Culture

Oysters' exposure to plastics is concerning, particularly because these materials can accumulate and release metals which are then absorbed by the molluscs. According to a recent study published in the journal Chemosphere, the combined presence of nanoplastics and arsenic affects the biological functions of oysters. This study was conducted by the Institut national de la recherche scientifique (INRS) in Québec City and the French National Centre for Scientific Research (CNRS) at the University of Bordeaux in France.

The international research team chose to study arsenic, since it is one of the most common metals absorbed by the plastic debris collected from the beaches of Guadeloupe. "Oysters easily accumulate metals from the environment into their tissues. We therefore wanted to test whether the combined exposure to nanoplastics and arsenic would increase the bioaccumulation of this contaminant," reported Marc Lebordais, the Master's student in charge of the research.

The scientists proved that the bioaccumulation of arsenic does not increase when nanoplastics are also present. However, it remained higher in the gills of the Canadian Crassostrea virginica oyster than in the Isognomon alatus oyster, found in Guadeloupe. These results are the first to highlight the diverging sensitivity of different species.

Gene deregulation

In addition to bioaccumulation, the team also observed an overexpression of genes responsible for cell death and the number of mitochondria--a cell's energy centres--in C. virginica. In I. alatus, the expression of these same genes was less significant.

"Evaluating the expression of genes involved in important functions, such as cell death and detoxification, gives us information on the toxicity of nanoplastics and arsenic on a cellular level," explained the young researcher, who is co-directed by Professors Valérie Langlois of INRS and Magalie Baudrimont of the University of Bordeaux.

The food chain

The next step, after characterizing the presence of nanoplastics and arsenic in oysters, would be to study how these contaminants are transferred through the food chain.

"Analytical tools are currently being developed to quantify the presence of nanoplastics in biological tissues," said Marc Lebordais. "Understanding the amount of nanoplastics in farmed oysters currently boils down to a technical issue." ?

Research shows that poor sleep health may disproportionately affect children of color from families of low socioeconomic status and place them at risk for behavior problems and lower academic performance. However, few sleep studies utilize standard measures of both classroom behavior and academic achievement.

A new longitudinal study examined the relation between sleep, classroom behavior, and academic achievement scores among primarily Black children growing up in historically disinvested neighborhoods. Disinvested refers to neighborhoods in which public and private funding, city services, or other necessary resources have been denied or withheld, and which are often segregated along racial and economic lines as a result. The findings showed that sleep is related to observed classroom behavior and may predict future academic achievement.

The findings were published in a Child Development article, written by researchers at the NYU Grossman School of Medicine, Harvard Medical School, and University of Texas at Austin.

According to the study, higher teacher-reported child sleepiness was associated with lower observed adaptive behaviors (defined as active engagement in learning in the classroom), and higher classroom behavior problems in first grade. Higher teacher-reported child sleepiness also predicted lower academic achievement as assessed one year later, in second grade. Parent-reported bedtime resistance and disordered breathing also predicted lower achievement in second grade.

"Our study, the first to examine the ways in which sleep is related to observed engagement in learning and academic test scores among primarily Black children growing up in disinvested neighborhoods, highlights the importance of educating both parents and teachers about fostering positive sleep habits in young children for their school success," said Alexandra Ursache, assistant professor in the department of population health at NYU Grossman School of Medicine. "The study indicates that encouraging teachers to share their observations of children's sleepiness with parents, in a collaborative and culturally-affirming manner could help make them aware of its interference with learning."

The study included 572 predominantly Black first grade girls and boys with over half coming from immigrant families. The children came from 10 schools located in historically disinvested neighborhoods in New York City. Children in first and second grade (approximately ages 6 and 7), were assessed on:

Sleep health and sleep disorder symptoms: Parents used a questionnaire to report on their children's bedtime resistance, sleep duration, disordered breathing, daytime sleepiness, and sleep onset delay. Teachers reported on their students' daytime sleepiness.

Classroom behavior (adaptive and problem behaviors): Observers from the research team used a coding system to assess students' adaptive behaviors (non-verbal actively engaged learning such as listening, nodding, sitting up, working on an assigned task) and problem behaviors (behavioral or emotional problems).

Academic achievement: A standardized academic achievement assessment was administered by trained research assistants to assess reading, math and writing ability in second grade.

"Sleep is an essential component of healthy development for children, and children of color are at elevated risk for poor sleep health and undetected sleep disorders," said Alicia Chung, assistant professor in the department of population health at NYU Grossman School of Medicine. "This can set the stage for sleepiness in school, increased problem behavior, decreased engagement in learning activities and lower academic achievement."

"The findings raise the possibility that developing a sleep health curriculum may help engage teachers and parents to promote sleep health," said Rebecca Robbins, instructor in medicine at Harvard Medical School.

The authors acknowledge that the measures of sleep used in this study were reported by parents and teachers rather than objective, standardized assessments (for example, collected through activity monitors). The authors also recognize that the measures provided by teachers and parents may include inherent bias involving Black children or African American children being incorrectly rated as sleepy. Although the authors controlled for several important covariates and examined longitudinal relations with academic achievement, they cannot make strong causal claims about the relations between sleep health and classroom behavior or achievement without a research design that intentionally manipulates sleep behavior, for example by randomly selecting some families to participate in an intervention to promote sleep health. This work may also not be generalized to Latinx children or other populations of children of color.

Highlights

Among patients receiving dialysis in the Southeastern United States, those at for-profit dialysis facilities were less likely to be referred for kidney transplantation than those at non-profit facilities.

Rates of starting medical evaluations soon after referral and placing patients on a waitlist after evaluations were similar between the groups.

Washington, DC (May 26, 2021) -- New research indicates that patients with kidney failure who receive care at for-profit dialysis facilities are less likely to be referred for kidney transplants that those receiving care at non-profit facilities. The findings will appear in an upcoming issue of CJASN.

Kidney transplantation is the optimal therapy for most patients with kidney failure. Many patients first initiate dialysis and are referred for a transplant by kidney specialists through dialysis facilities. Previous studies have reported that patients treated at for-profit dialysis facilities are less likely than those treated at non-profit facilities to be placed on a transplant waitlist and to receive a transplant. Little information is available concerning earlier steps in the process, however--namely, referrals and medical evaluations for transplantation.

To investigate, a team led by Rachel E. Patzer, PhD and Laura J. McPherson, MPH (Emory University) examined referral and evaluation data from all 9 transplant centers in the Southeastern United States (Georgia, North Carolina, and South Carolina), as well as information from the United States Renal Data System.

The analysis included 33,651 patients with kidney failure who initiated dialysis in the Southeast from 2012 to 2016. Eighty-five percent of patients received dialysis treatments at for-profit facilities, and 15% were treated at non-profit facilities. A total of 44% of patients were referred for transplant during the 4-year study period. After adjustments, patients at for-profit facilities were 16% less likely to receive a referral than patients at non-profit facilities. Rates of starting medical evaluations within 6 months of referral and placing patients on a waitlist within 6 months of evaluations did not meaningfully differ between the groups.

"Our study offers insight into the practice patterns related to referral for transplantation, start of the transplant evaluation at the transplant center, and placement on the national deceased donor waiting list, but our study does not have detailed information about the mechanisms and reasons for these differences in referral between for profit and non-profit facilities," said Dr. Patzer. "The reasons for these differences in referral could be due to differences in patients' health status that are not measured in our dataset, or they could be due to other unmeasured factors such as limited time to educate or refer patients for transplant, or unconscious bias. Future research is still needed to better understand these mechanisms, such as through focus groups and interviews with patients and care provider team members."

An accompanying editorial notes that "the early steps in transplant access remain frustratingly opaque, indicating the ongoing need to address long-standing disparities and ensure equity in treatment options for patients with kidney failure."

Jodi Karnell and colleagues have developed a monoclonal antibody, VIB7734, that reduces symptom severity in people with cutaneous lupus by targeting and depleting plasmacytoid dendritic cells (pDC) in blood and skin. In two phase I clinical trials involving a total of 67 people with autoimmune diseases such as lupus, treatment with VIB7734 was as safe as a placebo and significantly reduced pDC frequencies, the researchers found. The antibody also reduced the activity of a group of key immune proteins called type 1 interferons in skin. Both pDCs and type 1 interferons are suspected to play a role in autoimmune conditions including lupus, so the new antibody may be an effective treatment option against autoimmunity if these initial results are supported in further clinical trials. VIB7734 targets a molecule on the surface of pDCs to deplete them, often halving the number of these cells after just one dose in non-human primates and patients with autoimmune diseases. In patients with cutaneous lupus treated with a high dose (150 milligrams) of VIB7734, 87.5% had clinically meaningful reductions in their symptoms one month after treatment, compared with 37.5% for those treated with a 50-milligram dose and 28.6% for those treated with a placebo. Karnell et al. also note that VIB7734 seems to work best in people with high concentrations of type 1 interferons circulating in the blood, suggesting that baseline type 1 interferon concentrations could predict patient responses.

UNIVERSITY PARK, Pa. -- One of the most important and widespread reef-building corals, known as cauliflower coral, exhibits strong partnerships with certain species of symbiotic algae, and these relationships have persisted through periods of intense climate fluctuations over the last 1.5 million years, according to a new study led by researchers at Penn State. The findings suggest that these corals and their symbiotic algae may have the capacity to adjust to modern-day increases in ocean warming, at least over the coming decades.

Cauliflower corals -- which are in the genus Pocillopora -- are branching corals that provide critical habitat for one-quarter of the world's fish and many kinds of invertebrates, such as lobsters, sea urchins and giant clams. They are common throughout the Indo-Pacific -- the region extending from eastern Africa, north to India and Southeast Asia, across Australia and encompassing Hawaii -- and are capable of long-range dispersal and rapid growth, making them among the first species to repopulate reefs damaged by typhoons and events of mass coral bleaching and mortality.

"We found that Pocillopora has maintained a close relationship with certain species of algae in the genus Cladocopium over repeated oscillations in Earth's climate," said Todd LaJeunesse, professor of biology, Penn State. "Our findings reinforce how stable and resilient these relationships are over deep time."

LaJeunesse explained that corals comprise hundreds to hundreds of thousands of individual animals, called polyps. Tiny, single-celled algae, known as dinoflagellates, live inside these polyps' tissues, giving the corals their color and providing the animals with up to 90% of their energy needs through the products of photosynthesis. These dinoflagellates significantly influence the capacity of corals to deal with environmental stressors.

For two decades, LaJeunesse and his colleagues have been collecting coral samples from around the world, using molecular-genetic techniques to identify the coral and algal species, documenting the specificity of the partnerships (some species of algae are highly specific to certain species of coral, whereas others are generalists and can associate with many different types of coral) and determining how these partnerships have changed through evolutionary history.

"Important biological discoveries are more likely when working with accurate species resolution -- in this case, for both coral and dinoflagellate," said LaJeunesse. "Research on the biology of photosynthetic corals has been hampered by a lack of good taxonomic resolution. Our work on resolving these species is highly detailed and currently among the most sophisticated."

The team used a combination of genetic, ecological and morphological -- the outward appearance of an organism -- techniques to examine Cladocopium that associate with Pocillopora. Specifically, they relied on a variety of genetic markers -- or DNA sequences with known locations on chromosomes -- to determine the genetic identities of the species. They also used a microscope to visualize and image the Cladocopium cells. The findings published on May 20 in the ISME Journal, the official journal of the International Society for Microbial Ecology.

"With this research, we now know that Cladocopium, the most common genus of coral symbionts, comprises hundreds of species," said Kira Turnham, graduate student in biology, Penn State. "We were able to identify and describe two species, which we named Cladocopium latusorum and Cladocopium pacificum, and with this resolution, were able to deduce the age of their partnerships and unique importance to specific host corals."

Next, the team investigated whether Cladocopium from geographically dispersed populations of Pocillopora were reproductively isolated or displayed connectivity. They found that populations of both species, like their Pocillopora hosts, are genetically well-connected across the tropical and sub-tropical Pacific Ocean, indicating a capacity for long-range dispersal.

For instance, Turnham said, "Cladocopium latusorum spans the Indian and Pacific Oceans -- from the eastern shores of Tanzania to the Coral Triangle, Great Barrier Reef in Australia and Panama. This connectivity between populations in different locations may contribute to the resiliency of these species to endangerment or extinction threats."

To determine how old the partnerships are, the researchers used a "molecular clock" -- an analysis that assesses DNA sequence divergence over time -- to estimate when the two Cladocopium species diverged from their common ancestor. They found that the species arose during the late Pliocene to early Pleistocene epochs, at a time when their coral host was also forming new species.

"There has been considerable talk about corals' ability to shuffle their dinoflagellate species to improve their ability to withstand global warming," said LaJeunesse. "While some of this may be true, most corals have a very limited assortment of species with which they are able to associate. We have shown that with this limited number of compatible symbionts, Pocillopora have been able to deal with major changes in climate every 100,000 years for the past 1-to-2 million years."

Turnham noted that despite their persistence through time, the strict nature of the relationship between Pocillopora and Cladocopium may limit their ability to evolve in response to increased warming compared to corals that can associate with more thermally tolerant dinoflagellates.

"Ultimately," she said, "the broad geographic distributions and geological age of these and other coral-algal combinations must be considered in forecasting their response to ocean warming, and guide decisions when planning for their conservation."

To help patients manage their mental wellness between appointments, researchers at Texas A&M University have developed a smart device-based electronic platform that can continuously monitor the state of hyperarousal, one of the signs of psychiatric distress. They said this advanced technology could read facial cues, analyze voice patterns and integrate readings from built-in vital signs sensors on smartwatches to determine if a patient is under stress.

Furthermore, the researchers noted that the technology could provide feedback and alert care teams if there is an abrupt deterioration in the patient's mental health.

"Mental health can change very rapidly, and a lot of these changes remain hidden from providers or counselors," said Dr. Farzan Sasangohar, assistant professor in the Wm Michael Barnes '64 Department of Industrial and Systems Engineering. "Our technology will give providers and counselors continuous access to patient variables and patient status, and I think it's going to have a lifesaving implication because they can reach out to patients when they need it. Plus, it will empower patients to manage their mental health better."

The researchers' integrated electronic monitoring and feedback platform is described in the Journal of Psychiatric Practice.

Unlike some physical illnesses that can usually be treated with a few doctor visits, people with mental health needs can require an extended period of care. Between visits to a health care provider, information on a patient's mental health status has been lacking. Hence, unforeseen deterioration in mental health has a limited chance of being addressed. For example, a patient with anxiety disorder may experience a stressful life event, triggering extreme irritability and restlessness, which may need immediate medical attention. But this patient may be between appointments. On the other hand, health care professionals have no way to know about their patients' ongoing struggle with mental health, which can prevent them from providing the appropriate care.

Hence, patient-reported outcomes between visits are critical for designing effective health care interventions for mental health so that there is continued improvement in the patient's wellbeing. To fill in this gap, Sasangohar and his team worked with clinicians and researchers in the Department of Psychiatry at Houston Methodist Hospital to develop a smart electronic platform to help assess a patient's mental wellbeing.

"The hospital has the largest inpatient psychiatry clinic in the Houston area," said Sasangohar. "With this collaboration, we could include thousands of patients that had given consent for psychiatric monitoring."

Sasangohar's collaborators at Houston Methodist Hospital were already using an off-the-shelf patient navigation tool called CareSense. This software can be used to send reminders and monitoring questions to patients to better assess their wellbeing. For instance, individuals at risk for self-harm can be prompted to take questionnaires for major depressive disorder periodically.

Rather than solely relying on the patients' subjective assessment of their mental health, Sasangohar and his team also developed a whole suite of software for automatized hyperarousal analysis that can be easily installed on smartphones and smartwatches. These programs gather input from face and voice recognition applications and sensors already built in smartwatches, such as heart rate sensors and pedometers. The data from all of these sources then train machine-learning algorithms to recognize patterns that are aligned with the normal state of arousal. Once trained, the algorithms can continuously look at readings coming from the sensors and recognition applications to determine if the individual is in an elevated arousal state.

"The key here is triangulation," said Sasangohar. "Each of these methods on their own, say facial sentiment analysis, show promise to detect the mental state, albeit with limitations. But when you combine that information with the voice sentiment analysis, as well as physiological indicators of distress, the diagnosis and inference become much more powerful and clearer."

Sasangohar noted that both the subjective evaluation of mental state and the objective evaluation from the machine-learning algorithms are integrated to make a final assessment of the state of arousal for a given individual.

While their technology's prototype is ready, the researchers said they still need to improve the battery life of smartphones carrying their software since the algorithms guzzle a lot of power. Further, they noted that they have to address usability issues, that is, any issues that prohibit patients from using their technology, such as difficulty in navigating their application.

"Because of the stigmatization that surrounds mental illness, we wanted to build a mental health monitoring device that was very discreet," said Sasangohar. "So, we chose off-the-shelf products, like smartphones, and then build sophisticated applications that operate within these devices to make monitoring mental health discreet."

Up to half of patients with head and neck squamous cell carcinoma will experience tumor recurrence or new tumors--tumors that often spread and are difficult to treat.

A team of scientists led by the University of Michigan School of Dentistry identified a mechanism by which head and neck cancer cells subvert adjacent normal tissue, allowing small clusters of cancer cells to burrow beneath the healthy tissue.

The team decided to look at this particular mechanism in head and neck cancer because a specific gene, DMBT1, appeared on a screen of genes that are silenced during oral cancer, said principal investigator Nisha D'Silva, the Donald A. Kerr Endowed Collegiate Professor of Oral Pathology.

Researchers from the D'Silva lab found that when DMBT1 was suppressed in head and neck cancer cells, it promoted aggressive invasion and metastasis in laboratory studies
and was associated with metastasis in patients.

They also found that two proteins secreted by head and neck cancer cells suppress DMBT1 in nearby ?healthy tissue, subverting it to promote invasion of a small amount of cancer cells, which burrow under healthy tissue.

Researchers looked at this mechanism in mice, chick embryos and cultures of human cancer cells. ??In the chick embryos, none of the tumors that overexpressed DMBT1 metastasized, whereas most of the control tumors that had low DMBT1 metastasized, D'Silva said.

"The importance of this paper is that loss of DMBT1 in cancer cells and adjacent normal tissue benefits cancer cells, allowing them to travel in tiny groups away from the main tumor," she said. "That is why cancer cells enlist the help of the adjacent tissue. Finding ways to interrupt this communication and enhance DMBT1 expression could help improve outcome."

The findings, published in the Journal of Experimental Medicine, could open possibilities for new therapeutics that target proteins in cancer cells that regulate DMBT1 and could have implications for other cancers in which DMBT1 expression is altered, D'Silva said.

"We are familiar with cancer cells enlisting the help of other cell types to grow and spread," she said. "Our research demonstrated that cancer cells also communicate with healthy cells of their own cell type to facilitate spread."

Head and neck cancer is the sixth most common cancer in the world, with 600,000 new cases annually.

ITHACA, N.Y. - Approximately one-third of all U.S. counties do not exempt grocery foods from the general sales tax, which means the lowest-income families living in those areas are most susceptible to food insecurity. New research from Cornell University finds that even a slight grocery tax-rate increase could be problematic for many.

"An increase of 1% to 4% may sound small, but after several trips to the grocery store, the extra costs can create serious burdens for the lowest-income families," said co-author Harry Kaiser, professor of applied economics and management in the Charles H. Dyson School of Applied Economics and Management. "We found that even the slightest increase in tax rate correlated to an increased likelihood of food insecurity. Grocery taxes that rose by just one percentage point led to a higher risk of hunger in households."

The study focused on sales taxes on foods at retail outlets such as grocery and convenience stores. Kaiser and his co-authors found that, across 14 states, the average grocery tax is just over 4%.

In 2020, grocery food tax policy varied at both state and county levels. A total of 17 states impose grocery taxes, and several states are debating whether to remove or impose taxes. Kaiser's group looked at data from low-income households in the 48 contiguous states plus Washington, D.C., and excluded households with annual income above $30,000.

This threshold was based on the federal poverty level, a measure that accounts for household income relative to household size. For example, in 2017 the poverty level for a single-person household was $12,060; for a two-person household, it was $16,240.

In Alabama, for example, where the grocery tax rate is as high as 9%, the average annual expense in grocery taxes is $630. For households living at or near the poverty level, this tax expense represents a sizeable portion of their household income.

Kaiser's team predicts that the average food insecurity for households with income less than $30,000 will decrease by 3.2% due to the tax removal.

"We hope that by sharing our current data and findings on grocery taxes as it relates to food insecurity," Kaiser said, "policymakers will take a much closer look at the tax burden in certain areas which are hit hardest."

It's well known that reptiles depend on temperature cues while in the egg to determine a hatchling's sex. Now, researchers writing in the journal Trends in Ecology & Evolution on May 26 say that embryos of many different animal species also rely on acoustic signals in important ways. They call this phenomenon "acoustic developmental programming."

"Acoustic developmental programming occurs when a sound informs embryos about the environment they'll encounter postnatally and changes their development to better suit this environment," said Mylene Mariette (@MyleneMariette) of Deakin University in Australia.

Because this is a newly discovered phenomenon, the evidence is just beginning to accumulate. And, yet, it seems to be rather widespread among animals.

"We have found evidence of this happening in birds, where parental calls can warn embryos about heatwaves or predators," Mariette says. "Before that, there was also evidence that cricket nymphs use male songs to predict the level of competition for mates. However, what is most striking from the evidence we've gathered is how common it is for embryos across species to rely on sound information.

"For example," she adds, "across all animal groups that lay eggs, such as insects, frogs, reptiles and birds, embryos use sound or vibration to know when the best time is to hatch. This suggests that acoustic developmental programming is likely to happen in many animal species and for a whole range of conditions. But, until recently, we did not know it was happening."

Mariette got interested in acoustic developmental programming while studying how zebra finch parents communicate with each other through calls to coordinate parental care duties. "I noticed that when a parent was alone incubating, it would sometimes produce a strange high-pitched call," she says.

She wondered if those calls had further implications for the developing embryos. To find out, she captured many audio recordings in nests and played them to eggs incubated artificially in the lab. It turned out that the finch parents only produced that particular call when it was very hot out. Upon hearing it from inside the egg, nestlings adjusted their development to prepare for the heat.

"I became very curious about how just hearing a sound before hatching could alter development," Mariette says.

She started searching for evidence in the literature of embryos using sound in other animals. She also dug into the neurobiology to try and understand how it could happen. So far, it's not clear exactly how it works, but the new report identifies some likely mechanisms.

"In crickets, when developing nymphs hear many sexy songs, female develop quickly to make the most of the opportunity, whereas males delay metamorphosis to grow bigger and invest more in reproduction," Mariette says. "In zebra finches, embryos exposed to parental heat calls grow less to reduce the physiological damage of heat exposure, which then allows them to produce more babies at adulthood. But embryos cannot decide to change their development, it just happens.

"This is because sound directly impacts behavior and physiology, without any conscious processing," she continues. "This is why, for example, music triggers spontaneous emotions of sadness or happiness, without us having to remember which movie that soundtrack came from, or in fact without us even noticing our reaction to the music. It seems to occur on its own, because there are direct connections in the brain between the auditory pathway and the areas that control emotion, reflex learning, and hormone production, so the higher cortical areas do not need to decode the information. Sound experienced early in life could trigger the same spontaneous reactions and, in fact, have long-lasting effects, because this is when the brain is developing, and consolidating connections. For the same reason, the downstream effects on physiology and then morphology can persist for life."

The bottom line for now is that sound has a much more profound impact on development than had been realized. Mariette suggest that it may be important to preserve natural soundscapes that may be crucial for animal adaptation, particularly in fast-changing environments.

Mariette's lab continues to study the physiological traits in zebra finches that may be affected by heat-calls. "It is quite amazing that sound alone can prepare babies for heat, particularly given the alarming rate of climate change," she says.

Skokie, IL - The International Society for Stem Cell Research (ISSCR), today released updated guidelines for stem cell research and its translation to medicine. The update reflects emerging advances including, stem cell-based embryo models, human embryo research, chimeras, organoids, and genome editing.

"The 2021 update presents practical advice for oversight of research posing unique scientific and ethical issues for researchers and the public," said Robin Lovell-Badge, PhD, FRS, Chair, ISSCR Guidelines task force and Senior Group Leader and Head of the Division of Stem Cell Biology and Developmental Genetics at The Francis Crick Institute, UK. "They provide confidence to researchers, clinicians, and the public alike that stem cell science can proceed responsibly, ethically, and remain responsive to public and patient interests," he said.

Scientists, research organizations, and scientific journals have long relied upon the ISSCR Guidelines as the international standard for scientific and ethical rigor, oversight, and transparency in stem cell research. The guidelines also provide a basis for implementation of new regulatory frameworks in countries without existing oversight systems. Adherence to the guidelines provides assurance that research is conducted with integrity and new therapies are safe, effective, and evidence-based.

"This is a significant update, building upon the society's longstanding commitment to excellence in all areas of stem cell research." said Christine Mummery, PhD, ISSCR president and professor of Developmental Biology at Leiden University Medical Center, the Netherlands. "The updates address new methods of understanding fundamental biological processes that may ultimately lead to the alleviation of debilitating diseases and disorders."

The 2021 ISSCR Guidelines update is the result of a two-year collaboration with international experts and respected leaders in areas of stem cell science, ethics, and law, and was peer-reviewed by scientists and ethicists from 14 countries. They are publicly available at isscr.org/guidelines.

Additional information is available here:

"Why stem cell guidelines needed an update: New criteria aim to reassure the public to permit progress in contentious research," by Lovell-Badge (Nature), publishing on 26 May 2021, 11:00 a.m. EDT

"ISSCR Guidelines for Stem Cell Research and Clinical Translation: The 2021 Update," by Lovell-Badge et al., ISSCR Guidelines Taskforce (Stem Cell Reports), under embargo until 26 May 2021, 11:00 a.m. EDT. Publishing on 27 May 2021, 11:00 a.m. EDT. 10.1016/j.stemcr.2021.05.012

"Human Embryo Research, Stem Cell-derived Embryo Models and In Vitro Gametogenesis: Considerations Leading to the Revised ISSCR Guidelines," Clark et al., (Stem Cell Reports), under embargo until 26 May 2021, 11:00 a.m. EDT. Publishing on 27 May 2021, 11:00 a.m. EDT. 10.1016/j.stemcr.2021.05.008

"ISSCR Guidelines for the Transfer of Human Pluripotent Stem Cells and Their Direct Derivatives into Animal Hosts," by Hyun et al. (Stem Cell Reports), under embargo until 26 May 2021, 11:00 a.m. EDT. Publishing on 27 May 2021, 11:00 a.m. EDT. 10.1016/j.stemcr.2021.05.005

"ISSCR's Guidelines for Stem Cell Research and Clinical Translation: Supporting the Development of Safe and Efficacious Stem Cell-Based Interventions," by Turner (Stem Cell Reports), under embargo until 26 May 2021, 11:00 a.m. EDT. Publishing on 27 May 2021, 11:00 a.m. EDT. 10.1016/j.stemcr.2021.05.011

Communities benefit from sharing knowledge and experience among their members. Following a similar principle - called "swarm learning" - an international research team has trained artificial intelligence algorithms to detect blood cancer, lung diseases and COVID-19 in data stored in a decentralized fashion. This approach has advantage over conventional methods since it inherently provides privacy preservation technologies, which facilitates cross-site analysis of scientific data. Swarm learning could thus significantly promote and accelerate collaboration and information exchange in research, especially in the field of medicine. Experts from the DZNE, the University of Bonn, the information technology company Hewlett Packard Enterprise (HPE) and other research institutions report on this in the scientific journal Nature.

Science and medicine are becoming increasingly digital. Analyzing the resulting volumes of information - known as "big data" - is considered a key to better treatment options. "Medical research data are a treasure. They can play a decisive role in developing personalized therapies that are tailored to each individual more precisely than conventional treatments," said Joachim Schultze, Director of Systems Medicine at the DZNE and professor at the Life & Medical Sciences Institute (LIMES) at the University of Bonn. "It's critical for science to be able to use such data as comprehensively and from as many sources as possible."

However, the exchange of medical research data across different locations or even between countries is subject to data protection and data sovereignty regulations. In practice, these requirements can usually only be implemented with significant effort. In addition, there are technical barriers: For example, when huge amounts of data have to be transferred digitally, data lines can quickly reach their performance limits. In view of these conditions, many medical studies are locally confined and cannot utilize data that is available elsewhere.

Data Remains on Site

In light of this, a research collaboration led by Joachim Schultze tested a novel approach for evaluating research data stored in a decentralized fashion. The basis for this was the still young "Swarm Learning" technology developed by HPE. In addition to the IT company, numerous research institutions from Greece, the Netherlands and Germany - including members of the "German COVID-19 OMICS Initiative" (DeCOI) - participated in this study.

Swarm Learning combines a special kind of information exchange across different nodes of a network with methods from the toolbox of "machine learning", a branch of artificial intelligence (AI). The linchpin of machine learning are algorithms that are trained on data to detect patterns in it - and that consequently acquire the ability to recognize the learned patterns in other data as well. "Swarm Learning opens up new opportunities for collaboration in medical research, as well as in business. The key is that all participants can learn from each other without having to share confidential data," said Dr. Eng Lim Goh, Senior Vice President and Chief Technology Officer for artificial intelligence at HPE.

In fact, with Swarm Learning, all research data remains on site. Only algorithms and parameters are shared - in a sense, lessons learned. "Swarm Learning fulfills the requirements of data protection in a natural way," Joachim Schultze emphasized.

Collaborative Learning

Unlike "federated learning", in which the data also remains locally, there is no centralized command center, the Bonn scientist explained. "Swarm Learning happens in a cooperative way based on rules that all partners have agreed on in advance. This set of rules is captured in a blockchain." This is a kind of digital protocol that regulates information exchange between the partners in a binding manner, it documents all events and all parties have access to it. "The blockchain is the backbone of Swarm Learning," Schultze said. "All members of the swarm have equal rights. There is no central power over what happens and over the results. So there is, in a sense, no spider controlling the data web."

Thus, the AI algorithms learn locally, namely on the basis of the data available at each network node. The learning outcomes of each node are collected as parameters through the blockchain and smartly processed by the system. The outcome, i. e. optimized parameters, are passed on to all parties. This process is repeated multiple times, gradually improving the algorithms' ability to recognize patterns at each node of the network.

Lung Images and Molecular Features

The researchers are now providing practical proof of this approach through the analysis of X-ray images of the lungs and of transcriptomes: The latter are data on the gene activity of cells. In the current study, the focus was specifically on immune cells circulating in the blood - in other words, white blood cells. "Data on the gene activity of blood cells are like a molecular fingerprint. They hold important information about how the organism reacts to a disease," Schultze said. "Transcriptomes are available in large numbers just like X-ray images, and they are highly complex. This is exactly the kind of information you need for artificial intelligence analysis. Such data is perfect for testing Swarm Learning."

The research team addressed a total of four infectious and non-infectious diseases: two variants of blood cancer (acute myeloid leukemia and acute lymphoblastic leukemia), as well as tuberculosis and COVID-19. The data included a total of more than 16,000 transcriptomes. The swarm learning network over which the data were distributed typically consisted of at least three and up to 32 nodes. Independently of the transcriptomes, the researchers analyzed about 100,000 chest X-ray images. These were from patients with fluid accumulation in the lung or other pathological findings as well as from individuals without anomalies. These data were distributed across three different nodes.

A High Rate of Success

The analysis of both the transcriptomes and the X-ray images followed the same principle: First, the researchers fed their algorithms with subsets of the respective data set. This included information about which of the samples came from patients and which from individuals without findings. The learned pattern recognition for "sick" or "healthy" was then used to classify further data, in other words it was used to sort the data into samples with or without disease. The accuracy, i.e. the ability of the algorithms to distinguish between healthy and diseased individuals, was around 90 percent on average for the transcriptomes (each of the four diseases was evaluated separately); in the case of the X-ray data, it ranged from 76 to 86 percent.

"The methodology worked best in leukemia. In this disease, the signature of gene activity is particularly striking and thus easiest for artificial intelligence to detect. Infectious diseases are more variable. Nevertheless, the accuracy was also very high for tuberculosis and COVID-19. For X-ray data, the rate was somewhat lower, which is due to the lower data or image quality," Schultze commented on the results. "Our study thus proves that Swarm Learning can be successfully applied to very different data. In principle, this applies to any type of information for which pattern recognition by means of artificial intelligence is useful. Be it genome data, X-ray images, data from brain imaging or other complex data."

The study also found that Swarm Learning yielded significantly better results than when the nodes in the network learned separately. "Each node benefits from the experience of the other nodes, although only local data is ever available. The concept of Swarm Learning has thus passed the practical test," Schultze said.

A Vision for the Future

"I am convinced that swarm learning can give a huge boost to medical research and other data-driven disciplines. The current study was just a test run. In the future, we intend to apply this technology to Alzheimer's and other neurodegenerative diseases," Schultze said. "Swarm Learning has the potential to be a real game changer and could help make the wealth of experience in medicine more accessible worldwide. Not only research institutions but also hospitals, for example, could join together to form such swarms and thus share information for mutual benefit."

New research published in Nature provides a powerful yet surprisingly simple way to determine the number of visitors to any location in a city.

Scientists* from the Santa Fe Institute, MIT, and ETH Zürich have discovered and developed a scaling law that governs the number of visitors to any location based on how far they are traveling and how often they are visiting. The visitation law opens up unprecedented possibilities for accurately predicting flows between locations, which could ultimately have applications in everything from city planning to preventing the spread of the next major pandemic.

"Imagine you are standing on a busy plaza, say in Boston, and you see people coming and going. This may look pretty random and chaotic, but the law shows that these movements are surprisingly structured and predictable. It basically tells you how many of these people are coming from 1, 2 or 10 kilometers away and how many are visiting once, twice or 10 times a month", says lead author Markus Schläpfer of ETH Zurich's Future Cities Laboratory. "And the best part is that this same regularity holds not only in Boston, but across cities worldwide."

The researchers' findings are a result of an analysis of mobile phone data from millions of anonymized cell phone users in highly diverse urban regions across the world, including Greater Boston in the United States, Lisbon in Europe, Singapore in Asia, and Dakar in Africa. Schläpfer began the analysis and development of the theory while he was a post-doctoral fellow at the Santa Fe Institute working together with senior author Geoffrey West, a physicist who leads the Cities, Scaling, and Sustainability project. It was later extended to include researchers at the MIT Sensible Cities Laboratory under the leadership of the architect Carlo Ratti.

Universally, they found that the number of visitors to any urban location scales as the inverse square of both travel distance from home and the visitation frequency. Like the gravitational pull of a large planet, an attractive city plaza with fine museums and famous shops draws relatively more visitors from more distant locations, though less frequently than those coming from nearby locations, their relative numbers being predictably determined by the inverse square law. A further surprising consequence of this new visitation law is that the same number of people visit the location whether they are coming from, say, 10km away 3 times a week, or from 3km away 10 times a week.

While previous research has used mobile phone data to study human movement from the perspectives of individual people -- where they go, when, and how often -- this is the first systematic study to focus on the frequency of visits from the perspective of places, using mobile phone data to understand the relative attractiveness or utility of an urban area.

"There's an optimization problem going on here in terms of the amount of energy people are using, the distance they're travelling, and the number of trips they're making," says Geoffrey West. "When we travel for leisure we choose our destinations. During everyday life, those choices are more forced because we have to go to work, say, five times a week, pick up the kids two times, etc. But there's this remarkable conservation inherent in the visitation law -- namely, the average amount of energy that people allocate to travel is the same whether they try to do it across different distances or at different frequencies."

Schläpfer says the new paper can give urban planners "a baseline for understanding which locations in their cities are over- or under-performing," in terms of the number of people they attract. It can inform planners about where to add amenities like parks and restaurants, or how much public transportation is needed for new urban developments.

The law of visitation joins a growing body of research in the science of cities, which SFI researchers and their collaborators have pioneered since 2007, when they first uncovered universal laws governing growth, innovation, and the pace of life in cities.

"All of the problems that we face, especially climate change are generated in cities because that's where the people are," West says. "So understanding cities, and how people move within them, plays into fundamental questions about the future of life on this planet."

What The Study Did: Researchers conducted a review of studies examining the frequency and variety of persistent symptoms after COVID-19 infection.

Authors: Steven N. Goodman, M.D., M.H.S., Ph.D., of Stanford University in Stanford, California, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2021.11417)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

In the human gut, good bacteria make great neighbors.

A new Northwestern University study found that specific types of gut bacteria can protect other good bacteria from cancer treatments -- mitigating harmful, drug-induced changes to the gut microbiome. By metabolizing chemotherapy drugs, the protective bacteria could temper short- and long-term side effects of treatment.

Eventually, the research could potentially lead to new dietary supplements, probiotics or engineered therapeutics to help boost cancer patients' gut health. Because chemotherapy-related microbiome changes in children are linked to health complications later in life -- including obesity, asthma and diabetes -- discovering new strategies for protecting the gut is particularly important for pediatric cancer patients.

"We were really inspired by bioremediation, which uses microbes to clean up polluted environments," said Northwestern's Erica Hartmann, the study's senior author. "Usually bioremediation applies to groundwater or soil, but, here, we have applied it to the gut. We know that certain bacteria can breakdown toxic cancer treatments. We wondered if, by breaking down drugs, these bacteria could protect the microbes around them. Our study shows the answer is 'yes.' If some bacteria can break down toxins fast enough, that provides a protective effect for the microbial community."

The research will be published on May 26 in the journal mSphere.

Hartmann is an assistant professor of environmental biology at Northwestern's McCormick School of Engineering. Ryan Blaustein, a former postdoctoral fellow in Hartmann's laboratory, is the paper's first author. He is now a postdoctoral fellow at the National Institutes of Health.

Although cancer treatments are life-saving, they also cause profoundly harsh and painful side effects, including gastrointestinal issues. Chemotherapies, in particular, can obliterate the healthy, "good" bacteria in the human gut.

"Chemotherapy drugs do not differentiate between killing cancer cells and killing microbes," Hartmann said. "Microbes in your gut help digest your food and keep you healthy. Killing these microbes is especially harmful for children because there's some evidence that disruption in the gut microbiome early in life can lead to potential health conditions later in life."

Working with Dr. Patrick Seed, a professor of pediatrics and microbiology-immunology at the Northwestern University Feinberg School of Medicine, Hartmann's lab learned from Raoultella planticola. Naturally occurring in the human gut in low abundances, Raoultella planticola can break down chemotherapy drug doxorubicin, which has been demonstrated in other research.

To test whether or not this breakdown effect could protect the entire microbiome, the team developed simplified microbial communities, which included various types of bacteria typically found in the human gut. The "mock gut communities" included bacteria strains (Escherichia coli and Klebsiella pneumoniae) that are good at breaking down doxorubicin, strains (Clostridium innocuum and Lactobacillus rhamnosus) that are especially sensitive to doxorubicin and one strain (Enterococcus faecium) that is resistant to doxorubicin but does not break it down.

The team then exposed these mock gut communities" to doxorubicin and found increased survival among sensitive strains. The researchers concluded that, by degrading doxorubicin, certain bacteria made the drugs less toxic to the rest of the gut.

Although the research highlights a promising new pathway for potentially protecting cancer patients, Hartmann cautions that translating the new findings into treatments is still far off.

"There are several eventual applications that would be great to help cancer patients -- particularly pediatric patients -- not experience such harsh side effects," she said. "But we're still far from actually making that a reality."

Flowering plants (angiosperms) dominate most terrestrial ecosystems, providing the bulk of human food. However, their origin has been a mystery since the earliest days of evolutionary thought.

Angiosperm flowers are hugely diverse. The key to clarifying the origin of flowers and how angiosperms might be related to other kinds of plants is understanding the evolution of the parts of the flower, especially angiosperm seeds and the fruits in which the seeds develop.

Fossil seed-bearing structures preserved in a newly discovered Early Cretaceous silicified peat in Inner Mongolia, China, provide a partial answer to the origin of flowering plants, according to a study led by Prof. SHI Gongle from the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS).

The study was published in Nature on May 26.

The fossils, which date from about 126 million years ago, support an earlier idea that the distinctive outer covering of developing seeds of flowering plants--the so-called second integument--is fundamentally comparable to structures that occur in certain extinct non-angiosperm seed plants from the "Age of Dinosaurs."

The seeds of cycads, ginkgo and conifers are enclosed and protected by a single integument, which is believed to correspond to the inner integument in flowering plants. However, the outer (second) integument is a unique structure. Its development is linked to its curious recurved form and is controlled by different genes than those responsible for the development of the inner integument.

These fossils, exceptionally well preserved and abundant in the silicified peat from China, have two seeds enclosed inside a specialized recurved structure--the cupule.

Similar cupules occur in several groups of extinct plants from the Mesozoic that are known only from fossils, and while it has been suggested some of these cupules may be precursors of the second integument of flowering plants, discussions have been hampered by inadequate information.

The new fossils from China, along with the reexamination of previously described fossils, suggest that the recurved cupules found in several groups of extinct seed plants from the Mesozoic are all fundamentally similar and are likely the precursors of the second integument of flowering plants.

The recurved structure seen in the young seeds of flowering plants is therefore a holdover from an earlier pre-angiosperm phase of evolution. Variation among extinct Mesozoic seed plants in the number of seeds per cupule and other features likely reflect differences relating to pollination, as well as seed output, protection and dispersal.

Recognition of extinct seed plants with a structure comparable to a key feature of living angiosperms provides a partial answer to the question of flowering plant origins. It also helps focus future work on understanding how living and fossil groups of seed plants are interrelated, and has important implications for ideas on the origin of another diagnostic feature of flowering plants that evidently came later--the carpel--the structure that forms the fruit wall in which the seeds develop.