bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using the Lewis Acid Me3Si−F−Al(ORF)3 To Prepare Phosphino‐Phosphonium Cations with the Least‐Coordinating Anion [(RFO)3Al−F−Al(ORF)3]−
Authors: Possart Josephine , Martens Arthur , Schleep Mario , Ripp Alexander , Scherer Harald , Kratzert Daniel , Krossing Ingo 
Published: May 2017

AbstractBy reaction of two equivalents of Me3Si−F−Al(ORF)3 1 with an equimolar amount of PPh2Cl, the salt [Ph2P−PPh2Cl]+[(RFO)3Al−F−Al(ORF)3]− 2 is prepared smoothly in 91 % yield (NMR, XRD). The synthesis of [Ph2P−PPh3]+[(RFO)3Al−F−Al(ORF)3]− 3 is best achieved by a two‐step reaction: first, two equivalents of 1 react with one PPh3 to give [Me3Si−PPh3]+[(RFO)3Al−F−Al(ORF)3]− 4 (NMR, XRD), which, upon reaction with PPh2Cl, yields pure 3 and Me3SiCl (NMR, XRD). Typically, a stoichiometry of two equivalents of 1 with respect to one equivalent of the chloride donor should be used. Otherwise, the residual strong Lewis acidity of the [(RFO)3Al−F−Al(ORF)3]− anion in the presence of the [F−Al(ORF)3]− anion—that forms with less than two equivalents of 1—leads to further chloride exchange reactions that complicate work‐up. This route presents the easiest way to introduce the least‐coordinating [(RFO)3Al−F−Al(ORF)3]− anion into a system. We expect a wide use of this route in all areas, in which chloride‐bond heterolysis in combination with very weakly coordinating anions is desirable. Additionally, we performed calculations on the bond dissociation mechanisms of [R2P−PMe3]+ and the isoelectronic Me2P−SiMe3 and Me2Si−PMe3 in dependence of the solvent permittivity. These calculations show, especially for the neutral reference compounds, a heavy influence of the solvent on the dissociation mechanism, which is why we suggest investigating these properties in solution instead of gas phase.
Influence of the Substrate/Inoculum Ratio on Process Stability and Performance during Batch Digestion of Grass Silage
Authors: Benito Patricia C. , Greger Manfred 
Published: May 2017

AbstractThe impact of the substrate/inoculum ratio on the performance and process stability during batch digestion of grass silage, an important substrate in biogas plants, was investigated. The methane yield, degradability, and evolution of intermediary products were monitored in mesophilic reactors fed with increasing amounts of grass silage. A first‐order kinetics model was also applied. Signs of inhibition were observed for the highest loadings, but the system recovered and process failure was not observed. The methane yield decreased with increasing loading but the system was resilient to high loadings under batch conditions.
Facile Synthesis of Nitrogen‐Doped Graphene Aerogels for Electrode Materials in Supercapacitors
Authors: Zhang Yong , Zhu Jiayi , Ren Hongbo , Bi Yutie , Zhang Lin 
Published: May 2017

AbstractThree‐dimensional porous nitrogen‐doped graphene aerogels (NGAs) were synthesized by using graphene oxide (GO) and chitosan (CS) via a self‐assembly process by one‐pot hydrothermal method. The morphology and structure of the as‐prepared materials were characterized by means of scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, XPS spectroscopy, Raman spectroscopy, nitrogen adsorption/desorption measurement and Fourier transform infrared spectroscopy. The electrochemical performance of NGAs was studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The microstructure, surface area and capacitance of NGAs could be facilely controlled by adding different amounts of chitosan. The prepared NGA‐4 showed a specific capacitance of 148.0 F/g at the discharge current density of 0.5 A/g and also retained 95.3% of the initial capacitance after 5000 cycles at the scan rate of 10 mV/s. It provided a possible way to obtain graphene based materials with high surface area and capacitance.
A LoCATe‐based visual place recognition system for mobile robotics and GPGPUs
Authors: Bampis Loukas , Chatzichristofis Savvas , Iakovidou Chryssanthi , Amanatiadis Angelos , Boutalis Yiannis , Gasteratos Antonios 
Published: May 2017

SummaryIn this paper, a novel visual Place Recognition approach is evaluated based on a visual vocabulary of the Color and Edge Directivity Descriptor (CEDD) to address the loop closure detection task. Even though CEDD was initially designed so as to globally describe the color and texture information of an input image addressing Image Indexing and Retrieval tasks, its scalability on characterizing single feature points has already been proven. Thus, instead of using CEDD as a global descriptor, we adopt a bottom‐up approach and use its localized version, Local Color And Texture dEscriptor, as an input to a state‐of‐the‐art visual Place Recognition technique based on Visual Word Vectors. Also, we use a parallel execution pipeline based on a previous work of ours using the well established General Purpose Graphics Processing Unit (GPGPU) computing. Our experiments show that the usage of CEDD as a local descriptor produces high accuracy visual Place Recognition results, while the parallelization used allows for a real‐time implementation even in the case of a low‐cost mobile device.
Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling
Authors: Wang Weizong , Patil Bhaskar , Heijkers Stjin , Hessel Volker , Bogaerts Annemie 
Published: May 2017

AbstractInvited for this month's cover is the group of Prof. Dr. Annemie Bogaerts at the University of Antwerp and their collaborators at Eindhoven University of Technology in the laboratory of Prof. Dr. Volker Hessel. The cover image shows that gliding arc plasma leads to energy efficient nitrogen fixation by promoting the vibrational excitation of N2. The Full Paper itself is available at 10.1002/cssc.201700095.
New insights into the genetic composition and phylogenetic relationship of wolves and dogs in the Iberian Peninsula
Authors: Pires Ana Elisabete , Amorim Isabel R. , Borges Carla , Simões Fernanda , Teixeira Tatiana , Quaresma Andreia , Petrucci‐Fonseca Francisco , Matos José 
Published: May 2017

AbstractThis study investigates the gene pool of Portuguese autochthonous dog breeds and their wild counterpart, the Iberian wolf subspecies (Canis lupus signatus), using standard molecular markers. A combination of paternal and maternal molecular markers was used to investigate the genetic composition, genetic differentiation and genetic relationship of native Portuguese dogs and the Iberian wolf. A total of 196 unrelated dogs, including breed and village dogs from Portugal, and other dogs from Spain and North Africa, and 56 Iberian wolves (wild and captive) were analyzed for nuclear markers, namely Y chromosome SNPs, Y chromosome STR loci, autosomal STR loci, and a mitochondrial fragment of the control region I. Our data reveal new variants for the molecular markers and confirm significant genetic differentiation between Iberian wolf and native domestic dogs from Portugal. Based on our sampling, no signs of recent introgression between the two subspecies were detected. Y chromosome data do not reveal genetic differentiation among the analyzed dog breeds, suggesting they share the same patrilineal origin. Moreover, the genetic distinctiveness of the Iberian wolf from other wolf populations is further confirmed with the description of new mtDNA variants for this endemism. Our research also discloses new molecular markers for wolf and dog subspecies assignment, which might become particularly relevant in the case of forensic or noninvasive genetic studies. The Iberian wolf represents a relic of the once widespread wolf population in Europe and our study reveals that it is a reservoir of unique genetic diversity of the grey wolf, Canis lupus. These results stress the need for conservation plans that will guarantee the sustainability of this threatened top predator in Iberia.
Tracking a single pigeon using a shadowing filter algorithm
Authors: Zaitouny Ayham , Stemler Thomas , Small Michael 
Published: May 2017

AbstractMiniature GPS devices now allow for measurement of the movement of animals in real time and provide high‐ quality and high‐resolution data. While these new data sets are a great improvement, one still encounters some measurement errors as well as device failures. Moreover, these devices only measure position and require further reconstruction techniques to extract the full dynamical state space with the velocity and acceleration. Direct differentiation of position is generally not adequate. We report on the successful implementation of a shadowing filter algorithm that (1) minimizes measurement errors and (2) reconstructs at the same time the full phase‐space from a position recording of a flying pigeon. This filter is based on a very simple assumption that the pigeon's dynamics are Newtonian. We explore not only how to choose the filter's parameters but also demonstrate its improvements over other techniques and give minimum data requirements. In contrast to competing filters, the shadowing filter's approach has not been widely implemented for practical problems. This article addresses these practicalities and provides a prototype for such application.
Couch potatoes do better: Delayed dispersal and territory size affect the duration of territory occupancy in a monogamous mammal
Authors: Mayer Martin , Zedrosser Andreas , Rosell Frank 
Published: May 2017

AbstractIn territorial, socially monogamous species, the establishment and defense of a territory are an important strategy to maximize individual fitness, but the factors responsible for the duration of territory occupancy are rarely studied, especially in long‐lived mammals. A long‐term monitoring program in southeast Norway spanning over 18 years allowed us to follow the individual life histories of Eurasian beavers (Castor fiber) from adolescence in their natal family group to dispersal and territory establishment until the end of territory occupancy. We investigated whether territory size, resource availability, population density, and dispersal age could explain the duration of territory occupancy, which ranged from 1 to 11 years. The duration of territory occupancy was positively related to dispersal age, suggesting that individuals that delayed dispersal had a competitive advantage due to a larger body mass. This is in support with the maturation hypothesis, which states that an animal should await its physical and behavioral maturation before the acquisition of a territory. Further, we found that individuals that established in medium‐sized territories occupied them longer as compared to individuals in small or large territories. This suggests that large territories are more costly to defend due to an increased patrolling effort, and small territories might not have sufficient resources. The lifetime reproductive success ranged from zero to six kits and generally increased with an increasing duration of territory occupancy. Our findings show the importance of holding a territory and demonstrate that dispersal decisions and territory selection have important consequences for the fitness of an individual.
Global realized niche divergence in the African clawed frog Xenopus laevis
Authors: Rödder Dennis , Ihlow Flora , Courant Julien , Secondi Jean , Herrel Anthony , Rebelo Rui , Measey G. J. , Lillo Francesco , De Villiers F. A. , De Busschere Charlotte , Backeljau Thierry 
Published: May 2017

AbstractAlthough of crucial importance for invasion biology and impact assessments of climate change, it remains widely unknown how species cope with and adapt to environmental conditions beyond their currently realized climatic niches (i.e., those climatic conditions existing populations are exposed to). The African clawed frog Xenopus laevis, native to southern Africa, has established numerous invasive populations on multiple continents making it a pertinent model organism to study environmental niche dynamics. In this study, we assess whether the realized niches of the invasive populations in Europe, South, and North America represent subsets of the species’ realized niche in its native distributional range or if niche shifts are traceable. If shifts are traceable, we ask whether the realized niches of invasive populations still contain signatures of the niche of source populations what could indicate local adaptations. Univariate comparisons among bioclimatic conditions at native and invaded ranges revealed the invasive populations to be nested within the variable range of the native population. However, at the same time, invasive populations are well differentiated in multidimensional niche space as quantified via n‐dimensional hypervolumes. The most deviant invasive population are those from Europe. Our results suggest varying degrees of realized niche shifts, which are mainly driven by temperature related variables. The crosswise projection of the hypervolumes that were trained in invaded ranges revealed the south‐western Cape region as likely area of origin for all invasive populations, which is largely congruent with DNA sequence data and suggests a gradual exploration of novel climate space in invasive populations.
Driving factors and temporal fluctuation of Collembola communities and reproductive mode across forest types and regions
Authors: Pollierer Melanie M. , Scheu Stefan 
Published: May 2017

AbstractDespite the major role of Collembola in forest soil animal food webs, ecological and evolutionary determinants of their community composition are not well understood. We investigated abundance, community structure, life forms, and reproductive mode of Collembola in four different forest types (coniferous, young managed beech, old managed beech, and unmanaged beech forests) representing different management intensities. Forest types were replicated within three regions across Germany: the Schorfheide‐Chorin, the Hainich, and the Swabian Alb, differing in geology, altitude, and climate. To account for temporal variation, samples were taken twice with an interval of 3 years. To identify driving factors of Collembola community structure, we applied structural equation modeling, including an index of forest management intensity, abiotic and biotic factors such aspH, C‐to‐N ratio of leaf litter, microbial biomass, and fungal‐to‐bacterial ratio. Collembola abundance, biomass, and community composition differed markedly between years, with most pronounced differences in the Schorfheide, the region with the harshest climatic conditions. There, temporal fluctuations of parthenogenetic Collembola were significantly higher than in the other regions. In the year with the more favorable conditions, parthenogenetic species flourished, with their abundance depending mainly on abiotic, density‐independent factors. This is in line with the “Structured Resource Theory of Sexual Reproduction,” stating that parthenogenetic species are favored if density‐independent factors, such as desiccation, frost or flooding, prevail. In contrast, sexual species in the same year were mainly influenced by resource quality‐related factors such as the fungal‐to‐bacterial ratio and the C‐to‐N ratio of leaf litter. The influence of forest management intensity on abundances was low, indicating that disturbance through forest management plays a minor role. Accordingly, differences in community composition were more pronounced between regions than between different forest types, pointing to the importance of regional factors.
Monitoring for Adaptive Management or Modernity: Lessons from recent initiatives for holistic environmental management
Authors: Waylen Kerry A. , Blackstock Kirsty L. 
Published: May 2017

AbstractRecommendations for improving environmental management often advocate a holistic approach that supports both social and environmental objectives. This should be reflected in approaches to monitoring and evaluation; however, monitoring is often inadequate and hence limits our ability to implement adaptive management. It is important to understand if monitoring practices are changing, and if not, why. Thus, this paper considers the monitoring practices and priorities of 24 ‘Ecosystem Approach’ projects implementing holistic and participatory environmental management. We found project monitoring was often focused on biophysical indicators, such as indicators of water pollution, even when adaptive management might prioritize understanding different issues or using different data‐types. By contrast, aspects of social and economic aspects were monitored infrequently. Procedural aspects were rarely tracked. Project managers' aspirations did sometimes include such issues, but these were seen as more difficult or even impossible to measure. Schema were also shaped by the need to demonstrate accountability and quantify progress to funders. Our study suggests monitoring still falls short of theoretical recommendations. This is partially due to the misfit between new understandings of socio‐ecological systems and pre‐existing modernist paradigms, whose conceptions and expectations still have pervasive effects of our ways of thinking and working. Tackling this requires explicit attention to sticking points across the levels of institutions that shape environmental management. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Direct estimation of the spontaneous mutation rate by short-term mutation accumulation lines inChironomus riparius
Authors: Oppold Ann-Marie , Pfenninger Markus 
Published: May 2017

AbstractMutations are the ultimate basis of evolution, yet their occurrence rate is known only for few species. We directly estimated the spontaneous mutation rate and the mutational spectrum in the nonbiting midge C. riparius with a new approach. Individuals from ten mutation accumulation lines over five generations were deep genome sequenced to count de novo mutations that were not present in a pool of F1 individuals, representing parental genotypes. We identified 51 new single site mutations of which 25 were insertions or deletions and 26 single nucleotide mutations. This shift in the mutational spectrum compared to other organisms was explained by the high A/T content of the species. We estimated a haploid mutation rate of 2.1 × 10−9 (95% confidence interval: 1.4 × 10−9 – 3.1 × 10-9) that is in the range of recent estimates for other insects and supports the drift barrier hypothesis. We show that accurate mutation rate estimation from a high number of observed mutations is feasible with moderate effort even for nonmodel species.
Nanoporous UHMWPE Membrane Separators for Safer and High‐Power‐Density Rechargeable Batteries
Authors: Li Runlai , Gao Ping 
Published: May 2017

Battery safety has been of critical concerns and there are renewed interest in developing safer membranes for enhancing the inherent safety of lithium ion batteries. In this paper, the synthesis of a robust and safer self‐reinforced composite ultrahigh molecular weight polyethylene (UHMWPE) membrane is described. The self‐reinforced composite membrane consists of ≈200 nm nanopores homogeneously embedded inside interpenetrating nanofibrillar “shish kebab” networks. It performs thermal fuse function by selectively melting its kebab crystals while the elongated shish fibrillary backbones remain intact. Simulated thermal fuse function tests show that the newly prepared separator displays a 300% increase in tensile strength (550 MPa), 300% increase in puncture resistance (1.5 N μm−1), as well as an 18 000 times increase in impedance when lateral dimensions are kept constant. Cells prepared using the UHMWPE separators also exhibit a 10% higher energy density and better cyclability than those using commercial separators. Hence, the newly prepared ultrathin and dimensionally stable membrane will enhance the safety protections for rechargeable batteries with low impedance for high energy and power density.
Optical coherence elastography for strain dynamics measurements in laser correction of cornea shape
Authors: Zaitsev Vladimir Y. , Matveyev Alexander L. , Matveev Lev A. , Gelikonov Grigory V. , Omelchenko Alexander I. , Baum Olga I. , Avetisov Sergey E. , Bolshunov Andrey V. , Siplivy Vladimir I. , Shabanov Dmitry V. , Vitkin Alex , Sobol Emil N. 
Published: May 2017

AbstractWe describe the use of elastographic processing in phase‐sensitive optical coherence tomography (OCT) for visualizing dynamics of strain and tissue‐shape changes during laser‐induced photothermal corneal reshaping, for applications in the emerging field of non‐destructive and non‐ablative (non‐LASIK) laser vision correction. The proposed phase‐processing approach based on fairly sparse data acquisition enabled rapid data processing and near‐real‐time visualization of dynamic strains. The approach avoids conventional phase unwrapping, yet allows for mapping strains even for significantly supra‐wavelength inter‐frame displacements of scatterers accompanied by multiple phase‐wrapping. These developments bode well for real‐time feedback systems for controlling the dynamics of corneal deformation with 10–100 ms temporal resolution, and for suitably long‐term monitoring of resultant reshaping of the cornea. In ex‐vivo experiments with excised rabbit eyes, we demonstrate temporal plastification of cornea that allows shape changes relevant for vision‐correction applications without affecting its transparency. We demonstrate OCT's ability to detect achieving of threshold temperatures required for tissue plastification and simultaneously characterize transient and cumulative strain distributions, surface displacements, and scattering tissue properties. Comparison with previously used methods for studying laser‐induced reshaping of cartilaginous tissues and numerical simulations is performed.
Bone Loss at the Hip and Subsequent Mortality in Older Men: The Osteoporotic Fractures in Men (MrOS) Study
Authors: Cawthon Peggy M , Patel Sheena , Ewing Susan K , Lui Li‐Yung , Cauley Jane A , Lyons Jennifer G , Fredman Lisa , Kado Deborah M , Hoffman Andrew R , Lane Nancy E , Ensrud Kristine E , Cummings Steven R , Orwoll Eric S ,   for the Osteoporotic Fractures in Men (MrOS) Study Research Group
Published: May 2017

AbstractLow bone mineral density (BMD) is associated with increased mortality risk, yet the impact of BMD loss on mortality is relatively unknown. We hypothesized that greater BMD loss is associated with increased mortality risk in older men. Change in femoral neck BMD was assessed in 4400 Osteoporotic Fractures in Men (MrOS) study participants with two to three repeat dual‐energy X‐ray absorptiometry scans over an average of 4.6 ± 0.4 (mean ± SD) years. Change in femoral neck BMD was estimated using mixed effects models; men were grouped into three categories of BMD change: maintenance (n = 1087; change ≥ 0 g/cm2); expected loss (n = 2768; change between 0 g/cm2 and <1 SD below mean change [>–0.034 g/cm2]); and accelerated loss (n = 545; change 1 SD below mean change or worse [≤–0.034 g/cm2]). Multivariate proportional hazards models adjusted for potential confounders estimated the risk of all‐cause mortality over 8.1 ± 2.8 years following visit 2. Mortality was centrally adjudicated by physician review of death certificates. At visit 1, mean age was 72.9 ± 5.5 years. Men who maintained BMD were less likely to die during the subsequent follow‐up period (33.7%) than men who had accelerated BMD loss (60.6%) (p < 0.001). Compared to men who had maintained BMD, those who had accelerated BMD loss had a 44% greater risk of mortality in multivariate‐adjusted models (HR, 1.44; 95% CI, 1.23 to 1.68). Compared to men who had maintained BMD, there was no significant difference in mortality risk for men with expected loss of BMD (36.9% died) (multivariate HR, 1.00; 95% CI, 0.89 to 1.13). Further adjustment for visit 1 or visit 2 BMD measurement did not substantially alter these associations. Results for total hip BMD were similar. In conclusion, accelerated loss of BMD at the hip is a risk factor for mortality in men that is not explained by comorbidity burden, concurrent change in weight, or physical activity. © 2017 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.