bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synergistic effect of graphene with graphene oxide, nanoclay, and nanosilica in enhancing the mechanical and barrier properties of bromobutyl rubber/epoxidized natural rubber composites
Authors: Aswathy T. R. , Dash Biswaranjan , Dey Pranab , Nair Sujith , Naskar Kinsuk 
Published: March 2021

AbstractThe present work aims to investigate the effect of hybrid nanofillers in bromobutyl rubber/epoxidized natural rubber (ENR 50) composites for developing highly air‐impermeable nanocomposites. The nanocomposites with hybrid nanofillers were prepared by a simple melt mixing method, and the morphology of the developed nanocomposites was studied using X‐Ray diffraction, transmission electron microscopy, and atomic force microscopy. Improvement in the mechanical, barrier and dynamic properties can be observed for hybrid nanocomposites compared to the composites filled with individual graphene nanoplatelets (GNPs). The strong interfacial attraction between GNP monolayers enhance its aggregation in nanocomposites. While, in the current study the results are showing that the addition of graphene oxide, nanoclay, and nanosilica enhances the dispersion of GNP in the composites. The homogeneous dispersion of GNP nanofillers will develop a tortuous pathway in the composites, which are responsible for their air barrier properties. Bound rubber content and dynamic strain measurements (Payne effect) show a maximum value for binary nanocomposites.
Green bonds as a tool against climate change?
Authors: Fatica Serena , Panzica Roberto 
Published: March 2021

AbstractAlthough green bonds are becoming increasingly popular in the corporate finance practice, little is known about their implications and effectiveness in terms of issuers' environmental engagement. With the use of matched bond‐issuer data, we test whether green bond issues are associated to a reduction in total and direct (Scope 1) emissions of nonfinancial companies. We find that, compared with conventional bond issuers with similar financial characteristics and environmental ratings, green issuers display a decrease in the carbon intensity of their assets after borrowing on the green segment. The decrease in emissions is more pronounced, significant and long‐lasting when we exclude green bonds with refinancing purposes, which is consistent with an increase in the volume of climate‐friendly activities due to new projects. We also find a larger reduction in emissions in case of green bonds that have external review, as well as those issued after the Paris Agreement.
Protein disulphide isomerase inhibition as a potential cancer therapeutic strategy
Authors: Powell Lauren E. , Foster Paul A. 
Published: March 2021

AbstractThe protein disulphide isomerase (PDI) gene family is a large, diverse group of enzymes recognised for their roles in disulphide bond formation within the endoplasmic reticulum (ER). PDI therefore plays an important role in ER proteostasis, however, it also shows involvement in ER stress, a characteristic recognised in multiple disease states, including cancer. While the exact mechanisms by which PDI contributes to tumorigenesis are still not fully understood, PDI exhibits clear involvement in the unfolded protein response (UPR) pathway. The UPR acts to alleviate ER stress through the activation of ER chaperones, such as PDI, which act to refold misfolded proteins, promoting cell survival. PDI also acts as an upstream regulator of the UPR pathway, through redox regulation of UPR stress receptors. This demonstrates the pro‐protective roles of PDI and highlights PDI as a potential therapeutic target for cancer treatment. Recent research has explored the use of PDI inhibitors with PACMA 31 in particular, demonstrating promising anti‐cancer effects in ovarian cancer. This review discusses the properties and functions of PDI family members and focuses on their potential as a therapeutic target for cancer treatment.
Transition to lanadelumab‐flyo from three medications for a hereditary angioedema patient with a variant in the SYTL2 gene: A case report
Authors: Burns Stephanie , Lewis Elena 
Published: March 2021

AbstractNon‐SERPING1 gene variant hereditary angioedema patients often need to take progesterone, attenuated androgens, and antifibrinolytics to control symptoms. These drugs may need to be tapered to extinction or reduced as lanadelumab‐flyo reaches maximum concentration.
Saved by anticoagulants: Incidental discovery of a misplaced defibrillator lead 6 years after implantation. Inadvertent lead placement inside the left ventricular cavity
Authors: Osman Abdelrahman , Ahmad Ali 
Published: March 2021

AbstractDevice insertion is a common cardiovascular procedure. Devices are implanted into the right heart, acting as a safeguard against systemic thromboembolism. Lead insertion into the left ventricle is rare, but carries dangerous consequences of thromboembolic events. Diagnosis and intervention of an inadvertently placed lead is essential. This is a case of a defibrillator lead inadvertently inserted into the left cavity, discovered 6 years after implantation.
Low‐dose aspirin‐induced gastric mucosal injury after Fontan surgery in an adolescent
Authors: Kakiuchi Toshihiko , Kumamoto Takashi , Koji Azusa , Matsuo Muneaki 
Published: March 2021

AbstractLow‐dose aspirin (LDA)–induced gastric mucosal injury always requires rigorous follow‐up while taking LDA, even in adolescents, and after a long time from the start of LDA.
One Stone Two Birds—Enantioselective Bimetallic Catalysis for α‐Amino Acid Derivatives with an Allene Unit
Authors: Xiao Junzhe , Xu Haibo , Huo Xiaohong , Zhang Wanbin , Ma Shengming 
Published: March 2021

Main observation and conclusionA highly enantioselective 2,3‐allenylation of acyclic and cyclic α‐imino carboxylates via a synergistic bimetallic Pd/Cu catalysis with the same commercially available (R,Rp)‐iPr‐FOXAP (also as Phosferrox, (R,R)‐[2‐(4’‐i‐propyloxazolin‐2’‐yl)ferrocenyl]diphenyl phosphine) ligand for both metals affording optically active 2,3‐butadienyl α‐amino acid derivatives in high to excellent yields with excellent enantioselectivities has been developed. The synthetic versatility of this reaction has been demonstrated by gram‐scale synthesis, a catalytic enantioselective synthesis of naturally occurring (S)‐2‐amino‐4,5‐hexadienoic acid A, and conversions to several useful chemicals, such as optically active α‐amino acids, β‐amino alcohols, potential chiral oxazoline ligands bearing an allenic moiety, and bicyclic ketone compounds. A mechanism involving the roles of two metals and the single chiral ligand has been extensively studied based on the isolation of key palladium pre‐catalyst and control experiments.
Mechanistic Study of Oxidoreductase AprQ Involved in Biosynthesis of Aminoglycoside Antibiotic Apramycin
Authors: Wang Jinxiu , Ma Suze , Ding Wei , Chen Tuo , Zhang Qi 
Published: March 2021

Main observation and conclusionThe aminoglycoside antibiotic apramycin contains a unique bicyclic octose moiety, and biosynthesis of this moiety involves an oxidoreductase AprQ. Unlike other known “Q” series proteins involved in aminoglycosides biosynthesis, AprQ does not work with an aminotransferase partner, and performs a four‐electron oxidation that converts a CH2OH moiety to a carboxylate group. In this study, we report mechanistic investigation of AprQ. We showed AprQ contains a flavin mononucleotide (FMN) cofactor, which is different from other known Q series enzymes that contain a flavin adenine dinucleotide (FAD) cofactor. A series of biochemical assays showed that AprQ is not a monooxygenase but a flavoprotein oxidase. Although molecular O2 is strictly required for reaction turnover, four‐electron oxidation can be achieved in the absence of O2 in single turnover condition. These findings establish the detailed catalytic mechanism of AprQ and expand the growing family of flavoprotein oxidases, an increasingly important class of biocatalysts.
A review of research on co‐training
Authors: Ning Xin , Wang Xinran , Xu Shaohui , Cai Weiwei , Zhang Liping , Yu Lina , Li Wenfa 
Published: March 2021

SummaryCo‐training algorithm is one of the main methods of semi‐supervised learning in machine learning, which explores the effective information in unlabeled data by multi‐learner collaboration. Based on the development of co‐training algorithm, the research work in recent years was further summarized in this article. In particular, three main steps of relevant co‐training algorithms are introduced: view acquisition, learners' differentiation, and label confidence estimation. Finally, we summarized the problems existing in the current co‐training methods, gave some suggestions for improvement, and looked forward to the future development direction of the co‐training algorithm.
Morpho‐physiological changes induced by soil environment modulate the compatibility of perennial ryegrass and white clover cultivars
Authors: Acuña Hernán , Sánchez Ma Paulina , Inostroza Luis 
Published: March 2021

AbstractThe effect of soil environment on cultivars compatibility was evaluated in a cutting field experiment during two growing seasons. A factorial combination of four perennial ryegrass (Lolium perenne L.; PR) and three white clover (Trifolium repens L.; WC) cultivars were grown on deep (DSS) and shallow (SSS) soils under irrigated conditions. Measurements included herbage accumulation (HA), root attributes, leaf chlorophyll content, and interception of photosynthetic radiation. The PR–WC compatibility was affected by soil environment. In both soil sites and growing seasons, the WC + PR herbage accumulations were similar but with different PR and WC partial accumulation. In DSS, the partial PR HA was 22% less than that observed in SSS; the partial WC HA was almost twice in DSS relative to SSS. In SSS, the WC stolon growing point numbers, stolon length, and stolon biomass increased 60, 88, and 94% relative to DSS, respectively. In the same way, the mixed sward increased root biomass and root length density, which was considered as a mechanism for improving plant resources capture from the soil. At cultivar level, the PR–WC compatibility was affected mainly by WC cultivar, and the effect of PR cultivar was fairly weak. The medium‐leaved WC cultivar ‘Will’ showed the greatest compatibility with PR, particularly with cultivar ‘Bealey’. These results are valuable when designing new management strategies for mixed sward production in marginal environments. Modern cultivars of PR have capacity for adapting to marginal environments; however, it is necessary to improve the competitive ability of WC to capture soil resources under marginal soil conditions.
Tenofovir and emtricitabine concentrations in hair are comparable between individuals on tenofovir disoproxil fumarate versus tenofovir alafenamide‐based ART
Authors: Okochi Hideaki , Louie Alexander , Phung Nhi , Zhang Kevin , Tallerico Regina M. , Kuncze Karen , Spinelli Matthew A. , Koss Catherine A. , Benet Leslie Z. , Gandhi Monica 
Published: March 2021

AbstractTenofovir disoproxil fumarate (TDF) in combination with emtricitabine (FTC) is the backbone for both human immunodeficiency virus (HIV) treatment and pre‐exposure prophylaxis (PrEP) worldwide. Tenofovir alafenamide (TAF) with FTC is increasingly used in HIV treatment and was recently approved for PrEP among men‐who‐have‐sex‐with‐men. TDF and TAF are both metabolized into tenofovir (TFV). Antiretrovirals in plasma are taken up into hair over time, with hair levels providing a long‐term measure of adherence. Here, we report a simple, robust, highly sensitive, and validated high‐performance liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS)‐based analytical method for analyzing TFV and FTC from individuals on either TDF/FTC or TAF/FTC in small hair samples. TFV/FTC are extracted from ~5 mg hair and separated on a column using a gradient elution. The lower quantification limits are 0.00200 (TFV) and 0.0200 (FTC) ng/mg hair; the assay is linear up to 0.400 (TFV) and 4.00 (FTC) ng/mg hair. The intra‐day and inter‐day coefficients of variance (CVs) are 5.39–12.6% and 6.40–13.5% for TFV and 0.571–2.45% and 2.45–5.16% for FTC. TFV concentrations from participants on TDF/FTC‐based regimens with undetectable plasma HIV RNA were 0.0525 ± 0.0295 ng/mg, whereas those from individuals on TAF/FTC‐based regimens were 0.0426 ± 0.0246 ng/mg. Despite the dose of TFV in TDF being 10 times that of TAF, hair concentrations of TFV were not significantly different for those on TDF versus TAF regimens. Pharmacological enhancers (ritonavir and cobicistat) did not boost TFV concentrations in hair. In summary, we developed and validated a sensitive analytical method to analyze TFV and FTC in hair and found that hair concentrations of TFV were essentially equivalent among those on TDF and TAF.
Opportunities for forest sector emissions reductions: a state‐level analysis
Authors: Dugan Alexa J. , Lichstein Jeremy W. , Steele Al , Metsaranta Juha M. , Bick Steven , Hollinger David Y. 
Published: March 2021

AbstractThe forest sector can play a significant role in climate change mitigation. We evaluated forest sector carbon trends and potential mitigation scenarios in Vermont using a systems‐based modeling framework that accounts for net emissions from all forest sector components. These components comprise (1) the forest ecosystem, including land‐use change, (2) harvested wood products (HWP), and (3) substitution effects associated with using renewable wood‐based products and fuels in place of more emission‐intensive materials and fossil fuel‐based energy. We assessed baseline carbon trends from 1995 through 2050 using a business as usual (BAU) scenario. Emission reductions associated with different forest management and HWP scenarios were evaluated relative to the BAU scenario from 2020 to 2050. We estimated uncertainty for each forest sector component and used a Monte Carlo approach to estimate the distribution of cumulative total mitigation for each scenario relative to baseline. Our analysis indicates that the strength of the forest sector carbon sink in Vermont has been declining and will continue to decline over coming decades under the BAU scenario. However, several scenarios evaluated here could be effective in reducing emissions and enhancing carbon uptake. Shifting HWP to longer‐lived commodities resulted in a 14% reduction in net cumulative emissions by 2050, the largest reduction of all scenarios. A scenario that combined extending harvest rotations, utilizing additional harvest residues for bioenergy, and increasing forest productivity resulted in a 12% reduction in net cumulative emissions. Shifting commodities from pulp and paper to bioenergy showed a 7.3% reduction in emissions. In contrast, shortening rotations to increase harvests for bioenergy use resulted in a 5.5% increase in emissions. In summary, model simulations suggest that net emissions could be reduced by up to 14% relative to BAU, depending on the management and HWP‐use scenario. Combining multiple scenarios could further enhance reductions. However, realizing the full climate mitigation potential of these forests may be challenging due to socioeconomic barriers to implementation, as well as alternative management objectives that must be considered along with carbon sequestration.
Spatial and temporal dynamics of space use by free‐ranging domestic dogs Canis familiaris in rural Africa
Authors: Wilson‐Aggarwal Jared K. , Goodwin Cecily E. D. , Moundai Tchonfienet , Sidouin Metinou K. , Swan George J. F. , Léchenne Monique , McDonald Robbie A. 
Published: March 2021

AbstractVariation in the spatial ecology of animals influences the transmission of infections and so understanding host behavior can improve the control of diseases. Despite the global distribution of free‐ranging domestic dogs Canis familiaris and their role as reservoirs for zoonotic diseases, little is known about the dynamics of their space use. We deployed GPS loggers on owned but free‐ranging dogs from six villages in rural Chad, and tracked the movements of 174 individuals in the dry season and 151 in the wet season. We calculated 95% and core home ranges using auto‐correlated kernel density estimates (AKDE95 and AKDEcore), determined the degree to which their movements were predictable, and identified correlates of movement patterns. The median AKDE95 range in the dry season was 0.54 km2 and in the wet season was 0.31 km2, while the median AKDEcore range in the dry season was 0.08 km2 and in the wet season was 0.04 km2. Seasonal variation was, in part, related to owner activities; dogs from hunting households had ranges that were five times larger in the dry season. At least 70% of individuals were more predictably “at home” (<50 m from the household) throughout the day in the dry season, 80% of dogs demonstrated periodicity in activity levels (speed), and just over half the dogs exhibited periodicity in location (repeated space use). In the wet season, dogs mostly exhibited 24‐h cycles in activity and location, with peaks at midday. In the dry season, dogs exhibited both 12‐ and 24‐h cycles, with either a single peak at midday, or one peak between 06:00 and 12:00 and a second between 18:00 and 22:00. Strategies to control canine‐mediated zoonoses can be improved by tailoring operations to the local spatial ecology of free‐ranging dogs. Interventions using a door‐to‐door strategy in rural Chad would best conduct operations during the dry season, when access to dogs around their household more reliably exceeds 70% throughout the day. Given the importance of use in hunting for explaining variation in dog space‐use, targeting approaches to disease control at the household level on the basis of owner activities offers potential to improve access to dogs.
Antagonistic selection on body size and sword length in a wild population of the swordtail fish, Xiphophorus multilineatus: Potential for intralocus tactical conflict
Authors: Liotta Melissa N. , Abbott Jessica K. , Morris Molly R. , Rios‐Cardenas Oscar 
Published: March 2021

AbstractAlternative reproductive tactics (ARTs) have provided valuable insights into how sexual selection and life history trade‐offs can lead to variation within a sex. However, the possibility that tactics may constrain evolution through intralocus tactical conflict (IATC) is rarely considered. In addition, when IATC has been considered, the focus has often been on the genetic correlations between the ARTs, while evidence that the ARTs have different optima for associated traits and that at least one of the tactics is not at its optimum is often missing. Here, we investigate selection on three traits associated with the ARTs in the swordtail fish Xiphophorus multilineatus; body size, body shape, and the sexually selected trait for which these fishes were named, sword length (elongation of the caudal fin). All three traits are tactically dimorphic, with courter males being larger, deeper bodied and having longer swords, and the sneaker males being smaller, more fusiform and having shorter swords. Using measures of reproductive success in a wild population we calculated selection differentials, as well as linear and quadratic gradients. We demonstrated that the tactics have different optima and at least one of the tactics is not at its optimum for body size and sword length. Our results provide the first evidence of selection in the wild on the sword, an iconic trait for sexual selection. In addition, given the high probability that these traits are genetically correlated to some extent between the two tactics, our study suggests that IATC is constraining both body size and the sword from reaching their phenotypic optima. We discuss the importance of considering the role of IATC in the evolution of tactical dimorphism, how this conflict can be present despite tactical dimorphism, and how it is important to consider this conflict when explaining not only variation within a species but differences across species as well.
Measurement and analysis of interspecific spatial associations as a facet of biodiversity
Authors: Keil Petr , Wiegand Thorsten , Tóth Anikó B. , McGlinn Daniel J. , Chase Jonathan M. 
Published: March 2021

AbstractInterspecific spatial associations (ISA), which include co‐occurrences, segregations, or attractions among two or more species, can provide important insights into the spatial structuring of communities. However, ISA has primarily been examined in the context of understanding interspecific interactions, while other aspects of ISA, including its relations to other biodiversity facets and how it changes in the face of anthropogenic pressures, have been largely neglected. This is likely because it is unclear what makes ISA useful in a biodiversity context, little is known about the theoretical connections between ISA and other biodiversity facets, and there is a confusing variety of approaches to measuring ISA. Here, we first review the metrics of ISA. These include spatially implicit and explicit indices of association for binary, abundance, and point pattern data. We test and compare these approaches on empirical and simulated data, and we provide recommendations for how to use and interpret them in biodiversity science. We argue that measurements of ISA are more informative when they are spatially explicit (i.e., distance dependent). We then review links of ISA to other classical biodiversity facets, such as alpha, beta, and gamma diversity, and show that they mostly fail to reflect changes/variation in ISA, with the exception of average pairwise beta diversity. This underscores the need for a specific focus on ISA in large‐scale biodiversity assessments. Finally, we argue that there are important, and underappreciated, reasons to study ISA that are unrelated to its link to biotic interactions. Specifically, ISA can provide strong tests of biodiversity theories that require multiple patterns to benchmark against, and it can be explored for potentially predictive macroecological patterns.
How mutualisms influence the coexistence of competing species
Authors: Johnson Christopher A. 
Published: March 2021

AbstractMutualisms are ubiquitous in nature and are thought to play important roles in the maintenance of biodiversity. For biodiversity to be maintained, however, species must coexist in the face of competitive exclusion. Chesson’s coexistence theory provides a mechanistic framework for evaluating coexistence, yet mutualisms are conspicuously absent from coexistence theory and there are no comparable frameworks for evaluating how mutualisms affect the coexistence of competiting species. To address this conceptual gap, I develop theory predicting how multitrophic mutualisms mediate the coexistence of species competing for mutualistic commodities and other limiting resources using the niche and fitness difference concepts of coexistence theory. I demonstrate that failing to account for mutualisms can lead to erroneous conclusions. For example, species might appear to coexist on resources alone, when the simultaneous incorporation of mutualisms actually drives competitive exclusion, or competitive exclusion might occur under resource competition, when in fact, the incorporation of mutualisms generates coexistence. Existing coexistence theory cannot therefore be applied to mutualisms without explicitly considering the underlying biology of the interactions. By discussing how the metrics derived from coexistence theory can be quantified empirically, I show how this theory can be operationalized to evaluate the coexistence consequences of mutualism in natural communities.