bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reward, Salience, and Agency in Event-Related Potentials for Appetitive and Aversive Contexts
Authors: Stewardson Harry J , Sambrook Thomas D 
Published: April 2021

Abstract
Cognitive architectures tasked with swiftly and adaptively processing biologically important events are likely to classify these on two central axes: motivational salience, that is, those events’ importance and unexpectedness, and motivational value, the utility they hold, relative to that expected. Because of its temporal precision, electroencephalography provides an opportunity to resolve processes associated with these two axes. A focus of attention for the last two decades has been the feedback-related negativity (FRN), a frontocentral component occurring 240–340 ms after valenced events that are not fully predicted. Both motivational salience and value are present in such events and competing claims have been made for which of these is encoded by the FRN. The present study suggests that motivational value, in the form of a reward prediction error, is the primary determinant of the FRN in active contexts, while in both passive and active contexts, a weaker and earlier overlapping motivational salience component may be present.
Forecasting Trachoma Control and Identifying Transmission-Hotspots
Authors: Blumberg Seth , Prada Joaquin M , Tedijanto Christine , Deiner Michael S , Godwin William W , Emerson Paul M , Hooper Pamela J , Borlase Anna , Hollingsworth T Deirdre , Oldenburg Catherine E , Porco Travis C , Arnold Benjamin F , Lietman Thomas M 
Published: April 2021

AbstractBackgroundTremendous progress towards elimination of trachoma as a public health problem has been made. However, there are areas where the clinical indicator of disease, trachomatous inflammation—follicular (TF), remains prevalent. We quantify the progress that has been made, and forecast how TF prevalence will evolve with current interventions. We also determine the probability that a district is a transmission-hotspot based on its TF prevalence (ie, reproduction number greater than one).MethodsData on trachoma prevalence come from the GET2020 global repository organized by the World Health Organization and the International Trachoma Initiative. Forecasts of TF prevalence and the percent of districts with local control is achieved by regressing the coefficients of a fitted exponential distribution for the year-by-year distribution of TF prevalence. The probability of a district being a transmission-hotspot is extrapolated from the residuals of the regression.ResultsForecasts suggest that with current interventions, 96.5% of surveyed districts will have TF prevalence among children aged 1–9 years &lt;5% by 2030 (95% CI: 86.6%–100.0%). Districts with TF prevalence &lt; 20% appear unlikely to be transmission-hotspots. However, a district having TF prevalence of over 28% in 2016–2019 corresponds to at least 50% probability of being a transmission-hotspot.ConclusionsSustainable control of trachoma appears achievable. However there are transmission-hotspots that are not responding to annual mass drug administration of azithromycin and require enhanced treatment in order to reach local control.
Gaze Estimation Using Neural Network And Logistic Regression
Authors: Xia Yifan , Liang Baosheng , Li Zhaotong , Gao Song 
Published: April 2021

Abstract
Currently, a large number of mature methods are available for gaze estimation. However, most regular gaze estimation approaches require additional hardware or platforms with professional equipment for data collection or computing that typically involve high costs and are relatively tedious. Besides, the implementation is particularly complex. Traditional gaze estimation approaches usually require systematic prior knowledge or expertise for practical operations. Moreover, they are primarily based on the characteristics of pupil and iris, which uses pupil shapes or infrared light and iris glint to estimate gaze, requiring high-quality images shot in special environments and other light source or professional equipment. We herein propose a two-stage gaze estimation method that relies on deep learning methods and logistic regression, which can be applied to various mobile platforms without additional hardware devices or systematic prior knowledge. A set of automatic and fast data collection mechanism is designed for collecting gaze images through a mobile platform camera. Additionally, we propose a new annotation method that improves the prediction accuracy and outperforms the traditional gridding annotation method. Our method achieves good results and can be adapted to different applications.
Neuronal nitric oxide synthase regulates regional brain perfusion in healthy humans
Authors: O’Gallagher Kevin , Puledda Francesca , O’Daly Owen , Ryan Matthew , Dancy Luke , Chowienczyk Philip J , Zelaya Fernando , Goadsby Peter J , Shah Ajay M 
Published: April 2021

Abstract

Aims
Neuronal nitric oxide synthase (nNOS) is highly expressed within the cardiovascular and nervous systems. Studies in genetically modified mice suggest roles in brain blood flow regulation while dysfunctional nNOS signalling is implicated in cerebrovascular ischaemia and migraine. Previous human studies have investigated the effects of non-selective NOS inhibition but there has been no direct investigation of the role of nNOS in human cerebrovascular regulation. We hypothesized that inhibition of the tonic effects of nNOS would result in global or localized changes in cerebral blood flow (CBF), as well as changes in functional brain connectivity.

Methods and results
We investigated the acute effects of a selective nNOS inhibitor, S-methyl-L-thiocitrulline (SMTC), on CBF and brain functional connectivity in healthy human volunteers (n = 19). We performed a randomized, placebo-controlled, crossover study with either intravenous SMTC or placebo, using magnetic resonance imaging protocols with arterial spin labelling and functional resting state neuroimaging. SMTC infusion induced an ∼4% decrease in resting global CBF [−2.3 (−0.3, −4.2) mL/100g/min, mean (95% confidence interval, CI), P = 0.02]. In a whole-brain voxel-wise factorial-design comparison of CBF maps, we identified a localized decrease in regional blood flow in the right hippocampus and parahippocampal gyrus following SMTC vs. placebo (2921 voxels; T = 7.0; x = 36; y = −32; z = −12; P &lt; 0.001). This was accompanied by a decrease in functional connectivity to the left superior parietal lobule vs. placebo (484 voxels; T = 5.02; x = −14; y = −56; z = 74; P = 0.009). These analyses adjusted for the modest changes in mean arterial blood pressure induced by SMTC as compared to placebo [+8.7 mmHg (+1.8, +15.6), mean (95% CI), P = 0.009].

Conclusions
These data suggest a fundamental physiological role of nNOS in regulating regional CBF and functional connectivity in the human hippocampus. Our findings have relevance to the role of nNOS in the regulation of cerebral perfusion in health and disease.
Comprehensive cardiac rehabilitation for patients following infective endocarditis: results of the randomized CopenHeartIE trial
Authors: Rasmussen Trine Bernholdt , Zwisler Ann-Dorthe , Risom Signe Stelling , Sibilitz Kirstine Lærum , Christensen Jan , Bundgaard Henning , Moons Philip , Thygesen Lau Caspar , Lindschou Jane , Norekvål Tone Merete , Berg Selina Kikkenborg 
Published: April 2021

Abstract

Aims
Infective endocarditis is a complex and highly mortal disease requiring lengthy treatment. Physical and mental deconditioning is common. Nonetheless, rehabilitation is virtually unexplored in this population. The aim of this trial was therefore to investigate the effects of cardiac rehabilitation in patients following endocarditis.

Methods and results
In a randomized trial, adults with left-sided or cardiac device endocarditis were randomized 1:1 to 12 weeks of physical exercise training and five psycho-educational consultations (cardiac rehabilitation) vs. usual care without rehabilitation (control). Primary outcome was mental health measured by SF-36 Mental Component Summary (MCS) at 6 months. Secondary outcome was physical capacity measured by peak oxygen uptake (VO2) at 4 months. Exploratory outcomes were investigated. Low inclusion rate resulted in trial termination before reaching the target sample size. A total of 117 participants (mean age: 60 years, 81% male) were randomized to cardiac rehabilitation (n = 58) or to control (n = 59). Mental health and physical capacity at baseline were generally poor (MCS: 38.9–42.2 points, VO2 peak: 16.1–16.6 mL/kg/min). Cardiac rehabilitation compared with control showed no effect on mental health (MCS: 44.6 points vs. 48.8 points, P = 0.41) or physical capacity (VO2 peak: 19.9 mL/kg/min vs. 18.0 mL/kg/min, P = 0.09). Effects favouring the intervention were identified in exploratory outcomes including general fatigue (P = 0.005), and physical capacity as maximal power (W) (P = 0.005). Adherence to the intervention was 28%.

Conclusions
Results indicate no effect of cardiac rehabilitation in patients following endocarditis; however, lack of statistical power and poor adherence render findings inconclusive. Valuable insight into patients’ capabilities and safety was gained, and further investigations into rehabilitation needs and modes of delivery in this high-need population should be a future priority.

Registration
The trial is registered at ClinicalTrials.gov, NCT01512615
Sequence-Tagged-Site (STS) Markers of Arbitrary Genes: Development, Characterization and Analysis of Linkage in Black Spruce
Authors: Perry Daniel J , Bousquet Jean 
Published: April 2021

Abstract
Sequence-tagged-site (STS) markers of arbitrary genes were investigated in black spruce [Picea mariana (Mill.) B.S.P.]. Thirty-nine pairs of PCR primers were used to screen diverse panels of haploid and diploid DNAs for variation that could be detected by standard agarose gel electrophoresis without further manipulation of amplification products. Codominant length polymorphisms were revealed at 15 loci. Three of these loci also had null amplification alleles as did 3 other loci that had no apparent product-length variation. Dominant length polymorphisms were observed at 2 other loci. Alleles of codominant markers differed in size by as little as 1 bp to as much as an estimated 175 bp with nearly all insertions/deletions found in noncoding regions. Polymorphisms at 3 loci involved large (33 bp to at least 114 bp) direct repeats and similar repeats were found in 7 of 51 cDNAs sequenced. Allelic segregation was in accordance with Mendelian inheritance and linkage was detected for 5 of 63 pairwise combinations of loci tested. Codominant STS markers of 12 loci revealed an average heterozygosity of 0.26 and an average of 2.8 alleles in a range-wide sample of 22 trees.
The Number of Self-Incompatibility Alleles in a Finite, Subdivided Population
Authors: Schierup Mikkel Heide 
Published: April 2021

Abstract
The actual and effective number of gametophytic self-incompatibility alleles maintained at mutation-drift-selection equilibrium in a finite population subdivided as in the island model is investigated by stochastic simulations. The existing theory founded by Wright predicts that for a given population size the number of alleles maintained increases monotonically with decreasing migration as is the case for neutral alleles. The simulation results here show that this is not true. At migration rates above Nm = 0.01–0.1, the actual and effective number of alleles is lower than for an undivided population with the same number of individuals, and, contrary to Wright's theoretical expectation, the number of alleles is not much higher than for an undivided population unless Nm &lt; 0.001. The same pattern is observed in a model where the alleles display symmetrical overdominant selection. This broadens the applicability of the results to include proposed models for the major histocompatibility (MHC) loci. For a subdivided population over a large range of migration rates, it appears that the number of self-incompatibility alleles (or MHC-alleles) observed can provide a rough estimate of the total number of individuals in the population but it underestimates the neutral effective size of the subdivided population.
Isolation of New Arabidopsis Mutants With Enhanced Disease Susceptibility to Pseudomonas syringae by Direct Screening
Authors: Volko Sigrid M , Boller Thomas , Ausubel Frederick M 
Published: April 2021

Abstract
To identify plant defense components that are important in restricting the growth of virulent pathogens, we screened for Arabidopsis mutants in the accession Columbia (carrying the transgene BGL2-GUS) that display enhanced disease susceptibility to the virulent bacterial pathogen Pseudomonas syringae pv. maculicola (Psm) ES4326. Among six (out of a total of 11 isolated) enhanced disease susceptibility (eds) mutants that were studied in detail, we identified one allele of the previously described npr1/nim1/sai1 mutation, which is affected in mounting a systemic acquired resistance response, one allele of the previously identified EDS5 gene, and four EDS genes that have not been previously described. The six eds mutants studied in detail (npr1-4, eds5-2, eds10-1, eds11-1, eds12-1, and eds13-1) displayed different patterns of enhanced susceptibility to a variety of phytopathogenic bacteria and to the obligate biotrophic fungal pathogen Erysiphe orontii, suggesting that particular EDS genes have pathogen-specific roles in conferring resistance. All six eds mutants retained the ability to mount a hypersensitive response and to restrict the growth of the avirulent strain Psm ES4326/avrRpt2. With the exception of npr1-4, the mutants were able to initiate a systemic acquired resistance (SAR) response, although enhanced growth of Psm ES4326 was still detectable in leaves of SAR-induced plants. The data presented here indicate that eds genes define a variety of components involved in limiting pathogen growth, that many additional EDS genes remain to be discovered, and that direct screens for mutants with altered susceptibility to pathogens are helpful in the dissection of complex pathogen response pathways in plants.
cot1: A Regulator of Arabidopsis Trichome Initiation
Authors: Szymanski Daniel B , Klis Daniel A , Larkin John C , Marks M David 
Published: April 2021

Abstract
In Arabidopsis, the timing and spatial arrangement of trichome initiation is tightly regulated and requires the activity of the GLABROUS1 (GL1) gene. The COTYLEDON TRICHOME 1 (COT1) gene affects trichome initiation during late stages of leaf development and is described in this article. In the wild-type background, cot1 has no observable effect on trichome initiation. GL1 overexpression in wild-type plants leads to a modest number of ectopic trichomes and to a decrease in trichome number on the adaxial leaf surface. The cot1 mutation enhances GL1-overexpression-dependent ectopic trichome formation and also induces increased leaf trichome initiation. The expressivity of the cot1 phenotype is sensitive to cot1 and 35S::GL1 gene dosage, and the most severe phenotypes are observed when cot1 and 35S::GL1 are homozygous. The COT1 locus is located on chromosome 2 15.3 cM north of er. Analysis of the interaction between cot1, try, and 35S::GL1 suggests that COT1 is part of a complex signal transduction pathway that regulates GL1-dependent adoption of the trichome cell fate.
A Genetic Screen for Modifiers of UFO Meristem Activity Identifies Three Novel FUSED FLORAL ORGANS Genes Required for Early Flower Development in Arabidopsis
Authors: Levin Joshua Z , Fletcher Jennifer C , Chen Xuemei , Meyerowitz Elliot M 
Published: April 2021

Abstract
In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s)acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.
Major Chromosomal Rearrangements Induced by T-DNA Transformation in Arabidopsis
Authors: Nacry Philippe , Camilleri Christine , Courtial Béatrice , Caboche Michel , Bouchez David 
Published: April 2021

Abstract
We show that major chromosomal rearrangements can occur upon T-DNA transformation of Arabidopsis thaliana. In the ACL4 line, two T-DNA insertion loci were found; one is a tandem T-DNA insert in a head-to-head orientation, and the other is a truncated insert with only the left part of the T-region. The four flanking DNA regions were isolated and located on the Arabidopsis chromosomes; for both inserts, one side of the T-DNA maps to chromosome 2, whereas the other side maps to chromosome 3. Both chromosome 3 flanking regions map to the same location, despite a 1.4-kb deletion at this point, whereas chromosome 2 flanking regions are located 40 cM apart on the bottom arm of chromosome 2. These results strongly suggest a reciprocal translocation between chromosomes 2 and 3, with the breakpoints located at the T-DNA insertion sites. The interchanged fragments roughly correspond to the 20-cM distal ends of both chromosomes. Moreover, a large inversion, spanning 40 cM on the genetic map, occurs on the bottom arm of chromosome 2. This was confirmed by genetic analyses that demonstrated a strong reduction of recombination in the inverted region. Models for T-DNA integration and the consequences for T-DNA tagging are discussed in light of these results.
Potential Retroviruses in Plants: Tat1 Is Related to a Group of Arabidopsis thaliana Ty3/gypsy Retrotransposons That Encode Envelope-Like Proteins
Authors: Wright David A , Voytas Daniel F 
Published: April 2021

Abstract
Tat1 was originally identified as an insertion near the Arabidopsis thaliana SAM1 gene. We provide evidence that Tat1 is a retrotransposon and that previously described insertions are solo long terminal repeats (LTRs) left behind after the deletion of coding regions of full-length elements. Three Tat1 insertions were characterized that have retrotransposon features, including a primer binding site complementary to an A. thaliana asparagine tRNA and an open reading frame (ORF) with ~44% amino acid sequence similarity to the gag protein of the Zea mays retrotransposon Zeon-1. Tat1 elements have large, polymorphic 3′ noncoding regions that may contain transduced DNA sequences; a 477-base insertion in the 3′ noncoding region of the Tat1-3 element contains part of a related retrotransposon and sequences similar to the nontranslated leader sequence of AT-P5C1, a gene for pyrroline-5-carboxylate reductase. Analysis of DNA sequences generated by the A. thaliana genome project identified 10 families of Ty3/gypsy retrotransposons, which share up to 51 and 62% amino-acid similarity to the ORFs of Tat1 and the A. thaliana Athila element, respectively. Phylogenetic analyses resolved the plant Ty3/gypsy elements into two lineages, one of which includes homologs of Tat1 and Athila. Four families of A. thaliana elements within the Tat/Athila lineage encode a conserved ORF after integrase at a position occupied by the envelope gene in retroviruses and in some insect Ty3/gypsy retrotransposons. Like retroviral envelope genes, this ORF encodes a transmembrane domain and, in some insertions, a putative secretory signal sequence. This suggests that Tat/Athila retrotransposons may produce enveloped virions and may be infectious.
Analysis of Natural Allelic Variation at Flowering Time Loci in the Landsberg erecta and Cape Verde Islands Ecotypes of Arabidopsis thaliana
Authors: Alonso-Blanco Carlos , El-Assal Salah El-Din , Coupland George , Koornneef Maarten 
Published: April 2021

Abstract
We have analyzed the flowering behavior of two Arabidopsis ecotypes: the laboratory strain Landsberg erecta (Ler) and an ecotype from the tropical Cape Verde Islands (Cvi). They differ little in their flowering phenotypes and in their responses to photoperiod length changes and to vernalization treatment. However, segregating populations derived from crosses between them showed a much larger variation. An approach of quantitative trait locus (QTL) mapping in recombinant inbred lines (RILs) grown under three environments differing in day-length and/or vernalization treatment has been used to detect and locate flowering loci. Four main QTLs were identified, designated early day-length insensitive (EDI), flowering F, G, and H (FLF, FLG, and FLH, respectively), to which most of the flowering behavior differences could be attributed. To further characterize the individual loci, near isogenic lines were constructed by introgressing Cvi early alleles of EDI and FLH into the Ler genetic background. EDI-Cvi alleles produce earliness under both long- and short-day photoperiods, rendering Ler plants almost day-length neutral. In addition, RILs were selected to analyze FLF and FLG. These loci interact epistatically and RILs carrying late alleles at FLF and FLG were very responsive to vernalization and showed an increased response to photoperiod length changes. The possible role of these loci for the control of flowering is discussed in the context of the current Arabidopsis model.
Multiple Recombination Events Maintain Sequence Identity Among Members of the Nitrogenase Multigene Family in Rhizobium etli
Authors: Rodríguez César , Romero David 
Published: April 2021

Abstract
A distinctive characteristic of the Rhizobium genome is the frequent finding of reiterated sequences, which often constitute multigene families. Interestingly, these families usually maintain a high degree of nucleotide sequence identity. It is commonly assumed that apparent gene conversion between reiterated elements might lead to concerted variation among members of a multigene family. However, the operation of this mechanism has not yet been demonstrated in the Rhizobiaceae. In this work, we employed different genetic constructions to address the role of apparent gene conversion as a homogenizing mechanism between members of the plasmid-located nitrogenase multigene family in Rhizobium etli. Our results show that a 28-bp insertion into one of the nitrogenase reiterations can be corrected by multiple recombination events, including apparent gene conversion. The correction process was dependent on the presence of both a wild-type recA gene and wild-type copies of the nitrogenase reiterations. Frequencies of apparent gene conversion to the wild-type nitrogenase reiterations were the same when the insertion to be corrected was located either in cis or in trans, indicating that this event frequently occurs through intermolecular interactions. Interestingly, a high frequency of multiple crossovers was observed, suggesting that these large plasmid molecules are engaging repeatedly in recombination events, in a situation akin to phage recombination or recombination among small, high-copy number plasmids.