bluuebunny/crossref_metadata_2025_split huggingface dataset:
Competence-based learning in engineering mechanics in an adaptive online learning environment
Authors: Linke Markus , Landenfeld Karin 
Published: August 2019

Abstract
In engineering sciences like mechanical or automotive engineering, pre-knowledge in mathematics is required to follow deeply specific engineering lectures. Mathematical skills are essential preconditions to successfully complete engineering lectures. It is necessary that these preconditions are identified for each individual student so that suitable learning opportunities can be provided according to the individual student needs. Within this paper an approach of competence-based learning in engineering mechanics is presented. This approach is assisted by an online learning environment that is adapted and extended by several features in order to enable a competence-oriented learning strategy. Computer-assisted tests are used for measuring mathematical pre-knowledge and pre-skills. Moreover, a mastery learning approach based on exercises is utilized in order to secure a certain skill level before students move forward to learn subsequent competencies. Test results influence the individual learning path by offering different learning elements to each student.
Polybrominated Diphenylether (DE-71) Exposure Skews Phenotypic Sex Ratio, and Alters Steroid Hormone Levels and Steroidogenic Enzyme Activities in Juvenile Silurana tropicalis
Authors: Fort Douglas J , Mathis Michael , Fort Chelsea , Fort Troy D , Guiney Patrick D , Weeks John A 
Published: August 2019

Abstract
The impact of the brominated flame-retardant mixture, DE-71, on gonadal steroidogenesis during sexual differentiation in Silurana tropicalis was examined. A partial lifecycle study exposing S. tropicalis to varying concentrations of DE-71 (0.0, 0.65, 1.3, 2.5, and 5.0 μg/l [nominal]) was conducted from early gastrula-stage embryo to 150 days postmetamorphosis (dpm). Exposure of S. tropicalis to DE-71 induced liver necrosis and induced abnormal ovary development characterized by previtellogenic oocyte necrosis and arrested development of vitellogenic oocytes in females in a concentration-dependent manner. Decreased mean plasma dihydrotestosterone (DHT) and T, gonad T, and increased mean plasma E2 levels were found in 150 dpm DE-71-treated male S. tropicalis compared to controls. Plasma E2 levels in females were not significantly altered compared to control S. tropicalis, although lower plasma and gonad T were detected. Mean gonadal CYP 19 aromatase activity in both male and female S. tropicalis exposed to DE-71 was not appreciably affected. Decreased mean male 5α-reductase and CYP17 activities in both male and females were observed compared to control frogs. Overall, these studies suggested that PBDE exposure induced liver necrosis and abnormal ovary development; and reduced circulating and gonadal androgens resulting in a phenotypic skew in sex ratio toward the female sex in S. tropicalis.
Phylogenetic analysis and revision of the strangest lace bug subfamily Vianaidinae (Heteroptera: Tingidae)
Authors: Guidoti Marcus , Montemayor Sara Itzel , Campos Luiz Alexandre , Guilbert Eric 
Published: August 2019

AbstractIn this study, we present a taxonomic review of a rarely collected subfamily of lace bugs (Vianaidinae: Tingidae: Heteroptera), including the description of nine new species and one new genus, and a phylogenetic analysis targeting its internal relationships. Anommatocoris araguanus sp. nov., A. knudsoni sp. nov., A. schuhi sp. nov., A. serratus sp. nov., A. sucreanus sp. nov., Thaumamannia insolita sp. nov. and T. urucuana sp. nov. are proposed, in addition to the new genus Henryvianaida gen. nov. with its two macropterous species, H. colombiensis sp. nov. and H. machupicchuensis sp. nov. The monophyly of all vianaidine genera is recovered and their synapomorphies are highlighted. Comments on fossil forms and insights on the future of Vianaidinae taxonomy and systematics are also included.
Investigating the attitudes of Canadian paramedic students towards homelessness
Authors: Cochrane Alyson , Pithia Priya , Laird Emma , Mifflin Kelly , Sonley-Long Venessa , Batt Alan M. 
Published: August 2019

AbstractIntroductionWhen paramedics are dispatched, it is expected that every patient receives the same level of care regardless of variable factors. Homelessness is a growing social issue across Canada that is particularly prevalent in urban areas. The quality of healthcare delivered to individuals experiencing homelessness may be influenced by negative attitudes held by healthcare professionals. There is an absence of literature quantifying the perspectives of paramedics towards homelessness; therefore, the focus of this study was to identify the attitudes of paramedic students towards homelessness and to continue the conversation in regards to the evolving educational needs of paramedic students.MethodsThis study employed a longitudinal design of a convenience sample of first year paramedic students in a college program in Ontario, Canada. The ‘Health Professional’s Attitude Towards the Homeless Inventory’ (HPATHI) was distributed to participants before and after placement and clinical exposure. The questionnaire includes 19 statements which participants respond to on a Likert scale. Mean scores were calculated, and statements were categorized into attitudes, interest, and confidence. Data were collected post-placement on interactions with persons experiencing homelessness.ResultsA total of 52 first year paramedic students completed the HPATHI pre-placement and 47 completed the questionnaire post-placement. Mean scores for attitudes (pre 3.64, SD 0.49; post 3.85, SD 0.38, p=0.032), interest (pre 3.91, SD 0.40; post 3.84, SD 0.39,p=0.51) and confidence (pre 4.02, SD 0.50; post 3.71, SD 0.67, p=0.004) were largely positive, but there was a demonstrated decreasing trend in confidence with, and interest in, working with those experiencing homelessness. Participants reported an average of 60 hours of placement, during which 15 participants (32%) reported interactions with people experiencing homelessness.ConclusionFirst year paramedic students demonstrate overall positive attitudes towards those experiencing homelessness, and the mean score for attitudes improved over the surveys. However, there were demonstrable decreases in confidence and interest over time, which may be related to the type and frequency of interactions during clinical placement. Paramedic education programs may benefit from the inclusion of focused education on homelessness, specific clinical experiences, and education related to social determinants of health.
Direct Binding of Phosphatidylglycerol at Specific Sites Modulates Desensitization of a Pentameric Ligand-Gated Ion Channel
Authors: Tong Ailing , Petroff John T. , Hsu Fong-Fu , Schmidpeter Philipp A. M. , Nimigean Crina M. , Sharp Liam , Brannigan Grace , Cheng Wayland W. L. 
Published: August 2019

AbstractPentameric ligand-gated ion channels (pLGICs) are essential determinants of synaptic transmission, and are modulated by specific lipids including anionic phospholipids. The exact modulatory effect of anionic phospholipids in pLGICs and the mechanism of this effect are not well understood. Using native mass spectrometry, coarse-grained molecular dynamics simulations and functional assays, we show that the anionic phospholipid, 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG), preferentially binds to and stabilizes the pLGIC, Erwinia ligand-gated ion channel (ELIC), and decreases ELIC desensitization. Mutations of five arginines located in the interfacial regions of the transmembrane domain (TMD) reduce POPG binding, and a subset of these mutations increase ELIC desensitization. In contrast, the L240A mutant known to decrease ELIC desensitization, increases POPG binding. The results support a mechanism by which POPG stabilizes the open state of ELIC relative to the desensitized state by direct binding at specific sites.
Tau Accumulation via Reduced BAG3-mediated Autophagy Is Required for GGGGCC Repeat Expansion-Induced Neurodegeneration
Authors: Wen Xue , An Ping , Li Hexuan , Zhou Zijian , Sun Yimin , Wang Jian , Ma Lixiang , Lu Boxun 
Published: August 2019

SUMMARYExpansions of trinucleotide or hexanucleotide repeats lead to several neurodegenerative disorders including Huntington disease (HD, caused by the expanded CAG repeats (CAGr) in the HTT gene) and amyotrophic lateral sclerosis (ALS, could be caused by the expanded GGGGCC repeats (G4C2r) in the C9ORF72 gene), of which the molecular mechanisms remain unclear. Here we demonstrate that loss of the Drosophila orthologue of tau protein (dtau) significantly rescued in vivo neurodegeneration, motor performance impairments, and shortened life-span in Drosophila models expressing mutant HTT protein with expanded CAGr or the expanded G4C2r. Importantly, expression of human tau (htau4R) restored the disease-relevant phenotypes that were mitigated by the loss of dtau, suggesting a conserved role of tau in neurodegeneration. We further discovered that G4C2r expression increased dtau accumulation, possibly due to reduced activity of BAG3-mediated autophagy. Our study reveals a conserved role of tau in G4C2r-induced neurotoxicity in Drosophila models, providing mechanistic insights and potential therapeutic targets.
Early-life adversity is associated with differential gene expression in response to acute psychological stress: preliminary findings
Authors: Shalev Idan , Hastings Waylon J. , Etzel Laura , Israel Salomon , Russell Michael A. , Hendrick Kelsie A. , Zinobile Megan , Siegel Sue Rutherford 
Published: August 2019

AbstractObjectiveExposure to early-life adversity (ELA) can result in long-term changes to physiological systems, which predispose individuals to negative health outcomes. This biological embedding of stress-responsive systems may operate via dysregulation of physiological resources in response to common stressors. The present study used a novel experimental design to test how young adults’ exposure to ELA influence neuroendocrine and inflammatory responses to acute stress.Materials and methodsParticipants were 12 males (mean age= 21.25), half of whom endorsed at least three significant adverse events up to age 18 years (‘ELA group’), and half who confirmed zero (‘controls’). Using a randomized within-subjects, between-groups experimental design, we induced acute psychosocial stress (Trier Social Stress Test, TSST), and included a no-stress control condition one week apart. During these sessions, we obtained repeated measurements of physiological reactivity, gene expression of NR3C1, FKBP5 and NFKB1, and plasma levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and TNFα) over a 4-hour window post-test.ResultsThe ELA group evinced significantly higher cortisol response and lower NR3C1 gene expression in response to the TSST compared with controls, while no differences were observed in the no-stress condition. Cortisol and group status interacted such that increase in cortisol predicted increase in both NR3C1 and NFKB1 expression among controls, but decrease in the ELA group. For pro-inflammatory cytokines, only IL-6 increased significantly in response to the TSST, with no differences between the two groups.ConclusionOverall, we provide preliminary findings for the biological embedding of stress via a dynamic and dysregulated pattern evidenced in response to acute psychosocial stress. ELA may program physiological systems in a maladaptive manner more likely to manifest during times of duress, predisposing individuals to the negative health consequences of everyday stressors. Future studies with larger sample size including both males and females are needed to replicate these findings.
Single-cell proteomics reveals downregulation of TMSB4X to drive actin release for stereocilia assembly
Authors: Zhu Ying , Scheibinger Mirko , Ellwanger Daniel C. , Krey Jocelyn F. , Choi Dongseok , Kelly Ryan T. , Heller Stefan , Barr-Gillespie Peter G. 
Published: August 2019

AbstractHearing and balance rely on small sensory hair cells that reside in the inner ear. To explore dynamic changes in the abundant proteins present in differentiating hair cells, we used nanoliter-scale shotgun mass spectrometry of single cells, each ∼1 picoliter, from utricles of embryonic day 15 chickens. We identified unique constellations of proteins or protein groups from presumptive hair cells and from progenitor cells. The single-cell proteomes enabled thede novoreconstruction of a developmental trajectory. Inference of protein expression dynamics revealed that the actin monomer binding protein thymosin β4 (TMSB4X) was present in progenitors but dropped precipitously during hair-cell differentiation. Complementary single-cell transcriptome profiling showed downregulation ofTMSB4XmRNA during maturation of hair cells. We propose that most actin is sequestered by TMSB4X in progenitor cells, but upon differentiation to hair cells, actin is released to build the sensory hair bundle.
PCR-based detection ofHelicobacterspp. in mice from different animal houses in Rio de Janeiro, Brazil
Authors: Matos-Rodrigues Gabriel E. , Masseron Carolinne C. , da Silva Fabio J. Moreira , Flajblat Marcel , Moreira Lilian O. , Martins Rodrigo A. P. 
Published: August 2019

AbstractPathogenic microbial detection and control in breeding and experimental laboratory animal facilities is essential to guarantee animal welfare, data validity and reproducibility.Helicobacter spp.is known to severely affect mice health, mainly in immunocompromised strains, what may affect experimental outcomes. This study aimed to screen forHelicobacter spp.in mice from four different animal houses in Rio de Janeiro, Brazil using a PCR for 16S ribosomal RNA. A pair of primers was designed to specifically identifyHelicobacterspecies that commonly infect laboratory mice. Following PCR reaction, the expected 375 base pairs (bp) amplification product was purified, sequenced and showed a 95% similarity when compared to deposited sequences ofHelicobacter hepaticusandHelicobacter bilis. Then, the presence ofHelicobacter spp.in both feces and intestines samples was analyzed.Helicobacter sppDNA was detected in 59.6% of the fecal and 70.17% of the intestine samples. AlthoughHelicobacter sppscreening is recommended by institutional animal health monitoring programs worldwide it is still not mandatory by Brazilian animal welfare regulation. Our study, the first to monitorHelicobacterspecies in laboratory mice in Brazil, demonstrates the possibility of using a low cost, rapid molecular diagnostic test to screenHelicobacterand highlights the importance of regular microbiological verification of mice used for research in Brazilian animal houses.
Mechanisms of Chromosomal Instability in High-grade Serous Ovarian Carcinoma
Authors: Tamura N. , Shaikh N. , Muliaditan D. , McGuinness J. , Moralli D. , Durin M. A. , Green C. M. , Bowtell D. , Balkwill F. R. , Curtius K. , McClelland S. E. 
Published: August 2019

AbstractChromosomal instability (CIN), the continual gain and loss of chromosomes or parts of chromosomes, occurs in the majority of cancers and confers poor prognosis. Mechanisms driving CIN remain unknown in most cancer types due to a scarcity of functional studies. High-grade serous ovarian carcinoma (HGSC), the most common subtype of ovarian cancer, is the major cause of death due to gynaecological malignancy in the Western world with chemotherapy resistance developing in almost all patients. HGSC exhibits high rates of chromosome aberrations and knowledge of causative mechanisms is likely to represent an important step towards combating the poor prognosis of this disease. However, very little is known about the nature of chromosomal instability exhibited by this cancer type in particular due to a historical lack of appropriate cell line models. Here we perform the first in-depth functional characterisation of mechanisms driving CIN in HGSC by analysing eight cell lines that accurately recapitulate HGSC genetics as defined by recent studies. We show, using a range of established functional CIN assays combined with live cell imaging and single molecule DNA fibre analysis, that multiple mechanisms co-exist to drive CIN in HGSC. These include supernumerary centrosomes, elevated microtubule dynamics and DNA replication stress. By contrast, the spindle assembly checkpoint was intact. These findings are relevant for developing therapeutic approaches to manipulating CIN in ovarian cancer, and suggests that such approaches may need to be multimodal to combat multiple co-existing CIN drivers.
Heating quinoa shoots results in yield loss by inhibiting fruit production and delaying maturity
Authors: Tovar Jose C. , Quillatupa Carlos , Callen Steven T. , Castillo S. Elizabeth , Pearson Paige , Shamin Anastasia , Schuhl Haley , Fahlgren Noah , Gehan Malia A. 
Published: August 2019

SummaryIncreasing global temperatures and a growing world population create the need to develop crop varieties that yield more in warmer climates. There is growing interest in expanding quinoa cultivation, because of quinoa’s ability to produce nutritious grain in poor soils, with little water and at high salinity. However, the main limitation to expanding quinoa cultivation is quinoa’s susceptibility to temperatures above ~32°C. This study investigates the phenotypes, genes, and mechanisms that may affect quinoa seed yield at high temperatures. By using a differential heating system where only roots or only shoots were heated, quinoa yield losses were attributed to shoot heating. Plants with heated shoots lost 60% to 85% yield as compared to control. Yield losses were due to lower fruit production, which lowered the number of seeds produced per plant. Further, plants with heated shoots had delayed maturity and more non-reproductive shoot biomass, while plants with both heated roots and heated shoots produced more yield from panicles that escaped heat than control. This suggests that quinoa uses a type of avoidance strategy to survive heat. Gene expression analysis identified transcription factors differentially expressed in plants with heated shoots and low yield that had been previously associated with flower development and flower opening. Interestingly, in plants with heated shoots, flowers stayed closed during the day while control flowers were open. Although a closed flower may protect floral structures, this could also cause yield losses by limiting pollen dispersal, which is necessary to produce fruit in quinoa’s mostly female flowers.Significance StatementThis study provides evidence that heating quinoa during flowering results in seed yield loss by lowering fruit production. Plants with low yield after heat treatment also matured more slowly, suggesting that quinoa may use a type of avoidance strategy to survive heat stress conditions. Genes differentially expressed under heat include genes involved in flower development and flower opening.
Cognitive ability, Socioeconomic Status, and Depressive Symptoms: A Gene-Environment-Trait Correlation
Authors: Avinun Reut 
Published: August 2019

AbstractPurposeDepression is genetically influenced, but the mechanisms that underlie these influences are largely unknown. Recently, shared genetic influences were found between depression and both cognitive ability and educational attainment (EA). Although genetic influences are often thought to represent direct biological pathways, they can also reflect indirect pathways, including modifiable environmental mediations (gene-environment-trait correlations). Here, I tested whether the genetic correlation between cognitive ability and depressive symptoms partly reflects an environmental mediation involving socioeconomic status (SES).MethodsAs previously done to increase statistical power, and due to their high phenotypic and genetic correlation, EA was used as a proxy for cognitive ability. Summary statistics from a recent genome-wide association study of EA were used to calculate EA polygenic scores. Two independent samples were used: 522 non-Hispanic Caucasian university students from the Duke Neurogenetics Study (277 women, mean age 19.78±1.24 years) and 5,243 white British volunteers (2,669 women, mean age 62.30±7.41 years) from the UK biobank.ResultsMediation analyses in the two samples indicated that higher proxy-cognitive ability polygenic scores predicted higher SES, which in turn predicted lower depressive symptoms.ConclusionCurrent findings suggest that some of the genetic correlates of depressive symptoms depend on an environmental mediation and consequently that modifying the environment, specifically through social and economic policies, can affect the genetic influences on depression. Additionally, these results suggest that findings from genetic association studies of depression may be context-contingent and reflect social, cultural, and economic processes in the examined population.
NeuroGPU: Accelerating multi-compartment, biophysically detailed neuron simulations on GPUs
Authors: Ben-Shalom Roy , Artherya Nikhil S. , Ladd Alexander , Cross Christopher , Sanghevi Hersh , Kim Kyung Geun , Korngreen Alon , Bouchard Kristofer E. , Bender Kevin J. 
Published: August 2019

AbstractThe membrane potential of individual neurons depends on a large number of interacting biophysical processes operating on spatial-temporal scales spanning several orders of magnitude. The multi-scale nature of these processes dictates that accurate prediction of membrane potentials in specific neurons requires utilization of detailed simulations. Unfortunately, constraining parameters within biologically detailed neuron models can be difficult, leading to poor model fits. This obstacle can be overcome partially by numerical optimization or detailed exploration of parameter space. However, these processes, which currently rely on central processing unit (CPU) computation, often incur exponential increases in computing time for marginal improvements in model behavior. As a result, model quality is often compromised to accommodate compute resources. Here, we present a simulation environment, NeuroGPU, that takes advantage of the inherent parallelized structure of graphics processing unit (GPU) to accelerate neuronal simulation. NeuroGPU can simulate most of biologically detailed models 800x faster than traditional simulators when using multiple GPU cores, and even 10-200 times faster when implemented on relatively inexpensive GPU systems. We demonstrate the power of NeuoGPU through large-scale parameter exploration to reveal the response landscape of a neuron. Finally, we accelerate numerical optimization of biophysically detailed neuron models to achieve highly accurate fitting of models to simulation and experimental data. Thus, NeuroGPU enables the rapid simulation of multi-compartment, biophysically detailed neuron models on commonly used computing systems accessible by many scientists.