bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen and Al‐Mg isotopic compositions of grossite‐bearing refractory inclusions from CO3 chondrites
Authors: Simon Steven B. , Krot Alexander N. , Nagashima Kazuhide 
Published: April 2019

AbstractThe distribution of the short‐lived radionuclide 26Al in the early solar system remains a major topic of investigation in planetary science. Thousands of analyses are now available but grossite‐bearing Ca‐, Al‐rich inclusions (CAIs) are underrepresented in the database. Recently found grossite‐bearing inclusions in CO3 chondrites provide an opportunity to address this matter. We determined the oxygen and magnesium isotopic compositions of individual phases of 10 grossite‐bearing CAIs in the Dominion Range (DOM) 08006 (CO3.0) and DOM 08004 (CO3.1) chondrites. All minerals in DOM 08006 CAIs as well as hibonite, spinel, and pyroxene in DOM 08004 are uniformly 16O‐rich (Δ17O = −25 to −20‰) but grossite and melilite in DOM 08004 CAIs are not; Δ17O of grossite and melilite range from ~ −11 to ~0‰ and from ~ −23 up to ~0‰, respectively. Even within this small suite, in the two chondrites a bimodal distribution of the inferred initial 26Al/27Al ratios (26Al/27Al)0 is seen, with four having (26Al/27Al)0 ≤1.1 × 10−5 and six having (26Al/27Al)0 ≥3.7 × 10−5. Five of the 26Al‐rich CAIs have (26Al/27Al)0 within error of 4.5 × 10−5; these values can probably be considered indistinguishable from the “canonical” value of 5.2 × 10−5 given the uncertainty in the relative sensitivity factor for grossite measured by secondary ion mass spectrometry. We infer that the 26Al‐poor CAIs probably formed before the radionuclide was fully mixed into the solar nebula. All minerals in the DOM 08006 CAIs, as well as spinel, hibonite, and Al‐diopside in the DOM 08004 CAIs retained their initial oxygen isotopic compositions, indicating homogeneity of oxygen isotopic compositions in the nebular region where the CO grossite‐bearing CAIs originated. Oxygen isotopic heterogeneity in CAIs from DOM 08004 resulted from exchange between the initially 16O‐rich (Δ17O ~−24‰) melilite and grossite and 16O‐poor (Δ17O ~0‰) fluid during hydrothermal alteration on the CO chondrite parent body; hibonite, spinel, and Al‐diopside avoided oxygen isotopic exchange during the alteration. Grossite and melilite that underwent oxygen isotopic exchange avoided redistribution of radiogenic 26Mg and preserved undisturbed internal Al‐Mg isochrons. The Δ17O of the fluid can be inferred from O‐isotopic compositions of aqueously formed fayalite and magnetite that precipitated from the fluid on the CO parent asteroid. This and previous studies suggest that O‐isotope exchange during fluid–rock interaction affected most CAIs in CO ≥3.1 chondrites.
Time series are critical to understand microbial plankton diversity and ecology
Authors: Moreira David , López‐García Purificación 
Published: April 2019

AbstractHow diverse are marine planktonic protist communities? How much seasonality do they exhibit? For a very long time, these two old and challenging questions in the field of plankton ecology could be addressed only for large‐size protist species, based on cell counting under the microscope. The recent application of molecular techniques, notably massive marker‐gene amplicon sequencing approaches (metabarcoding), has allowed investigating with unprecedented level of resolution the small‐sized (<20 µm) planktonic eukaryotes too. An amazing diversity of these tiny organisms has been unveiled but details about their temporal dynamics remain much more elusive. In a From the Cover article in this issue of Molecular Ecology, Giner et al. (2019) introduce a new Recurrence Index (RI) to specifically look for seasonality in time‐series metabarcoding data. They inspected the temporal dynamics of all operational taxonomic units (OTUs) in a rich sequence data set of pico‐ and nanoplanktonic eukaryotes in samples collected monthly during 10 years. Although most OTUs did not show seasonality, some abundant ones did, which explains why some averaging methods can find seasonality at the less detailed level of whole planktonic communities. Not surprisingly, the very complex small‐sized eukaryotic plankton communities are composed of organisms with miscellaneous temporal dynamics.
Spatiotemporally explicit demographic modelling supports a joint effect of historical barriers to dispersal and contemporary landscape composition on structuring genomic variation in a red‐listed grasshopper
Authors: González‐Serna María José , Cordero Pedro J. , Ortego Joaquín 
Published: April 2019

AbstractInferring the processes underlying spatial patterns of genomic variation is fundamental to understand how organisms interact with landscape heterogeneity and to identify the factors determining species distributional shifts. Here, we use genomic data (restriction site‐associated DNA sequencing) to test biologically informed models representing historical and contemporary demographic scenarios of population connectivity for the Iberian cross‐backed grasshopper Dociostaurus hispanicus, a species with a narrow distribution that currently forms highly fragmented populations. All models incorporated biological aspects of the focal taxon that could hypothetically impact its geographical patterns of genomic variation, including (a) spatial configuration of impassable barriers to dispersal defined by topographic landscapes not occupied by the species; (b) distributional shifts resulting from the interaction between the species bioclimatic envelope and Pleistocene glacial cycles; and (c) contemporary distribution of suitable habitats after extensive land clearing for agriculture. Spatiotemporally explicit simulations under different scenarios considering these aspects and statistical evaluation of competing models within an Approximate Bayesian Computation framework supported spatial configuration of topographic barriers to dispersal and human‐driven habitat fragmentation as the main factors explaining the geographical distribution of genomic variation in the species, with no apparent impact of hypothetical distributional shifts linked to Pleistocene climatic oscillations. Collectively, this study supports that both historical (i.e., topographic barriers) and contemporary (i.e., anthropogenic habitat fragmentation) aspects of landscape composition have shaped major axes of genomic variation in the studied species and emphasizes the potential of model‐based approaches to gain insights into the temporal scale at which different processes impact the demography of natural populations.
Cell‐cell communication, chemotaxis and recruitment in Vibrio parahaemolyticus
Authors: Lamb Evan , Trimble Michael J. , McCarter Linda L. 
Published: April 2019

SummaryMotile bacteria are proficient at finding optimal environments for colonization. Often, they use chemotaxis to sense nutrient availability and dangerous concentrations of toxic chemicals. For many bacteria, the repertoire of chemoreceptors is large, suggesting they possess a broad palate with respect to sensing. However, knowledge of the molecules detected by chemotaxis signal transduction systems is limited. Some bacteria, like Vibrio parahaemolyticus, are social and swarm in groups on surfaces. This marine bacterium and human pathogen secretes the S signal autoinducer, which cues degradation of intracellular c‐di‐GMP leading to transcription of the swarming program. Here, we report that the S signal also directs motility at a behavioral level by serving as a chemoattractant. The data demonstrate that V. parahaemolyticus senses the S signal using SscL and SscS, homologous methyl‐accepting chemotaxis proteins. SscL is required by planktonic bacteria for S signal chemotaxis. SscS plays a role during swarming, and mutants lacking this chemoreceptor swarm faster and produce colonies with more deeply branched swarming fronts than the wild type or the sscL mutant. Other Vibrio species can swim toward the S signal, suggesting a recruitment role for this cell‐cell communication molecule in the context of polymicrobial marine communities.
Nicotiana species as surrogate host for studying the pathogenicity of Acidovorax citrulli, the causal agent of bacterial fruit blotch of cucurbits
Authors: Traore Sy M. , Eckshtain‐Levi Noam , Miao Jiamin , Castro Sparks Anita , Wang Zhibo , Wang Kunru , Li Qi , Burdman Saul , Walcott Ron , Welbaum Gregory E. , Zhao Bingyu 
Published: April 2019

SummaryBacterial fruit blotch (BFB) caused by Acidovorax citrulli is one of the most important bacterial diseases of cucurbits worldwide. However, the mechanisms associated with A. citrulli pathogenicity and genetics of host resistance have not been extensively investigated. We idenitfied Nicotiana benthamiana and Nicotiana tabacum as surrogate hosts for studying A. citrulli pathogenicity and non‐host resistance triggered by type III secreted (T3S) effectors. Two A. citrulli strains, M6 and AAC00‐1, that represent the two major groups amongst A. citrulli populations, induced disease symptoms on N. benthamiana, but triggered a hypersensitive response (HR) on N. tabacum plants. Transient expression of 19 T3S effectors from A. citrulli in N. benthamiana leaves revealed that three effectors, Aave_1548, Aave_2708, and Aave_2166, trigger water‐soaking‐like cell death in N. benthamiana. Aave_1548 knockout mutants of M6 and AAC00‐1 displayed reduced virulence on N. benthamiana and melon (Cucumis melo L.). Transient expression of Aave_1548 and Aave_2166 effectors triggered a non‐host HR in N. tabacum, which was dependent on the functionality of the immune signalling component, NtSGT1. Hence, employing Nicotiana species as surrogate hosts for studying A. citrulli pathogenicity may help characterize the function of A. citrulli T3S effectors and facilitate the development of new strategies for BFB management.
The secessionist spectre: the influence of authoritarianism, nativism and populism on support for Quebec independence
Authors: Blanchet Alexandre , Medeiros Mike 
Published: April 2019

AbstractIn recent years, Quebec has been undergoing a re‐evaluation of immigration and integration policies. The secessionist Parti Québécois had become the leader of this debate, which also coincided with a rise of right‐wing nativist, populist and sometimes authoritarian movements in other Western societies. This paper aims to evaluate the similarity or dissimilarity of Quebec's nationalism to these other nationalisms. We use the 2015 Canadian Election Study data to explore the influence of authoritarianism, nativism and populism directly on support for secession and also, indirectly, on voting intentions. We find that authoritarianism has a negative influence on support for Quebec independence and independentist parties, while the pattern is the opposite, and the effects somewhat weaker, for nativism and populism. Hence, we argue that Quebec nationalism does not seem to correlate with the right‐wing populist movement extending throughout many Western societies. Thus, Quebec nationalism was shown to be a distinct form of nationalism.
Arrhythmogenic calmodulin E105A mutation alters cardiac RyR2 regulation leading to cardiac dysfunction in zebrafish
Authors: Da'as Sahar I. , Thanassoulas Angelos , Calver Brian L. , Beck Konrad , Salem Rola , Saleh Alaaeldin , Kontogianni Iris , Al‐Maraghi Ali , Nasrallah Gheyath K. , Safieh‐Garabedian Bared , Toft Egon , Nounesis George , Lai F. Anthony , Nomikos Michail 
Published: April 2019

AbstractCalmodulin (CaM) is a universal calcium (Ca2+)‐binding messenger that regulates many vital cellular events. In cardiac muscle, CaM associates with ryanodine receptor 2 (RyR2) and regulates excitation–contraction coupling. Mutations in human genes CALM1, CALM2, and CALM3 have been associated with life‐threatening heart disorders, such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia. A novel de novo LQTS‐associated missense CaM mutation (E105A) was recently identified in a 6‐year‐old boy, who experienced an aborted first episode of cardiac arrest. Herein, we report the first molecular characterization of the CaM E105A mutation. Expression of the CaM E105A mutant in zebrafish embryos resulted in cardiac arrhythmia and increased heart rate, suggestive of ventricular tachycardia. In vitro biophysical and biochemical analysis revealed that E105A confers a deleterious effect on protein stability and a reduced Ca2+‐binding affinity due to loss of cooperativity. Finally, the CaM E105A mutation resulted in reduced CaM–RyR2 interaction and defective modulation of ryanodine binding. Our findings suggest that the CaM E105A mutation dysregulates normal cardiac function by a complex mechanism involving alterations in both CaM–Ca2+ and CaM–RyR2 interactions.
Connecting pancreatic islet lipid metabolism with insulin secretion and the development of type 2 diabetes
Authors: Imai Yumi , Cousins Ryan S. , Liu Siming , Phelps Brian M. , Promes Joseph A. 
Published: April 2019

AbstractObesity is the major contributing factor for the increased prevalence of type 2 diabetes (T2D) in recent years. Sustained positive influx of lipids is considered to be a precipitating factor for beta cell dysfunction and serves as a connection between obesity and T2D. Importantly, fatty acids (FA), a key building block of lipids, are a double‐edged sword for beta cells. FA acutely increase glucose‐stimulated insulin secretion through cell‐surface receptor and intracellular pathways. However, chronic exposure to FA, combined with elevated glucose, impair the viability and function of beta cells in vitro and in animal models of obesity (glucolipotoxicity), providing an experimental basis for the propensity of beta cell demise under obesity in humans. To better understand the two‐sided relationship between lipids and beta cells, we present a current view of acute and chronic handling of lipids by beta cells and implications for beta cell function and health. We also discuss an emerging role for lipid droplets (LD) in the dynamic regulation of lipid metabolism in beta cells and insulin secretion, along with a potential role for LD under nutritional stress in beta cells, and incorporate recent advancement in the field of lipid droplet biology.
A review of the major threats and challenges to global bat conservation
Authors: Frick Winifred F. , Kingston Tigga , Flanders Jon 
Published: April 2019

AbstractBats are an ecologically and taxonomically diverse group accounting for roughly a fifth of mammalian diversity worldwide. Many of the threats bats face (e.g., habitat loss, bushmeat hunting, and climate change) reflect the conservation challenges of our era. However, compared to other mammals and birds, we know significantly less about the population status of most bat species, which makes prioritizing and planning conservation actions challenging. Over a third of bat species assessed by the International Union for Conservation of Nature (IUCN) are considered threatened or data deficient, and well over half of the species have unknown or decreasing population trends. That equals 988 species, or 80% of bats assessed by IUCN, needing conservation or research attention. Delivering conservation to bat species will require sustained efforts to assess population status and trends and address data deficiencies. Successful bat conservation must integrate research and conservation to identify stressors and their solutions and to test the efficacy of actions to stabilize or increase populations. Global and regional networks that connect researchers, conservation practitioners, and local stakeholders to share knowledge, build capacity, and prioritize and coordinate research and conservation efforts, are vital to ensuring sustainable bat populations worldwide.
Dental implants in individuals with osteogenesis imperfecta: a 6‐year follow‐up study
Authors: Myint M. , Støvne S.A. , Sæves R. , Bjørnland T. , Jensen J.L. 
Published: April 2019

AbstractAimThe aim of the present study was to follow‐up our previous prospective study that reported high implant survival in a group of Norwegian individuals with osteogenesis imperfecta. Our hypothesis was that implant treatment in these persons has approximately the same long‐term survival rate as in healthy individuals.Study groupThe previous study included seven participants (20 implants), four of them (11 implants) took part in the present study and the other three had died. The participants were followed up for an average of 93 months, subsequent to prosthetic loading. The implants were clinically and radiographically examined. Objective and subjective evaluations were recorded using an analogue scale ranging from 0 as the worst to 10 as the best score. A mean of these evaluations is presented as the subjective and objective overall satisfaction. In the previous study, no implants were lost and 1 mm bone loss was recorded around two implants. One implant was removed after 76 months due to an implant neck fracture. At the present study, four implants showed 1 mm bone loss, two of which had the same level of bone loss in the previous study. Four millimetre bone loss was observed around two other implants. No bone loss was detected around the remaining four implants. Objective and subjective evaluation of implant treatment showed an overall high satisfaction of 9.1 and 9.9 respectively.ConclusionThe findings showed an implant survival rate of 91% (100%, excluding the implant neck fracture) and high recipient satisfaction towards implant treatment.
Intention to care for gay and lesbian patients and knowledge about homosexuality: A comparison of Taiwanese nurses in 2005 and in 2017
Authors: Lin Yi‐Chun , Yen Cheng‐Fang , Wang Peng‐Wei , Huang Yu‐Te , Chen Yao‐Mei , Chuang Yu‐Hsien , Hu Huei‐Fan 
Published: April 2019

AbstractObjectiveTo examine the differences in the levels of intention to care for gay and lesbian patients and knowledge regarding homosexuality among Taiwanese nurses between 2005 and 2017 and the moderators of these differences.Design and SampleThis two‐wave survey study was conducted on nurses in 2005 (N = 1,176; Survey 2005) and 2017 (N = 1,519; Survey 2017) recruited from three hospitals.MeasurementsAn anonymous self‐report questionnaire was used.ResultsIn Survey 2017, the nurses expressed both a higher intention to care for gay and lesbian patients and degree of knowledge regarding homosexuality than did those in Survey 2005. The experience of providing care for gay or lesbian patients moderated the association between the time of the survey and intention to care for gay and lesbian patients. Moreover, having gay or lesbian friends or relatives moderated the association between the time of the survey and knowledge about homosexuality.ConclusionsNurses’ intention to care for gay and lesbian patients and knowledge regarding homosexuality in Taiwan significantly increased from 2005 to 2017. The experience of providing care for gay and lesbian patients and having gay or lesbian friends or relatives moderated the increase of nurses’ intention to care and knowledge.
Predictive model for Zika virus RNA minipool nucleic acid testing in outbreak scenarios
Authors: Yogurtcu Osman N. , Yang Hong , Chancey Caren , Forshee Richard A. , Eder Anne F. 
Published: April 2019

BACKGROUNDZika virus (ZIKV), a mosquito‐borne flavivirus, causes asymptomatic infections in blood donors and can be transmitted by transfusion. During the 2016 US outbreak, universal individual‐donation nucleic acid testing (ID‐NAT) was used to screen the blood supply for ZIKV. Testing pooled samples from multiple donations with minipool (MP)‐NAT is less sensitive than ID‐NAT, which raised questions about its utility in ZIKV outbreaks.STUDY DESIGN AND METHODSA mathematical model and computer simulation determined the risk of missing ID‐NAT–reactive and immunoglobulin (Ig) M–negative donations in a ZIKV outbreak if MP‐NAT is used initially instead of ID‐NAT. The model calculated the time required for ZIKV RNA to replicate to a concentration detectable by testing donations individually or in pools of 6 (MP6) or 16 (MP16). A computer simulation then randomly selected infection times to determine the probability of detection by the candidate tests.RESULTSThe probability of detecting the first ID‐NAT–reactive unit in an outbreak is 92% (2.5th‐97.5th percentile, 79%‐99%) by MP6 and 85% (2.5th‐97.5th percentile, 67%‐99%) by MP16. When one donation is detected by MP‐NAT, the model predicts that the chance of having missed one or more ID‐NAT–reactive donations is 8% to 15%. The probability of missing a unit by MP‐NAT is constant over the course of the outbreak (8% by MP6, 15% by MP16).CONCLUSIONThe model predicts that the probability that a candidate MP‐NAT will detect the first ID‐NAT–reactive unit in a ZIKV outbreak is 85% to 92% and remains constant over time.
Ultrastructural morphology of goblet cells of the conjunctiva of dogs
Authors: Araújo Rosélia L. S. , Corrêa José R. , Galera Paula D. 
Published: April 2019

AbstractObjectiveTo describe the morphology of goblet cells of the eyelid conjunctiva in dogs using transmission and scanning electron microscopy.Animal studiedTen dogs, both male and female of different breeds, with no ocular changes were examined (20 eyes).ProceduresTen samples of conjunctiva were collected and processed for scanning and transmission electron microscopy (SEM and TEM), while another 10 samples were stained with Schiff's periodic stain (SPA) and alcian blue, pH 2.5, and analyzed using light microscopy.ResultsScanning electron microscopy revealed several points of mucus extrusion in the free apical portion of the goblet cells as well as a wide distribution of lymphoid follicles and macrophages intermingling with the microvilli of palpebral epithelium cells. TEM revealed normal goblet cells that were predominantly oval with wide cytoplasm of different diameters, and large vesicles with heterogeneous granules and free edges, suggesting the release of mucus content onto the conjunctival surface. Cytoplasmic organelles, such as the Golgi apparatus, endoplasmic reticulum, and a high number of mitochondria were also observed. All the samples were positive for SPA and alcian blue staining.ConclusionThis is the first study to evaluate the goblet cells of the eyelid conjunctiva in healthy dogs using electron microscopy techniques. These results are useful for comparing the palpebral conjunctiva of dogs without ocular changes to palpebral conjunctiva of dogs and other species with ocular changes.
Design and Transmission Error Analysis of CBR Reducer
Authors: Sun Xiaoxiao , Han Liang , Wang Jian 
Published: April 2019

Abstract
A new one-stage type cycloid drive reducer named China Bearing Reducer (CBR) is designed and its tooth contact analysis is investigated. First, the CAD model is built in SolidWorks and the structure of CBR reducer is introduced. Its advantages and disadvantages are compared with rotor vector (RV) reducer and harmonic drive reducer. Second, the mathematic model of cycloid profile and modified cycloid profile are established based on gear meshing and differential geometry, and the tooth shapes of three different modifications are compared with CBR25 reducer. Third, the conventional TCA method is described and a new TCA method by using discretized points is proposed to calculate transmission error and contact force of cycloid drive. Both the methods are used to compute the unloaded transmission error of CBR25 reducer to compare the computational efficiency. Finally, three different modified methods of tooth profile are investigated by using the new TCA method to calculate transmission error and contact force of CBR25 reducer, and the results show that the negative isometric and negative offset modified method is best for CBR25 reducer to reduce transmission error and contact force. The prototype of CBR25 reducer is manufactured and the transmission error and hysteresis curve are measured by using a testing bench. The results show that the new TCA method can be used to calculate transmission error and help better design the CBR reducer.