bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Changes from Depolarizing to Hyperpolarizing GABAergic Actions during Giant Depolarizing Potentials in the Neonatal Rat Hippocampus
Authors: Khalilov Ilgam , Minlebaev Marat , Mukhtarov Marat , Khazipov Roustem 
Published: September 2015

During development, GABA exerts depolarizing action on immature neurons and, acting in synergy with glutamate, drives giant depolarizing potentials (GDPs) in the hippocampal network. Yet, blockade of the GABA(A) receptors transforms GDPs to epileptiform discharges suggesting dual, both excitatory and inhibitory, actions of GABA in the immature hippocampal network. However, the nature of this dualism in early GABA actions is poorly understood. Here we characterized the dynamics of synaptic currents mediated by GABA(A) and glutamate receptors through an estimation of the changes in their conductance and driving forces in neonatal rat CA3 pyramidal cells during GDPs. We found that depolarizing GABAergic and glutamatergic currents act in synergy at the GDPs' onset. However, during the peak of the population discharge, the inward synaptic current was essentially mediated by glutamate receptors whereas GABA currents transiently switched their direction from depolarizing to hyperpolarizing as a result of neuronal depolarization above the GABA(A) reversal potential. Thus, the action of GABA on CA3 pyramidal cells dynamically changes during GDPs from excitatory at the GDPs' onset to inhibitory at the GDPs' peak. We propose that the dynamic changes in GABA actions occurring during GDPs enable GABAergic interneurons not only to initiate the discharge of pyramidal cells but also to control excitation in the recurrent CA3 network preventing epileptiform synchronization.SIGNIFICANCE STATEMENTDuring development GABA exerts a depolarizing action on immature neurons. However, at the network level the effects of GABA are complex involving both excitatory and inhibitory actions. Here we show that GABA actions critically depend on the network state. Although GABA depolarizes neurons at rest and at the onset of population bursts, it transiently becomes hyperpolarizing at the peak of the population bursts. These dynamic changes in GABA actions enable GABAergic interneurons not only to initiate the network discharge but also to control excitation to prevent epileptiform synchronization.
Impaired Cholinergic Excitation of Prefrontal Attention Circuitry in the TgCRND8 Model of Alzheimer's Disease
Authors: Proulx Éliane , Fraser Paul , McLaurin JoAnne , Lambe Evelyn K. 
Published: September 2015

Attention deficits in Alzheimer's disease can exacerbate its other cognitive symptoms, yet relevant disruptions of key prefrontal circuitry are not well understood. Here, in the TgCRND8 mouse model of this neurological disorder, we demonstrate and characterize a disruption of cholinergic excitation in the major corticothalamic layer of the prefrontal cortex, in which modulation by acetylcholine is essential for optimal attentional function. Using electrophysiology with concurrent multiphoton imaging, we show that layer 6 pyramidal cells are unable to sustain cholinergic excitation to the same extent as their nontransgenic littermate controls, as a result of the excessive activation of calcium-activated hyperpolarizing conductances. We report that cholinergic excitation can be improved in TgCRND8 cortex by pharmacological blockade of SK channels, suggesting a novel target for the treatment of cognitive dysfunction in Alzheimer's disease.SIGNIFICANCE STATEMENTAlzheimer's disease is accompanied by attention deficits that exacerbate its other cognitive symptoms. In brain slices of a mouse model of this neurological disorder, we demonstrate, characterize, and rescue impaired cholinergic excitation of neurons essential for optimal attentional performance. In particular, we show that the excessive activation of a calcium-activated potassium conductance disrupts the acetylcholine excitation of prefrontal layer 6 pyramidal neurons and that its blockade normalizes responses. These findings point to a novel potential target for the treatment of cognitive dysfunction in Alzheimer's disease.
“A Better Civilization” through Tourism
Authors: Ochonicky Adam 
Published: September 2015

Adam Ochonicky, “‘A Better Civilization’ through Tourism: Cultural Appropriation in The Marble Faun” (pp. 221–237)
This essay argues that Nathaniel Hawthorne’s The Marble Faun: Or, The Romance of Monte Beni (1860) is an attempt to situate the United States within a lineage of “great” nations via the depiction of tourism abroad in the nineteenth century. In The Marble Faun, Hawthorne suggests that the historical legacies of nations are dependent on the production of art objects, literature, and cultural sites that demonstrate the sophistication of a given national identity. As such, the novel’s narrative revolves around the experiences of a pair of American artists, Hilda and Kenyon, during their stay in Rome. Hawthorne continually emphasizes the duo’s remarkable skills as evaluators and copyists of Italian art in order to legitimize their—and, by proxy, the United States’—appropriation of Italy’s culture and historical stature. Throughout the novel, Hawthorne disparages the degraded state of then-contemporary Rome, while elevating the comparatively youthful United States as the rightful inheritor of Italy’s illustrious past. Essentially, by situating critical work on the nineteenth-century “realm of leisure” alongside twenty-first-century theories of tourism, this essay provides a framework for understanding the complex interconnections between transnational tourism and the development of American cultural identity in The Marble Faun.
Alternative Hfq‐sRNA interaction modes dictate alternative mRNA recognition
Authors: Schu Daniel J , Zhang Aixia , Gottesman Susan , Storz Gisela 
Published: September 2015

AbstractMany bacteria use small RNAs (sRNAs) and the RNA chaperone Hfq to regulate mRNA stability and translation. Hfq, a ring‐shaped homohexamer, has multiple faces that can bind both sRNAs and their mRNA targets. We find that Hfq has at least two distinct ways in which it interacts with sRNAs; these different binding properties have strong effects on the stability of the sRNA in vivo and the sequence requirements of regulated mRNAs. Class I sRNAs depend on proximal and rim Hfq sites for stability and turn over rapidly. Class II sRNAs are more stable and depend on the proximal and distal Hfq sites for stabilization. Using deletions and chimeras, we find that while Class I sRNAs regulate mRNA targets with previously defined ARN repeats, Class II sRNAs regulate mRNAs carrying UA‐rich rim‐binding sites. We discuss how these different binding modes may correlate with different roles in the cell, with Class I sRNAs acting as emergency responders and Class II sRNAs acting as silencers.
Five-year prospective evaluation of thyroid function in girls with subclinical mild hypothyroidism of different etiology
Authors: Wasniewska Malgorzata , Aversa Tommaso , Salerno Mariacarolina , Corrias Andrea , Messina Maria Francesca , Mussa Alessandro , Capalbo Donatella , De Luca Filippo , Valenzise Mariella 
Published: September 2015

AimTo follow-up for 5 years thyroid status evolution in 127 girls with mild (TSH 5–10 mU/l) subclinical hypothyroidism (SH) of different etiologies.PatientsThe population was divided into two age-matched groups of 42 and 85 girls with either idiopathic (group A) or Hashimoto's thyroiditis (HT)-related SH (group B). Group B was in turn divided into three subgroups, according to whether SH was either isolated or associated with Turner syndrome (TS) or Down syndrome (DS).ResultsAt the end of follow-up the rate of girls who became euthyroid was higher in group A (61.9% vs 10.6%), whereas the rates of patients who remained SH (55.3% vs 26.2%), became overtly hypothyroid (30.6% vs 11.9%) or required levothyroxine (l-T4) therapy (63.5% vs 23.8%) were higher in group B. Among the girls of group B, the risk of remaining SH or developing overt hypothyroidism was higher in the subgroups with TS or DS than in those with isolated HT.ConclusionsLong-term prognosis of mild and idiopathic SH is frequently benign, even though a l-T4 treatment may be needed throughout follow-up in almost a quarter of cases; long-term prognosis is different in the girls with either idiopathic or HT-related SH; and the association with either TS or DS impairs the outcome of HT-related SH.
Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in BothDrosophila melanogasterandHomo sapiens
Authors: Cooper Brandon S , Burrus Chad R , Ji Chao , Hahn Matthew W , Montooth Kristi L 
Published: September 2015

AbstractDeleterious mutations contribute to polymorphism even when selection effectively prevents their fixation. The efficacy of selection in removing deleterious mitochondrial mutations from populations depends on the effective population size (Ne) of the mitochondrial DNA and the degree to which a lack of recombination magnifies the effects of linked selection. Using complete mitochondrial genomes from Drosophila melanogaster and nuclear data available from the same samples, we reexamine the hypothesis that nonrecombining animal mitochondrial DNA harbor an excess of deleterious polymorphisms relative to the nuclear genome. We find no evidence of recombination in the mitochondrial genome, and the much-reduced level of mitochondrial synonymous polymorphism relative to nuclear genes is consistent with a reduction in Ne. Nevertheless, we find that the neutrality index, a measure of the excess of nonsynonymous polymorphism relative to the neutral expectation, is only weakly significantly different between mitochondrial and nuclear loci. This difference is likely the result of the larger proportion of beneficial mutations in X-linked relative to autosomal loci, and we find little to no difference between mitochondrial and autosomal neutrality indices. Reanalysis of published data from Homo sapiens reveals a similar lack of a difference between the two genomes, although previous studies have suggested a strong difference in both species. Thus, despite a smaller Ne, mitochondrial loci of both flies and humans appear to experience similar efficacies of purifying selection as do loci in the recombining nuclear genome.
Genetic Linkage Mapping of Economically Important Traits in Cultivated Tetraploid Potato (Solanum tuberosum L.)
Authors: Massa Alicia N , Manrique-Carpintero Norma C , Coombs Joseph J , Zarka Daniel G , Boone Anne E , Kirk William W , Hackett Christine A , Bryan Glenn J , Douches David S 
Published: September 2015

Abstract
The objective of this study was to construct a single nucleotide polymorphism (SNP)-based genetic map at the cultivated tetraploid level to locate quantitative trait loci (QTL) contributing to economically important traits in potato (Solanum tuberosum L.). The 156 F1 progeny and parents of a cross (MSL603) between “Jacqueline Lee” and “MSG227-2” were genotyped using the Infinium 8303 Potato Array. Furthermore, the progeny and parents were evaluated for foliar late blight reaction to isolates of the US-8 genotype of Phytophthora infestans (Mont.) de Bary and vine maturity. Linkage analyses and QTL mapping were performed using a novel approach that incorporates allele dosage information. The resulting genetic maps contained 1972 SNP markers with an average density of 1.36 marker per cM. QTL mapping identified the major source of late blight resistance in “Jacqueline Lee.” The best SNP marker mapped ∼0.54 Mb from a resistance hotspot on the long arm of chromosome 9. For vine maturity, the major-effect QTL was located on chromosome 5 with allelic effects from both parents. A candidate SNP marker for this trait mapped ∼0.25 Mb from the StCDF1 gene, which is a candidate gene for the maturity trait. The identification of markers for P. infestans resistance will enable the introgression of multiple sources of resistance through marker-assisted selection. Moreover, the discovery of a QTL for late blight resistance not linked to the QTL for vine maturity provides the opportunity to use marker-assisted selection for resistance independent of the selection for vine maturity classifications.
Identification and Correction of Sample Mix-Ups in Expression Genetic Data: A Case Study
Authors: Broman Karl W , Keller Mark P , Broman Aimee Teo , Kendziorski Christina , Yandell Brian S , Sen Śaunak , Attie Alan D 
Published: September 2015

AbstractIn a mouse intercross with more than 500 animals and genome-wide gene expression data on six tissues, we identified a high proportion (18%) of sample mix-ups in the genotype data. Local expression quantitative trait loci (eQTL; genetic loci influencing gene expression) with extremely large effect were used to form a classifier to predict an individual’s eQTL genotype based on expression data alone. By considering multiple eQTL and their related transcripts, we identified numerous individuals whose predicted eQTL genotypes (based on their expression data) did not match their observed genotypes, and then went on to identify other individuals whose genotypes did match the predicted eQTL genotypes. The concordance of predictions across six tissues indicated that the problem was due to mix-ups in the genotypes (although we further identified a small number of sample mix-ups in each of the six panels of gene expression microarrays). Consideration of the plate positions of the DNA samples indicated a number of off-by-one and off-by-two errors, likely the result of pipetting errors. Such sample mix-ups can be a problem in any genetic study, but eQTL data allow us to identify, and even correct, such problems. Our methods have been implemented in an R package, R/lineup.
bz-rates: A Web Tool to Estimate Mutation Rates from Fluctuation Analysis
Authors: Gillet-Markowska Alexandre , Louvel Guillaume , Fischer Gilles 
Published: September 2015

Abstract
Fluctuation analysis is the standard experimental method for measuring mutation rates in micro-organisms. The appearance of mutants is classically described by a Luria-Delbrück distribution composed of two parameters: the number of mutations per culture (m) and the differential growth rate between mutant and wild-type cells (b). A precise estimation of these two parameters is a prerequisite to the calculation of the mutation rate. Here, we developed bz-rates, a Web tool to calculate mutation rates that provides three useful advances over existing Web tools. First, it allows taking into account b, the differential growth rate between mutant and wild-type cells, in the estimation of m with the generating function. Second, bz-rates allows the user to take into account a deviation from the Luria-Delbrück distribution called z, the plating efficiency, in the estimation of m. Finally, the Web site provides a graphical visualization of the goodness-of-fit between the experimental data and the model. bz-rates is accessible at http://www.lcqb.upmc.fr/bzrates.
Ultra-High Density, Transcript-Based Genetic Maps of Pepper Define Recombination in the Genome and Synteny Among Related Species
Authors: Hill Theresa , Ashrafi Hamid , Chin-Wo Sebastian Reyes , Stoffel Kevin , Truco Maria-Jose , Kozik Alexander , Michelmore Richard , Van Deynze Allen 
Published: September 2015

AbstractOur ability to assemble complex genomes and construct ultradense genetic maps now allows the determination of recombination rates, translocations, and the extent of genomic collinearity between populations, species, and genera. We developed two ultradense genetic linkage maps for pepper from single-position polymorphisms (SPPs) identified de novo with a 30,173 unigene pepper genotyping array. The Capsicum frutescens × C. annuum interspecific and the C. annuum intraspecific genetic maps were constructed comprising 16,167 and 3,878 unigene markers in 2108 and 783 genetic bins, respectively. Accuracies of marker groupings and orders are validated by the high degree of collinearity between the two maps. Marker density was sufficient to locate the chromosomal breakpoint resulting in the P1/P8 translocation between C. frutescens and C. annuum to a single bin. The two maps aligned to the pepper genome showed varying marker density along the chromosomes. There were extensive chromosomal regions with suppressed recombination and reduced intraspecific marker density. These regions corresponded to the pronounced nonrecombining pericentromeric regions in tomato, a related Solanaceous species. Similar to tomato, the extent of reduced recombination appears to be more pronounced in pepper than in other plant species. Alignment of maps with the tomato and potato genomes shows the presence of previously known translocations and a translocation event that was not observed in previous genetic maps of pepper.
SNP Assay Development for Linkage Map Construction, Anchoring Whole-Genome Sequence, and Other Genetic and Genomic Applications in Common Bean
Authors: Song Qijian , Jia Gaofeng , Hyten David L , Jenkins Jerry , Hwang Eun-Young , Schroeder Steven G , Osorno Juan M , Schmutz Jeremy , Jackson Scott A , McClean Phillip E , Cregan Perry B 
Published: September 2015

AbstractA total of 992,682 single-nucleotide polymorphisms (SNPs) was identified as ideal for Illumina Infinium II BeadChip design after sequencing a diverse set of 17 common bean (Phaseolus vulgaris L) varieties with the aid of next-generation sequencing technology. From these, two BeadChips each with &gt;5000 SNPs were designed. The BARCBean6K_1 BeadChip was selected for the purpose of optimizing polymorphism among market classes and, when possible, SNPs were targeted to sequence scaffolds in the Phaseolus vulgaris 14× genome assembly with sequence lengths &gt;10 kb. The BARCBean6K_2 BeadChip was designed with the objective of anchoring additional scaffolds and to facilitate orientation of large scaffolds. Analysis of 267 F2 plants from a cross of varieties Stampede × Red Hawk with the two BeadChips resulted in linkage maps with a total of 7040 markers including 7015 SNPs. With the linkage map, a total of 432.3 Mb of sequence from 2766 scaffolds was anchored to create the Phaseolus vulgaris v1.0 assembly, which accounted for approximately 89% of the 487 Mb of available sequence scaffolds of the Phaseolus vulgaris v0.9 assembly. A core set of 6000 SNPs (BARCBean6K_3 BeadChip) with high genotyping quality and polymorphism was selected based on the genotyping of 365 dry bean and 134 snap bean accessions with the BARCBean6K_1 and BARCBean6K_2 BeadChips. The BARCBean6K_3 BeadChip is a useful tool for genetics and genomics research and it is widely used by breeders and geneticists in the United States and abroad.
Evolutionary Fate of the Androgen Receptor−Signaling Pathway in Ray-Finned Fishes with a Special Focus on Cichlids
Authors: Lorin Thibault , Salzburger Walter , Böhne Astrid 
Published: September 2015

Abstract
The emergence of the steroid system is coupled to the evolution of multicellular animals. In vertebrates in particular, the steroid receptor repertoire has been shaped by genome duplications characteristic to this lineage. Here, we investigate for the first time the composition of the androgen receptor–signaling pathway in ray-finned fish genomes by focusing in particular on duplicates that emerged from the teleost-specific whole-genome duplication. We trace lineage- and species-specific duplications and gene losses for the genomic and nongenomic pathway of androgen signaling and subsequently investigate the sequence evolution of these genes. In one particular fish lineage, the cichlids, we find evidence for differing selection pressures acting on teleost-specific whole-genome duplication paralogs at a derived evolutionary stage. We then look into the expression of these duplicated genes in four cichlid species from Lake Tanganyika indicating, once more, rapid changes in expression patterns in closely related fish species. We focus on a particular case, the cichlid specific duplication of the rac1 GTPase, which shows possible signs of a neofunctionalization event.
Flux Control in a Defense Pathway inArabidopsis thalianaIs Robust to Environmental Perturbations and Controls Variation in Adaptive Traits
Authors: Olson-Manning Carrie F , Strock Christopher F , Mitchell-Olds Thomas 
Published: September 2015

AbstractThe connections leading from genotype to fitness are not well understood, yet they are crucial for a diverse set of disciplines. Uncovering the general properties of biochemical pathways that influence ecologically important traits is an effective way to understand these connections. Enzyme flux control (or, control over pathway output) is one such pathway property. The flux-controlling enzyme in the antiherbivory aliphatic glucosinolate pathway of Arabidopsis thaliana has majority flux control under benign greenhouse conditions and has evidence of nonneutral evolution. However, it is unknown how patterns of flux control may change in different environments, or if insect herbivores respond to differences in pathway flux. We test this, first through genetic manipulation of the loci that code for the aliphatic glucosinolate pathway enzymes under a variety of environments (reduced water, reduced soil nutrients, leaf wounding and methyl jasmonate treatments), and find that flux control is consistently in the first enzyme of the pathway. We also find that a generalist herbivore, Trichoplusia ni, modifies its feeding behavior depending on the flux through the glucosinolate pathway. The influence over herbivore behavior combined with the consistency of flux control suggests that genes controlling flux might be repeatedly targeted by natural selection in diverse environments and species.
Crisis y transformación de la educación superior: el lugar de las humanidades en Latinoamérica
Authors: García Herrera Alejandra 
Published: September 2015

<p>Este artículo analiza las transformaciones recientes de la universidad en Latinoamérica, como resultado de las propuestas de organismos internacionales, a finales del siglo pasado, que conciben la educación como base para el desarrollo económico. A través del estudio de la creciente bibliografía sobre la crisis de la educación superior en el continente, este trabajo busca esclarecer el vínculo entre universidad y sociedad que el enfoque corporativo ha propiciado y que ha puesto en riesgo la función social o intelectual de la universidad latinoamericana. </p>
Enhancement of Salt Rejection and Water Flux by Crosslinking-Induced Microstructure Change of N-substituted Polybenzimidazole Membranes
Authors: Aiba Motohiro , Tokuyama Takahiro , Matsumoto Hidetoshi , Tomioka Hiroki , Higashihara Tomoya , Ueda Mitsuru 
Published: September 2015

ABSTRACTCrosslinked or non-crosslinked ultrathin semipermeable membranes based on the N-butylated and N-butylsulfonated polybenzimidazole (BPBI and BSPBI) were successfully prepared by spin-coating method. Structural characterization by FTIR and WAXD revealed that the N-substitution and the crosslinked structure of PBI suppressed the hydrogen bonding and increased the d-spacing. Furthermore, positron annihilation lifetime spectroscopy (PALS) clearly showed the pore radius change from 0.27-0.29 nm to 0.33 nm by crosslinking. As a result, the enhancement of water flux and NaCl rejection was achieved by the crosslinking of the BPBI and BSPBI. Especially, the crosslinked N-butylsulfonated PBI (CL-BSPBI) membrane significantly improved not only salt rejection but also water flux (NaCl rejection : 46 %, water flux : 22.1 L m-2 h-1) compared to those of non-crosslinked BSPBI one (NaCl rejection : 11 %, water flux : 1.88 L m-2 h-1) due to both the Donnan effect and the formation of larger pores in the membrane, respectively.