1,463 research outputs found

    Unraveling the Mysteries of Galaxy Clusters: Recurrent Inference Deconvolution of X-ray Spectra

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    In the realm of X-ray spectral analysis, the true nature of spectra has remained elusive, as observed spectra have long been the outcome of convolution between instrumental response functions and intrinsic spectra. In this study, we employ a recurrent neural network framework, the Recurrent Inference Machine (RIM), to achieve the high-precision deconvolution of intrinsic spectra from instrumental response functions. Our RIM model is meticulously trained on cutting-edge thermodynamic models and authentic response matrices sourced from the Chandra X-ray Observatory archive. Demonstrating remarkable accuracy, our model successfully reconstructs intrinsic spectra well below the 1-sigma error level. We showcase the practical application of this novel approach through real Chandra observations of the galaxy cluster Abell 1550 - a vital calibration target for the recently launched X-ray telescope, XRISM. This work marks a significant stride in the domain of X-ray spectral analysis, offering a promising avenue for unlocking hitherto concealed insights into spectra.Comment: NeurIPS 2023 ML4PS accepted conference abstrac

    White matter integrity of contralesional and transcallosal tracts may predict response to upper limb task-specific training in chronic stroke

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    OBJECTIVE: To investigate white matter (WM) plasticity induced by intensive upper limb (UL) task specific training (TST) in chronic stroke. METHODS: Diffusion tensor imaging data and UL function measured by the Action Research Arm Test (ARAT) were collected in 30 individuals with chronic stroke prior to and after intensive TST. ANOVAs tested the effects of training on the entire sample and on the Responders [ΔARAT ≥ 5.8, N = 13] and Non-Responders [ΔARAT \u3c 5.8, N = 17] groups. Baseline fractional anisotropy (FA) values were correlated with ARATpost TST controlling for baseline ARAT and age to identify voxels predictive of response to TST. RESULTS: While ARAT scores increased following training (p \u3c 0.0001), FA changes within major WM tracts were not significant at p \u3c 0.05. In the Responder group, larger baseline FA of both contralesional (CL) and transcallosal tracts predicted larger ARAT scores post-TST. Subcortical lesions and more severe damage to transcallosal tracts were more pronounced in the Non-Responder than in the Responder group. CONCLUSIONS: The motor improvements post-TST in the Responder group may reflect the engagement of interhemispheric processes not available to the Non-Responder group. Future studies should clarify differences in the role of CL and transcallosal pathways as biomarkers of recovery in response to training for individuals with cortical and subcortical stroke. This knowledge may help to identify sources of heterogeneity in stroke recovery, which is necessary for the development of customized rehabilitation interventions

    Visual Elements and Cognitive Biases Influence Interpretations of Trends in Scatter Plots

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    Visualizations are common methods to convey information but also increasingly used to spread misinformation. It is therefore important to understand the factors people use to interpret visualizations. In this paper, we focus on factors that influence interpretations of scatter plots, investigating the extent to which common visual aspects of scatter plots (outliers and trend lines) and cognitive biases (people's beliefs) influence perception of correlation trends. We highlight three main findings: outliers skew trend perception but exert less influence than other points; trend lines make trends seem stronger but also mitigate the influence of some outliers; and people's beliefs have a small influence on perceptions of weak, but not strong correlations. From these results we derive guidelines for adjusting visual elements to mitigate the influence of factors that distort interpretations of scatter plots. We explore how these guidelines may generalize to other visualization types and make recommendations for future studies.Comment: 18 pages, 6 figure, 2 table

    Transcriptional changes in Huntington disease identified using genome-wide expression profiling and cross-platform analysis

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    Evaluation of transcriptional changes in the striatum may be an effective approach to understanding the natural history of changes in expression contributing to the pathogenesis of Huntington disease (HD). We have performed genome-wide expression profiling of the YAC128 transgenic mouse model of HD at 12 and 24 months of age using two platforms in parallel: Affymetrix and Illumina. The data from these two powerful platforms were integrated to create a combined rank list, thereby revealing the identity of additional genes that proved to be differentially expressed between YAC128 and control mice. Using this approach, we identified 13 genes to be differentially expressed between YAC128 and controls which were validated by quantitative real-time PCR in independent cohorts of animals. In addition, we analyzed additional time points relevant to disease pathology: 3, 6 and 9 months of age. Here we present data showing the evolution of changes in the expression of selected genes: Wt1, Pcdh20 and Actn2 RNA levels change as early as 3 months of age, whereas Gsg1l, Sfmbt2, Acy3, Polr2a and Ppp1r9a RNA expression levels are affected later, at 12 and 24 months of age. We also analyzed the expression of these 13 genes in human HD and control brain, thereby revealing changes in SLC45A3, PCDH20, ACTN2, DDAH1 and PPP1R9A RNA expression. Further study of these genes may unravel novel pathways contributing to HD pathogenesis. DDBJ/EMBL/GenBank accession no: GSE1967

    Individualized precision targeting of dorsal attention and default mode networks with rTMS in traumatic brain injury-associated depression

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    At the group level, antidepressant efficacy of rTMS targets is inversely related to their normative connectivity with subgenual anterior cingulate cortex (sgACC). Individualized connectivity may yield better targets, particularly in patients with neuropsychiatric disorders who may have aberrant connectivity. However, sgACC connectivity shows poor test-retest reliability at the individual level. Individualized resting-state network mapping (RSNM) can reliably map inter-individual variability in brain network organization. Thus, we sought to identify individualized RSNM-based rTMS targets that reliably target the sgACC connectivity profile. We used RSNM to identify network-based rTMS targets in 10 healthy controls and 13 individuals with traumatic brain injury-associated depression (TBI-D). These RSNM targets were compared with consensus structural targets and targets based on individualized anti-correlation with a group-mean-derived sgACC region ( sgACC-derived targets ). The TBI-D cohort was also randomized to receive active (n = 9) or sham (n = 4) rTMS to RSNM targets with 20 daily sessions of sequential high-frequency left-sided stimulation and low-frequency right-sided stimulation. We found that the group-mean sgACC connectivity profile was reliably estimated by individualized correlation with default mode network (DMN) and anti-correlation with dorsal attention network (DAN). Individualized RSNM targets were thus identified based on DAN anti-correlation and DMN correlation. These RSNM targets showed greater test-retest reliability than sgACC-derived targets. Counterintuitively, anti-correlation with the group-mean sgACC connectivity profile was also stronger and more reliable for RSNM-derived targets than for sgACC-derived targets. Improvement in depression after RSNM-targeted rTMS was predicted by target anti-correlation with the portions of sgACC. Active treatment also led to increased connectivity within and between the stimulation sites, the sgACC, and the DMN. Overall, these results suggest that RSNM may enable reliable individualized rTMS targeting, although further research is needed to determine whether this personalized approach can improve clinical outcomes

    DA NÃO INCIDÊNCIA DE ISS SOBRE ATIVIDADES-MEIO NA INDÚSTRIA DO ARROZ: UMA ANÁLISE NORMATIVISTA E INSTITUCIONAL

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    O presente artigo tem por objeto a análise da tributação das atividades-meio na indústria do arroz pelo imposto sobre serviços de qualquer natureza (ISS). O estudo foi realizado sob as perspectivas normativista e institucional. Em primeiro lugar, examinaram-se a Constituição Federal, a legislação, a literatura especializada e a jurisprudência dos Tribunais sobre o assunto. Posteriormente, avaliou-se os efeitos institucionais promovidos pela possibilidade de tributação pelo ISS das referidas atividades na agroindústria orizícola, que restou materializada por autuações fiscais municipais e discutida em processos judiciais perante a Justiça Estadual do Rio Grande do Sul

    ACORDOS DE CONFIDENCIALIDADE (NDA) EM STARTUPS

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    O presente artigo contempla análise jurídica sobre os acordos de confidencialidade firmados no âmbito das startups, mediante o exame dos seus aspectos normativos e pragmáticos. O estudo abrange, de um lado, o quadro das regras positivas vigentes com relevância para a matéria e a jurisprudência dos tribunais pátrios a respeito das principais questões envolvendo contratos de confidencialidade. De outro lado, versam-se, simultaneamente, sobre as repercussões práticas, as consequências, para o mercado e os agentes envolvidos nestas relações, tais como empreendedores, investidores, funcionários e parceiros comerciais

    In vivo cell-autonomous transcriptional abnormalities revealed in mice expressing mutant huntingtin in striatal but not cortical neurons

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    Huntington's disease (HD), caused by a CAG repeat expansion in the huntingtin (HTT) gene, is characterized by abnormal protein aggregates and motor and cognitive dysfunction. Htt protein is ubiquitously expressed, but the striatal medium spiny neuron (MSN) is most susceptible to dysfunction and death. Abnormal gene expression represents a core pathogenic feature of HD, but the relative roles of cell-autonomous and non-cell-autonomous effects on transcription remain unclear. To determine the extent of cell-autonomous dysregulation in the striatum in vivo, we examined genome-wide RNA expression in symptomatic D9-N171-98Q (a.k.a. DE5) transgenic mice in which the forebrain expression of the first 171 amino acids of human Htt with a 98Q repeat expansion is limited to MSNs. Microarray data generated from these mice were compared with those generated on the identical array platform from a pan-neuronal HD mouse model, R6/2, carrying two different CAG repeat lengths, and a relatively high degree of overlap of changes in gene expression was revealed. We further focused on known canonical pathways associated with excitotoxicity, oxidative stress, mitochondrial dysfunction, dopamine signaling and trophic support. While genes related to excitotoxicity, dopamine signaling and trophic support were altered in both DE5 and R6/2 mice, which may be either cell autonomous or non-cell autonomous, genes related to mitochondrial dysfunction, oxidative stress and the peroxisome proliferator-activated receptor are primarily affected in DE5 transgenic mice, indicating cell-autonomous mechanisms. Overall, HD-induced dysregulation of the striatal transcriptome can be largely attributed to intrinsic effects of mutant Htt, in the absence of expression in cortical neuron

    ACORDOS DE CONFIDENCIALIDADE (NDA) EM STARTUPS

    Get PDF
    O presente artigo contempla análise jurídica sobre os acordos de confidencialidade firmados no âmbito das startups, mediante o exame dos seus aspectos normativos e pragmáticos. O estudo abrange, de um lado, o quadro das regras positivas vigentes com relevância para a matéria e a jurisprudência dos tribunais pátrios a respeito das principais questões envolvendo contratos de confidencialidade. De outro lado, versam-se, simultaneamente, sobre as repercussões práticas, as consequências, para o mercado e os agentes envolvidos nestas relações, tais como empreendedores, investidores, funcionários e parceiros comerciais
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