bluuebunny/crossref_metadata_2025_split huggingface dataset:
A revision of the bioregionalisation of freshwater fish communities in the Australian Monsoonal Tropics
Authors: Shelley James J. , Dempster Tim , Le Feuvre Matthew C. , Unmack Peter J. , Laffan Shawn W. , Swearer Stephen E. 
Published: March 2019

AbstractThe Australian freshwater fish fauna is very unique, but poorly understood. In the Australian Monsoonal Tropics (AMT) biome of northern Australia, the number of described and candidate species has nearly doubled since the last attempt to analyse freshwater fish species composition patterns and determine a bioregionalisation scheme. Here, we utilise the most complete database of catchment‐scale freshwater fish distributions from the AMT to date to: (a) reanalyze spatial patterns of species richness, endemism and turnover of freshwater fishes; (b) propose a biogeographic regionalisation based on species turnover; (c) assess the relationship between species turnover and patterns of environmental change and historic drainage connectivity; and (d) identify sampling gaps. Biogeographic provinces were identified using an agglomerative cluster analysis of a Simpson's beta (βsim) dissimilarity matrix. A generalised dissimilarity model incorporating eighteen environmental variables was used to investigate the environmental correlates of species turnover. Observed and estimated species richness and endemism were calculated and inventory completeness was estimated based on the ratio of observed to estimated species richness. Three major freshwater fish biogeographic provinces and 14 subprovinces are proposed. These differ substantially from the current bioregionalisation scheme. Species turnover was most strongly influenced by environmental variables that are interpreted to reflect changes in terrain (catchment relief and confinement), geology and climate (runoff perenniality, stream density), and biotic responses to climate (net primary productivity). Past connectivity between rivers during low sea‐level events is also influential highlighting the importance of historical processes in explaining contemporary patterns of biodiversity in the AMT. The inclusion of 49 newly discovered species and candidate species only reinforced known focal points of species richness and endemism in the AMT. However, a number of key sampling gaps remain that need to be filled to fully characterise the proposed bioregionalisation.
Integrated population models: powerful methods to embed individual processes in population dynamics models
Authors: Plard Floriane , Fay Rémi , Kéry Marc , Cohas Aurélie , Schaub Michael 
Published: March 2019

AbstractPopulation dynamics models have long assumed that populations are composed of a restricted number of groups, where individuals in each group have identical demographic rates and where all groups are similarly affected by density‐dependent and ‐independent effects. However, individuals usually vary tremendously in performance and in their sensitivity to environmental conditions or resource limitation, such that individual contributions to population growth will be highly variable. Recent efforts to integrate individual processes in population models open up new opportunities for the study of eco‐evolutionary processes, such as the density‐dependent influence of environmental conditions on the evolution of morphological, behavioral, and life‐history traits. We review recent advances that demonstrate how including individual mechanisms in models of population dynamics contributes to a better understanding of the drivers of population dynamics within the framework of integrated population models (IPMs). IPMs allow for the integration in a single inferential framework of different data types as well as variable population structure including sex, social group, or territory, all of which can be formulated to include individual‐level processes. Through a series of examples, we first show how IPMs can be beneficial for getting more accurate estimates of demographic traits than classic matrix population models by including basic population structure and their influence on population dynamics. Second, the integration of individual‐ and population‐level data allows estimating density‐dependent effects along with their inherent uncertainty by directly using the population structure and size to feedback on demography. Third, we show how IPMs can be used to study the influence of the dynamics of continuous individual traits and individual quality on population dynamics. We conclude by discussing the benefits and limitations of IPMs for integrating data at different spatial, temporal, and organismal levels to build more mechanistic models of population dynamics.
The functional role of beta‐oscillations in the supplementary motor area during reaching and grasping after stroke: A question of structural damage to the corticospinal tract
Authors: Quandt Fanny , Bönstrup Marlene , Schulz Robert , Timmermann Jan E. , Mund Maike , Wessel Maximilian J. , Hummel Friedhelm C. 
Published: March 2019

AbstractHand motor function is often severely affected in stroke patients. Non‐satisfying recovery limits reintegration into normal daily life. Understanding stroke‐related network changes and identifying common principles that might underlie recovered motor function is a prerequisite for the development of interventional therapies to support recovery. Here, we combine the evaluation of functional activity (multichannel electroencephalography) and structural integrity (diffusion tensor imaging) in order to explain the degree of residual motor function in chronic stroke patients. By recording neural activity during a reaching and grasping task that mimics activities of daily living, the study focuses on deficit‐related neural activation patterns. The study showed that the functional role of movement‐related beta desynchronization in the supplementary motor area (SMA) for residual hand motor function in stroke patients depends on the microstructural integrity of the corticospinal tract (CST). In particular, in patients with damaged CST, stronger task‐related activity in the SMA was associated with worse residual motor function. Neither CST damage nor functional brain activity alone sufficiently explained residual hand motor function. The findings suggest a central role of the SMA in the motor network during reaching and grasping in stroke patients, the degree of functional relevance of the SMA is depending on CST integrity.
White matter and hypoxic hypobaria in humans
Authors: McGuire Stephen A. , Ryan Meghann C. , Sherman Paul M. , Sladky John H. , Rowland Laura M. , Wijtenburg S. Andrea , Hong L. Elliot , Kochunov Peter V. 
Published: March 2019

AbstractOccupational exposure to hypobaria (low atmospheric pressure) is a risk factor for reduced white matter integrity, increased white matter hyperintensive burden, and decline in cognitive function. We tested the hypothesis that a discrete hypobaric exposure will have a transient impact on cerebral physiology. Cerebral blood flow, fractional anisotropy of water diffusion in cerebral white matter, white matter hyperintensity volume, and concentrations of neurochemicals were measured at baseline and 24 hr and 72 hr postexposure in N = 64 healthy aircrew undergoing standard US Air Force altitude chamber training and compared to N = 60 controls not exposed to hypobaria. We observed that hypobaric exposure led to a significant rise in white matter cerebral blood flow (CBF) 24 hr postexposure that remained elevated, albeit not significantly, at 72 hr. No significant changes were observed in structural measurements or gray matter CBF. Subjects with higher baseline concentrations of neurochemicals associated with neuroprotection and maintenance of normal white matter physiology (glutathione, N‐acetylaspartate, glutamate/glutamine) showed proportionally less white matter CBF changes. Our findings suggest that discrete hypobaric exposure may provide a model to study white matter injury associated with occupational hypobaric exposure.
FIGO Statement: Staffing requirements for delivery care, with special reference to low‐ and middle‐income countries
Authors: Stones William , Visser Gerard H.A. , Theron Gerhard ,   the FIGO Safe Motherhood and Newborn Health Committee
Published: March 2019

AbstractInternational standards for clinical staffing of delivery care in maternity units are currently lacking, with resulting gaps in provision leading to adverse outcomes and very poor experiences of care for women and families. While evidence‐informed modelling approaches have been proposed based on population characteristics and estimated rates of complications, their application and outcomes in low‐resource settings have not been reported. Here, FIGO's Safe Motherhood and Newborn Health Committee proposes indicative standards for labor wards as a starting point for policy and program development. These standards consider the volume of deliveries, the case mix, and the need to match clinical care requirements with an appropriate mix of professional skills among midwifery and obstetric staff. The role of Shift Leader in busy labor wards is emphasized. Application of the standards can help to assure women and their families of a safe but also positive birthing experience. FIGO calls for investment by partners to test these clinically‐informed recommendations for delivery unit staffing at hospital and district level in low‐ and middle‐income country settings.
Hans Bluntschli in Berne: Researching reproduction in hedgehog tenrecs (Afrosoricida, Tenrecidae)
Authors: Carter Anthony M. 
Published: March 2019

AbstractThe Swiss anatomist Hans Bluntschli is best known as a primatologist. Yet, his focus during his later years in Berne was on reproduction in Malagasy tenrecs. This research was done with two graduate students, Robert Goetz and Fritz Strauss; all three had been obliged to leave Germany after the National Socialists came to power. Unique features of reproduction in tenrecs included nonantral follicles, intrafollicular fertilization, eversion of the corpus luteum, and polyovulation. The fertilized egg formed a blastula that developed into a blastocyst; there was no morula stage. A false placental cushion developed in the endometrium opposite the implantation site. Placentation was complex and included development of a prominent haemophagous organ. These findings are discussed in relation to current concepts of mammalian phylogeny that place tenrecs and golden moles in the same order and as close relatives to elephant shrews and the aardvark.
Observed and simulated Indian Ocean Dipole activity since the mid‐19th century and its relation to East African short rains
Authors: Thielke Anja , Mölg Thomas 
Published: March 2019

AbstractThe coupled atmosphere–ocean phenomenon in the Indian Ocean, known as the Indian Ocean Dipole (IOD) mode, shows various influences on regional tropical climates. East Africa (EA) experiences enhanced precipitation during October–December (the annual “short rains”), and therefore it was hypothesized that a shift from wetter to drier conditions in EA after 1880 documented by proxy data (e.g., lake levels, glacier size) was favoured by a decline in positive IOD frequency. However, this proposed century‐scale pattern of the IOD emerged from single data sets, while the ensemble perspective from the Coupled Model Intercomparison Project phase 5 (CMIP5) global climate model (GCM) archive is still missing. Based on rigorous test criteria that capture crucial IOD and EA climate characteristics, the present study identifies 15 runs from the CMIP5 data for the ensemble analyses. A key result of the test is that the ensemble is dominated by the GISS E2 H model (13 realizations) with a little influence from HadCM3 (2 realizations), and therefore most CMIP5 models seem unable to capture the long‐term variability of EA precipitation. The selected model realizations show a significant increase in the frequency of positive IOD events in the late 20th century, in agreement with previous research and most likely due to external climate forcing. Further frequency changes are absent in the available time series, yet we find that the precipitation excess during positive IODs was stronger in the 19th century (1860–1909) than in the recent decades (1956–2005). Both thermodynamic factors on the regional scale (convection, evaporation) and dynamical processes on the large scale (strength of the zonal tropical circulation) emerge as physical basis of this changing IOD property. The higher precipitation intensity in EA during positive IOD events in the 19th century period provides a consistent mechanism that could have contributed to the moister regional climate of that time, irrespective of IOD frequency.
Regionalization of precipitation in Mauritius: a statistical approach
Authors: Raja Nussaïbah Begum , Aydin Olgu 
Published: March 2019

AbstractThe aim of this study was to quantify the regional precipitation patterns of Mauritius using the total mean annual precipitation of 52 meteorological stations for the period 1981–2010. Principal component analysis was first used to determine the significant variables influencing precipitation in Mauritius. A cluster analysis was then applied to group the stations according to the significant variables identified. Finally, a spatial interpolation of precipitation in Mauritius using the kriging with external drift technique was carried out to examine the spatial distribution of precipitation on the island. The principal component analysis results showed that elevation and coastal proximity caused the most variance in the dataset with respect to precipitation. Using the cluster analysis and kriging results, six regions of precipitation were determined: three inland and three coastal regions. A decreasing gradient in precipitation between the southeast and northwest is observed due to the southeast trade winds and the altitudinal difference between the coastal areas and the central plateau. The central plateau represents a distinct precipitation zone which receives the highest precipitation on the island. The windward‐facing south and eastern highlands experience orographic precipitation as a result of adiabatic air expansion and therefore are more humid. On the other hand, the northeast highlands region, together with the north and western coasts which lie in the leeward rain shadow, are notably drier.
A strategy for the identification of protein architectures directly from ion mobility mass spectrometry data reveals stabilizing subunit interactions in light harvesting complexes
Authors: Kaldmäe Margit , Sahin Cagla , Saluri Mihkel , Marklund Erik G. , Landreh Michael 
Published: March 2019

AbstractBiotechnological applications of protein complexes require detailed information about their structure and composition, which can be challenging to obtain for proteins from natural sources. Prominent examples are the ring‐shaped phycoerythrin (PE) and phycocyanin (PC) complexes isolated from the light‐harvesting antennae of red algae and cyanobacteria. Despite their widespread use as fluorescent probes in biotechnology and medicine, the structures and interactions of their noncrystallizable central subunits are largely unknown. Here, we employ ion mobility mass spectrometry to reveal varying stabilities of the PC and PE complexes and identify their closest architectural homologues among all protein assemblies in the Protein Data Bank (PDB). Our results suggest that the central subunits of PC and PE complexes, although absent from the crystal structures, may be crucial for their stability, and thus of unexpected importance for their biotechnological applications.
Freezing rain in Jersey in February 1841
Authors: Le Blancq Frank 
Published: March 2019

AbstractA rare severe freezing rain event affected Jersey, Channel Islands in early February 1841, during a rather cold and snowy winter. A brief explanation is given of the atmospheric conditions and synoptic weather pattern which produce freezing rain. Contemporary diaries, local newspaper reports and other historical information were used to construct a detailed chronology of this extreme weather event. The devastating effects of the glaze on the landscape of the island, the local economy and social life are also documented.
Characterization of Air and Ground Temperature Relationships within the CMIP5 Historical and Future Climate Simulations
Authors: García‐García Almudena , Cuesta‐Valero Francisco José , Beltrami Hugo , Smerdon Jason E. 
Published: March 2019

AbstractThe relationships between air and ground surface temperatures across North America are examined in the historical and future projection simulations from 32 general circulation models (GCMs) included in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The difference between surface air (2 m) and ground surface (10 cm) temperatures is affected by simulated snow cover, vegetation cover, and precipitation by means of changes in soil moisture and soil properties. In winter, the differences between air and ground surface temperatures, for all CMIP5 simulations, are related to the insulating effect of snow cover and soil freezing phenomena. In summer, large leaf area index and large precipitation rates correspond to smaller differences between air and ground temperatures for the majority of simulations, likely due to induced changes in latent and sensible heat fluxes at the ground surface. Our results show that the representation of air‐ground coupling, analyzed using the difference between ground and air surface temperatures as metric, differs from observations, the North American Regional Reanalysis product and among the CMIP5 GCM simulations, by amounts that depend on the employed land surface model. The large variability among GCMs and the marked dependence of the results on the choice of the land surface model illustrate the need for improving the representation of processes controlling the coupling of the lower atmosphere and the land surface in GCMs as a mean of reducing the variability in their representation of weather and climate phenomena.
Geological Characterization of the Ina Shield Volcano Summit Pit Crater on the Moon: Evidence for Extrusion of Waning‐Stage Lava Lake Magmatic Foams and Anomalously Young Crater Retention Ages
Authors: Qiao Le , Head James W. , Ling Zongcheng , Wilson Lionel , Xiao Long , Dufek Josef D. , Yan Jianguo 
Published: March 2019

AbstractIna, a distinctive ~2 × 3 km D‐shaped depression, is composed of unusual bulbous‐shaped mounds surrounded by optically immature hummocky/blocky floor units. The crisp appearance, optical immaturity, and low number of superposed impact craters combine to strongly suggest a geologically recent formation for Ina, but the specific formation mechanism remains controversial. We reconfirm that Ina is a summit pit crater/vent on a small shield volcano ~3.5 billion years old. Following detailed characterization, we interpret the range of Ina characteristics to be consistent with a two‐component model of origin during the waning stages of summit pit eruption activities. The Ina pit crater floor is interpreted to be dominated by the products of late‐stage, low‐rise rate magmatic dike emplacement. Magma in the dike underwent significant shallow degassing and vesicle formation, followed by continued degassing below the solidified and highly microvesicular and macrovesicular lava lake crust, resulting in cracking of the crust and extrusion of gas‐rich magmatic foams onto the lava lake crust to form the mounds. These unique substrate characteristics (highly porous aerogel‐like foam mounds and floor terrains with large vesicles and void space) exert important effects on subsequent impact crater characteristics and populations, influencing (1) optical maturation processes, (2) regolith development, and (3) landscape evolution by modifying the nature and evolution of superposed impact craters and thus producing anomalously young crater retention ages. Accounting for these effects results in a shift of crater size‐frequency distribution model ages from <100 million years to ~3.5 billion years, contemporaneous with the underlying ancient shield volcano.
Modeling Climate Change Impacts on an Arctic Polygonal Tundra: 1. Rates of Permafrost Thaw Depend on Changes in Vegetation and Drainage
Authors: Grant R. F. , Mekonnen Z. A. , Riley W. J. 
Published: March 2019

AbstractModel projections of permafrost thaw during the next century diverge widely. Here we used ecosys to examine how climate change will affect permafrost thaw in a polygonal tundra at Barrow AK. The model was tested against diurnal and seasonal variation in energy exchange, soil heat flux, soil temperature (Ts), and active layer depth (ALD) measured during 2014 and 2015, and interannual variation in ALD measured from 1991 to 2015. During RCP 8.5 climate change from 2015 to 2085, increases in Ta and precipitation (P) to 6.2 °C and 27% above current values, and in atmospheric CO2 concentrations (Ca) to763 μmol mol−1, altered energy exchange by increasing leaf area index of dominant sedge relative to that of moss. Increased Ca and sedge leaf area index imposed greater stomatal control of transpiration and reduced soil heat fluxes, slowing soil warming, limiting increases in evapotranspiration, and thereby causing gradual soil wetting. Consequently, increases in surface Ts and ALD of 2.4–4.7 °C and 21–24 cm above current values were modeled after 70 years. ALD increase was slowed if model boundary conditions were altered to improve landscape drainage. These rates were smaller than those of earlier modeling studies, some of which did not account for changes in vegetation, but are closer to those derived from current studies of warming impacts in the region. Therefore, accounting for climate change effects on vegetation density and composition, and consequent effects on surface energy budgets, will cause slower increases in Ts and ALD to be modeled during climate change simulations.
Comparison analysis of low‐switching‐frequency‐based IPMSM sensorless drives considering regulators, observer and inverter non‐linearity
Authors: Zhang Hang , Liu Weiguo , Chen Zhe , Jiao Ningfei , Zhao Dongdong 
Published: March 2019

This study proposes an integration design of sensorless closed‐loop drives for rail transit application employing interior permanent magnet synchronous machine (IPMSM), which works under low switching frequency. Due to the long signal sampling period in high‐speed region, the individual back‐EMF observer cannot ensure the sensorless closed‐loop control stability. In order to increase the speed dynamic response and decouple the d–q axes currents accurately, a fast non‐singular terminal sliding mode control is designed. It combines a linear sliding mode factor with conventional non‐singular terminal sliding mode and is applied uniformly to position observer, speed and currents regulators. Then, considering the effect of inverter non‐linearity on position observer, the observed position error caused by dead‐time is analysed, and a compensation method based on q‐axis voltage error is proposed. Based on the above methods, a comparison analysis of position observer, speed and currents regulators is given. Finally, a 3.7 kW IPMSM is tested to verify the feasibility of the improved sensorless method.