference, or RNAi, the technique works by suppressing messenger RNA molecules that serve as blueprints for proteins.

Focusing on the previously identified candidate genes one at a time, the RNAi molecules were injected into female mosquitoes right before a blood meal. Only female mosquitoes bite because they need a blood meal to produce eggs; the males visit flowers to drink nectar. Once a female mosquito has had a blood meal, her follicles develop and it takes three days to lay eggs.

Each individual mosquito was screened for viable offspring. Out of the 40 mosquito-specific genes the team tested, only one, the EOF-1 gene, was found to disrupt eggshell formation and result in the death of the mosquito embryo.

A female mosquito needs a second blood meal in order to produce next the batch of fertilized eggs. Usually, the effects of RNAi injection last only through one egg-laying cycle, but in the case of EOF-1, the researchers were surprised to find that treated females could no longer produce viable eggs for the rest of their two- to three-week life span, even after three consecutive blood meals.

"This lasting effect makes the EOF-1 protein a very attractive target for drugs," Miesfeld says.

Images obtained through electron microscopy revealed that when mosquitoes are deficient in the EOF-1 protein, the females lay eggs with abnormal-looking egg shells. Although the exact function of the protein remains to be elucidated, Isoe and Miesfeld believe that EOF-1 might act as a master switch at the onset of the insects' ability to produce viable eggs in response to a blood meal.

Based on these results, the team envisions a strategy using small molecule drugs that selectively interfere with mosquito EOF-1 in areas of the world where mosquito-borne human diseases are prevalent, resulting in eggs that never hatch into larvae.

"We think this strategy may have a much lower chance of harming other organisms than what is being used today," Miesfeld says. "Since the days of DDT, we have known that mosquito population control works to reduce the incidence of human disease. This could be a next-generation tool that could be applied to bed nets and other areas frequented by mosquitoes."

Of the more than almost 3,500 species of mosquitoes buzzing across all continents except Antarctica, three genera stand out as carriers of human disease: Mosquitoes of the genus Aedes transmit Yellow Fever, Dengue, Chikungunya and Zika viruses; West Nile virus is spread by Culex mosquitoes; and Anopheles mosquitoes are carriers of malaria. To ensure that disruption of EOF-1 was not specific to lab-bred mosquitoes, Isoe tested it on a strain of Aedes aegypti mosquitoes collected from wild populations in the Tucson area and found their eggs to be similarly affected.

"The inhibitors currently available to control mosquitoes have been used for so long that the pests are becoming resistant to them," Miesfeld says. "Our idea is to knock their populations down to a level where you can break the cycle of disease transmission between mosquitoes and humans."

As a first step toward turning the discovery into an application that could be commercialized, the team has filed a provisional patent on the species-specific discovery process through the UA's technology transfer office, Tech Launch Arizona.

A new device developed by Stanford University researchers could make it easier for doctors to monitor the success of blood vessel surgery. The sensor, detailed in a paper published Jan. 8 in Nature Biomedical Engineering, monitors the flow of blood through an artery. It is biodegradable, battery-free and wireless, so it is compact and doesn't need to be removed and it can warn a patient's doctor if there is a blockage.

"Measurement of blood flow is critical in many medical specialties, so a wireless biodegradable sensor could impact multiple fields including vascular, transplant, reconstructive and cardiac surgery," said Paige Fox, assistant professor of surgery and co-senior author of the paper. "As we attempt to care for patients throughout the Bay Area, Central Valley, California and beyond, this is a technology that will allow us to extend our care without requiring face-to-face visits or tests."

Monitoring the success of surgery on blood vessels is challenging as the first sign of trouble often comes too late. By that time, the patient often needs additional surgery that carries risks similar to the original procedure. This new sensor could let doctors keep tabs on a healing vessel from afar, creating opportunities for earlier interventions.

Flow or no

The sensor wraps snugly around the healing vessel, where blood pulsing past pushes on its inner surface. As the shape of that surface changes, it alters the sensor's capacity to store electric charge, which doctors can detect remotely from a device located near the skin but outside the body. That device solicits a reading by pinging the antenna of the sensor, similar to an ID card scanner. In the future, this device could come in the form of a stick-on patch or be integrated into other technology, like a wearable device or smartphone.

The researchers first tested the sensor in an artificial setting where they pumped air through an artery-sized tube to mimic pulsing blood flow. Surgeon Yukitoshi Kaizawa, a former postdoctoral scholar at Stanford and co-author of the paper, also implanted the sensor around an artery in a rat. Even at such a small scale, the sensor successfully reported blood flow to the wireless reader. At this point, they were only interested in detecting complete blockages, but they did see indications that future versions of this sensor could identify finer fluctuations of blood flow.

The sensor is a wireless version of technology that chemical engineer Zhenan Bao has been developing in order to give prostheses a delicate sense of touch.

"This one has a history," said Bao, the K. K. Lee Professor in the School of Engineering and co-senior author of the paper. "We were always interested in how we can utilize these kinds of sensors in medical applications but it took a while to find the right fit."

The researchers had to modify their existing sensor's materials to make it sensitive to pulsing blood but rigid enough to hold its shape. They also had to move the antenna to a location where it would be secure, not affected by the pulsation, and re-design the capacitor so it could be placed around an artery.

"It was a very exacting project and required many rounds of experiments and redesign," said Levent Beker, co-lead author of the paper and a postdoctoral scholar in the Bao lab. "I've always been interested in medical and implant applications and this could open up a lot of opportunities for monitoring or telemedicine for many surgical operations."

Making connections

The idea of an artery sensor began to take shape when former postdoctoral fellow Clementine Boutry of the Bao lab reached out to Anaïs Legrand, who was a postdoctoral fellow in the Fox lab, and connected those groups - along with the lab of James Chang, the Johnson and Johnson Professor of Surgery.

Once they set their sights on the biodegradable blood flow monitor, the collaboration won a 2017 Postdocs at the Interface seed grant from Stanford ChEM-H, which supports postdoctoral research collaborations exploring potentially transformative new ideas.

"We both value our postdoctoral researchers but did not anticipate the true value this meeting would have for a long-term productive partnership," said Fox.

The researchers are now finding the best way to affix the sensors to the vessels and refining their sensitivity. They are also looking forward to what other ideas will come as interest grows in this interdisciplinary area.

"Using sensors to allow a patient to discover problems early on is becoming a trend for precision health," Bao said. "It will require people from engineering, from medical school and data people to really work together, and the problems they can address are very exciting."

A protein required for development of mosquito eggs may provide a mosquito-selective target for insecticide development, according to a new study publishing on January 8 in the open-access journal PLOS Biology, by Jun Isoe of the University of Arizona and colleagues. Because the protein is specific to mosquitoes, it may be possible to interrupt their egg formation without harming other insects.

To find mosquito-specific proteins, the authors performed data mining and bioinformatic analyses of public genomic databases to identify protein-coding sequences that were restricted to the genomes of three of the most important vectors of human disease: Aedes, Culex, and Anopheles mosquitoes. Among other diseases, yellow fever is spread by Aedes species, West Nile fever by Culex, and malaria by Anopheles. They identified a group of genes expressed in mosquitoes but not in 37 evolutionarily closely related insects, and thus not likely to be found in other animals, plants, fungi, and bacteria.

Using a technique called RNAi, which inactivates messenger RNA and thus blocks expression of the targeted gene, the team investigated the role of 40 genes by blocking their expression in female Aedes aegypti mosquitos just prior to a blood meal, then analyzed the characteristics of the eggs they produced. They identified a protein, called eggshell organizing factor 1 (EOF1), whose inactivation led to fragile, non-melanized eggshells. The authors showed that loss of EOF1 caused multiple defects in egg structure, including a gross increase in size in a layer called the outer chorion. None of the eggs with deficient EOF1 were viable.

"Because EOF1 is restricted to mosquitoes, it may provide a useful target for developing more biosafe mosquito control strategies," Isoe said, "either with small-molecule inhibitors or CRISPR/Cas9 gene-drive genetic manipulation targeting this gene."

An international collaboration led by scientists from the National University of Ireland, Galway, The University of St Andrews, Trinity College Dublin and the Zoological Society of London has uncovered why the venom of some snakes makes them so much deadlier than others.

Snakes are infamous for possessing potent venoms, a fact that makes them deadly predators and also strikes fear into humans and other animals alike. However, some species, such as cobras, boomslangs and rattlesnakes have far more venom than they apparently need--in a single reserve of venom, they have the potential to kill thousands of their prey animals and several adult humans.

But not all venomous snakes are so dangerous. For example, the marbled sea snake has only a tiny amount of very weak venom, making it effectively harmless to any relatively large animals such as humans. Why venoms vary so much in their ability to kill or incapacitate potential prey animals has long puzzled scientists, with several competing hypotheses suggested as explanations.

The study, which has just been published in international journal Ecology Letters, tackled this puzzle by comparing records of venom potency and quantity for over 100 venomous snake species, ranging from rattlesnakes, cobras and the tree dwelling boomslangs of Africa to sea snakes and burrowing asps. The team found strong evidence that venoms have evolved to be more potent against animals that are closely related to the species that the snake commonly eats.

Dr Kevin Healy, who conducted the research at the University of St Andrews and is now Lecturer of Zoology at the National University of Ireland Galway, is the lead author of the study. He said: "These results make sense from an evolutionary viewpoint as we expect that evolution will have shaped venoms to be more efficient at killing the prey animals they are most often the target of the venom. You won't find many mice in the sea so we wouldn't expect a sea snake to evolve venom that is more effective at killing mice than fish."

The research also showed that the amount of venom a snake has depends on both its size and the environment it lives in.

"Like all substances venom is dosage-dependent," said Associate Professor in Zoology at Trinity College Dublin, Dr Andrew Jackson. "Even alcohol, coffee and water can be toxic at high enough volumes so we needed to consider how much venom different species of snake produce and store in their venom glands. We found that big terrestrial species have the most venom, while smaller tree dwelling or aquatic species had the least. This difference may be due to how often a snake encounters its prey in these different environments, with terrestrial species requiring a larger reserve of venom to take advantage of the rarer opportunities to feed."

The results of the study also have potential to aid in our understanding when it comes to human snakebites.

"Snakebites are a major health concern worldwide, with 2.7 million cases each year," commented Dr Chris Carbone of the Institute of Zoology in the Zoological Society of London. "Understanding how venom evolves may help us better identify the risks to humans from different snake groups, and also potentially from other venomous animals such as spiders, scorpions, centipedes and jellyfish."

The approach used in the study may also help researchers predict the potency of venoms in species that have yet to be tested, and even pinpoint potentially useful healthcare-related applications.

Dr Healy added: "The next step is to see how well this model may predict the potency of venoms in groups that have yet to have their venoms tested. By using ecological and evolutionary data for available species we may be able to use our approach as a tool to identify other species which may have properties in their venoms that are useful for biomedical purposes, such as drug development."

Caring for preterm babies in single family rooms appears to reduce the incidence of sepsis and improve exclusive breastfeeding rates compared with traditional open ward neonatal units, according to a systematic review and meta-analysis published in The Lancet Child & Adolescent Health journal.

Nevertheless, extremely preterm babies (

The authors say that the findings support the growing trend towards building more single family rooms in neonatal units. Sepsis (which affects around a quarter of babies born extremely preterm) and establishing breastfeeding during hospital stay are major challenges for preterm infants, and both are associated with cognitive outcomes in the long term [1]. However, they caution that the true effect of single family rooms on long-term cognitive outcomes remains unclear because of the small number and short follow-up of studies assessing neurodevelopment, and the lack of randomised controlled trials.

"Our findings support future development of single family rooms in neonatal units to reduce sepsis and improve breastfeeding rates during hospital stay. But to establish whether single rooms have an impact on long-term neurodevelopment we also need well-designed studies to examine the vast majority of preterm infants who are born after 32 weeks gestation, in whom no follow-up studies have been done", says Dr Sophie van der Schoor from OLVG (a teaching hospital in Amsterdam), Netherlands, who led the study. [2]

Prematurity is the main complication of pregnancy, and 14.9 million babies are born preterm (delivery before 37 weeks of gestation) worldwide every year. Delivery at any gestation other than full term can impair brain development, increasing the risk of poor neurocognitive outcomes.

Preterm babies often spend their first months after birth in neonatal intensive care units and are usually cared for communally in open bay units. Nurses provide routine care and parents are welcome in most units at any time. Concerns that unfavourable environmental factors including excessive stimulation from noise and lights, separation from parents, and infections may jeopardise neurodevelopmental outcomes and survival have contributed to a rise in hospitals building private rooms instead of open bay units. However, the potential benefits and harms that the hospital environment has on the health, particularly neurodevelopment, of preterm babies is hotly debated. Research so far has produced conflicting results.

The researchers based their findings on a systematic review and meta-analysis of all studies conducted in developed countries examining clinical outcomes of preterm infants cared for in single family rooms compared with open bay units between 2004 and 2018. Data were analysed for 13 distinct study populations (ie, infants from the same hospital admitted during the same time period) in 25 papers including 4,793 preterm babies. Data on neurodevelopment was available for three study populations, totalling 680 infants. Children were assessed for their cognitive, motor, and language development using a standardised test of infant development at the corrected age (for prematurity) of 18-24 months.

Analysis of data from these three study populations including only extremely preterm infants (average gestational age

Studies focusing on sepsis seemed to show a different picture, with significantly (37%) less risk of sepsis in single family rooms compared with open bay units (97/2055 participants vs 170/2110)--equivalent to one less sepsis event per 1000 hospitalisation days.

Nine studies (five populations) looking at breastfeeding found similar benefits--once discharged, babies cared for in single family rooms were 31% more likely to be exclusively breastfed compared to the open ward group (101/266 vs 68/218).

There were no differences in length of hospital stay (from birth to discharge home), rates of growth, bronchopulmonary dysplasia (a chronic lung disease), retinopathy of prematurity (a rare cause of blindness in premature babies), intraventricular haemorrhage (brain bleeding), or mortality.

"Although our study is based on all available data in the public domain, we did not find clear evidence of benefit of single family rooms on neurodevelopment. However, in all studies, outcomes were only assessed up to 2 years old, and some children who experience cognitive difficulties at school are classified as having normal neurodevelopmental function at 2 years of age. Even for cases of severe cognitive deficit at later ages in childhood the accuracy of early detection is low. As neuro-cognitive deficits often take a long time to develop, more and longer follow-up studies are needed", says van der Schoor. [2]

The authors note that the study included only one randomised trial and also point to several limitations, including that some papers assessed the same patient population, and without access to individual patient data it is difficult to get accurate effect estimates. They also highlight some methodological limitations including selection bias and confounding (only participants with potentially high parental presence during hospital stay were included or differences between populations might already have been present at start of the intervention)--which limit the conclusions that can be drawn.

Commenting on the implications of the study, Dr Jayanta Banerjee from Queen Charlotte's and Chelsea Hospital, London, UK says: "Van Veenendaal and colleagues have rightly argued that the benefits shown in their study should be considered by healthcare policy makers and stakeholders assessing future development of single family rooms in neonatal units. But single family rooms also have some inherent disadvantages. The parents might feel more isolated from other parents and health-care professionals when caring for their infants in single family rooms, which might have deleterious effects on their stress and anxiety. The staffing in a neonatal unit would require rearrangement to cater for single family room care. Finally, provision of single family rooms would require major restructuring in most neonatal units, which would have a substantial economic effect on health-care costs and resources. Therefore, when building new neonatal units or redeveloping existing units, single family rooms should be seriously considered."

More than half of female surgeons in the UK have faced or witnessed discrimination in the workplace, suggest the results of a confidential online poll, published in the online journal BMJ Open.

Orthopaedics was seen as the most sexist of all the surgical specialties, the responses showed.

Despite women making up over half of medical school entrants in the UK, less than a third opt for a career in surgery, which is widely acknowledged to be a male-dominated environment.

But few studies have looked at the way in which women feel their male surgical colleagues perceive them.

To address this, the researchers analysed the responses of 81 female surgeons to an online survey (42% response rate) about their perceptions and experiences of working in the field; what obstacles they had faced in their careers; and what they thought would help to overcome these.

The survey was distributed through the Association of Surgeons of Great Britain and Ireland (ASGBI) women in surgery Facebook page and shared on Twitter for two weeks in October 2017.

The ASGBI Facebook group is mainly made up of women (90%), aged between 25 and 34 (39%) and 35-44 (30%). Most surgeons in the group come from the UK (70%), but it also includes doctors from India, Pakistan, USA, Europe and Africa.

Analysis of the responses identified several perceived barriers to a surgical career for women: poor work-life balance; inflexibility over part-time careers; gender stereotyping; and lack of formal mentorship.

Most respondents (88%) felt that surgery remains male-dominated, with nearly six out of 10 (59%) reporting or witnessing discrimination against women in the workplace.

And around one in five (22%) felt that there was a "tangible glass ceiling," with an overriding feeling that the working culture is geared to men.

Orthopaedics was seen as the most sexist of the surgical specialties (53%), followed by cardiothoracic (16%) and general surgery (13%).

Half of the respondents agreed that motherhood and childcare commitments are the greatest obstacles for women wanting a career in surgery.

There is existing support for mothers working in surgery, but women are "presumed to deskill during maternity leave and are discouraged from working part time," say the researchers.

With fewer women represented at senior level, this could reinforce the idea that surgery is a male-dominated environment, they suggest.

But respondents felt that patients were often just as guilty of assuming women couldn't be surgeons: "Significantly more patients call me nurse or lady doctor than any of my colleagues," commented one.

Nearly a third (30%) of respondents said that sexist language should be challenged. Other suggestions for tackling discrimination included more female role models and mentors; destigmatisation of career breaks for women; flexible training/career options; better work-life balance; and improved understanding of the impact of childcare responsibilities on working life.

The study is based on a small online survey, so might not be representative of the female surgical workforce, the authors point out. But the poll nevertheless "illuminates the lived realities of female surgeons in the UK today," they suggest.

And with around 6 in 10 women reporting experience of discrimination, the responses suggest "an ancient culture pervading our society since the 1800s, at the time of the first female surgeon in the UK, Elizabeth Garrett," they write.

UNSW researchers at the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) have shown for the first time that they can build atomic precision qubits in a 3D device - another major step towards a universal quantum computer.

The team of researchers, led by 2018 Australian of the Year and Director of CQC2T Professor Michelle Simmons, have demonstrated that they can extend their atomic qubit fabrication technique to multiple layers of a silicon crystal - achieving a critical component of the 3D chip architecture that they introduced to the world in 2015. This new research was published today in Nature Nanotechnology.

The group is the first to demonstrate the feasibility of an architecture that uses atomic-scale qubits aligned to control lines - which are essentially very narrow wires - inside a 3D design.

What's more, the team was able to align the different layers in their 3D device with nanometer precision - and showed they could read out qubit states single shot, i.e. within one single measurement, with very high fidelity.

"This 3D device architecture is a significant advancement for atomic qubits in silicon," says Professor Simmons. "To be able to constantly correct for errors in quantum calculations - an important milestone in our field - you have to be able to control many qubits in parallel.

"The only way to do this is to use a 3D architecture, so in 2015 we developed and patented a vertical crisscross architecture. However, there were still a series of challenges related to the fabrication of this multi-layered device. With this result we have now shown that engineering our approach in 3D is possible in the way we envisioned it a few years ago."

In this paper, the team has demonstrated how to build a second control plane or layer on top of the first layer of qubits.

"It's a highly complicated process, but in very simple terms, we built the first plane, and then optimized a technique to grow the second layer without impacting the structures in first layer," explains CQC2T researcher and co-author, Dr Joris Keizer.

"In the past, critics would say that that's not possible because the surface of the second layer gets very rough, and you wouldn't be able to use our precision technique anymore - however, in this paper, we have shown that we can do it, contrary to expectations."

The team also demonstrated that they can then align these multiple layers with nanometer precision.

"If you write something on the first silicon layer and then put a silicon layer on top, you still need to identify your location to align components on both layers. We have shown a technique that can achieve alignment within under 5 nanometers, which is quite extraordinary," Dr Keizer says.

Lastly, the researchers were able to measure the qubit output of the 3D device with what's called single shot - i.e. with one single, accurate measurement, rather than having to rely on averaging out millions of experiments. "This will further help us scale up faster," Dr Keizer explains.

Towards commercialisation

Professor Simmons says that this research is a major milestone in the field.

"We are working systematically towards a large-scale architecture that will lead us to the eventual commercialisation of the technology.

"This is an important development in the field of quantum computing, but it's also quite exciting for SQC," says Professor Simmons, who is also the founder and a director of SQC.

Since May 2017, Australia's first quantum computing company, Silicon Quantum Computing Pty Limited (SQC), has been working to create and commercialise a quantum computer based on a suite of intellectual property developed at CQC2T and its own proprietary intellectual property.

"While we are still at least a decade away from a large-scale quantum computer, the work of CQC2T remains at the forefront of innovation in this space. Concrete results such as these reaffirm our strong position internationally," she concludes.