bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sex chromosome turnovers and genetic drift: a simulation study
Authors: Saunders Paul A. , Neuenschwander Samuel , Perrin Nicolas 
Published: June 2018

AbstractThe recent advances of new genomic technologies have enabled the identification and characterization of sex chromosomes in an increasing number of nonmodel species, revealing that many plants and animals undergo frequent sex chromosome turnovers. What evolutionary forces drive these turnovers remains poorly understood, but it was recently proposed that drift might play a more important role than generally assumed. We analysed the dynamics of different types of turnovers using individual‐based simulations and show that when mediated by genetic drift, turnovers are usually easier to achieve than substitutions at neutral markers, but that their dynamics and relative likelihoods vary with the type of the resident and emergent sex chromosome system (XY and/or ZW) and the dominance relationships among the sex‐determining factors. Focusing on turnovers driven by epistatically dominant mutations, we find that drift‐mediated turnovers that preserve the heterogamety pattern are 2–4× more likely than those along which the heterogametic sex changes. This ratio nevertheless decreases along with effective population size and can even reverse in case of extreme polygyny. This can be attributed to a ‘drift‐induced’ selective force, known to influence transitions between male and female heterogamety, but which according to our study does not affect turnovers that preserve the heterogametic sex.
High‐P metamorphism of rodingites during serpentinite dehydration (Cerro del Almirez, Southern Spain): Implications for the redox state in subduction zones
Authors: Laborda‐López Casto , López‐Sánchez‐Vizcaíno Vicente , Marchesi Claudio , Gómez‐Pugnaire María T. , Garrido Carlos J. , Jabaloy‐Sánchez Antonio , Padrón‐Navarta José A. , Hidas Károly 
Published: June 2018

AbstractThe transition between antigorite‐serpentinite and chlorite‐harzburgite at Cerro del Almirez (Betic Cordillera, Southern Spain) exceptionally marks in the field the front of antigorite breakdown at high pressure (~16–19 kbar) and temperature (~650°C) in a paleosubducted serpentinite. These ultramafic lithologies enclose three types of metarodingite boudins of variable size surrounded by metasomatic reaction rims. Type 1 Grandite‐metarodingite (garnet+chlorite+diopside+titanite±magnetite±ilmenite) mainly crops out in the antigorite‐serpentinite domain and has three generations of garnet. Grossular‐rich Grt‐1 formed during rodingitization at the seafloor (<2 kbar, ~150–325°C, ~FMQ buffer). During subduction, the alternating growth of Grt‐2b (richer in andradite and pyralspite components than Grt‐1) and Grt‐3 (very rich in andradite component) reflects the change from internally buffered metamorphic conditions (>10 kbar, ~350–650°C, ~FMQ buffer) to influx events of oxidizing fluids (fO2 ~HM buffer) released by brucite breakdown in the host antigorite‐serpentinite. Type 2 Epidote‐metarodingite (epidote+diopside+titanite±garnet) derives from Type 1 and is the most abundant metarodingite type enclosed in dehydrated chlorite‐harzburgite. Type 2 formed by increasing μSiO2 (from −884 to −860 kJ/mol) and decreasing μCaO (from −708 to −725 kJ/mol) triggered by the flux of high amounts of oxidizing fluids during the high‐P antigorite breakdown in serpentinite. The growth of Grt‐4, with low‐grandite and high‐pyralspite components, in Type 2 metarodingite accounts for progressive reequilibration of garnet with changing intensive variables. Type 3 Pyralspite‐metarodingite (garnet+epidote+amphibole+chlorite±diopside+rutile) crops out in the chlorite‐harzburgite domain and formed at peak metamorphic conditions (16–19 kbar, 660–684°C) from Type 2 metarodingite. This transformation caused the growth of a last generation of pyralspite‐rich garnet (Grt‐5) and the recrystallization of diopside into tremolitic amphibole at decreasing fO2 and μCaO (from −726 to −735 kJ/mol) and increasing μMgO (from −630 to −626 kJ/mol) due to chemical mixing between the metarodingite and the reaction rims. The different bulk Fe3+/FeTotal ratios of antigorite‐serpentinite and chlorite‐harzburgite, and of the three metarodingite types, reflect the highly heterogeneous oxidation state of the subducting slab and likely point to the transfer of localized oxidized reservoirs, such as metarodingites, into the deep mantle.
Comparison of the pregnancy outcomes and the incidence of fetal congenital abnormalities in infertile women treated with letrozole and clomiphene citrate
Authors: Akbari Sene Azadeh , Ghorbani Selma , Ashrafi Mahnaz 
Published: June 2018

AbstractObjectivesThe aim of the study was to evaluate the incidence of congenital fetal anomalies reported among infertile Iranian women treated with letrozole compared to those treated with Clomiphene Citrate (CC).MethodsThis retrospective case–control study was performed based on information available from infertile patients referred to the Akbar‐Abadi Hospital IVF Center, Tehran, Iran, undergoing ovulation induction (OI) or intrauterine insemination (IUI) cycles from 2007 to 2014.We compared sonographic findings, fertility results, pregnancy complications and congenital anomalies in two groups of women treated with letrozole and CC.ResultsOverall, the results of the 2009 cycles including 1237 CC cycles and 772 letrozole cycles were evaluated. In spite of a higher chance of ovulation following CC treatment, overall fertility rates were similar in the two treatment groups. The frequency of adverse outcomes of pregnancy was similar in the two groups, except for the incidence of first trimester abortion, which was significantly higher in the CC‐treated group. The frequency of fetal anomalies and major chromosomal abnormalities in the Letrozole group was 4.76% (five cases), and in the CC group, it was 2.12% (three cases). This difference was not statistically significant.ConclusionBased on the findings of this study, it seems that the incidence of congenital anomalies in offspring after OI with letrozole is not increased compared to the CC group.
Cardiovascular disease in diabetes type 2: current concepts
Authors: Rosengren A. 
Published: June 2018

AbstractType 2 diabetes is a major and accelerating public health challenge. Between 1980 and 2014, a period of just 35 years, the number of adults with diabetes globally is estimated to have increased from 108 to 422 million, due not only to sharply rising obesity rates, but also to increasing population size, longer life expectancy, and rising prevalence of diabetes worldwide. Overall, worldwide age‐standardized adult diabetes prevalence doubled from 4.3% to 9.0% in men and from 5.0% to 7.9% in women. The largest increases in diabetes type 2 have been demonstrated in low‐ and middle‐income countries, whilst rises in high‐income countries have been less marked, or even flat. Diabetes type 2 rates in low‐ and middle‐income countries now in many instances surpass those in high‐income countries, in response to changes in lifestyle. One factor of particular concern are the large relative increases in type 2 diabetes amongst young individuals observed in many countries, their higher overall risk factor burden, long exposure to hyperglycaemia and greater risk of complications over the life course. Type 2 diabetes is increasingly found to be a heterogeneous condition, where risk of cardiovascular disease that traditionally has been estimated at 2–4 times that of the nondiabetic population varies substantially with diabetes phenotype and accordingly diabetes does not confer the same increase in relative or absolute risk in all people. New research shows that excess risk varies substantially with type of outcome, age, glycaemic control, the presence of renal complications and other factors. Heart failure, previously less recognized that other cardiovascular conditions, is increasingly coming into focus, because of strong links with poor glycaemic control and obesity. The knowledge about risk of cardiovascular disease in diabetes is almost entirely derived from high‐income countries, whereas there is comparatively very little data from low‐ and middle income countries, where the majority of persons with type 2 diabetes live, and where management in many cases is far from optimal. The reductions in cardiovascular disease incidence and mortality now observed in high‐income countries are encouraging, because this reinforces the fact that improvement is possible and that a near‐normal, or even normal life‐expectancy can be achieved in subtypes of type 2 diabetes.
Nitidine chloride represses Mcl‐1 protein via lysosomal degradation in oral squamous cell carcinoma
Authors: Yang In‐Hyoung , Jung Won , Kim Lee‐Han , Shin Ji‐Ae , Cho Nam‐Pyo , Hong Seong Doo , Hong Kyoung‐Ok , Cho Sung‐Dae 
Published: June 2018

BackgroundWe have shown previously that nitidine chloride (NC) induces apoptosis via inhibition of signal transducer and activator of transcription 3 (STAT3). However, its downstream molecules are not fully understood yet. Here, we report that NC as STAT3 inhibitor downregulates myeloid cell leukemia‐1 (Mcl‐1) protein in HSC‐3 and HSC‐4 human oral squamous cell carcinoma (OSCC) cells and a nude mouse tumor xenograft model.MethodsThis study investigated the effects of NC on Mcl‐1 expression in HSC‐3 and HSC‐4 cells using Western blotting, RT‐PCR, and dual‐luciferase assay. Immunohistochemistry was employed to evaluate Mcl‐1 expression levels in mouse tumor tissues. Construction of Mcl‐1 overexpression vector and transient transfection was done to test the apoptosis of HSC‐3 cells.ResultsNitidine chloride did not affect either mRNA level or promoter activity of Mcl‐1, and the decrease in Mcl‐1 protein by NC was caused by lysosome‐dependent degradation, but not proteasome‐dependent degradation. The overexpression of Mcl‐1 protein in OSCC cell lines was sufficient to block the induction of apoptosis. In addition, NC strongly reduced the expression level of Mcl‐1 protein compared with other STAT3 inhibitors such as cryptotanshione and S3I‐201 in OSCCs.ConclusionsOur findings suggest that NC triggers apoptosis via lysosome‐dependent Mcl‐1 protein degradation and could be chosen as a promising chemotherapeutic candidate against human OSCCs.
Geographic Distribution of Providers With a DEA Waiver to Prescribe Buprenorphine for the Treatment of Opioid Use Disorder: A 5‐Year Update
Authors: Andrilla C. Holly A. , Moore Tessa E. , Patterson Davis G. , Larson Eric H. 
Published: June 2018

AbstractPurposeOpioid use disorder (OUD) is a substantial public health problem. Buprenorphine is an effective medication‐assisted treatment (MAT) for OUD, but access is difficult for patients, especially in rural locations. To improve access, the Comprehensive Addiction and Recovery Act of 2016 extended the ability to get a Drug Enforcement Administration (DEA) waiver to prescribe buprenorphine to treat OUD to nurse practitioners (NPs) and physician assistants (PAs). This study summarizes the geographic distribution of waivered physicians, NPs, and PAs at the end of 2017 and compares it to the distribution of waivered physicians 5 years earlier.MethodsUsing the DEA list of providers with a waiver to prescribe buprenorphine to treat OUD and the Area Health Resources File, we assigned waivered providers to counties in 1 of 4 geographic categories. We calculated the number of counties in each category that did not have a waivered provider and county provider to population ratios and then compared our results to the waivered workforce in 2012.FindingsThe availability of a physician with a DEA waiver to provide office‐based MAT has increased across all geographic categories since 2012. More than half of all rural counties (56.3%) still lack a provider, down from 67.1% in 2012. Almost one‐third (29.8%) of rural Americans compared to 2.2% of urban Americans live in a county without a buprenorphine provider. NPs and PAs add otherwise lacking treatment availability in 56 counties (43 rural).ConclusionsOverall, MAT access has improved, but rural communities still experience treatment disparities.
Kleine‐Levin syndrome is associated with LMOD3 variants
Authors: Al Shareef Saad M. , Basit Sulman , Li Sha , Pfister Corinne , Pradervand Sylvain , Lecendreux Michel , Mayer Geert , Dauvilliers Yves , Salpietro Vincenzo , Houlden Henry , BaHammam Ahmed S. , Tafti Mehdi 
Published: June 2018

AbstractKleine‐Levin syndrome (KLS) is a rare periodic hypersomnia with associated behavioural abnormalities but with often favourable prognosis. There is excess risk of KLS in first‐degree relatives, suggesting a strong genetic contribution. So far, no mutation is identified in KLS and comprehensive genetic analysis of affected individuals is lacking. Here we performed whole genome single‐nucleotide polymorphism (SNP) genotyping and exome sequencing in a large family with seven affected members. The identified gene with a mutation was resequenced in 38 sporadic KLS patients and the expression of the gene product was mapped in the mouse brain. Linkage analysis mapped the disease locus to chromosome 3 and exome analysis identified a heterozygous missense variant in LMOD3 (p.E142D) in the linkage interval. The variant was found to segregate in all affected and one presumably unaffected member of the family. Resequencing LMOD3 in 38 other KLS patients and their families revealed three other low frequency or rare missense variants in seven cases that were inherited with incomplete penetrance. LMOD3 is expressed in the brain and colocalized with major structures involved in the regulation of vigilance states. LMOD proteins are structural proteins and seem to be developmentally regulated. Our findings suggest that KLS might be a structural/neurodevelopmental brain disease.
Vygotsky, Wittgenstein, and sociocultural theory
Authors: Newman Stephen 
Published: June 2018

AbstractThis paper considers the use made of Vygotsky's work by many who take a sociocultural perspective and, in particular, by those who use his work to advance a particular view of second language acquisition and the ‘silent period’. It is argued that Vygotsky's account as represented in Thought and Language (Vygotsky, ) needs to be thought of as consisting of two distinct aspects: first, the observations he made (or claimed to have made) and, second, the theoretical account he proposed to explain them. It is shown that some of Vygotsky's observations are problematic but that, even if they are accepted, Vygotsky's theoretical account suffers from fundamental difficulties. Thus the support claimed from Vygotsky in accounts of second language acquisition is misplaced, first because of those difficulties and, second, because many who claim support from Vygotsky, do not need or even use his theory but instead focus their attention on his empirical observations and assume incorrectly that if their own empirical observations match Vygotsky's, then Vygotsky's theory can be accepted. Wittgenstein's later philosophy is shown to provide a perspective which dispels confusions about, and gives us a clearer insight into, the issues.
The relative contributions of seed and pollen dispersal to gene flow and genetic diversity in seedlings of a tropical palm
Authors: Browne Luke , Ottewell Kym , Sork Victoria L. , Karubian Jordan 
Published: June 2018

AbstractSeed and pollen dispersal shape patterns of gene flow and genetic diversity in plants. Pollen is generally thought to travel longer distances than seeds, but seeds determine the ultimate location of gametes. Resolving how interactions between these two dispersal processes shape microevolutionary processes is a long‐standing research priority. We unambiguously isolated the separate and combined contributions of these two dispersal processes in seedlings of the animal‐dispersed palm Oenocarpus bataua to address two questions. First, what is the spatial extent of pollen versus seed movement in a system characterized by long‐distance seed dispersal? Second, how does seed dispersal mediate seedling genetic diversity? Despite evidence of frequent long‐distance seed dispersal, we found that pollen moves much further than seeds. Nonetheless, seed dispersal ultimately mediates genetic diversity and fine‐scale spatial genetic structure. Compared to undispersed seedlings, seedlings dispersed by vertebrates were characterized by higher female gametic and diploid seedling diversity and weaker fine‐scale spatial genetic structure for female gametes, male gametes and diploid seedlings. Interestingly, the diversity of maternal seed sources at seed deposition sites (Nem) was associated with higher effective number of pollen sources (Nep), higher effective number of parents (Ne) and weaker spatial genetic structure, whereas seed dispersal distance had little impact on these or other parameters we measured. These findings highlight the importance maternal seed source diversity (Nem) at frugivore seed deposition sites in driving emergent patterns of fine‐scale genetic diversity and structure.
Kin discrimination and outer membrane exchange in Myxococcus xanthus: A comparative analysis among natural isolates
Authors: Wielgoss Sébastien , Fiegna Francesca , Rendueles Olaya , Yu Yuen‐Tsu N. , Velicer Gregory J. 
Published: June 2018

AbstractGenetically similar cells of the soil bacterium Myxococcus xanthus cooperate at multiple social behaviours, including motility and multicellular development. Another social interaction in this species is outer membrane exchange (OME), a behaviour of unknown primary benefit in which cells displaying closely related variants of the outer membrane protein TraA transiently fuse and exchange membrane contents. Functionally incompatible TraA variants do not mediate OME, which led to the proposal that TraA incompatibilities determine patterns of intercellular cooperation in nature, but how this might occur remains unclear. Using natural isolates from a centimetre‐scale patch of soil, we analyse patterns of TraA diversity and ask whether relatedness at TraA is causally related to patterns of kin discrimination in the form of both colony‐merger incompatibilities (CMIs) and interstrain antagonisms. A large proportion of TraA functional diversity documented among global isolates is predicted to be contained within this cm‐scale population. We find evidence of balancing selection on the highly variable PA14‐portion of TraA and extensive transfer of traA alleles across genomic backgrounds. CMIs are shown to be common among strains identical at TraA, suggesting that CMIs are not generally caused by TraA dissimilarity. Finally, it has been proposed that interstrain antagonisms might be caused by OME‐mediated toxin transfer. However, we predict that most strain pairs previously shown to exhibit strong antagonisms are incapable of OME due to TraA dissimilarity. Overall, our results suggest that most documented patterns of kin discrimination in a natural population of M. xanthus are not causally related to the TraA sequences of interactants.
Functional plasticity of antibacterial EndoU toxins
Authors: Michalska Karolina , Quan Nhan Dinh , Willett Julia L. E. , Stols Lucy M. , Eschenfeldt William H. , Jones Allison M. , Nguyen Josephine Y. , Koskiniemi Sanna , Low David A. , Goulding Celia W. , Joachimiak Andrzej , Hayes Christopher S. 
Published: June 2018

AbstractBacteria use several different secretion systems to deliver toxic EndoU ribonucleases into neighboring cells. Here, we present the first structure of a prokaryotic EndoU toxin in complex with its cognate immunity protein. The contact‐dependent growth inhibition toxin CdiA‐CTSTECO31 from Escherichia coli STEC_O31 adopts the eukaryotic EndoU fold and shares greatest structural homology with the nuclease domain of coronavirus Nsp15. The toxin contains a canonical His‐His‐Lys catalytic triad in the same arrangement as eukaryotic EndoU domains, but lacks the uridylate‐specific ribonuclease activity that characterizes the superfamily. Comparative sequence analysis indicates that bacterial EndoU domains segregate into at least three major clades based on structural variations in the N‐terminal subdomain. Representative EndoU nucleases from clades I and II degrade tRNA molecules with little specificity. In contrast, CdiA‐CTSTECO31 and other clade III toxins are specific anticodon nucleases that cleave tRNAGlu between nucleotides C37 and m2A38. These findings suggest that the EndoU fold is a versatile scaffold for the evolution of novel substrate specificities. Such functional plasticity may account for the widespread use of EndoU effectors by diverse inter‐bacterial toxin delivery systems.
Assessment of the interaction between the flux‐signaling metabolite fructose‐1,6‐bisphosphate and the bacterial transcription factors CggR and Cra
Authors: Bley Folly Brenda , Ortega Alvaro D. , Hubmann Georg , Bonsing‐Vedelaar Silke , Wijma Hein J. , van der Meulen Pieter , Milias‐Argeitis Andreas , Heinemann Matthias 
Published: June 2018

SummaryBacteria regulate cell physiology in response to extra‐ and intracellular cues. Recent work showed that metabolic fluxes are reported by specific metabolites, whose concentrations correlate with flux through the respective metabolic pathway. An example of a flux‐signaling metabolite is fructose‐1,6‐bisphosphate (FBP). In turn, FBP was proposed to allosterically regulate master regulators of carbon metabolism, Cra in Escherichia coli and CggR in Bacillus subtilis. However, a number of questions on the FBP‐mediated regulation of these transcription factors is still open. Here, using thermal shift assays and microscale thermophoresis we demonstrate that FBP does not bind Cra, even at millimolar physiological concentration, and with electrophoretic mobility shift assays we also did not find FBP‐mediated impairment of Cra’s affinity for its operator site, while fructose‐1‐phosphate does. Furthermore, we show for the first time that FBP binds CggR within the millimolar physiological concentration range of the metabolite, and decreases DNA‐binding activity of this transcription factor. Molecular docking experiments only identified a single FBP binding site CggR. Our results provide the long thought after clarity with regards to regulation of Cra activity in E. coli and reveals that E. coli and B. subtilis use distinct cellular mechanism to transduce glycolytic flux signals into transcriptional regulation.
Variation in hydroclimate sustains tropical forest biomass and promotes functional diversity
Authors: Powell Thomas L. , Koven Charles D. , Johnson Daniel J. , Faybishenko Boris , Fisher Rosie A. , Knox Ryan G. , McDowell Nate G. , Condit Richard , Hubbell Stephen P. , Wright S. Joseph , Chambers Jeffrey Q. , Kueppers Lara M. 
Published: June 2018

Summary

The fate of tropical forests under climate change is unclear as a result, in part, of the uncertainty in projected changes in precipitation and in the ability of vegetation models to capture the effects of drought‐induced mortality on aboveground biomass (AGB).

We evaluated the ability of a terrestrial biosphere model with demography and hydrodynamics (Ecosystem Demography, ED2‐hydro) to simulate AGB and mortality of four tropical tree plant functional types (PFTs) that operate along light‐ and water‐use axes. Model predictions were compared with observations of canopy trees at Barro Colorado Island (BCI), Panama. We then assessed the implications of eight hypothetical precipitation scenarios, including increased annual precipitation, reduced inter‐annual variation, El Niño‐related droughts and drier wet or dry seasons, on AGB and functional diversity of the model forest.

When forced with observed meteorology, ED2‐hydro predictions capture multiple BCI benchmarks. ED2‐hydro predicts that AGB will be sustained under lower rainfall via shifts in the functional composition of the forest, except under the drier dry‐season scenario.

These results support the hypothesis that inter‐annual variation in mean and seasonal precipitation promotes the coexistence of functionally diverse PFTs because of the relative differences in mortality rates. If the hydroclimate becomes chronically drier or wetter, functional evenness related to drought tolerance may decline.