Culture

Domestic cats, like many other mammals, use smelly secretions from anal sacs to mark territory and communicate with other animals. A new study from the Genome Center at the University of California, Davis shows that many odiferous compounds from a male cat are actually made not by the cat, but by a community of bacteria living in the anal sacs. The work is published Sept. 13 in PLOS ONE.

"Cats use a lot of volatile chemicals for signaling, and they probably don't make them all," said David Coil, project scientist at the Genome Center and an author on the paper.

Many species - including cats, dogs, bears, pandas, skunks and hyenas - use anal sac secretions as a chemical language. Skunks, of course, also use them as a means of defense.

The experiment grew out of the KittyBiome Project started at the Genome Center by Holly Ganz, a postdoctoral researcher working with Coil and Jonathan Eisen, professor of evolution and ecology in the UC Davis College of Biological Sciences. The KittyBiome Project has since been spun off as AnimalBiome, a company with Ganz as CEO.

The researchers obtained anal sac secretions from a single male Bengal cat volunteered to participate by its owner. They extracted DNA for sequencing to identify types of bacteria, and also took samples for chemical odor analysis in Professor Cristina Davis' laboratory in the UC Davis Department of Mechanical and Aerospace Engineering.

Sequencing showed that the microbial community was not very diverse and dominated by a small number of bacterial genera.

"There are not a lot of players there," Coil said.

Analyzing volatile organics

The most abundant bacteria from the screen were grown in culture. Mei Yamaguchi, a postdoctoral researcher in Davis' lab, analyzed the volatile chemicals given off by the bacteria.

Davis' lab focuses on technology for detecting and characterizing low levels of volatile organic compounds that can be markers of health and disease, from influenza in humans to citrus greening in fruit trees.

Yamaguchi and Davis were able to detect 67 volatile compounds released by the bacterial cultures. Fifty-two of these compounds were also found directly in the anal sac secretions.

The results support the idea that the bacterial community, not the cat itself, produces many of the scents used by the cat to communicate.

Coil and colleagues want to follow up by looking at more cats. If these scents are made by bacteria, why do cats smell different to each other? How do cats acquire the bacteria and do they change over life? Understanding how microbes influence their scent could have wide implications for understanding scent communication in animals.

Toxoplasma gondii, the unicellular causative agent of toxoplasmosis, reproduces itself in an unusual fashion by means of an internal budding process. This entails the development of two daughter cells within the cytoplasm of the mother cell. On completion of this process, the mother cell undergoes lysis, and the daughter cells are released into the infected host cell. The daughter cells continue to proliferate until the host-cell itself finally bursts. T. gondii is a globally distributed infectious agent. As a rule, the infection is innocuous. However, during pregnancy, transmission of the parasite to the fetus can severely damage the development of the latter. A group of researchers led by Markus Meissner, Professor of Experimental Parasitology at LMU in collaboration with Dr. Javier Periz at Glasgow University, has now described a phenomenon which plays an important role in asexual reproduction - during internal budding, components of a specific organelle are donated by the mother cell to the daughters. The study appears in the online journal Nature Communications.

In order to recognize, adhere to and infect host cells, T. gondii makes use of organelles called rhoptries and micronemes, which secrete a set of specialized proteins that enable the parasite to invade the target cell. Once the infection has been successfully established, the parasite divides. It had been assumed up to now that the micronemes in the daughter cells are reformed from scratch. However, by specifically labelling one of the micronemal proteins, the authors of the new study were able to follow the fate of the microneme during the cell cycle with the aid of high-resolution microscopy. The observations revealed that the components of the mother cell's microneme are divided more or less equally between the daughter cells. In addition, micronemal proteins are newly synthesized in the daughter cell. The researchers assume that this recycling is not limited to the micronemes, but serves as a more general mechanism to enable the reassembly of organelles that are vital for propagation of the parasite.

"Furthermore, we have shown that recycled micronemes are transported from mother to daughter by the actin filaments of the cytoskeleton," says Markus Meissner. "This is an entirely new function for actin in the parasite. Up to now, actin was thought to be involved solely in cell motility in T. gondii. When we have a better understanding of how this newly discovered function of actin is regulated, we may also be able to identify novel drug targets. This is a very interesting prospect because T. gondii is known to possess very few actin-regulating proteins."

A new study on menopausal women shows that leisure-time physical activity is associated with a healthier blood lipid profile. However, results suggest that leisure-time physical activity does not seem to entirely offset the unfavorable lipid profile changes associated with the menopausal transition.

Women experience a rapid increase in cardiovascular disease (CVD) risk after the onset of menopause. This observation suggests the presence of factors in middle-aged women that accelerate the progression of CVD independent of chronological aging.

"It is well known that physical activity has health benefits, yet it is less clear to what extent physical activity can prevent the negative changes seen in blood lipid profiles during the menopausal transition," says Matthew Jergenson, MD, from the University of Minnesota Medical School, Minneapolis, Minnesota. "The present study examined menopausal women in the city of Jyväskylä, Finland, to explore the role of leisure-time physical activity on CVD risk factors."

ERMA study examines the effects of menopause

The present study is part of the Estrogenic Regulation of Muscle Apoptosis (ERMA) study, which examines the role of menopause on body composition, leisure-time physical activity and the risk of metabolic diseases.

"Based on our findings, leisure-time physical activity was associated with a healthier blood lipid profile," explains postdoctoral researcher Sira Karvinen from the Gerontology Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland. "Yet advancing menopausal status predicted a less healthy lipid profile, suggesting that leisure-time physical activity does not entirely offset the unfavorable lipid profile changes associated with the menopausal transition."

More specifically, higher leisure-time physical activity was associated with lower total cholesterol, LDL, triglyceride and fasting blood glucose levels as well as higher HDL levels. Advancing menopausal status, in turn, was associated with higher total cholesterol, triglyceride and LDL levels.

"However, leisure-time physical activity may attenuate the unfavorable atherogenic changes in the serum CV risk factors of healthy middle-aged women," Jergenson and Karvinen state. "Hence one should not forget sport-related hobbies at middle age."

The present study is part of the Estrogenic Regulation of Muscle Apoptosis (ERMA) study, a population-based cohort study (n = 886) of middle-aged Caucasian women between 47 and 55 years of age in the Jyväskylä area. In addition, 193 women composed a longitudinal study population that was followed over the menopausal transition. Physical activity was assessed both by self-reported questionnaires and accelerometer monitoring. Serum lipid profiles (total cholesterol, LDL, HDL, triglycerides, fasting blood glucose) were analyzed to quantify cardiovascular risk factors.

For decades pollution in China has paralleled economic growth. But this connection has been weakened in recent years, according to a new international research study published in the Science Advances journal.

The study was conducted by an international team of researchers from five countries, including Deliang Chen, a professor of physical meteorology at the University of Gothenburg and a Coordinating Lead Author of the UN Intergovernmental Panel on Climate Change (IPCC).

"Our research shows that increased environmental awareness and investments in China over the past decade have produced results," says Chen.

Economic growth has come at a high price

In the late 1970s China's economy began expanding, and the expansion accelerated during the following decades. Environmental pollution kept pace with economic growth.

"But the analysis of our data shows a weakening of that relationship for China starting in 1995," Chen says.

Researchers have studied statistics for economic growth, environmental conditions, regional differences, the gap between urban and rural areas, social inequality, land-based impacts on the ocean, equality in education, health care and living standards in China during the 1977-2017 period. The research results are based on huge amounts of "big data".

"In our study we have looked at the data from all areas based on the UN's 17 Sustainable Development Goals (SDGs). As researchers, we normally tend to look at our own data, but in this study, we have used existing data from many different sources."

Major challenges remain, despite progress

The study shows that environmental pollution in China as a whole has begun to decline, but that greenhouse gas emissions have continued to increase.

The study also shows that China has improved in 12 of the 17 SDGs during the last 40 years, while major problems still exist in the other five.

"China's economic growth has not come without great sacrifice and with negative consequences for the environment and climate. But it is still encouraging to note these improvements. At the same time, it reminds us of the urgent need to solve major problems such as increased greenhouse gas emissions and inequality of income.

Many believe that economic progress and pollution have to go hand in hand. But our study shows that this connection has become weaker in recent years in China. And it provides a little more hopeful picture. This hope and the lessons learned in China can be interesting for other countries that also need to be developed."

Big data is digitally stored information so massive (usually terabytes and petabytes) that it is difficult to process with traditional database methods.

60% of respondents reported difficulty affording treatment -

Nearly half of respondents reported undergoing step therapy -

Two-thirds of respondents reported activity and lifestyle limitations due to their disease

ATLANTA - Americans living with rheumatic disease face significant healthcare challenges, according to a national patient survey released this week by the American College of Rheumatology and its Simple Tasks™ public awareness campaign.

More than 1,500 U.S. adults living with rheumatic disease responded to the survey, which asked a range of questions related to healthcare access, affordability and lifestyle. The results come as patients, providers and policymakers throughout the U.S. recognize Rheumatic Disease Awareness Month (RDAM).

Key survey findings include:

Even though 90 percent of respondents reported having health insurance coverage, nearly 60 percent said they had difficulty affording their medications or treatments in the past year.

Almost half of patients receiving treatment for a rheumatic disease reported that their insurance company subjected them to step therapy, a process that requires them to try - and fail - treatments preferred by the insurance company before a doctor-prescribed option can be approved, even when a patient's doctor is uncertain the insurer-preferred option will be effective.

One-quarter of respondents reported out-of-pocket costs greater than $1,000 per year for treatment, while six percent of patients reported out-of-pockets costs greater than $5,000 per year.

Close to 60 percent of respondents are currently being treated by a rheumatologist or have been referred to seek treatment by a rheumatologist. However, two-thirds had to wait more than 30 days after referral before getting an initial appointment with a rheumatologist.

Almost two-thirds of patients reported that their rheumatic disease limited their ability to perform simple tasks such as eating, getting dressed, cooking, or running errands.

"These findings make clear that Americans living with rheumatic disease - regardless of age, gender, or income level - struggle to find affordable care," said Paula Marchetta, MD, MBA, president of the ACR. "To address these challenges, it is crucial for patients, clinicians, and policymakers to work together to improve access to rheumatology care so that patients can live longer, healthier, and more fulfilling lives."

Rheumatology patients recently joined the ACR on Capitol Hill to urge lawmakers to support legislation that would improve patient access by expanding the rheumatology workforce and placing reasonable limits on the use of step therapy.

Last year, the ACR examined access, affordability, and lifestyle challenges in the 2018 Rheumatic Disease Report Card, which graded each of the 50 states and the District of Columbia on the factors associated with an individual's ability to live well with a rheumatic disease. The 2019 survey provides additional context to these challenges by asking patients directly how their disease impacts daily life.

According to the Centers for Disease Control and Prevention (CDC), an estimated one in four Americans - 54 million U.S. adults - have been diagnosed with a rheumatic disease, an umbrella term that includes conditions such as rheumatoid arthritis, lupus, gout, osteoarthritis, Sjögren's syndrome, juvenile idiopathic arthritis, and hundreds of lesser known diseases.

Hundreds of thousands of children also live with arthritis and other rheumatic diseases. The CDC estimates that as many as 300,000 children in the U.S. have some type of juvenile arthritis. Rheumatic diseases are the nation's leading cause of disability and generate $140 billion in annual health costs. Although there is no cure for rheumatic disease, early intervention and diagnosis by a rheumatologist can help patients manage symptoms and lifestyle limitations to live healthier and more active lives.

A group of scientists from Skoltech, the Moscow Institute of Physics and Technology, and the State University of Aerospace Instrumentation in St. Petersburg has won the Best Paper Award at the prestigious fifth IEEE International Conference on Internet of People (IoP 2019) for research on artificial intelligence, which established a connection between an esports player's movements and skill level. The research findings show that machine learning methods can accurately predict a player's skill level in 77% of cases.

In just a few years, esports have evolved from video games for schoolkids to a full-fledged industry with professional teams, coaches, and huge investments. Like in any other sport, an esports player can be a professional or an amateur, and telling one from the other is essential for optimizing the training process.

Master's students from the three Russian universities, led by Skoltech professors Andrey Somov and Evgeny Burnaev, looked for a connection between the gaming proficiency and body movements of an esports player seated in a chair.

"We hypothesized that there could be a link between a player's body movements and skill level. Also, it was interesting to look at the players' responses to various game events, such as kills, deaths, or shootings. We suspected that professional players and beginners would react differently to the same event," explains the study's first author Anton Smerdov, a graduate student at Skoltech and MIPT.

The experiment involved a total of 19 players, including nine professionals and 10 amateurs, who were asked to play Counter-Strike: Global Offensive (CS:GO) for 30 to 60 minutes. Their skill level was approximated as hours spent playing, similarly to how flight hours reflect pilot experience. The data were collected using an accelerometer and a gyroscope embedded in a chair.

"We then cut the data into three-minute sessions, assuming three minutes to be enough for understanding a player's behavior and obtaining a sample large enough for algorithm learning," Smerdov added.

The patterns extracted from each session were used to evaluate the players' behavior and check how intensively and how often they moved or turned around along each of the three axes, or leaned back in the chair. A total of 31 patterns were obtained for each player, and eight most important features were defined using statistical techniques. Machine learning methods were then applied to the key features. The popular random forest method displayed the best performance, correctly determining a player's skill level from a three-minute session 77% of the time. Also, the results showed that professional players move around more often and more intensively than beginners, while sitting perfectly still during shootouts and other game events.

The team led by professors Somov and Burnaev has been studying esports players' psycho-emotional state and physical responses to the game using sensors and machine learning methods since 2018. The data collected and analyzed include heart rate, skin resistance, gaze direction, hand movements, environmental data (temperature, humidity, carbon dioxide levels), game telemetry, and other parameters.

The origin of the tin used in the Bronze Age has long been one of the greatest enigmas in archaeological research. Now researchers from Heidelberg University and the Curt Engelhorn Centre for Archaeometry in Mannheim have solved part of the puzzle. Using methods of the natural sciences, they examined the tin from the second millennium BCE found at archaeological sites in Israel, Turkey, and Greece. They were able to proof that this tin in form of ingots does not come from Central Asia, as previously assumed, but from tin deposits in Europe. The findings are proof that even in the Bronze Age complex and far-reaching trade routes must have existed between Europe and the Eastern Mediterranean. Highly appreciated raw materials like tin as well as amber, glass, and copper were the driving forces of this early international trade network.

Bronze, an alloy of copper and tin, was already being produced in the Middle East, Anatolia, and the Aegean in the late fourth and third millennia BCE. Knowledge on its production spread quickly across wide swaths of the Old World. "Bronze was used to make weapons, jewellery, and all types of daily objects, justifiably bequeathing its name to an entire epoch. The origin of tin has long been an enigma in archaeological research", explains Prof. Dr Ernst Pernicka, who until his retirement worked at both the Institute for Earth Sciences of Heidelberg University as well as the Curt Engelhorn Centre for Archaeometry. "Tin objects and deposits are rare in Europe and Asia. The Eastern Mediterranean region, where some of the objects we studied originated, had practically none of its own deposits. So the raw material in this region must have been imported", explained the researcher.

Metals traded in ingot form are particularly valuable for research because questions of origin can be targeted specifically. Using lead and tin isotope data as well as trace element analysis, the Heidelberg-Mannheim research team led by Prof. Pernicka and Dr Daniel Berger examined the tin ingots found in Turkey, Israel, and Greece. This allowed them to verify that this tin really did derive from tin deposits in Europe. The tin artefacts from Israel, for example, largely match tin from Cornwall and Devon (Great Britain). "These results specifically identify the origin of tin metal for the first time and therefore give rise to new insights and questions for archaeological research", adds Dr Berger, who conducts research at the Curt Engelhorn Centre for Archaeometry.

Diversity is good, especially when it comes to antibodies. It's long been known that a gene assembly process called V(D)J recombination allows our immune system to mix and match bits of genetic code, generating new antibodies to conquer newly encountered threats. But how these gene segments come together to be spliced has been a mystery. A new study in Nature provides the answer.

Our DNA strands are organized, together with certain proteins, into a packaging called chromatin, which contains multiple loops. When a cell needs to build a particular protein, the chromatin loops bring two relatively distant DNA segments in close proximity so they can work together. Many of these loops are fixed in place, but cells can sometimes rearrange loops or make new loops when they need to -- notably, cancer cells and immune cells.

The new research, led by Frederick Alt, PhD, director of the Program in Cellular and Molecular Medicine (PCMM) at Boston Children's Hospital, shows in exquisite detail how our immune system's B cells exploit the loop formation process for the purpose of making new kinds of antibodies.

Scanning loops as they form

A pair of enzymes called RAG1 and RAG2, the researchers show, couple with mechanisms involved in making the chromatin loops to initiate the first step of V(D)J recombination -- joining the D and J segments. The RAG 1/2 complex first binds to a site on an antibody gene known as the "recombination center." As the DNA scrolls past during the process of loop formation ("extrusion"), the RAG complex scans for the D and J segments the cell wants to combine. Other factors then impede the extrusion process, pausing the scrolling DNA at the recombination center so that RAG can access the desired segments.

"The loop extrusion process is harnessed by antibody gene loci to properly present substrate gene segments to the RAG complex for V(D)J recombination," says Alt.

While many of the hard-wired chromatin loops are formed and anchored by a factor known as CTCF, the Alt lab shows that other factors are involved in dynamic situations, like antibody formation, that require new loops on the fly. The study also establishes the role of a protein called cohesin in driving the loop extrusion/RAG scanning process.

"While these findings have been made in the context of V(D)J recombination in antibody formation, they have implications for processes that could be involved in gene regulation more generally," says Alt.

A flexible schedule is one of the main advantages of freelance work. But don't rejoice in your freedom just yet: self-employment often disrupts the balance between life and work and takes up more time than traditional office work. HSE University researchers Denis Strebkov and Andrey Shevchuk investigated the downsides of independent work.

Disadvantages of the Benefits

The advantages of self-employment are well-known: you can work from home, control your workload, choose your clients, and save your resources for your own personal interests. However, in reality, this autonomy presents a paradox: 'independent' work limits a person more than it might seem.

'Freelancers often work at times when others are relaxing: in the evening, at night, on holidays, and on weekends. This disrupts one's work-life balance and negatively affects one's health, personal well-being, and social life,' say the authors of the study (link in Russian).

Why the non-standard times?

Economic need. Uncertainty about future earnings, a desire to secure a suitable income and establish a safety net.

New jobs or projects are procured online. The remote job market operates around the clock, so you need to check job postings and inquiries regularly.

Work is project-based and cyclical. The workload is uneven (tasks can pile up before deadlines), several projects may need to be fulfilled simultaneously, client activity fluctuates seasonally.

Client dependence. It is necessary to build relations with your clients -- to be constantly in touch, to meet with them, and to solve additional and urgent tasks.

Projects are combined with other activities. Freelance work gets shifted to the evening, night, or weekend if one works an additional job, studies, or is in charge of housekeeping.

Turning to the Masses

The prevalence of non-standard schedules and their impact on personal well-being was evaluated in accordance with the results of two mass polls:

Freelancer Census -- an online survey conducted on the remote work market platform FL.ru (From December 2018 -- February 2019, more than 4,200 Russian-speaking self-employed individuals from almost 40 countries participated in the survey.) The final sample was 2,400 people.

RLMS-HSE (Russian Monitoring of the Economic Situation and Public Health of the Higher School of Economics). Researchers collected data from the fall of 2017 on 12,400 people, about 5,700 of which have paid work.

A large sample size is important in this case. There is a lot of research on freelance work, but studies are usually based on observations and interviews, and quantitative estimates are clearly lacking.

Employed vs. Self-Employed

The standard work week in Russia is 40 hours. Freelancers generally both work more and less than the norm. About a third of freelancers work no more than 35 hours a week; about half work over 45 hours a week--and this latter group includes 27% of those surveyed who work 60 hours a week or more.

When the researchers compared these numbers to those of Russian workers who are not self-employed, they found significant differences.

A third (33%) of freelancers reported working almost all weekends and holidays, while another 44% said that they do this several times a month.

17% always work nights. 24% work late a few days a week.

For the general working population of Russia, it is uncommon to spend traditionally non-work hours on work-related activities:

65% never work in the evening or at night (among freelancers, this number is 10%);

34% never work on weekends and holidays (versus 2% of freelancers);

22% have worked both of the aforementioned kinds of schedules simultaneously (versus 64% of freelancers).

Nighttime Balance

Almost half (45%) of freelancers are generally satisfied with their work-life balance (i.e., the ratio of time spent on one and the other). However, nonstandard work schedules diminish workers' satisfaction.

This happens if:

There is an increase in an individual's weekend work obligations -- especially if this occurs often (at least several times a month);

An individual has to work at night at least several times a month, or worse, several times a week.

The next level of extreme work occurs when one's 'workdays' are almost every night. But here the researchers came upon some unexpected results: those who consistently worked nights were almost just as satisfied with their work-life balance as those who generally do not work nights at all.

The likely causes for this are different biorhythms ('early birds' versus 'night owls') and different views on work-life balance. 'Regular systematic work at night can be part of one's lifestyle. And if work is a joy, then time is spent on it is not against one's will and is not an aggravating factor,' explain the researchers.

Who Suffers More

The prevalence of non-standard schedules does not depend on most socio-demographic characteristics: all other things being equal, women work just as much as men, and there are no significant differences in place of residence, marital status, education, etc.

But the efforts they expend to maintain balance are not equal. Those who are least satisfied are those who:

combine freelance work with full-time employment;

are dissatisfied with their work and income;

have children.

Children are a part of traditional values. It is necessary to devote time to one's child and/or spouse or partner, regardless of how busy one is. Work-life imbalances are felt more acutely against this background. Therefore, non-standard working hours primarily decrease the well-being of women, parents, and family-oriented people.

Work-life balance satisfaction gradually decreases with age and with an increase in working time, but this dependence is non-linear:

Youth optimism diminishes: the peak of 'disappointment' occurs at about 38 years old, and then the situation improves again;

The more hours worked, the worse one's satisfaction is. However, after 87 hours a week, satisfaction picks up again. The reason, obviously, is the same as that in the case of those who prefer working nights.

'Self-employment proves to be very time-consuming. When opting for autonomy, freelancers fall into the trap of "self-exploitation and self-sale" rather than traditional "exploitation",' the researchers conclude. Therefore, they urge individuals to assess flexible employment in a balanced manner and to consider both its advantages and disadvantages.

Wherever fires are burning around the world NASA-NOAA's Suomi NPP satellite's Ozone Mapping and Profiler Suite (OMPS) can track the smoke and aerosols. On Sept. 13, 2019, data from OMPS revealed aerosols and smoke from fires over both South America and North America.

Suomi's OMPS tracks the health of the ozone layer and measures the concentration of ozone in the Earth's atmosphere and can detect aerosols. Ozone is an important molecule in the atmosphere because it partially blocks harmful ultra-violet radiation from the sun. OMPS data help scientists monitor the health of this vital protective layer.

OMPS also can be used to measure concentrations of atmospheric aerosols from dust storms and similar events as well as sulfur dioxide (SO2) from volcanic eruptions. One aerosol-related OMPS product is a value known as the "aerosol index," or AI. The AI value is related to both the thickness and height of the atmospheric aerosol layer. For most atmospheric events involving aerosols, the AI ranges from 0.0 to 5.0, with 5.0 indicating heavy concentrations of aerosols that could reduce visibilities and/or impact health.

The first OMPS was launched onboard the Suomi NPP satellite in October 2011.

An aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or anthropogenic (manmade). Examples of natural aerosols are fog, dust and geyser steam. Examples of manmade aerosols include haze (suspended particles in the lower atmosphere), particulate air pollutants and smoke.

High aerosol concentrations not only can affect climate and reduce visibility, they also can impact breathing, reproduction, the cardiovascular system, and the central nervous system, according to the U.S. Environmental Protection Agency. Since aerosols are able to remain suspended in the atmosphere and be carried along prevailing high-altitude wind streams, they can travel great distances away from their source and their effects can linger.

Fires in South America generated smoke that continues to create a long plume east into the Atlantic Ocean. Fires over western Brazil were generating aerosols at a level 2.0 on the index. Higher aerosol concentrations, as high as 4.0 were seen off the southeastern coast of Brazil as a result of the fires in the region.

In North America, Suomi NPP's OMPS detected smoke and aerosols from fires over Canada's Yukon Territories. Aerosol concentrations were very high over the Yukon fires due to a pyrocumulus event that occurred on September 11.

Pyrocumulus clouds--sometimes called "fire clouds"--are tall, cauliflower-shaped, and appear as opaque white patches hovering over darker smoke in satellite imagery. Pyrocumulus clouds are similar to cumulus clouds, but the heat that forces the air to rise (which leads to cooling and condensation of water vapor) comes from fire instead of sun-warmed ground. Under certain circumstances, pyrocumulus clouds can produce full-fledged thunderstorms, making them pyrocumulonimbus clouds.

Scientists monitor pyrocumulus clouds closely because they can inject smoke and pollutants high into the atmosphere. As pollutants are dispersed by wind, they can affect air quality over a broad area.

The image also contains a light brown area of smoke that looks like a letter "C" on its side and a low pressure system (the area of spiraled clouds) off the coast of western Canada.

Both images were created at the NASA Goddard Space Flight Center in Greenbelt, Md.

For NASA's Fire and Smoke page, visit: http://www.nasa.gov/fires

By Rob Gutro / Colin Seftor with information from https://earthdata.nasa.gov/
NASA's Goddard Space Flight Center

Leesburg, VA, September 13, 2019--Although Medicare claims data confirm the increasing role of nurse practitioners and physician assistants (NPPs) in imaging-guided procedures across the United States, according to an ahead-of-print article published in the November issue of the American Journal of Roentgenology (AJR), NPPs still rarely render diagnostic imaging services, compared with the overall number of diagnostic imaging interpretations.
When NPPs do render diagnostic imaging services, though, said services are overwhelmingly radiography and fluoroscopy.

Whereas considerable state-to-state variation exists in the rates in which NPPs render diagnostic imaging services, these rates are also uniformly low--likely due, in part, to unique scope-of-practice laws and regulations at the state level.

"At present," Emory University researcher Valeria Makeeva noted, "the near-term likelihood of NPPs appropriating substantial market share in diagnostic imaging is very low."

Utilizing 1994-2015 Medicare Physician/Supplier Procedure Summary Master Files, Makeeva and colleagues identified all diagnostic imaging services, including those billed by NPPs, and cataloged them by modality and body region. Then, using 2004-2015 Medicare Part B 5% Research Identifiable File Carrier Files, they separately assessed state-level variation in imaging services rendered by NPPs. Total and relative utilization rates were calculated annually.

Nationally, between 1994 and 2015, diagnostic imaging services increased from 339,168 to 420,172 per 100,000 Medicare beneficiaries--an increase of 24%. During this same period, diagnostic imaging services rendered by NPPs increased 14,711% (from 36 to 5332 per 100,000 beneficiaries), yet still represented a mere 0.01% and 1.27% of all imaging in 1994 and 2015, respectively.

Across all years, radiography and fluoroscopy constituted most of the NPP-billed imaging services and remained constant over time (e.g., 94% of all services billed in 1994 and 2015), representing only 0.01% and 2.1% of all Medicare radiography and fluoroscopy services. However, absolute annual service counts for NPP-billed radiography and fluoroscopy services increased from 10,899 to 1,665,929 services between 1994 and 2015.

Makeeva's team found that NPP-billed imaging was most common in South Dakota (7987 services per 100,000 beneficiaries) and Alaska (6842 services per 100,000 beneficiaries) and was least common in Hawaii (231 services per 100,000 beneficiaries) and Pennsylvania (478 services per 100,000 beneficiaries).

Acknowledging the growth in procedural, evaluation, management, and diagnostic services suggests a need for standardized, narrowly focused, highly supervised, and imaging-specific training programs for these professionals--such as those that exist for radiologic technologists aspiring to become radiologist assistants--Makeeva also noted, "our work shows the need for NPP employers to consider formally defining potential NPP roles within radiology services through NPP training programs that comport with NPP scope of practice in their specific states."

BIRMINGHAM, Ala. - The body's immune response fights against infectious disease, and it safeguards against future infections through vaccination. However, if the immune response dysfunctions and attacks the body itself, it can cause autoimmune disease. Thus, a healthy immune response balances an instant readiness to combat infecting viruses or bacteria, while maintaining benign surveillance of the body's own tissues.

A key player in the immune response is T follicular helper cells. These Tfh cells are essential in vaccination responses, but they can be harmful actors in an autoimmune disease like lupus.

Now, a preclinical study published in Science Immunology shows how the interplay of two interleukin signaling proteins, IL-6 and IL-2, affects the development of Tfh cells. This interplay may either maintain or disrupt the balancing act of the immune system. Thus, the research may help guide future disease treatment.

"We believe these findings have important therapeutic implications," said André Ballesteros-Tato, Ph.D., associate professor in the University of Alabama at Birmingham Department of Medicine's Division of Clinical Immunology and Rheumatology and leader of the research.

"For example, it is well-known that abnormal expansion of Tfh cells correlates with disease severity in systemic lupus erythematosus patients. Unfortunately, there are currently no therapies to selectively deplete Tfh cells in vivo. Based on our data, it is tempting to speculate that blockade of IL-6 with IL-6-neutralizing antibodies -- in combination with recombinant IL-2 administration -- will synergize to efficiently prevent Tfh cell responses in autoimmune patients, thereby avoiding the production of self-reactive antibodies."

Both IL-6-neutralizing antibodies and recombinant IL-2 are Food and Drug Administration-approved drugs.

"The findings in this study are quite exciting," said S. Louis Bridges, Jr., M.D., Ph.D., director of the UAB Division of Clinical Immunology and Rheumatology. "Both IL-6 and IL-2 are key molecules in immune responses and autoimmune diseases. This research helps to elucidate the complex interactions of these cytokines and how they influence Tfh cells. The novel findings in this paper may ultimately lead to better ways to treat diseases such as lupus."

Development of Tfh cells takes place this way -- Tfh cells react with antigens presented outside of B cell follicles in the lymph nodes or spleen. The activated Tfh cells then move into the follicles, where the Tfh cells interact with B cells to produce a germinal center -- a factory that multiplies and transforms B cells into high-specificity, antibody-producing cells.

The study began from an apparent paradox for the UAB researchers and colleagues in Virginia and Maryland. As Tfh cells become germinal center-Tfh cells, they need sustained T-cell receptor stimulation to maintain the germinal center-Tfh state. Yet that same stimulation is known to induce expression of the interleukin-2 receptor and production of the interleukin IL-2, which together should create a feedback loop of IL-2 signaling that is known to inhibit Tfh cells. Therefore, Ballesteros-Tato and colleagues sought to understand how Tfh cells evade this potent inhibition.

They and others previously have shown that treatment with recombinant IL-2 prevents Tfh cell responses in mice. In the Science Immunology paper, using a model of influenza infection in mice, they found that IL-6 protects Tfh cells from the deleterious effect of IL-2 by interrupting the feedback loop. This effect allows Tfh cells to receive T-cell receptor stimulation without responding to IL-2. Part of the proof of this interplay was showing that blockade of IL-6 signaling rendered Tfh cells more susceptible to IL-2-mediated depletion, at lower levels of IL-2.

The researchers found that IL-6 protection was not needed in the first week of the immune response, apparently because other immune cells that consume IL-2 are present, lowering IL-2 levels. The IL-6 protection became essential after the Tfh cells entered B cell follicles to start germinal center development. There, the IL-2 produced by Tfh cells, Ballesteros-Tato says, is not consumed, which likely lets IL-2 levels rise past a threshold that requires IL-6 protection.

The research revealed underlying mechanistic details. The researchers found that IL-6 inhibited upregulation of the IL-2 beta receptor subunit, also called CD122, by preventing association of the STAT5 transcription factor with the Il2rb gene for that receptor subunit. This allowed the germinal center-Tfh cells that received sustained T-cell receptor signaling and were producing IL-2 to circumvent the T-cell receptor/IL-2-inhibitory feedback loop because the receptor cannot function.

Altogether, these results have identified a regulatory mechanism that controls the generation of germinal center-Tfh cells. Instead of one interleukin or another controlling the response of Tfh cells in an on-off fashion, IL-6 signaling fine-tunes the threshold of IL-2 responsiveness; thus, the relative levels of the two interleukins determine the fate of the Tfh cells.

This model, Ballesteros-Tato says, clarifies previous conflicting studies regarding the role of IL-6 in controlling Tfh cell responses.

Men and ethnic minorities are less likely to wear cycle helmets and more likely to suffer from head and neck injuries in accidents, according to new research published in Brain Injury.

The study, looking at over 70,000 US cyclists' injuries from 2002-2012, found only 22% of the adult population (21% of males, 28% of females) and 12% of the younger riders who suffered these types of injuries, used helmets while riding a bicycle.

Rather unsurprisingly the research team, led by Dr Lagina Scott, a medical student in the class of 2017 of Charles R. Drew University of Medicine & Science, and the David Geffen School of Medicine at UCLA, found further evidence to clarify that wearing a helmet significantly reduced the severity of injuries, length of time spent in hospital and mortality for all cyclists.

The team analysed 10 years of data from the National Trauma Data Bank on 76,032 cyclists (81.1% male, 18.9% female).

They found that women had a higher percentage of helmet use (28.3%) compared to men (20.6%). Helmet use for Whites and Asian/Pacific Islanders was higher (27.3% and 26.6%, respectively) than for Hispanics and Blacks (7.6% and 6%, respectively).

Of those sustaining head/neck injuries in cycle accidents, men were 36% more likely to die than women, Blacks were 19% more likely to die than Whites, and Hispanics were 17% more likely to die than Whites.

Injury severity scores, length of stay in hospital and time spent in intensive care were all greater for men than women; and length of stay in hospital and time spent in intensive care were greater for Blacks, Hispanics and Asians than for Whites.

"It is perhaps not surprising that females were more likely to have worn a helmet than males when involved in an accident. It is not entirely clear, however, why males in general had higher hospital and intensive care unit stay days, and in mortality," the authors state.

"However, our analysis does show that females and males benefitted almost equally by wearing a helmet."

The research supports the protective effect of helmet use and highlights the need to educate different populations on the significant protection afforded by helmets.

The report adds: "At-risk groups may benefit from injury prevention and outreach programmes that aim to increase helmet use.

"Our findings and other research suggests that mandatory helmet laws can improve injury and mortality outcomes of bicycling accidents."

Past studies indicate that the implementation of mandatory helmet laws in some US states has decreased the severity of head injuries and bicycle-related fatalities. However, the effect of mandatory helmet use does not appear to be equal across all racial and ethnic groups.

"It remains unclear why compliance seems uneven across different races/ethnicities when helmet use is mandated by law," the authors said. "Further research is needed to answer this and other questions regarding the social determinants of helmet use and their effect on bicycle-related injury outcomes."

The highest percent of helmet use was among adults over 40 years old (31.8%) and the lowest was among and children under 17 years old (12.1%).

The authors believe that this may be down to several barriers previously highlighted by young people including being 'uncomfortable' and 'annoying,' whilst its been stated that they have a 'lack of access' and 'lack of knowledge'.

The findings of the study have several limitations. The National Trauma Data Bank is known to suffer from significant underreporting. Moreover, data on the type or design of helmet worn by participants were not available.

A cube one-fortieth the size of a human red blood cell can glow when it detects flammable gas. The nanocube, designed by chemists at the University of Tokyo, is part of a research project to develop artificial systems that mimic the complex chain of events inside living cells.

The research team has worked on the nanocube project for over a decade. A key feature of the nanocube, just two nanometers on each side, is that it puts itself together, attempting to mimic the way proteins and DNA put themselves together in living cells.

Mimicking life

"People automatically think about devices when we talk about sensors. But there are many examples of natural sensors in the body," said Professor Shuichi Hiraoka, the lead researcher on the project from the University of Tokyo's Department of Basic Science.

The basic chain of events in a cell to detect and report some signal has three steps: 1) A receptor detects the target molecule, 2) the receptor sends a signal to the reporter and 3) the reporter transmits the signal elsewhere in the cell.

The glowing nanocube simplifies the system because it is both the receptor (the inside of the cube) and the reporter (the glow).

"This way, we avoid the problem of transferring information from the receptor to the reporter," explained Hiraoka.

Nanocube sensors fully envelop the molecules they contain, meaning they could be especially useful for distinguishing between molecules that are shaped like simple chains of different lengths (alkanes) without unique functional groups.

Glowing with gas

The latest analysis reveals that the nanocubes glow blue under ultraviolet (UV) light when filled with liquefied petroleum gas (LPG), a type of flammable gas.

The chemical that the cube is made from is a white powder when dry, but when mixed in water, six gear- or snowflake-shaped molecules automatically connect to form the cubes. The natural glow, or fluorescence, of the nanocubes is a balance of two competing physical characteristics of those molecules: The glow is limited when the molecules are stacked like pancakes, but is enhanced when the molecules are locked in place and slightly stretched apart from each other.

Three molecules come together at each corner of the cube, so their edges are "stacked" together, limiting the glow. When the cube fills with gas, the corners bulge slightly and that stretch enhances the glow.

Nanocube gas detectors

The researchers built a cheap, simple gas detector using only the nanocubes, a common UV light and a fluorescent light detector.

The nanocubes are as sensitive as any current gas detector, meaning they could detect very low amounts of LPG.

However, the nanocubes are incredibly specific to LPG. They do not detect other similar types of flammable gas, such as methane (natural gas) or carbon dioxide (CO2). This specificity likely occurs because exactly three molecules of LPG slot in like blocks in the game Tetris for a perfect fit inside the nanocube.

Common gas detectors do not have this specificity and will sound an alarm for any type of dangerous gas.

"The fact that common sensors cannot distinguish these similar gases is really no problem, because they are all dangerous to us," said Hiraoka.

Rather than to design a new gas detector, the researchers' true goal is to mimic the complex chain of events to detect and report signals in living cells.

Researchers are planning additional projects to alter the building blocks of the nanocubes so that the cubes can detect different molecules and report different signals.

Osaka, Japan - Researchers from Osaka University have made the striking discovery that multidrug-resistant bacteria may have been around longer than we thought.

In findings published this month in Communications Biology, the researchers investigated the evolutionary relationships among hundreds of RND-type efflux pumps—specialized proteins that pump multiple different types of antibiotics out of a bacterial cell, making it multidrug resistant.

"Interestingly, we found that RND efflux pump AcrB from H. influenzae was relatively ancient but exported the same antibiotics as its more evolved counterpart from Escherichia coli," explains lead author of the study Martijn Zwama. "What it couldn't do well was export bile salts, which are not something that H. influenzae encounters in its normal habitat but are common components of the gut, where E. coli resides."

While this pointed to evolution of the pumps in their natural environments, it also suggested that multidrug recognition is an ancient trait. This is an important distinction because most bacteria acquire resistance genes or mutations in the face of selective pressure from the environment.

But while AcrB protects H. influenzae from several difference classes of antibiotics, the pathogen remains susceptible to β-lactams and novobiocin, something that researchers have previously not been able to explain.

"Bacterial membranes contain channels that selectively let different substrates into the cell," says co-author Akihito Yamaguchi. "We found that in H. influenzae, one of these channels, OmpP2, was slightly leaky. This meant that some of the smaller drugs pumped out of the cell by AcrB could seep back inside, where they went to work killing the bacterium."

Multidrug-resistant bacteria have devastating—and often lethal—effects in infected patients. And with new strains constantly emerging, these super pathogens are arguably the biggest threat to human health today. Therefore, drugs targeting efflux pumps have been developed. However, the researchers found that these drugs had no effect on H. influenzae.

"Efflux pump inhibitors bind to a phenylalanine-rich pocket in AcrB. Unfortunately, these drugs were designed to target the more evolved proteins in species like E. coli," explains study corresponding author Professor Kunihiko Nishino. "Because H. influenzae AcrB is more ancient, we found that it does not contain the same pocket configuration and is therefore unaffected by the efflux pump inhibitors."

Uncovering these evolutionary differences has shown that a "one size fits all" approach is not suitable to address RND-type efflux pumps. This research provides a more accurate picture of the evolution and mechanism of multidrug efflux systems, which will assist the development of new antibiotics to more effectively target specific multidrug-resistant pathogens.