Binary black hole mergers from field triples: properties, rates and the impact of stellar evolution

We consider the formation of binary black hole mergers through the evolution of field massive triple stars. In this scenario, favorable conditions for the inspiral of a black hole binary are initiated by its gravitational interaction with a distant companion, rather than by a common-envelope phase invoked in standard binary evolution models. We use a code that follows self-consistently the evolution of massive triple stars, combining the secular triple dynamics (Lidov-Kozai cycles) with stellar evolution. After a black hole triple is formed, its dynamical evolution is computed using either the orbit-averaged equations of motion, or a high-precision direct integrator for triples with weaker hierarchies for which the secular perturbation theory breaks down. Most black hole mergers in our models are produced in the latter non-secular dynamical regime. We derive the properties of the merging binaries and compute a black hole merger rate in the range (0.3- 1.3) Gpc^{-3}yr^{-1}, or up to ~2.5Gpc^{-3}yr^{-1} if the black hole orbital planes have initially random orientation. Finally, we show that black hole mergers from the triple channel have significantly higher eccentricities than those formed through the evolution of massive binaries or in dense star clusters. Measured eccentricities could therefore be used to uniquely identify binary mergers formed through the evolution of triple stars. While our results suggest up to ~10 detections per year with Advanced-LIGO, the high eccentricities could render the merging binaries harder to detect with planned space based interferometers such as LISA.Comment: Accepted for publication in ApJ. 10 pages, 6 figure

VISUEL - A Web Dynamic Dashboard for DataVisualization

Data visualization aims to explore and analyze data quickly, interactively, and intuitively using visual representations. Faced with the constant growth of data in terms of volume and diversity, visualization techniques must confront the challenge of dealing with increasingly large datasets in terms of representation, interaction, and performance. Therefore, these techniques must be able to effectively convey the characteristics of the information space and inspire discovery.In this article, we present VISUEL, a web dynamic dashboard for data visualization. VISUEL supports multiple coordinated views, integrating visualization techniques such as scatter plots, parallel coordinates, and box plots, and interactive schematic maps to represent information enriched with spatial references.VISUEL is fully interactive, supporting traditional interactions like filtering, selection, brushing and linking, and zooming, among others. It also allows the user to configure the visual representation of their data, by selecting the color and shape of the representations.We illustrate the usefulness of this tool using real-life data related to the wine industry in Argentina. Important aspects of our case study are discovered through the construction and analysis of multiple views.Fil: Antonini, Antonella Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Ganuza, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Castro, Silvia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentin

The Neural Correlates of Spatial and Object Working Memory in Elderly and Parkinson’s Disease Subjects

This fMRI study deals with the neural correlates of spatial and objects working memory (SWM and OWM) in elderly subjects (ESs) and idiopathic Parkinson’s disease (IPD). Normal aging and IPD can be associated with a WM decline. In IPD population, some studies reported similar SWM and OWM deficits; others reported a greater SWM than OWM impairment. In the present fMRI research, we investigated whether compensated IPD patients and elderly subjects with comparable performance during the execution of SWM and OWM tasks would present differences in WM-related brain activations. We found that the two groups recruited a prevalent left frontoparietal network when performing the SWM task and a bilateral network during OWM task execution. More specifically, the ESs showed bilateral frontal and subcortical activations in SWM, at difference with the IPD patients who showed a strict left lateralized network, consistent with frontostriatal degeneration in IPD. The overall brain activation in the IPD group was more extended as number of voxels with respect to ESs, suggesting underlying compensatory mechanisms. In conclusion, notwithstanding comparable WM performance, the two groups showed consistencies and differences in the WM activated networks. The latter underline the compensatory processes of normal typical and pathological aging

VISUEL: un tablero dinámico web para la visualización de datos

Data visualization aims to explore and analyze data quickly, interactively, and intuitively using visual representations. Faced with the constant growth of data in terms of volume and diversity, visualization techniques must confront the challenge of dealing with increasingly large datasets in terms of representation, interaction, and performance. Therefore, these techniques must be able to effectively convey the characteristics of the information space and inspire discovery. In this article, a web dynamic dashboard for data visualization called VISUEL is presented. VISUEL supports multiple coordinated views, integrating visualization techniques such as scatterplots, parallel coordinates, and box plots, and interactive schematic maps to represent information enriched with spatial references. VISUEL is fully interactive, supporting traditional interactions like filtering, selection, brushing and linking, and zooming, among others. It also allows the user to configure the visual representation of their data, by selecting the color and shape of the representations. The usefulness of this tool is illustrated using real-life dataset related to the wine industry in Argentina. Important aspects of the case study are discovered through the construction and analysis of multiple views.La visualización de datos tiene como objetivo explorar y analizar los datos de forma rápida, interactiva e intuitiva mediante representaciones visuales. Ante el constante crecimiento de los datos en términos de volumen y diversidad, las técnicas de visualización deben afrontar el desafío de lidiar con conjuntos de datos cada vez más grandes en términos de representación, interacción y desempeño. Por lo tanto, estas técnicas deben ser capaces de transmitir de manera efectiva las características del espacio de información e inspirar el descubrimiento. En este artículo, se presenta un tablero web dinámico para la visualización de datos llamado VISUEL. VISUEL admite múltiples vistas coordinadas, integrando técnicas de visualización como diagramas de dispersión, coordenadas paralelas, diagramas de caja, y mapas esquemáticos interactivos para representar información enriquecida con referencias espaciales. VISUEL es totalmente interactivo y admite interacciones tradicionales como filtrado, selección, brushing and linking, y zoom, entre otras. También permite al usuario configurar la representación visual de sus datos, seleccionando el color y la forma de las representaciones. La utilidad de esta herramienta se ilustra utilizando datos reales relacionados con la industria del vino en Argentina. Se descubren aspectos importantes del caso de estudio mediante la construcción y el análisis de múltiples vistas.Facultad de Informátic

YAP contributes to DNA methylation remodeling upon mouse embryonic stem cell differentiation

The Yes-associated protein YAP, one of the major effectors of the Hippo pathway together with its related protein TAZ, mediates a range of cellular processes from proliferation and death to morphogenesis. YAP and TAZ regulate a large number of target genes, acting as co-activators of DNA-binding transcription factors or as negative regulators of transcription by interacting with the nucleosome remodeling and histone deacetylase complexes. YAP is expressed in self-renewing embryonic stem cells (ESCs), although it is still debated whether it plays any crucial roles in the control of either stemness or differentiation. Here we show that the transient downregulation of YAP in mouse ESCs perturbs cellular homeostasis, leading to the inability to differentiate properly. Bisulfite genomic sequencing revealed that this transient knockdown caused a genome-wide alteration of the DNA methylation remodeling that takes place during the early steps of differentiation, suggesting that the phenotype we observed might be due to the dysregulation of some of the mechanisms involved in regulation of ESC exit from pluripotency. By gene expression analysis we identified two molecules which could have a role in the altered genome-wide methylation profile: the long non-coding RNA Ephemeron, whose rapid upregulation is crucial for ESCs transition into epiblast, and the methyltransferase-like protein Dnmt3l, which, during the embryo development, cooperates with Dnmt3a and Dnmt3b to contribute to the de novo DNA methylation that governs early steps of ESC differentiation. These data suggest a new role for YAP in the governance of the epigenetic dynamics of exit from pluripotency

Quantum dots labelling allows detection of the homing of mesenchymal stem cells administered as immunomodulatory therapy in an experimental model of pancreatic islets transplantation

Cell transplantation is considered a promising therapeutic approach in several pathologies but still needs innovative and non-invasive imaging technologies to be validated. The use of mesenchymal stem cells (MSCs) attracts major interest in clinical transplantation thanks to their regenerative properties, low immunogenicity and ability to regulate immune responses. In several animal models, MSCs are used in co-transplantation with pancreatic islets (PIs) for the treatment of type I diabetes, supporting graft survival and prolonging normal glycaemia levels. In this study we investigated the homing of systemically administered MSCs in a rat model of pancreatic portal vein transplantation. MSCs labelled with quantum dots (Qdots) were systemically injected by tail vein and monitored by optical fluorescence imaging. The fluorescence signal of the liver in animals co-transplanted with MSCs and PIs was significantly higher than in control animals in which MSCs alone were transplanted. By using magnetic labelling of PIs, the homing of PIs into liver was independently confirmed. These results demonstrate that MSCs injected in peripheral blood vessels preferentially accumulate into liver when PIs are transplanted in the same organ. Moreover, we prove that bimodal MRI-fluorescence imaging allows specific monitoring of the fate of two types of cells

Serum neurofilament light chain: a promising early diagnostic biomarker for hereditary transthyretin amyloidosis?

Background and purpose: Hereditary transthyretin amyloidosis (ATTRv) is a life-threatening disease caused by mutations in the gene encoding transthyretin (TTR). The recent therapeutic advances have underlined the importance of easily accessible, objective biomarkers of both disease onset and progression. Preliminary evidence suggests a potential role in this respect for neurofilament light chain (NfL). In this study, the aim was to determine serum NfL (sNfL) levels in a late-onset ATTRv population and evaluate whether it might represent a reliable biomarker of disease onset (i.e., 'conversion' from the asymptomatic status to symptomatic disease in TTR mutation carriers). Methods: In all, 111 individuals harbouring a pathogenic TTR variant (61 symptomatic ATTRv patients and 50 presymptomatic carriers) were consecutively enrolled. Fifty healthy volunteers were included as the control group. Ella™ apparatus was used to assess sNfL levels. Results: Serum NfL levels were increased in ATTRv patients compared to both presymptomatic carriers and healthy controls, whilst not differing between carriers and healthy controls. An sNfL cut-off of 37.10 pg/mL could discriminate between asymptomatic and symptomatic individuals with high diagnostic accuracy (area under the curve 0.958; p < 0.001), sensitivity (81.4%) and specificity (100%). Conclusions: Serum NfL seems to be a promising biomarker of peripheral nerve involvement in ATTRv amyloidosis and might become a reliable, objective measure to detect the transition from the presymptomatic stage to the onset of symptomatic disease. Further longitudinal studies are needed to confirm such a role and determine whether it could equally represent a biomarker of disease progression and response to therapy