659 research outputs found

    Interactions between energetic electrons and realistic whistler mode waves in the Jovian magnetosphere

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    The role of plasma waves in shaping the intense Jovian radiation belts is not well understood. In this study we use a realistic wave model based on an extensive survey from the Plasma Wave Investigation on the Galileo spacecraft to calculate the effect of pitch angle and energy diffusion on Jovian energetic electrons due to upper and lower band chorus. Two Earth-based models, the Full Diffusion Code and the Versatile Electron Radiation Belt code, are adapted to the case of the Jovian magnetosphere and used to resolve the interaction between chorus and electrons at L = 10. We also present a study of the sensitivity to the latitudinal wave coverage and initial electron distribution. Our analysis shows that the contribution to the electron dynamics from upper band chorus is almost negligible compared to that from lower band chorus. For 100 keV electrons, we observe that diffusion leads to redistribution of particles toward lower pitch angles with some particle loss, which could indicate that radial diffusion or interchange instabilities are important. For energies above >500 keV, an initial electron distribution based on observations is only weakly affected by chorus waves. Ideally, we would require the initial electron phase space density before transport takes place to assess the importance of wave acceleration, but this is not available. It is clear from this study that the shape of the electron phase space density and the latitudinal extent of the waves are important for both electron acceleration and loss

    Neurologic phenotype of Schimke immuno-osseous dysplasia and neurodevelopmental expression of SMARCAL1

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    Schimke immuno-osseous dysplasia (OMIM 242900) is an uncommon autosomal-recessive multisystem disease caused by mutations in SMARCAL1 (swi/snf-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), a gene encoding a putative chromatin remodeling protein. Neurologic manifestations identified to date relate to enhanced atherosclerosis and cerebrovascular disease. Based on a clinical survey, we determined that half of Schimke immuno-osseous dysplasia patients have a small head circumference, and 15% have social, language, motor, or cognitive abnormalities. Postmortem examination of 2 Schimke immuno-osseous dysplasia patients showed low brain weights and subtle brain histologic abnormalities suggestive of perturbed neuron-glial migration such as heterotopia, irregular cortical thickness, incomplete gyral formation, and poor definition of cortical layers. We found that SMARCAL1 is highly expressed in the developing and adult mouse and human brain, including neural precursors and neuronal lineage cells. These observations suggest that SMARCAL1 deficiency may influence brain development and function in addition to its previously recognized effect on cerebral circulation

    Caracterización por Espectrometría de Masas MALDI de Cucurbit[n]uriles (n = 6,7,8)

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    The characterization of a mixture of cucurbit[n]uril (n = 6,7,8) was carried out by MALDI MS (Matrix-assisted Laser Desorption/Ionization Mass Spectrometry Mass Spectrometry). The solid mixture of the titled compounds was synthesized as part of a research study involving supramolecular chemistry at the Departamento de Química e Ingeniería Química at USFQ. For the MALDI analysis, an appropriate procedure was implemented for sample preparation, which includes the effective dissolution of the solid mixture of cucurbit[n]uril in a solution of water and formic acid, and the addition of alpha-cyano-4-hydroxy cinamic acid as MALDI matrix (10g/l in 70:30 (v:v) of methanol: acetonitrile). In the sample preparation process for MALDI, other solvents were employed to try dissolving the cucurbit[n]uril mixture with poor results. The addition of formic acid to deionized water was important to achieve satisfactory dissolution of the cucurbit[n]uril compounds and to assure its compatibility with the matrix. To acquire the corresponding mass spectra, a MALDI-Time-of-Flight Mass Spectrometer (MALDI-TOF MS) was used, which was built in the Departamento de Física at EPN. The mass spectra of the detected cucurbit[n]uril ions were characterized by the presence of the single protonated peaks of three molecular species corresponding to n = 6,7,8 as inferred from their m/z values. Additionally, the mass spectra contained abundant peaks of the MALDI matrix in the mass region up to 500 Da. The mass spectra were satisfactorily internally calibrated with the help of multiple peaks of a PEG600 polymer that was introduced as an internal standard in the sample. The instrumental molecular mass resolution allowed for isotopical resolution over the whole mass range and the overall mass accuracy was about 0.1 %. The most intense signal among the cucurbit[n]uril peaks was assigned to the cucurbit[7]uril compound. A discussion is advanced to rationalize the observed molecular cucurbit[n]uril species under the used methodology.La caracterización de una mezcla de cucurbit[n]uriles (n = 6,7,8) se ha realizado por medio de espectrometría de masas con la técnica de ionización MALDI (Matrix-assisted Laser Desorption/Ionization). Los cucurbit[n]uriles fueron sintetizados como parte de una investigación de química supramolecular dentro del Departamento de Química e Ingeniería Química de la USFQ. Para el análisis con MALDI se ha introducido un procedimiento adecuado para la preparación de muestras, que incluye la disolución efectiva de la mezcla sólida de cucurbit[n]uriles en una solución de agua y ácido fórmico, y el uso del ácido alfa-ciano-4-hidroxi-cinámico como matriz MALDI, en una solución 10g/l en 70:30 (v:v) de metanol y acetronitrilo. En el proceso de preparación de muestras para MALDI se intentó utilizar otros solventes para el cucurbit[n]uril con pobres resultados. La adición del ácido fórmico al agua desionizada fue importante para lograr la correcta disolución del compuesto y asegurar su compatibilidad con la solución de matriz. Para obtener los espectros de masas correspondientes se utilizó un espectrómetro de masas de tiempo de vuelo MALDI (MALDI TOF-MS) construido en el Departamento de Física de la EPN. Los espectros de masa de los cucurbit[n]uriles se caracterizaron por la presencia de los iones protonados con una carga de las especies moleculares correspondientes a n = 6,7,8, según se infiere de los valores m/z medidos. Adicionalmente, los espectros de masa contuvieron picos abundantes de la matriz MALDI en la región de masas hasta 500 Da. Los espectros de masa se calibraron internamente de forma satisfactoria con la ayuda de os múltiples picos del polímero PEG600 que se introdujo como un estándar interno en las muestras. La resolución de masas instrumental permitió separar las componentes isotópicas a lo largo de todo el rango de masas y una precisión general en la detrminación de la masa de alrededor de 0.1 %. La señal más intensa entre los cucurbit[n]uriles se la asignó al compuesto cucurbit[7]uril. Se hace una corta discusión tendiente a racionalizar la observación de las especies observadas con nuestra metodología experimental

    Obesity and Fatty Acids Promote Mitochondrial Translocation of STAT3 Through ROS-Dependent Mechanisms

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    Obesity promotes the onset and progression of metabolic and inflammatory diseases such as type 2 diabetes. The chronic low-grade inflammation that occurs during obesity triggers multiple signaling mechanisms that negatively affect organismal health. One such mechanism is the persistent activation and mitochondrial translocation of STAT3, which is implicated in inflammatory pathologies and many types of cancers. STAT3 in the mitochondria (mitoSTAT3) alters electron transport chain activity, thereby influencing nutrient metabolism and immune response. PBMCs and CD4+ T cells from obese but normal glucose-tolerant (NGT) middle-aged subjects had higher phosphorylation of STAT3 on residue serine 727 and more mitochondrial accumulation of STAT3 than cells from lean subjects. To evaluate if circulating lipid overabundance in obesity is responsible for age- and sex-matched mitoSTAT3, cells from lean subjects were challenged with physiologically relevant doses of the saturated and monounsaturated fatty acids, palmitate and oleate, respectively. Fatty acid treatment caused robust accumulation of mitoSTAT3 in all cell types, which was independent of palmitate-induced impairments in autophagy. Co-treatment of cells with fatty acid and trehalose prevented STAT3 phosphorylation and mitochondrial accumulation in an autophagy-independent but cellular peroxide–dependent mechanism. Pharmacological blockade of mitoSTAT3 either by a mitochondria-targeted STAT3 inhibitor or ROS scavenging prevented obesity and fatty acid–induced production of proinflammatory cytokines IL-17A and IL-6, thus establishing a mechanistic link between mitoSTAT3 and inflammatory cytokine production

    The management of bronchus intermedius complications after lung transplantation: A retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Airway complications following lung transplantation remain a significant cause of morbidity and mortality. The management of bronchial complications in Bronchus Intermedius (BI) is challenging due to the location of right upper bronchus. The aim of this study was to analyze the results of BI Montgomery T-tube stent in a consecutive patients with lung transplantations.</p> <p>Methods</p> <p>Between January 2007 and December 2010, 132 lung transplantations were performed at Foch Hospital, Suresnes, France. All the patients who had BI Montgomery T-tube after lung transplantation were included in this retrospective study. The demographic and interventional data and also complications were recorded.</p> <p>Results</p> <p>Out of 132 lung transplant recipients, 12 patients (9 male and 3 female) were entered into this study. The indications for lung transplantation were: cystic fibrosis 8 (67%), emphysema 3 (25%), and idiopathic pulmonary fibrosis 1 (8%). Most of the patients (83%) had bilateral lung transplantation. The mean interval between lung transplantation and interventional bronchoscopy was 11.5 ± 9.8 (SD) months. There was bronchial stenosis at the level of BI in 7 patients (58.3%). The Montgomery T-tube number 10 was used in 9 patients (75%). There was statistically significant difference in Forced Expiratory Volume in one second (FEV1) before and after stent placement (p = 0.01). The most common complication after stent placement was migration (33%).</p> <p>Conclusion</p> <p>BI complications after lung transplantation are still a significant problem. Stenosis or malacia following lung transplantation could be well managed with modified Montgomery T-tube.</p

    Territorios Hidrosociales: una metodología para promover la seguridad hídrica ante el cambio climático a través de la gobernanza, visión y acción participativa

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    La gobernanza en territorios hidrosociales a partir de la participación ciudadana, el diálogo de saberes, y la confianza entre los actores territoriales es fundamental para garantizar una distribución justa y sostenible del agua. Este artículo presenta un enfoque metodológico para la promoción de la seguridad hídrica fundamentada en el fortalecimiento de la gobernanza del agua que permitan formalizar las aspiraciones de seguridad hídrica en la comunidad, la construcción de una visión y acciones estratégicas colectivas y concertadas. El enfoque integra conceptos pragmáticos y transdisciplinarios considerando sólo aquellos conceptos que proveen una explicación a partir de las perspectivas de actores independientemente de su disciplina, promueve la adaptación al cambio climático y la transformación hacia territorios sostenibles. La implementación de enfoques transdisciplinarios suele carecer de documentación, con este manuscrito se busca sistematizar como una oportunidad para promover la transparencia y la reproducibilidad de este tipo de iniciativas

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Observations of coincident EMIC wave activity and dusk-side energetic electron precipitation on 18-19 January 2013

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    Electromagnetic ion cyclotron (EMIC) waves have been suggested to be a cause of radiation belt electron loss to the atmosphere. Here simultaneous, magnetically conjugate measurements are presented of EMIC wave activity, measured at geosynchronous orbit and on the ground, and energetic electron precipitation, seen by the BARREL balloon campaign, on two consecutive days in January 2013. Multiple bursts of precipitation were observed on the dusk-side of the magnetosphere at the end of 18 Jan and again late on 19 Jan, concurrent with particle injections, substorm activity, and enhanced magnetospheric convection. The structure, timing, and spatial extent of the waves are compared to those of the precipitation during both days to determine when and where EMIC waves cause radiation belt electron precipitation. The conjugate measurements presented here provide observational support of the theoretical picture of dusk-side interaction of EMIC waves and MeV electrons leading to radiation belt loss
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