bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrapopulation foraging niche variation between phenotypes and genotypes of Spirit bear populations
Authors: Service Christina N. , Ingram Travis , Reimchen Thomas E. , Darimont Chris T. 
Published: April 2021

AbstractForaging niche variation within a species can contribute to the maintenance of phenotypic diversity. The multiniche model posits that phenotypes occupying different niches can contribute to the maintenance of balanced polymorphisms. Using coastal populations of black bears (Ursus americanus kermodei)from British Columbia, Canada, we examined potential foraging niche divergence between phenotypes (black and white “Spirit” coat color) and between genotypes (black‐coated homozygote and heterozygous). We applied the Bayesian multivariate models, with biotracers of diet (δ13C and δ15N) together comprising the response variable, to draw inference about foraging niche variation. Variance–covariance matrices from multivariate linear mixed‐effect models were visualized as the Bayesian standard ellipses in δ13C and δ15N isotopic space to assess potential seasonal and annual niche variation between phenotypes and genotypes. We did not detect a difference in annual isotopic foraging niche area in comparisons between genotypes or phenotypes. Consistent with previous field experimental and isotopic analyses, however, we found that white phenotype Spirit bears were modestly more enriched in δ15N during the fall foraging season, though with our modest sample sizes these results were not significant. Although also not statistically significant, variation in isotopic niches between genotypes revealed that heterozygotes were moderately more enriched in δ13C along hair segments grown during fall foraging compared with black‐coated homozygotes. To the extent to which the pattern of elevated δ15N and δ13C may signal the consumption of salmon (Oncorhynchusspp.), as well as the influence of salmon consumption on reproductive fitness, these results suggest that black‐coated heterozygotes could have a minor selective advantage in the fall compared with black‐coated homozygotes. More broadly, our multivariate approach, coupled with knowledge of genetic variation underlying a polymorphic trait, provides new insight into the potential role of a multiniche mechanism in maintaining this rare morph of conservation priority in Canada's Great Bear Rainforest and could offer new understanding into polymorphisms in other systems.
A preliminary isotope‐based evapotranspiration partitioning approach for tropical Costa Rica
Authors: Iraheta Alberto , Birkel Christian , Benegas Laura , Ríos Ney , Sánchez‐Murillo Ricardo , Beyer Matthias 
Published: April 2021

AbstractSpatially and seasonally distributed information on transpiration (T) fluxes is limited in the tropics. Here, we applied a coupled isotope mass balance model to separate water fluxes of T and evapotranspiration (ET) from precipitation (P). The mean annual T was estimated at a resolution of 100 m for Costa Rica (51,100 km2) and a partitioning of monthly T and evaporation (E) for the 2370‐km2 San Carlos catchment. The dominant flux in the forest ecosystems was T with a mean annual T of 1086 mm that ranged from 700 mm in Tropical Montane Very Humid Forest to 1400 mm in Subtropical and Tropical Low Montane Rainforests. We estimated an average 85% of ET was T, which is concurrent with expectations for forested tropical regions, but varied according to model parameterization and data sources. A model comparison exercise showed a range of mean annual T estimates from 988 to 1465 mm and a range of T/P from 0.35 to 0.5 with temperature and relative humidity exhibiting the highest impact on the model results. Across Costa Rica, we estimated an average loss of precipitation by T of 38% (1085 mm), whereas interception (I) constitutes 10% (230 mm) and direct evaporation (E) only 7% (192 mm). Similarly, the results at the catchment scale indicated that monthly T contributes 76% (85‐mm monthly average) to total ET and E corresponds to 24% (24‐mm monthly average). The T rates exhibited an opposite seasonality to rainfall with highest T over the drier months from December to April with a peak in March (101–144 mm) and the minimum T in September (53–71 mm). Around 17% (79–130 mm) of precipitation over the catchment area is lost to T, both E (10–35 mm) and I (15–38 mm) correspond to 5%. Despite the inherent uncertainties of the data assumptions and simplifications, including data interpolation errors, the coupled isotope mass balance model showed in comparison to other global products reasonable water partitioning for different ecosystems in Costa Rica and the San Carlos catchment area. These results can help to evaluate the impact of land cover conversion on the hydrological cycle in Costa Rica, and the simple isotope‐based model could be transferred to different biomes of the tropics.
Synthetic Strategies towards Imidazopyridinones and 7‐Azaoxindoles and their Evaluation as Antibacterial Agents
Authors: Blindheim Fredrik Heen , Olsen Cecilie Elisabeth , Krogh Søgaard Caroline , Otterlei Marit , Sundby Eirik , Hoff Bård Helge 
Published: April 2021

AbstractImidazopyridinones and 7‐azaoxindoles are two classes of heterocyclic compounds with only limited previous use in organic and medicinal chemistry. Various synthetic methods and routes have been evaluated to identify safe and robust chemistry to advanced imidazopyridinone building blocks and inhibitor structures. Preparation of the 7‐azaoxindoles was challenged by instability of the core scaffold. Key to the successful isolation of the target structure was development of a mild Suzuki cross‐coupling in non‐aqueous media. The imidazopyridinones were potent inhibitors of the E. coli thymidylate monophosphate kinase, while the 7‐azaoxindole showed low activity. The compounds were inactive in cell‐based studies, indicating poor cell wall penetration.
Synthesis of the C1−C16 Polyol‐Containing Macrolactone of 13‐Desmethyl Lyngbouilloside, an Unnatural Analog of the Originally Assigned Structure of (−)‐Lyngbouilloside
Authors: Ganguly Arghya , Javed Salim , Bodugam Mahipal , Dissanayake Gihan C. , Chegondi Rambabu , Hanson Paul R. 
Published: April 2021

AbstractThe synthesis of the C1−C16 polyol‐containing macrolactone of 13‐desmethyl lyngbouilloside, an unnatural analog of the originally assigned structure of (−)‐lyngbouilloside is reported. Synthesis of the C1−C16 acyclic backbone is achieved via iterative use of a phosphate tether‐mediated one‐pot sequential, RCM/CM/chemoselective diimide reduction, with concomitant use of a regio‐ and diastereoselective cuprate addition using Me2Zn/CuCN ⋅ 2LiCl or Pd‐catalyzed reductive allylic transposition, respectively on bicyclo[4.3.1]phosphate‐containing subunits. Subsequent oxidative cleavage and Roskamp homologation completes the pathway to the C1−C16 acyclic fragment. Two routes to the macrocyclic core were explored with mixed success, (i) a Boeckman‐type acylketene trapping of the C13 secondary carbinol and (ii) an alternative route employing acid‐catalyzed pyran‐mixed ketal formation via reaction of the C7 secondary carbinol with the β‐keto ester using trimethylorthoformate, and subsequent Yamaguchi cyclization.
Bayesian estimation of the exact affine Stone index demand system: Replicating the Lewbel and Pendakur (2009) results
Authors: Ramírez‐Hassan Andrés 
Published: April 2021

SummaryThis paper proposes a Bayesian approach to perform inference in the exact affine Stone index (EASI) demand system that was proposed by Lewbel and Pendakur (2009), while taking into account nonlinearity and endogeneity. A Bayesian approach enables us to easily handle censored data, test and impose inequality restrictions (strict cost monotonicity) and concavity of the cost function, and perform inference of nonlinear functions of the parameter estimates as by‐product of the posterior chains. We compare our proposal with Lewbel and Pendakur (2009)'s results, based on iterative linear three‐stage least squares (3SLS). Although we found no statistically significant differences in point estimates between these two approaches, it seems that ignoring censoring overestimates precision.
Upregulated lnc‐HZ02 and miR‐hz02 inhibited migration and invasion by downregulating the FAK/SRC/PI3K/AKT pathway in BPDE‐treated trophoblast cells
Authors: Guo Jiarong , Li Rui , Xu Zhongyan , Tian Peng , Wang Rong , Li Youzhu , Qiu Xia , Zou Peng , He Mei , Ao Lin , Liu Qicai , Zhang Huidong 
Published: April 2021

AbstractBPDE (benzo(a)pyren‐7,8‐dihydrodiol‐9,10‐epoxide), a metabolite of environmental carcinogenic BaP, weakens the migration and invasion of human villous trophoblast cells and may further induce miscarriage. However, the underlying mechanisms remain largely unknown. In this study, we identified that in trophoblast Swan 71 and HTR‐8/SVneo cells, miR‐hz02 upregulates the level of lnc‐HZ02, which inhibits the expression of an RNA‐binding protein HuR. HuR could interact with FAK mRNA and promote its mRNA stability, thus upregulating the FAK level and the FAK/SRC/PI3K/AKT pathway, and finally maintaining the normal migration and invasion of trophoblast cells. If trophoblast cells are exposed to BPDE, both miR‐hz02 and lnc‐HZ02 are upregulated, which reduce the level of HuR, weaken the interactions of HuR with FAK mRNA, downregulate FAK level and the FAK/SRC/PI3K/AKT pathway, and finally inhibit cell migration and invasion. This study provides a novel scientific understanding of the dysfunctions of human trophoblast cells.
Free energy change estimation: The Divide and Conquer MBAR method
Authors: Jia Xiangyu , Ge Hu , Mei Ye 
Published: April 2021

AbstractIn the present study, the Divide and Conquer MBAR (DC‐MBAR) method is proposed to predict the free energies based on the data sampled by multi‐states simulations. For DC‐MBAR method, the overlap between any two alchemical states is calculated first and those with sufficient overlap are defined as the adjacent states. Unlike the traditional MBAR method, which calculates the free energy of each state using all the data at once, DC‐MBAR focuses on predicting the free energy changes between adjacent states. To estimate the free energy changes accurately, the other states with overlaps with the two adjacent states bigger than the defined threshold are included in the MBAR equation. At a specific threshold, the free energies predicted by DC‐MBAR are very close to those calculated by the traditional MABR method. Furthermore, DC‐MBAR scheme can reduce both the computation and memory cost. One important characteristic of DC‐MBAR method is linear scaling, which means the CPU time with the change of the number of states is a straight‐line relation. As the pair‐based calculations are mutually independent and parallelizable, all accessible CPU cores on the HPC cluster could be utilized, which makes DC‐MBAR strategy more efficient.
Myocardial T1 Values at 1.5 T: Normal Values for General Electric Scanners and Sex‐Related Differences
Authors: Meloni Antonella , Martini Nicola , Positano Vincenzo , D'Angelo Gennaro , Barison Andrea , Todiere Giancarlo , Grigoratos Chrysanthos , Barra Valerio , Pistoia Laura , Gargani Luna , Ripoli Andrea , Pepe Alessia 
Published: April 2021

BackgroundNo data are available about normal ranges for native T1 in human myocardium using General Electric (GE) scanners.PurposeTo establish normal ranges for myocardial T1 values and evaluate regional variability and the influence of physiological factors.Study typeProspective.SubjectsOne hundred healthy volunteers with normal electrocardiogram, no cardiovascular/systemic diseases, or risk factors (age range: 20–70 years; 50 females).Field Strength/Sequence1.5 T/Steady‐state free precession cine and a modified Look–Locker inversion recovery sequence in diastole (also in systole for 61 volunteers).AssessmentImage analysis was performed by operators with >10 years experience in cardiac MR using commercially available software. T1 values were calculated for 16 myocardial segments, and the global value was the mean. Segments were grouped according to circumferential region (anterior, septal, inferior, and lateral) and to level (basal, medial, apical). Twenty images were analyzed twice by the same operator and by a different operator to assess reproducibility.Statistical TestsIndependent‐samples t‐test or Mann–Whitney test; paired sample t‐test or Wilcoxon signed‐rank test; one‐way repeated measures ANOVA or Friedman tests; Pearson's or Spearman's correlation. Reproducibility evaluated using coefficient of variability (CoV).ResultsDue to artifacts and/or partial‐volume effects, 45/1600 (2.8%) segments were excluded. A good intra‐ and inter‐operator reproducibility was detected (CoV < 5%). There were significant differences in segmental T1 values (P < 0.05). A significant circumferential variability was present (P < 0.05): the mean native T1 value over the lateral region was significantly lower than in the other three regions. An increasing gradient from basal to apical slices was detected (P < 0.05). Segmental and global T1 values were not associated with age (range P = 0.052–0.911) but were significantly lower in males than in females (global: 993 ± 32 vs. 1037 ± 27 ms; P < 0.05) and significantly correlated with heart rate (range R for segmental values = 0.247–0.920; P < 0.05). Almost all segmental T1 values were inversely correlated with wall thickness (R from −0.233 to −0.514; P < 0.05). Systolic T1 values were significantly lower than diastolic values in basal anteroseptal segment, in all medial segments except the inferior one, and in all apical segments (P < 0.05).Data ConclusionMyocardial T1 values differ among myocardial regions, are influenced by sex, heart rate, and wall thickness and vary according to the cardiac cycle in healthy adults.Level of Evidence2Technical EfficacyStage 2
Determination of minor isotope ratios of individual uranium particles by accelerator mass spectrometry
Authors: Gao Jie , Zhao Yong‐Gang , He Ming , Zhao Qing‐Zhang , Shen Yan 
Published: April 2021

AbstractThe determination of uranium isotope ratios in uranium particle is an essential technique in the analysis of environmental samples for nuclear safeguards. At present, mass spectrometry has been widely used to measure isotope ratios of uranium particles. We developed a new analytical method for measuring minor isotope ratios of individual uranium particles directly. The technique includes single particle identification by energy dispersive X‐ray spectrometer (EDX), transfer by scanning electron microscope (SEM) combined with micromanipulator and isotope ratios analysis with accelerator mass spectrometry (AMS). The minor isotope ratios of individual uranium particles with four isotopic abundances and different sizes from certified reference materials were measured by AMS. The results show that the relative error (RE, i.e., the deviation of measured value from the certified value) of 234U/235U and 234U/236U isotope ratios was 9.0% and 19.3%, respectively, and the relative standard deviation (RSD) was within 9.9% and 16%, respectively. The minimum particle determined was about 2 μm. The method was found to be an alternative analytical means for nuclear safeguards.
Chromatomembrane preconcentration of phenols using a new 3D printed microflow cell followed by reversed‐phase HPLC determination
Authors: Moskvin L.N. , Rodinkov О.V. , Moskvin А.L. , Spivakovskii V. , Vlasov A.Y. , Bugaichenko A.S. , Samokhin А.S. , Nesterenko P.N. 
Published: April 2021

AbstractChromatomembrane process represents a universal approach to the separation of compounds in liquid–gas and liquid‐liquid phases systems. However, the broad application of chromatomembrane separation methods in chemical analysis is restricted by the absence of serially produced chromatomembrane flow cells and the difficulties of their laboratory production. The present work addresses the preparation of chromatomembrane flow cell by using 3D printing. Fused deposition modeling and stereolithography were modes for the production of the flow cell using acrylonitrile‐butadiene‐styrene and polyacrylate‐based Anycubic UV resins respectively. The separation and analytical performance of the 3D‐printed flow cell were compared with a polyimide unit fabricated by a milling machine, the trial addressing the determination of phenol in the air. The method is based on chromatomembrane absorption of the analytes in 95 μL of the aqueous phase positioned in the cell. Reversed‐phase HPLC with fluorimetric detection was applied for the determination of the absorbed analytes. The detection limit of phenols (phenol and m‐cresol) in the air was 0.9 μg/m3 by absorption preconcentration time of 10 min. The volumetric flow rate of the analyzed air through the chromatomembrane cell using an electrodriven aspirator was 0.1 L/min.
Direct Observation of Photo‐Induced Reversible Sol–Gel Transition in Block Copolymer Self‐Assembly Containing an Azobenzene Ionic Liquid
Authors: Mizuno Haruna , Hashimoto Kei , Shigenobu Keisuke , Kokubo Hisashi , Ueno Kazuhide , Watanabe Masayoshi 
Published: April 2021

AbstractUsing atomic force microscopy, the photo‐induced reversible changes in a block copolymer self‐assembly containing an azobenzene ionic liquid, which undergoes sol–gel transition is directly observed. This is the first report on the sol–gel transition of an ABA‐type block copolymer consisting of upper critical solution temperature (UCST)‐type A blocks in a photoresponsive ionic liquid mixture. The sol–gel transition is accompanied by an order‐to‐disorder structural change, which subsequently induces a change in the ionic conductivity. Surprisingly, the photo‐induced ionic conductivity and rheological changes occurs rapidly (≈30 s) despite the dense (≈80 wt%) polymeric system. The rapid structural change is probably attributable to the fast diffusion of the ionic liquid.
What is known about factors improving physiotherapists' adherence to high value interventions in nonspecific low back pain? A scoping review protocol
Authors: Shah Sweni , Prakash V. 
Published: April 2021

AbstractIntroductionDespite multiple guidelines providing best practice treatment recommendations for managing low back pain (LBP), current evidence suggests that physiotherapists across the world often provide costly, ineffective, unnecessary, even harmful care. The purpose of this scoping review is to establish the body of evidence regarding factors that improve or hinder physiotherapist's adherence to high‐value interventions in the management of non‐specific LBP.MethodsThis scoping review will be conducted based on the methodological framework for scoping review recommended by Arksey & O'Malley's and Levac. Three electronic databases will be searched: MEDLINE, CINAHL and SPORTDiscus. A search of grey literature will also be performed. The search will cover studies published in English from the inception of each database to the present date. The reference lists of all included reports and articles will be hand‐searched for additional results. Two independent reviewers will screen titles and abstracts for assessment against the eligibility criteria. Data will be extracted and presented in tabular form and a narrative summary that aligns with the review's aim.Ethics and disseminationThis scoping review does not require ethics approval. Results of this scoping review will be disseminated via conference presentation and/or publication in a scientific journal. We will also disseminate the results as part of stakeholder meetings with physiotherapists including clinicians, academicians, researchers and administrators managing non‐specific LBP. A summary of the key results will be shared across social networking sites in the form of infographics.
The cumulative incidence of dysphagia and dysphagia‐free survival in persons diagnosed with amyotrophic lateral sclerosis
Authors: Perry Bridget J. , Nelson Jason , Wong John B. , Kent David M. 
Published: April 2021

AbstractIntroduction/AimsDysphagia worsens mortality and quality of life for persons diagnosed with amyotrophic lateral sclerosis (ALS), yet our understanding of its incidence and timing remains limited. In this study we sought to estimate dysphagia incidence and dysphagia‐free survival over time.MethodsUsing data from the Pooled Resource Open‐Access ALS Clinical Trials Database, we compared characteristics of persons with and without dysphagia upon study entry. To account for competing mortality risk, we used Kaplan‐Meier curves to estimate the cumulative incidence of dysphagia and the median number of days until the development of dysphagia or death in those without dysphagia at study entry.ResultsPatients with dysphagia upon study entry were more likely to have bulbar onset and had faster rates of functional decline and shorter diagnostic delays. The cumulative incidence of new‐onset dysphagia was 44% at 1 year and 64% at 2 years after trial enrollment for those with spinal onset, and 85% and 92% for those with bulbar onset. The median duration of dysphagia‐free survival after trial enrollment was 11.5 months for those with spinal onset and 3.2 months for those with bulbar onset.DiscussionOur findings underscore the high risk for dysphagia development and support the need for early dysphagia referral and evaluation to minimize the risk of serious dysphagia‐related complications.
Numerical investigation of the effect of weather conditions on the escalation and propagation of fire‐induced domino effect
Authors: Malik Asher Ahmed , Nasif Mohammad Shakir , Mokhtar Ainul Akmar , Mohd Tohir Mohd Zahirasri 
Published: April 2021

AbstractFire‐induced domino accidents are less probable but highly consequent. Although past studies conducted risk assessment of such events, classical models were used for impact estimation. Moreover the influence of varying weather on evolution of fire domino effect was not investigated, where past research necessitates the use of computational fluid dynamics to perform such analysis. This paper adopts a consolidated risk analysis approach to perform consequence modeling using fire dynamics simulator. Various atmospheric conditions were incorporated in the model. The outcomes were used in probabilistic analysis to estimate the escalation probabilities. Risk of domino events was presented as domino levels. It was found that 37% reduction in humidity ratio resulted in 10% decrease in tanks failure time. At 3 and 6 m/s winds, the failure time of tank in flame direction reduced by 56% and 80%, whereas the escalation probability increased by 3 and 4 orders respectively. The tank farm failed in 11.3 and 12.85 min at 3 and 6 m/s respectively, which is less than the suggested mitigation time.
Phonological Awareness Materials in Utah Kindergartens: A Case Study in the Science of Reading
Authors: Brown Kathleen J. , Patrick Kelly C. , Fields Matthew K. , Craig Grace T. 
Published: April 2021

ABSTRACTSince well before the release of the National Reading Panel report in 2000, phonemic awareness has been an important topic for reading researchers. However, it is unclear the extent to which commercial materials for phonemic awareness instruction are consistent with that report and subsequent research. In the current study, we investigated the use of commercial kindergarten materials for such instruction in one state and suggest that the most widely used materials have areas of inconsistency with the science of reading. Notably, the commercial materials reviewed here did not take orthographic development into sufficient account. Additionally, the materials did not use letters and did not limit focus to one or two skills. Implications for classroom instruction, teacher education, commercial materials development, and future research are identified.