Culture

Breeding programs for crops with limited per-plant seed yield require one or more generations of seed increase to generate sufficient quantities for sowing replicated yield trials. The ability to accurately discard low potential lines at these early stages may reduce spending on costly yield testing.

Breeders typically rely on visual selection at these stages because extensive measurement of plant traits is difficult due to the large number of lines under evaluation. However, recent advances in remote sensing have made high-throughput data collection increasingly feasible.

Authors of a recent Crop Science article leveraged unmanned aerial vehicles (UAVs) to record the normalized difference vegetation index (NDVI), a measure of plant health, at the seed increase stage of the International Maize and Wheat Improvement Center's (CIMMYT) wheat breeding program. NDVI measurements were heritable and moderately correlated with grain yield, and results showed that selection based on NDVI would have outperformed visual selection.

Harnessing UAV-collected traits to inform selection at the early stages may improve resource-use efficiency in breeding programs and/or increase rates of genetic gain. As remote sensing technologies become increasingly automated and scalable, breeders will have access to comprehensive suites of traits with which to develop integrative selection strategies.

WEST LAFAYETTE, Ind. - The rapid increase of life-threatening antibiotic-resistant infections has resulted in challenging wound complications with limited choices of effective treatments. About 6 million people in the United States are affected by chronic wounds.

Now, a team of innovators from Purdue University has developed a wearable solution that allows a patient to receive treatment without leaving home. The Purdue team's work is published in the journal Frontiers in Bioengineering and Biotechnology.

A video showing the technology is available at https://youtu.be/UMZpDwYQZJM.

"We created a revolutionary type of treatment to kill the bacteria on the surface of the wound or diabetic ulcer and accelerate the healing process," said Rahim Rahimi, an assistant professor of materials engineering at Purdue. "We created a low-cost wearable patch and accompanying components to deliver ozone therapy."

Ozone therapy is a gas phase antimicrobial treatment option that is being used by a growing number of patients in the U.S. In most cases, the ozone treatments require patients to travel to a clinical setting for treatment by trained technicians.

"Our breathable patch is applied to the wound and then connected to a small, battery powered ozone-generating device," Rahimi said. "The ozone gas is transported to the skin surface at the wound site and provides a targeted approach for wound healing. Our innovation is small and simple to use for patients at home."

Cosmologists have zoomed in on the smallest clumps of dark matter in a virtual universe - which could help us to find the real thing in space.

An international team of researchers, including Durham University, UK, used supercomputers in Europe and China to focus on a typical region of a computer-generated universe.

The zoom they were able to achieve is the equivalent of being able to see a flea on the surface of the Moon.

This allowed them to make detailed pictures and analyses of hundreds of virtual dark matter clumps (or haloes) from the very largest to the tiniest.

Dark matter particles can collide with dark matter anti-particles near the centre of haloes where, according to some theories, they are converted into a burst of energetic gamma-ray radiation.

Their findings, published in the prestigious journal Nature, could mean that these very small haloes could be identified in future observations by the radiation they are thought to give out.

Co-author Professor Carlos Frenk, Ogden Professor of Fundamental Physics at the Institute for Computational Cosmology, at Durham University, UK, said: "By zooming in on these relatively tiny dark matter haloes we can calculate the amount of radiation expected to come from different sized haloes.

"Most of this radiation would be emitted by dark matter haloes too small to contain stars and future gamma-ray observatories might be able to detect these emissions, making these small objects individually or collectively 'visible'.

"This would confirm the hypothesised nature of the dark matter, which may not be entirely dark after all."

Most of the matter in the universe is dark (apart from the gamma radiation they emit in exceptional circumstances) and completely different in nature from the matter that makes up stars, planets and people.

The universe is made of approximately 27 per cent dark matter with the rest largely consisting of the equally mysterious dark energy. Normal matter, such as planets and stars, makes up a relatively small five per cent of the universe.

Galaxies formed and grew when gas cooled and condensed at the centre of enormous clumps of this dark matter - so-called dark matter haloes.

Astronomers can infer the structure of large dark matter haloes from the properties of the galaxies and gas within them.

The biggest haloes contain huge collections of hundreds of bright galaxies, called galaxy clusters, weighing a 1,000 trillion times more than our Sun.

However, scientists have no direct information about smaller dark matter haloes that are too tiny to contain a galaxy. These can only be studied by simulating the evolution of the Universe in a large supercomputer.

The smallest are thought to have the same mass as the Earth according to current popular scientific theories about dark matter that underlie the new research.

The simulations were carried out using the Cosmology Machine supercomputer, part of the DiRAC High-Performance Computing facility in Durham, funded by the Science and Technology Facilities Council (STFC), and computers at the Chinese Academy of Sciences.

By zooming-in on the virtual universe in such microscopic detail, the researchers were able to study the structure of dark matter haloes ranging in mass from that of the Earth to a big galaxy cluster.

Surprisingly, they found that haloes of all sizes have a very similar internal structure and are extremely dense at the centre, becoming increasingly spread out, with smaller clumps orbiting in their outer regions.

The researchers said that without a measure scale it was almost impossible to tell an image of a dark matter halo of a massive galaxy from one of a halo with a mass a fraction of the Sun's.

Co-author Professor Simon White, of the Max Planck Institute of Astrophysics, Germany, said: "We expect that small dark matter haloes would be extremely numerous, containing a substantial fraction of all the dark matter in the universe, but they would remain mostly dark throughout cosmic history because stars and galaxies grow only in haloes more than a million times as massive as the Sun.

"Our research sheds light on these small haloes as we seek to learn more about what dark matter is and the role it plays in the evolution of the universe."

You might need a microscope to witness the next agricultural revolution. New research, published in the journal Science Advances, demonstrates how microfluidic technologies can be used to identify, isolate and propagate specific single photosynthetically active cells for fundamental industry applications and improved ecosystem understanding.

Natural environments are inherently dynamic and require photosynthetic organisms to adapt their physiology to make optimal use of available resources and grow to the best of their abilities. However, not all photosynthetic organisms are equally efficient in this physiological fine-tuning, and where some, for example, succumb to the effects of temperature stress, others persist and grow.

In agriculture, humans have taken advantage of this phenotypic heterogeneity in natural plant populations for thousands of years: the selective breeding of more resistant or productive plant phenotypes has given rise to many of our modern crops and has sustained much of human progress.

While microalgae and cyanobacteria have a similar potential for bioenergy production and biosynthesis of food and chemicals, until now, the tools for their selection have been blunt and unwieldy, relying on bulk culture - akin to selecting for traits in wheat at the level of the landscape.

In this new study, a team of researchers from Sweden, Denmark and Switzerland reports on a novel microfluidic technology called 'PhenoChip' which allows for the identification and selection of unicellular phototrophs under relevant environments.

"Similar to our ancestors selecting a more drought-resistant plant, we can now pick and propagate single phenotypes and start asking fundamental questions. What mechanism causes this phenotype to emerge? Does it persist over many generations? Can we use it to obtain increased biomass yields for biotechnological applications or select resilient phenotypes from natural environments?" says first author Lars Behrendt, Assistant Professor at the Department of Environmental Toxicology at Uppsala University.

In a first-proof-of-concept application, the team used PhenoChip on single cells essential to coral reef health, ecosystems currently under pressure due to changes in climate. In their study, they exposed cells of the coral symbiont Symbiodinium to thermal and chemical treatments, both relevant to the onset of coral bleaching. This enabled the identification of single cells with elevated resilience to rising temperatures and the selection of cells that maintained specific phenotypes for several generations.

PhenoChip's assisted evolution of Symbiodinium could thus help ongoing initiatives aiming to mitigate threats to coral reefs resulting from projected changes in sea surface temperatures and other stressors.

"Conceivably we could use PhenoChip to create a 'library' of desired Symbiodinium phenotypes and try to supply these symbionts--which have not been genetically manipulated but were selected for being more naturally robust--to bleached corals under laboratory conditions. While we don't yet know whether this would improve the ability of corals to recover and persist in the face of future stress, it's an exciting thought," says Behrendt.

What The Study Did: This randomized clinical trial in Brazil of 299 patients with COVID-19 and moderate or severe acute respiratory distress syndrome (ARDS) examined if intravenous dexamethasone plus standard care compared with standard care alone would increase the number of days patients were alive and free from mechanical ventilation.

Authors: Luciano C. P. Azevedo, M.D., Ph.D., of Hospital Sirio-Libanes in São Paulo, Brazil, is the corresponding author.

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

(doi:10.1001/jama.2020.17021)

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

What The Study Did: This randomized clinical trial of patients with severe COVID-19 was stopped early after results from another trial were released but this study investigated whether intravenous hydrocortisone (administered either as a seven-day fixed-dose course or restricted to when shock is clinically evident) improved 21-day organ support-free days.

Authors: Derek C. Angus, M.D., M.P.H., of the University of Pittsburgh, is the corresponding author.

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

(doi:10.1001/jama.2020.17022)

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

What The Study Did: The results of seven randomized clinical trials with 1,703 critically ill patients with COVID-19 were combined to estimate the association between administration of corticosteroids compared with usual care or placebo and the risk of death after 28 days.

Authors: Jonathan A.C. Sterne, M.A., M.Sc., Ph.D., of the University of Bristol in England, is the corresponding author.

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

(doi:10.1001/jama.2020.17023)

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

Researchers from McGill University have revealed the steps by which two very distinct organisms - bacteria and carpenter ants - have come to depend on one another for survival to become a single complex life form. The study, published today in Nature, shows that the two species have collaborated to radically alter the development of the ant embryo to allow this integration to happen. Understanding how such grand unifications originate and evolve is a major puzzle for biologists. Ehab Abouheif, a biologist and senior author on the paper believes that these insights may lead to a better understanding of the origin of complex organisms.

The bacteria Blochmannia and members of the hyper-diverse ant tribe Camponotini have forged a symbiotic relationship that goes back 51 million years in which each species can no longer survive without the other (termed obligate endosymbiosis by biologists). The ants are thought to have initially ingested the bacteria from sap-sucking insects called hemipteran bugs, with whom they share an ecological niche. The bacteria, which live inside the cells of the ant, helps regulate the size distribution of workers in the colony by enhancing the ants' ability to synthesize nutrition. The ants, in turn, provide the bacteria with a protected cellular environment and ensure their survival from one generation to the next. But how they came together has been unclear until now.

A radically reorganized embryo development

The researchers began to look closely at genes that regulate the germline, the material that contains the genetic information (such as ova and sperm in humans) that is passed from one generation to the next, after observing that the bacteria completely surrounds the germline.

"Instead of the germline genes being localized in just one location in the egg like all other insects, now they are in four. No one has ever seen anything like this in any other insect," says Arjuna Rajakumar, a senior PhD student in Prof. Abouheif's lab and a first co-author of the paper with Ab. Matteen Rafiqi, a former postdoc in the Abouheif lab who is now based at Bezmialem Vakif University in Istanbul. "We were also surprised that the hox genes, which set up the layout of the body and normally come on late in embryo development appeared very early and localize in the same four locations as the germline genes." says Rafiqi.

"The localization of these genes in these 4 different areas creates a system of coordinates in the ant embryo, where each performs a different function to integrate the bacteria." says Abouheif.

Uncovering the steps towards a major evolutionary transition

Working with over 30 closely-related species of ants allowed the researchers to reconstruct the steps in this unification. They discovered that the merger happened in a series of steps, going from embryos where germline genes were localized in only one location, until eventually both germline and hox genes could be found in all four. However, a major surprise was that embryos with two locations of these genes evolved prior to the merger between the two species. This means that there was a pre-existing capacity to evolve new locations within the ant embryos, which the bacteria were then able to exploit to make radical alterations to embryo development and integrate the two species.

"We propose the bold idea that the steps we uncovered for the way these bacteria and ants got together to form an obligate endosymbiotic relationship will help us understand other major unifications that gave rise to complex life forms, like when unicellular organisms got together to form multicellular organisms" said Abouheif.

BOSTON - Kidneys from deceased donors with hepatitis C virus (HCV) infection can be safely transplanted into noninfected recipients when a regimen of direct-acting antiviral therapies is initiated as early as two days after the transplant, according to a study from Massachusetts General Hospital (MGH). In a multi-center clinical trial reported in the Journal of the American Society of Nephrology, MGH researchers found that each of 30 kidney recipients were cured of HCV with no serious side effects attributable to the antiviral therapy, and that nearly all maintained excellent allograft function at six months.

"We successfully treated the hepatitis C virus in kidneys transplanted from HCV-positive donors by using the antiviral agents glecaprevir and pibrentasvir as part of an eight-week course of daily dosing," says Meghan Sise, MD, investigator in the Division of Nephrology at MGH and co-first author of the study. "These findings could carry a strong message to the many transplant centers that are still wary about or resistant to using kidneys from HCV-infected donors. We've shown that these so-called donor positive to recipient negative transplants can be done safely and effectively through early antiviral intervention."

Nearly 95,000 people in the U.S. are currently waiting for kidney transplant, most suffering progressive health deterioration. For some groups, including patients over 60, death is a greater certainty than a transplant. Given this significant public health problem, the U.S. Department of Health and Human Services set a goal of doubling the number of kidneys available for transplantation by 2030 as part of the Advancing American Kidney Health Initiative. One promising pathway toward that target is reducing the discard of viable human kidneys that now occurs, particularly from deceased individuals with hepatitis C virus infection. The number of those organs has soared over the past five years as a result of mounting deaths from the national opioid epidemic.

The MGH prospective trial is the first multi-center investigation to show the feasibility of donor positive to donor negative transplantation. Known as MYTHIC (Multi-Center Study to Transplant Hepatitis-C Infected Kidneys), the study was conceived and carried out in collaboration with the Perelman School of Medicine at the University of Pennsylvania. Each of the trial's 30 kidney recipients at seven U.S. transplant centers was given an eight-week course of a coformulation of glecaprevir and pibrentasvir, powerful antiviral agents that target two distinct proteins within the virus that are essential to its survival.

While one patient died of complications of sepsis deemed unrelated to trial participation, no severe side effects or liver disease were observed in any patient, and allograft function at six months was excellent. "Many of the patients showed a tiny amount of virus in their blood right after transplant, but that viral load became undetectable or unquantifiable in all recipients of HCV-viremic kidneys by four weeks of treatment, " notes Raymond Chung, MD, investigator in the Liver Center and Gastrointestinal Division at MGH and co-senior author of the study.

The trial's success extends to the development by the research team of an evidence-based clinical protocol for transplanting hepatitis C-infected kidneys that could be used by transplant centers anywhere. "We sought to replace the many homegrown protocols based on varying treatment regimens with one that is sound, uniform and reproducible," explains Chung. "We believe we have succeeded by creating a very simple approach that works in patients."

Researchers are now hopeful that transplant centers will take notice of these encouraging results and the opportunity they afford to increase access to high quality organs by patients in critical need of a kidney transplant. "By showing that these procedures are effective," says Sise, "we're hoping that insurance companies will also see the enormous benefit of making transplants with hepatitis-C infected kidneys uniformly covered and reimbursable. The ultimate goal of everyone should be to increase the quality and quantity of life for patients waiting for a kidney transplant."

AMES, Iowa - A recently published analysis of data on tagged monarch butterflies migrating from the United States to Mexico emphasizes the importance of creating new habitat to ensure the future of the species' iconic migratory pattern.

The study, published this month in the peer-reviewed journal Frontiers in Ecology and Evolution, drew on data collected on 1.4 million monarch butterflies that were tagged in the United States Midwest from 1998 to 2015. The study presents evidence that the migration success of monarchs hasn't declined and thus cannot explain the steep decline in the monarch population over the last few decades.

Several lines of evidence support the primary hypothesis for the monarch population decline, which is the loss of milkweed habitat. John Pleasants, an adjunct associate professor in Iowa State University's Department of Ecology, Evolution and Organismal Biology, said the analysis should put to rest this persistent alternative explanation for the population decline that posits monarch butterflies are experiencing increasing mortality during their fall migration to Mexico, Pleasants said.

"If there was some problem with migration, we should have found fewer tagged monarchs recovered in Mexico over time, but that was not the case," he said.

Monarch butterflies carry out a remarkable migration pattern year after year. Monarchs born in Midwestern states move south during the late summer and fall and arrive in central Mexico for the winter. The monarchs then move northward again in the spring. But the monarch population has dwindled to such an extent over the last two decades that scientists worried the migratory system could collapse forever.

Focus on milkweed

In response, the Iowa Monarch Conservation Consortium, a diverse partnership of 45 organizations supported by Iowa State University, the Iowa Department of Agriculture and Land Stewardship, and the Iowa Department of Natural Resources, is spearheading an effort to plant between 480,000 and 830,000 acres of new habitat by 2038. This effort focuses on milkweed, the only plant on which monarchs will lay eggs.

Pleasants said some researchers looked at yearly surveys of monarch adults and did not find a decline at the same time the overwintering population in Mexico was falling and hypothesized that increasing mortality during the southward migration may be driving the overall population decline. Those researchers suggested increased parasite load or declining nectar availability in Texas might contribute to migratory mortality. However, Pleasants said no reliable data show a decline in those factors. Instead, Pleasants said the data show no trend in the tag recovery rate, an indication the migratory journey hasn't become more dangerous over the years.

Pleasants said the discrepancy between the surveys of the summer populations and the overwintering population likely stems from the loss of milkweed habitat on agricultural land in the Midwest. Milkweed was once plentiful in farm fields, providing plenty of habitat for monarchs in rural areas, until about 2006 when it had all but disappeared due to herbicide use. Surveys done in the late 1990s and early 2000s did not include field habitat and therefore missed the monarchs in fields, underestimating the true size of the population, Pleasants said. Since 2006, population estimates from those surveys have been highly correlated with overwintering numbers.

"Our analysis points us back to the idea that the loss of milkweeds, particularly from agricultural fields, is most responsible for this decline," he said. "If you want to bring the monarch butterfly back, you need to bring the milkweeds back."

Our gut microbiota can crucially influence our behaviour and neurodevelopment. New research of the Ethology Department at the Faculty of Science at Eötvös Loránd University indicates that dogs' aging mechanism and memory performance are also linked to their gut microbiome composition. According to the study, dogs and humans may have similar mechanisms in cognitive aging.

Dogs have become a valuable model for complex human traits and disorders

In humans, intestinal microbiome composition has been linked to psychiatric conditions such as depression, anxiety, and autism, as well as neurodegenerative disorders, including Parkinson's and Alzheimer's disease through metabolites produced by gut-inhabiting bacteria. The wide range of expected lifespans, a natural inclination to develop dementia, and an environment shared with humans have made companion dogs a promising model organism in aging research. The gut microbiome of dogs is more similar to that of humans than that of mice and pigs. "Next-generation DNA sequencing techniques have enabled the identification of the taxonomic composition and also the potential functions of the microorganisms, gaining a better understanding of microbial-host interactions" - says Tamás Felföldi, assistant professor at the Department of Microbiology, ELTE, Budapest, who usually studies the microbial communities of natural waters, such as the Lake Balaton.

Collecting and analyzing the samples

Eniko Kubinyi, the principal investigator of the Senior Family Dog Project at ELTE, funded by the European Research Council, teamed up with microbiologists to investigate the gut microbiome of a group of companion dogs and examined possible links with age and cognitive performance. "After we tested the memory performance of the dogs at the Department of Ethology, ELTE, we took them for a walk, and collected fecal samples. We had to immediately freeze the excrement in storage containers to ensure they would provide a valid picture about the bacteria that lived in the dogs guts before defecation." According to Sara Sandor, geneticist, "the time limit is important, as some species of bacteria can continue proliferation after defecation, and therefore may falsely outnumber other bacteria in the sample".

Overall, the involvement of family dogs represented a relatively novel approach in this field as it included a huge variety of animals, regarding breed, diet, and life history. This leads to a large statistical variance in their bacterial communities' composition, yet, this approach is crucial if researchers aim to model the natural variability of human populations. "A main limitation of the current study is the relatively low number of subjects, 29 dogs. However, the results of such exploratory studies can facilitate new research efforts, especially if they indicate medically relevant trends in the data" - points out Soufiane Bel Rhali, PhD student.

A link between cognitive performance, age and gut microbiome composition

The researchers found a negative correlation between the abundance of Fusobacteria phylum and the chronological age in dogs. Interestingly, in humans, Fusobacteria were shown to increase with aging and elevated abundance of these microbes have been linked to serious illnesses, like inflammatory bowel disease and colorectal cancer. Therefore, the current finding seems to support an already formed hypothesis that Fusobacteria play a fundamentally different, beneficial role in carnivores as compared with humans. "The identification of such differences between dogs and humans are at least as important as exploring the shared patterns in gut microbial composition, since ungrounded assumptions of similarity can lower the translational value of intervention studies." - notes Kubinyi.

Moreover, the current study found that dogs performing worse in a short-term memory test had relatively more Actinobacteria. This finding can indicate a shared mechanism underlying dogs' and humans' cognitive aging, since Actinobacteria were also shown to be more abundant in the intestines of Alzheimer patients.

A link between cognitive performance, age and gut microbiome composition in companion dogs was hypothesized but not described before. The new research, although preliminary regarding the association between cognition and gut microbiome composition, opens up new venues in canine aging and neurodevelopmental research.

The humble ink in a tattoo artist's needle could be the key to improving the detection of cancer, thanks to new research from the USC Viterbi Department of Biomedical Engineering.

WiSE Gabilan assistant professor in the department with a lab at the USC Michelson Center for Convergent Bioscience, Cristina Zavaleta and her team recently developed new imaging contrast agents using common dyes such as tattoo ink and food dyes. When these dyes are attached to nanoparticles, they can illuminate cancers, allowing medical professionals to better differentiate between cancer cells and normal adjacent cells. The work has been published in Biomaterials Science.

Early detection is crucial for patients to have the best possible outcomes from cancer; a disease that will affect over 38% of Americans at some point in their lifetime.

However, detection is challenging without good imaging agents; contrast materials which when injected into patients, allow for imaging such as MRI and CT to function with better sensitivity and specificity, enabling medical professionals to diagnose with accuracy, and for surgeons to identify the exact margins of tumors.

"For instance, if the problem is colon cancer, this is detected via endoscopy," Zavaleta said. "But an endoscope is literally just a flashlight on the end of a stick, so it will only give information about the structure of the colon ­- you can see a polyp and know you need to take a biopsy."

"But if we could provide imaging tools to help doctors see whether that particular polyp is cancerous or just benign, maybe they don't even need to take it," she said.

Illuminated nanoparticles move through a blood vessel to find cancer. The coloring dyes were incorporated into nanoparticles to allow for more sensitive imaging contrast when identifying cancerous cells.

To achieve this, the team has discovered a unique source of optical contrasting agents from the household coloring dyes and pigments that we routinely encounter. These "optical inks" can be attached to cancer-targeting nanoparticles to improve cancer detection and localization.

The dyes and pigments were discovered from common coloring agents that already have U.S. Food and Drug Administration (FDA) approval, which the team hopes may enable them to be more easily and safely implemented in imaging practice.

For Zavaleta, inspiration struck in an unusual place -- an animation class with Pixar artists in Emeryville, California, the home of the famed studio. Zavaleta, who enjoys art and animation among her hobbies, said she was intrigued by the inks and paints that the artists brought to class.

"I was thinking about how these really high pigment paints, like gouache watercolors, were bright in a way I hadn't seen before, and I was wondering if they had interesting optical properties," Zavaleta said.

The idea led her to tattoo artist in nearby San Francisco, Adam Sky, another artisan working with bright dyes.

"I remember I brought a 96-well plate and he squirted tattoo ink into each of the wells," Zavaleta said. "Then I took the inks to our Raman scanner (used to sensitively detect our tumor-targeting nanoparticles) and discovered these really amazing spectral fingerprints that we could use to barcode our nanoparticles. It was super cool."

One of the safety challenges of imaging using nanoparticles, is that often these nanoparticles can have a prolonged retention in organs like the liver and the spleen, which are responsible for trying to break down the nanoparticle. Because of these safety concerns, it's crucial to consider biodegradable nanomaterials. Currently, there are a limited amount of optical contrast agents approved for clinical use.

With this in mind, Zavaleta's team considered common food dyes that could be used to decorate the nanoparticles, such as the dyes found in colorful candies like Skittles and M&Ms. These brightly colored food products that humans routinely consume have been deemed by the FDA as safe for human consumption.

"We thought, let's look at some of the FDA-approved drug, cosmetic and food dyes that exist and see what optical properties are amongst those dyes," Zavaleta said. "And so that's where we ended up finding that many of these FDA-approved dyes have interesting optical properties that we could exploit for imaging."

The team has developed a nanoparticle that will carry these highly pigmented imaging agents as a "payload." Zavaleta said the particles are of a specific size that enables them to passively penetrate into tumor areas, but can also be retained due to their size.

Most of the imaging contrast agents used in the clinic today are small molecule dyes.

"With small molecules, you may be able to see them accumulate in tumor areas initially, but you'd have to be quick before they end up leaving the tumor area to be excreted," Zavaleta said. "Our nanoparticles happen to be small enough to seep through, but at the same time big enough to be retained in the tumor, and that's what we call the enhanced permeability and retention effect."

The nanoparticle can also be "decorated" with a larger payload of the dye than previous small molecule imaging agents, which the team has shown under fluorescence imaging leads to brighter signal and significant localization of the nanoparticles in tumors.

"If you encapsulate a bunch of dyes in a nanoparticle, you're going to be able to see it better because it is going to be brighter," Zavaleta said. "It's like using a packet of dyes rather than just one single dye."

Tropical Depression 15 strengthened into a tropical storm late on Sept. 1 and was renamed Omar. Visible imagery from NASA-NOAA's Suomi NPP satellite was compiled into an animation that showed the system's formation and strengthening. NASA's Terra satellite also provided temperature data on Omar that revealed wind shear was affecting the storm.

Another Record-Breaker

Omar is the 15th named storm of the 2020 Atlantic hurricane season, and is the earliest 15th storm on record, besting the previous mark by about a week from Ophelia of 2005.

NASA Animates Omar's Development

At NASA's Goddard Space Flight Center in Greenbelt, Md. using the NASA Worldview platform an animation of satellite imagery was created to show Omar over three days. Using visible imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard NASA-NOAA's Suomi NPP satellite, an animation shows the development, organization and movement of Tropical Depression 15 from Aug. 30 to Sept. 1 off the coast of North Carolina. On Sept. 2, it became Tropical Storm Omar.

This animation of visible imagery from the VIIRS instrument aboard NASA-NOAA's Suomi NPP satellite shows the organization and movement of Tropical Depression 15 from Aug. 30 to Sept. 1 off the coast of North Carolina. On Sept. 2, it became Tropical Storm Omar. Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Infrared Data Reveals Wind Shear Battering Omar

Strong upper-level winds are battering Omar and pushing the strongest storms to the southeastern quadrant. Those northwesterly winds are not expected to let up, putting Omar on a weakening trend. NASA's infrared data showed how those outside winds were displacing the strongest storms in Omar's circulation.

On Sept. 1 at 10 p.m. EDT (Sept. 2 at 0200 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite gathered temperature information about Tropical Storm Omar's cloud tops. MODIS found the most powerful thunderstorms were on the southeastern side of the storm, where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

"Satellite images show that the system remains sheared with a bursting pattern on satellite, occasionally exposing the center, and a large area of curved bands in the southeastern quadrant of the circulation," Eric Blake wrote in the 5 a.m. EDT Omar Discussion. Blake is a senior hurricane specialist at NOAA's National Hurricane Center (NHC) in Miami, Florida.

Omar's Status on Sept. 2

At 5 a.m. EDT (0900 UTC), NOAA's NHC noted the center of Tropical Storm Omar was located near latitude 36.2 degrees north and longitude 68.7 degrees west. Omar was centered about 350 miles (560 km) northwest of Bermuda. The storm is moving toward the east-northeast near 14 mph (22 kph), and this general motion is expected to continue through this afternoon. Maximum sustained winds are near 40 mph (65 km/h) with higher gusts. Little change in strength is expected through tonight. The estimated minimum central pressure is 1003 millibars.

Omar's Bleak Forecast

The NHC forecast calls for Omar to turn toward the east during the evening hours on Sept. 2, with a reduction in forward speed occurring through Friday, Sept. 4. Weakening should begin by Thursday, Sept. 3, with Omar likely to become a remnant low-pressure area by Thursday night.

Alzheimer's disease is a neurodegenerative condition that is characterized by the buildup of clumps of beta-amyloid protein in the brain. Exactly what causes these clumps, known as plaques, and what role they play in disease progression is an active area of research important for developing prevention and treatment strategies.

Recent studies have found that beta-amyloid has antiviral and antimicrobial properties, suggesting a possible link between the immune response against infections and the development of Alzheimer's disease.

Chemical biologists at the Sloan Kettering Institute have now discovered clear evidence of this link: A protein called IFITM3 that is involved in the immune response to pathogens also plays a key role in the accumulation of beta-amyloid in plaques.

"We've known that the immune system plays a role in Alzheimer's disease -- for example, it helps to clean up beta-amyloid plaques in the brain," says Yue-Ming Li, a chemical biologist at SKI. "But this is the first direct evidence that immune response contributes to the production of beta-amyloid plaques -- the defining feature of Alzheimer's disease."

In a paper published September 2 in Nature, Dr. Li and his team show that IFITM3 alters the activity of an enzyme called gamma-secretase, which chops up precursor proteins into the fragments of beta-amyloid that make up plaques.

They found that removing IFITM3 decreased the activity of the gamma-secretase enzyme and, as a result, reduced that number of amyloid plaques that formed in a mouse model of the disease.

Mounting Evidence for a New Hypothesis

Neuroinflammation, or inflammation in the brain, has emerged as an important line of inquiry in Alzheimer's disease research. Markers of inflammation, such as certain immune molecules called cytokines, are boosted in Alzheimer's disease mouse models and in the brains of people with Alzheimer's disease. Dr. Li's study is the first to provide a direct link between this inflammation and plaque development -- by way of IFITM3.

Scientists know that the production of IFITM3 starts in response to activation of the immune system by invading viruses and bacteria. These observations, combined with the new findings from Dr. Li's lab that IFITM3 directly contributes to plaque formation, suggest that viral and bacterial infections could increase the risk of Alzheimer's disease development. Indeed, Dr. Li and his colleagues found that the level of IFITM3 in human brain samples correlated with levels of certain viral infections as well as with gamma-secretase activity and beta-amyloid production.

Age is the number one risk factor for Alzheimer's, and the levels of both inflammatory markers and IFITM3 increased with advancing age in mice, the researchers found.

They also discovered that IFITM3 is increased in a subset of late onset Alzheimer's patients, meaning that IFITM3 could potentially be used as a biomarker to identify a subset of patients who might benefit from therapies targeted against IFITM3.

The researchers next plan is to investigate how IFITM3 interacts with gamma-secretase at the molecular and atomic levels and how it is involved in neuroinflammation in animal models. They will also explore IFITM3 as a biomarker for the disease and as a potential target for new drugs designed to treat it.

House sparrows can be found on nearly every continent including North America, South America, Africa and Australia, where they are not native but an invasive species. New research into these highly social songbirds reveals that they can learn from each other and adapt their behavior.

"Our study demonstrates that house sparrows can extrapolate information gleaned from the social environment and apply it to new experiences," said Tosha Kelly, LSU Department of Biological Sciences post-doctoral researcher and lead author in this study published in Biology Letters.

House sparrows can often be observed in large flocks and this research suggests they may watch and learn from each other. The ability of house sparrows to adjust their behavior after a social experience provides evidence of social learning.

"This is really important because as humans encroach upon and develop wildlife habitats, animals are exposed to a variety of environments and objects that they wouldn't naturally be exposed to. It's critical to understand how quickly new information can pass through a population, which can affect how a species, as a whole, is going to persevere in this era of human-induced environmental change," Kelly said.

Kelly and colleagues video recorded, in a lab environment, how individual house sparrows reacted to a new object placed near the food bowl in their cage. Some sparrows did not hesitate to feed at their bowl despite the new object, while others were more reluctant to approach the bowl with the unusual object nearby. The new objects were harmless to the birds and were introduced one at a time. The objects included a blinking light, a white cover over part of the dish, yellow pipe cleaners, a purple plastic egg, a red-painted dish, a tinfoil hood, three gold bells, pink puffs and an open blue cocktail umbrella. Each bird was exposed to three of these objects one at a time to determine its "personality type."

The researchers paired 10 individual birds with similar responses to the new objects and 14 birds with contrasting responses to the objects. Then, the pairs were exposed to unusual objects near the food dish that were new to both individuals in each pair's shared cage. Kelly and colleagues observed through video recordings that the more wary individual had the opportunity to observe the more daring individual feed at the bowl near the new object. Then, all of the birds were returned to their individual cages and a week later, they were tested alone again with new objects near the food dish. Surprisingly, the birds that had previously been more cautious but had watched a daring partner began to be more daring when feeding alone at their food bowl, even with a completely new object they had never seen before nearby.

A week after being housed with a more daring partner, cautious house sparrows were on average 2.6 times more likely to feed in the presence of a new object than compared to when initially tested alone. This demonstrates that they learned from their partners that novel objects near the food dish were not a threat, write the authors.

"A lot of species that get introduced don't become established, but house sparrows are very successful. Our findings from this study might be part of what explains their success as an invasive species," said LSU Department of Biological Sciences Assistant Professor Christine Lattin, who is the senior author on this study. "How an individual species responds to novelty can have a big impact on whether or not they can coexist with people in cities and other human-altered environments. It may also indicate whether they are going to be able to benefit from increased food availability and other kinds of opportunities that humans bring along with them or if they are going to just be shut out."