bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance analysis of adaptive limited feedback coordinated zero‐forcing multicell systems in time‐varying channels: A practical approach
Authors: Balaji S. , Mallick P.S. 
Published: March 2017

SummaryIn this paper, coordinated limited feedback zero‐forcing beamforming multicell system in time‐varying channel is studied. In time‐varying channels, the actual rate loss arising from error in channel quantization of both interuser and intercell inferences is quantified in this work. Using the actual degradation of rate loss, a limited feedback bit allocation is proposed to reduce interuser and intercell interference simultaneously with feedback update period as one of the parameters. Furthermore, the scaling law of bits required to maintain a constant rate loss is formulated in varying channel conditions for a given feedback update period. Simulation results demonstrated the practical feedback requirement in multicell systems in the presence of both intercell and interuser interference over conventional schemes to maintain a constant rate offset. The key finding from the proposed feedback allocation is that practically much higher allocation of feedback bits and feedback scaling are required in time‐varying channels to reduce throughput degradation.
Ultrastructural alterations of pancreatic beta cells in human diabetes mellitus
Authors: Masini Matilde , Martino Luisa , Marselli Lorella , Bugliani Marco , Boggi Ugo , Filipponi Franco , Marchetti Piero , De Tata Vincenzo 
Published: March 2017

AbstractBackgroundBoth types of diabetes are characterized by beta‐cell failure and death, leading to insulin insufficiency. Very limited information is currently available about the ultrastructural alterations of beta cells in human diabetes. Our aim was to provide a comprehensive ultrastructural analysis of human pancreatic islets in type 1 (T1D) and type 2 (T2D) diabetic patients.MethodsWe performed a morphometric electron microscopy evaluation of beta cells obtained from the pancreas of 8 nondiabetic (ND), 5 T1D, and 8 T2D organ donors.ResultsA lower amount of beta cells was found in both T1D and T2D than in ND islets, whereas alpha cells were increased only in T2D. An increased number of bi‐hormonal cells (showing both insulin and glucagon granules in their cytoplasm) were found in T1D. Insulin granules were less represented in T2D than in ND beta cells, whereas no significant changes were found in T1D. Volume density of the endoplasmic reticulum was increased in T2D and unchanged in T1D; mitochondria number and volume were significantly higher in T2D than in ND beta cells, whereas no significant differences were found in T1D. In both T1D and T2D, more beta cells showed signs of apoptosis than in ND.ConclusionsOur results show that in each type of diabetes, beta cells exhibit specific ultrastructural alterations, whose better understanding might improve therapeutic strategies.
Plasma Sfrp5 levels correlate with determinants of the metabolic syndrome in Chinese adults
Authors: Xu Qiuyan , Wang Hongyan , Li Yang , Wang Jinzhi , Lai Yerui , Gao Lin , Lei Lu , Yang Gangyi , Liao Xin , Fang Xia , Liu Hua , Li Ling 
Published: March 2017

AbstractBackgroundSecreted frizzled‐related protein‐5 (Sfrp5) is a novel adipokine, and it has been found to link insulin resistance with diabetes. Animal studies have revealed the role of Sfrp5 in regulating lipid and glucose metabolism. The objective of this study was to investigate the relationship between Sfrp5 and the metabolic syndrome (MetS) in a cross‐sectional study.MethodsWe conducted a series of cross‐sectional studies of Chinese population including 194 control participants and 90 MetS patients. Circulating Sfrp5 concentrations were determined by ELISA. The relationships between circulating Sfrp5 levels and MetS components were assessed.ResultsCirculating Sfrp5 was significantly lower in newly examined MetS patients than in control participants (49.1 ± 17.2 vs 61.6 ± 23.2 μg/L, P < .01). Circulating Sfrp5 correlated negatively with markers of adiposity (waist‐to‐hip ratio, body mass index, and free fatty acids, P < .001 or P < .05). Furthermore, Sfrp5 levels correlated with fasting insulin, 2 h‐ins, fasting blood glucose, 2 h post‐glucose load blood glucose, HbA1c, and homeostasis model assessment of insulin resistance. In addition, circulating Sfrp5 levels were closely associated with blood pressure, high‐density lipoprotein cholesterol, triglycerides, and atherosclerotic index. Circulating concentrations of Sfrp5 decreased progressively with continued increases in the numbers of MetS components. The analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating Sfrp5 to predict MetS was 46.8 μg/L (sensitivity 70.1 %, specificity 47.8 %, and AUC 0.66).ConclusionsWe conclude that Sfrp5 may be an adipokine that is associated with the pathogenesis of MetS in humans.
Helophyte impacts on the response of hyporheic invertebrate communities to inundation events in intermittent streams
Authors: Baranov Viktor , Milošević Djuradj , Kurz Marie J. , Zarnetske Jay P. , Sabater Francesc , Marti Eugenia , Robertson Anne , Brandt Tanja , Sorolla Albert , Lewandowski Jörg , Krause Stefan 
Published: March 2017

AbstractThe effects of experimental inundation on invertebrate communities in artificial flumes fed with treated wastewater were investigated. Flumes, designed to simulate intermittent river conditions, were planted with 3 species of helophytes widely used in river restoration around the water‐stressed regions of Europe. Different species of vegetation had different capabilities to reduce the invertebrate's negative reaction to inundation, related mostly to rhizosphere density. Of the 3 helophyte species tested, only 1, Lysimachia vulgaris, showed significant capabilities to reduce invertebrate negative reaction on inundation. Species richness of invertebrates before and after the inundation did not change in any of the flumes, whereas species density significantly declined in all flumes except one planted with L. vulgaris. This helophyte species was associated with high densities of the Culicidae larvae (common mosquitos), which has severe implications for river restoration and vector management in the region. This study indicates that the selection and establishment of different helophyte species will impact invertebrate communities in restored streams, especially streams experiencing variable inundation conditions.
Groundcover community assembly in high‐diversity pine savannas: seed arrival and fire‐generated environmental filtering
Authors: Harms Kyle E. , Gagnon Paul R. , Passmore Heather A. , Myers Jonathan A. , Platt William J. 
Published: March 2017

AbstractEnvironmental filtering—abiotic and biotic constraints on the demographic performance of individual organisms—is a widespread mechanism of selection in communities. A given individual is “filtered out” (i.e., selectively removed) when environmental conditions or disturbances like fires preclude its survival and reproduction. Although interactions between these filters and dispersal from the regional species pool are thought to determine much about species composition locally, there have been relatively few studies of dispersal × filtering interactions in species‐rich communities and fewer still where fire is also a primary selective agent. We experimentally manipulated dispersal and filtering by fire (pre‐fire fuel loads and post‐fire ash) in species‐rich groundcover communities of the longleaf pine ecosystem. We tested four predictions: (1) That species richness would increase with biologically realistic dispersal (seed addition); (2) that the immediate effect of increased fuels in burned communities would be to decrease species richness, whereas the longer‐term effects of increased fuels would be to open recruitment opportunities in the groundcover, increase species richness, and increase individual performance (growth) of immigrating species; (3) that adding ash would increase species richness; and (4) that increased dispersal would generate larger increases in species richness in plots with increased fuels compared to plots with decreased fuels. We found that dispersal interacted with complex fire‐generated filtering during and after fires. Dispersal increased species richness more in burned communities with increased and decreased fuels compared to burned controls. Moreover, individuals of immigrating species generally grew to larger sizes in burned communities with increased fuels compared to burned controls. In contrast to dispersal and fuels, ash had no effect on species richness directly or in combination with other treatments. We conclude that filtering occurs both during fires and in the post‐fire environment and that these influences interact with dispersal such that the consequences are only fully revealed when all are considered in combination. Our experiment highlights the importance of considering the dynamic interplay of dispersal and selection in the assembly of species‐rich communities.
Effects of experimentally reduced snowpack and passive warming on montane meadow plant phenology and floral resources
Authors: Sherwood J. A. , Debinski D. M. , Caragea P. C. , Germino M. J. 
Published: March 2017

AbstractClimate change can have a broad range of effects on ecosystems and organisms, and early responses may include shifts in vegetation phenology and productivity that may not coincide with the energetics and forage timing of higher trophic levels. We evaluated phenology, annual height growth, and foliar frost responses of forbs to a factorial experiment of snow removal (SR) and warming in a high‐elevation meadow over two years in the Rocky Mountains, United States. Species included arrowleaf balsamroot (Balsamorhiza sagittata, early‐season emergence and flowering) and buckwheat (Eriogonum umbellatum, semi‐woody and late‐season flowering), key forbs for pollinator and nectar‐using animal communities that are widely distributed and locally abundant in western North America. Snow removal exerted stronger effects than did warming, and advanced phenology differently for each species. Specifically, SR advanced green‐up by a few days for B. sagittata to >2 wk in E. umbellatum, and led to 5‐ to 11‐d advances in flowering of B. sagittata in one year and advances in bud break in 3 of 4 species/yr combinations. Snow removal increased height of E. umbellatum appreciably (~5 cm added to ~22.8 cm in control), but led to substantial increases in frost damage to flowers of B. sagittata. Whereas warming had no effects on E. umbellatum, it increased heights of B. sagittata by >6 cm (compared to 30.7 cm in control plots) and moreover led to appreciable reductions in frost damage to flowers. These data suggest that timing of snowmelt, which is highly variable from year to year but is advancing in recent decades, has a greater impact on these critical phenological, growth, and floral survival traits and floral/nectar resources than warming per se, although warming mitigated early effects of SR on frost kill of flowers. Given the short growing season of these species, the shifts could cause uncoupling in nectar availability and timing of foraging.
Capillary‐assisted bipolar electrochemistry: A focused mini review
Authors: Bouffier Laurent , Sojic Neso , Kuhn Alexander 
Published: March 2017

AbstractA bipolar electrode is quite unconventional as it behaves simultaneously as an anode and a cathode in contrast to a classic electrochemical setup where the electron transfer reactions are promoted on two different electrodes. The driving force is the polarization potential established between the solution and the bipolar electrode, that allows a wireless electrochemical addressing. In the past decade or so, bipolar electrochemistry has encountered a remarkable renewal of interest with extraordinary potentialities ranging from materials science to analytical chemistry. For practical reasons, bipolar electrochemistry experiments are very often performed in handmade electrochemical cells comprising tubes or capillaries. This review is focused on specific applications based on such types of experimental setups, from the macroscale where the tube acts only as an ordinary container down to the microscale where specific properties of the capillary come also into play.
Fast pyrolysis of coffee ground in a tilted‐slide reactor and characteristics of biocrude oil
Authors: Choi Yeon Seok , Choi Sang Kyu , Kim Seock Joon , Jeong Yeon Woo , Soysa Ramesh , Rahman Tawsif 
Published: March 2017

Coffee grounds are considered to be a promising biomass resource due to the growth of coffee consumption and their high calorific value. In this study, we produced biocrude oil from coffee grounds in a tilted‐slide reactor, which has been previously used for the fast pyrolysis of woody biomass. Various pyrolysis temperatures were tested and the maximum biocrude oil yield was 59% at the pyrolysis temperature of 550°C with a feeding rate of coffee grounds at 17.7 kg/h. In a multistage condenser, the biocrude oil yields and properties were different in each condenser stage. The higher heating value of the biocrude oil from the primary condenser was 7,157 kcal/kg, which was about 60% higher than that from woody biomass. A phase separation was observed when the biocrude oil was stored at the atmospheric condition, and the biocrude oil viscosity became quite larger than that from woody biomass, which could even impede its flow. The viscosity decreased with increasing temperature and was more sensitive to temperature variations at lower temperatures. Mixing of ethanol also significantly improved viscosity characteristics. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 655–661, 2017
Improving bank erosion modelling at catchment scale by incorporating temporal and spatial variability
Authors: Janes Victoria , Holman Ian , Birkinshaw Stephen , O'Donnell Greg , Kilsby Chris 
Published: March 2017

AbstractBank erosion can contribute a significant portion of the sediment budget within temperate catchments, yet few catchment scale models include an explicit representation of bank erosion processes. Furthermore, representation is often simplistic resulting in an inability to capture realistic spatial and temporal variability in simulated bank erosion. In this study, the sediment component of the catchment scale model SHETRAN is developed to incorporate key factors influencing the spatio‐temporal rate of bank erosion, due to the effects of channel sinuosity and channel bank vegetation. The model is applied to the Eden catchment, north‐west England, and validated using data derived from a GIS methodology. The developed model simulates magnitudes of total catchment annual bank erosion (617–4063 t y‐1) within the range of observed values (211–4426 t yr‐1). In addition, the model provides both greater inter‐annual and spatial variability of bank eroded sediment generation when compared with the basic model, and indicates a potential 61% increase of bank eroded sediment as a result of temporal flood clustering. The approach developed within this study can be used within a number of distributed hydrologic models and has general applicability to temperate catchments, yet further development of model representation of bank erosion processes is required. © 2017 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.
Partitioning of nanoparticle-originated dissolved silver in natural and artificial sediments
Authors: Rajala Juho E. , Vehniäinen Eeva-Riikka , Väisänen Ari , Kukkonen Jussi V.K. 
Published: March 2017

Abstract

Sediments are believed to be a major sink for silver nanoparticles (AgNPs) in the aquatic environment, but there is a lack of knowledge about the environmental effects and behavior of AgNPs in sediments. The release of highly toxic Ag+ through dissolution of AgNPs is one mechanism leading to toxic effects in sediments. We applied an ultrasound-assisted sequential extraction method to evaluate the dissolution of AgNPs and to study the partitioning of dissolved Ag in sediments. Silver was spiked into artificial and 2 natural sediments (Lake Höytiäinen sediment and Lake Kuorinka sediment) as silver nitrate (AgNO3), uncoated AgNPs, or polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). In addition, the total body burdens of Ag in the sediment-dwelling oligochaete Lumbriculus variegatus were assessed over a 28-d exposure period. The dissolution rate was found to be similar between the uncoated AgNP and PVP-AgNP groups. In all sediments, dissolved Ag was mainly bound to the residual fraction of the sediment, followed by iron and manganese oxides or natural organic matter. In Lake Kuorinka sediment, dissolved Ag that originated from PVP-AgNPs was relatively more bioaccessible, also resulting in higher total body burden in L. variegatus than that from uncoated AgNPs or AgNO3. In artificial sediment and Lake Höytiäinen sediment, AgNO3 was significantly more bioaccessible than AgNPs. Our results highlight the importance of sediment properties and AgNP surface chemistry when evaluating the environmental exposure of AgNPs. Environ Toxicol Chem 2017;36:2593–2601. © 2017 SETAC
Overlay spectrum sharing for device‐to‐device communications in two‐way cellular networks with nodes mobility
Authors: Gurjar Devendra Singh , Upadhyay Prabhat Kumar 
Published: March 2017

AbstractIn this paper, we propose and investigate a three‐phase overlay spectrum‐sharing scheme for device‐to‐device (D2D) communications in a bidirectional cellular network with nodes mobility. In this scheme, a pair of D2D users facilitates relaying to the cellular nodes (base station and mobile user), and in return, they get the opportunity to exchange their own information by exploiting the same cellular spectrum. With this, the two end‐to‐end bidirectional communications (D2D and cellular) can be realized in three time phases by using selection‐combining technique at both cellular nodes and decode‐and‐forward (DF) relaying scheme at both participating D2D users. For DF operation, we consider two strategies, namely, exclusive‐OR (XOR)‐based DF, and superposition‐based DF. All the channels are assumed to be time varying, and Markovian model is used to characterize the impact of nodes mobility. For this set‐up, we first derive the outage probability for both cellular and D2D links under Rayleigh fading. Then, we obtain the asymptotic expressions of outage probability for both systems and used them further to reveal the critical value of power‐splitting factor for spectrum sharing. Above all, we acquire the expression of average system throughput to perform a fair performance comparison with the other existing schemes.
Delay analysis of mixed fronthaul and backhaul traffic under strict priority queueing discipline in a 5G packet transport network
Authors: Gowda Apurva , Hernández José Alberto , Larrabeiti David , Kazovsky Leonid 
Published: March 2017

AbstractVirtualization of the base station for the purpose of centralization is being actively studied and researched as an implementation option for 5G mobile networks. Proposed as Cloud radio access network, the technology is expected to facilitate easier operation and maintenance than regular radio access networks. However, the base stations traffic has stringent delay requirements. In this paper, we explore the possibility of multiplexing fronthaul traffic and traditional backhaul traffic as it traverses over the metropolitan network while keeping the average fronthaul queueing delay and jitter under control. We analyze and simulate the cases of a single fronthaul flow and multiple fronthaul flows arriving at the packet switch assuming strict priority for the fronthaul queue. We propose a fronthaul frame aggregation strategy to improve the packet transmission efficiency while keeping the average fronthaul queueing delay and jitter constant regardless of the percentage of fronthaul traffic. While the criteria for aggregation is different for the 2 cases, we show that the optimal number of basic frames to aggregate is between 3‐10 frames assuming the Common Public Radio Interface protocol.
The percutaneous toxicokinetics of Sulphur mustard in a damaged skin porcine model and the evaluation of WoundStat™ as a topical decontaminant
Authors: Hall Charlotte A. , Lydon Helen L. , Dalton Christopher H. , Chipman J. Kevin , Graham John S. , Chilcott Robert P. 
Published: March 2017

AbstractThis study used a damaged skin, porcine model to evaluate the in vivo efficacy of WoundStat™ for decontamination of superficial (non‐haemorrhaging), sulphur mustard‐contaminated wounds. The dorsal skin of 12 female pigs was subjected to controlled physical damage and exposed to 10 μL 14C–radiolabelled sulphur mustard (14C–SM). Animals were randomly assigned to either a control or a treatment group. In the latter, WoundStat™ was applied 30 s post exposure and left in situ for 1 h. Skin lesion progression and decontaminant efficacy were quantified over 6 h using a range of biophysical measurements. Skin, blood and organ samples were taken post mortem for histopathological assessment, 14C–SM distribution and toxicokinetic analyses. Application of SM to damaged skin without decontamination was rapidly followed by advanced signs of toxicity, including ulceration and decreased blood flow at the exposure site in all animals. WoundStat™ prevented ulceration and improved blood flow at the exposure site in all decontaminated animals (n = 6). Furthermore, significantly smaller quantities of 14C–SM were detected in the blood (45% reduction), and recovered from skin (70% reduction) and skin surface swabs (99% reduction) at 6 h post‐challenge. Overall, the distribution of 14C–SM in the internal organs was similar for both groups, with the greatest concentration in the kidneys, followed by the liver and small intestine. WoundStat™ significantly reduced the amount of 14C–SM recovered from the liver, a key organ for SM metabolism and detoxification. This study demonstrates that WoundStat™ is a suitable product for reducing the ingress and toxicity of a chemical warfare agent. Copyright © 2017 John Wiley & Sons, Ltd.
Natural polymeric hydrogel evaluation for skeletal muscle tissue engineering
Authors: Pollot Beth E. , Rathbone Christopher R. , Wenke Joseph C. , Guda Teja 
Published: March 2017

AbstractAlthough skeletal muscle has a remarkable ability to repair/regenerate after most types of injuries, there is limited regeneration after volumetric muscle loss (VML). A number of scaffold materials have been used in the development of grafts to treat VML, however, there is still a need to better understand the most appropriate material with regards to its ability to maintain mechanical integrity while also supporting myogenesis. Five commonly used natural polymeric materials (Collagen I, Agarose, Alginate, Fibrin, and Collagen Chitosan) used in skeletal muscle tissue engineering grafts were evaluated for their mechanical properties and myogenic capacity. Rheological properties, water absorption rates, degradation stability, tensile characteristics, and the ability to support in vitro myogenesis were compared in all five materials. Collagen, Collagen Chitosan, and Fibrin demonstrated high elasticity and 100% stretch without failure, Agarose was the most brittle (20% max stretch), and Alginate demonstrated poor handleabilty. While Collagen was supportive of myogenesis, overall, Fibrin demonstrated the highest myogenic potential as indicated by the earliest and highest increases in myogenin and myosin heavy chain mRNA in satellite cells along with the most extensive myotube development as evaluated with immunohistochemistry. The findings herein support the notion that under the conditions used in this study, Fibrin is the most suitable scaffold for the development of scaffolds for skeletal muscle tissue engineering. Future studies are required to determine whether the differences in mechanical properties and myogenic potential observed in vitro in the current study translate to better skeletal muscle development in a VML injury model. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 672–679, 2018.