1,130 research outputs found
Mandatory Continuing Education: Does It Really Protect Society from Incompetent Health Professionals
Although the focus is narrow, this article argues that, in the face of short half-lives of current knowledge, continuing education requirements are needed and suggests possible improvements in the way that continuing education is implemented. While the issue is not explicitly addressed, readers might ponder whether such requirements might be profitably extended to other disciplines
The Role of Cyclone Activity in Snow Accumulation on Arctic Sea Ice
Identifying the mechanisms controlling the timing and magnitude of snow accumulation on sea ice is crucial for understanding snows net effect on the surface energy budget and sea-ice mass balance. Here, we analyze the role of cyclone activity on the seasonal buildup of snow on Arctic sea ice using model, satellite, and in situ data over 19792016. On average, 44% of the variability in monthly snow accumulation was controlled by cyclone snowfall and 29% by sea-ice freeze-up. However, there were strong spatio-temporal differences. Cyclone snowfall comprised ~50% of total snowfall in the Pacific compared to 83% in the Atlantic. While cyclones are stronger in the Atlantic, Pacific snow accumulation is more sensitive to cyclone strength. These findings highlight the heterogeneity in atmosphere-snow-ice interactions across the Arctic, and emphasize the need to scrutinize mechanisms governing cyclone activity to better understand their effects on the Arctic snow-ice system with anthropogenic warming
Real-Time Eye-to-Eye Contact Is Associated With Cross-Brain Neural Coupling in Angular Gyrus
Direct eye contact between two individuals is a salient social behavior known to initiate and promote interpersonal interaction. However, the neural processes that underlie these live interactive behaviors and eye-to-eye contact are not well understood. The Dynamic Neural Coupling Hypothesis presents a general theoretical framework proposing that shared interactive behaviors are represented by cross-brain signal coherence. Using functional near-infrared spectroscopy (fNIRS) adapted for hyper scanning, we tested this hypothesis specifically for neural mechanisms associated with eye-to-eye gaze between human participants compared to similar direct eye-gaze at a dynamic video of a face and predicted that the coherence of neural signals between the two participants during reciprocal eye-to-eye contact would be greater than coherence observed during direct eye-gaze at a dynamic video for those signals originating in social and face processing systems. Consistent with this prediction cross-brain coherence was increased for signals within the angular gyrus (AG) during eye-to-eye contact relative to direct eye-gaze at a dynamic face video (p < 0.01). Further, activity in the right temporal-parietal junction (TPJ) was increased in the real eye-to-eye condition (p < 0.05, FDR corrected). Together, these findings advance a functional and mechanistic understanding of the AG and cross-brain neural coupling associated with real-time eye-to-eye contact
Female Salix viminalis are more severely infected by Melampsora spp. but neither sex experiences associational effects
Associational effects of plant genotype or species on plant biotic interactions are common, not least for disease spread, but associational effects of plant sex on interactions have largely been ignored. Sex in dioecious plants can affect biotic interactions with herbivores and pollinators; however, its effects on plant-pathogen interactions are understudied and associational effects are unknown. In a replicated field experiment, we assessed Melampsora spp. leaf rust infection in monosexual and mixed sex plots of dioecious Salix viminalis L. to determine whether plant sex has either direct or associational effects on infection severity. We found no differences in Melampsora spp. infection severity among sexual monocultures and mixtures in our field experiment. However, female plants were overall more severely infected. In addition, we surveyed previous studies of infection in S. viminalis clones and reevaluated the studies after we assigned sex to the clones. We found that females were generally more severely infected, as in our field study. Similarly, in a survey of studies on sexbiased infection in dioecious plants, we found more female-biased infections in plant-pathogen pairs. We conclude that there was no evidence for associational plant sex effects of neighboring conspecifics for either females or males on infection severity. Instead, plant sex effects on infection act at an individual plant level. Our findings also suggest that female plants may in general be more severely affected by fungal pathogens than males
Beyond Spheroids and Discs: Classifications of CANDELS Galaxy Structure at 1.4 < z < 2 via Principal Component Analysis
Important but rare and subtle processes driving galaxy morphology and
star-formation may be missed by traditional spiral, elliptical, irregular or
S\'ersic bulge/disk classifications. To overcome this limitation, we use a
principal component analysis of non-parametric morphological indicators
(concentration, asymmetry, Gini coefficient, , multi-mode, intensity
and deviation) measured at rest-frame -band (corresponding to HST/WFC3 F125W
at 1.4 ) galaxy morphologies. Principal component analysis (PCA) quantifies
the correlations between these morphological indicators and determines the
relative importance of each. The first three principal components (PCs) capture
75 per cent of the variance inherent to our sample. We interpret the
first principal component (PC) as bulge strength, the second PC as dominated by
concentration and the third PC as dominated by asymmetry. Both PC1 and PC2
correlate with the visual appearance of a central bulge and predict galaxy
quiescence. PC1 is a better predictor of quenching than stellar mass, as as
good as other structural indicators (S\'ersic-n or compactness). We divide the
PCA results into groups using an agglomerative hierarchical clustering method.
Unlike S\'ersic, this classification scheme separates compact galaxies from
larger, smooth proto-elliptical systems, and star-forming disk-dominated clumpy
galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing
between these galaxy structural types in a quantitative manner is an important
step towards understanding the connections between morphology, galaxy assembly
and star-formation.Comment: 31 pages, 24 figures, accepted for publication in MNRA
Canine sterile steroid-responsive lymphadenitis in 49 dogs
OBJECTIVES:To report clinical and laboratory features, treatment responses and outcome in dogs diagnosed with sterile steroid-responsive lymphadenitis in the United Kingdom. MATERIALS AND METHODS:Medical records of dogs diagnosed with sterile steroid-responsive lymphadenitis from 2009 to 2016 at six specialist referral centres were evaluated retrospectively. RESULTS:The study included 49 dogs. Springer spaniels appeared to be over-represented (16 of 49 dogs). Young dogs (median age: 3 years and 9 months) and females (31 of 49) were frequently affected. Clinical presentation was variable, with pyrexia (39 of 49), lethargy (35 of 49) and anorexia (21 of 49) the most commonly reported clinical signs. Lymph node cytology or histopathology demonstrated neutrophilic, pyogranulomatous, granulomatous or necrotising lymphadenitis without a detectable underlying cause in all cases. Because a sterile immune-mediated aetiology was suspected, all dogs received prednisolone, which was followed by rapid resolution of clinical signs and lymphadenopathy in most cases. CLINICAL SIGNIFICANCE:Sterile steroid-responsive lymphadenitis should be considered in dogs with pyrexia of unknown origin with inflammatory lymphadenopathy if no underlying cause can be found and often responds well to immunosuppressive corticosteroid therapy
Biallelic Loss-of-Function Variants in BICD1 Are Associated with Peripheral Neuropathy and Hearing Loss
Hearing loss and peripheral neuropathy are two clinical entities that are genetically and phenotypically heterogeneous and sometimes co-occurring. Using exome sequencing and targeted segregation analysis, we investigated the genetic etiology of peripheral neuropathy and hearing loss in a large Ashkenazi Jewish family. Moreover, we assessed the production of the candidate protein via western blotting of lysates from fibroblasts from an affected individual and an unaffected control. Pathogenic variants in known disease genes associated with hearing loss and peripheral neuropathy were excluded. A homozygous frameshift variant in the BICD1 gene, c.1683dup (p.(Arg562Thrfs*18)), was identified in the proband and segregated with hearing loss and peripheral neuropathy in the family. The BIDC1 RNA analysis from patient fibroblasts showed a modest reduction in gene transcripts compared to the controls. In contrast, protein could not be detected in fibroblasts from a homozygous c.1683dup individual, whereas BICD1 was detected in an unaffected individual. Our findings indicate that bi-allelic loss-of-function variants in BICD1 are associated with hearing loss and peripheral neuropathy. Definitive evidence that bi-allelic loss-of-function variants in BICD1 cause peripheral neuropathy and hearing loss will require the identification of other families and individuals with similar variants with the same phenotype
Atypical disengagement from faces and its modulation by the control of eye fixation in children with Autism Spectrum Disorder
By using the gap overlap task, we investigated disengagement from faces and objects in children (9–17 years old) with and without autism spectrum disorder (ASD) and its neurophysiological correlates. In typically developing (TD) children, faces elicited larger gap effect, an index of attentional engagement, and larger saccade-related event-related potentials (ERPs), compared to objects. In children with ASD, by contrast, neither gap effect nor ERPs differ between faces and objects. Follow-up experiments demonstrated that instructed fixation on the eyes induces larger gap effect for faces in children with ASD, whereas instructed fixation on the mouth can disrupt larger gap effect in TD children. These results suggest a critical role of eye fixation on attentional engagement to faces in both groups
Observational evidence for cosmological coupling of black holes and its implications for an astrophysical source of dark energy
Observations have found black holes spanning ten orders of magnitude in mass
across most of cosmic history. The Kerr black hole solution is however
provisional as its behavior at infinity is incompatible with an expanding
universe. Black hole models with realistic behavior at infinity predict that
the gravitating mass of a black hole can increase with the expansion of the
universe independently of accretion or mergers, in a manner that depends on the
black hole's interior solution. We test this prediction by considering the
growth of supermassive black holes in elliptical galaxies over
. We find evidence for cosmologically coupled mass growth among
these black holes, with zero cosmological coupling excluded at 99.98%
confidence. The redshift dependence of the mass growth implies that, at
, black holes contribute an effectively constant cosmological
energy density to Friedmann's equations. The continuity equation then requires
that black holes contribute cosmologically as vacuum energy. We further show
that black hole production from the cosmic star formation history gives the
value of measured by Planck while being consistent with
constraints from massive compact halo objects. We thus propose that stellar
remnant black holes are the astrophysical origin of dark energy, explaining the
onset of accelerating expansion at .Comment: 10 pages, 3 figures, published in ApJ Letter
Altered postural sway in patients suffering from non-specific neck pain and whiplash associated disorder - A systematic review of the literature
To assess differences in center of pressure (COP) measures in patients suffering from non-specific neck pain (NSNP) or whiplash-associated disorder (WAD) compared to healthy controls and any relationship between changes in postural sway and the presence of pain, its intensity, previous pain duration and the perceived level of disability. Summary of Background data: Over the past 20 years, the center of pressure (COP) has been commonly used as an index of postural stability in standing. While several studies investigated COP excursions in neck pain and WAD patients and compared these to healthy individuals, no comprehensive analysis of the reported differences in postural sway pattern exists. Search methods: Six online databases were systematically searched followed by a manual search of the retrieved papers. Selection Criteria: Papers comparing COP measures derived from bipedal static task conditions on a force plate of non-specific neck pain and WAD sufferers to those of healthy controls. Data collection and analysis: Two reviewers independently screened titles and abstracts for relevance. Screening for final inclusion, data extraction and quality assessment were carried out with a third reviewer to reconcile differences
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