Culture

For allergy sufferers, the pollination period is a tough time, whereas for plants it is the opportunity to reproduce: in addition to the wind, insects, in particular, carry the pollen from one flower to another to pollinate them. During this transport, the pollen must repeatedly attach to and detach from different surfaces. To date, the underlying adhesive mechanisms have hardly been studied so far. Now, scientists from the Zoological Institute at Kiel University have discovered that the mechanisms are far more complex than previously assumed. They differ depending on the duration of the contact and the microstructure of the surfaces. In their study presented in the current issue of the Journal of the Royal Society Interface, they found a unique pollen gripping mechanism on the receptive female part of plants for the first time. The results could provide important knowledge for the transport of medicinal substances, and also - in light of the alarming decline in insect populations - for the development of alternative strategies in agriculture and food production.

Pollen: an all-round adhesive talent

Itchy nose, red eyes, constant sneezing - materials scientist Shuto Ito suffered from a severe pollen allergy. To learn more about the process of pollen dispersal he left his hometown in Japan to study the adhesive properties of pollen under Professor Stanislav Gorb at Kiel University. Bionics researcher Gorb and his working group "Functional Morphology and Biomechanics" investigate the special abilities of plants and animals, and how these can be imitated artificially.

"If pollen is transported by insects from flower to flower, it encounters three different types of surfaces to which it must attach itself and then detach again. We want to find out which adhesive mechanisms enable this," explained Gorb. Doctoral researcher Ito investigates these mechanisms using as a model species Hypochaeris radicata, also known as common cat's-ear (or false dandelion). This species within the family of the composite plants blooms from spring to late autumn in the entire northern hemisphere. As with many other plants, the pollen on their yellow flowers is covered with an oily substance known as pollenkitt. "Until now, scientists believed that pollenkitt has a central adhesive function. But we have found out that under certain conditions it behaves in exactly the opposite way. We must consider the adhesive mechanisms in a much more differentiated manner," Ito summarised the findings thus far. Accordingly, pollen adhesion is influenced by a complex interplay of the age of the pollen, the humidity and the respective surfaces for adhesion.

Examining the starting and ending points of the pollen's journey

In their current study, the scientists concentrated on the two parts of the plant, which are most important for the pollination. They represent the starting and ending points of the pollination: on the style of a flower, the pollen grain is presented before it is rubbed off by an insect. On the upper end of the style, the incoming pollen grains land on the stigma.

With an atomic force microscope, the scientists measured how strongly the pollen adhered to both the style and the stigma in Hypochaeris radicata. They discovered that both parts of the plant have very distinct adhesive properties, which change during the course of the pollination. Thus, the pollen adhesion on the stigma increases, while that on the style is rather restrained. The adhesion force of fresh pollen on the stigmatic surfaces exhibited a dramatic increase over the contact time of 180 seconds by a factor of 11.9, while the adhesion force of fresh pollen on the stylar surfaces yielded an increase only by a factor of 2.7.

Optimal adjustment during the course of evolution

"We assume that during the course of evolution, the two parts of the plant have developed different functions, in order to optimize the pollination process," explained Ito. If the adhesion increased on the style as the starting point of pollination, then the pollen grains could not be detached. In contrast, the stigma has increased its adhesive properties and keeps hold of pollen grains once they come into contact with it. "The newly found pollen gripping mechanism on the stigma is likely to assure the reproduction of plants by anchoring pollen on the stigma until fertilization occurs" Ito continued.

The scientists suggest that the different properties of the two parts of the plant are due to their different surface structures and the presence or absence of secreted liquid on the surface, which can be seen at the resolution of an electron microscope. They examined shock frozen samples of the plants with a Cryo scanning electron microscope. In this condition, the samples retain their original structure, and even fluids such as the secreted liquid on the stigma can be observed in high-resolution images.

New insights into coating processes and transporting medicinal substances possible

"If we can discover the mechanisms by which such interactions of microparticles and surfaces could be controlled, we could potentially draw conclusions for coating and printing processes, the transport of medicinal substances, or the treatment of respiratory diseases," suspects Gorb. And maybe one day special filters for pollen allergy sufferers.

Bottom Line: The U.S. Preventive Services Task Force (USPSTF) is broadening its recommendation on screening for potentially harmful mutations of the breast cancer susceptibility BRCA1/2 genes, which are associated with increased risk of certain cancers. The USPSTF now recommends primary care clinicians assess risk in women with a personal or family history of breast, ovarian, fallopian tube, or peritoneal (tissue lining the abdominal cavity) cancer or those who have an ancestry associated with BRCA1/2 mutations. Women with a positive result on that risk assessment should receive genetic counseling and, if indicated after counseling, genetic testing. The USPSTF recommends against routine risk assessment, genetic counseling, or genetic testing for women whose personal or family history or ancestry is not associated with BRCA1/2 mutations.

(doi:10.1001/jama.2019.10987)

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

Note: More information about the U.S. Preventive Services Task Force, its process, and its recommendations can be found on the newsroom page of its website.

Heavy cigarette smokers with at least a 20 pack-year smoking history can reduce their risk of cardiovascular disease (CVD) by 39% within five years if they quit, according to a study published today in the Journal of the American Medical Association (JAMA).

But it takes at least five to 10 years, and perhaps up to 25 years after quitting, for CVD risk to become as low as that of a similar person who has never smoked.

"Previous studies have shown the association between quitting and reduced CVD risk," said lead author, Meredith Duncan, MA, who led the analyses for the Division of Cardiovascular Medicine at Vanderbilt University Medical Center. "But the current Atherosclerotic CVD Risk Calculator, which is routinely used in clinical practice, considers former smokers' risk to be similar to that of never smokers after five years of cessation, which is not consistent with these findings."

Cigarette smoking is responsible for 20% of CVD deaths in the United States, the study notes.

Researchers used data from the Framingham Heart Study, a longitudinal study of men and women from Framingham, Massachusetts, which began enrollment in 1948 and now includes their children and grandchildren, as well as multiethnic cohorts.

The study used prospective data from 1954 through 2014 from 8,770 participants -- 3,805 from the Original cohort and 4,965 from the Offspring cohort -- to determine the effect of lifetime smoking and smoking cessation on the risk of CVD, which includes myocardial infarction, stroke, CVD death and heart failure.

"The Framingham Heart Study provides particularly robust data on lifetime smoking history," added Duncan. "Our team leveraged this unique opportunity to document what happens to CVD risk after quitting smoking relative to people who continued to smoke and to those who never smoked."

Senior author Hilary Tindle, MD, MPH, medical director of the VUMC Tobacco Treatment Service and founding director of the Vanderbilt Center for Tobacco Addiction and Lifestyle (ViTAL), urges smokers to act on these study results by putting out their cigarettes.

"The cardiovascular system begins to heal relatively quickly after quitting smoking, even for people who have smoked heavily over decades," Tindle said. "Full recovery could take years, so now is a great time to quit smoking and take other steps toward heart health."

Chinese cabbage is part of a crop family that must be exposed to cold temperatures for a particular period of time in order to flower. Scientists have succeeded in comprehensively identifying the long noncoding ribonucleic acids (IncRNAs) that are expressed when Chinese cabbage is temporarily exposed to cold temperatures for four weeks. LncRNAs that are known to be involved in responding to cold in Arabidopsis thaliana do not exist in Chinese cabbage, which suggests that Chinese cabbage has its own independent mechanism for flowering.

The research team was led by Namiko Nishida (Kobe University Graduate School of Agricultural Science) and Daniel Shea (Niigata University Graduate School of Science and Technology). The team also included Associate Professor Ryo Fujimoto (Kobe University Graduate School of Agricultural Science), Professor Keiichi Okazaki (Niigata University Graduate School of Science and Technology), Team Leader Motoaki Seki (RIKEN Center for Sustainable Resource Science), members of Japan's National Agriculture and Food Research Organization (NARO) and Australia's Commonwealth Scientific and Industrial Research Organisation. The findings were published on June 26 in the online edition of Scientific Reports.

Non-coding RNAs lack the information needed to create proteins. These noncoding RNAs are classified into small RNAs (around 20 nucleotides long) and long noncoding RNAs (IncRNAs, over 200 nucleotides long). LncRNAs are expressed in most plants, with tens of thousands known to be expressed in the model plant A. thaliana.

LncRNAs have been linked to the phenomenon of vernalization: when plants need to be exposed to a period of cold treatment in order to flower. This phenomenon can be seen in many subspecies of Brassica rapa L. including the Chinese cabbage, which grows during winter to bloom in spring (Figure 1).

The research team extracted total RNAs from Chinese cabbage leaves cultivated for two weeks at 22°C and Chinese cabbage leaves cultivated at room temperature for two weeks, then at a low temperature (4°C) for a further four weeks. Using RNA-sequencing, they obtained enough information to identify the changes in the expression of IncRNAs after exposure to low temperatures.

When the team investigated the mRNAs (messenger RNAs) expression patterns induced by low temperatures whose transcription domains overlapped with incRNAs (intronic RNAs, a type of IncRNA) and NATs (natural antisense transcripts, another type of IncRNA), they found similar expression patterns but a strong association to vernalization was not found. However, they found combinations of mRNA and NATs that showed the same altered expression under low temperatures (Figure 2), suggesting that NATs are connected to changes in mRNA expression under cold treatment.

The team searched for the existence of IncRNAs whose expression is induced by cold treatment, focusing on the BrFLC loci. One NAT called BrFLC2as showed similar structure and expression patterns to COOLAIR (a key IncRNA of A. thaliana), but these similarities were not found in BrFLC1, BrFLC3 or BrFLC5 (Figure 3). In all four BrFLC types, the IncRNAs COLDAIR and COOLWRAP known to recruit the PRC2 complex in A. thaliana was not identified in Chinese cabbage. Their results suggest that for Chinese cabbage exposed to low temperatures, the PRC2 complex may be recruited to the FLC locus based on a different mechanism from A. thaliana.

From these findings we now know that IncRNA expression is not induced in Chinese cabbage from the FLC locus, suggesting that it follows a different flowering mechanism from the model in A. thaliana. The next step is to reveal how the PRC2 complex is recruited to the FLC locus under cold treatment. Revealing the full vernalization mechanism via FLC genes could contribute to selective breeding of Chinese cabbage.

Ann Arbor, August 20, 2019 - A new study in the American Journal of Preventive Medicine, published by Elsevier, found that the prevalence of depression, cannabis use, and alcohol abuse increased among former smokers from 2005 to 2016 in the United States. Therefore, increases in these risk factors for relapse among former smokers could threaten progress in reducing the prevalence of cigarette use.

"It's good news that as tobacco control efforts have been successful at reducing smoking, the proportion of former smokers among the US population is increasing. However, as our study demonstrates, more of them are now suffering from depression and engaging in problematic substance use," said lead investigator Renee D. Goodwin, PhD, Institute for Implementation Science in Population Health, The City University of New York; Department of Epidemiology, Mailman School of Public Health, Columbia University; and Department of Epidemiology and Biostatistics, Graduate School of Public Health and Health Policy, The City University of New York, New York, NY, USA.

Conducted in 2018-9, the study investigated the prevalence of depression, cannabis use, and alcohol misuse among former smokers ages 18 and older in the US from 2005 to 2016. Data were drawn from the National Survey on Drug Use and Health, an annual, nationally representative cross-sectional study. More than 67,000 individuals, aged 18 and over, participated in the study. It is the first national US study to focus on the prevalence and time trends of depression, marijuana use, and problematic alcohol use among former smokers.

During the study period, the incidence of major depression increased from 4.88 percent to 6.04 percent, cannabis use during the previous year rose from 5.35 percent to 10.09 percent, and alcohol binge drinking during the previous month went up from 17.22 percent to 22.33 percent among former smokers.

The results show that the profile of former smokers has changed over the study period. An increasing percentage of the US population who were ever smokers, no longer smoke (49.7 percent in 2016, compared to 44.4 percent in 2002). Former smokers are slightly more likely to be male than female, married, and of non-Hispanic white ethnicity. In 2016 compared to 2002, former smokers were more likely to be older than 65, never married, have some college education, and incomes over $75 thousand a year. More than half of them had also quit smoking for three years or more. Factors that may have affected the results are the increasing legalization, decreasing perception of risk associated with use, and reduced stigma of cannabis, which may sometimes be used by smokers trying to quit tobacco. However, the investigators note that when former smokers use it, they increase their likelihood of returning to tobacco.

"Because previous research has demonstrated that these factors put former smokers at greater risk of relapsing with tobacco (and relapse is a risk that lingers for decades), our study should signal an alarm for public health leaders and healthcare providers. The findings represent a looming threat to the progress that has been made in reducing the prevalence of cigarette use," Dr. Goodwin cautioned.

Dr. Goodwin noted that the findings should have bearing on ongoing tobacco control policy decisions, "Since it has been shown that depression and substance use may compromise abstinence, anyone designing community-based public information campaigns and engaged in clinical interactions with former smokers should be made aware that modifiable predictors of relapse are increasing among former smokers. As such, screening for these issues and referral to treatment should be high priorities. These are important steps for assuring growing and sustained abstinence among the US population, a trend with significant health and societal benefits."

Researchers in Umeå, Sweden, have presented a model that explains why memory deteriorates as the body ages. With age, the brain receives an increased load from the heart's beating as the body's large arteries stiffen over the years, causing damage to the smallest blood vessels in the brain.

The fact that human memory is deteriorating with increasing age is something that most people experience sooner or later, even among those who avoid diseases such as Alzheimer's. Similarly, a connection between the ageing of the brain and the body is well known. However, the exact nature of this association is not known.

"We suggest a chain of events on how the ageing of the brain and vessels are related," says Lars Nyberg, professor at Umeå University.

What Umeå researchers Lars Nyberg and Anders Wåhlin have created is an explanatory model that starts with the heartbeat, and carries through the largest arteries in the body all the way to the finest vessels in the brain. An important feature of the model is that it provides a rationale why some cognitive processes may be particularly at risk for the proposed mechanism.

As the human body ages, large arteries, such as the aorta, stiffen and lose a large portion of their ability to absorb the pressure increase generated as the heart ejects blood into the arteries. Such pressure pulsatility is instead transmitted to smaller blood vessels, for example those in the brain. The smallest blood vessels in the brain, the capillaries, are subjected to an increased stress that causes damage to cells within and surrounding the capillary walls. These cells are important in the regulation of the capillary blood flow. If the smallest blood vessels are damaged, this is detrimental to the ability to increase the blood supply to the brain when coping with demanding cognitive processes.

According to the researchers' model, the hippocampus in the brain is particularly vulnerable. The structure in that part of the brain is important for the episodic memory, that is, the ability to remember events from the past. The vulnerability of the hippocampus relates to the fact that it is located close to the large vessels and thus is exposed to the increased load early in the chain. In a young and healthy person, the pulsations are soft, but in an ageing person the pulsations can be so powerful that they affect the brain tissue and can damage the blood supply to memory processes.

The Umeå researchers' model is based on a number of previous studies from the last five years.

"We have laid the puzzle of current and verified research in different fields to a broader and more detailed picture of the course of events. It will form a starting point for future research to gain a better understanding and, in the long term, researchers may also find solutions to slow down the process," says Anders Wåhlin.

If you lose sleep over the number of likes on your Instagram account, you might want to think twice before posting that selfie.

That's the main takeaway from a new study in the Journal of Research in Personality by Washington State University psychologists.

The scientists conducted a novel experiment with hundreds of actual Instagram users to determine if there are certain types of self-image posts that cause others to make snap judgements about the user's personality.

Their work shows that individuals who post a lot of selfies are almost uniformly viewed as less likeable, less successful, more insecure and less open to new experiences than individuals who share a greater number of posed photos taken by someone else. Basically, selfie versus posie.

"Even when two feeds had similar content, such as depictions of achievement or travel, feelings about the person who posted selfies were negative and feelings about the person who posted posies were positive," said Chris Barry, WSU professor of psychology and lead author of the study. "It shows there are certain visual cues, independent of context, that elicit either a positive or negative response on social media."

Barry began researching possible links between Instagram activity and personality traits around five years ago. At the time, the idea that people who take lots of selfies are probably narcissists was front and center in the pop culture world.

Barry decided to put the popular theory to the test. He conducted two studies investigating potential links between posting lots of selfies on Instagram and a narcissistic personality.

Somewhat surprisingly, the research was inconclusive.

"We just weren't finding anything," Barry said. "That got us thinking that while posts on social media might not be indicative of the poster's personality, other people might think they are. So, we decided to design another study to investigate."

A novel experiment

Barry, along with WSU psychology students and collaborators from the University of Southern Mississippi analyzed data from two groups of students for the study. The first group consisted of 30 undergraduates from a public university in the southern United States.

The participants were asked to complete a personality questionnaire and agreed to let the researchers use their 30 most recent Instagram posts for the experiment.

The posts were coded based on whether they were selfies or posies as well as what was depicted in each image, such as physical appearance, affiliation with others, events, activities or accomplishments.

The second group of students consisted of 119 undergraduates from a university in the northwestern United States. This group was asked to rate the Instagram profiles of the first group on 13 attributes such as self-absorption, low self-esteem, extraversion and success using only the images from those profiles.

Barry's team then analyzed the data to determine if there were visual cues in the first group of students' photos that elicited consistent personality ratings from the second group.

They found that the students who posted more posies were viewed as being relatively higher in self-esteem, more adventurous, less lonely, more outgoing, more dependable, more successful and having the potential for being a good friend while the reverse was true for students with a greater number of selfies on their feed.

Personality ratings for selfies with a physical appearance theme, such as flexing in the mirror, were particularly negative, the researchers found.

Other interesting findings from the study included that students in the first group who were rated by the second group as highly self-absorbed tended to have more Instagram followers and followed more users.

The researchers also found the older the study participants in the second group were, the more they tended to rate profiles negatively in terms of success, consideration of others, openness to trying new things and likeability.

"One of the noteworthy things about this study is that none of these students knew each other or were aware of the Instagram patterns or number of followers of the people they were viewing," Barry said.

The researchers have several theories to explain their results.

The generally positive reactions to posies may be due to the fact that the photos appear more natural, similar to how the observer would see the poster in real life.

Another explanation is that selfies were far less frequently posted than posies and seeing one could signal something strange or unusual about the poster.

"While there may be a variety of motives behind why people post self-images to Instagram, how those photos are perceived appears to follow a more consistent pattern," Barry said. "While the findings of this study are just a small piece of the puzzle, they may be important to keep in mind before you make that next post."

Site-directed spin labelling (SDSL) used in combination with electron paramagnetic resonance (EPR) spectroscopy has been a tried and trusted technique for elucidating the structure, function and dynamics of proteins and protein complexes. Nitroxide-based spin labels are among the most popular and best established ones because they are small, non-disturbing and exhibit excellent spectroscopic properties. "Ideal spin labelling procedures exhibit high reaction rates and selectivity", explains Professor Malte Drescher, Professor for Spectroscopy of Complex Systems at the University of Konstanz's Department of Chemistry and main author on the study alongside Professor Valentin Wittmann, who specializes in organic synthesis.

"Achieving high reactivity and high selectivity both at the same time can be a problem", continues Drescher. "Conventional spin labels based, for instance, on Gadolinium(III) or trityl, display either very broad spectra and low modulation depths or very narrow spectra that are unsuitable for the kinds of experiments that we want to conduct". A new study published by Drescher, Wittmann and their team of University of Konstanz chemists, which was published online in the journal ChemBioChem Communications on 14 August 2019, introduces a new approach for labelling proteins that features nitroxide-based spin labels and genetically encoded noncanonical amino acids (ncAAs) as targets for SDSL.

"Nitroxides provide ideal spectral width and access to dynamic information", says Anandi Kugele, a doctoral researcher at the Konstanz Research School Chemical Biology (KoRS-CB) and first author on the study, who received a prestigious travel grant from the National High Magnetic Field Laboratory to present the results at the 2019 Rocky Mountain Conference on Magnetic Resonance in Denver, Colorado (USA). "Traditional nitroxide-based labels have limited redox stability, which is a drawback for in-cell applications. The challenge for us was to increase nitroxide stability and thus to adapt nitroxide-based spin labels for future routine in vivo use". To that end, the researchers developed a new spin label that can be attached to proteins by means of inverse-electron-demand Diels-Alder (DAinv) cycloaddition to genetically encoded ncAAs, a method which has proven suitable to a broad range of in vitro and in vivo applications. To achieve nitroxide stability, the researchers further used a protection strategy based on photoremovable protecting groups, which are known to protect nitroxides and to release them as needed.

The new spin label - termed photoactivatable nitroxide for DAinv reaction, or PaNDA for short - is water soluble, EPR-active and deprotection-efficient as both in vitro and in lysate tests with the two model proteins green fluorescent protein (GFP) and Escherichia coli oxidoreductase thioredoxin (TRX), which is found in virtually all known organisms, suggest. "We do need to improve on the method used to deliver the PaNDA spin label to cells and to test labelling and deprotection efficiencies inside the cell, amongst other things", concludes Malte Drescher: "But our research clearly demonstrates that, in principle, the PaNDA label can be used for EPR measurements in challenging biological environments, including the inside of cells. Our tests with E. coli lysate are very promising in this respect. This will open up a whole new range of opportunities for the study of proteins by means of EPR spectroscopy".

Washington, DC - August 20, 2019 - Most types of Escherichia coli are harmless, but the ones that aren't can cause severe life-threatening diarrhea. These problematic bacteria launch infections by inducing intestinal cells to form tiny structures, called pedestals, that anchor the pathogens in place and help the colonies grow.

This week in mBio, microbiologists describe an Achilles heel for disabling pedestal formation. Lab experiments on enteropathogenic and enterohemorrhagic E. Coli (EPEC and EHEC) showed that when the pathogens were prevented from injecting a protein called EspG into intestinal hosts, the hosts were slower and less effective in producing pedestals that fixed the bacteria in place. Further investigations revealed the cellular pathways hijacked by EspG.

The findings can help reveal the mechanics of infection and suggest new avenues of treatment, said microbiologist and study co-leader Peter Hume, Ph.D, at the University of Cambridge in the United Kingdom.

"By learning how these pathways work, we think we can develop new ways of interfering with the infection process," he said.

Worldwide, more than 500,000 children die every year from diarrheal diseases, and pathogenic strains of E. Coli are among the most common causes, according to the World Health Organizations. But treating these infections can be tricky. Using antibiotics to treat a person with EHEC, for example, can trigger the bacteria to release Shiga toxin, which can lead to a life-threatening infection similar to sepsis. That means health care providers need treatments other than antimicrobials to keep these infections in check, Hume said.

Researchers have long known that pathogenic E. coli injects its host with a variety of proteins, including EspG. Until now, however, those interactions have been linked only to other biochemical functions. "People had tried to find a link to pedestals before, but they hadn't found one," said Hume, whose work focuses on how bacterial pathogens affect the cytoskeletons of host cells. The current study was carried out in the lab of Vassilis Koronakis, by Hume in collaboration with Cambridge colleagues Vikash Singh and Anthony Davidson.

Previously, the researchers studied the effects of EspG on macrophages, and those findings suggested the protein may have an overlooked role in pedestal formation with intestinal hosts.

For the current study, they infected one group of Hap1 cells with wild-type EHEC and EPEC, and infected another with the same types of E. Coli, but lacking the genes responsible for producing EspG. Using fluorescence microscopy, the researchers studied the results. The cells infected by E. Coli lacking EspG took longer to produce pedestals the those by wild-type strains, and what pedestals were produced were shorter.

Follow up experiments revealed that the EspG protein hijacks the host cell by scavenging an active enzyme called PAK. Although previous work has shown a link between EspG and PAK, the new study is the first to connect the two to the formation of pedestals.

That connection may help researchers studying other diseases, as well. PAK has been implicated in some cancers, and other studies have shown that some viruses -- including HIV -- can activate it.

"This study may well have implications with other pathogens that manipulate the same pathways," Hume said.

Cold water released from Lake Shasta into the Sacramento River to benefit endangered salmon can be detrimental to young green sturgeon, a threatened species adapted to warmer water. But scientists at UC Santa Cruz and the National Marine Fisheries Service have found a way to minimize this apparent conflict through a water management strategy that benefits both species, while also meeting the needs of agricultural water users downstream.

Releases of cold water during the spring and summer create favorable spawning conditions in the Sacramento River for the endangered winter-run chinook salmon, which were cut off from their historical spawning grounds at higher elevations by the construction of Shasta Dam. Salmon eggs require cold water temperatures to survive, but juvenile green sturgeon need the lower flows and warmer temperatures typical of the main stem of the Sacramento River to grow and thrive.

The researchers used statistical modeling to see if there is an optimal management scenario that can meet the needs of both species along with those of downstream water users. Their results, published August 20 in the Journal of Applied Ecology, show that dam releases can be managed to achieve all three objectives in all but the most severe drought years.

"It's a win-win-win here in the sense that we're not giving up anything to get an improvement for the green sturgeon," said Eric Palkovacs, associate professor of ecology and evolutionary biology at UC Santa Cruz and senior author of the paper. "Currently, the primary management objectives are keeping it cold for the salmon eggs and delivering enough water downstream. As a result, we've been refrigerating the river in regions where historically the green sturgeon have been spawning."

First author Liam Zarri conducted the study for his UCSC master's thesis, working with Palkovacs and coauthors Eric Danner and Miles Daniels at the National Marine Fisheries Service laboratory in Santa Cruz. Zarri found that discharge rates and water temperatures strongly influence the body condition of larval green sturgeon. In years with high discharges of cold water, egg survival for winter-run chinook salmon was high but the condition of juvenile green sturgeon was poor. In drought years, however, with low flows and warmer water, green sturgeon did well while salmon egg survival was low. The sturgeon larvae seem to be especially sensitive to high discharges, which affect their swimming ability and availability of prey.

The key to meeting the needs of both species, Zarri said, is that they spawn at slightly different times of the year. "We're able to suggest a management scenario which uses the differential timing of spawning in these two species. When they overlap, our model gives us the ideal temperature and flow for when both species are present," he said.

Zarri noted that the dam releases can draw either cold water from the bottom of the lake or warmer water from closer to the surface. Under the optimal management scenario proposed in the paper, low flows of warmer water can be released early in the season (April and May) when only green sturgeon are spawning and demand for water for agriculture has not yet ramped up. Late in the season (July to November), high flows of cold water can be released to benefit salmon and meet agricultural water needs.

The overlap period in June and early July, when both salmon and sturgeon are present in the part of the river most affected by the dam releases, is more complicated. That's where the statistical modeling approach, which takes into account the needs of both species, provides the ideal conditions of temperature and water flow that dam managers can aim for to ensure that the river is not too warm for salmon or too cold and fast for sturgeon.

"Under the current management, there is quite a long period of cold water releases starting very early in the season before the chinook salmon have really started showing up in earnest. We're saying that you can wait until the green sturgeon have matured and moved out of the system," Palkovacs said. "That has a side benefit in drought years, when limiting those early releases saves water for later in the year when it's more valuable, both for salmon and for downstream water demand."

Palkovacs noted that other native species in the river, including spring and fall runs of salmon, are probably also being affected by the cold water releases. At this point, however, the researchers did not have enough information about other species to include them in their analysis.

Crude oil and gas naturally escape from the seabed in many places known as "seeps". There, these hydrocarbons move up from source rocks through fractures and sediments towards the surface, where they leak out of the ground and sustain a diversity of densely populated habitats in the dark ocean. A large part of the hydrocarbons, primarily alkanes, is already degraded before it reaches the sediment surface. Even deep down in the sediment, where no oxygen exists, it provides an important energy source for subsurface microorganisms, amongst them some of the so-called archaea.

These archaea were good for many surprises in recent years. Now a study led by scientists from the Max Planck Institute for Marine Microbiology in Bremen, Germany, and the MARUM, Centre for Marine Environmental Sciences, provides environmental information, genomes and first images of a microbe that has the potential to transform long-chain hydrocarbons to methane. Their results are published in the journal mBio.

Splitting oil into methane and carbon dioxide

This microbe, an archaeon named Methanoliparia, transforms the hydrocarbons by a process called alkane disproportionation: It splits the oil into methane (CH4) and carbon dioxide (CO2). Previously, this transformation was thought to require a complex partnership between two kinds of organisms, archaea and bacteria. Here the team from Max Planck Institute for Marine Microbiology and MARUM presents evidence for a different solution. "This is the first time we get to see a microbe that has the potential to degrade oil to methane all by itself", first-author Rafael Laso-Pérez explains.

During a cruise in the Gulf of Mexico, the scientists collected sediment samples from the Chapopote Knoll, an oil and gas seep, 3000 m deep in the ocean. Back in the lab in Bremen, they carried out genomic analyses that revealed that Methanoliparia is equipped with novel enzymes to use the quite unreactive oil without having oxygen at hand. "The new organism, Methanoliparia, is kind of a composite being", says Gunter Wegener, the initiator and senior author of this study. "Some of its relatives are multi-carbon hydrocarbon-degrading archaea, others are the long-known own methanogens that form methane as metabolic product." With the combined enzymatic tools of both relatives, Methanoliparia activates and degrades the oil but forms methane as final product. Moreover, the visualization of the organisms supports the proposed mechanism: "Microscopy shows that Methanoliparia cells attach to oil droplets. We did not find any hints that it requires bacteria or other archaea as partners", Wegener continues.

Very frequent and globally distributed

Methanogenic microorganisms have been important for the earth's climate through time as their metabolic product, methane, is an important greenhouse gas that is 25 times more potent than carbon dioxide. Thus, Laso-Pérez and his colleagues where also interested to find out about how widespread this novel organism is. "We scanned DNA-libraries and found that Methanoliparia is frequently detected in oil reservoirs - and only in oil reservoirs - all over the oceans. Thus, this organism could be a key agent in the transformation of long-chain hydrocarbons to methane", says Laso-Pérez.

Thus, the scientists next want to dig deeper into the secret life of this microbe. "Now we have the genomic evidence and pictures about the wide distribution and surprising potential of Methanoliparia. But we can't yet grow them in the lab. That will be the next step to take. It will enable us to investigate many more exciting details", Wegener explains. "For example, whether it is possible to reverse the process, which would ultimately allow us to transform a greenhouse gas into fuel. "

ITHACA, N.Y. - Cornell University food scientists have created a new low-calorie 'butter' spread that consists mostly of water. A tablespoon of this low-calorie spread has 2.8 grams of fat and 25.2 calories. Butter, on the other hand, which is 84% fat and about 16% water, has about 11 grams of fat and nearly 100 calories.

They figured out a new process to emulsify a large amount of water with miniscule drops of vegetable oil and milk fat to mimic butter, at approximately one-fourth the calories of real butter and without artificial stabilizers.

"Imagine 80% water in 20% oil and we create something with the consistency of butter, with the mouth feel of butter and creaminess of butter," said food science professor and senior author Alireza Abbaspourrad.

Emulsifying water and oil is nothing new, said Abbaspourrad, but by using high-internal phase emulsions (HIPE), "we keep adding water to that oil until the final composition is 80% water and 20% oil."

The demand for low-fat, high-protein products has rapidly increased due to consumers' growing health awareness, said lead author Michelle C. Lee, a doctoral candidate in Abbaspourrad's research group.

"Since the HIPE technology features high water-to-oil ratios - while simultaneously delivering unique texture and functionality - it can play a role in providing healthier solutions for consumers," Lee said.

Abbaspourrad said food chemists can adjust for taste, preferences and health.

"We can add milk protein or plant-based protein, and since the water acts like a carrier, we can adjust for nutrition and load it with vitamins or add flavors," he said. "Essentially, we can create something that makes it feel like butter - and instead of seeing a lot of saturated fat, this has minute amounts. It's a completely different formulation."

Gastroesophageal reflux (GERD) is associated with chronic, painful temporomandibular disorder -- pain in the temporomandibular joint -- and anxiety and poor sleep contribute to this association, according to a study in CMAJ (Canadian Medical Association Journal) http://www.cmaj.ca/lookup/doi/10.1503/cmaj.181535.

Pain from temporomandibular disorder (TMD) affects about 13% of Canada's population. Reflux is an uncomfortable condition in which stomach contents are regurgitated into the throat. Evidence indicates that anxiety, somatization and depression are linked to GERD.

Researchers from China and the United States looked at data on 1522 patients with chronic TMD, of whom 69% (1048) were women, to understand the relationship between chronic TMD and GERD and to determine if anxiety, somatization and depression influence the association. They found symptomatic GERD was a risk factor for TMD, and people with a longer history of GERD had a higher risk of TMD than those with a shorter history.

"The interactions between chronic musculoskeletal diseases, gastrointestinal diseases, mental disorders and sleep problems are complicated," writes Dr. Jihua Chen, The Dental College of Georgia, Augusta, Georgia, and The Fourth Military Medical University, Xi'an, China, with coauthors. "There is evidence to support the bidirectional nature of the associations among these comorbidities, and patients may be stuck in a cycle in which undermined sleep, somatization and anxiety exacerbate the pain, with the pain also leading to sleep problems and mental disorders."

The authors suggest physicians need to be aware of the association and consider multidisciplinary management programs to help patients with TMD and chronic pain.

"Physicians and patients may overlook the association between chronic musculoskeletal disease and gastrointestinal symptoms," write the authors. "Patients with both chronic TMD and reflux symptoms may be underdiagnosed, resulting in deferred effective treatment and a prolonged disease course."

"Associations among gastroesophageal reflux disease, mental disorders, sleep and chronic temporomandibular disorder: a case-control study" is published August 19, 2019.

DALLAS, August 19, 2019 -- Prescription omega-3 fatty acid medication reduces triglyceride levels by 20-30% among the majority of people who require treatment for high triglyceride levels, according to a science advisory from the American Heart Association.

"From our review of the evidence from 17 randomized, controlled clinical trials on high triglyceride levels, we concluded that treatment with 4 grams daily of any of the available prescription choices is effective and can be used safely in conjunction with statin medicines that lower cholesterol," said Ann Skulas-Ray, Ph.D., an author of the new science advisory published in the American Heart Association journal Circulation.

There are two prescription omega-3 fatty acid medications available. One combines two types of fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). The other medication provides EPA only. Since there have been no head-to-head comparisons of the two different formulations at prescription dosing, the advisory does not recommend one over the other.

Triglycerides are fats that circulate in the blood. Some studies have shown that elevated levels of triglycerides (above 200 mg/dL) can lead to atherosclerosis (narrowing of the arteries) which increases the risk of heart attack and stroke. In addition to cardiovascular risk, very high levels of triglycerides (above 500 mg/dL) can also cause pancreatitis, an inflammation of the pancreas.

Skulas-Ray points out that people with high triglyceride levels should not try to treat the condition themselves with non-prescription, omega-3 fatty acid fish oil supplements.

"Dietary supplements containing omega-3 fatty acids are not regulated by the FDA. They should not be used in place of prescription medication for the long-term management of high triglycerides," said Skulas-Ray, who is an assistant professor in the Department of Nutritional Sciences at the University of Arizona in Tucson. In a 2017 science advisory, the American Heart Association noted that there is a lack of scientific research to support clinical use of omega-3 fatty acid supplements to prevent heart disease in the general population.

The effective dose for prescription omega-3 fatty acids is four grams per day taken with food. Currently, the FDA has approved prescription omega-3 fatty acid medications only for treating very high triglyceride levels above 500 mg/dL.

Healthy lifestyle choices, such as getting regular physical activity, losing weight, avoiding sugar and refined carbohydrates, limiting alcohol as well as choosing healthier fats from plants in place of saturated fats can help reduce triglycerides. It is also important to treat or eliminate conditions such as poorly controlled type 2 diabetes, hypothyroidism and obesity that may contribute to high triglyceride levels before turning to medication.

Fish is a good source of omega-3 fatty acids, and the American Heart Association recommends eating fatty fish - such as salmon, mackerel, herring and albacore tuna - at least two times per week.

In analyzing the current scientific data, the advisory panel found:

For most people with high triglycerides (200 to 499 mg/dL), prescription doses of omega-3 fatty acids using drugs with either EPA+DHA or EPA alone can reduce triglyceride by 20 to 30%.

Contrary to common perception, the formula that contains both EPA and DHA does not increase the "bad" form of cholesterol (LDL-C) among most people with high triglyceride levels (200-499 mg/dL). However, when the drug is given to people with very high triglyceride levels at 500 mg/dL or greater, LDL-C may increase.

The panel's review found that the prescription omega-3 drugs are effective in reducing triglyceride levels regardless of whether people are on statin therapy.

In a recent large, randomized placebo-controlled study called REDUCE-IT, researchers found that the EPA-only medication combined with statin medication resulted in a 25% reduction in major cardiovascular events (heart attack, stroke and cardiovascular death) among people with high triglycerides.

Elevated triglycerides are relatively common among people in the United States, and the prevalence is increasing due to growing rates of obesity and diabetes. Both of those conditions raise triglyceride levels. About 25% of adults in the U.S. have a triglyceride level above 150 mg/dL, which is considered borderline high.

PITTSBURGH, Aug. 19, 2019 - There is a dearth of scientifically investigated, evidence-based interventions to address substance use, mental health conditions and violence victimization in sexual and gender minority youth, according to a research review led by the University of Pittsburgh Graduate School of Public Health and published today in the journal Pediatrics.

After poring over thousands of research publications spanning nearly two decades, the scientists identified only nine studies that evaluated such interventions, and most of these used suboptimal study designs, thereby limiting the validity of the findings. None of the programs would be sufficient to mitigate the substantial inequities faced by lesbian, gay, bisexual, transgender and queer (LGBTQ) youth, the scientists concluded.

"While this knowledge gap is distressing, I think we can look at it as an opportunity," said lead author Robert W.S. Coulter, Ph.D., M.P.H., assistant professor in Pitt Public Health's Department of Behavioral and Community Health Sciences. "Promising programs are being created by community-based organizations that are ripe for rigorous evaluation by scientists to determine if they are successfully improving health among LGBTQ youth and, if so, whether they can be replicated in other communities."

Compared with their heterosexual peers, sexual minority youth have up to 623% higher odds of substance use in their lifetimes; up to 317% higher odds of mental health conditions, such as suicidality and depression; and up to 280% higher odds of violence victimization, such as being bullied at school, or sexually or physically abused. Due to these health inequities, the federal government has designated LGBTQ youth as a priority population for research focused on preventing, reducing and treating these health issues.

Despite this designation, the few studies Coulter and his team found primarily focused on individual therapy and only a couple on population-level interventions designed to reduce inequities in the communities where LGBTQ youth live, attend school and play.

"One-on-one therapy can be an effective intervention, but it is inherently focused on treating the victim, rather than preventing the larger societal problems, such as discrimination, that can lead to substance abuse, bullying and mental health issues," said Coulter. "Our study identified a need for evaluation of larger interventions targeting an entire population -- such as at schools -- to bring about cultural changes promoting acceptance and celebration of differences. Such programs may prevent problems from ever arising and make youth more resilient from a health perspective in the future."

Coulter noted that just because his team's literature review didn't find studies evaluating such programs, that doesn't mean they don't exist. It's more likely that limited funding prompted organizers to put their resources into programming, with nothing left for scientific evaluation into whether the programs made a positive impact.

However, Coulter said, rigorous scientific evaluation of health interventions to validate whether or not they work is crucial to securing future funding that can allow successful programs to continue and expand, as well as to improve or halt unsuccessful interventions.

He also said that it is possible they didn't find many interventions because his team was specifically focused on children younger than 18, a population that can be more difficult to include in research studies because they haven't reached the age of consent.

"But adolescent brains are at a crucial developmental stage," Coulter said. "Interventions that successfully prevent undue stress, increase support and build resilience, can pay dividends down the line."

Coulter recently received a grant from the National Institute on Alcohol Abuse and Alcoholism to create a school-based intervention to train staff in ways to better support LGBTQ youth. He intends to incorporate a community-based stakeholder advisory group and apply the scientific method to evaluating the intervention.