Ultra-fine dark matter structure in the Solar neighbourhood

The direct detection of dark matter on Earth depends crucially on its density and its velocity distribution on a milliparsec scale. Conventional N-body simulations are unable to access this scale, making the development of other approaches necessary. In this paper, we apply the method developed in Fantin et al. 2008 to a cosmologically-based merger tree, transforming it into a useful instrument to reproduce and analyse the merger history of a Milky Way-like system. The aim of the model is to investigate the implications of any ultra-fine structure for the current and next generation of directional dark matter detectors. We find that the velocity distribution of a Milky Way-like Galaxy is almost smooth, due to the overlap of many streams of particles generated by multiple mergers. Only the merger of a 10^10 Msun analyse can generate significant features in the ultra-local velocity distribution, detectable at the resolution attainable by current experiments.Comment: 9 pages, 6 figures, accepted for publication in MNRA

Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation

Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165–amino acid isoform of vascular endothelial growth factor A (VEGF-A165). NRP1 is also the receptor for the CendR peptides, a class of cell- and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A165, a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation

Terrain-Informed Self-Supervised Learning: Enhancing Building Footprint Extraction from LiDAR Data with Limited Annotations

Estimating building footprint maps from geospatial data is of paramount importance in urban planning, development, disaster management, and various other applications. Deep learning methodologies have gained prominence in building segmentation maps, offering the promise of precise footprint extraction without extensive post-processing. However, these methods face challenges in generalization and label efficiency, particularly in remote sensing, where obtaining accurate labels can be both expensive and time-consuming. To address these challenges, we propose terrain-aware self-supervised learning, tailored to remote sensing, using digital elevation models from LiDAR data. We propose to learn a model to differentiate between bare Earth and superimposed structures enabling the network to implicitly learn domain-relevant features without the need for extensive pixel-level annotations. We test the effectiveness of our approach by evaluating building segmentation performance on test datasets with varying label fractions. Remarkably, with only 1% of the labels (equivalent to 25 labeled examples), our method improves over ImageNet pre-training, showing the advantage of leveraging unlabeled data for feature extraction in the domain of remote sensing. The performance improvement is more pronounced in few-shot scenarios and gradually closes the gap with ImageNet pre-training as the label fraction increases. We test on a dataset characterized by substantial distribution shifts and labeling errors to demonstrate the generalizability of our approach. When compared to other baselines, including ImageNet pretraining and more complex architectures, our approach consistently performs better, demonstrating the efficiency and effectiveness of self-supervised terrain-aware feature learning

PLXNA1 and PLXNA3 cooperate to pattern the nasal axons that guide gonadotropin-releasing hormone neurons

Gonadotropin-releasing hormone (GnRH) neurons regulate puberty onset and sexual reproduction by secreting GnRH to activate and maintain the hypothalamic-pituitary-gonadal axis. During embryonic development, GnRH neurons migrate along olfactory and vomeronasal axons through the nose into the brain, where they project to the median eminence to release GnRH. The secreted glycoprotein SEMA3A binds its receptors neuropilin (NRP) 1 or NRP2 to position these axons for correct GnRH neuron migration, with an additional role for the NRP co-receptor PLXNA1. Accordingly, mutations in SEMA3A, NRP1, NRP2 and PLXNA1 have been linked to defective GnRH neuron development in mice and inherited GnRH deficiency in humans. Here, we show that only the combined loss of PLXNA1 and PLXNA3 phenocopied the full spectrum of nasal axon and GnRH neuron defects of SEMA3A knockout mice. Together with Plxna1, the human orthologue of Plxna3 should therefore be investigated as a candidate gene for inherited GnRH deficiency

Plxna1 and Plxna3 cooperate to pattern the nasal axons that guide gonadotropin-releasing hormone neurons

The gonadotropin releasing hormone (GnRH) neurons regulate puberty onset and sexual reproduction by secreting GnRH to activate and maintain the hypothalamic-pituitary gonadal axis. During embryonic development, GnRH neurons migrate along olfactory and vomeronasal axons through the nose into the brain, where they project to the median eminence to release GnRH. The secreted glycoprotein SEMA3A binds its receptors neuropilin (NRP) 1 or NRP2 to position these axons for correct GnRH neuron migration, with an additional role for the NRP co-receptor PLXNA1. Accordingly, mutations in SEMA3A, NRP1, NRP2 and PLXNA1 have been linked to defective GnRH neuron development in mice and inherited GnRH deficiency in humans. Here, we show that only the combined loss of PLXNA1 and PLXNA3 phenocopied the full spectrum of nasal axon and GnRH neuron defects of SEMA3A knockout mice. Together with Plxna1, the human ortholog of Plxna3 should therefore be investigated as a candidate gene for inherited GnRH deficiency

Geotecnologias e aprendizagem espacial em ambiente educacional: o mapeamento de nascentes utilizando técnicas de geoprocessamento por meio de softwares livres.

The headwaters of streams are extremely important to maintain the water sources and contribute to the permanent preservation areas (PPA) and hence with the ecosystems of any region. Thus this aspect were investigated by mapping using GIS techniques by free software. The data were validated by field research conducted by students of the 1st year of high school ? Escola Estadual de Ensino Médio Pedro Migliorini, located in the municipality of Monte Belo do Sul, Brazil. The objective of the study was to allow students to assess quantitatively and qualitatively the headwaters of the city, analyzing water usage, as well as the situation of the same as the environmental laws. Students were divided into work areas, conducted interviews with landowners in order to research on the consumption and use of water and what methods are used for the preservation of the spring on the property. To assess if the sources informed the owners comply with current legislation, GIS tools were employed and was generated a buffer of 50 meters (area corresponding to PPA) around the source. At the end of the study were located 427 points with the following observations: 1) 95 are used for human consumption, 2) 107 for animal consumption, 3) 145 have some protection; 4) 23 are in accordance with current legislation . 37 springs were not informed about the use

Screening for fmr1 expanded alleles in patients with autism spectrum disorders in Manaus, Northern Brazil

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by dynamic mutations of a CGG repetition segment in an X chromosome’s single gene. It is considered the leading hereditary cause of both Autism Spectrum Disorders and Intellectual Disability. Some authors suggest that all individuals diagnosed with some of these latter conditions to be clinically and molecularly trialled for FXS due to the high levels of comorbidity between both conditions and also due to the variable expressiveness of this syndrome. This study has focused on verifying the presence of FMR1 expanded alleles since there is a lack of information about this kind of mutation in autism patients from the northern region of Brazil. The presence of large alleles for this gene could offer new therapeutic or pharmacological methods for the treatment of these patients. Both the presence and the frequency of CGG expansions were verified in 90 autism males by molecular analysis. Four of them had intermediate alleles and four others presented premutated alleles. Premutation carriers are on the propensity of developing the late onset Fragile X-associated tremor/ataxia syndrome. No full mutation alleles were found. Further studies are necessary to obtain more accurate statistical data about this kind of dynamic mutation. © 2019, Academia Brasileira de Ciencias. All rights reserved

An update on methods for Sarcopenia Diagnosis: From bench to bedside

Sarcopenia has been recognized as an age-related syndrome characterized by low muscle mass, low muscle strength, and low physical performance that is associated with increased likelihood of adverse outcomes including falls, fractures, hospitalization, frailty and mortality. Therefore, it is necessary to identify the condition early for applying intervention and prevention of the disastrous consequences of sarcopenia if left untreated. Clinical definition and diagnostic criteria for sarcopenia have been developed in the last years and different tools have been proposed for screening subjects with sarcopenia, evaluating the muscle mass, the muscle strength and the physical performance. In this review we analyzed the diagnostic criteria of sarcopenia and examined the current assessment tools used for the diagnosis and screening of sarcopenia