bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mass transfer study of butachlor biodegradation using immobilized microbial consortium SMC1 in a packed bed bioreactor
Authors: Mohanty Satya Sundar , Reddy D. Karthik , Jena Hara Mohan 
Published: March 2021

AbstractIn the present study, the effect of external mass transfer on the rate of butachlor biodegradation was studied using calcium alginate immobilized microbial consortium SMC1 in a re‐circulated up‐flow packed bed bioreactor in a batch scale. By assuming the biodegradation kinetics to be first order, the effect of various operational parameters such as feed flow rate, substrate concentration, and the external mass transfer on the bio‐removal of butachlor from the aqueous medium has been explored. Using external film diffusion models and Colburn analogy, the mass transfer correlations at several feed rates were worked out. The correlational analysis obtained in the form of JD = 1.341 was found to predict the experimental data precisely.
Global sensitivity analysis for assessing the parameters importance and setting a stopping criterion in a biomedical inverse problem
Authors: Rapadamnaba Robert , Ribatet Mathieu , Mohammadi Bijan 
Published: March 2021

AbstractThis paper shows how to obtain in addition to the standard deviations available after a data assimilation procedure based on the ensemble Kalman filter, an apportioning of the total uncertainty in the outputs of a patient‐specific blood flow model into small portions of uncertainty due to input parameters. Statistical indicators generally used for identifying the importance of numerical parameters, namely the Sobol' first order and total indices, are introduced and discussed. These allow the identification of the importance rank of the different input parameters for the patient‐specific blood flow model, as well as the influence of the interactions between these parameters on the model output variance. The results show that knowing the importance rank of the model input parameters during the assimilation procedure is useful to avoid unnecessary over‐solving and to find a suitable stopping criterion in clinical situations where faster diagnosis is always requested. Indeed, the work permits to reduce typically by a factor of six the time to solution and most importantly with very limited extra calculation using already available information.
BMP/TGF‐β signaling as a modulator of neurodegeneration in ALS
Authors: Russo Kathryn , Wharton Kristi A. 
Published: March 2021

AbstractThis commentary focuses on the emerging intersection between BMP/TGF‐β signaling roles in nervous system function and the amyotrophic lateral sclerosis (ALS) disease state. Future research is critical to elucidate the molecular underpinnings of this intersection of the cellular processes disrupted in ALS and those influenced by BMP/TGF‐β signaling, including synapse structure, neurotransmission, plasticity, and neuroinflammation. Such knowledge promises to inform us of ideal entry points for the targeted modulation of dysfunctional cellular processes in an effort to abrogate ALS pathologies. It is likely that different interventions are required, either at discrete points in disease progression, or across multiple dysfunctional processes which together lead to motor neuron degeneration and death. We discuss the challenging, but intriguing idea that modulation of the pleiotropic nature of BMP/TGF‐β signaling could be advantageous, as a way to simultaneously treat defects in more than one cell process across different forms of ALS.
Developing a flexible learning activity on biodiversity and spatial scale concepts using open‐access vegetation datasets from the National Ecological Observatory Network
Authors: Styers Diane M. , Schafer Jennifer L. , Kolozsvary Mary Beth , Brubaker Kristen M. , Scanga Sara E. , Anderson Laurel J. , Mitchell Jessica J. , Barnett David 
Published: March 2021

AbstractBiodiversity is a complex, yet essential, concept for undergraduate students in ecology and other natural sciences to grasp. As beginner scientists, students must learn to recognize, describe, and interpret patterns of biodiversity across various spatial scales and understand their relationships with ecological processes and human influences. It is also increasingly important for undergraduate programs in ecology and related disciplines to provide students with experiences working with large ecological datasets to develop students’ data science skills and their ability to consider how ecological processes that operate at broader spatial scales (macroscale) affect local ecosystems. To support the goals of improving student understanding of macroscale ecology and biodiversity at multiple spatial scales, we formed an interdisciplinary team that included grant personnel, scientists, and faculty from ecology and spatial sciences to design a flexible learning activity to teach macroscale biodiversity concepts using large datasets from the National Ecological Observatory Network (NEON). We piloted this learning activity in six courses enrolling a total of 109 students, ranging from midlevel ecology and GIS/remote sensing courses, to upper‐level conservation biology. Using our classroom experiences and a pre/postassessment framework, we evaluated whether our learning activity resulted in increased student understanding of macroscale ecology and biodiversity concepts and increased familiarity with analysis techniques, software programs, and large spatio‐ecological datasets. Overall, results suggest that our learning activity improved student understanding of biological diversity, biodiversity metrics, and patterns of biodiversity across several spatial scales. Participating faculty reflected on what went well and what would benefit from changes, and we offer suggestions for implementation of the learning activity based on this feedback. This learning activity introduced students to macroscale ecology and built student skills in working with big data (i.e., large datasets) and performing basic quantitative analyses, skills that are essential for the next generation of ecologists.
Recolonizing carnivores: Is cougar predation behaviorally mediated by bears?
Authors: Engebretsen Kristin N. , Beckmann Jon P. , Lackey Carl W. , Andreasen Alyson , Schroeder Cody , Jackson Pat , Young Julie K. 
Published: March 2021

AbstractConservation and management efforts have resulted in population increases and range expansions for some apex predators, potentially changing trophic cascades and foraging behavior. Changes in sympatric carnivore and dominant scavenger populations provide opportunities to assess how carnivores affect one another. Cougars (Puma concolor) were the apex predator in the Great Basin of Nevada, USA, for over 80 years. Black bears (Ursus americanus) have recently recolonized the area and are known to heavily scavenge on cougar kills. To evaluate the impacts of sympatric, recolonizing bears on cougar foraging behavior in the Great Basin, we investigated kill sites of 31 cougars between 2009 and 2017 across a range of bear densities. We modeled the variation in feeding bout duration (number of nights spent feeding on a prey item) and the proportion of primary prey, mule deer (Odocoileus hemionus), in cougar diets using mixed‐effects models. We found that feeding bout duration was driven primarily by the size of the prey item being consumed, local bear density, and the presence of dependent kittens. The proportion of mule deer in cougar diet across all study areas declined over time, was lower for male cougars, increased with the presence of dependent kittens, and increased with higher bear densities. In sites with feral horses (Equus ferus), a novel large prey, cougar consumption of feral horses increased over time. Our results suggest that higher bear densities over time may reduce cougar feeding bout durations and influence the prey selection trade‐off for cougars when alternative, but more dangerous, large prey are available. Shifts in foraging behavior in multicarnivore systems can have cascading effects on prey selection. This study highlights the importance of measuring the impacts of sympatric apex predators and dominant scavengers on a shared resource base, providing a foundation for monitoring dynamic multipredator/scavenger systems.
Tolerance niche expansion and potential distribution prediction during Asian openbill bird range expansion
Authors: Lei Yu , Liu Qiang 
Published: March 2021

AbstractIt is prevalent to use ecological niche models in the analysis of species expansion and niche changes. However, it is difficult to estimate the niche when alien species fail to establish in exotic areas. Here, we applied the tolerance niche concept, which means that niche of species can live and grow but preclude a species from establishing self‐sustaining populations, in such fail‐to‐establish events. Taking the rapidly expanded bird, Asian openbill (Anastomus oscitans), as a model species, we investigated niche dynamics and its potential effects on the population by Niche A and ecospat, predicted potential distribution by biomod2. Results showed that niche expansion has occurred in two non‐native populations caused by the tolerance of colder and wetter environments, and potential distribution mainly concentrated on equatorial islands. Our study suggested that the expanded niche belongs to tolerance niche concept according to the populations' dynamics and GPS tracking evidence. It is essential to consider source populations when we analyze the alien species. We recommended more consideration to the application of tolerance niche in alien species research, and there is still a need for standard measurement frameworks for analyzing the tolerance niche.
Higher temperatures increase growth rates of Rocky Mountain montane tree seedlings
Authors: Carroll Charles J.W. , Knapp Alan K. , Martin Patrick H. 
Published: March 2021

AbstractRecent observational studies report weak or flat temperature − growth relationships for many tree species in temperate forests. In contrast, distribution limits of trees are strongly shaped by temperature, and studies show marked short‐term temperature effects on leaf‐level ecophysiology. To better determine the effects of warming on trees, we planted one‐year‐old seedlings of one lower montane (ponderosa pine), two upper montane (quaking aspen and lodgepole pine), and one subalpine tree species (subalpine fir) in in situ experimental gardens on an elevation gradient in the Rocky Mountains (USA) which span a 6°C range in temperature but have approximately uniform precipitation. Seedlings were lightly watered the first three growing seasons to facilitate establishment, and growth and survivorship were followed for four years. We expected a trade‐off between growth and survivorship, as seedlings in high temperatures grow faster (e.g., with a longer growing season), but have higher mortality from heat stress. Compared to the coldest site, aspen (+256% wider, +337% taller), ponderosa pine (+234% wider, 270% taller), and lodgepole pine (+235% wider, 283% taller) all had strikingly higher cumulative diameter and height growth in the warmest site by the end of the study. Linear models of cumulative and annual growth in the montane species showed strong, positive relationships with growing‐season temperature, but no significant relationships with growing‐season precipitation. In contrast, growth of subalpine fir did not vary significantly with temperature, but increased slightly with higher growing‐season precipitation. Accelerated growth did not come at the expense of survivorship in the montane species: cumulative four‐year survivorship of the montane species remained robust (71.4–94.4%) in high temperatures, but caused complete mortality of subalpine fir. As long as precipitation remains adequate, these results indicate that warming is likely to strongly increase growth in seedlings of montane species with only modest decreases in survivorship despite higher evapotranspiration, especially in cooler and wetter portions of their current distributions where hydric stress is low. In contrast, warming may negatively affect seedling growth and survival in hotter and drier areas of the Rockies, and warming of +3–6°C may endanger the persistence of subalpine fir over much of its current distribution.
Absence of Non‐Linear Effects Despite Evidence for Catalyst Aggregation
Authors: Geiger Yannick , Achard Thierry , Maisse‐François Aline , Bellemin‐Laponnaz Stéphane 
Published: March 2021

AbstractAn in‐depth study of the catalytic system, consisting of the enantioselective addition of ZnEt2 to benzaldehyde with (1R,2S)‐(−)‐N‐Methylephedrine (NME) as chiral ligand, suggests the presence of dimeric and trimeric aggregates, as deduced from product ee vs. catalyst loading and NMR investigations (1H, DOSY). Formation of catalyst aggregation was excluded in earlier studies as this system displays a linear product ee vs. ligand ee‐correlation, which is usually taken as an indication for the absence of catalyst aggregation. A subsequent theoretical study, using the monomer‐dimer competition model, which we have recently developed, highlights the possible parameter configurations leading to linear product ee vs. ligand ee plots – despite the presence of catalyst dimers. It shows that, while the Kagan and Noyori models allow linearity in very specific cases only, a multitude of scenarios may lead to linearity here, especially if heterochiral dimers are catalytically active.
Estimating determinants of healthcare establishment locations with restricted federal administrative data
Authors: Van Sandt Anders , Carpenter Craig Wesley , Dudensing Rebekka , Loveridge Scott 
Published: March 2021

AbstractWe model the locational determinants of nine categories of healthcare services in the contiguous United States using restricted access federal establishment data. These data enable close examination of rural health services, which are subject to suppression in publicly published data sources. After reviewing differences in public and unsuppressed restricted data and testing underlying data generation processes for each healthcare industry, including the Poisson, negative binomial, and their zero‐inflated counterparts, we estimate marginal effects for four categories of independent variables: place‐based factors, financial access, characteristics of population, and industry interdependencies. Findings show establishments are less likely to be found with high concentrations of Medicare and Medicaid recipients, while agglomerations are associated with more establishments. Nonemployer establishments serve a broader spectrum of people, but the rural poor still experience less access to health care.
Neurons including hippocampal spatial view cells, and navigation in primates including humans
Authors: Rolls Edmund T. 
Published: March 2021

AbstractA new theory is proposed of mechanisms of navigation in primates including humans in which spatial view cells found in the primate hippocampus and parahippocampal gyrus are used to guide the individual from landmark to landmark. The navigation involves approach to each landmark in turn (taxis), using spatial view cells to identify the next landmark in the sequence, and does not require a topological map. Two other cell types found in primates, whole body motion cells, and head direction cells, can be utilized in the spatial view cell navigational mechanism, but are not essential. If the landmarks become obscured, then the spatial view representations can be updated by self‐motion (idiothetic) path integration using spatial coordinate transform mechanisms in the primate dorsal visual system to transform from egocentric to allocentric spatial view coordinates. A continuous attractor network or time cells or working memory is used in this approach to navigation to encode and recall the spatial view sequences involved. I also propose how navigation can be performed using a further type of neuron found in primates, allocentric‐bearing‐to‐a‐landmark neurons, in which changes of direction are made when a landmark reaches a particular allocentric bearing. This is useful if a landmark cannot be approached. The theories are made explicit in models of navigation, which are then illustrated by computer simulations. These types of navigation are contrasted with triangulation, which requires a topological map. It is proposed that the first strategy utilizing spatial view cells is used frequently in humans, and is relatively simple because primates have spatial view neurons that respond allocentrically to locations in spatial scenes. An advantage of this approach to navigation is that hippocampal spatial view neurons are also useful for episodic memory, and for imagery.
Colouring problems for symmetric configurations with block size 3
Authors: Erskine Grahame , Griggs Terry , Širáň Jozef 
Published: March 2021

AbstractThe study of symmetric configurations with block size 3 has a long and rich history. In this paper we consider two colouring problems which arise naturally in the study of these structures. The first of these is weak colouring, in which no block is monochromatic; the second is strong colouring, in which every block is multichromatic. The former has been studied before in relation to blocking sets. Results are proved on the possible sizes of blocking sets and we begin the investigation of strong colourings. We also show that the known and configurations without a blocking set are unique and make a complete enumeration of all nonisomorphic configurations. We discuss the concept of connectivity in relation to symmetric configurations and complete the determination of the spectrum of 2‐connected symmetric configurations without a blocking set. A number of open problems are presented.
Altered expression of serum miR‐106a, miR‐19b, miR‐17, and PTEN in patients with idiopathic membranous nephropathy
Authors: Wu Lina , Zhang Xinpeng , Luo Lin , Li Xiaoying , Liu Yong , Qin Xiaosong 
Published: March 2021

AbstractBackgroundTo find new diagnostic markers for idiopathic membranous nephropathy (IMN) and also conduct preliminary explorations into the possible pathogenesis of IMN by comparing the expression of microRNA‐451a (miR‐451a), miR‐106a, miR‐19b, miR‐17, and phosphatase and tensin homolog (PTEN) protein in the serum of patients with IMN and healthy controls.MethodsThe expression levels of miR‐451a, miR‐106a, miR‐19b, and miR‐17 in the serum of patients in the IMN group (n = 55, age: 50.2 ± 12.1 years) and the control group (n = 58, age 47.4 ± 13.1 years) were measured by quantitative real‐time polymerase chain reaction (qRT‐PCR), and the concentration of serum PTEN protein was determined by enzyme‐linked immunosorbent assay (ELISA).ResultsCompared with the control group, the expression of miR‐106a, miR‐19b, and miR‐17 was decreased significantly in the IMN group, whereas PTEN protein concentration was increased significantly in the IMN group. The areas under the receiver operating characteristic curve (AUC) of serum miR‐106a, miR‐19b, miR‐17, and PTEN were 0.66 (95% confidence interval [CI], 0.56–0.76), 0.81 (95% CI, 0.73–0.89), 0.69 (95% CI, 0.59–0.79), and 0.86 (95% CI, 0.79–0.93), respectively. The level of serum PTEN protein was negatively correlated with the expression of miR‐106a and miR‐19b. PTEN concentration was positively correlated with serum urea (Urea), creatinine (Crea), cystatin C (Cysc), 24 h urine total protein (24 h‐UP) and negatively correlated with albumin (Alb) and estimated glomerular filtration rate (eGFR).ConclusionsMiR‐106a, miR‐19b, miR‐17, and PTEN are involved in the pathogenesis of IMN and may become new biomarkers for the diagnosis of IMN.
Magnetic resonance imaging findings of the posterior fossa in 47 patients with mucopolysaccharidoses: A cross‐sectional analysis
Authors: Reichert Roberta , Pérez Juliano A. , Dalla‐Corte Amauri , Pinto e Vairo Filippo , de Souza Carolina F. M. , Giugliani Roberto , Isolan Gustavo R. , Stefani Marco Antonio 
Published: March 2021

AbstractBackgroundMucopolysaccharidoses (MPS) is a group of hereditary multisystemic lysosomal disorders. Most neuroimaging studies in MPS have focused on the supratentorial compartment and craniocervical junction abnormalities, and data regarding posterior fossa findings are scarce in the literature. Thus, our purpose is to describe posterior fossa findings on magnetic resonance imaging (MRI) of MPS patients.MethodsWe reviewed routine MRI scans of MPS patients being followed up at our institution (types I, II, III, IV, and VI), focusing on posterior fossa structures.ResultsForty‐seven MPS patients were included. MRI‐visible perivascular spaces were commonly found in the midbrain and adjacent to the dentate nuclei (85% and 55% of patients, respectively). White‐matter lesion was not identified in most cases. Its most frequent localizations were in the pons and cerebellum (34% and 30% of patients, respectively). Enlargement of cerebrospinal fluid (CSF) spaces in the posterior fossa was present in 55% of individuals and was more frequent in neuronopathic patients (73% vs 40%; P = .02). Cerebellar volume was classified as normal, apparent macrocerebellum, atrophic, and hypoplastic in 38%, 38%, 21%, and 3% of patients, respectively. A depression of the posterior fossa floor in the midline sagittal plane was found in 22 patients (47%), which was statistical significantly associated with enlargement of CSF spaces (P = .02) and with apparent macrocerebellum (P = .03).ConclusionThe present study compiled the main posterior fossa findings in MPS patients. Classically described in the supratentorial compartment, MRI‐visible perivascular spaces, white matter lesions, and enlarged perivascular spaces were also found in the posterior fossa. However, atrophy, which commonly affects cerebral hemispheres, was not the most frequent cerebellar morphology found in our study. Moreover, potential findings for future research were described.