Maunakea telescopes confirm first brown dwarf discovered by radio observations

Gemini North and IRTF confirm LOFAR discovery

ASSOCIATION OF UNIVERSITIES FOR RESEARCH IN ASTRONOMY (AURA)

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VIDEO: MAUNAKEA TELESCOPES CONFIRM FIRST BROWN DWARF DISCOVERED BY RADIO OBSERVATIONS view more 

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INTERNATIONAL GEMINI OBSERVATORY/NOIRLAB/NSF/AURA/LOMBERG J, J. CHU/J. POLLARD, E. MASTROIANNI, LOFAR / ASTRON, S. BRUNIER/DIGITIZED SKY SURVEY 2.

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A collaboration between the LOw Frequency ARray (LOFAR) radio telescope in Europe, the Gemini North telescope, and the NASA InfraRed Telescope Facility (IRTF), both on Maunakea in Hawai'i, has led to the first direct discovery of a cold brown dwarf from its radio wavelength emission. Along with paving the way for future brown dwarf discoveries, this result is an important step towards applying radio astronomy to the exciting field of exoplanets.

For the first time, astronomers have used observations from the LOFAR radio telescope, the NASA IRTF, operated by the University of Hawai'i, and the international Gemini Observatory, a Program of NSF's NOIRLab, to discover and characterize a cold brown dwarf. The object, designated BDR J1750+3809, is the first substellar object to be discovered through radio observations -- until now, brown dwarfs have been uncovered in large infrared and optical surveys. Directly discovering these objects with sensitive radio telescopes such as LOFAR is a significant breakthrough because it demonstrates that astronomers can detect objects that are too cold and faint to be found in existing infrared surveys -- maybe even large free-floating exoplanets.

"In this discovery, Gemini was particularly important because it identified the object as a brown dwarf and also gave us an indication of the temperature of the object," explained lead author Harish Vedantham of ASTRON, the Netherlands Institute for Radio Astronomy. "The Gemini observations told us that the object was cold enough for methane to form in its atmosphere -- showing us that the object is a close cousin of Solar System planets like Jupiter."

Brown dwarfs are substellar objects straddling the boundary between the largest planets and the smallest stars [1]. Occasionally dubbed failed stars, brown dwarfs lack the mass to trigger hydrogen fusion in their cores, instead glowing at infrared wavelengths with leftover heat from their formation. While they lack the fusion reactions that keep our Sun shining, brown dwarfs can emit light at radio wavelengths. The underlying process powering this radio emission is familiar, as it occurs in the largest planet in the Solar System. Jupiter's powerful magnetic field accelerates charged particles such as electrons, which in turn produces radiation -- in this case, radio waves [2] and aurorae.

The fact that brown dwarfs are radio emitters allowed the international collaboration of astronomers behind this result to develop a novel observing strategy. Radio emissions have previously been detected from only a handful of cold brown dwarfs -- and they have been known and cataloged by infrared surveys before being observed with radio telescopes. The team decided to flip this strategy, using a sensitive radio telescope to discover cold, faint sources and then perform follow-up infrared observations with a large telescope like the 8-meter Gemini North telescope to categorize them.

"We asked ourselves, 'Why point our radio telescope at cataloged brown dwarfs?'," said Vedantham. "Let's just make a large image of the sky and discover these objects directly in the radio."

Having found a variety of tell-tale radio signatures in their observations, the team had to distinguish potentially interesting sources from background galaxies. To do so, they searched for a special form of light that was circularly polarized [3] -- a feature of light from stars, planets, and brown dwarfs, but not from background galaxies. Having found a circularly polarized radio source, the team then turned to telescopes including Gemini North and the NASA IRTF to provide the measurements required to identify their discovery.

Gemini North is equipped with a variety of infrared instruments, one of which is usually kept ready to observe when an interesting astronomical opportunity arises. In the case of BDR J1750+3809, Gemini's mainstay infrared imager, the Near InfraRed Imager and spectrograph (NIRI) , was not available -- so Gemini astronomers took the unusual step of using the acquisition camera for the Gemini Near-Infrared Spectrograph (GNIRS) instead. Thanks to the careful work and foresight of Gemini staff, this camera provided deep, sharp, and accurate imaging at several infrared wavelengths.

"These observations really highlight the versatility of Gemini, and in particular the little-used 'keyhole' imaging capability of Gemini's GNIRS spectrograph," commented Gemini Observatory and University of Edinburgh astronomer Trent Dupuy -- a co-author of the research paper. The Gemini North observations were obtained via Director's Discretionary Time, which is reserved for programs needing small amounts of observing time with potentially high-impact results.

"This observation showcases both the flexibility and the power of the Gemini Observatories," said Martin Still of the National Science Foundation (NSF). "This was an opportunity where Gemini's design and operations enabled an innovative idea to develop into a significant discovery."

As well as being an exciting result in its own right, the discovery of BDR J1750+3809 could provide a tantalizing glimpse into a future when astronomers can measure the properties of exoplanets' magnetic fields. Cold brown dwarfs are the closest things to exoplanets that astronomers can currently detect with radio telescopes, and this discovery could be used to test theories predicting the magnetic field strength of exoplanets. Magnetic fields are an important factor in determining atmospheric properties and long term evolution of exoplanets.

"Our ultimate goal is to understand magnetism in exoplanets and how it impacts their ability to host life," concluded Vedantham. "Because magnetic phenomena of cold brown dwarfs are so similar to what is seen in Solar System planets, we expect our work to provide vital data to test theoretical models that predict the magnetic fields of exoplanets."

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Notes

[1] The first unambiguous observation of a brown dwarf did not occur until 1995, after more than 30 years of theoretical predictions. The name of these objects was coined by the American astronomer Jill Tarter in reference to their expected color.

[2] The radiation emitted by the acceleration of charged particles in a magnetic field is referred to as cyclotron radiation. The name comes from the cyclotron, an early type of particle accelerator.

[3] Circularly polarized light is also used to create 3D movies.

More information

This research was presented in the paper Direct Radio Discovery of a Cold Brown Dwarf to appear in The Astrophysical Journal Letters.

The team is composed of H. K. Vedantham (ASTRON and University of Groningen), J. R. Callingham (Leiden Observatory and ASTRON), T. W. Shimwell (ASTRON and Leiden Observatory), T. Dupuy (University of Edinburgh and Gemini Observatory/NSF's NOIRLab), William M. J. Best (University of Texas and Visiting Astronomer at the NASA IRTF, Michael C. Liu (University of Hawai'i and Visiting Astronomer at the NASA IRTF), Zhoujian Zhang (University of Hawai'i), K. De (California Institute of Technology), L. Lamy (LESIA, Observatoire de Paris), P. Zarka (LESIA, Observatoire de Paris), H. J. A. Röttgering (Leiden Observatory), and A. Shulevski (Leiden Observatory).

NSF's NOIRLab (National Optical-Infrared Astronomy Research Laboratory), the US center for ground-based optical-infrared astronomy, operates the international Gemini Observatory (a facility of NSF, NRC-Canada, ANID-Chile, MCTIC-Brazil, MINCyT-Argentina, and KASI-Republic of Korea), Kitt Peak National Observatory (KPNO), Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and Vera C. Rubin Observatory. It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. The astronomical community is honored to have the opportunity to conduct astronomical research on Iolkam Du'ag (Kitt Peak) in Arizona, on Maunakea in Hawai?i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the Tohono O'odham Nation, to the Native Hawaiian community, and to the local communities in Chile, respectively.

Links

Research paper
ASTRON Press Release
Institute for Astronomy Press Release
Photos of Gemini North

 

Study: Remote learning adds pressure for teachers who work second shift as mothers

To relieve stress on teacher-mothers, researchers suggest improved parental leave policies, higher teacher pay and more equal distribution of household labor

UNIVERSITY AT BUFFALO

Research News

 

BUFFALO, N.Y - The transition to remote learning coupled with an unequal distribution of second-shift responsibilities has placed teachers who are also mothers under immense stress, according to new University at Buffalo research.

The study explored the experiences and challenges facing teacher-mothers who perform the roles of educator in the classroom and parent at home, while also typically carrying out more household labor than their partners.

These responsibilities are exacerbated by technology that blurs the line between work and home, inadequate parental leave policies and low teacher pay, says study co-author Julie Gorlewski, PhD, chair of the Department of Learning and Instruction in the UB Graduate School of Education.

"Balancing a teaching career and motherhood seems to be becoming more difficult," Gorlewski says. "Both roles carry an expectation of selfless nurturing and can result in physical and emotional exhaustion.

"The implications of this work are particularly relevant today, where the roles of motherhood and teacher are intensified by the shift to online learning as a result of the pandemic. Through a greater understanding of the lived experiences of teacher-mothers, this study can inform policy and practice to better support an integral segment of the education workforce."

The research was published in late October in Educational Studies.

Additional investigators include Mary A. Hermann, PhD, JD, first author and associate professor at Virginia Commonwealth University; Robyn Walsh, PhD, assistant professor at Capital University; Lindsay Kozachuk, PhD, assistant professor at Palm Beach Atlantic University; UB Graduate School of Education doctoral candidate Elizabeth Ciminelli; and Virginia Commonwealth University School of Education doctoral candidates Dana Brookover and Michael Deitz.

Fatigue from rising expectations

The researchers surveyed 12 teacher-mothers across the nation working in elementary, middle and high school settings. During the interviews, several themes emerged around work-life balance, problematic cultural norms and financial difficulties.

The participants shared the benefits of both roles, including how being a mother allowed them to better relate to the parents of their students, and how their work as a teacher provided them with greater awareness of their children's development. However, they also experienced frequent exhaustion from perpetual caregiving, says Gorlewski.

Technology and the transition to remote learning have raised expectations for teachers, who are expected to maintain contact with parents throughout the day and with their students at all hours. These demands build on the additional work teachers perform after school hours on grading and lesson planning.

Due to the COVID-19 pandemic, parents became responsible for homeschooling their children after many schools shuttered. For teachers who have children, this responsibility in the household often fell on them as the parent better trained to provide instruction, says Gorlewski.

Societal norms compound these pressures for mothers, who face elevated expectations at home, says Gorlewski. The research found that teacher-mothers reported performing more second-shift activities (household labor such as cooking, cleaning and child care) than their partners. Even when partners contributed more equally toward household labor, mothers typically engaged in significantly more mental labor planning and managing tasks, she says.

Homemaking standards are also magnified by portrayals of the perfect home on social media, and women are more likely to face judgement if their households do not match these heightened expectations, says Gorlewski.

Opportunity in a time of crisis

The researchers advocate for numerous policy changes to reduce the challenges faced by teacher-mothers, including improved parental leave and teacher pay.

Most participants reported that they had to use sick and personal days to earn pay while they were on maternity leave, leaving them with little to no time off after their child's birth to attend follow-up doctor's appointments. Teachers in their early career are particularly disadvantaged, says Gorlewski, as they have less accrued time off.

Due to the small amount of paid maternity leave and pressure to breastfeed from doctors, nurses and friends, some teacher-mothers reported having to pump at work between classes or while preparing the next day's lesson.

In addition to the second shift, many teacher-mothers also work a second job. One in every six teachers work a second job, and teachers are three times more likely than other professions to have multiple jobs, says Gorlewski.

The researchers encourage schools to enact mentoring programs for new mothers as well, as many participants appreciated being able to ask colleagues for advice on parenting and managing multiple roles.

The pandemic presents the opportunity for the nation to rethink the norms in education and family systems, and for teacher-mothers to renegotiate policies in the classroom and expectations in the household, says Gorlewski.

She calls on partners to take equal responsibility for second-shift labor, and suggests teacher-mothers abandon perfectionistic standards of child care and household maintenance on social media in favor of portrayals that show the messiness of authentic parenthood.

"This unanticipated and challenging global event has the potential to reveal some of the invisible work of mothers and educators," says Gorlewski. "Advocates can use these results to promote better norms and policies to support teachers and all working mothers."

Future research will compare the experiences of teacher-mothers with teacher-fathers and teachers who are not parents.

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Clinicians who prescribe unnecessary antibiotics fuel future antibiotic use

HARVARD MEDICAL SCHOOL

Research News




 

Receiving an initial antibiotic prescription for a viral acute respiratory infection--the type of infection that doesn't respond to antibiotics--increases the likelihood that a patient or their spouse will seek care for future such infections and will receive subsequent antibiotic prescriptions, according to the findings of a study from Harvard Medical School and the Harvard T.H. Chan School of Public Health.

The analysis, published online August 10 in Clinical Infectious Diseases, is believed to be the first to measure how variation in clinicians' antibiotic-prescribing patterns impacts patients' care-seeking behavior and antibiotic use in the long term.

The findings are alarming because they suggest that once such prescriptions are given improperly for a viral infection they could become a gateway to more antibiotic use, the researchers said. Overuse of antibiotics is common. Previous studies have shown that nearly a quarter of antibiotics prescribed in an outpatient setting are given inappropriately for a diagnosis that does not warrant antibiotic treatment.

"The choices physicians make about prescribing antibiotics can have long-term effects on when individual patients choose to obtain care," said lead study author Zhuo Shi, an HMS student in the Harvard-MIT Program in Health Sciences and Technology program. "A physician who prescribes an antibiotic inappropriately needs to understand that it's not just one little prescription of a harmless antibiotic but a potential gateway to a much bigger problem."

The researchers used encounter data from a national insurer to analyze more than 200,000 initial visits for acute respiratory infections (ARIs) at 736 urgent care centers across the United States. At those centers, the researchers found that antibiotic prescribing rates for ARIs varied greatly among clinicians. In the highest quartile of prescribers, 80 percent of clinicians prescribed antibiotics for viral respiratory infections, and in the lowest, 42 percent did. To understand the impact of greater antibiotic prescribing, the researchers exploited the fact that patients do not choose their urgent care clinician. They are essentially randomly assigned to a clinician.

In the year after an initial ARI visit, patients seen by clinicians in the highest-prescribing group received 14.6 percent more antibiotics for ARI--an additional three antibiotic prescriptions filled per 100 patients--compared with patients seen by the lowest-antibiotic-prescribing clinicians. The increase in patient ARI antibiotic prescriptions was largely driven by an increased number of ARI visits, an increase of 5.6 ARI visits per 100 patients, rather than a higher antibiotic prescribing rate during those subsequent ARI visits, the analysis showed.

It's not that they were more likely to get antibiotics on repeat visits, the researchers found, simply that each return visit provided another opportunity to receive antibiotics.

Why? In the case of a viral illness, patients wrongly attribute improvement in symptoms to the antibiotics. Naturally, next time they have similar symptoms they believe they need more antibiotics, the researchers said.

"You'll hear lots of people say, 'Every winter I need antibiotics for bronchitis,'" said study senior author Ateev Mehrotra, an associate professor of health care policy in the Blavatnik Institute at Harvard Medical School and a hospitalist at Beth Israel Deaconess Medical Center. "The antibiotics don't actually help, but patients tend to perceive a benefit. The fancy term for this psychological phenomenon is 'illusionary correlation.'"

"They get antibiotics and they feel better, not because the antibiotics have worked but because the infection has run its course," Mehrotra said. "The next time they become ill with similar symptoms they go back to the doctor to get another prescription."

And the lesson isn't just learned by the patients themselves. Their spouses showed similar increases in visits and use of antibiotics for ARIs.

The inappropriate use of antibiotics is a serious problem, the researchers said, noting that the practice increases spending unnecessarily, exposes patients to the risk of side effects for no medical reason and helps to drive the rise of antibiotic-resistant strains of bacteria.

Using encounter data from a national insurer, the researchers categorized clinicians within each urgent care center based on their ARI antibiotic prescribing rate. The fact that urgent care patients are randomly assigned to a clinician ruled out the possibility that patients might be choosing a physician they knew would likely give them antibiotics for their viral infection, enabling the researchers to examine the impact of physician behavior on future patient behavior. The researchers examined the association between the clinician's antibiotic prescribing rate and the patients' rates of ARI antibiotic receipt as well as their spouses' rate of antibiotic receipt in the subsequent year. Several members of the research team first applied this method to examine pattens of opioid prescribing.

While there is plenty of anecdotal evidence that some physicians say they give antibiotics to patients who request them to improve patient satisfaction, the researchers wanted to see whether and how physician prescribing behavior might be fueling the effect. They set out to answer the question: Could an initial prescription from a high-prescribing physician drive future antibiotic-seeking behavior among patients?

It does, the analysis showed, and the study, the researchers said, underscores the ongoing need to educate clinicians and patients on judicious prescribing practices to reduce inappropriate prescribing, as well as the overall overuse of antibiotics and its associate risks.

###

Support for this study was provided by the Office of the Director, National Institutes of Health (grant 1DP5OD017897).

The following additional co-authors also contributed to the study: Michael Barnett, Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, and Department of Medicine, HMS and Brigham and Women's Hospital; Anupam Jena, Department of Health Care Policy, HMS; Kristin Ray, Department of Pediatrics, University of Pittsburgh School of Medicine; and Kathe Fox, Department of Biomedical Informatics, HMS, and Department of Analytics and Behavior Change, Aetna/CVS Health.

doi.org/10.1093/cid/ciaa1173

 

New study defines life cycle of a destructive plant pathogen 142 years after its discovery

AMERICAN PHYTOPATHOLOGICAL SOCIETY

Research News

 

IMAGE:  "USING CONFOCAL AND ELECTRON MICROSCOPIC IMAGING, WE PROVIDE COMPELLING EVIDENCE TO SUPPORT THE PROPOSED LIFE CYCLE OF P. BRASSICAE, MAKING IT MORE CONVINCING AND ACCEPTABLE TO THE COMMUNITY, " EXPLAINED LIU.... view more 

CREDIT: LIJANG LIU

Found in more than 60 countries, cruciferous clubroot disease is one of the most destructive plant diseases, causing so-called tumors on the roots of Brassicaceae crops and resulting in huge yield losses annually. The causal agent of this disease, Plasmodiophora brassicae, was first discovered by Russian biologist M. S. Woronin in 1878. Despite this early discovery, the life history of the pathogen remains a mystery.

"Although P. brassicae has been identified as the causal agent of cruciferous clubroot disease for 142 years, much earlier than the discovery of most plant pathogens, we were astonished that the full life cycle of this pathogen remained unclear when we started our investigation on this plant disease in 2015," said Lijang Liu, a scientist based at the University of Saskatchewan and the Chinese Academy of Agricultural Sciences. "The limited knowledge of P. brassicae biology greatly hinders the progress of studies on the cruciferous clubroot disease, which drove us to conduct this research."

The life history of the pathogen is very complex, comprising many different life forms. Liu and colleagues clarified the life history of P. brassicae in the root tissues of host Arabidopsis in a recently published article.

"Using confocal and electron microscopic imaging, we provide compelling evidence to support the proposed life cycle of P. brassicae, making it more convincing and acceptable to the community," explained Liu. "Notably, and most surprisingly, we discovered the existence of a sexual life stage of P. brassicae, starting from the fusion of two secondary zoospores within the infected epidermal cells."

Their other major findings include defining the development of zoosporangia and secondary zoospores and the sexual behavior between secondary zoospores in root epidermal cells and elucidating the growth and development of secondary plasmodia in root cortical cells, as well as the resultant physiological disturbances to host cortical cells.

"This research provides a fundamental understanding of the pathogen's biology as well as its cellular interactions with host plants. The knowledge gained from this investigation may further illuminate cellular mechanisms underlying host resistance and susceptibility and offers insights into the management practices against clubroot disease," said Liu. "Our article will help readers understand how such a lower eukaryotic microorganism performs a complex and sophisticated life history, giving a rise to a 'tumor' disease on plant roots."

Their article also highlights microscopic techniques coupled with live microbial fluorescence staining, which can be widely used in studying host-pathogen interactions. For more information, read "Refining the Life Cycle of Plasmodiophora brassicae" published in the October issue of Phytopathology.

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Study finds evidence of neurobiological mechanism for hallucinations and delusions

COLUMBIA UNIVERSITY IRVING MEDICAL CENTER

Research News

 

A new study from researchers at Columbia University Vagelos College of Physicians and Surgeons has found evidence of a potential neurobiological mechanism for hallucinations and delusions that fits within the hierarchical model of psychosis and can explain their clinical presentation.

The study was published in eLife.

Columbia researchers Kenneth Wengler, PhD, a Postdoctoral Research Fellow and Guillermo Horga, MD, PhD, Florence Irving Associate Professor of Psychiatry, investigated the neurobiological mechanisms of two symptoms of schizophrenia: hallucinations and delusions. These two symptoms form the syndrome of psychosis, an immensely disabling psychiatric condition where patients lose their ability for reality testing.

"Typically, patients with more severe hallucinations also have more severe delusions, and these two symptoms respond similarly to antipsychotic medications. But this is not always the case; some patients have very prominent hallucinations but less severe delusions and vice versa," says Wengler. "This suggests that these symptoms may share a common neurobiological mechanism while simultaneously depending on symptom-specific pathways."

Some experts in the field believe that a hierarchical perceptual-inference model can explain the mechanisms behind psychosis. Wengler explains, "In its simplest form, the hierarchical model has two levels to the hierarchy: low and high. The low level makes inferences about basic features of stimuli and the high level makes inferences about their causes. An intuitive example of this is inferring the weather. In this scenario, you must decide if you are going to take an umbrella with you when you leave the house. The stimulus in this scenario is what you see when you look out the window; let's say it's cloudy. The context in this scenario is what you expect the weather to be like on a given day in the city you are in; let's say you are in Seattle. Although it is not currently raining, because it's cloudy and you are in a city where it often rains, you may decide to take an umbrella with you. The hierarchical model of psychosis frames hallucinations as resulting from dysfunction at the lower levels of the hierarchy and delusions as resulting from dysfunction at the higher levels of the hierarchy. Critically, these levels of inference are distinct but interconnected, so a dysfunction at one level would likely propagate upwards or downwards to other levels, therefore explaining why these symptoms tend to co-occur."

To investigate the neurobiological mechanisms of hallucinations and delusions within the framework of the hierarchical model, the researchers used functional magnetic resonance imaging to measure intrinsic neural timescales throughout the brain. These neural timescales reflect how long information is integrated in a given brain region. Most importantly, these neural timescales are organized hierarchically, making it a fitting measure to test the hierarchical model of psychosis.

The researchers collected data from 127 patients with schizophrenia from various online databases and determined how an individual's neural timescales related to their hallucination and delusion severities together. They found that neural timescales in the lower levels of the hierarchy tended to be longer in patients with more severe hallucinations, while neural timescales in the higher levels tended to be longer in patients with more severe delusions. These results provide the first direct evidence of a potential neurobiological mechanism for hallucinations and delusions that fits within the hierarchical model of psychosis and can explain their clinical presentation. The common neurobiological mechanism for both symptoms could result in increased neural timescales, but the symptom-specific pathways are the level of the hierarchy at which the neural timescales are increased. "Our findings open the door for the development of treatments to target specific symptoms of psychosis depending on an individual subject's symptom profile, in line with the current push for individualized medicine," says Horga.

The paper is titled "Distinct Hierarchical Alterations of Intrinsic Neural Timescales Account for Different Manifestations of Psychosis."

###

Additional authors are Andrew Goldberg (New York State Psychiatric Institute, New York, NY) and George Chahine, MD (Yale University, New Haven, CT).

The study was supported by grants from the

National Institute of Mental Health (R01MH117323 and R01MH114965).

The authors report no financial or other conflicts of interest.

The Columbia University Department of Psychiatry is among the top ranked psychiatry departments in the nation and has contributed greatly to the understanding and treatment of brain disorders. Co-located at the New York State Psychiatric Institute on the NewYork-Presbyterian Hospital/Columbia University Irving Medical Center campus in Washington Heights, the department enjoys a rich and productive collaborative relationship with physicians in various disciplines at the Columbia University Vagelos College of Physicians and Surgeons. Columbia Psychiatry is home to distinguished clinicians and researchers noted for their clinical and research advances in the diagnosis and treatment of depression, suicide, schizophrenia, bipolar and anxiety disorders, eating disorders, substance use disorders, and childhood psychiatric disorders.

Columbia University Irving Medical Center provides international leadership in basic, preclinical, and clinical research; medical and health sciences education; and patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the Vagelos College of Physicians and Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Columbia University Irving Medical Center is home to the largest medical research enterprise in New York City and State and one of the largest faculty medical practices in the Northeast. For more information, visit cuimc.columbia.edu or columbiadoctors.org.

 ARACHNOPHOBIA TRIGGER

Environmental factors affect the distribution of Iberian spiders

Climate, geography and endemism of Iberian spiders

UNIVERSITY OF BARCELONA

Research News

 

IMAGE: THE STUDY LED BY THE UB AND IBRIO REVEALS HOW ENVIRONMENTAL FACTORS AFFECT THE DISTRIBUTION OF BIODIVERSITY OF SPIDERS IN THE PENINSULAR TERRITORY. view more 

CREDIT: JAGOBA MALUMBRES-OLARTE, UNIVERSITY OF THE AZORES (PORTUGAL)

Southern small-leaved oak forests are the habitats with a higher level of spider endemism in the Iberian Peninsula, according to an article published in the journal Biodiversity and Conservation. The study analyses the factors that affect biodiversity patterns of spider communities in the national park network of Spain, and explains the role of the environmental factors in the distribution of the biodiversity of this faunistic group in the peninsular territory.

The study is led by Professor Miquel Arnedo, from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona, and it counts on the participation of the experts Luis Carlos Crespo, Marc Domènec and Carles Ribera (UB-IRBio), Jagoba Malumbres-Olarte and Pedro Cardoso, from the University of the Azores (Portugal), and Jordi Moya-Laraño, from the Experimental Station of Arid Zones in Almeria (EEZA-CSIC).

Iberian spiders: how are they distributed throughout the peninsular territory?

There are many doubts on the biology and ecology of Iberian spider communities, a group with a fundamental role in natural ecosystems. There might be more than 1,400 species in the peninsular territory, which has a great climate diversity and natural habitat. In some cases, there are species with a limited distribution -regional or local endemism- and this would explain the observed changes among the communities of different areas.

The new study focuses on the study of spider communities in the national parks of Aigüestortes i Estany de Sant Maurici, Ordesa y Monte Perdido, Picos de Europa, Monfragüe, Cabañeros and Sierra Nevada. In particular, they studied the spider communities -a total of 20,552 specimens from 375 species- in different types of oak trees (Quercus spp), widely distributed around the peninsula, such as those that include the sessile oak (Quercus petraea), the Valencian oak (Quercus faginea) and the Pyrinean oak (Quercus pyrenaica).

"The results reveal that Valencian oak forests (Q. faginea) are those with a higher number of spider species, probably due to the combined effects of the physical structure of the habitat and climate conditions", notes Professor Miquel Arnedo, from the Department of Evolutionary Biology, Ecology and Environmental Sciences.

The study also confirms the previous studies that point to a decrease of species in southern forest ecosystems, which is caused by the reduction of connectivity of ecosystems with the rest of the continent.

"However, we suggest that these changes in the number of species could be the result of complex interactions between the geographical position, habitat and local climate. This would make it possible, for instance, for us to find spider communities in the Cabañeros National Park (Castilla - La Mancha) with a higher number of species than in Picos de Europa (Asturias)", notes Arnedo.

Climate, geography and endemism of Iberian spiders

Another relevant contribution of the study is the identification of a pattern that relates the increase of the level of endemism in the spider communities with the rise of temperatures and decrease of annual precipitation, which are typical from the Mediterranean climate.

"Spider communities in Mediterranean areas seem to be more endemic -when we consider distributions of all species in each community- and have a higher number of exclusively Iberian species", notes the expert Jagoba Malumbres-Olarte, first signatory of the article. Other groups of spiders show a higher level of endemism depending on certain ecological features, according to the authors.

"In this case, we saw that those spiders that spread more frequently through the air using silk, known as ballooning, show a more extensive geographical distribution and therefore, are less endemic. For instance, this would be the case of some species from the Lindyphiidae family".

Spiders, indicators of environmental quality

Despite the ecological value of spiders, these arthropods have been rarely used as bioindicators. This study sheds light in this field of ecology studies, and suggests that the presence and abundance of spider families with high levels of endemism -for instance, Oonopidae, Dysderidae, Zodariidae and Sparassidae families- could be used by researchers as indicators of the singularities and ecological qualities of some natural areas.

"In the studied communities, these families are those with a higher level of endemism. If we consider the difficulty when identifying certain Iberian species and the likelihood to find undescribed species, the option of using spider families -instead of species- could ease the use of spiders as ecological and conservation indicators", authors say.

Improving biodiversity conservation strategies

The lack of many experts able to identify and describe spider species and the great diversity of this group are factors that make it difficult for researchers to study the ecology of Iberian spider communities, and by extension, many others. Expanding the knowledge on the biodiversity of the peninsular spider fauna requires the promotion of monitoring programs and a regular control of temporary changes in the communities.

In this context, the published article in the journal Biodiversity and Conservation brings new information to improve the conservation and management of national parks and protected areas in general. It reveals new data on the number and composition of species in the communities in the national parks, information that enables having a reference for future monitoring plans. Also, it identifies the most relevant groups depending on their endemic levels (that is, those with potentially high values for conservation).

"Our study also states that different habitats within the same area or park could have a differential value regarding conservation and scientific interest, and consequently, they could be an object of several levels of prioritization in conservation actions", conclude the researchers.

Infection by parasites disturbs flight behaviour in shoals of fish

Biologists study social responsiveness in fish

UNIVERSITY OF MÜNSTER

Research News

 

IMAGE: INFECTION BY PARASITES DISTURBS FLIGHT BEHAVIOUR IN SHOALS OF FISH. view more 

CREDIT: WWU/JÖRN SCHARSACK

In order to escape predators, many fish - including insects, fish and birds - have developed strategies for rapidly transmitting information on threats to others of their species. This information is transmitted within a group of hundreds, or even thousands, of individuals in (escape) waves. This collective response is also, in the case of fish, known as shoal behaviour. Special parasites can, however, manipulate such a survival strategy. Researchers at the University of Münster have discovered that infected individual fish disturb the transmission of flight behaviour and, as a result, increase not only their own risk of being eaten, but also that of other - non-infected - members of the group. The results of the study have been published in the journal Proceedings of the Royal Society.

Background and methodology

In order to study social responsiveness in fish, the researchers used the tapeworm Schistocephalus solidus as a parasite. The three-spined stickleback Gasterosteus aculeatus - an important model in ecological and evolutionary parasitology - was used as an intermediate host. The parasite ensures that the fish is less prone to be scared and more courageous and, as a result, increases its risk-taking behaviour. This poses the threat that the stickleback will very probably fall prey to the final host of the parasite, a fish-eating bird. In aquariums the scientists simulated a bird strike on shoals of sticklebacks. "When the shoal consisted only of healthy - in other words, non-infected - sticklebacks, the escape wave continued quickly through the entire shoal after the bird strike, even though the sticklebacks at the back were only able to see the response of their conspecifics and not the bird strike itself", explains Nicolle Demandt from the Institute of Evolution and Biodiversity at the University of Münster and lead author of the study. "When we placed infected sticklebacks in the middle of the shoal, the escape wave came to a virtual halt and it only got through to the fish at the back to a limited extent."

Although the manipulation of behaviour on the part of parasites is widespread in the animal kingdom, many studies carried out so far have only concentrated on the infected animals themselves and on the manipulation of their behaviour. "Ours is the first experimental study which shows how individuals whose behaviour has been manipulated by parasites can influence the transmission of information and, as a result, collective flight responses - in other words, shoal behaviour," explains Prof. Joachim Kurtz, in whose laboratory the study was carried out. The researchers examined the connection between parasitic infection and flight depth, as well as the time the fish spent in the danger zone before and after the bird strike.

Sticklebacks with a high parasitic infection displayed a tendency to take flight to not such a deep level and they remained in the danger zone for a longer period of time than did sticklebacks with less parasitic infection. "The result indicates that the loss of energy might play a role in the extent to which behaviour is manipulated," explains Dr. Jörn Scharsack, who led the study. "Parasites remove energy from their hosts, which leads for example to a reduction in fat reserves and a higher food requirement. Infected fish should therefore invest less energy in flight response and return more quickly to looking for food."

As sticklebacks are found in very different aquatic systems - e.g. clear lakes, turbid rivers and sea environments - transferring the results of the study to the fishes' natural habitats depends on the local surroundings. In clear waters, the results can indeed be transferred to the natural habitat as the fish use their eyes to react to the signals from other sticklebacks taking flight. In more turbid surroundings, however, the fish can rely more on other senses. For example, by means of their lateral line organs they can feel even the smallest changes in pressure caused by the movements made by their neighbours in the shoal. Other factors influencing the transfer of the laboratory study to a natural environment are the size of the shoal, the number of infected individuals and the extent of their parasitic infection.

Should it be a general phenomenon that infected individuals have an influence on the collective responses of the entire group, this might be of wide-ranging significance for the animal kingdom - even including a possible influence of parasites on human group behaviour, say the researchers.

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Soldiers benefit from psychological health research

Army scientists develop training to mitigate misdirected anger, aggression

U.S. ARMY RESEARCH LABORATORY

Research News

 

ADELPHI, Md. -- Army scientists developed computer-based training to help Soldiers avoid unnecessary social conflict and mitigate anger-related outcomes.

Scientists at the U.S. Army Combat Capabilities Development Command's, now referred to as DEVCOM, Army Research Laboratory and the Walter Reed Army Institute for Research, developed a Hostile Bias Modification Training protocol to reduce hostile attribution bias, anger and reactive aggression in ambiguous social conflict situations, which can jeopardize social bonds, relationships with significant others, team culture and performance.

"This was a unique across agency collaborative effort bringing together clinical psychology and cognitive science Army researchers to investigate reactive aggressive behavior," said Army researcher Dr. Sue Kase. "After reading an Institute of Electrical and Electronics Engineers conference publication on social bias factors associated with information transmission, Capt. Jeffery Osgood of WRAIR contacted the ARL co-authors for assistance."

At the time, in 2018, the laboratory was very fortunate to have the effort and crowdsourcing platform resources available to respond immediately to Osgood's request, Kase said.

This established a scientific alliance between the organizations by translating WRAIR's research needs to fit one of the laboratory's ongoing internal research methodologies--technological advances in large scale online data collection.

"Osgood's team brought clinical psychology expertise to the table while we offered our expertise in large scale crowdsourcing experimentation in cognitive behavior," Kase said. "When a partner agency requests our assistance, it is important to think outside the box because the potential impact could be significant and directly transition to the welfare of the Soldier. As in this case, the research will improve the psychological health of Soldiers both in the field and in post-service."

The study consisted of two crowdsourced experiments investigating if HBMT could reduce overall hostile attribution bias as well as perceived hostility, anger and aggression.

HBMT exposed participants to three types of word fragments: ambiguous, aggressive and non-aggressive. Participants were instructed to only form non-aggressive words and not respond in other cases.

Next, participants reacted to vignettes where in some cases the wrongdoer was clearly hostile while in others it was ambiguous.

Participants returned after several days to complete the second part of the study on real-world situations such as driving and social media behavior.

The results of the study, published in the journal Cognitive Therapy and Research, indicate that HBMT was effective in reducing hostile attribution bias, anger and reactive aggression in ambiguous situations.

"Most importantly, these effects appear to extend beyond the laboratory to real world aggression including aggressive driving and virtual aggression on social media," Kase said. "The effects sustained for the entire duration of the study (up to 96 hours). HBMT appears to be an easily implemented intervention to mitigate anger-related outcomes and its online delivery would enable mobile use in the field."

While the results of the study are very promising, the research team said there is more work to be done moving in to the future.

"Though more research is needed, we believe that HBMT could be effective as both a standalone tool for use at home, in field settings, or in concert with other therapeutic options to help mitigate unwarranted anger and aggression," Osgood said. "We are excited about HBMT's potential to both prevent and treat behavioral health concerns."

Kase said that the research team believes this research will positively impact Soldiers operating in both non-hostile and hostile environments.

"Positive team dynamics and task performance are critical when working in close coordination during challenging critical missions," Kase said. "Unwarranted anger in these types of situations can degrade individual team member cognitive processes and physical performance and potentially lead to violence-related consequences. Results from the study help us understand more about unwarranted aggressive behavior and, more generally, contribute to improving the psychological health of Soldiers, including those who have separated from the service. The knowledge gained is applicable to avoiding unnecessary social conflict and mitigating anger-related outcomes in both operational field settings and civilian populated areas."

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