bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Organic Additives on the Activity and Selectivity of CO2 Electroreduction: The Role of Functional Groups
Authors: Xu Wenbin , Qiu Yanling , Zhang Taotao , Li Xianfeng , Zhang Huamin 
Published: July 2018

AbstractElectrochemical reduction of CO2 (ERC) to useful chemicals is an environmentally and technologically significant process. The process is confronted with significant challenges to simultaneously enhance the catalyst activity and product selectivity. In this paper, the effects of organic additives on the ERC process were systematically investigated by using DFT to screen additives with different functional groups for enhanced activity and selectivity. In particular, the additives with −NH3+ and −SO3H groups had a remarkably positive effect on the ERC activity and hydrocarbon selectivity, which were predicted to impart a positive shift on onset potential of approximately 162 and 108 mV, respectively. Importantly, the additive can accelerate the electron transfer of the intermediate and tune the electronic structure of the catalyst surface, resulting in a clear deviation from transition‐metal scaling lines. Combining bonding energy of crucial intermediates with partial atomic charge analysis, we rationalized the negative effect of high concentration additives and confirmed the proposed electron transfer model. Furthermore, additive molecules containing functional groups with positive charges and maximizing the deviation from transition‐metal scaling lines are meaningful strategies to design and choose organic additives to enhance activity and selectivity of ERC.
Assessing the role of ontogenetic movement in maintaining population structure in fish using otolith microchemistry
Authors: Wright Peter J. , Régnier Thomas , Gibb Fiona M. , Augley Julian , Devalla Sandhya 
Published: July 2018

AbstractIdentifying the mechanisms maintaining population structure in marine fish species with more than a single dispersing life stage is challenging because of the difficulty in tracking all life stages. Here, a two‐stage otolith microchemistry approach to examining life‐stage movement was adopted, tracking a year‐class from the juvenile to adult stage and inferring larval sources from clustering, in order to consider the mechanisms maintaining population structuring in North Sea cod. Clustering of near‐core chemistry identified four clusters, two of which had either a southern or northern affinity and were similar to juvenile edge chemistry. The other two clusters, common to the central North Sea, had intermediate chemical composition and may have reflected either larval mixing in this region or a lack of geographic heterogeneity in the elemental signature. From the comparison of whole juvenile and the corresponding component of adult otoliths, adults from the southern North Sea mostly recruited from adjacent nursery grounds. In contrast, many adults in the northern North Sea had a juvenile chemistry consistent with the Skagerrak and juveniles from the northern Skagerrak site had a near‐core chemistry consistent with the northern North Sea. Similarities in otolith chemistry were consistent with retention of early life stages at a regional level and also juvenile and adult fidelity. The links between the northern North Sea and Skagerrak indicate natal homing, which when considered in the context of genetic evidence is suggestive of philopatry. The approach used here should be useful in exploring the mechanisms underlying population structuring in other species with multiple dispersive life stages and calcified hard parts.
Local trampling disturbance effects on alpine plant populations and communities: Negative implications for climate change vulnerability
Authors: Chardon Nathalie Isabelle , Wipf Sonja , Rixen Christian , Beilstein Annabarbara , Doak Daniel Forest 
Published: July 2018

AbstractGlobal change is modifying species communities from local to landscape scales, with alterations in the abiotic and biotic determinants of geographic range limits causing species range shifts along both latitudinal and elevational gradients. An important but often overlooked component of global change is the effect of anthropogenic disturbance, and how it interacts with the effects of climate to affect both species and communities, as well as interspecies interactions, such as facilitation and competition. We examined the effects of frequent human trampling disturbances on alpine plant communities in Switzerland, focusing on the elevational range of the widely distributed cushion plant Silene acaulis and the interactions of this facilitator species with other plants. Examining size distributions and densities, we found that disturbance appears to favor individual Silene growth at middle elevations. However, it has negative effects at the population level, as evidenced by a reduction in population density and reproductive indices. Disturbance synergistically interacts with the effects of elevation to reduce species richness at low and high elevations, an effect not mitigated by Silene. In fact, we find predominantly competitive interactions, both by Silene on its hosted and neighboring species and by neighboring (but not hosted) species on Silene. Our results indicate that disturbance can be beneficial for Silene individual performance, potentially through changes in its neighboring species community. However, possible reduced recruitment in disturbed areas could eventually lead to population declines. While other studies have shown that light to moderate disturbances can maintain high species diversity, our results emphasize that heavier disturbance reduces species richness, diversity, as well as percent cover, and adversely affects cushion plants and that these effects are not substantially reduced by plant–plant interactions. Heavily disturbed alpine systems could therefore be at greater risk for upward encroachment of lower elevation species in a warming world.
Stage duration distributions in matrix population models
Authors: Okuyama Toshinori 
Published: July 2018

AbstractMatrix population models are a standard tool for studying stage‐structured populations, but they are not flexible in describing stage duration distributions. This study describes a method for modeling various such distributions in matrix models. The method uses a mixture of two negative binomial distributions (parametrized using a maximum likelihood method) to approximate a target (true) distribution. To examine the performance of the method, populations consisting of two life stages (juvenile and adult) were considered. The juvenile duration distribution followed a gamma distribution, lognormal distribution, or zero‐truncated (over‐dispersed) Poisson distribution, each of which represents a target distribution to be approximated by a mixture distribution. The true population growth rate based on a target distribution was obtained using an individual‐based model, and the extent to which matrix models can approximate the target dynamics was examined. The results show that the method generally works well for the examined target distributions, but is prone to biased predictions under some conditions. In addition, the method works uniformly better than an existing method whose performance was also examined for comparison. Other details regarding parameter estimation and model development are also discussed.
CHIIMP: An automated high‐throughput microsatellite genotyping platform reveals greater allelic diversity in wild chimpanzees
Authors: Barbian Hannah J. , Connell Andrew Jesse , Avitto Alexa N. , Russell Ronnie M. , Smith Andrew G. , Gundlapally Madhurima S. , Shazad Alexander L. , Li Yingying , Bibollet‐Ruche Frederic , Wroblewski Emily E. , Mjungu Deus , Lonsdorf Elizabeth V. , Stewart Fiona A. , Piel Alexander K. , Pusey Anne E. , Sharp Paul M. , Hahn Beatrice H. 
Published: July 2018

AbstractShort tandem repeats (STRs), also known as microsatellites, are commonly used to noninvasively genotype wild‐living endangered species, including African apes. Until recently, capillary electrophoresis has been the method of choice to determine the length of polymorphic STR loci. However, this technique is labor intensive, difficult to compare across platforms, and notoriously imprecise. Here we developed a MiSeq‐based approach and tested its performance using previously genotyped fecal samples from long‐term studied chimpanzees in Gombe National Park, Tanzania. Using data from eight microsatellite loci as a reference, we designed a bioinformatics platform that converts raw MiSeq reads into locus‐specific files and automatically calls alleles after filtering stutter sequences and other PCR artifacts. Applying this method to the entire Gombe population, we confirmed previously reported genotypes, but also identified 31 new alleles that had been missed due to sequence differences and size homoplasy. The new genotypes, which increased the allelic diversity and heterozygosity in Gombe by 61% and 8%, respectively, were validated by replicate amplification and pedigree analyses. This demonstrated inheritance and resolved one case of an ambiguous paternity. Using both singleplex and multiplex locus amplification, we also genotyped fecal samples from chimpanzees in the Greater Mahale Ecosystem in Tanzania, demonstrating the utility of the MiSeq‐based approach for genotyping nonhabituated populations and performing comparative analyses across field sites. The new automated high‐throughput analysis platform (available at https://github.com/ShawHahnLab/chiimp) will allow biologists to more accurately and effectively determine wildlife population size and structure, and thus obtain information critical for conservation efforts.
Genome‐wide SNP analysis unveils genetic structure and phylogeographic history of snow sheep (Ovis nivicola) populations inhabiting the Verkhoyansk Mountains and Momsky Ridge (northeastern Siberia)
Authors: Dotsev Arsen V. , Deniskova Tatiana E. , Okhlopkov Innokentiy M. , Mészáros Gabor , Sölkner Johann , Reyer Henry , Wimmers Klaus , Brem Gottfried , Zinovieva Natalia A. 
Published: July 2018

AbstractInsights into the genetic characteristics of a species provide important information for wildlife conservation programs. Here, we used the OvineSNP50 BeadChip developed for domestic sheep to examine population structure and evaluate genetic diversity of snow sheep (Ovis nivicola) inhabiting Verkhoyansk Range and Momsky Ridge. A total of 1,121 polymorphic SNPs were used to test 80 specimens representing five populations, including four populations of the Verkhoyansk Mountain chain: Kharaulakh Ridge–Tiksi Bay (TIK, n = 22), Orulgan Ridge (ORU, n = 22), the central part of Verkhoyansk Range (VER, n = 15), Suntar‐Khayata Ridge (SKH, n = 13), and Momsky Ridge (MOM, n = 8). We showed that the studied populations were genetically structured according to a geographic pattern. Pairwise FST values ranged from 0.044 to 0.205. Admixture analysis identified K = 2 as the most likely number of ancestral populations. A Neighbor‐Net tree showed that TIK was an isolated group related to the main network through ORU. TreeMix analysis revealed that TIK and MOM originated from two different ancestral populations and detected gene flow from MOM to ORU. This was supported by the f3 statistic, which showed that ORU is an admixed population with TIK and MOM/SKH heritage. Genetic diversity in the studied groups was increasing southward. Minimum values of observed (Ho) and expected (He) heterozygosity and allelic richness (Ar) were observed in the most northern population—TIK, and maximum values were observed in the most southern population—SKH. Thus, our results revealed clear genetic structure in the studied populations of snow sheep and showed that TIK has a different origin from MOM, SKH, and VER even though they are conventionally considered a single subspecies known as Yakut snow sheep (Ovis nivicola lydekkeri). Most likely, TIK was an isolated group during the Late Pleistocene glaciations of Verkhoyansk Range.
Diagnosing and grading heart failure with tomographic perfusion lung scintigraphy: validation with right heart catheterization
Authors: Jögi Jonas , Al‐Mashat Mariam , Rådegran Göran , Bajc Marika , Arheden Håkan 
Published: July 2018

AbstractAimsPulmonary congestion remains a diagnostic challenge in patients with heart failure (HF). The recommended method, chest X‐ray (CXR), lacks in accuracy, whereas quantitative tomographic lung scintigraphy [ventilation/perfusion single‐photon emission computed tomography (V/P SPECT)] has shown promising results but needs independent validation. The aim of this study is to evaluate V/P SPECT as a non‐invasive method to assess and quantify pulmonary congestion in HF patients, using right heart catheterization as reference method. The secondary objective was to investigate the performance of V/P SPECT in the clinical setting compared with CXR.Methods and resultsForty‐six consecutive patients with HF that were under consideration for heart transplantation were studied prospectively. All participants were examined with V/P SPECT, CXR, and right heart catheterization. Pulmonary artery wedge pressure served as reference method. Quantitative perfusion gradients were derived from V/P SPECT images. Ventilation/perfusion single‐photon emission computed tomography images were also assessed both by expert readers and clinical nuclear medicine physicians. Expert readers correctly identified 87% of all patients with an elevated pulmonary artery wedge pressure > 15 mmHg. The average sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for V/P SPECT assessed by the expert readers were 87%, 72%, 85%, and 75%, respectively. In the clinical nuclear medicine setting, V/P SPECT had 87% sensitivity, 63% specificity, 81% PPV, and 71% NPV. Clinically, V/P SPECT outperformed CXR, which had 27% sensitivity, 75% specificity, 67% PPV, and 35% NPV.ConclusionsVentilation/perfusion single‐photon emission computed tomography can be used as a non‐invasive method to diagnose and quantify pulmonary congestion in patients with HF and is more accurate than CXR in diagnosing pulmonary congestion in the clinical setting.
Low‐complexity heuristics to beam selection and rate adaptation in sparse massive MIMO systems
Authors: Valduga Samuel T. , Deneire Luc , Aparicio‐Pardo Ramon , de Almeida André L. F. , Maciel Tarcisio F. , Mota João C. M. 
Published: July 2018

AbstractIn this work, we propose a novel formulation for a precoder design considering practical rate assignment based on the modulation and coding scheme of the long‐term evolution table, beam selection, and power optimization, which exploits the geometric sparsity of the multiuser massive multiple‐input–multiple‐output channel. We consider two different channel models and provide an optimal solution for the joint beam selection and power optimization as well as a heuristic using Lagrangian relaxation. Assuming knowledge of the beamspace channel, the beamspace precoder consists in selecting and optimizing the power of the beams steered to the user equipments (UEs) in order to maximize the signal‐to‐interference‐plus‐noise ratio at the UE. Furthermore, we propose three additional simple heuristics with low complexity. For these three heuristics, we solve the problem in two steps: (1) selection of beams based on the maximal ratio transmission principle and (2) power allocation per UE. Simulation results show that our optimal solution can achieve a better performance than the zero‐forcing beamforming scheme in the high‐sparsity scenarios. Besides, compared to the linear maximal ratio transmission precoder, the proposed low‐complexity heuristics improve the performance under a scenario with channel sparsity.
A Slope Right‐angle Turn Applied in the Flow Channel Promotes Water Management in Proton Exchange Membrane Fuel Cells
Authors: Liu H. C. , Tan J. , Cheng L. S. , Yang W. M. 
Published: July 2018

AbstractEffective water removal and transport in the flow field is significantly important to the critical water management in proton exchange membrane fuel cells (PEMFCs). In this work, a slope turn was proposed in the hydrophobic channel of the multi‐serpentine flow field, and the transport and dynamics of water in the modified flow channel were numerically investigated with the volume‐of‐fluid method. The simulation results indicated that, with the presence of the slope turn, the water droplet can be effectively detached from the surface of the gas diffusion layer although the channel walls are hydrophobic. Meanwhile, the hydrophobic channel walls are beneficial to decrease interfacial resistance of water transport, avoiding water accumulation in the flow channel. The wall contact angle, slope angle and gas flow velocity are three important factors which significantly affect water behavior and pressure drop in the flow channel. For considered cases in this work, the appropriate wall contact angle, slope angle, and gas flow velocity were proved to be 140°, 110°, and higher than 2 m s−1, respectively.
MicroRNA Sequencing Identifies a Serum MicroRNA Panel, Which Combined With Aspartate Aminotransferase to Platelet Ratio Index Can Detect and Monitor Liver Disease in Pediatric Cystic Fibrosis
Authors: Calvopina Diego A. , Chatfield Mark D. , Weis Anna , Coleman Miranda A. , Fernandez‐Rojo Manuel A. , Noble Charlton , Ramm Louise E. , Leung Daniel H. , Lewindon Peter J. , Ramm Grant A. 
Published: July 2018

Cystic fibrosis (CF)‐associated liver disease (CFLD) is a hepatobiliary complication of CF. Current diagnostic modalities rely on nonspecific assessments, whereas liver biopsy is the gold standard to assess severity of fibrosis. MicroRNAs (miRNAs) regulate liver disease pathogenesis and are proposed as diagnostic biomarkers. We investigated the combined use of serum miRNAs and aspartate aminotransferase (AST) to platelet ratio (APRI) to diagnose and assess CFLD severity. This was a cross‐sectional cohort study of the circulatory miRNA signature of 124 children grouped by clinical, biochemical, and imaging assessments as follows: CFLD (n = 44), CF patients with no evidence of liver disease (CFnoLD; n = 40), and healthy controls (n = 40). Serum miRNAs were analyzed using miRNA sequencing (miRNA‐Seq). Selected differentially expressed serum miRNA candidates were further validated by qRT‐PCR and statistical analysis performed to evaluate utility to predict CFLD and fibrosis severity validated by liver biopsy, alone or in combination with APRI. Serum miR‐122‐5p, miR‐365a‐3p, and miR‐34a‐5p levels were elevated in CFLD compared to CFnoLD, whereas miR‐142‐3p and let‐7g‐5p were down‐regulated in CFLD compared to CFnoLD. Logistic regression analysis combining miR‐365a‐3p, miR‐142‐3p, and let‐7g‐5p with APRI showed 21 times greater odds of accurately predicting liver disease in CF with an area under the receiver operating characteristics curve (AUROC) = 0.91 (sensitivity = 83%, specificity = 92%; P < 0.0001). Expression levels of serum miR‐18a‐5p were correlated with increasing hepatic fibrosis (HF) stage in CFLD (rs = 0.56; P < 0.0001), showing good diagnostic accuracy for distinguishing severe (F3‐F4) from mild/moderate fibrosis (F0‐F2). A unit increase of miR‐18a‐5p showed a 7‐fold increased odds of having severe fibrosis with an AUROC = 0.82 (sensitivity = 93%, specificity = 73%; P = 0.004), indicating its potential to predict fibrosis severity. Conclusion: We identified a distinct circulatory miRNA profile in pediatric CFLD with potential to accurately discriminate liver disease and fibrosis severity in children with CF.
Role of exosomal competing endogenous RNA in patients with hepatocellular carcinoma
Authors: Abd El Gwad Asmaa , Matboli Marwa , El‐Tawdi Ahmed , Habib Eman K. , Shehata Hanan , Ibrahim Doaa , Tash Fathy 
Published: July 2018

AbstractRecent research has tried to use exosomal RNAs (coding and noncoding) as potential diagnostic markers for hepatocellular carcinoma (HCC). Initially, by using bioinformatics, we selected an HCC‐exosomal RNA‐based biomarker panel. The choice of this panel depends on the integration of Ras‐related in brain (RAB11A) gene expression and its competing endogenous network. This network includes long noncoding RNA RP11‐513I15.6 (lncRNA‐RP11‐513I15.6) and microRNA‐1262 (miR‐1262). Secondly, we tried to validate the expression of this network in the sera of 60 patients with HCC in comparison with 42 chronic hepatitis C virus‐infected patients and 18 healthy controls. Then we assessed the diagnostic efficiency of this panel using a receiver operating characteristic curve analysis. The panel of 3 exosomal RNA‐based biomarkers (lncRNA‐RP11‐513I15.6, miR‐1262, and RAB11A) showed excellent sensitivity and specificity in discriminating patients with HCC from patients with chronic hepatitis C virus and healthy controls. Among these 3 RNAs, serum RAB11A mRNA was the most independent prognostic factor. The selected circulatory exosomal RNA‐based biomarker panel showed its ability to be used as a diagnostic and prognostic biomarker tool for HCC. Moreover, these biomarkers could be therapeutic targets.
Feasibility of using ultra‐low pulse rate fluoroscopy during routine diagnostic coronary angiography
Authors: Badawy Mohamed Khaldoun , Scott Matthew , Farouque Omar , Horrigan Mark , Clark David J. , Chan Robert K. 
Published: July 2018

AbstractIntroductionCoronary angiogram, while a powerful diagnostic tool in coronary artery disease, is not without an associated risk from ionising radiation. There are a number of factors that influence the amount of radiation the patient receives during the procedure, some of which are under the control of the operator. One of these is an adjustment of the fluoroscopic pulse rate. This study aims to assess the feasibility of using ultra‐low pulse rate (3 pulses per second(pps)) fluoroscopy during routine diagnostic coronary angiogram procedures and the effect it has on fluoroscopy time, diagnostic clarity and radiation dose.MethodsA retrospective study of three operators each undertaking 50 coronary angiogram procedures was performed. One of the operators used a pulse rate of 3 pps and 6 pps for fluoroscopic screening while the control groups used the standard 10 pps mode utilised at this centre.ResultsResults demonstrated no reduction of diagnostic clarity, up to a 58% reduction in Dose Area Product and no increase in fluoroscopy time with the 3 pps setting.ConclusionsFindings from this pilot study suggest that utilisation of ultra‐low pulse rate fluoroscopy in routine transfemoral diagnostic coronary angiography in the catheterisation laboratory is feasible.