Culture

Magnetic Resonance Imaging (MRI) images are usually meant to be static. But now, researchers from Mātai Medical Research Institute (Mātai), Stevens Institute of Technology, Stanford University, the University of Auckland and other institutions, report on an imaging technique that captures the brain in motion in real time, in 3D and in stunning detail, providing a potential diagnostic tool for detecting difficult-to-spot conditions such as obstructive brain disorders and aneurysms - before they become life threatening.

The new technique, called 3D amplified MRI, or 3D aMRI, reveals pulsating brain movement which could help researchers to non-invasively visualise brain disorders and inform better treatment strategies for tiny deformations or disorders that obstruct the brain or block the flow of brain fluids.

Samantha Holdsworth, director of research at Mātai, senior lecturer at the University of Auckland and principle investigator at the Centre for Brain Research, and Mehmet Kurt, an assistant professor of mechanical engineering at Stevens Institute of Technology, have now published two papers on aMRI in collaboration with Stanford University, the University of San Diego California, Queens University, and the Icahn School of Medicine at Mount Sinai.

The first paper, published online today in Magnetic Resonance in Medicine, presents the 3D aMRI method, comparing it with its 2D aMRI predecessor. The new method results in a stunning visualization of the human brain's movement that can be seen in all directions. The second paper, published online today in Brain Multiphysics, visualizes, validates and quantifies both the amplitude and direction of the brain as it moves in three dimensional space. The validation and quantification ensures that the software processing reflects an amplified version of real movement.

The approaches reported in the two papers could hold important clinical insights for a number of brain disorders. For example, the abnormal motion of two areas at the base of the brain, the pons and cerebellum, has been proposed as a diagnostic marker of Chiari I malformation, an abnormality that causes brain tissue to extend into the spinal canal.

2D amplified MRI was developed by Holdsworth, Mahdi Salmani Rahimi, Itamar Terem and other collaborators at Stanford, enabling MRI imaging to capture brain motion in a way that had previously never been seen before. 3D amplified MRI builds on this previous work developed and published in 2016. The aMRI algorithm uses a video motion processing method developed by Neal Wadhwa, Michael Rubinstein, Fredo Durand, William Freeman and colleagues at Massachusetts Institute of Technology.

"The new method magnifies microscopic rhythmic pulsations of the brain as the heart beats to allow the visualization of minute piston-like movements, that are less than the width of a human hair," explained Terem, a graduate student at Stanford and lead author of the first paper. "The new 3D version provides a larger magnification factor, which gives us better visibility of brain motion, and better accuracy."

3D aMRI of the human brain shows minute movements of the brain at an unprecedented spatial resolution of 1.2mm3, approximately the width of a human hair. The actual movements are amplified (made larger, up to 25 times) to allow clinicians and researchers to view the movements in detail. The striking detail of these animated magnified movements may be able to help identify abnormalities, such as those caused by blockages of spinal fluids, which include blood and cerebrospinal fluid.

"We showed that 3D aMRI can be used for the quantification of intrinsic brain motion in 3D, which implies that 3D aMRI holds great potential to be used as a clinical tool by radiologists and clinicians to complement decision making for the patient's treatment," said Mehmet Kurt, from the Stevens Institute of Technology and senior author of the second paper. "In my lab at Stevens, we are already seeing the benefits of using variants of 3D aMRI technique in a variety of clinical conditions including Chiari Malformation I, hydrocephalus, and aneurysms, in collaboration with clinicians at Mount Sinai."

A number of research projects are underway using the new imaging software. Holdsworth said, "We are using 3D aMRI to see if we can find new insights into the effect of mild traumatic brain injury on the brain. She added, "One study already underway, a collaboration between Mātai and the University of Auckland, uses 3D aMRI together with brain modelling methods to see whether we can develop a non-invasive way of measuring brain pressure, which may in some cases remove the need for brain surgery". This could be valuable clinically, for example, in children with idiopathic intracranial hypertension who often require invasive brain pressure monitoring.

Miriam Sadeng, an associate professor at the University of Auckland in the department of anatomy and medical imaging, who is a physician and is an author on both papers said, "This fascinating new visualization method could help us understand what drives the flow of fluid in and around the brain. It will allow us to develop new models of how the brain functions, that will guide us in how to maintain brain health and restore it in disease or disorder."

"Validating the method through computational modelling gave us further confidence about the potential impact of this work," said Javid Abderezaei, a graduate student in Kurt's lab at Stevens and lead author on the second paper. "What is exciting to see is that the dominant displacement patterns in the healthy brain qualitatively matched with the underlying physiology, which means that any changes in the physiological flow as a result of a brain disorder should be reflected in the displacements we measure."

The capability to view the differences in brain motion could help us better understand a variety of brain disorders. In the future, the technology could be expanded to use in other health disorders throughout the body.

BIRMINGHAM, Ala. - Last year, Charles O. Elson, M.D., demonstrated a potential preventive treatment for Crohn's disease, a form of inflammatory bowel disease. He used a mouse model that included immune-reactive T cells from patients with Crohn's disease in a flagellin peptide-specific immunotherapy. This study provided proof-of-principle that a flagellin-directed immunotherapy might provide similar benefits in patients.

Now University of Alabama at Birmingham researchers have moved a step closer to possible clinical testing of this treatment, say Elson and co-first authors Katie Alexander, Ph.D., and Qing Zhao, M.D., Ph.D. Their study, published in the journal
Gastroenterology, is the first to describe IgG antibodies in Crohn's disease specific for human-derived flagellins of bacteria belonging to the Lachnospiraceae family. Knowledge of the specific flagellin epitopes that drive the pathogenic adaptive immune response in Crohn's disease is necessary information for Elson's potential triple-punch Crohn's disease treatment. Goals of the treatment are removing or exhausting pathogenic T memory cells and increasing the number of immunomodulatory T regulatory cells.

Elson is a professor, Alexander an assistant professor and Zhao a postdoctoral fellow in the UAB Department of Medicine Division of Gastroenterology and Hepatology.

Crohn's disease and ulcerative colitis -- another type of inflammatory bowel disease -- are characterized by dysregulated adaptive immune responses to the microbiota in genetically susceptible individuals, but the human specificity of these responses had so far been largely undefined. Mouse microbiota flagellins have previously been defined as immunodominant antigens in Crohn's disease.

Flagellins are building blocks of the hairlike motility flagella that extend from the bacterial cell wall. Flagellin is a potent immune activator and antigen, and it is the only known microbial protein that has three receptors for innate immunity encoded in the host genome, in addition to immunoglobulin and T cell receptors.

The UAB researchers individually probed blood sera from 87 healthy volunteers, 152 patients with Crohn's disease and 170 patients with ulcerative colitis. They used protein arrays of microbiota bacterial flagellins of both mouse and human origin, and they analyzed sera for IgG and IgA antibody responses.

They found selective patterns of antibody reactivity to microbiota flagellins among the inflammatory bowel disease patients.

The Crohn's disease patients -- but not the ulcerative colitis patients -- had augmented serum IgG antibodies to Lachnospiraceae flagellins from various species of Roseburia and one species of Eubacterium. These bacteria are normal residents in the human ileum, the third segment of the small intestine. A subset of the Crohn's disease patients had very high responses, with antibodies against more than 10 different flagellins.

For that subset of Crohn's disease patients, the multiflagellin hyper-reactivity was associated with indications of severe dysregulated immune response. Patients in the subset had: 1) elevated flagellin-specific T memory cells; 2) a reduced ratio of flagellin-reactive T regulatory to T effector cells; and 3) a high frequency of disease complications.

"Thus," Elson said, "Crohn's disease patients displayed a strong adaptive immune response to human-derived Lachnospiraceae flagellins, which may be targeted for prognosis and future personalized therapies."

Researchers have created a probe that glows when it detects an enzyme associated with issues that can lead to blood clots and strokes.

The team of researchers, from the Department of Chemistry and the National Lung and Heart Institute at Imperial College London, demonstrated that their probe quickly and accurately detects the enzyme in modified E. Coli cells.

They are now expanding this proof-of-concept study, published in the Journal of the American Chemical Society and funded by the British Heart Foundation (BHF), with the hope of creating rapid tests for cardiovascular problems and a new way to track long-term conditions.

The build-up of plaque in the arteries - known as atherosclerosis - can lead to coronary artery disease and stroke, and is one of the leading causes of death in the Western world.

As atherosclerosis progresses, intraplaque haemorrhages (IPHs) can occur when portions of the plaque break away from the artery walls. These events can lead to the formation of more vulnerable plaques and blood clots, restricting blood flow to the heart and the brain and potentially leading to chronic diseases or catastrophic events like strokes.

Detecting IPHs and their impacts would therefore provide a warning system and allow early diagnosis of vascular conditions. The research team designed a chemical probe that can detect rises in levels of an enzyme that accompanies IPHs and even plaque instabilities that precede IPHs.

Study co-lead Professor Nicholas Long, from the Department of Chemistry at Imperial, said: "Progress in the field of early cardiovascular disease has been rather limited and slow-paced but this new probe, and others that we are developing, will go a long way to addressing this by providing real-time and easily measured responses to diagnostic enzymes."

Study co-lead Dr Joe Boyle, from the National Heart and Lung Institute, added: "Ultimately, these probes could provide the basis for diagnostic tests at the GP, ambulances or in hospitals for quick identification of cardiovascular diseases. The probes could also provide real-time analysis of the underpinning biological processes involved in vascular disease, providing new insights and potentially new ways to track the progress of chronic disease."

The team's probe works by detecting an enzyme that is released in large quantities during IPHs, called heme oxygenase-1 (HO-1). Previous attempts to screen for HO-1 have been unreliable and cannot be used to detect real-time changes, but the new probe addresses both these issues.

The probe is made up of two components that can host fluorescent (glowing) molecules - one 'donor' that transfers the fluorescent molecules to the 'acceptor' component. When the probe comes into contact with HO-1, the bond between the two components is severed, leading to the build-up of the fluorescent molecules in the donor component.

This build-up causes an increase in the fluorescence intensity of the probe that can be detected using spectroscopy. In tests using modified E. coli cells containing human HO-1, the team detected a six-fold increase in the fluorescence of the probe.

Professor James Leiper, associate medical director at the BHF, said: "Current methods to detect IPH rely on hospital-based imaging techniques that are both time consuming and expensive. The current technology aims to produce a fast and sensitive diagnostic test that can be used at the time that a patient first presents with symptoms to allow early detection of IPH. Use of such a test would allow for more rapid treatment and improved outcomes for patients suffering from IPH."

The team are now extending their studies to mammal and human cells. They have recently patented their probe and have received funding from the British Heart Foundation to make a new generation of probes for other cardiovascular and neurodegenerative diseases, and to carry out more in-depth biological investigations of the underlying mechanisms.

Biodiversity is of crucial importance to the marine ecosystem. The prohibition of trawling activities in the Hong Kong marine environment for two and a half years has significantly improved biodiversity, an inter-university study led by City University of Hong Kong (CityU) has found. Research results showed that the trawl ban could restore and conserve biodiversity in tropical coastal waters.

The research team was led by Professor Kenneth Leung Mei-yee, CityU's Director of the State Key Laboratory of Marine Pollution (SKLMP) and Chair Professor in the Department of Chemistry. The findings were published in the journal Communications Biology, titled "Recovery of tropical marine benthos after a trawl ban demonstrates linkage between abiotic and biotic changes".

Trawling captures animals of all sizes

Trawling is the practice of dragging fishnets across the seabed to sweep up fishes. "Trawlers capture animals of all sizes and cause severe damages to the seabed. Also, trawling raises plumes of sediment from the seabed and induces their suspension in the water. Therefore, organisms living on the seabed which feed on those sediments would be lack of food, and biodiversity loss has resulted," said Professor Leung.

Since 31 December 2012, the Hong Kong SAR Government has implemented a territory-wide trawling ban in Hong Kong waters with the hope of rehabilitating the marine benthic habitat. To investigate whether such intervention can facilitate ecosystem recovery, the research team led by Professor Leung collected sediment samples with five replicates from each of 28 locations in Hong Kong waters in June 2012 (half-year before the trawl ban) and two and a half years after the trawl ban and then examined for physicochemical properties of the sediment and diversity of benthic animals (usually live at the bottom of a body of water).

Substantial increases in richness of species and abundance of benthic marine organisms

The results of this study suggested the trawling ban has reduced pressure on the marine environment from fishing and has led to substantial increases in the richness of species and the abundance of benthic marine organisms.

Compared to the survey conducted in 2012, the average amount of suspended solids was reduced by 1.36 mg/L, a reduction of about 25%, in the water column while the average amount of total organic matter was increased by 1.6 mg/L (an increase of about 29%) in surface sediment after the ban, indicating decreased disturbance on marine benthic habitats.

In addition, there were significant increases in abundance and species richness of benthic organisms after the ban. The average number of benthic species found in sediment samples increased from 27.5 to 48.3 species (an increase of 76%). In each 0.5 m2 of the sampling area, the average amount of all benthic organisms found in sediment samples increased from 253 to 848 individuals (an increase of 235%). Such increases were more prominent in polychaete worms and bivalves.

Rapid recovery in benthic marine ecosystem

"These small benthic organisms actually play a very crucial role as they are the main source of food for fishes, crabs and mantis shrimps. Because of the trawl ban, their abundance increases lead to an increase in the abundance of the bigger creatures, hence rehabilitating the fisheries resources," said Professor Qiu Jianwen from Hong Kong Baptist University (HKBU), one of the corresponding authors of this paper and a member of SKLMP.

Parallel studies conducted by the team revealed that fish and crustacean stocks in eastern and western waters in Hong Kong had recovered after comparing their diversity before (2004 and 2012) and after the trawl ban (2013 to 2016). It is revealed that in each km2 sampling area, the average number of predatory crabs increased 5 times from 86 in 2004 to 516 individuals in 2015 to 2016 in eastern waters, while in western waters, the number of predatory crabs greatly increased 12 times from 157 to 2101 individuals. Similarly, the number and weight of all fishes or all predatory fishes also increased in eastern and western waters after the trawl ban.

"After the trawl ban, the mantis shrimps samples we collected were longer and heavier than the previous ones. Moreover, the biomass of fish and crustaceans in the eastern and western waters has increased, which is encouraging. Our study suggested a rapid recovery of Hong Kong's benthic ecosystem and the fisheries resources in 3.5 years after the trawl ban," stressed Professor Leung.

The team conducted over 100 times of on-site survey. A postdoctoral fellow, 4 PhD students and a master student helped in the species identification and numeration of a large number of samples, as well as data processing and analysis.

Multi-pronged approach to promote ecosystem restoration

"Our results are highly encouraging and supportive of the Hong Kong SAR Government's trawl ban policy. Gratifyingly, Hong Kong has provided such a good example of successful management intervention for promoting sustainable fisheries development and marine biodiversity conservation. We hope that other countries, especially those in the tropics, will refer to our study and join forces to prohibit destructive trawling activities," said Professor Leung.

He described this study as "rare but essential" because their investigation only represented the second trawl ban study carried out in the tropics among the 71 relevant studies in the world. He hoped that the results of this research could draw the attention of governments around the world to the impact of trawl fishing on marine ecosystems. After the paper was published, Professor Leung was invited by Sciaena, a marine science and cooperation organisation in Portugal, to share the findings. He was also interviewed by the staff of the Food and Agriculture Organization of the United Nations.

"Apart from trawl ban, a multi-pronged approach can promote ecosystem restoration. For example, stop illegal trawling by increasing enforcement, improve water quality, impose a fish moratorium, control fishing gears, restrict the size of harvested fishes, establish fishery protection areas, and also minimise marine construction works," elaborated Professor Leung.

Machine learning algorithms can leverage vast amounts of consumer data, allowing automation of business decisions such as pricing, product offerings, and promotions. Airbnb, an online marketplace for vacation rentals and other lodging, created an algorithm-based smart-pricing tool that is free to all Airbnb hosts and allows hosts to set their properties' daily price automatically. A new study investigated the impact of Airbnb's algorithm on racial disparities among Airbnb hosts. Adopting the tool narrowed the revenue gap between White and Black hosts considerably, but because far fewer Black hosts used the algorithm, the revenue gap between White and Black hosts actually increased after the tool's introduction.

The study, by researchers at Carnegie Mellon University (CMU), is forthcoming Marketing Science.

"The disparity in revenues earned by White and Black hosts has been the subject of a lot of negative publicity for Airbnb in the last few years," explains Param Vir Singh, Professor of Business Technologies and Marketing at CMU's Tepper School of Business, who led the study. "Our results show that a smart-pricing algorithm can be effective in mitigating racial disparities, but that effectiveness is limited by the extent to which the tool is adopted."

The pricing algorithm was introduced in November 2015, and the study ran from July 2015 to August 2017. Researchers randomly selected 9,396 Airbnb properties in 324 zip codes, primarily in seven large U.S. cities; 2,118 hosts adopted the algorithm during the study. Researchers looked at each property's average daily revenue by month. Hosts' race/ethnicity (White, Black, or other) was determined from profile photos of host pages.

Prior to the introduction of the algorithm, White hosts earned $12.16 more in daily revenues than Black hosts after controlling for other observed host, property, and neighborhood characteristics. While both Black and White hosts charged similar prices for their properties, demand for rentals hosted by Black hosts was 20% less than that for White hosts. This suggests the presence of racial biases among Airbnb guests against Black hosts, the researchers concluded.

Adopting the algorithm benefited Black hosts in the study more than White hosts, according to the study. This is because it led to a much larger increase in demand for rentals hosted by Black hosts than for rentals hosted by White hosts, largely because demand for rentals hosted by Black hosts was more responsive to price changes than that for rentals hosted by White hosts.

But Black hosts were 41% less likely than White hosts to adopt the algorithm. Thus, while adopting the tool narrowed the revenue gap between White and Black hosts in the study, when researchers applied their findings at the population level, the revenue gap increased.

Even though Black and White hosts faced different demand curves, the price suggested by the algorithm was the same across Black and White hosts. This is because the algorithm pools the data of Black and White hosts to determine the same optimal price for both groups, in effect, ignoring racial differences between hosts. As a result, although the optimal price suggested by the algorithm should lie between the optimal price for Black hosts and the optimal price for White hosts, since fewer Black hosts adopted the algorithm, the suggested optimal price is likely to be closer to the optimal price for White hosts and farther than that for Black hosts.

"Our study has implications for policymakers and managers," says Kannan Srinivasan, Professor of Management, Marketing, and Business Technologies at CMU's Tepper School, who coauthored the study. "For policymakers, our study shows that when racial biases exist in the marketplace, an algorithm that ignores those biases may not succeed in reducing racial disparities.

"Given the much lower rate of adoption of the algorithm by Black hosts than White hosts, managers may want to devise strategies to encourage Black hosts to adopt the algorithm," Shunyuan Zhang, Assistant Professor of Marketing at Harvard Business School and co-author added. "Otherwise, an algorithm that could reduce disparities may end up increasing them."

An Austrian-American research team (University of Vienna, Department Evolutionary Anthropology and Harvard Medical School, Department of Genetics), in collaboration of Hungarian experts from Eötvös Loránd University, has developed a new method that allows the almost non-destructive extraction of genetic material from archaeological human remains. The method allows anthropologists, archaeologists and archaeogeneticists to avoid the risk of serious damage to artefacts of significant scientific and heritage value, which can then be fully examined in future research.

Bioarcheological research on human and animal remains from archaeological excavations has become increasingly important in recent decades. Both nationally and internationally, in addition to classical archaeological and anthropological research, a significant number of molecular biological way of examination are included. One of the most important fields is archaeogenetics. The study of ancient human and animal genetic material can significantly help both the analysis of human evolution and the answering of historical questions about the populations of later archaeological periods.

The first archaic DNA (aDNA) research started in the 1980s, but the real methodological breakthroughs came after the turn of the millennium. This was the period when next-generation sequencing methods reached bioarcheological research. Thanks to the large-scale research that began at that time, we now know more than 60% of the DNA of Neanderthals preserved in the nuclei of cells. A new human species was described on the basis of the genetic material extracted from teeth and finger bones found in Siberia, and it was recognised that, contrary to previous ideas, Neanderthal man and modern Homo sapiens interbred with each other, that left significant genetic traces in modern human groups north of the Sahara.

However, these samples for archaeogenetic analyses may involve a high degree of destruction and may therefore be of concern from a heritage conservation perspective, preventing or making it difficult to obtain and carry out the sampling.

An international team of researchers (Ron Pinhasi laboratory at the University of Vienna and David Reich' laboratory at Harvard) has recognised this problem and has recently developed several new sampling methods to minimise the bone damage associated with sampling. Firstly, the methodological basis for drilling into the inner ear from the cranial base was developed and later it was shown that the use of auditory ossicles can significantly reduce the damage in the fining during sampling.

The latest research, published in the journal Genome Research, was carried out by the above-mentioned international team and the researchers of the Department of Anthropology (Tamás Hajdu, Krisztián Kiss, Tamás Szeniczey) and the Institute of Archaeology (Alexandra Anders, Pál Raczky) at Eötvös Loránd University.

„The new method significantly reduces the extent of damage of the findings. It consists of dissolving the DNA content of the root fragment of the tooth, rich in cellular cementum, by immersing it in a special solution. The quality of the sample thus obtained is not as good as that of DNA extracted from the inner ear, but it is of the same quality as that of the genetic material obtained by traditional methods (drilling and pulverisation of the tooth). The main advantage of the method is that the tooth undergoes only to minimal damage, leaving its structure intact not only morphologically but also histologically, while its unchanged chemical composition allows subsequent isotopic tests (strontium or C14) to be carried out. The only noticeable change is the fading or whitening of the root colour" - told Tamas Hajdu, head of the Hungarian research group, Assistant Professor at the Department of Anthropology at Eötvös Loránd University.

The significance of the new sampling method, therefore, lies in its minimal destructive effect. If the sampled teeth are left intact, they can be subjected to further morphological, radiological, histological, oral pathological, stable isotope and radiocarbon studies. This may be particularly important in cases where only a few teeth remain have been preserved from a given period and place, which may be tens of thousands of years old, and destructive sampling of these would completely preclude subsequent analysis. In addition to human evolutionary research, the new methodology could also help projects on population history and disease evolution at the Department of Anthropology and the Institute of Archaeology, at Eötvös Loránd University by preserving the integrity of the findings. The new sampling method, developed in international cooperation, offers a new perspective for the preservation of artefacts for national and international museum institutions, while at the same time allowing for the almost non-destructive conduct of the latest archaeogenetic analyses.

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The international team of researchers has developed a new sampling method and tested its effectiveness on human material from several archaeological sites in Hungary and abroad. The Hungarian archaeological material can be found in the collections of the Hungarian Natural History Museum, the Herman Ottó Museum, the Déri Museum and the Damjanich János Museum. The new method was initiated by Ron Pinhasi' research group at the Department of Evolutionary Anthropology, the University of Vienna and the methodological background was worked out, and the bone and tooth samples were analysed, and the Austrian team and David Reich' Laboratory at the Department of Genetics, Harvard Medical School. The anthropological background of the findings was provided by the Department of Anthropology at Eötvös Loránd University and Department of Anthropology at the Hungarian Natural History Museum and the Institute of Archaeology, ELKH-BTK (Tamás Hajdu, Tamás Szeniczey, Krisztián Kiss, Ildikó Pap, Kitti Köhler). The basic archaeological background data of the research (archaeological age, cultural classification, archaeological context of the finds) were provided by the joint work of the research staff of several Hungarian institutions (ELTE BTK Archaeological Institute: Alexandra Anders, Pál Raczky; Déri Museum: János Dani, Barbara Kolozsi, Emese Gyöngyvér Nagy; Herman Otto Museum: B. Hellebrandt Magdolna, Horváth Antónia; ELKH BTK Archaeology Institute: Király Ágnes; Damjanich János Museum: Kovács Péter; Ásatárs Kft.)

With increased media attention and political campaigns focusing on the gender pay gap, the fact that women -- on average -- are paid less than men, has become an important public discussion. While much of the focus has been on the corporate sector, a new study that looked at executive compensation at nonprofit organizations found that women earn 8.9% less than men with the gap becoming greater when there is room for salary negotiations.

The study co-authored by Curtis Hall, PhD, an associate professor in Drexel University's LeBow College of Business; Andrew R. Finley, assistant professor at the Robert Day School of Economics and Finance at Claremont McKenna College; and LeBow College of Business doctoral student Amanda R. Marino, analyzed data from IRS form 990 filings--where salaries of executuves in nonprofits are publicly disclosed--for four years across various industries.

The researchers first looked at whether or not a gap in pay does exist among executives in the nonprofit sector and then, the extent to which negotiation opportunities -- either real or perceived -- contribute to this difference.

"For various reasons we may not expect to observe a gender pay gap among the nonprofit sector even though recent research has found gaps in pay among for-profit executives," said Hall. "First, there is more female participation in the nonprofit workforce compared to the for-profit sector. Second, one may expect stakeholders, like donors or boards of directors to curtail gender pay gaps, but we didn't find this to be enough of a factor to prevent gender pay gaps."

To better understand the role of negotiation in contributing to the pay gap, the researchers examined settings with an expected variation in opportunities and willingness to negotiate. They looked at external employment options for the nonprofit executives, the organization's constraints in paying executives, the gender composition of its leadership and the pay variability within its executive ranks. Each of these factors uniquely influences the negotiation environment, according to the authors.

They found that executives' external employment options and competition lead to greater gender pay gaps with male executives more likely to capitalize on a broader external labor market or other opportunities to negotiate additional compensation.

However, in organizations with higher female board representation, and/or the presence of a female CEO, the pay gap is reduced. This may be because female leadership increases the willingness of female employees to negotiate, according to the authors.

"This study documents the contexts that influence negotiation on the gender pay gap, which is part of a larger societal issue," said Hall. "Employers should be cognizant of how the environment for negotiating compensation within their organizations can lead to gender-based pay disparities. Perhaps more importantly, business leaders and educators should think about ways to empower female workers to get more out of salary negotiations, which would hopefully help to close gender pay gaps in the future."

By discovering a potential new cellular mechanism for migraines, researchers may have also found a new way to treat chronic migraine.

Amynah Pradhan, associate professor of psychiatry at the University of Illinois Chicago, is the senior author of the study, whose goal was to identify a new mechanism of chronic migraine, and propose a cellular pathway for migraine therapies. The study, "Neuronal complexity is attenuated in preclinical models of migraine and restored by HDAC6 inhibition, is published in eLife.

Pradhan, whose research focus is on the neurobiology of pain and headache, explained that the dynamic process of routing and rerouting connections among nerve cells, called neural plasticity, is critical to both the causes and cures for disorders of the central nervous system such as depression, chronic pain, and addiction.

The structure of the cell is maintained by its cytoskeleton which is made up of the protein, tubulin. Tubulin is in a constant state of flux, waxing and waning to change the size and shape of the cell. This dynamic property of the cell allows the nervous system to change in response to its environment.

Tubulin is modified in the body through a chemical process called acetylation. When tubulin is acetylated it encourages flexible, stable cytoskeleton; while tubulin deacetylation - induced by histone deacetylase 6, or HDAC6, promotes cytoskeletal instability.

Studies in mice models show that decreased neuronal complexity may be a feature, or mechanism, of chronic migraine, Pradhan said. When HDAC6 is inhibited, tubulin acetylation and cytoskeletal flexibility is restored. Additionally, HDAC6 reversed the cellular correlates of migraine and relieved migraine-associated pain, according to the study.

"This work suggests that the chronic migraine state may be characterized by decreased neuronal complexity, and that restoration of this complexity could be a hallmark of anti-migraine treatments. This work also forms the basis for development of HDAC6 inhibitors as a novel therapeutic strategy for migraine," the researchers report.

Pradhan said this research reveals a way to possibly reset the brain toward its pre-chronic migraine state.

"Blocking HDAC6 would allow neurons to restore its flexibility so the brain would be more receptive to other types of treatment. In this model we are saying, maybe chronic migraine sufferers have decreased neuronal flexibility. If we can restore that complexity maybe we could get them out of that cycle," she said.

Once out of the cycle of decreased neuronal complexity, the brain may become more responsive to pain management therapies, Pradhan said. HDAC6 inhibitors are currently in development for cancer, and HDCA6 as a target has been identified for other types of pain.

"It opens up the possibility of something we should be looking at on a broader scale," she said. "Are these changes maybe a hallmark of all sorts of chronic pain states?"

Migraine is a common brain disorder that is estimated to affect 14% of the world population. Current U.S. cost estimates for migraine are as high as $40 billion annually. One particularly debilitating subset of migraine patients are those with chronic migraine, defined as having more than 15 headache days a month. Migraine therapies are often only partially effective or poorly tolerated, creating a need for more diverse drug therapies.

MINNEAPOLIS - Chronic kidney disease is when a person's kidneys progressively lose their ability to filter waste from the blood and eliminate fluids. Now a new study has found that people with reduced kidney function may have an increased risk of developing dementia. The study is published in the May 5, 2021, online issue of Neurology®, the medical journal of the American Academy of Neurology.

Chronic kidney disease affects approximately 15% of adults in the United States and it is more common as people age. However, since many people don't experience symptoms until later stages, it is estimated that 90% of people with chronic kidney disease don't know they have it.

"Even a mild reduction in kidney function has been linked to an increased risk of cardiovascular disease and infections, and there is growing evidence of a relationship between the kidneys and the brain," said study author Hong Xu, M.D., Ph.D., of Karolinska Institute in Stockholm, Sweden. "Just like with chronic kidney disease, the risk of dementia increases as people age. With no effective treatments to slow or prevent dementia, it is important to identify possible modifiable risk factors. If we could prevent or delay some cases of dementia by preventing or treating kidney disease, that could have important public health benefits. Our study shows that reduced kidney function is linked to the development of dementia, however it does not prove that it is a cause."

For the study, researchers used a database to identify nearly 330,000 people 65 years and older who received health care in the city of Stockholm and were followed for an average of five years. None of the participants had dementia or had undergone kidney transplants or dialysis at the start of the study. Over the course of the study 18,983 people, or 6% of participants, were diagnosed with dementia.

Creatinine is a waste product from muscles that is removed from the blood by the kidneys and released into the urine. Using blood tests of plasma creatinine, researchers estimated the glomerular filtration rate for each participant, a measure of how well the blood is filtered by the kidneys and that is commonly used to approximate kidney function. An estimated filtration rate of 90 milliliters (mL) per minute or higher is considered normal in most healthy people.

Using this measure, researchers then determined the rates of dementia in people with different levels of kidney function. They used person-years to calculate the difference. Person-years take into account both the number of people in the study and the amount of time each person spends in the study.

Researchers found as kidney function decreased, the rate of dementia increased. In people with a normal kidney filtration rate of 90 to 104 mL per minute, there were seven cases of dementia per 1,000 person-years. In people with severe kidney disease, or a filtration rate of less than 30 mL per minute, there were 30 cases of dementia per 1,000 person-years.

After adjusting for other factors that could affect dementia risk like smoking, alcohol use, hypertension and diabetes, researchers determined that people with filtration rates of 30 to 59 mL per minute, which indicates moderate chronic kidney disease, had a 71% higher risk of developing dementia compared to those with normal kidney function, and people with filtration rates of less than 30 mL per minute had a 162% higher risk.

Researchers also examined data on 205,622 participants who had multiple blood tests over one year. They used those tests to estimate the speed of kidney function decline. They found that a steeper decline in a person's filtration rates during this time frame was also associated with a higher risk of a dementia diagnosis later on.

According to researchers, 10% of the dementia cases could be attributed to a filtration rate of 60 mL per minute or less, which is a higher proportion of dementia cases than those attributed to other dementia risk factors like cardiovascular disease and diabetes.

"Our study identifies chronic kidney disease as a possible risk factor for dementia, however while it shows an association, it does not prove that it is a cause," said Xu. "More research is needed to determine the exact reasons for the association. Still, our findings raise awareness of the link between these two conditions and may help health professionals develop and implement strategies to screen for kidney disease and monitor kidney function in people at risk of dementia. Identifying and treating cases sooner may reduce the risk of dementia."

A limitation of the study was that dementia was identified by clinical diagnoses. Access to participants' medical records may have helped to identify more cases.

Virtual care provided through telephone or videoconference has been broadly implemented in recent months because of the COVID-19 pandemic. A new analysis of published studies has examined the accuracy and reliability of virtual compared with in-person cognitive assessments for diagnosing dementia or mild cognitive impairment.

The analysis, which is published in the Journal of the American Geriatrics Society, included 121 studies. Three studies comparing videoconference with in-person cognitive assessments demonstrated good reliability and accuracy of virtual cognitive assessments in diagnosing dementia. Investigators did not identify any studies comparing telephone with in-person cognitive assessments.

The analysis also allowed the researchers to identify virtual cognitive test cut-offs suggestive of dementia or mild cognitive impairment, as well as barriers to implementing cognitive assessments for older adults.

"Our results highlight serious knowledge gaps and challenges associated with implementing virtual care for older adults--especially when you consider that the majority of older adults continue to access virtual care via the telephone," said lead author Jennifer A. Watt, MD, PhD, of St. Michael's Hospital-Unity Health Toronto, in Canada.

A new study published in the British Journal of Educational Technology has identified the different needs of students across primary, middle, and high school related to online learning during the COVID-19 pandemic.

For the study, investigators surveyed 1,170,769 Chinese students from the Guangdong Province of China.

Based on their findings, the researchers recommend that educational authorities and schools provide sufficient technical support to help students overcome potential internet and technical problems, and customize the delivery of online learning tools for students in different school years.

"Utilizing data from a large sample, we identify that student requirements of online learning are not homogeneous. For young children, there is a need for guidance from teachers and parents. In contrast, older students require opportunities to collaborate," said lead author Lixiang Yan, of the Centre for Learning Analytics at Monash University, in Australia. "Our study also showed an overwhelming use of smartphones over other devices by all age groups. This finding has direct implications for the design of online courses in K12 education; however, this can potentially pose a significant limitation for an effective learning experience."

The population growth of an endangered butterfly species is greatest in habitats with microclimatic variability, demonstrates a study carried out collaboratively by the Faculty of Biological and Environmental Sciences and the Helsinki Institute of Life Science of the University of Helsinki as well as the Finnish Environment Institute.

Insects are often very restricted in their capacity for movement. In many species, specific stages of life are spent entirely immobile, making them dependent on the temperature and moisture conditions of their immediate surroundings. In the Åland Islands on the southwest coast of Finland, Glanville fritillary butterflies (Melitaea cinxia) spend roughly 10 months of the year in the larval stage. In the middle of summer, the newly hatched larvae eat, as a group, the host plant, on whose leaf the female happened to lay the eggs. Prior research has shown that plants can wither entirely in dry summers, with prolonged dry periods sealing the fate of butterfly larvae. In such cases, only those larvae survive whose eggs have been laid on a plant growing in an exceptionally moist spot.

"We investigated how varying microclimates affect larval growth and survival in the spring after the overwintering. We found that warm and sunny days in March woke up the larvae and made them look for food. However, very little food was to be found, since the few warm days in early spring were followed by a cool April, with the growing season of the larval host plants only beginning in earnest in May," says doctoral researcher Susu Rytteri from the University of Helsinki's Research Centre for Ecological Change. She defended her thesis at the end March 2021.

It was observed that, in sunny and warm microclimates, larvae grew faster but also perished in large numbers because of lack of food. In cooler and shadier microclimates, larval growth was slow, a boost to the sufficiency of food: food plants had the time to grow in sync with the nutritional requirements of the larvae. Comprehensive survey data from the Åland Islands also demonstrated that Glanville fritillary populations grew the most in meadows where their larvae inhabited varying microclimates.

"The growth of butterfly populations increased when larval groups were located in particularly warm spots on sunny southward slopes. At the same time, the larvae also benefited from cooler and shaded microclimates. Due to the unpredictability and variability of weather conditions, the optimal egg-laying strategy for insects would appear to be laying eggs in varying microclimates which have the capacity to protect their immobile offspring from unfavourable conditions. The problem is that habitats have declined in number and become increasingly uniform. Consequently, varying microclimates are not necessarily on offer," Rytteri says.

More microclimatic variability in yards and gardens

Promoting microclimatic variability in your backyard helps insects and other animals. The sunniest spot in the yard can be turned into an even warmer place for sunbathing by, for example, constructing a section of stone wall that stores heat and offers protective crevices for small creatures. An oasis in the shade can be built in the coolest location in the yard by planting lush plants that thrive away from the sun and by adding a water element that is not only pleasing to the human eye but also serves as a watering place for animals during dry spells.

"Butterflies benefit from diverse plants, and in butterfly gardens, the goal should be floral splendour stretching from early spring long into the autumn. Many garden plants are good melliferous plants, that is, plants rich in pollen and nectar, but wild meadow plants shouldn't be overlooked either. Trees, bushes, rocks and knolls form variable microclimates and offer protection from unfavourable weather conditions," Rytteri points out.

Joyce WG, Rollot Y, Evers SW, Lyson TR, Rahantarisoa LJ, Krause DW. 2021. A new pelomedusoid turtle, Sahonachelys mailakavava, from the Late Cretaceous of Madagascar provides evidence for convergent evolution of specialized suction feeding among pleurodires. Royal Society Open Science 8:210098. https://doi.org/10.1098/rsos.210098

First author: Prof. Dr. Walter Joyce (walter.joyce@unifr.ch), Professor of Paleontology, University of Fribourg, Switzerland

Co-authors:

- Yann Rollot (yann.rollot@unifr.ch), PhD student, University of Fribourg, Switzerland

- Serjsocha Evers (serjoscha.evers@unifr.ch; preferred: serjoscha.evers@googlemail.com), Postdoctoral Researcher, University of Fribourg, Switzerland

- Tyler Lyson (Tyler.Lyson@dmns.org), Associate Curator of Vertebrate Paleontology, Denver Museum of Nature and Science, USA

- Lydia Rahantarisoa (ralyhanta@yahoo.fr), Professor of Geology, Université d'Antananarivo, Madagascar

Senior author: David Krause (David.Krause@dmns.org), Senior Curator of Vertebrate Paleontology, Denver Museum of Nature & Science, USA

Figure details

Fig. 1 Life reconstruction of Sahonachelys mailakavava, preying upon tadpoles of the giant Madagascan frog Beelzebufo ampinga using specialized suction feeding. Artwork by Andrey Atuchin.

Fig. 2 Fossil of Sahonachelys mailakavava, showing the preserved skull parts.

Fig. 3 Fossil of Sahonachelys mailakavava, showing the preserved shell.

Content and importance

We here describe a new species of pelomedusoid turtle from a geological formation in Madagascar otherwise known for its exquisitely preserved fossil birds, dinosaurs, crocodilians, and mammals. The new turtle possesses an unusually flattened skull combined with a particularly gracile lower jaw and enlarged tongue bones (hyoids), which not only gave it a frog-like appearance, but also suggests that it was adapted to a specialized feeding mode called suction-feeding.

Suction feeders open their mouths rapidly to suck in prey items under water, which is in contrast to other subaquatic feeding modes in which animals shoot their heads forward to reach for prey. The new turtle has several modifications in its head skeleton that show that it was well suited for suction feeding: its skull is low but wide, and the jaws are strongly bowed and angled forward, which creates a strongly rounded mouth opening that is physically beneficial for creating large suction forces. The tongue bones are strongly developed, and this hints at large muscles that pulled the tongue skeleton backwards and opened the esophagus during the strike at prey - again creating more suction. As in all modern turtles, the new species lacks teeth, but in addition the surfaces at the upper and lower jaws that face toward each other are poorly developed, showing that this turtle did not use its jaws to process food, but instead swallowed prey whole, which is typical for suction feeders. We hypothesize that the turtle fed on small-bodied living prey, such as insect larvae, fish fry, and tadpoles using quick strikes. We, therefore, name the new species Sahonachelys mailakavava, which means "quick-mouthed frog turtle" using Malagasy and Greek words. Special about the turtle is also its preservation: it is known from a nearly complete skeleton, despite its small body size, barely more than a foot long.

Turtle fossils often come either as shells or skulls that have been separated from one another; for many extinct turtles, we only either one or the other, but not both. Having a complete skeleton helps us to understand the whole animal, and also makes it possible to compare it to other turtle fossils, regardless of how these are preserved. Based on such comparisons, we constructed a family tree of turtles that shows that Sahonachelys mailakvava was an early relative of podocnemidid turtles, which today are native to Madagascar and South America, but which were more widespread in the past.

The palaeontological fauna of Madagascar is known for animals that are very specialized, which is in part due to its long isolation from surrounding continents. Our turtle shows that the Madagascan fauna was already unique in the Late Cretaceous: Sahonachelys mailakavava is the only representative of its group to have evolved suction-feeding, which is otherwise only known in distant relatives, so-called snake-necked turtles.

Quotes by the authors:

"This is the best-preserved turtle of the entire Late Cretaceous of the southern continents and as such very significant in terms of reconstructing its way of life and relationships with other turtles" (Prof. Walter Joyce, first author of study)

"As palaeontologists, we try to understand the biology and evolution of past life. Fossils like this give a wealth of information that is not always present. The identification of suction feeding in a new turtle lineage is exciting and was unexpected. It shows how animals evolve similar traits for similar functions, even if they are only distantly related." (Serjoscha Evers, co-author of study)

"Sahonachelys is a stunning example of evolution in isolation. It represents a lineage that evolved on Madagascar for over 20 million years and joins a litany of other bizarre Late Cretaceous vertebrate animals that we've found on the island. This specimen is, by far, the best turtle fossil we discovered during the 28 years of conducting field research there." (David Krause, co-author of study)

Journal

Royal Society Open Science

DOI

10.1098/rsos.210098

Measures to contain the Corona pandemic are the subject of politically charged debate and tend to polarize segments of the population. Those who support the measures motivate their acquaintances to follow the rules, while those who oppose them call for resistance in social media. But how exactly do politicization and social mobilization affect the incidence of infection? Researchers at the Max Planck Institute for Human Development have examined this question using the USA as an example. Their findings were published in Applied Network Science.

Limit crowds, keep a safe distance, and wear masks. Such non-pharmaceutical interventions, which should be implemented by everyone if possible in order to contain the incidence of infection, have played a central role since the beginning of the Corona pandemic. These measures have been disseminated via not only traditional media such as newspapers, radio, and television but also social media to a large extent. We can see that the appeals, recommendations, and regulations of governments are not only met with approval and understanding but also stimulate politically charged discussions, polarization, conspiracy narratives, and mobilization against the measures - often mixed with personal opinions.

But what does the rejection of Corona measures depend on? And is there a connection between the politicization of Corona topics in social networks and the development of the infection figures? Researchers at the Max Planck Institute for Human Development have investigated this using a mobilization model based on the example of Facebook in the USA. The subject of the study was a hypothetical political campaign in which the Democratic Party recommends non-pharmaceutical measures to combat the spread of Corona virus.

The results of the model calculations show that the hypothetical Democratic campaign would have spread to Democratic states three times faster than to Republican states. No matter in which direction, this political polarization makes it difficult to reach most segments of the population equally. "Accordingly, the acceptance and further dissemination of measures depends on whether the sender and receiver are politically like-minded," says Inho Hong, lead author of the study and a research grant holder in the Center for Humans and Machines at the Max Planck Institute for Human Development.

The researchers then examined the relationship between social mobilization and the actual spread of COVID-19 cases in the USA. They found that, on one hand, mobilization can have a positive effect on pandemic response when large numbers of people join together online to support the regulations by disseminating them quickly and early. On the other hand, there are indications that the political charge and resulting actions may have exacerbated the incidence of infection in some geographies. For example, infection rates spiked starting in mid-April 2020 after Republicans demonstrated against the first lockdown and did not consistently comply with the specified hygiene rules. This means that political regulations such as lockdowns can have the opposite effect after they are reinterpreted by politically polarized opponents - and even exacerbate the situation.

The researchers used a mobilization model to simulate the processes of social mobilization. The data for this came from two sources: The "Facebook Social Connectedness Index", a measure for calculating social connections between people from different regions, and demographic information and data sets from election protocols of the New York Times. Based on this data, the researchers calculated how the Democratic campaign would have spread via Facebook and whether it would have led to political actions such as demonstrations.

In previous studies, researchers have used this mobilization model to examine how political actions have formed and spread on social networks in the USA. "The model has allowed us to show a link between the social divide in the USA, the spread of information via Facebook, and the evolution of the incidence of infection," says Alex Rutherford, senior research scientist and principal investigator with the Center for Humans and Machines at the Max Planck Institute for Human Development and co-author of the study.

The study results show that a political charging of the measures to combat the pandemic can have a counterproductive effect and even fuel the incidence of infection. "On social media, the mask was quickly re-interpreted as a political statement and used to polarize the population. Governments should therefore consider to whom and through which channels they disseminate information and whether they want to target mobilization," says Manuel Cebrian, Leader of the Digital Mobilization Research Group at the Center for Humans and Machines at the Max Planck Institute for Human Development and co-author of the study.

The focus of the study was on political attitudes of US citizens. Other possibly decisive social factors such as occupation, income, gender, and origin would have to be investigated in further studies. These could provide information for planning the communication of future measures - for example, government vaccination strategies.

Honeybees have a complex communication system. Between buzzes and body movements, they can direct hive mates to food sources, signal danger, and prepare for swarming - all indicators of colony health. And now, researchers are listening in.

Scientists based in Germany - with collaborators in China and Norway - have developed a way to monitor the electrostatic signals that bees give off. Basically, their wax-covered bodies charge up with electrostatic energy due to friction when flying, similar to how rubbing your hair can make it stand on end. That energy then gets emitted during communications.

"We were thrilled by the potential of directly accessing the social communication of bees with our method," says Dr. Randolf Menzel, of the Free University of Berlin. "For the first time we can ask the bees themselves whether their colony is in a healthy condition or whether they suffer from unfavorable environmental conditions including those caused by humans."

The paper, recently published in the open access journal Frontiers in Behavioral Neuroscience, likens honeybee colonies to a canary in a coal mine. Bees are usually among the first species to be affected by pollutants such as insecticides, and weakened communications can signal their damaging effects. Such evidence may point to potential harm to other wildlife and ecosystems in a way that is quicker and cheaper than other methods.

Menzel and his colleagues worked with 30 beekeepers across Germany over a period of five years. They placed sensors and a central recording device inside and outside a specially designed hive, and monitored the honeybees' electrostatic field (ESF) data.

They were particularly interested in what is known as the "waggle dance," a sophisticated messaging system in which honeybees walk in a figure-eight pattern, then "waggle" back and forth through the stretched part of the intersection. This bee ballet communicates flight directions and distance. "Other bees follow the dancing bee, read the message of the dancer, and apply the information about distance and direction to an attractive food source in their outbound flights," says Menzel.

The primary purpose of their research study was to measure the feasibility of their recording system, which did indeed work, although Menzel notes that scaling up their system would be challenging, and "to get meaningful knowledge about the impact of pesticides and health conditions of bees in a larger area, we will have to use many devices across that area."

Still, the researchers learned more about hive communication, and found what Menzel described as "unexpected phenomena." For example, they found that bees perform waggle dances at night as well as during the day, and that insecticides used for treatment against pest mites had a negative impact on honeybees' communication. They also found that ESF signals were emitted in preparation of swarming, and that their strength didn't depend on environmental conditions such as humidity and UV radiation.

Menzel says that their system collected a large amount of data, and that they need further studies to improve and finetune interpretation. "So far we have only begun to apply machine learning algorithms to separate and quantify the electrostatic field signals." In the future though, it's possible that eavesdropping on bees may provide rich and important information beyond the local pollen hotspot. Their communications could be crucial in understanding - and protecting - whole ecosystems.