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As agriculture in the United States evolves, it's becoming more intensive and less complex. That means larger fields, more cropland and less crop diversity with fewer crops in rotation.

Ecological theory generally holds that diversity promotes stability in biological systems. Ashley Larsen, an assistant professor at UC Santa Barbara's Bren School of Environmental Science & Management, was curious how these tenets translate to agricultural landscapes, particularly with respect to crop pests.

Larsen and her colleague Frederik Noack, at the University of British Columbia, analyzed 13 years of data from Kern County, California -- which consistently tops lists of the nation's most valuable agricultural counties -- and discovered that less diverse croplands led to greater variability in pesticide use as well as to higher peak pesticide application. Their findings appear in the journal Nature Sustainability.

The idea that greater diversity stabilizes an ecosystem emerged around the 1940s, relatively early in the development of ecology as a field. The theory has encountered some skepticism throughout the years, and there's recently been a resurgence of interest in investigating this relationship.

Kern County provided a fantastic opportunity for the two researchers to study the phenomenon; in this case, how changes in crop and landscape diversity affect populations of crop pests.

"The U.S. has seen a shift toward larger agricultural enterprises," said Larsen. "So instead of small family farms we now have much bigger agricultural conglomerates." That has accompanied the trend of increasing field size and decreasing crop diversity. She suspects these all relate back to farmers taking advantage of the economy of scale.

Although Kern keeps extensive agricultural records, no one tracks the populations of pests, per se. This meant the researchers had to use a proxy: insecticide use. Only later did they appreciate how much this decision expanded the implications of their findings.

"Once you introduce insecticides into the study, then it's not just about diversity and stability in this ecological theory," Larsen said. "Now it has implications for environmental impacts and food security."

Larsen and Noack scoured the county records from 2005 through 2017 focusing on factors such as field size, as well as the amount and diversity of croplands. What they saw seemed to sync with their predictions. "We find increasing cropland in the landscape and larger fields generally increase the level and variability of pesticides, while crop diversity has the opposite effect," the authors wrote.

As field size increases, the area gets larger more quickly than the perimeter. This means that smaller fields have proportionally larger perimeters. And a larger perimeter may mean more spillover from nearby predators like birds, spiders and ladybugs that eat agricultural pests.

Smaller fields also create more peripheral habitat for predators and competitors that can keep pest populations under control. And since the center of a smaller field is closer to the edge, the benefits of peripheral land in reducing pests extends proportionally farther into the small fields.

Landscapes with diverse crops and land covers also correlated with reduced pesticide variability and overall use. Different crops in close proximity foster a variety of different pests. Though this may sound bad, it actually means that no single species will be able to multiply unimpeded.

"If agriculture is very simplified, there's little stopping a big outbreak of one type of pest," Larsen said. "If you're a pest in a monoculture, and that's your host crop, you have almost unlimited food resources."

Larsen and Noack's findings immediately suggest strategies for increasing food production while minimizing the impact of pesticides on human health and the environment. The study could not only help farmers make more informed decisions about field size and crop diversity, but also guide policy with the aim of decreasing insecticide use.

The Department of Agriculture's Farm Service Agency oversees several conservation-related programs addressing a number of different issues, including habitat preservation. Larsen suggests that tailoring these efforts to the nuances of different crop types could provide even greater benefits.

What's more, these voluntary programs currently focus on efforts by individual farmers. "Based on our results, we need to think, ideally, at more of a landscape scale," Larsen said.

It's difficult to untangle confounding factors in the relationship between land use and insecticide use. For instance, farmers put a lot of thought into how they plant their crops, potentially planting more valuable crops in larger fields or less diverse areas, Larsen explained. At the same time, farmers invest more in pest control, including chemical pesticides, for these high value crops, making it hard to tease apart the effect of landscape characteristics from these difficult-to-observe decisions.

The authors addressed these concerns using a combination of techniques borrowed from the economics literature in an attempt to establish a more causal understanding of the relationship between landscape characteristics and insecticide use.

California produces a diverse array of high-valued crops, from grapes and berries to almonds and citrus. This contrasts with regions like the Midwest and its amber waves of grain. Fields of cereals, like corn and wheat, can extend across vast swaths of the American heartland in virtual monocultures. What's more, these crops aren't nearly as valuable on a per-acre basis.

All these factors influence the risks associated with pests and the economics of pesticide application. "So it's hard to say whether these results would translate well to areas with very low value cropland because the incentives to really scout your pests might be much lower," Larsen said.

She has continued to investigate the effects of land use on agricultural production at both regional and national scales. In a recent paper published in the journal Landscape Ecology, she evaluated how both changing land use and climate may impact insecticide use throughout the U.S. While both are expected to increase future insecticide use, crop composition and farm characteristics are highly influential.

Unfortunately, national data does not provide the same high-resolution information as Kern County, Larsen explained. She plans to continue her work to bridge the detail and scale gap to better understand how land use impacts agricultural pests and pesticide use.

Lessons on healthy feeding practices delivered to young mothers through a brief home-visiting intervention put Native American infants on a healthier growth trajectory, lowering their risks for obesity, according to a study from researchers at the Johns Hopkins Center for American Indian Health at the Bloomberg School of Public Health.

Prior research suggests that adult obesity, which is linked to heart disease and diabetes, can be programmed early in life. Native Americans have particularly high rates of obesity starting in childhood--it is estimated that more than one-third of Native American 2- to 5-year-olds are overweight or obese.

In the study, published November 9 in JAMA Pediatrics, Native American home visitors delivered six 45-minute nutrition lessons to mothers of infants on the Navajo Nation. The intervention, conducted when infants were 3 to 6 months old, taught mothers to adopt optimal feeding practices for their babies, including avoiding sugar-sweetened beverages.

The researchers found that on average the 68 mothers in the home-visiting program had better feeding practices and their babies had healthier weights during the first year of life, compared to the same sized control group.

"This is the first home-visiting intervention, tested through a randomized controlled trial, designed in partnership with Native American communities that targets obesity in the first year of life with positive impacts on healthy growth," says study first author Summer Rosenstock, PhD, an assistant scientist in the Bloomberg School's Department of International Health and a member of the Center for American Indian Health at the Bloomberg School.

The program, known as Family Spirit Nurture, is a six-lesson curriculum built on a federally endorsed home-visiting program designed by the Center for American Indian Health to improve maternal and child outcomes for Native American families.

"Native American children suffer the highest rates of early childhood obesity in the U.S.," says study co-author Leonela Nelson, a Navajo tribal member and program supervisor for the Center for American Indian Health at the research site on the Navajo Nation in Shiprock, NM. "The Family Spirit Nurture program showed that local Native home visitors working to educate and support moms can have positive effects on infant feeding and growth during the first year of life."

In the study, the Native American family health coaches delivered the Family Spirit Nurture intervention to 68 mothers on the Navajo Nation in Shiprock, New Mexico, and surrounding communities, while their infants were between 3 and 6 months old. A control group of 66 mothers in the same community received, during the same age interval for their infants, three lessons on injury prevention under the original Family Spirit home-visiting program.

The researchers found that the Family Spirit Nurture intervention helped mothers in the intervention group score significantly higher on measures of responsive feeding--the practice of reading and responding to babies' cues for hunger. "It is important that parents don't use food to soothe babies when they are fussing for sleep, a diaper change, or other discomforts besides hunger," says Rosenstock.

Similarly, mothers in the intervention group reported significantly less feeding of sugar-sweetened beverages to their children at 9 and 12 months of age, compared to control group mothers.

The researchers also analyzed data from medical charts on the infants' weights and other vital measures from birth to 12 months and found that infants in the intervention group, compared to those in the control group, had healthier weights on average for their height, age, and sex up to 12 months of age--according to a measure called the standardized body-mass index, or zBMI. In addition, at 12 months, infants in the control group on average were above the threshold for overweight, according to their zBMI measures, while intervention infants were not.

For Rosenstock and her colleagues, the results from this initial study suggest that the Family Spirit Nurture intervention, implemented by Native American home visitors, may be an effective strategy in Native American communities for improving mothers' infant feeding practices and supporting infants' healthier growth trajectories. They note that other Family Spirit interventions, not relating to childhood obesity, are already accepted and conducted in more than 130 tribal communities across 21 states, providing a platform to disseminate this new six-lesson module.

"The home visitors incorporate cultural teachings and practices into the lessons to support moms' connectedness to their Native culture. Connections to our culture promote further well-being," says Nelson.

The researchers continue to investigate how well interventions like the one tested in this study can reduce childhood obesity, through age 2.

"There is evidence that the first 24 months of life is a really critical time period to intervene to put infants on healthier growth trajectories and reduce their long-term risk for obesity," Rosenstock says.

A genetic disposition that plays a role in the development of the heart in the embryo also appears to play a key role in the human immune system. This is shown by a recent study led by the University of Bonn (Germany). When the gene is not active enough, the immune defense system undergoes characteristic changes, causing it to lose its effectiveness. Doctors speak of an aging immune system, as a similar effect can often be observed in older people. In the medium term, the results may contribute to reduce these age-related losses. The study is published in the journal Nature Immunology.

The gene with the cryptic abbreviation CRELD1 has so far been a mystery to science. It was known to play an important role in the development of the heart in the embryo. However, CRELD1 remains active after birth: Studies show that it is regularly produced in practically all cells of the body. For what purpose, however, was previously completely unknown.

The Bonn researchers used a novel approach to answer this question. Nowadays, scientific studies with human participants often include so-called transcriptome analyses. By these means, one can determine which genes are active to what extent in the respective test subjects. Researchers are also increasingly making the data they obtain available to colleagues, who can then use it to work on completely different matters. "And this is exactly what we did in our study," says Dr. Anna Aschenbrenner from the LIMES Institute at the University of Bonn and member of the ImmunoSensation² Cluster of Excellence.

Aschenbrenner is doing her habilitation in the Genomics and Immunoregulation team of Prof. Dr. Joachim Schultze. Together with her colleagues, she combined transcriptome data from three different studies. "This provided us with information on the activity of the genetic material, including the CRELD1 gene, of a total of 4,500 test subjects," she explains. "In addition, the data for these participants also included information on certain immunological parameters, such as the number of different immune cells in their blood."

CRELD1 is less active in some people

The researchers discovered a surprising correlation when analyzing this information: The 4,500 analyzed test subjects included some in whom the CRELD1 gene was significantly less active for some reason. Interestingly, the blood of these donors was found to contain only very few of the so-called T cells. These cells play an important role in fighting infections; some of them detect virus-infected cells and kill them before they can infect other cells.

The researchers further investigated this relationship in mouse experiments. The results showed that the genetic loss of the Creld1 gene was indeed the cause for the loss of T cells. T cells lacking the Creld1 gene largely lose their ability to propagate and die earlier. "We see similar changes in people with an 'aged' immune system," Aschenbrenner stresses. This phenomenon, also called immunosenescence, is mainly observed in older people. Those affected are much more susceptible to infections, as currently discussed in the context of COVID-19, but possibly also to age-related diseases such as cancer or Alzheimer's. It is known that the activity of numerous genes in the blood is altered in a characteristic way, which experts also refer to as an immunological aging signature. "We found precisely this signature among participants with low CRELD1 activity," says Aschenbrenner.

Centenarians with a young immune system

Surprisingly, some people's immune system ages much faster than others. For instance, there are centenarians who, immunologically speaking, are several decades younger. With others, the power of the body's own disease defense system already diminishes significantly in the middle of life. The researchers now hope that CRELD1 will provide them with a key to better understand the causes of immunological aging. "The long-term goal is to slow down or halt this process," explains Aschenbrenner. "This could perhaps significantly reduce the risk of illness in seniors."

Female banded mongooses lead their groups into fights then try to mate with enemy males in the chaos of battle, new research shows.

Mongooses rarely leave the group into which they are born, meaning members are usually genetically related - and the new study reveals how females get round the problem of inbreeding.

The research team - led by the University of Exeter and the University of Cambridge - say females start fights for the genetic benefits of finding unrelated males.

Meanwhile, males bear the costs of these fights, in which injuries and deaths are common.

The researchers say "exploitative leadership" of this kind, which is also seen in human warfare, leads to frequent and damaging conflicts.

"We've known for some time that banded mongoose groups often engage in violent battles - and now we know why," said Professor Michael Cant, of the Centre for Ecology and Conservation on Exeter's Penryn Campus in Cornwall.

"Females start fights between groups to gain genetic benefits from mating with outsiders, while the males within their group - and the group as a whole - pay the costs.

"A classic explanation for warfare in human societies is leadership by exploitative individuals who reap the benefits of conflict while avoiding the costs.

"In this study, we show that leadership of this kind can also explain the evolution of severe collective violence in certain animal societies."

Dr Faye Thompson, from the University of Exeter, added: "We tested our model using long-term data from wild banded mongooses in Uganda.

"The findings do not fit a heroic model of leadership, in which leaders contribute most to aggression and bear greatest costs, but rather an exploitative model, in which the initiators of conflict expose others to greater risks while contributing little to fighting themselves."

The findings suggest that "decoupling" leaders from the costs of their choices "amplifies the destructive nature of intergroup conflict".

Professor Rufus Johnstone of the University of Cambridge, who led the theoretical research, said: "Exploitative leadership in banded mongooses helps to explain why intergroup violence is so costly in this species compared to other animals.

"The mortality costs involved are similar to those seen in a handful of the most warlike mammals, including lions, chimpanzees and of course humans."

UNIVERSITY PARK, Pa. -- Sensors that monitor a patient's condition during and after medical procedures can be expensive, uncomfortable and even dangerous. Now, an international team of researchers has designed a highly sensitive flexible gas sensor that can be implanted in the body -- and, after it's no longer needed, safely biodegrade into materials that are absorbed by the body.

In a study, the researchers reported they designed a flexible and implantable sensor that can monitor various forms of nitric oxide (NO) and nitrogen dioxide (NO2) gas in the body. Monitoring these types of gases is important because they can play either a beneficial or, sometimes, harmful role in human health, according to Huanyu "Larry" Cheng, Dorothy Quiggle Career Development Professor in the Department of Engineering Science and Mechanics and an affiliate of the Institute for Computational and Data Sciences.

Nitric oxide, for example, which is produced naturally in the human body, plays an important role in health because it relaxes or widens blood vessels to enhance blood flow, allowing oxygen and nutrients to circulate through the body. On the other hand, exposure to nitrogen dioxide from the environment is linked to the progression of conditions such as chronic obstructive pulmonary disease, said Cheng, who is also affiliated with the Materials Research Institute. Nitric oxide is highly reactive and can be transformed into nitrogen dioxide when exposed to oxygen.

The team, which reports their findings in the current issue of NPG Asia Materials, available online now, added a twist to their sensor design by making it from materials that are not just implantable, flexible and stretchable, but also biodegradable. While current devices are used outside of the body to monitor gas levels, Cheng said they are bulky and potentially not as accurate as an implantable device. Implantable devices, however, need to be removed, which could mean another operation. The researchers investigated a design that does not need to be removed.

"Let's say you have a cardiac surgical operation, the monitor outside of the body might not be sufficient to detect the gas," said Cheng. "It might be much more beneficial to monitor the gas levels from the heart surface, or from those internal organs. This gas sensor is implantable, and biodegradable, as well, which is another research direction we've been working on. If the patient fully recovers from a surgical operation, they don't need the device any longer, which makes biodegradable devices useful."

According to the researchers, all of the components are biodegradable in water or in bodily fluids, but remain functional enough to capture the information on the gas levels. In this case, the researchers made the device's conductors -- the elements that conduct electricity -- out of magnesium, and for the functional materials, they used silicon, which is also highly sensitive to nitric oxide.

The body can safely absorb all of the materials used in the device. An added benefit of the design is that the materials dissolve at a slow enough pace that would allow the sensors to function in the body during a patient's recovery period.

"Silicon is unique -- it's the building block for modern electronics and people consider it to be super-stable," said Cheng. "Silicon has been shown to be biodegradable, as well. It can dissolve in a really slow manner, at about one to two nanometers a day, depending on the environment."

According to the researchers, the sensor was tested in humid conditions and aqueous solutions to show that it could stably perform in the harsh conditions of the body.

The team used computational resources of ICDS's Roar supercomputer to create the computer simulations that can calculate extremely small changes caused by slight changes of shape, or deformations, of the material.

"We base the measurement on resistance, which can change based on the gas absorption, but it can also be changed due to the deformation," said Cheng. "So, if we deform the sensor on the skin surface, that will cause a large force and a large change in resistance and we would have no idea whether the gas' performance is from the deformation, or the exposed environment."

The researchers say future work could look at designing integrated systems that could monitor other bodily functions for healthy aging and various disease applications.

Abu Dhabi - One critical barrier in efforts to control the COVID-19 pandemic has been the relatively high false-negative rate of the most commonly-used Reverse Transcription Polymerase Chain Reaction (RT-PCR) testing methods.

Often, these methods are not able to detect lower viral loads, which are typically present in asymptomatic individuals but below the limit of detection (LoD) of standard one- or two-step RT-PCR methods. Researchers from NYU Abu Dhabi's Biology Program and Center for Genomics and Systems Biology (CGSB) have implemented a new three-step testing approach that promises to significantly - and cost-effectively -- improve testing accuracy.

Rather than combining the RT and qPCR reactions, the NYUAD researchers, led by Professor of Biology at NYU and NYUAD Kris Gunsalus and Assistant Professor of Biology at NYUAD Youssef Idaghdour employed a technique involving sequential RT, cDNA preamplification, and qPCR, using a microfluidics platform.

The researchers demonstrated reliable ultra-sensitive and quantitative detection of low SARS-CoV-2 viral loads (less than one copy/microliter) using synthetic viral RNA, clinical nasopharyngeal swab samples and saliva samples, including samples previously diagnosed as negative by clinical diagnostic testing. Their findings, reported in the journal Processes are that this microfluidic RT-PCR assay is a sensitive, quantitative, and cost-effective detection strategy which could markedly reduce the false negative rate of clinical diagnostic tests - a potentially valuable tool in SARS-CoV-2 active screening and early detection programs.

"By adding a pre-amplification step and using microfluidic technology, we have demonstrated that this sensitive detection method can detect low viral loads, which is critical to enabling the most effective public health responses to the COVID-19 pandemic," said Idaghdour. "Our three-step approach can significantly reduce the false negative rate of standard RT-PCR-based diagnostic tests for SARS-CoV2 and other viral infections. This would allow public health officials to more readily identify and trace asymptomatic individuals, enhance the accuracy of air and environmental sampling for SARS-CoV-2, expand accurate detection to saliva testing and help curtail the spread of the virus."

About NYU Abu Dhabi

NYU Abu Dhabi is the first comprehensive liberal arts and science campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly-selective liberal arts, engineering and science curriculum with a world center for advanced research and scholarship enabling its students to succeed in an increasingly interdependent world and advance cooperation and progress on humanity's shared challenges. NYU Abu Dhabi's high-achieving students have come from more than 115 nations and speak over 115 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.

Rochester Institute of Technology scientists have developed new simulations of black holes with widely varying masses merging that could help power the next generation of gravitational wave detectors. RIT Professor Carlos Lousto and Research Associate James Healy from RIT's School of Mathematical Sciences outline these record-breaking simulations in a new Physical Review Letters paper.

As scientists develop more advanced detectors, such as the Laser Interferometer Space Antenna (LISA), they will need more sophisticated simulations to compare the signals they receive with. The simulations calculate properties about the merged black holes including the final mass, spin, and recoil velocity, as well as peak frequency, amplitude, and luminosity of the gravitational waveforms the mergers produce.

"Right now, we can only observe black holes of comparable masses because they are bright and generate a lot of radiation," said Lousto. "We know there should be black holes of very different masses that we don't have access to now through current technology and we will need these third generational detectors to find them. In order for us to confirm that we are observing holes of these different masses, we need these theoretical predictions and that's what we are providing with these simulations."

The scientists from RIT's Center for Computational Relativity and Gravitation created a series of simulations showing what happens when black holes of increasingly disparate masses--up to a record-breaking ratio of 128:1--orbit 13 times and merge.

"From a computational point of view, it really is testing the limits of our method to solve Einstein's general relativity equations on supercomputers," said Lousto. "It pushes to the point that no other group in the world has been able to come close to. Technically, it's very difficult to handle two different objects like two black holes, in this case one is 128 times larger than the other."

CLEMSON, South Carolina - Groundbreaking science is often the result of true collaboration, with researchers in a variety of fields, viewpoints and experiences coming together in a unique way. One such effort by Clemson University researchers has led to a discovery that could change the way the science of thermoelectrics moves forward.

Graduate research assistant Prakash Parajuli; research assistant professor Sriparna Bhattacharya; and Clemson Nanomaterials Institute (CNI) Founding Director Apparao Rao (all members of CNI in the College of Science's Department of Physics and Astronomy) worked with an international team of scientists to examine a highly efficient thermoelectric material in a new way - by using light.

Their research has been published in the journal Advanced Science and is titled "High zT and its origin in Sb-doped GeTe single crystals."

"Thermoelectric materials convert heat energy into useful electric energy; therefore, there is a lot of interest in materials that can convert it most efficiently," Parajuli said

Bhattacharya explained that the key to measuring progress in the field is the figure of merit, noted as zT, which is highly dependent on the property of thermoelectric materials. "Many thermoelectric materials exhibit a zT of 1-1.5, which also depends on the temperature of the thermoelectric material. Only recently have materials with a zT of 2 or higher have been reported."

"This begs the question, how many more such materials can we find, and what is the fundamental science that is new here through which a zT greater than 2 can be achieved?" Rao added. "Basic research is the seed from which applied research grows, and to stay at the forefront in thermoelectrics we teamed up with professor Yang Yuan Chen's team at the Academia Sinica, Taiwan."

Chen and Rao's teams focused on Germanium Telluride (GeTe), a single crystal material.

"GeTe is of interest, but plain GeTe without any doping does not show exciting properties," Bhattacharya said. "But once we add a little bit of antimony to it, it does show good electronic properties, as well as very low thermal conductivity."

While others have reported GeTe-based materials with high zT, these were polycrystalline materials. Polycrystals have boundaries among the many small crystals of which they are formed. While such boundaries favorably impede heat transfer, they mask the origin of fundamental processes that lead to high zT.

"Here, we had pure and doped GeTe single crystals whose thermoelectric properties have not been reported," Bhattacharya said. "Therefore, we were able to evaluate the intrinsic properties of these materials that would otherwise be difficult to decipher in the presence of competing processes. This may be the first GeTe crystal with antimony doping that showed these unique properties - mainly the ultra-low thermal conductivity."

This low thermal conductivity came as a surprise, since the material's simple crystalline structure should allow for heat to flow easily throughout the crystal.

"Electrons carry the heat and electricity, so if you block the electrons, you have no electricity," Parajuli said. "Hence, the key is to block the flow of heat by the quantized lattice vibrations known as phonons, while allowing electrons to flow."

Doping GeTe with the right amount of antimony can maximize electron flow and minimize heat flow. This study found that the presence of 8 antimony atoms for every 100 GeTe gives rise to a new set of phonons, which effectively reduce heat flow that was confirmed both experimentally and theoretically.

The team, along with collaborators who grew the crystals, performed electronic and thermal transport measurements in addition to density functional theory calculations to find this mechanism in two ways: first, through modeling, using the thermal conductivity data; second, through Raman spectroscopy, which probes the phonons within a material.

"This is a totally new angle for thermoelectric research," Rao said. "We are sort of pioneers in that way - decoding thermal conductivity in thermoelectrics with light. What we found using light agreed well with what was found through thermal transport measurements. Future research in thermoelectrics should use light - it's a very powerful nondestructive method to elucidate heat transport in thermoelectrics. You shine light on the sample, and collect information. You aren't destroying the sample."

Rao said that the collaborators' wide range of expertise was key to their success. The group included Fengjiao Liu, a former Ph.D. student at CNI; Rahul Rao, Research Physical Scientist at the ?Air Force Research Laboratory, Wright-Patterson Air Force Base; and Oliver Rancu, a high school student at the South Carolina Governor's School for Science and Mathematics who worked with the team through Clemson's SPRI (Summer Program for Research Interns) program. Because of the pandemic, the team worked with Rancu via Zoom, guiding him with some of Parajuli's calculations using an alternate Matlab code.

"I am so very grateful for the opportunity to work with the CNI team members this summer," said Rancu, who hails from Anderson, South Carolina. "I have learned so many things about both physics and the research experience in general. It truly was priceless, and this research publication is just another addition to an already fantastic experience."

"I was very impressed by Oliver," Parajuli added. "He caught on quickly with the necessary framework for the theory."

DALLAS, Nov. 9, 2020 -- The more secondhand tobacco smoke children breathe at home while growing up, the higher chance they have of developing markers of decreased heart function as adults, according to preliminary research to be presented at the American Heart Association's Scientific Sessions 2020. The meeting will be held virtually, Friday, November 13 - Tuesday, November 17, 2020, and is a premier global exchange of the latest scientific advancements, research and evidence-based clinical practice updates in cardiovascular science for health care worldwide.

"We already know from previous studies that children exposed to secondhand smoke are more likely to have structural differences in their vascular systems as adults, such as thicker blood vessel walls and a higher risk of plaque buildup in the arteries," said Chigoze Ezegbe, M.B.B.S., M.P.H., lead author of the study and a Ph.D. candidate at the Menzies Institute for Medical Research at the University of Tasmania in Hobart, Australia. "In this study, we wanted to understand the impact of prolonged secondhand smoke exposure during childhood on heart function in adulthood."

The investigators examined the health records of more than 1,100 adults (average age 45 years, 52% female) who are participants in the ongoing Childhood Determinants of Adult Health study, an Australia-wide research project initiated in 1985 that investigates the importance of childhood factors in the later development of risk factors for heart disease and stroke. About half (54%) of the participants were exposed to secondhand smoking at home during childhood. The participants' most recent evaluation was between 2014 and 2019, 34 years after they entered the study as schoolchildren.

The severity of childhood smoking exposure was calculated three ways: the number of smokers in the home; the number of years each child was exposed to tobacco smoking by household members; and the severity of exposure index - whether a child was said to be exposed in the home never, sometimes or always.

In the adult evaluation, ultrasound imaging was used to measure the global longitudinal strain (GLS) of the left ventricle, the heart's major pumping chamber. GLS indicates how much the muscles of the left ventricle shorten as they help squeeze blood out of the heart, compared with the muscles' resting length between heartbeats.

"The GLS can show early changes in the ability of the heart to contract properly and that can provide information on the risk of heart disease," Ezegbe said. "Previous research shows that each 1% decrease in GLS has been associated with a 12% higher risk of cardiovascular morbidity and mortality in a low-risk, general population."

Researchers found that adult global longitudinal strain declined significantly:

With each additional member of the child's household who smoked, which ranged from 0-5 smokers;

With more years of childhood exposure to tobacco smoke; and

With higher scores on the childhood severity of exposure index.

"These findings extend our previous work on the structure of the vascular system to suggest that how the heart functions is also affected when exposed to passive smoke," said Seana Gall, Ph.D., senior author of the study and associate professor of cardiovascular and respiratory health and disease at the Menzies Institute for Medical Research at the University of Tasmania.

The researchers are currently examining other cardiovascular effects of secondhand smoke exposure, including alterations in blood pressure and plaque buildup in arteries.

"Recognizing that adult cardiovascular health is influenced by factors across the lifespan including childhood may be important in advocacy initiatives and in implementing interventions to reduce the risks. These could include messages and programs that can help prompt parents to protect their children from tobacco smoke and the associated long-term health risks," Ezegbe said.

The study is limited by not having information on participants' prenatal exposure to smoking or on the number of cigarettes smoked around them. This information would have been valuable to determine if there was any dose-response effect to secondhand smoke.

"Children, especially young children, are typically exposed to tobacco smoke involuntarily, with little choice, yet it clearly can affect their health," said Rose Marie Robertson, M.D., FAHA, deputy chief science and medical officer of the American Heart Association and co-director of the Association's Tobacco Center of Regulatory Science. "This study confirms that children should be protected from passive smoking -- because it negatively impacts their health during childhood, and it leads to long-term health consequences in adulthood."

These findings from Australia should be generalizable to any United States population with a high level of childhood exposure to secondhand smoke, according to the researchers.

Durham, NC - A new study released today in STEM CELLS might just have solved the mystery behind why mesenchymal stem cells (MSCs) continue to suppress inflammation in the body long after the MSCs are cleared from the system. The findings, by researchers at Duke University (Durham, N.C.), could help overcome a critical barrier to MSCs being considered a reliable option when developing treatments for inflammatory diseases ranging from COVID-19 and cancer, to allergies, arthritis and more.

MSCs are stem cells that can be isolated from bone marrow, adipose and other tissue sources. Their ability to differentiate into a variety of cell types, along with their capability to self-renew, repair and heal, make them attractive candidates for therapeutic use.

However, there's a drawback, researchers say.

"While MSCs are widely used in clinical trials due to their ability to modulate inflammation, their success over the past 25 years has been varied - something that is likely a result of us not being able to totally understand how they work," said Anthony Filiano, Ph.D. He and Hyunjung Min, Ph.D., in Duke's Marcus Center for Cellular Cures, were co-leaders of the current study.

The ability for MSCs to suppress T cells is well documented in the lab, but little is known how they function in the body. "What we do know," Dr. Filiano continued, "is that after MSCs are injected into the body, they travel to the lungs and other tissues and then are rapidly cleared. Despite this, MSCs suppress the inflammatory response long-term. If the reason behind why and how this is happening can be determined, the information could be very helpful in developing new treatments for a variety of inflammatory diseases."

In search of an answer, the Duke team injected human cord tissue-derived MSCs (hCT-MSCs) into mice with induced lung inflammation. Twenty-four hours later when the mouse lungs were analyzed, "We found that pieces of the MSCs had been engulfed by monocytes and macrophages (types of disease-fighting cells), in effect clearing them from the animals' systems," Dr. Min reported. "We also noted long-term transcription changes in the cells that ate pieces of MSCs suppressed the activation of T cells." (Transcription is the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA.)

Next, using a combination of computational and pharmacological approaches, the researchers identified potential receptors on monocytes and macrophages that mediated their interactions with the hCT-MSCs and blocked interaction with a pharmacological inhibitor. They also identified a key cytoplasmic organelle in hCT-MSCs necessary to reprogram the monocytes and macrophages.

"Our results shed light on how MSCs can modulate the inflammatory response without long-term engraftment using a previously undescribed form of cell communication," said Dr. Filiano, "and explain how MSCs have extended beneficial effects on the body despite being cleared just hours after administration."

Dr. Jan Nolta, Editor-in-Chief of STEM CELLS, said, "this study, which determines a mechanism by which the effects of MSCs on immune modulation are extended after the cells themselves are physically cleared, brings clarity to an longstanding and important question in the field. We congratulate the authors for this important report."

The capacity of the Amazon forest to store carbon in a changing climate will ultimately be determined by how fast trees die - and what kills them. Now, a huge new study has unravelled what factors control tree mortality rates in Amazon forests and helps to explain why tree mortality is increasing across the Amazon basin.

This large analysis found that the mean growth rate of the tree species is the main risk factor behind Amazon tree death, with faster-growing trees dying off at a younger age. These findings have important consequences for our understanding of the future of these forests. Climate change tends to select fast-growing species. If the forests selected by climate change are more likely die younger, they will also store less carbon.

The study, co-led by the Universities of Birmingham and Leeds in collaboration with more than 100 scientists, is the first large scale analysis of the causes of tree death in the Amazon and uses long-term records gathered by the international RAINFOR network.

The results published in Nature Communications, show that species-level growth rates are a key risk factor for tree mortality.

"Understanding the main drivers of tree death allows us to better predict and plan for future trends - but this is a huge undertaking as there are more than 15,000 different tree species in the Amazon," said lead author Dr Adriane Esquivel-Muelbert, of the Birmingham Institute of Forest Research.

Dr David Galbraith, from the University of Leeds added "We found a strong tendency for faster-growing species to die more, meaning they have shorter life spans. While climate change has provided favourable conditions for these species, because they also die more quickly the carbon sequestration service provided by Amazon trees is declining."

Tree mortality is a rare event so to truly understand it requires huge amounts of data. The RAINFOR network has assembled more than 30 years of contributions from more than 100 scientists. It includes records from 189 one-hectare plots, each visited and monitored on average every 3 years. Each visit, researchers measure all trees above 10cm in diameter as well as the condition of every tree.

In total more than 124,000 living trees were followed, and 18,000 tree deaths recorded and analysed. When trees die, the researcher follows a fixed protocol to unravel the actual cause of death. "This involves detailed, forensic work and amounts to a massive 'CSI Amazon' effort conducted by skilled investigators from a dozen nations", noted Prof. Oliver Phillips, from the University of Leeds.

Dr Beatriz Marimon, from UNEMAT, who coordinates multiple plots in central Brazil added: "Now that we can see more clearly what is going on across the whole forest, there are clear opportunities for action. We find that drought is also driving tree death, but so far only in the South of the Amazon. What is happening here should serve as an early warning system as we need to prevent the same fate overtaking trees elsewhere."

Cigarette smoking remains a leading preventable cause of morbidity and mortality in the United States. And while adolescent cigarette smoking has declined over the past several decades, e-cigarette use presents a new risk for nicotine use disorder. a new study, published Nov. 9 in the journal Pediatrics, finds that e-cigarette use is associated with a higher risk of cigarette smoking among adolescents who had no prior intention of taking up conventional smoking. These findings have strong implications for practice and policy, researches say.

"Research is showing us that adolescent e-cigarette users who progress to cigarette smoking are not simply those who would have ended up smoking cigarette anyway," says Olusegun Owotomo, M.D., Ph.D., M.P.H., the study's lead author and a pediatric resident at Children's National Hospital. "Our study shows that e-cigarettes can predispose adolescents to cigarette smoking, even when they have no prior intentions to do so."

In one of the first theory-guided nationally representative studies to identify which adolescent e-cigarette users are at most risk of progressing to cigarette smoking, Researchers looked at data of more than 8,000 U.S. adolescents, ages 12-17, who had never smoked. The data was collected by the Population Assessment of Tobacco and Health (PATH) study, an NIH and FDA collaborative nationally representative prospective cohort study of tobacco use, from 2014-2016. Among adolescents who did not intend to smoke cigarettes in the future, those who used e-cigarettes were more than four times more likely to start smoking cigarettes one year later compared to those who did not use e-cigarettes.

E-cigarette use constitutes a relatively new risk factor for nicotine use disorder among U.S. adolescents. A 2019 study from the Centers for Diseases Control and Prevention found that 28% of high school students and 11% of middle school students were current e-cigarette users. With the recent emergence of newer and potentially highly addictive e-cigarette products, adolescents who use e-cigarettes are at increased risk of developing nicotine use disorder and progressing to smoke conventional cigarettes.

"Abstinence from e-cigarettes can protect teens from becoming future smokers and should be framed as a smoking prevention strategy by all concerned stakeholders," says Dr. Owotomo. "Pediatricians are best positioned to educate patients and families on the clinical and psychosocial consequences of e-cigarette use and should support education campaigns and advocacy efforts geared to discourage adolescent e-cigarette use."

Researchers from the Institut national de la recherche scientifique (INRS) have shown that nanoparticles could be used to deliver drugs to the brain to treat neurodegenerative diseases.

The blood-brain barrier is the main obstacle in treating neurodegenerative diseases such as Alzheimer and Parkinson. According to a recent study conducted by Jean-Michel Rabanel, a postdoctoral researcher under the supervision of Professor Charles Ramassamy, nanoparticles with specific properties could cross this barrier and be captured by neuronal cells. Researchers are confident that these results will open important prospects for releasing drugs directly to the brain. This breakthrough finding would enable improved treatment for neurodegenerative diseases affecting more than 565,000 Canadians, including 141,000 Quebecers.

"The blood-brain barrier filters out harmful substances to prevent them from freely reaching the brain. But this same barrier also blocks the passage of drugs," explains the pharmacologist Charles Ramassamy. Typically, high doses are required to get a small amount of the drug into the brain. What remains in the bloodstream has significant side effects. Often, this discomfort leads the patient to stop the treatment. ?The use of nanoparticles, which encapsulate the drugs, would result in fewer collateral side effects while increasing brain efficiency.?

Efficient on an animal model

To prove the effectiveness of this method, the research team first tested it on cultured cells, then on zebrafish. "This species offers several advantages. Its blood-brain barrier is similar to that of humans and its transparent skin makes it possible to see nanoparticles' distribution almost in real time," says Professor Ramassamy, Chairholder of the Louise and André Charron Research Chair on Alzheimer's disease, from the Fondation Armand-Frappier.

Using in vivo tests, researchers were able to observe the crossing of the blood-brain barrier. They also confirmed the absence of toxicity in the library of selected nanoparticles. "We made the particles with polylactic acid (PLA), a biocompatible material that is easily eliminated by the body. A layer of polyethylene glycol (PEG) covers these nanoparticles and makes them invisible to the immune system, so they can longer circulate in the bloodstream," he explains. After several years of research on effective and safe nanoparticles, the research team will continue laboratory testing, targeting the delivery of active ingredients to other animal models with ultimate clinical applications.

WINSTON-SALEM, NC, NOVEMBER, 2020 -- Wake Forest Institute for Regenerative Medicine scientists (WFIRM) have developed a method to bioprint a type of cartilage that could someday help restore knee function damaged by arthritis or injury.

This cartilage, known as fibrocartilage, helps connect tendons or ligaments or bones and is primarily found in the meniscus in the knee. The meniscus is the tough, rubbery cartilage that acts as a shock absorber in the knee joint. Degeneration of the meniscus tissue affects millions of patients and arthroscopic partial meniscectomy is one of the most common orthopedic operations performed. Besides surgery, there is a lack of available treatment options.

In this latest proof-of-concept strategy, the scientists have been able to 3D bioprint a hybrid tissue construct for cartilage regeneration by printing two specialized bioinks - hydrogels that contain the cells - together to create a new formulation that provides a cell-friendly microenvironment and structural integrity. This work is done with the Integrated Tissue and Organ Printing System, a 3D bioprinter that was developed by WFIRM researchers over a 14-year period. The system deposits both biodegradable, plastic-like materials to form the tissue "shape" and bioinks that contain the cells to build new tissues and organs.

"In this study, we have been able to produce a highly elastic hybrid construct for advanced fibrocartilaginous regeneration," said Sang Jin Lee, Ph.D, associate professor at WFIRM and author of the paper recently published by Chemistry of Materials journal. "The results demonstrate that this bioprinted construct offers a versatile and promising alternative for the production of this type of tissue."

For the study, Lee and the WFIRM research team tested various formulations and measured response to applied forces or stresses, the swelling ratio and the material strength and flexibility. One provided the proper cellular microenvironment to maintain the cells and helping them grow while the other bioink offered excellent biomechanical behavior and structural integrity. The final formula of the two bioinks used were co-printed layer by layer to create a mesh-like pattern. The constructs were implanted into a small animal model for observation for 10 weeks and evaluated at intermittent time periods, showing proper function.

"A larger preclinical study will be needed to further examine the body's response and the functional recovery of the joint with use of this regenerative medicine treatment," said James Yoo, MD, PhD, professor at WFIRM.

"We have such a need for effective treatments and therapies to help patients deal with degenerative joint problems, especially the knee," said Anthony Atala, MD, director of WFIRM. "This proof-of-concept study helps point our work in the right direction to someday be able to engineer this crucial tissue that is so important for patients."

Spending time in nature is believed to benefit people's mental health. However, new research suggests that giving people with existing mental health conditions formal 'green prescriptions', may undermine some of the benefits.

An international research team led by the University of Exeter and published in the journal Scientific Reports, investigated whether contact with nature has the potential to help people with mental health issues, such as depression and anxiety, to manage their symptoms. They found that nature is associated with a number of benefits for these individuals, but only if they chose to visit these places themselves.

The research team collected data from more than 18,000 people in 18 different countries, as part of the EU Horizons 2020 funded BlueHealth project. A key aim was to understand why people feel motivated to spend time in nature, how often they visit, and how social pressure influences their emotional experiences during visits.

The findings suggest that whilst pressure to spend time outdoors can encourage visits, it can also undermine the potential emotional and wellbeing benefits of contact with nature.

Common mental health issues are the leading cause of disability worldwide, affecting approximately 17% of the world's population each year. Although there is evidence that some people with these issues are using nature as part of their own symptom self-management, there was still much we didn't not know about how widespread this was, or whether more formal 'Green prescriptions' from medical professional to spend time in nature could aid management and potentially recovery.

The research team were surprised to find that people with depression were already visiting nature as frequently as people with no mental health issues, while people with anxiety were visiting significantly more often. On the whole, both groups also tended to feel happy and reported low anxiety during these visits.

However, the benefits of nature seem to be undermined when visits were not by choice. The more pressure people felt to visit nature by presumably well-meaning others, the less motivated people were and the more anxious they felt.

The research was led by Dr Michelle Tester-Jones, of the University of Exeter. She said: "These findings are consistent with wider research that suggests that urban natural environments provide spaces for people to relax and recover from stress. However, they also demonstrate that healthcare practitioners and loved ones should be sensitive when recommending time in nature for people who have depression and anxiety. It could be helpful to encourage them to spend more time in places that people already enjoy visiting; so they feel comfortable and can make the most of the experience."

The authors believe their paper provides evidence that careful techniques to discuss accessing nature as a means of self- or supported-management for people with mental health issues need to be integrated into these programmes if they are to offer clients the best support.

Dr Mathew White, of the University of Exeter and University of Vienna, who co-ordinated the international research team, added: "We had no idea just how much people with depression and anxiety were already using natural settings to help alleviate symptoms and manage their conditions. Our results provide even greater clarity about the value of these places to communities around the world, but also remind us that nature is no silver bullet and needs to be carefully integrated with existing treatment options."

Dr Ann Ojala, a research team member from the Natural Resources Institute Finland (Luke) said: "The results encourage further research in clinical settings. We need more information on this delicate balance between the intrinsic motivation and sometimes necessary encouragement from outside, as well as how nature visits could be integrated to mental health treatment."

Co-author Dr Greg Bratman, of the University of Washington, said: "The results highlighted the importance of taking intrinsic motivation into account when it comes to the benefits of nature visits - and the relevance of integrating this consideration into effective green prescriptions".

Matilda van den Bosch, Assistant Professor at The University of British Columbia, said: "For green prescriptions, like with any intervention, it is important to avoid pressure to achieve compliance with the treatment. Nature cannot be forced on anyone, but must be provided at the individual's own pace and will."