It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, June 16, 2021
Compounds derived from hops show promise as treatment for common liver disease
CORVALLIS, Ore. - Research by Oregon State University suggests a pair of compounds originating from hops can help thwart a dangerous buildup of fat in the liver known as hepatic steatosis.
The findings, published today in eLife, are important because the condition affects roughly one-fourth of people in the United States and Europe. While heavy drinking is often associated with liver problems, people with little or no history of alcohol use comprise that 25%, which is why their illness is known as non-alcoholic fatty liver disease, or NAFLD.
Resistance to insulin, the hormone that helps control blood sugar levels, is a risk factor for NAFLD, as are obesity, a high-fat diet and elevated levels of fat in the blood. The liver helps the body process nutrients and also acts as a filter for the circulatory system, and too much fat in the liver can lead to inflammation and liver failure.
In a mouse-model study, Oregon State researchers led by Adrian Gombart showed that the compounds xanthohumol and tetrahydroxanthohumol, abbreviated to XN and TXN, can mitigate diet-induced accumulation of fat in the liver.
XN is a prenylated flavonoid produced by hops, the plant that gives beer its flavor and color, and TXN is a hydrogenated derivative of XN.
In the study, 60 mice were randomly assigned to one of five groups - low-fat diet, high-fat diet, high-fat diet supplemented by XN, high-fat diet supplemented by more XN, and high-fat diet supplemented by TXN.
The scientists found that TXN helped put the brakes on the weight gain associated with a high-fat diet and also helped stabilize blood sugar levels, both factors in thwarting the buildup of fat in the liver.
"We demonstrated that TXN was very effective in suppressing the development and progression of hepatic steatosis caused by diet," said Gombart, professor of biochemistry and biophysics in the OSU College of Science and a principal investigator at the Linus Pauling Institute. "TXN appeared to be more effective than XN perhaps because significantly higher levels of TXN are able to accumulate in the liver, but XN can slow progression of the condition as well, at the higher dose."
The mechanism behind the compounds' effectiveness involves PPARγ, a nuclear receptor protein - one that regulates gene expression. PPARγ controls glucose metabolism and the storage of fatty acids, and the genes it activates stimulate the creation of fat cells from stem cells.
XN and TXN act as "antagonists" for PPARγ - they bind to the protein without sending it into action, unlike a PPARγ agonist, which would activate it as well as bind to it. The upshot of antagonism in this case is less fat collecting in the liver.
"Activated PPAR? in liver stimulates storage of lipids and our data suggest that XN and TXN block activation and greatly reduce expression of the genes the promote lipid storage in the liver," Gombart elaborated. "These findings are consistent with studies that show weaker PPARγ agonists are more effective at treating hepatic steatosis than strong agonists. In other words, lower PPARγ activation in the liver may be beneficial."
TXN was better at accumulating in the liver than XN, which may explain why it was more effective in reducing lipids, but the difference in tissue accumulation is not fully understood.
"It may be because XN is metabolized by the host and its gut microbiota more than TXN is, but additional studies are needed to figure that out," Gombart said. "Also, while XN and TXN are effective preventative approaches in rodents, future studies need to determine if the compounds can treat existing obesity in humans. But our findings suggest antagonism of PPARγ in the liver is a logical approach to prevent and treat diet-induced liver steatosis and related metabolic disorders, and they support further development of XN and TXN as low-cost therapeutic compounds."
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Also collaborating on this research were Yang Zhang, Matthew Robinson, Donald Jump and Carmen Wong of OSU's College of Public Health and Human Sciences; Gerd Bobe of the College of Agricultural Sciences; Cristobal Miranda and Fred Stevens of the College of Pharmacy; Malcolm Lowry, Thomas Sharpton, Claudia Maier and Victor Hsu of the College of Science; and Christiane V. Lo?hr of the Carlson College of Veterinary Medicine.
Funding the study were the National Institutes of Health; the Linus Pauling Institute; the OSU College of Pharmacy; Hopsteiner, Inc; and the OSU Foundation Buhler-Wang Research Fund.
Enormous flock of declining shorebird discovered in South Carolina
Small island hosts world's largest night roost for whimbrel
IMAGE: WHIMBREL ARE LARGE, STRIKING SHOREBIRDS KNOWN FOR THEIR DOWNCURVED BILLS, WHICH ARE IDEALLY ADAPTED TO PLUCKING FIDDLER CRABS FROM MUDDY BURROWS. view more
CREDIT: MATT AEBERHARD/CORNELL LAB OF ORNITHOLOGY
CHARLESTON, S.C. (June 15, 2021) - It's not every day that someone discovers a new-to-science bird migration spectacle. It's even more unexpected that such an encounter - in this case, tens of thousands of shorebirds gathering during their annual journey north - would be just a stone's throw from a metropolitan area. But two years ago, that's exactly what happened in coastal South Carolina.
In May 2019, South Carolina Department of Natural Resources (SCDNR) biologist Felicia Sanders and a team of researchers confirmed that approximately 20,000 whimbrel were roosting at night on a small island during their spring migration. The team documented similar numbers again in 2020. This single flock includes nearly half of the declining shorebird's estimated eastern population: a staggering spectacle hiding in plain sight. The findings were recently published in the peer-reviewed scientific journal Wader Study.
Sanders has devoted her career to protecting South Carolina's coastal birds. After decades exploring the coast, few are more familiar with the way shorebirds and seabirds use the state's salt marshes, tidal creeks and barrier islands. But when Sanders pursued a hunch about the large numbers of whimbrel she saw congregating at Deveaux Bank - a small island just 20 miles south of Charleston - she could barely believe what she'd found.
"A lot of people were skeptical, but after tallying results from coordinated surveys by fellow ornithologists and video documentation, we are certain of the magnitude of the flock," said Sanders. "Finding so many whimbrel here gives me hope that we can turn the tide for this and other declining shorebird species."
Whimbrel are large, striking shorebirds known for their downcurved bills, which are ideally adapted to plucking fiddler crabs from muddy burrows. Like many shorebirds, they migrate incredible distances across the western hemisphere each year, facing threats including habitat loss and overhunting along the way. In the last 25 years, whimbrel declined by two-thirds across the Atlantic Flyway, the eastern portion of their population. The discovery of a roost of this size - the largest known for the species - is of critical importance to successfully protecting this rare shorebird.
After spending the winter on the coasts of South America, whimbrel fly thousands of miles north to nest and raise young across subarctic regions of Canada and Alaska. They typically make just one stop along the way. For many of these birds, that stop is in South Carolina, where they rest and feed on rich coastal nutrients that will fuel their breeding season.
At high tides and at night, when feeding habitat and other safe resting sites are inundated, whimbrel flock together for safety. They seek large, isolated offshore refuges like Deveaux Bank, where disturbances from people and predators are minimal. But relatively few such places remain along the Atlantic coast.
"Having such a globally important phenomenon occur right here in our own backyards, that's really something to be proud of," said Sanders. "And I think it's really important to understand that biologists aren't the only ones that care about these birds. Local communities take ownership of places near their homes. It really does take a village to protect places as important as Deveaux."
Riley Bradham, mayor and lifelong resident of nearby Rockville, agrees. "It's a special place," said Bradham, who has been visiting Deveaux for his entire life and working for years with SCDNR to protect birds on the sensitive island. "We all love it, but it's one of the last special places."
In early 2019, Sanders' discovery inspired a collaboration between the South Carolina Department of Natural Resources, the University of South Carolina, the Cornell Lab of Ornithology and the conservation nonprofit Manomet to census and film this nocturnal roost during peak migration in April and May. For optimal visibility, the shorebird biologists, along with videographers specializing in filming sensitive wildlife, converged on Deveaux on full moon nights as flocks of whimbrel arrived during and after twilight.
"We worked to visually document what Felicia and the team have uncovered here, because this truly unique spectacle underscores the value of the wild spaces still left intact on our southeastern coasts," said Andy Johnson, who led a team from the Cornell Lab's Center for Conservation Media to film the whimbrel roost.
A shorebird roost of this magnitude offers a glimpse of the abundance that was once widespread across the Atlantic coast and now stands as a testament to South Carolina's commitment to coastal habitat conservation.
"There's only one place in the world, one place on Earth where 20,000 whimbrel land on an ephemeral island of really insignificant size," says Chris Crolley, naturalist, guide, and CEO of Charleston-based Coastal Expeditions. "That's Deveaux Bank. Right off the coast of South Carolina. It's just phenomenal, isn't it? It's nothing less than that."
CAPTION
At high tides and at night, when feeding habitat and other safe resting sites are inundated, whimbrel flock together for safety. They seek large, isolated offshore refuges like Deveaux Bank, where disturbances from people and predators are minimal.
CREDIT
Matt Aeberhard/Cornell Lab of Ornithology
Deveaux Bank Seabird Sanctuary is closed year-round above the high-water line, apart from areas designated by signs for limited recreational use (beaches on the ends of the island, facing inland). From March 15 through October 15, some of the island's beaches are closed for seasonal nesting of coastal birds and are demarcated by fencing. Dogs and camping are prohibited year-round.
YOU'RE INVITED: On Tuesday, June 22 at 6 p.m., join the team who made the discovery at Deveaux for a free virtual screening and panel discussion. Click here to learn more and register: http://bit.ly/WhimbrelDiscovery
Sanders, F.J., M.C. Handmaker, A.S. Johnson & N.R. Senner. Nocturnal roost on South Carolina coast supports nearly half of Atlantic coast population of Hudsonian Whimbrel Numenius hudsonicus during northward migration. Wader Study 128(2). DOI: 10.18194/ws.00228
Glyphosate pesticides persist for years in wild plants and cause flower infertility
Researchers show for first time that commonly used herbicides can persist within wild forest plants for years, reducing fertility long-term and potentially also impacting pollinators
An herbicide widely used in agriculture, forestry and other applications can cause deleterious effects on the reproductive health of a common perennial plant found in forests in British Columbia, Canada. Researchers reported in the journal Frontiers in Plant Science that glyphosate-based herbicides (GBH) deformed various reproductive parts on prickly rose (Rosa acicularis) a year after the chemicals were first applied in both field sites and experimental plots.
The study is one of the first to look at the effects of GBH on the reproductive morphology of a prevalent perennial plant in a commercial forestry operation. The herbicide is commonly used to control plants that could compete with conifers that are grown to be harvested in areas known as 'cutblocks'. Glyphosate has been used since the 1970s but has come under increased scrutiny in recent years over concerns about carcinogenic effects on human health.
Investigators from the University of Northern British Columbia (UNBC) collected and analyzed samples of prickly rose reproductive parts from three cutblocks, as well as from greenhouse-grown wild plants, and compared them against untreated plants from similar sources.
The results were striking: Pollen viability of plants treated with glyphosate dropped by an average of 66% compared to the controls a year after the initial application. More than 30% of anthers, the part of the stamen that contains the pollen, failed to split open (a process known as dehiscence), condemning these flowers to functional infertility. In addition, researchers found traces of GBH on plant flowers two full years after the herbicide was first sprayed.
"The changes to plants have been documented in the past, in agricultural plants, so it is not surprising to find them in forests," said Dr. Lisa J. Wood, an assistant professor in the Department of Ecosystem Science and Management at UNBC. "What is important is the timeline. To continue to find these effects one to two years after herbicide applications, in new parts of growing plants, is noteworthy."
For centuries, indigenous people used prickly wild rose as both food and medicine, particularly the reproductive parts. R. acicularis is also an important plant ecologically, in part, because it provides food for pollinators. Honeybees, for example, are attracted to particular colors displayed by the flowers.
Wood and lead author Alexandra Golt, a graduate student at UNBC, observed color changes in flower petals and anthers of treated plants. Such abnormalities in coloration could affect the interaction between flowers and pollinators.
Wood said a follow-up study will investigate whether coloration changes in the GHB-treated flowers make them less or more attractive to pollinators. The researchers will also test pollinator insects and hummingbird feces to check if glyphosate residue is present.
"This will tell us if pollinators are taking up residues from the plants they feed on," she explained. "We will also research other plants to see if the changes we observed in the wild rose are also found in other flowers."
Wood said that while past research shows glyphosate is not acutely toxic to most organisms at the levels applied commercially in Canada, scientists don't know a lot about the chronic implications of glyphosate use or how it changes the dynamics of the natural environment - such as the interactions between species or the available food quality.
"The more we learn the better, and research can always be used to better inform management," Wood noted. "Herbicide practices may change, if the research shows that this is in the public's best interest."
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Small streams in agricultural ecosystems are heavily polluted with pesticides
The environmental risks of pesticides need to be revised
IMAGE: FOR TWO YEARS, RESEARCHERS STUDIED PESTICIDE CONTAMINATION
IN SMALL STREAMS IN AGRICULTURAL LANDSCAPES. view more
CREDIT: ANDRÉ KUENZELMANN / UFZ
Pesticides safeguard agricultural yields by controlling harmful insects, fungi, and weeds. However, they also enter neighbouring streams and damage the aquatic communities, which are crucial for maintaining biodiversity, are part of the food web and support the self-purification of water. In a nationwide monitoring programme, a consortium of scientists led by the Helmholtz Centre for Environmental Research (UFZ) has shown that the governmental thresholds for pesticides are generally too high and that even these excessively high levels are still exceeded in over 80% of water bodies. As they published in the scientific journal Water Research the loss of biodiversity can only be halted if the environmental risk assessment of pesticides is radically revised.
For two years, the researchers studied pesticide contamination at more than 100 monitoring sites on streams flowing through predominantly agricultural lowland regions in 12 federal states in Germany. They found significant exceedances of the RAC value - the concentration of an active ingredient specified in the official approval procedure for a pesticide, which should not be exceeded in the water body in order to prevent negative effects on aquatic organisms. In most of the small streams investigated, the RAC values were exceeded (81%). In 18% of the streams, such exceedances were detected for more than 10 pesticides. "We have detected a significantly higher pesticide load in small water bodies than we originally expected", says Prof. Matthias Liess, ecotoxicologist at the UFZ and coordinator of the small water monitoring project. For example, in three water bodies, the insecticide thiacloprid exceeded the RAC value by more than 100-fold. In 27 streams the insecticides clothianidin, methiocarb, and fipronil as well as herbicides such as terbuthylazine, nicosulfuron, and lenacil exceeded the RAC value 10- to 100-fold.
Because of the extensive data set, the researchers were able to reveal that pesticides affect aquatic invertebrate communities at much lower concentrations than previously assumed by the pesticide risk assessment. The concentrations depend on which species are to be conserved. For example, sensitive insect species such as caddisflies and dragonflies require much lower (1.000-fold) threshold values than snails and worms. "For sensitive insect species, the pesticide concentration in the small lowland streams is the most relevant factor that determines their survival. In contrast, other environmental problems such as watercourse expansion, oxygen deficiency, and excessive nutrient content are less important. For the first time this study allows a ranking of environmental problems", says Liess.
For the current approval of pesticides, the high sensitivity of species in the ecosystem context is grossly underestimated. Until now, the ecological risk of pesticides in the field has been predicted based on laboratory studies, artificial ecosystems, and simulation models. However, according to Liess, the results from the laboratory do not reflect reality. "In addition to pesticides, many other stressors act on organisms in the ecosystem. These make them much more sensitive to pesticides. Natural stressors such as predation pressure or competition between species are not sufficiently taken into account in the risk assessment. But these obvious problems often go unnoticed because the degree of pesticide contamination and the effect of this have not been validated in the field - neither in Germany nor in other countries", he says.
In the course of the project, the scientists also found that the type of sampling has a drastic influence on the concentrations of pesticides measured. In addition to the scoop sample specified as standard by the EU Water Framework Directive, they also took an "event sample". Here, an automatically controlled sampler takes water samples from the water body after a rain event. "The event sample provides much more realistic results because the pesticides enter the water bodies as a result of the increased surface run-off from the field, especially during rain", says Liess. Compared to the scoop samples, the event-related samples show a 10-fold higher pesticide load. "In order to realistically depict the water pollution, samples must therefore be taken after rainfall events. That's why we need an official regular environmental monitoring to be able to assess the amount and the effects of pesticides," says Matthias Liess. He and his colleagues also demand that new scientific findings be incorporated into the approval process for new pesticides more quickly. "We are still using pesticides that were approved many years ago based on an outdated risk assessment. This must therefore change as soon as possible. Only in this way can we preserve the biodiversity in our waters and with it the services that these biotic communities provide for our ecosystems."
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The pilot study "Small Water Body Monitoring" (KgM) commissioned by the Federal Environment Agency was carried out under the leadership of the UFZ Department of System-Ecotoxicology and financed by the UFZ and the Federal Environment Agency. Eleven UFZ departments, the University of Koblenz-Landau, the University of Duisburg-Essen, the University of Kiel, the Federal Environment Agency, and the environmental authorities of the 12 participating federal states participated.
IMAGE: JUST TWO WEEKS OF CITALOPRAM EXPOSURE CAUSED CHANGES IN CRAYFISH BEHAVIOR. view more
CREDIT: STEFAN, INATURALIST
Pharmaceutical pollution is found in streams and rivers globally, but little is known about its effects on animals and ecosystems. A new study, published in the journal Ecosphere, investigated the effects of antidepressant pollution on crayfish. Just two weeks of citalopram exposure caused changes in crayfish behavior, with the potential to disrupt stream ecosystem processes like nutrient cycling, oxygen levels, and algal growth.
Coauthor Emma Rosi, a freshwater ecologist at Cary Institute of Ecosystem Studies, says, "Animals living in streams and rivers are exposed to a chronic mix of pharmaceutical pollution as a result of wastewater contamination. Our study explored how antidepressant levels commonly found in streams impact crayfish, and how these changes reverberate through stream ecosystems."
Crayfish are a keystone species in streams, where they eat invertebrates, break down leaf litter, and cycle nutrients. They are stress-tolerant and can become abundant in urban waterways. These freshwaters are prone to receiving pharmaceutical pollution from sewer overflows, leaky septic tanks, and treated wastewater effluent that contains pharmaceuticals.
Lead author Alexander Reisinger, an Assistant Professor at University of Florida, Gainesville, says, "Previous research via direct injection found that antidepressants alter serotonin and aggression in crustaceans. Our study found that exposure to low doses of citalopram - at levels currently found in urban streams as a result of pollution - is enough to alter crayfish behaviors like foraging, aggression, and shelter use."
Cary Institute's artificial stream facility was used to test effects of citalopram on crayfish and stream ecosystems. Twenty stream habitats were created with low-nutrient groundwater and quartz rocks and red maple leaf packs that had been colonized with microbes, invertebrates, and algae. Streams were randomly selected to receive one of four treatments: no citalopram + no crayfish, citalopram + no crayfish, crayfish + no citalopram, and citalopram + crayfish. Each treatment was applied to five streams. Three male crayfish were added to each of the 'crayfish' streams.
For two weeks, the team dosed the 10 streams receiving citalopram every other day to mimic low, persistent pharmaceutical pollution found in urban streams. Over the course of the experiment, they monitored indicators that would reveal changes in stream ecosystem functioning, such as dissolved oxygen, temperature, light penetration, and algae. At the end of the two weeks, the behavior of exposed and non-exposed crayfish was tested.
To do this, the team tapped into crayfish's keen sense of smell. They used a tank containing a shelter at one end and a divider down the middle. One side of the tank contained water that had passed by sardine gelatin; the other contained water that had passed by another male crayfish. One at a time, they placed the crayfish in the shelter, then recorded the amount of time it took for each to peek out of the shelter and emerge completely. They also recorded the amount of time spent in the sardine and crayfish signal sides of the tank.
Crayfish exposed to citalopram emerged from the shelter sooner, indicating increased 'boldness'. Exposed crayfish were also more interested in food, lingering in the food-scented area over 3x longer than the crayfish-scented area. Crayfish that were not exposed to citalopram took longer to emerge and divided their time equally between the food and crayfish areas, showing no preference.
Reisinger explains, "Citalopram-exposed crayfish are more attracted to food, and less interested in other crayfish. Less time spent hiding and more time foraging could make crayfish more vulnerable to predators, meaning more get eaten. We would expect increased crayfish foraging to lead to higher rates of leaf litter decomposition and biofilm turnover, altering in-steam nutrient flows. Either of these changes could have cascading effects."
In people, 'metabolism' refers to a collection of chemical processes that regulate bodily functions essential to health like breathing, digestion, and temperature regulation. Stream 'metabolism' includes a variety of indicators like oxygen levels, light penetration, and nutrient cycling, which together shape stream health.
The team used their two-week record of stream indicators to assess changes in the metabolism of each stream. They found that crayfish presence versus absence significantly affects stream metabolism. Effects of citalopram alone were not significant, but results suggest that changes in stream functioning would likely occur over time due to citalopram's effects on crayfish behavior.
Reisinger explains, "With just two weeks of citalopram exposure, we saw marked changes in crayfish behavior. Over months to years, we would expect these changes to magnify. Fewer crayfish could reduce populations of the fish that eat them like trout, bass, and catfish. Changes in algal growth or turnover would alter oxygen levels and nutrient dynamics - key aspects of stream functioning that could cause harmful imbalances in the system."
Rosi concludes, "Toxicity assessments of pharmaceuticals often focus on lethal effects, but it is clear that these drugs can affect non-target organisms without killing them and behavioral changes can have ecological consequences. More work is needed to understand how pharmaceutical pollution impacts stream life at chronic, sublethal levels, and what these changes mean for freshwater quality, ecosystem health, and foodwebs - in streams and beyond."
CAPTION
Three months before the experiment, the team placed packets of dried maple leaves and quartz rocks in a local creek and left them to gather communities of algae, bacteria, fungi, and invertebrates. The colonized leaf packs and rocks were then placed in Cary Institute's artificial streams to mimic a natural stream ecosystem.
CREDIT
AJ Reisinger
Investigators
Alexander Reisinger - University of Florida, Soil and Water Sciences Department Lindsey Reisinger - University of Florida, Fisheries and Aquatic Sciences Program Erinn Richmond - Monash University, Water Studies Center, School of Chemistry Emma Rosi - Cary Institute of Ecosystem Studies
Cary Institute of Ecosystem Studies is an independent nonprofit center for environmental research. Since 1983, our scientists have been investigating the complex interactions that govern the natural world and the impacts of climate change on these systems. Our findings lead to more effective management and policy actions and increased environmental literacy. Staff are global experts in the ecology of: cities, disease, forests, and freshwater.
CAPTION
The spinycheek crayfish used in the study were collected from a local stream.
CREDIT
AJ Reisinger
Not acting like themselves: Antidepressants in environment alter crayfish behavior
Crayfish exposed to low levels of antidepressant medication behaved in ways that could make them more vulnerable to predators
UNIVERSITY OF FLORIDA
WITH MUSIC
VIDEO: CRAYFISH IN LINDSEY REISINGER'S LAB AT THE UNIVERSITY OF FLORIDA.view more
CREDIT: BRIANNE LEHAN/UNIVERSITY OF FLORIDA
Antidepressants can help humans emerge from the darkness of depression. Expose crayfish to antidepressants, and they too become more outgoing -- but that might not be such a positive thing for these freshwater crustaceans, according to a new study led by scientists with the University of Florida.
"Low levels of antidepressants are found in many water bodies," said A.J. Reisinger, lead author of the study and an assistant professor in the UF/IFAS soil and water sciences department. "Because they live in the water, animals like crayfish are regularly exposed to trace amounts of these drugs. We wanted to know how that might be affecting them," he said.
Antidepressants can get into the environment through improper disposal of medications, Reisinger said. In addition, people taking antidepressants excrete trace amounts when they use the bathroom, and those traces can get into the environment through reclaimed water or leaky septic systems.
The researchers found that crayfish exposed to low levels of antidepressant medication behaved more "boldly," emerging from hiding more quickly and spending more time searching for food.
"Crayfish exposed to the antidepressant came out into the open, emerging from their shelter, more quickly than crayfish not exposed to the antidepressant. This change in behavior could put them at greater risk of being eaten by a predator," said Lindsey Reisinger, a co-author of the study and an assistant professor in the UF/IFAS fisheries and aquatic sciences program.
"Crayfish eat algae, dead plants and really anything else at the bottom of streams and ponds. They play an important role in these aquatic environments. If they are getting eaten more often, that can have a ripple effect in those ecosystems," Lindsey Reisinger added.
In their study, conducted while A.J. Reisinger was a postdoctoral researcher at the Cary Institute of Ecosystem Studies, the scientists wanted to understand how crayfish respond to low levels of antidepressants in aquatic environments.
"Our study is the first to look at how crayfish respond when exposed to antidepressants at levels typically found in the streams and ponds where they live," A.J. Reisinger said.
The researchers achieved this by recreating crayfish's natural environment in the lab, where they could control the amount of antidepressant in the water and easily observe crayfish behavior.
Crayfish were placed in artificial streams that simulated their natural environment. Some crayfish were exposed to environmentally realistic levels of antidepressant in the water for a few weeks, while a control group was not exposed. The researchers used a common type of antidepressant called a selective serotonin reuptake inhibitor, or SSRI.
To test how antidepressant exposure changed crayfish behavior, researchers used something called a Y-maze. This maze has a short entrance that branches into two lanes, like the letter Y.
At the start of the experiment, the researchers placed each crayfish in a container that acted as a shelter, and that shelter was placed at the entrance to the maze.
When researchers opened the shelter, they timed how long it took for the crayfish to emerge. If the crayfish emerged, they had the choice of the two lanes in the Y-maze. One lane emitted chemical cues for food, while the other emitted cues that signaled the presence of another crayfish. The researchers recorded which direction the crayfish chose and how long they spent out of the shelter.
Compared to the control group, crayfish exposed to antidepressants emerged from their shelters earlier and spent more time in pursuit of food. They tended to avoid the crayfish side of the maze, a sign that the levels of antidepressants used in study didn't increase their aggression.
"The study also found that crayfish altered levels of algae and organic matter within the artificial streams, with potential effects on energy and nutrient cycling in those ecosystems," A.J. Reisinger said. "It is likely that the altered crayfish behavior would lead to further impacts on stream ecosystem functions over a longer time period as crayfish continue to behave differently due to the SSRIs. This is something we'd like to explore in future studies."
The study, co-authored with Erinn Richmond of Monash University and Emma Rosi of the Cary Institute of Ecosystem Studies, is published in the journal Ecosphere.
Wondering how you can reduce the levels of antidepressants and other pharmaceuticals in water bodies? There are steps people can take, A.J. Reisinger said.
"The answer is not for people to stop using medications prescribed by their doctor. One big way consumers can prevent pharmaceuticals from entering our water bodies is to dispose of medications properly," he said.
WITHOUT MUSIC
A.J. Reisinger has authored an Extension publication and infographic on how to dispose of unwanted medications properly and keep them out of water bodies.
Baltic herring larvae appear earlier and grow faster due to climate change
Data collected for over two decades shows that rising Baltic Sea water temperature is one of the main factors in the increasingly earlier appearance and faster growth of Baltic herring larvae.
Baltic herring (Clupea harengus membras) is commercially the most important fish species in Finland, and an important part of the Baltic marine ecosystem. Conditions during herring spawning may have cascading effects on the whole Baltic ecosystem.
According to a recent research, both developmental stages in Baltic herring larvae, small and large, have shifted their timing to earlier dates.
"This suggests that herring spawn earlier and larvae grow faster, by about 7.7 days per decade. Water temperature and the amount of chlorophyll a in the water, the latter serving as an estimate for the larval food resources, were strong drivers of this change," says postdoctoral researcher Benjamin Weigel from the University of Helsinki.
"The results of the study describe the effects of climate change on the Baltic Sea ecosystem and one of its key species," says research programme leader Meri Kallasvuo from Natural Resources Institute Finland.
Temporal changes in the biological life cycle of Baltic herring can become critical for the survival of species when there is a mismatch in timing between prey and consumer, especially during early life stages.
Researchers from the University of Helsinki and Natural Resources Institute Luke used data collected over 22 years from a herring larvae survey that was conducted in several areas along the whole Baltic coast of Finland.
"Usually there are no exact dates of first larvae hatching available, so we modelled changes in the Baltic herring larvae based on occurrence probabilities and relative abundances of different size classes of fish larvae. We predicted the day of the year when the smallest larvae had a high probability of occurrence, and when largest larvae made up a significant percentage of all larvae. Earlier dates in high occurrence probabilities of the smallest larvae indicate relatively earlier spawning, and earlier dates in proportions of the largest larvae would indicate faster larvae growth," Benjamin Weigel points out.
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Cosmic rays: Coronal mass ejections and cosmic ray observations at Syowa Station in the Antarctic
Solar activities, such as CME(Coronal Mass Ejection), cause geomagnetic storm that is a temporary disturbance of the Earth's magnetosphere. Geomagnetic storms can affect GPS positioning, radio communication, and power transmission system. Solar explosions also emit radiation, which can affect satellite failures, radiation exposure to aircraft crew, and space activity. Therefore, it is important to understand space weather phenomena and their impact on the Earth.
Space weather research by continuous observation of cosmic rays on the ground is mainly conducted using observation data from neutron monitors and multi-directional muon detectors. Since the phenomenon of space weather is on a short-term, days-long scale, it is effective to investigate changes in the flow of cosmic rays for several hours, which requires a total sky monitor of cosmic rays. In the muon detector, the global muon detector network (GMDN) has been observing space weather phenomena since 2006, and in the neutron monitor, the Spaceship Earth project constitutes a similar observation network and the role of the all-sky monitor. Until now, observations by neutron monitors and muon detectors have been performed independently, and progress has been made in space weather research.
In February 2018, Professor Chihiro Kato of Shinshu University took the lead in acquiring simultaneous observations of the neutron monitor and muon detector at Syowa Station in the Antarctic in order to acquire bridging data of observations by the neutron monitor and muon detector. In the polar regions, unlike low latitude regions on the earth, it is possible to observe cosmic rays coming from the same direction with a neutron monitor and a muon detector due to the weaker deflection by the geomagnetism. This is the reason why Syowa Station was selected as the observation point.
Syowa muon detector and neutron monitor observed small fluctuation in CR count like a Forbush decrease on 2018.8. The research group including researchers from Shinshu University and the National Polar Research Institute found curious cosmic-ray density variation on this event by analyzing GMDN data.
On the CME event, a huge amount of coronal material released with a bundle of the solar magnetic field, called Magnetic Flux Rope (MFR), into the interplanetary space. MFR moves through interplanetary space as expanding. CR density is low inside of it because it is originally coronal material. When the Earth enters the MFR, CR counts on the ground decreases. This is called Forbush Decrease.
Normally, when MFR arrives on Earth, CR density observed at the ground level decreases rapidly, and then turns to increase recovering to the original level while the Earth is in the MFR. On this event, however, the CR exceeds the original level before the Earth exits the MFR.
This event attracts interest from researchers because 1) The solar activity is currently near the minimum and the scale of the event itself is small, 2) It causes a disproportionately large geomagnetic storm, and 3) There is high-speed solar wind catching up the MFR expected to interact with it.
By analysis of the GMDN and solar plasma data, it is concluded that the high-speed solar wind causes the unusual enhancement of the CR density by compressing the rear part of the MFR locally.
Cosmic ray observation data is closely related not only to space weather research but also to atmospheric phenomena such as sudden stratospheric temperature rise and is expected to be used in a wide range of fields in the future. The cosmic ray observation data at Syowa Station, including the phenomenon in August 2018, which was the subject of this research, is published on the website and updated daily: http://polaris.nipr.ac.jp/~cosmicrays/
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Acknowledgments
The authors are grateful to Center for Antarctic Programs at NIPR (National Institute of Polar Research), JARE59 team, and Shirase crew for installing the system to Syowa Station. This research project is supported by NIPR, ICRR (Institute of Cosmic Ray Research, Tokyo University), ISEE (Institute for Space-Earth Environmental Research, Nagoya University), University of Delaware, and Shinshu University. Some of the scientific data of this research project has begun to be published at http://polaris.nipr.ac.jp/~cosmicrays/ supported by ROIS-DS-JOINT2018. The Bartol Research Institute neutron monitor program is supported by the United States National Science Foundation under grants PLR-1245939 and PLR-1341562, and by Department of Physics and Astronomy and the Bartol Research Institute, the University of Delaware. The neutron monitor data from Thule are provided by the University of Delaware Department of Physics and Astronomy and the Bartol Research Institute. The neutron monitor data from South Pole and the South Pole Bares are provided by the University of Wisconsin, River Falls. We acknowledge the NMDB database (http://www.nmdb.eu), founded under the European Union's FP7 program (contract no. 213007) for providing data. The editor thanks two anonymous reviewers for their assistance in evaluating this paper.
