bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyhedral Oligomeric Silsesquioxanes (POSS)‐based Hybrid Materials: Molecular Design, Solution Self‐Assembly and Biomedical Applications
Authors: Fan Linfeng , Wang Xing , Wu Decheng 
Published: November 2020

AbstractOwing to the tremendous advantages and unique well‐defined nanoscale structure, polyhedral oligomeric silsesquioxanes (POSS) have received considerable interest in the design of novel organic‐inorganic hybrid nanomaterials with all manner of prominent capabilities, which is recognized as a new generation of promising materials for advanced applications of material science, engineering science and biomedical fields. Benefitting from the recent progress in combination of controlled/living polymerization and emerging click chemistry, POSS‐based hybrid materials with ingenious design, versatile topological structure and sophisticated multifunctionality have been successfully fabricated and developed into abundant well‐defined hybrid nanostructures with desired physicochemical properties. Tailor‐made amphiphilic molecular design and nanosized hybrid architecture provide opportunities for the self‐assembly of POSS‐based hybrid materials with unique hierarchical morphologies in selective solvents. Through the in‐depth understanding of structure‐properties relationship, POSS‐based hybrid materials can achieve the modulation of precise control of self‐assembling process and multi‐purpose applications with improved material performances. In this review, we summarize the recent advances of POSS‐based hybrid materials in molecular design, self‐assembly behavior in solutions and potential biomedical applications with main concerns on drug delivery, gene therapy, bioimaging and tissue engineering field. Finally, future directions and remaining challenges for further advancement of POSS‐based hybrid materials are proposed and discussed.
Morphological identification of thoracolumbar spinal afferent nerve endings in mouse uterus
Authors: Dodds Kelsi N. , Kyloh Melinda A. , Travis Lee , Beckett Elizabeth A. H. , Spencer Nick J. 
Published: November 2020

AbstractMajor sensory innervation to the uterus is provided by spinal afferent nerves, whose cell bodies lie predominantly in thoracolumbar dorsal root ganglia (DRG). While the origin of the cell bodies of uterine spinal afferents is clear, the identity of their sensory endings has remained unknown. Hence, our major aim was to identify the location, morphology, and calcitonin gene‐related peptide (CGRP)‐immunoreactivity of uterine spinal afferent endings supplied by thoracolumbar DRG. We also sought to determine the degree of uterine afferent innervation provided by the vagus nerve. Using an anterograde tracing technique, nulliparous female C57BL/6 mice were injected unilaterally with biotinylated dextran into thoracolumbar DRG (T13‐L3). After 7–9 days, uterine horns were stained to visualize traced nerve axons and endings immunoreactive to CGRP. Whole uteri from a separate cohort of animals were injected with retrograde neuronal tracer (DiI) and dye uptake in nodose ganglia was examined. Anterogradely labeled axons innervated each uterine horn, these projected rostrally or caudally from their site of entry, branching to form varicose endings in the myometrium and/or vascular plexus. Most spinal afferent endings were CGRP‐immunoreactive and morphologically classified as “simple‐type.” Rarely, uterine nerve cell bodies were labeled in nodose ganglia. Here, we provide the first detailed description of spinal afferent nerve endings in the uterus of a vertebrate. Distinct morphological types of spinal afferent nerve endings were identified throughout multiple anatomical layers of the uterine wall. Compared to other visceral organs, uterine spinal afferent endings displayed noticeably less morphological diversity. Few neurons in nodose ganglia innervate the uterus.
CB2 receptor‐selective agonists as candidates for targeting infection, inflammation, and immunity in SARS‐CoV‐2 infections
Authors: Nagoor Meeran M. F. , Sharma Charu , Goyal Sameer N. , Kumar Sanjay , Ojha Shreesh 
Published: November 2020

AbstractThe COVID‐19 pandemic caused by SARS‐CoV‐2 is a deadly disease afflicting millions. The pandemic continues affecting population due to nonavailability of drugs and vaccines. The pathogenesis and complications of infection mainly involve hyperimmune‐inflammatory responses. Thus, therapeutic strategies rely on repurposing of drugs aimed at reducing infectivity and inflammation and modulate immunity favourably. Among, numerous therapeutic targets, the endocannabinoid system, particularly activation of cannabinoid type‐2 receptors (CB2R) emerged as an important one to suppress the hyperimmune‐inflammatory responses. Recently, potent antiinflammatory, antiviral and immunomodulatory properties of CB2R selective ligands of endogenous, plant, and synthetic origin were showed mediating CB2R selective functional agonism. CB2R activation appears to regulate numerous signaling pathways to control immune‐inflammatory mediators including cytokines, chemokines, adhesion molecules, prostanoids, and eicosanoids. Many CB2R ligands also exhibit off‐target effects mediating activation of PPARs, opioids, and TRPV, suggestive of adjuvant use with existing drugs that may maximize efficacy synergistically and minimize therapeutic doses to limit adverse/ side effects. We hypothesize that CB2R agonists, due to immunomodulatory, antiinflammatory, and antiviral properties may show activity against COVID‐19. Based on the organoprotective potential, relative safety, lack of psychotropic effects, and druggable properties, CB2R selective ligands might make available promising candidates for further investigation.
Centennial clonal stability of asexual Daphnia in Greenland lakes despite climate variability
Authors: Dane Maison , Anderson Nicholas John , Osburn Christopher L. , Colbourne John K. , Frisch Dagmar 
Published: November 2020

AbstractClimate and environmental condition drive biodiversity at many levels of biological organization, from populations to ecosystems. Combined with paleoecological reconstructions, palaeogenetic information on resident populations provides novel insights into evolutionary trajectories and genetic diversity driven by environmental variability. While temporal observations of changing genetic structure are often made of sexual populations, little is known about how environmental change affects the long‐term fate of asexual lineages. Here, we provide information on obligately asexual, triploid Daphnia populations from three Arctic lakes in West Greenland through the past 200–300 years to test the impact of environmental change on the temporal and spatial population genetic structure. The contrasting ecological state of the lakes, specifically regarding salinity and habitat structure may explain the observed lake‐specific clonal composition over time. Palaeolimnological reconstructions show considerable regional environmental fluctuations since 1,700 (the end of the Little Ice Age), but the population genetic structure in two lakes was almost unchanged with at most two clones per time period. Their local populations were strongly dominated by a single clone that has persisted for 250–300 years. We discuss possible explanations for the apparent population genetic stability: (a) persistent clones are general‐purpose genotypes that thrive under broad environmental conditions, (b) clonal lineages evolved subtle genotypic differences unresolved by microsatellite markers, or (c) epigenetic modifications allow for clonal adaptation to changing environmental conditions. Our results motivate research into the mechanisms of adaptation in these populations, as well as their evolutionary fate in the light of accelerating climate change in the polar regions.
Generalized model‐based solutions to false‐positive error in species detection/nondetection data
Authors: Clare John D. J. , Townsend Philip A. , Zuckerberg Benjamin 
Published: November 2020

AbstractDetection/nondetection data are widely collected by ecologists interested in estimating species distributions, abundances, and phenology, and are often imperfect. Recent model development has focused on accounting for both false‐positive and false‐negative errors given evidence that misclassification is common across many sampling protocols. To date, however, model‐based solutions to false‐positive error have largely addressed occupancy estimation. We describe a generalized model structure that allows investigators to account for false‐positive error in detection/nondetection data across a broad range of ecological parameters and model classes, and demonstrate that previously developed model‐based solutions are special cases of the generalized model. Simulation results demonstrate that estimators for abundance and migratory arrival time ignoring false‐positive error exhibit severe (20–70%) relative bias even when only 5–10% of detections are false positives. Bias increased when false‐positive detections were more likely to occur at sites or within occasions in which true positive detections were unlikely to occur. Models accounting for false‐positive error following the site‐confirmation or observation‐confirmation designs generally reduced bias substantially, even when few detections were confirmed as true or false positives or when the process model for false‐positive error was misspecified. Results from an empirical example focusing on gray fox (Urocyon cinereoargenteus) abundance in Wisconsin, USA reinforce concerns that biases induced by false‐positive error can also distort spatial predictions often used to guide decision making. Model sensitivity to false‐positive error extends well beyond occupancy estimation, but encouragingly, model‐based solutions developed for occupancy estimators are generalizable and effective across a range of models widely used in ecological research.
Parasite exposure and host susceptibility jointly drive the emergence of epidemics
Authors: Stewart Merrill Tara E. , Hall Spencer R. , Cáceres Carla E. 
Published: November 2020

AbstractParasite transmission is thought to depend on both parasite exposure and host susceptibility to infection; however, the relative contribution of these two factors to epidemics remains unclear. We used interactions between an aquatic host and its fungal parasite to evaluate how parasite exposure and host susceptibility interact to drive epidemics. In six lakes, we tracked the following factors from pre‐epidemic to epidemic emergence: (1) parasite exposure (measured observationally as fungal spores attacking wild‐caught hosts), (2) host susceptibility (measured experimentally as the number of fungal spores required to produce terminal infection), (3) host susceptibility traits (barrier resistance and internal clearance, both quantified with experimental assays), and (4) parasite prevalence (measured observationally from wild‐caught hosts). Tracking these factors over 6 months and in almost 7,000 wild‐caught hosts provided key information on the drivers of epidemics. We found that epidemics depended critically on the interaction of exposure and susceptibility; epidemics only emerged when a host population’s level of exposure exceeded its individuals’ capacity for recovery. Additionally, we found that host internal clearance traits (the hemocyte response) were critical in regulating epidemics. Our study provides an empirical demonstration of how parasite exposure and host susceptibility interact to inhibit or drive disease in natural systems and demonstrates that epidemics can be delayed by asynchronicity in the two processes. Finally, our results highlight how individual host traits can scale up to influence broad epidemiological patterns.
Vector preference and heterogeneity in host sex ratio can affect pathogen spread in natural plant populations
Authors: Bruns Emily , Pierce Laura , Antonovics Janis , Hood Michael 
Published: November 2020

AbstractVector‐borne diseases threaten human and agricultural health and are a critical component of the ecology of plants and animals. While previous studies have shown that pathogen spread can be affected by vector preferences for host infection status, less attention has been paid to vector preference for host sex, despite abundant evidence of sex‐specific variation in disease burden. We investigated vector preference for host infection status and sex in the sterilizing “anther‐smut” pathogen (Microbotryum) of the alpine carnation, Dianthus pavonius. The pathogen is transferred among hosts by pollinators that visit infected flowers and become contaminated with spores produced by infected anthers. The host plant has a mixed breeding system with hermaphrodites and females. In experimental floral arrays, pollinators strongly preferred healthy hermaphrodites over both females and diseased plants, consistently across different guilds of pollinators and over multiple years. Using an agent‐based model, we showed that pollinator preferences for sex can affect pathogen spread in populations with variable sex ratios, even if there is no preference for infection status. Our results demonstrate that vector preferences for host traits other than infection status can play a critical role in pathogen transmission dynamics when there is heterogeneity for those traits in the host population.
Anchor‐yield exposed column bases for minimizing residual deformations in seismic‐resistant steel moment frames
Authors: Inamasu Hiroyuki , de Castro e Sousa Albano , Güell Gerard , Lignos Dimitrios G. 
Published: November 2020

AbstractThis paper explores the concept of dissipative exposed column base connections by means of anchor rod yielding. This concept aims at enhancing the seismic performance of low‐rise steel moment‐resisting frames (MRFs). A mechanics‐based model is proposed that explicitly simulates a broad range of damage mechanisms observed in exposed column bases. The model is implemented in a frame finite element analysis program, and its hysteretic performance is validated with experimental data available in literature. Incorporating this modeling feature in standard nonlinear response history analyses offers new insights in steel MRF responses. It is shown that when low‐rise steel MRFs adopt a dissipative anchor‐yield column base concept, they are less likely to experience residual story drift ratios during low probability of occurrence seismic events. It is also found that low‐rise steel MRFs designed with nondissipative exposed column base connections are more prone to demolition than dissipative ones, due to their higher column residual axial shortening, particularly when ground motion duration is an important feature of the seismic hazard. Limitations of the present work are also discussed.
The moving discontinuous Galerkin finite element method with interface condition enforcement for compressible viscous flows
Authors: Kercher Andrew D. , Corrigan Andrew , Kessler David A. 
Published: November 2020

AbstractThe moving discontinuous Galerkin finite element method with interface condition enforcement is applied to the case of viscous flows. This method uses a weak formulation that separately enforces the conservation law, constitutive law, and the corresponding interface conditions in order to provide the means to detect interfaces or underresolved flow features. To satisfy the resulting overdetermined weak formulation, the discrete domain geometry is introduced as a variable, so that the method implicitly fits a priori unknown interfaces and moves the grid to resolve sharp, but smooth, gradients, achieving a form of anisotropic curvilinear r‐adaptivity. This approach avoids introducing low‐order errors that arise using shock capturing, artificial dissipation, or limiting. The utility of this approach is demonstrated with its application to a series of test problems culminating with the compressible Navier–Stokes solution to a Mach 5 viscous bow shock for a Reynolds number of 105 in two‐dimensional space. Time accurate solutions of unsteady problems are obtained via a space‐time formulation, in which the unsteady problem is formulated as a higher dimensional steady space‐time problem. The method is shown to accurately resolve and transport viscous structures without relying on numerical dissipation for stabilization.
Estimating freshness of ice storage rainbow trout using bioelectrical impedance analysis
Authors: Fan Xinru , Lin Xiaoyu , Wu Chunhua , Zhang Nana , Cheng Qiaofen , Qi Hang , Konno Kunihiko , Dong Xiuping 
Published: November 2020

AbstractThis study aimed to evaluate the freshness of ice stored rainbow trout by bioelectrical impedance measurements. Rigor mortis, ATP‐related components, K‐value, and hardness of rainbow trout muscle during storage were monitored along with impedance. The results showed that the progress of rigor mortis was accompanied by an increase in impedance. Impedance kept decreasing even in rigor state, and during the gradual resolution of rigor mortis with impedance change upon storage of fish was biphasic (r = −0.944, p < .01). Thus, when impedance decreased close to the lowest value, K‐value was only about 61.57 ± 0.52%, but still exhibited a high pertinence (r = −0.959, p < .01). A gradual decrease of the hardness of fish muscle upon storage of fish showed a close correlation (r = 0.981, p < .01) with impedance decrease. These results suggested that the impedance measurement has a great potential for predicting the freshness of the rainbow trout during ice storage.
A weak post‐acidification Lactobacillus helveticus UV mutant with improved textural properties
Authors: Guan Chengran , Chen Xuan , Zhao Ruifeng , Yuan Yuan , Huang Xinyuan , Su Jianbo , Ding Xiangli , Chen Xia , Huang Yujun , Gu Ruixia 
Published: November 2020

AbstractTo derive a mutant of L. helveticus SH2‐1 with the capacity of weak postacidification and high texturing, first, taking L. delbrueckii frs4‐1 and S. thermophilus grx02 as the controls, H+‐ATPase activity was demonstrated to be highly related to the postacidification of L. helveticus SH2‐1. Then, by detecting H+‐ATPase activity, the weak postacidify mutant of L. helveticus SH2‐1 (renamed as L. helveticus sh2‐5–66) was selected from 80 UV mutants. The pH and acidity of the milk fermented with L. helveticus sh2‐5–66 were separately 0.57 pH units higher and 57.1 °T lower than that of L. helveticus SH2‐1. The acidification of L. helveticus sh2‐5–66 was further demonstrated to be genetically stable during 100 generations cultivation. Moreover, the milk fermented with L. helveticus sh2‐5–66 showed improvement in textural and rheological properties and flavor during storage which could be further improved by coculture with the commercial starter S. thermophilus st447.
Questioning the role of amygdala and insula in an attentional capture by emotional stimuli task
Authors: Marxen Michael , Jacob Mark J. , Hellrung Lydia , Riedel Philipp , Smolka Michael N. 
Published: November 2020

AbstractOur senses are constantly monitoring the environment for emotionally salient stimuli that are potentially relevant for survival. Because of our limited cognitive resources, emotionally salient distractors prolong reaction times (RTs) as compared to neutral distractors. In addition, many studies have reported fMRI blood oxygen level‐dependent (BOLD) activation of both the amygdala and the anterior insula for similar valence contrasts. However, a direct correlation of trail‐by‐trial BOLD activity with RTs has not been shown, yet, which would be a crucial piece of evidence to relate the two observations. To investigate the role of the above two regions in the context of emotional distractor effects, we study here the correlation between BOLD activity and RTs for a simple attentional capture by emotional stimuli (ACES) choice reaction time task using a general linear subject‐level model with a parametric RT regressor. We found significant regression coefficients in the anterior insula, supplementary motor cortex, medial precentral regions, sensory‐motor areas and others, but not in the amygdala, despite activation of both insula and amygdala in the traditional valence contrast across trials (i.e., negative vs. neutral pictures). In addition, we found that subjects that exhibit a stronger RT distractor effect across trials also show a stronger BOLD valence contrast in the right anterior insula but not in the amygdala. Our results indicate that the current neuroimaging‐based evidence for the involvement of the amygdala in RT slowing is limited. We advocate that models of emotional capture should incorporate both the amygdala and the anterior insula as separate entities.
Examining the relationship between unconventional monetary policy and exchange rate movements: Empirical evidence from United States quantitative easing
Authors: Masoud Serag , Bein Murad A. , Khalifa Wagdi 
Published: November 2020

AbstractThis study employs Autoregressive Integrated Moving Average (ARIMA) and Autoregressive Conditional Heteroskedasctic (ARCH) models to examine the impact of the unconventional monetary policies implemented in the United States upon the exchange rate movement and volatility in the emerging and growth‐leading economies (EAGLEs), which include Brazil, India, Indonesia, Mexico, Philippines and Turkey. Two series of exchange rates, namely average exchange rate (AER) and end‐of‐period exchange rate (EER), are used with different sets of sample, EER covers 1990:01 to 2018:04 and AER spans over 1980:01 to 2018:04 period. The variance series of the ARCH model is used to measure the volatility of AER and EER. The best ARIMA model is estimated for AER and EER for each country, and the ARIMA model serves as the mean equation for the ARCH volatility measure. Unlike the previous studies, this paper focuses on the EAGLEs, employs exchange rate, and considers various ARCH alternatives in choosing the best model. The findings of the study reveal that India is the only country among the EAGLEs whose exchange rate movement is affected by the U.S. unconventional monetary policy. Another important point is the negative effect of QE policies on the volatility of both AER and EER across the EAGLEs countries. The implication is that QE policies tend to reduce the uncertainty in the foreign exchange of the EAGLEs countries. Hence the policy makers in the EAGLEs countries do not need to take any action whenever the United States pursues unconventional monetary policy.
Community and school violence as significant risk factors for school climate and bonding of teachers in Chile: A national hierarchical multilevel analysis
Authors: Varela Jorge J. , Melipillán Roberto , González Constanza , Letelier Pablo , Massis María Camila , Wash Nicole 
Published: November 2020

AbstractCommunity and school violence involve aggressive behaviors among youth and adults. Researchers have focused mostly on aggression among students without considering teachers as victims of violence. The study's purpose was to examine the consequences of community violence, school violence, and school climate on the levels of teacher's bonding to the school. We examined data of 5733 teachers from 510 schools in 68 different communities in Chile. We used Hierarchical Linear Modeling to examine the relationship between the individual, school, and community‐level variables. We found direct associations with school bonding at the individual level for victim school violence, school climate, size and type of school, and violence in the community at the community level. Our results highlight the importance of school violence prevention from a comprehensive perspective, starting at the community level, followed by the school to provide more teacher's support.