Earth

A team led by researchers at Carnegie Mellon University has created a new technology that enhances scientists' ability to communicate with neural cells using light. Tzahi Cohen-Karni, associate professor of biomedical engineering and materials science and engineering, led a team that synthesized three-dimensional fuzzy graphene on a nanowire template to create a superior material for photothermally stimulating cells. NW-templated three-dimensional (3D) fuzzy graphene (NT-3DFG) enables remote optical stimulation without need for genetic modification and uses orders of magnitude less energy than available materials, preventing cellular stress.

Graphene is abundant, cheap, and biocompatible. Cohen-Karni's lab has been working with graphene for several years, developing a technique of synthesizing the material in 3D topologies that he's labeled "fuzzy" graphene. By growing two-dimensional (2D) graphene flakes out-of-plane on a silicon nanowire structure, they're able to create a 3D structure with broadband optical absorption and unparalleled photothermal efficiency.

These properties make it ideal for cellular electrophysiology modulation using light through the optocapacitive effect. The optocapacitive effect alters the cell membrane capacitance due to rapidly applied light pulses. NT-3DFG can be readily made in suspension, allowing the study of cell signaling within and between both 2D cell systems and 3D, like human cell-based organoids.

Systems like these are not only crucial to understanding how cells signal and interact with each other, but also hold great potential for the development of new, therapeutic interventions. Exploration into these opportunities, however, has been limited by the risk of cellular stress that existing optical remote-control technologies present. The use of NT-3DFG eliminates this risk by using significantly less energy, on a scale of 1-2 orders of magnitude less. Its biocompatible surface is easy to modify chemically, making it versatile for use with different cell types and environments. Using NT-3DFG, photothermal stimulation treatments could be developed for motor recruitment to induce muscle activation or could direct tissue development in an organoid system.

"This is an outstanding collaborative work of experts from multiple fields, including neuroscience through Pitt and UChicago, and photonics and materials science through UNC and CMU," said Cohen-Karni. "The developed technology will allow us to interact with either engineered tissues or with nerve or muscle tissue in vivo. This will allow us to control and affect tissue functionality using light remotely with high precision and low needed energies."

Additional contributions to the project were made by Maysam Chamanzar, assistant professor of electrical and computer engineering. His team's core expertise in photonics and neurotechnologies assisted in developing the much-needed tools to allow both the characterization of the unique hybrid-nanomaterials, and in stimulating the cells while optically recording their activity.

"The broadband absorption of these 3D nanomaterials enabled us to use light at wavelengths that can penetrate deep into the tissue to remotely excite nerve cells. This method can be used in a whole gamut of applications, from designing non-invasive therapeutics to basic scientific studies," said Chamanzar.

The team's findings are significant both for our understanding of cell interactions and the development of therapies that harness the potential of the human body's own cells. Nanostructures created using NT-3DFG may have a major impact on the future of human biology and medicine.

The notion of conserving climate change refugia - areas relatively buffered from current climate change that shelter valued wildlife, ecosystems, and other natural resources - is only about 10 years old, but the field has matured enough that a leading journal has prepared a special issue on the topic.

It offers "a look back at how far we've come and a view forward to the work that is still needed," says editor Toni Lyn Morelli, a research ecologist at the U.S. Geological Survey's Northeast Climate Adaptation Center (NE CASC) at the University of Massachusetts Amherst. "I believe this is the first time there has been a special issue devoted to climate-change refugia" she adds, "so we think it will spur conservation and innovation."

The 100-page issue of Frontiers in Ecology and the Environment organized by Morelli features a new synthesis of developments in refugia science, plus eight articles by experts in the field and an editorial by paleo-ecologist and director of the Southwest and South Central Climate Adaptation Science Centers, Stephen Jackson.

Jackson says, "As in the case of the Covid-19 pandemic, our best hope is to render the climate change wave low and slow, reducing impacts and buying time to study, prepare, understand and adapt." The introductory article outlines how climate-change refugia can serve as a "slow lane" to protect native species and ecosystems from the negative effects of climate change and as safe havens for biodiversity and ecosystems in the longer term.

The special issue covers a variety of topics, including refugia related to fish and wildlife, rivers and wetlands, mountains and forests - plus conceptual advances and examples of the successful application of refugia maps and data to management questions.

Author Diana Stralberg at the University of Alberta, Canada, points out, "We are trying to find those areas where things are moving a bit more slowly in terms of climate change and where plants and animals have more opportunity to survive, whether they are already living there or could shift into those areas."

Morelli is a founding member of the Refugia Research Coalition (RRC), a network of scientists, resource managers, and others associated with the Climate Adaptation Science Centers, particularly the Northwest CASC hosted by the University of Washington and its Northeast counterpart hosted by UMass Amherst. (hyperlink: climaterefugia.org).

"We formed the RRC about five years ago to share ideas, hold workshops, engage with practitioners, and share our science," Morelli recalls. The group's diversity of research, expertise and approaches gave her the idea for a special issue.

"We wanted to synthesize the science around climate change refugia over the last 10 years, to identify gaps and opportunities for the future, and highlight successes in applications that have been developed for management and conservation," she notes. "I was extremely fortunate to work with such a dynamic and accomplished group of co-authors," Morelli adds.

Boulder, Colo., USA: A common message in use to convey the seriousness of climate change to the public is: "Carbon dioxide levels are higher today than they have been for the past one million years!" This new study by Brian Schubert (University of Louisiana at Lafayette) and coauthors Ying Cui and A. Hope Jahren used a novel method to conclude that today's carbon dioxide (CO2) levels are actually higher than they have been for the past 23 million years.

The team used the fossilized remains of ancient plant tissues to produce a new record of atmospheric CO2 that spans 23 million years of uninterrupted Earth history. They have shown elsewhere that as plants grow, the relative amount of the two stable isotopes of carbon, carbon-12 and carbon-13 changes in response to the amount of CO2 in the atmosphere. This research, published this week in Geology, is a next-level study measuring the relative amount of these carbon isotopes in fossil plant materials and calculating the CO2 concentration of the atmosphere under which the ancient plants grew.

Furthermore, Schubert and colleagues' new CO2 "timeline" revealed no evidence for any fluctuations in CO2 that might be comparable to the dramatic CO2 increase of the present day, which suggests today's abrupt greenhouse disruption is unique across recent geologic history.

Another point, important to geological readers, is that because major evolutionary changes over the past 23 million years were not accompanied by large changes in CO2, perhaps ecosystems and temperature might be more sensitive to smaller changes in CO2 than previously thought. As an example: The substantial global warmth of the middle Pliocene (5 to 3 million years ago) and middle Miocene (17 to 15 million years ago), which are sometimes studied as a comparison for current global warming, were associated with only modest increases in CO2.

NEW YORK, NY (June 1, 2020) - A new study published today in Neuron led by The New York Stem Cell Foundation (NYSCF) Research Institute's Valentina Fossati, PhD, creates astrocytes - an integral support cell in the brain - from stem cells and shows that in disease-like environments, these normally helpful cells can turn into neuron-killers.

"We can now create stem cells from any individual and see in the dish how astrocytes play a role in diseases like multiple sclerosis, Parkinson's, and Alzheimer's," remarked NYSCF CEO Susan L. Solomon. "This will shed new light on the devastating process of neurodegeneration, pointing us towards effective treatments for this growing group of patients."

Creating Astrocytes from Stem Cells

Astrocytes, star-shaped cells that make up more than half the cells in the central nervous system, belong to a category of brain cells called glia which provide vital support for neurons in the brain. Astrocytes aid in metabolic processes, regulate connectivity of brain circuits, participate in inflammatory signaling, and help regulate blood flow across the blood-brain barrier, among other duties. They are a crucial component of brain function but are often overlooked in research and drug development, although recent mounting evidence implicates them in many neurological diseases.

Most studies of astrocytes have been done in mouse models, but it has been shown that mouse astrocytes are not quite the same as human astrocytes. This means that many aspects of human astrocyte function, including some behaviors that may be relevant to disease, are not fully captured by mouse models.

"The field needed a reliable method for making human astrocytes from stem cells so that we can better investigate how they may be contributing to neurodegenerative diseases," explained Dr. Fossati, a Senior Research Investigator at the NYSCF Research Institute. "Previously, drugs that failed have not specifically targeted astrocytes. Now, drugs targeting astrocyte malfunctions can be identified using patient cells."

Dr. Fossati's team built on their previously published protocols for converting stem cells into glial cells such as microglia (the brain's immune cells) and oligodendrocytes (cells that aid in neuronal communication) to identify a protein marker, CD49f, that is expressed in astrocytes and can be used to isolate them from mixed cell populations in a lab dish or the human brain, facilitating downstream research.

"We were excited to see that our stem-cell-derived astrocytes isolated with CD49f behaved the way typical astrocytes do: they take up glutamate, respond to inflammation, engage in phagocytosis - which is like 'cell eating' - and encourage mature firing patterns and connections in neurons," said Dr. Fossati.

The team also confirmed that CD49f is present in astrocytes found in human brain tissue.

"We looked at human brain tissue samples from both a healthy donor and a patient with Alzheimer's disease and found that these astrocytes also expressed CD49f - suggesting that this protein is a reliable indicator of astrocyte identity in both health and disease."

When Astrocytes Go Rogue

Armed with a protocol for creating functional astrocytes from stem cells, the team then turned their attention to how these astrocytes begin to misbehave in disease.

Recent work from Shane Liddelow, PhD, of New York University (NYU), a collaborator on the study, found that astrocytes can 'go rogue,' becoming toxic to the neurons they typically support.

"We observed in mice that astrocytes in inflammatory environments take on a reactive state, actually attacking neurons rather than supporting them," explained Dr. Liddelow, Assistant Professor of Neuroscience and Physiology and of Ophthalmology at the NYU Grossman School of Medicine. "We found evidence of reactive astrocytes in the brains of patients with neurodegenerative diseases, but without a human stem cell model, it wasn't possible to figure out how they were created and what they are doing in patient brains."

Dr. Fossati sought to use her human stem cell model to determine if what Dr. Liddelow observed in mice could also be happening in humans. Her team exposed healthy stem-cell-derived astrocytes to inflammation - essentially mimicking the environment of the brain in neurodegenerative diseases - collected their byproducts, and then exposed these secretions to healthy neurons.

"What we saw in the dish confirmed what Dr. Liddelow saw in mice: the neurons began to die," said Dr. Fossati. "Observing this 'rogue astrocyte' phenomenon in a human model of disease suggests that it could be happening in actual patients and opens the door for new therapeutics that intervene in this process."

The team also saw that stem-cell-derived astrocytes exposed to inflammation lost their typical astrocyte functions: they did not support neuronal maturation or firing very well, and they didn't uptake as much glutamate. They also changed their morphology, losing their characteristic 'long arms' and taking on a more constricted star-like shape.

"Along with secreting a toxin that kills neurons, we also saw that stem-cell-derived astrocytes in disease-like environments simply do not perform their typical jobs as well, and that could lead to neuronal dysfunction," noted Dr. Fossati. "For example, since they do not take up glutamate properly, too much glutamate is likely left around the neurons, which could cause a neuron to atrophy, and that's something we can potentially target in new therapies."

Altogether, these findings open up exciting new avenues of study and provide researchers with a new system to explore mechanisms of disease.

"I'm looking forward to using our new system to further explore the intricacies of astrocyte function in Alzheimer's, multiple sclerosis, Parkinson's, and other diseases," remarked Dr. Fossati. "We have already seen intriguing behaviors that may explain how neurodegeneration occurs, and I am hopeful that this work will point us toward new treatment opportunities for these patients."

Rockville, MD (June 1, 2020) - Warning labels on sugary drinks lead to healthier drink choices, according to new analysis of more than 20 studies examining these warnings. The new findings could help inform policymakers, who are increasingly interested in implementing policies requiring warning labels for sugar-sweetened beverages. Sugary drinks (also known as sugar sweetened beverages) refer to beverages with added sugar or other sweeteners, such as soda, sports drinks or fruit-flavored drinks.

"Our findings suggest that sugary drink warnings help consumers better understand products' healthfulness and encourage consumers to make healthier choices about what drinks to buy," said research team leader Anna H. Grummon, Ph.D., a David E. Bell Postdoctoral Fellow at Harvard T.H. Chan School of Public Health. "These results highlight the potential usefulness of sugary drink warning policies in both informing consumers and reducing consumption of unhealthy beverages like sodas, energy drinks and fruit-flavored drinks."

Grummon will present the research as part of NUTRITION 2020 LIVE ONLINE, a virtual conference hosted by the American Society for Nutrition (ASN).

"As policymakers' interest in this policy has grown, so too has research on sugary drink warnings," said the study's co-author Marissa G. Hall, Ph.D., assistant professor at the University of North Carolina in Chapel Hill. "However, skeptics worry that warnings won't be effective at informing consumers or encouraging healthier choices, and no research had synthesized existing evidence on sugary drink warnings to address these questions."

To fill this knowledge gap, the researchers identified 23 experimental studies of sugary drink warnings with data from 16,241 individuals. They then applied meta-analysis, a statistical technique that combines results from many studies. This approach allowed the researchers to create a detailed and comprehensive picture of existing research on sugary drink warnings. The meta-analysis indicated that, on average across studies, sugary drink warnings led to statistically significant reductions in sugary drink purchases.

"It is clear that sugary drink warnings can help consumers make healthier choices about the drinks they buy," said Grummon. "Now, we are studying the best ways to design warnings to maximize their benefits. For example, should warnings include icons or pictures that help communicate the warnings' message?"

The researchers are also exploring the effects of other types of messages to encourage healthier diets, for example, messages that encourage people to drink more water.

Due to the cancellation of the Nutrition 2020 meeting, which was to be held in Seattle, this abstract will be presented as part of ASN's virtual meeting, NUTRITION 2020 LIVE ONLINE, which will be held from June 1-4, 2020. Contact the media team for more information or register to access the virtual content.

Image available.

This release may include updated numbers or data that differ from those in the abstract submitted to NUTRITION 2020 LIVE ONLINE.

Please note that abstracts presented at NUTRITION 2020 LIVE ONLINE were evaluated and selected by a committee of experts but have not generally undergone the same peer review process required for publication in a scientific journal. As such, the findings presented should be considered preliminary until a peer-reviewed publication is available.

Many of us are eating differently during the COVID-19 pandemic, and some are taking the stay-at-home lifestyle as an opportunity to work on weight loss goals. Get the latest research findings on fad diets, losing weight and healthful eating at NUTRITION 2020 LIVE ONLINE, a virtual conference featuring leading nutrition experts from around the world.

NUTRITION 2020 LIVE ONLINE is hosted by the American Society for Nutrition (ASN), the preeminent professional organization for nutrition research scientists and clinicians. ASN's flagship meeting, Nutrition 2020, was canceled due to the impacts of COVID-19. Attend the meeting for free online or contact the media team for more information.

Dieting risks

Is your weight loss diet giving you enough nutrients?

Micronutrients are important for keeping your body healthy and warding off disease. In a year-long randomized controlled trial, researchers found that 54 people following one of two diets--a low-carbohydrate diet or a high-fiber, bean-rich diet--showed similar results in terms of weight loss but were deficient in some micronutrients. While nutrient content varied between the two diets, participants in both groups consumed less than the recommended daily amount of vitamin D, vitamin E, calcium, magnesium and copper.

Neal G. Malik, California State University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

When healthy eating becomes an obsession

A new study suggests weight-loss diets may go hand-in-hand with orthorexia nervosa, a potentially damaging obsession with healthy eating. An internet survey of more than 400 college students found more than three-quarters of respondents who reported following a weight loss diet also showed signs of orthorexia, compared to less than 40% among those who were not dieting. Those following a weight loss diet also showed a much higher risk for other eating disorders.

Zhiping Yu, University of North Carolina at Chapel Hill, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Looking beyond food

Can gut microbes help--or hinder--weight loss?

While the microbes living in and on our bodies play a big role in our health, little is known about how they influence weight loss efforts. New research suggests that the type of bacteria in a person's gut may help predict their likelihood of weight-loss success. Out of 36 people participating in a six-month weight loss program, the 12 participants who succeeded in losing the targeted amount of weight (5% weight loss) showed lower concentrations of certain bacteria and higher concentrations of others at baseline compared to participants who did not lose weight. The findings suggest gut microbes may influence weight loss by affecting how the body processes food, researchers say.

Moira K. Differding, Johns Hopkins Bloomberg School of Public Health, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Exercise brings no weight loss boost compared to diet alone

A study involving 383 overweight adults found that following a calorie-restricted diet resulted in roughly the same amount of weight loss regardless of a person's level of physical activity. After one year of limiting their intake to 1,200-1,800 calories per day, participants lost just over 20 pounds on average, but the amount of weight lost was not significantly different among participants who exercised an average of 1.5 hours per week compared to those exercising nearly 4 hours per week. The researchers also found that participants' level of physical activity did not affect their ability to keep their calorie and fat consumption within bounds.

Carli A. Ligouri, University of Pittsburgh, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Nutrition tech

How reliable are commercial nutrition apps?

Researchers examined how calories and nutrients are calculated in two commercial nutrition apps--CalorieKing and MyFitnessPal--compared to a reference database used by scientists, the University of Minnesota Nutrition Coordinating Center Nutrition Data System for Research (NDSR). Overall, the apps were similar to the NDSR in counting calories and nutrients for the 50 most commonly consumed foods, with a few exceptions. MyFitnessPal was less reliable in its assessment of total fat and fiber intake for all foods, and was especially unreliable when it came to calculating calories, carbohydrates and fiber content of fruits. This variability underscores the need to compare nutrition apps with validated data sources if they are to be used in research and practice, researchers say.

Annie W. Lin, Northwestern University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Personalized weight loss program does not bring added confidence

Researchers are exploring whether a weight loss diet can be made more effective by accounting for how a person's body responds to specific foods. Early results from the three-month data involving 75 participants suggest this personalized approach has no effect on how people perceive their ability to resist overeating compared to a one-size-fits-all diet. The researchers plan to continue the study to examine how a personalized diet might affect participants' confidence or actual weight loss in the longer term.

Lu Hu, New York University, is the presenting author. This research will be presented as a virtual abstract presentation beginning June 1 at 12 p.m. EDT.

Professor Fabien Sorin and doctoral assistant Andreas Leber, at the Laboratory of Photonic Materials and Fibre Devices (FIMAP) in EPFL's School of Engineering, have developed a technology that can be used to detect a body's movements - and a whole lot more. "Imagine clothing or hospital bed sheets capable of monitoring your breathing and physical gestures, or AI-powered textiles that allow humans to interact more safely and intuitively with robots" says Leber. "The flexible transmission lines that we've developed can do all of this."

Stretching, pressure and torque

The researchers invented a single sensor that can detect different kinds of fabric deformation like stretching, pressure and torque at the same time. "Finding a method for calculating all that was our biggest challenge, because it's really difficult for sensors to measure several movements simultaneously," says Leber. "Also, conventional sensors have several drawbacks. First, they are fragile and break easily. Second, you need a lot of them to cover a large area, which eliminates many of the advantages of fabrics. And third, each type of conventional sensor can detect only one kind of deformation."

But by incorporating concepts from reflectometry, Sorin and Leber were able to create flexible fiber-shaped sensors that open up new doors for smart textiles. "Our technology works similar to a radar, but it sends out electrical impulses instead of electromagnetic waves," explains Leber. "Our fiber sensors operate like transmission lines for high-frequency communication. The system measures the time between when a signal is sent out and when it's received, and uses that to determine the exact location, type and intensity of deformation." This kind of detection technology has never before been used in applications requiring high mechanical flexibility and powerful electronic performance, which are two key features for distortion identification.?

Liquid metal and fiber optics

Creating the fibers is a complex task involving liquid metal, which serves as the conductor, and an optical fiber fabrication process. "The structure is just a few micrometers thick and has to be perfect, otherwise it won't work," says Leber. With these fibers, the entire surface of a fabric becomes one large sensor. "The trick was to create transmission lines made entirely of flexible materials, using a simple method that can be scaled up easily," adds Sorin. The team's research drew on a variety of disciplines including electrical engineering, mechanical engineering, materials science and process engineering. The next step will be to make the technology more portable by shrinking the electronic component.

The 26th Conference of the Parties (COP26) to the UN Framework Convention on Climate Change (UNFCCC) was scheduled to be held in Glasgow, Scotland in November 2020, and was expected to gather thousands of negotiators, policymakers, researchers, journalists and campaigners.

Due to the COVID-19 pandemic, Parties decided to postpone this big event, instead of moving it online as they did with smaller meetings in the past months. As announced a few days ago, COP26 will now take place between 1 and 12 November 2021 in Glasgow.

In the Correspondence "A digital climate summit to maintain Paris Agreement ambition", just published on Nature Climate Change, a team of scientists from the CMCC Foundation - Euro-Mediterranean Center on Climate Change, Ca' Foscari University of Venice and University College London (UCL) call for re-thinking the way climate diplomacy works, and the role digital technology can play in making the UNFCCC process transparent and accessible to everyone. They suggest a "digital COP26-Part 1" as a way to complement, rather than substitute, COP26 next year and to support climate ambition throughout 2020. This year is indeed crucial for climate action, as Parties are called to submit strengthened climate action plans - the Nationally Determined Contributions (NDCs) - and to publish long-term decarbonization strategies.

If technical feasibility would not be an issue, as demonstrated by many ongoing efforts to move crowded in-person meetings online, there are many reasons why a totally digital climate summit might not be as effective as a traditional one. Besides issues of real-time translation into the six UN languages" explains Elisa Calliari, researcher at CMCC Foundation, UCL and Ca'Foscari University of Venice, "the digital divide between developed and developing countries could result in an additional source of power asymmetry within the UNFCCC process. Moreover, a digital negotiation would ask to renounce to face-to-face diplomacy, which plays an important role in building trust and fostering international cooperation. Yet, after having participated to COPs for many years now, we wonder whether these mega-events are the most efficient and effective way to foster cooperation on climate action".

Hence, the team suggests that securing the benefits of face-to-face negotiation does not necessarily imply postponing all the formal announcements and side events that every year make COPs crowded. "We suggest imagining a new format, which can maintain political momentum for climate action while ensuring participation from business, research and civil society. A 'digital COP26-Part 1' can serve this purpose, as a virtual space where all the aspects that do not need to be formally negotiated by countries can be announced and discussed" explains Jaroslav Mysiak, director of the 'Risk assessment and adaptation strategies' Division at Fondazione CMCC. "Parties' unilateral pledges on more ambitious national climate plans and strategies to reach net zero emissions by 2050 can be announced in this virtual space, together with their climate finance commitments and initiatives to strengthen communities' resilience. Moreover, our proposal includes the translation into video conferences of the rich programme of side-events, which characterizes COP each year".

Durham, NC - The gene p53 is extremely important in cell biology and, hence, the world of cell replacement therapy. Its role is to regulate the cell cycle and halt the formation of tumors, leading to its nickname the "tumor suppressor gene." However, previous efforts to determine whether p53 is behind programmed cellular death (apoptosis) induced by DNA damage in pluripotent embryonic stem cells (ESCs) produced conflicting results. Initial studies said that it was not; later studies concluded that it was.

A new study released today in STEM CELLS sorts through this maze of contradictions to finally determine that the multiple roles of p53 in cell cycle regulation and apoptosis are acquired during pluripotent stem cell differentiation.

Melvin L. DePamphilis, Ph.D., section chief of Eukaryotic DNA Replication at the National Institute of Child Health & Human Development, Bethesda, MD., conducted the study along with his Institute colleagues Sushil K. Jaiswal, Ph.D., and John J. Oh, post-baccalaureate trainee. "If ESCs are to be used to form the basis of cell replacement therapies, then identifying the role or roles of p53 in pluripotent stem cells is essential," he said. "Our goal was to finally resolve this question of whether p53 is essential for inducing cell cycle arrest and/or apoptosis prior to ESC differentiation."

The majority of earlier studies used a chemotherapy drug called Adriamycin/doxorubicin (ADR) to induce apoptosis. ADR impacts DNA replication and mitosis, resulting in the accumulation of double-stranded DNA breaks in proliferating cells. Damaged DNA can trigger p53 to initiate apoptosis and prevent the duplication of damaged chromosomes. As the levels of p53 rise, they prompt production of a protein called p21, which enforces a halt in the cycle dictated by p53. It does this by binding to and inhibiting the activity of the Cdk/cyclin complexes, whose job is to switch the cell cycle off and allow time for the damaged DNA to be repaired.

In the current study, the Institute team likewise induced apoptosis using a 40-fold range of ADR concentrations as well as other chemotherapy drugs (staurosporine and WX8), all tested over a 50-fold range of cell seeding densities. To eliminate the possibility that conclusions depended on either the source or derivation of p53-/- ESCs, both wild-type and p53-/- ESCs derived directly from mouse blastocysts were characterized in parallel with ESCs in which the p53 genes were ablated in vitro from ESCs harboring conditional p53 gene knockouts. "ESCs isolated from p53-/- blastocysts presented a chronic phenotype, whereas p53-/- ESCs engineered in vitro presented an acute phenotype that could be compared directly with their parental ESCs," Dr. Jaiswal explained.

The results showed that regardless of derivation the ESCs did not require p53, p21 or PUMA (another critical protein involved in apoptosis that is induced by p53) either to activate the G2-checkpoint, which ensures that cells don't initiate mitosis until damaged DNA is repaired, or to undergo apoptosis rapidly and efficiently. "The effects of ADR concentration and cell confluency were marginal, but the effects of cell differentiation were dramatic; p53 dependent regulation of cell division and apoptosis were acquired during p53-dependent cell differentiation," Mr. Oh said.

These results led the researchers to conclude that the study "unequivocally" demonstrates that the multiple roles of p53 in cell cycle regulation and apoptosis are first acquired during pluripotent stem cell differentiation.

"The new report by Jaiswal et al. is extremely important in reconciling contradictory results concerning the role of p53 in the stem cell field," said Dr. Jan Nolta, Editor-in-Chief of STEM CELLS. "The authors have now definitely shown that the importance of p53 in cell cycle arrest and initiation of apoptosis is first acquired during the differentiation of pluripotent stem cells."

Professor Fabien Sorin and doctoral assistant Andreas Leber, at the Laboratory of Photonic Materials and Fibre Devices (FIMAP) in EPFL's School of Engineering, have developed a technology that can be used to detect a body's movements - and a whole lot more. "Imagine clothing or hospital bed sheets capable of monitoring your breathing and other vital movements, or AI-powered textiles that allow robots to interact more safely and intuitively with humans" says Leber. "The soft transmission lines that we've developed open the door to all of this."

Stretching, pressing and twisting

The researchers invented a sensor that can detect different kinds of fabric deformation such as stretch, pressure and torque - all at the same time. "Finding a method for differentiating all these convoluted movements was our biggest challenge, because it is very difficult for sensors to measure several stimulations simultaneously," says Leber. "Also, conventional sensors in textiles have several drawbacks. First, they are fragile and break easily. Second, you need a lot of them to cover a large area, which eliminates many of the advantages of fabrics. And third, each type of conventional sensor can detect only one kind of deformation."

But by incorporating concepts from reflectometry, Sorin and Leber were able to create soft fiber-shaped sensors that open up new doors for smart textiles. "Our technology works similar to a radar, but it sends out electrical pulses instead of electromagnetic waves," explains Leber. "That means our fiber sensors operate like transmission lines, known from high-frequency communication. The system measures the time between when a signal is sent out and when it's received, and uses that to determine the exact location, type and intensity of deformation." This kind of detection technology has never before been used in structures combining extended mechanical flexibility and high electronic performance, which are key for measuring deformations.?

Liquid metal and fiber optics processing

Creating the fibers is a complex task involving an optical fiber fabrication process applied to unusual materials such as elastomers or liquid metals that serve as the conductors. "The structure includes micrometer-size features and has to be perfect, otherwise it won't work," says Leber. With these fibers, the entire surface of a fabric becomes one large sensor. "The trick was to create transmission lines made entirely of soft materials, using a simple method that can be scaled up," adds Sorin. The team's research drew on a variety of disciplines including electrical engineering, mechanical engineering, and materials science. The next step will be to make the technology more portable by reducing the footprint of peripheral electronics.

Probiotic supplements are widely available and are sometimes promoted as a general way to support the gut microbiome and promote health. But a higher bar for probiotic use exists in medical settings, where probiotics are more apt to be used for specific purposes.

A new publication in the Journal of Family Practice summarizes the latest evidence on using probiotics for a variety of specific health conditions, providing practical recommendations to assist primary care physicians in advising their patients and answering questions about probiotics.

The article, authored by current International Scientific Association for Probiotics and Prebiotics board members Daniel J. Merenstein, MD, Mary Ellen Sanders, PhD, and Daniel J. Tancredi, PhD, shows evidence supporting the use of probiotics for the following health issues: prevention of antibiotic-associated diarrhea, reducing crying time in infants with colic, improving the effectiveness of antibiotics for bacterial vaginosis, reducing the risk of Clostridioides (formerly Clostridium) difficile infections, treating acute pediatric diarrhea, and managing symptoms of constipation.

"Probiotics are not the same as drugs, but it's still important for physicians to recommend them in an evidence-based manner," says lead author Dr. Daniel J. Merenstein, Professor of Family Medicine at Georgetown University Medical Center in Washington, DC. "In this article, we summarize the evidence that has emerged in the scientific literature, getting as specific as possible about which probiotic strains are appropriate for which health indications."

In addition to practice recommendations for primary care physicians, the article includes a table of probiotic strains with evidence supporting their use; answers for patients' frequently asked questions; and examples of probiotic recommendations by global medical organizations.

A new study by researchers from Waseda University and the University of Tokyo found that orbital ordering in a vanadate compound exhibits a clear nucleation-growth behavior.

"We believe that this is the first observation of its kind, where electrons in an inorganic solid created two soft phases similar to vapor and water, and where a nucleation-growth behavior was observed due to the surface tension created between the phases," says Takuro Katsufuji, professor of physical sciences at Waseda University and principal investigator of this study.

The researchers published their peer-reviewed findings in Nature Communications on May 11, 2020.

When water vapor condenses, the vapor turns into dew as water nuclei form and grow, transitioning phases from gas to liquid. This formation and growth of the nuclei is called the nucleation-growth process, and it occurs in various types of phase transitions.

Though phase transitions also occur in solids, a nucleation-growth behavior has never been observed during electron-based phase transitions in inorganic materials. The most likely explanation is because there needs to be surface tension for this behavior to occur, but the hard solids could only create negligible surface tension compared with a bulk elastic energy.

In their study, Katsufuji and his team used the vanadate compound BaV10O15, an oxide with vanadium and barium. Previously, they found that at 130K, or approximately -140°C, the direction of orbitals possessed by the vanadium's electrons align, triggering a phase transition known as orbital ordering in this compound.

"Knowing this, what we did in our recent study was to partially replace vanadium with titanium, a chemical element located on the left of vanadium on the periodic table, to control the transition temperature of the orbital ordering," Katsufuji explains. "We revealed that the nucleation-growth process was happening by measuring the time dependence of the electrical resistivity, magnetic susceptibility, and the strain in the orbital ordering of this vanadate, and discovered that the electrons had created two vapor-water like soft phases in this organic solid and that there was surface tension between the two phases."

In the past, methods to obtain desirable characteristics with two-phase coexistence in solids have been tested with various materials and devices, but in most cases, it has been difficult to control the volume ratio and the forms of the two phases. However, it is expected that for these newly discovered soft phases, controlling the volume ratio and its forms could be done more easily. Also, BaV10O15 is known for its excellent performance as a thermoelectric material that can generate electricity from temperature difference, making this compound with two phases coexisting an attractive material.

Katsufuji adds, "The reason why nucleation-growth process occurs in BaV10O15 is because the surface tension between the two phases is quite large as a result of the coupling of degrees of freedom called orbitals and spins in electrons. We hope to progress research from the perspective that this is a new phenomenon that arises from such coupled degrees of freedom of electrons."

The researchers plan to measure various physical quantities of the vanadate compound at a state where the two phases coexist and understand how its physical properties can change as well as how its characteristics can improve as a functional material. Further, BaV10O15 is the first material as an inorganic compound where nucleation-growth process was observed, but it will be necessary to find whether there are other materials that exhibit nucleation-growth behavior.

Warming ocean temperatures and acidification drastically reduce the skeletal strength and filter-feeding capacity of glass sponges, according to new UBC research.

The findings, published in Scientific Reports, indicate that ongoing climate change could have serious, irreversible impacts on the sprawling glass sponge reefs of the Pacific Northwest and their associated marine life - the only known reefs of their kind in the world.

Ranging from the Alaska-Canada border and down through the Strait of Georgia, the reefs play an essential role in water quality by filtering microbes and cycling nutrients through food chains. They also provide critical habitat for many fish and invertebrates, including rockfish, spot prawns, herring, halibut and sharks.

"Glass sponge reefs are 'living dinosaurs' thought to have been extinct for 40 million years before they were re-discovered in B.C. in 1986," said Angela Stevenson, who led the study as a postdoctoral fellow at UBC Zoology. "Their sheer size and tremendous filtration capacity put them at the heart of a lush and productive underwater system, so we wanted to examine how climate change might impact their survival."

Although the reefs are subject to strong, ongoing conservation efforts focused on limiting damage to their delicate glass structures, scientists know little about how these sponges respond to environmental changes.

For the study, Stevenson harvested Aphrocallistes vastus, one of three types of reef-building glass sponges, from Howe Sound and brought them to UBC where she ran the first successful long-term lab experiment involving live sponges by simulating their natural environment as closely as possible.

She then tested their resilience by placing them in warmer and more acidic waters that mimicked future projected ocean conditions.

Over a period of four months, Stevenson measured changes to their pumping capacity, body condition and skeletal strength, which are critical indicators of their ability to feed and build reefs.

Within one month, ocean acidification and warming, alone and in combination, reduced the sponges' pumping capacity by more than 50 per cent and caused tissue losses of 10 to 25 per cent, which could starve the sponges.

"Most worryingly, pumping began to slow within two weeks of exposure to elevated temperatures," said Stevenson.

The combination of acidification and warming also made their bodies weaker and more elastic by half. That could curtail reef formation and cause brittle reefs to collapse under the weight of growing sponges or animals walking and swimming among them.

Year-long temperature data collected from Howe Sound reefs in 2016 suggest it's only a matter of time before sponges are exposed to conditions which exceed these thresholds.

"In Howe Sound, we want to figure out a way to track changes in sponge growth, size and area and area in the field so we can better understand potential climate implications at a larger scale," said co-author Jeff Marliave, senior research scientist at the Ocean Wise Research Institute. "We also want to understand the microbial food webs that support sponges and how they might be influenced by climate cycles."

Stevenson credits bottom-up community-led efforts and strong collaborations with government for the healthy, viable state of the B.C. reefs today. Added support for such community efforts and educational programs will be key to relieving future pressures.

"When most people think about reefs, they think of tropical shallow-water reefs like the beautiful Great Barrier Reef in Australia," added Stevenson. "But we have these incredible deep-water reefs in our own backyard in Canada. If we don't do our best to stand up for them, it will be like discovering a herd of dinosaurs and then immediately dropping dynamite on them."

Background:

The colossal reefs can grow to 19 metres in height and are built by larval sponges settling atop the fused dead skeletons of previous generations. In northern B.C. the reefs are found at depths of 90 to 300 metres, while in southern B.C., they can be found as shallow as 22 metres.

The sponges feed by pumping sea water through their delicate bodies, filtering almost 80 per cent of microbes and particles and expelling clean water.

It's estimated that the 19 known reefs in the Salish Sea can filter 100 billion litres of water every day, equivalent to one per cent of the total water volume in the Strait of Georgia and Howe Sound combined.

Researchers at the Francis Crick Institute have uncovered how cancer cells protect themselves from viruses that are harmful to tumours but not to healthy cells. These findings could lead to improved viral treatments for the disease.

In their study, published in Nature Cell Biology, the researchers identified a mechanism that protects cancer cells from oncolytic viruses, which preferentially infect and kill cancer cells.

These viruses are sometimes used as a treatment to destroy cancer cells and stimulate an immune response against the tumour. However, they only work in a minority of patients and the reasons whether they are effective or not are not yet fully understood.

The team examined the environment surrounding a tumour and how cancer cells interact with their neighbours, in particular, cancer-associated fibroblasts (CAFs), which researchers know play a significant role in cancer protection, growth and spread.

They found that when cancer cells are in direct contact with CAFs, this leads to inflammation that can alert the surrounding tissue, making it harder for viruses to invade and replicate within the cancer cell.

This protective inflammatory response occurs when cancer cells pass small amounts of cytoplasm, the fluid in their cells, through to the CAFs. This triggers the fibroblasts to signal to nearby cells to release cytokines, molecules that cause inflammation.*

Erik Sahai, paper author and group leader of the Tumour Cell Biology Laboratory at the Crick says: "This process only occurs when cancer cells and fibroblasts are in direct contact with each other. In healthy tissue, this type of inflammatory response would only happen during injury, as there is usually a membrane keeping them apart.

"This is an excellent example of the way cancer hijacks our body's protective mechanisms for its own gain."

Importantly, when the researchers blocked the signalling pathway in cell cultures and in tumours grown in the laboratory, they found that the cancer cells became more sensitive to oncolytic viruses.

They hope these findings may, in the future, help to develop a treatment that could modulate the inflammation and so help oncolytic viruses to more effectively target cancer cells.

Emma Milford, co-lead author and Phd student in the Tumour Cell Biology Laboratory at the Crick says: "If we can more fully understand how cancer cells protect themselves from oncolytic viruses and find effective ways to stop these protective mechanisms, these viruses could become a more powerful tool doctors can use to treat cancer. This research is an important, early step towards this."

Antonio Rullan, co-lead author and clinical research fellow in the Tumour Cell Biology Laboratory at the Crick adds: "These viruses prefer to target cancer cells over healthy cells, which has made them of interest for scientists over the last few decades. However, much more remains to be understood about how they interact with tumours and the immune system."

The researchers plan to continue this work and study exactly how the cytoplasm is transferred from one cell to another.

The Mesopelagic zone, or Twilight zone, contains the largest and least exploited fish reserves in the oceans. It is crucial for the sustainability of the oceans and for the elimination of carbon dioxide from the atmosphere and its storing in the deep oceans for centuries or more. Despite its importance in the balance of the oceans and the global carbon cycle, it is a little understood zone, physically, biochemically and ecologically. Faced with this lack of knowledge, there is the danger that there could be an increase in the demand for its resources by a continuously growing population means greater exploitation of this zone without first understanding the possible climatic consequences. The response of its ecosystems to climate change is still unknown, taking into account that temperature variations, acidification deoxygenation have a definite effect on the life of the zone.

Bearing this in mind, a group of international experts, in which the University of Seville participated, has just published an article in the prestigious review Nature in which they suggest responses to question such as how organisms live in the Twilight zone and how diverse they are; which organic processes transform and consume the zone's organic material; and how the organic material is carried into and out of it.

The mesopelagic zone or twilight zone refers to the ocean zone found between depths of approximately 200 and 1000 metres in depth. It is defined by the amount of light that it receives, so that the start of the mesopelagic zone is defined by where the depth where the light level reaches only 1% and the end by where the light stops. It is the zone found between the ocean surface and the abyssal zone. Estimations of the biomass of fish vary between a billion and 20 million tons, but it is not clear what fraction of the organisms are siphonophores (species related to jellyfish) and cephalopods (for example, squid).

In addition, this ecosystem plays a fundamental role in the maintaining of the growth of phytoplankton on the oceans' surfaces each spring. Forming part, by means of the so called biological pump of the global carbon cycle, which includes its storage in the ocean. However, "it is not known exactly how organic material is recycled in the twilight zone and how it returns to the surface to feed the phytoplankton and how much and how it crosses this zone of the ocean to be stored in the depths. In addition, climate change, which directly affects the oceans' temperature and oxygen levels, could change the way in which this biological pump works", indicates María Villa, University of Seville researcher and one of the authors of the study.

According to the experts, this zone is threatened by three main factors; the increase in demand for food by the ever- growing global population, the mining of the seabed in search of minerals and metals, which could increase the waste in the region; and, finally, climate change, which is altering the temperature, causing acidification and changing oxygen levels in the ocean, so that they might impact on life in the zone.