Abstract
We use very long baseline interferometry to measure the proper motions of three black hole X-ray binaries (BHXBs). Using these results together with data from the literature and Gaia DR2 to ...collate the best available constraints on proper motion, parallax, distance, and systemic radial velocity of 16 BHXBs, we determined their three-dimensional Galactocentric orbits. We extended this analysis to estimate the probability distribution for the potential kick velocity (PKV) a BHXB system could have received on formation. Constraining the kicks imparted to BHXBs provides insight into the birth mechanism of black holes (BHs). Kicks also have a significant effect on BH–BH merger rates, merger sites, and binary evolution, and can be responsible for spin–orbit misalignment in BH binary systems. 75 per cent of our systems have potential kicks $\gt 70\, \rm {km\,s^{-1}}$. This suggests that strong kicks and hence spin–orbit misalignment might be common among BHXBs, in agreement with the observed quasi-periodic X-ray variability in their power density spectra. We used a Bayesian hierarchical methodology to analyse the PKV distribution of the BHXB population, and suggest that a unimodal Gaussian model with a mean of 107 $\pm \,\,16\, \rm {km\,s^{-1}}$ is a statistically favourable fit. Such relatively high PKVs would also reduce the number of BHs likely to be retained in globular clusters. We found no significant correlation between the BH mass and PKV, suggesting a lack of correlation between BH mass and the BH birth mechanism. Our python code allows the estimation of the PKV for any system with sufficient observational constraints.
The first two orbits of the Parker Solar Probe spacecraft have enabled the first in situ measurements of the solar wind down to a heliocentric distance of 0.17 au (or 36 ). Here, we present an ...analysis of this data to study solar wind turbulence at 0.17 au and its evolution out to 1 au. While many features remain similar, key differences at 0.17 au include increased turbulence energy levels by more than an order of magnitude, a magnetic field spectral index of −3/2 matching that of the velocity and both Elsasser fields, a lower magnetic compressibility consistent with a smaller slow-mode kinetic energy fraction, and a much smaller outer scale that has had time for substantial nonlinear processing. There is also an overall increase in the dominance of outward-propagating Alfvénic fluctuations compared to inward-propagating ones, and the radial variation of the inward component is consistent with its generation by reflection from the large-scale gradient in Alfvén speed. The energy flux in this turbulence at 0.17 au was found to be ∼10% of that in the bulk solar wind kinetic energy, becoming ∼40% when extrapolated to the Alfvén point, and both the fraction and rate of increase of this flux toward the Sun are consistent with turbulence-driven models in which the solar wind is powered by this flux.
A panel of national experts was convened by the Infectious Diseases Society of America (IDSA) to update the 2005 guidelines for the treatment of skin and soft tissue infections (SSTIs). The panel's ...recommendations were developed to be concordant with the recently published IDSA guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections. The focus of this guideline is the diagnosis and appropriate treatment of diverse SSTIs ranging from minor superficial infections to life-threatening infections such as necrotizing fasciitis. In addition, because of an increasing number of immunocompromised hosts worldwide, the guideline addresses the wide array of SSTIs that occur in this population. These guidelines emphasize the importance of clinical skills in promptly diagnosing SSTIs, identifying the pathogen, and administering effective treatments in a timely fashion.
Marine spatial planning (MSP) seeks to reduce conflicts and environmental impacts, and promote sustainable use of marine ecosystems. Existing MSP approaches have successfully determined how to ...achieve target levels of ocean area for particular uses while minimizing costs and impacts, but they do not provide a framework that derives analytical solutions in order to co-ordinate siting of multiple uses while balancing the effects of planning on each sector in the system. We develop such a framework for guiding offshore aquaculture (bivalve, finfish, and kelp farming) development in relation to existing sectors and environmental concerns (wild-capture fisheries, viewshed quality, benthic pollution, and disease spread) in California, USA. We identify > 250,000 MSP solutions that generate significant seafood supply and billions of dollars in revenue with minimal impacts (often < 1%) on existing sectors and the environment. We filter solutions to identify candidate locations for high-value, low-impact aquaculture development. Finally, we confirm the expectation of substantial value of our framework over conventional planning focused on maximizing individual objectives.
Abstract
The Greenland Ice Sheet harbours a wealth of microbial life, yet the total biomass stored or exported from its surface to downstream environments is unconstrained. Here, we quantify ...microbial abundance and cellular biomass flux within the near-surface weathering crust photic zone of the western sector of the ice sheet. Using groundwater techniques, we demonstrate that interstitial water flow is slow (~10
−2
m d
−1
), while flow cytometry enumeration reveals this pathway delivers 5 × 10
8
cells m
−2
d
−1
to supraglacial streams, equivalent to a carbon flux up to 250 g km
−2
d
−1
. We infer that cellular carbon accumulation in the weathering crust exceeds fluvial export, promoting biomass sequestration, enhanced carbon cycling, and biological albedo reduction. We estimate that up to 37 kg km
−2
of cellular carbon is flushed from the weathering crust environment of the western Greenland Ice Sheet each summer, providing an appreciable flux to support heterotrophs and methanogenesis at the bed.
AIM: To assess the extent to which humans have reshaped Earth's biodiversity, by estimating natural ranges of all late Quaternary mammalian species, and to compare diversity patterns based on these ...with diversity patterns based on current distributions. LOCATION: Globally. METHODS: We estimated species, functional and phylogenetic diversity patterns based on natural ranges of all mammalian species (n = 5747 species) as they could have been today in the complete absence of human influence through time. Following this, we compared macroecological analyses of current and natural diversity patterns to assess whether human‐induced range changes bias evolutionary and ecological analyses based on current diversity patterns. RESULTS: We find that current diversity patterns have been drastically modified by humans, mostly due to global extinctions and regional to local extirpations. Current and natural diversities exhibit marked deviations virtually everywhere outside sub‐Saharan Africa. These differences are strongest for terrestrial megafauna, but also important for all mammals combined. The human‐induced changes led to biases in estimates of environmental diversity drivers, especially for terrestrial megafauna, but also for all mammals combined. MAIN CONCLUSIONS: Our results show that fundamental diversity patterns have been reshaped by human‐driven extinctions and extirpations, highlighting humans as a major force in the Earth system. We thereby emphasize that estimating natural distributions and diversities is important to improve our understanding of the evolutionary and ecological drivers of diversity as well as for providing a benchmark for conservation.
The provision of nutrition care by doctors is important in promoting healthy dietary habits, and such interventions can lead to reductions in disease morbidity, mortality, and medical costs. However, ...medical students and doctors report inadequate nutrition education and preparedness during their training at school. Previous studies investigating the inadequacy of nutrition education have not sufficiently evaluated the perspectives of students. In this study, students' perspectives on doctors' role in nutrition care, perceived barriers, and strategies to improve nutrition educational experiences are explored.
A total of 23 undergraduate clinical level medical students at the 5th to final year in the School of Medicine and Health Sciences of the University for Development Studies in Ghana were purposefully selected to participate in semi-structured individual interviews. Students expressed their opinions and experiences regarding the inadequacy of nutrition education in the curriculum. Each interview was audio-recorded and later transcribed verbatim. Using the constant comparison method, key themes were identified from the data and analysis was done simultaneously with data collection.
Students opined that doctors have an important role to play in providing nutrition care to their patients. However, they felt their nutrition education was inadequate due to lack of priority for nutrition education, lack of faculty to provide nutrition education, poor application of nutrition science to clinical practice and poor collaboration with nutrition professionals. Students opined that their nutrition educational experiences will be improved if the following strategies were implemented: adoption of innovative teaching and learning strategies, early and comprehensive incorporation of nutrition as a theme throughout the curriculum, increasing awareness on the importance of nutrition education, reviewing and revision of the curriculum to incorporate nutrition, and involving nutrition/dietician specialists in medical education.
Though students considered nutrition care as an important role for doctors they felt incapacitated by non-prioritisation of nutrition education, lack of faculty for teaching of nutrition education, poor application of nutrition science and poor collaboration with nutrition professionals. Incorporation of nutrition as a theme in medical education, improving collaboration, advocacy and creating enabling environments for nutrition education could address some of the barriers to nutrition education.
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