49,558 research outputs found

    Direct observations of the atomic-molecular phase transition in the Milky Way's nuclear wind

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    Hundreds of high-velocity atomic gas clouds exist above and below the Galactic Centre, with some containing a molecular component. However, the origin of these clouds in the Milky Way's wind is unclear. This paper presents new high-resolution MeerKAT observations of three atomic gas clouds and studies the relationship between the atomic and molecular phases at ∼1\sim 1 pc scales. The clouds' atomic hydrogen column densities, NHIN_{\mathrm{HI}}, are less than a \mbox{few}\times 10^{20} cm−2^{-2}, but the two clouds closest to the Galactic Centre nonetheless have detectable CO emission. This implies the presence of H2_{2} at levels of NHIN_{\mathrm{HI}} at least a factor of ten lower than in the typical Galactic interstellar medium. For the cloud closest to the Galactic Centre, there is little correlation between the NHIN_{\mathrm{HI}} and the probability that it will harbour detectable CO emissions. In contrast, for the intermediate cloud, detectable CO is heavily biased toward the highest values of NHIN_{\mathrm{HI}}. The cloud most distant from the Galactic Centre has no detectable CO at similar NHIN_{\mathrm{HI}} values. Moreover, we find that the two clouds with detectable CO are too molecule-rich to be in chemical equilibrium, given the depths of their atomic shielding layers, which suggests a scenario whereby these clouds consist of pre-existing molecular gas from the disc that the Galactic wind has swept up, and that is dissociating into atomic hydrogen as it flows away from the Galaxy. We estimate that entrained molecular material of this type has a ∼few−10\sim \mathrm{few}-10 Myr lifetime before photodissociating.Comment: 11 pages, 6 figures, 2 tables. Submitted to MNRA

    Desarrollo de una batería de memoria semántica para pacientes con epilepsia del lóbulo temporal

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    La epilepsia focal más frecuente es aquella epilepsia cuyo foco epileptógeno está localizado en el lóbulo temporal medial y es secundaria a una esclerosis con atrofia de la región amígdalo-hipocámpica, con una red epileptógena que abarca la porción anterior del lóbulo temporal. En ocasiones los pacientes requieren de un tratamiento quirúrgico que incluye la resección unilateral de ambas regiones, tanto del polo anterior, como del complejo amígdala-hipocampo. Estas estructuras han demostrado tener gran importancia para el procesamiento de la memoria semántica (región anterotemporal) y episódica (región amígdalo-hipocámpica), por lo que los pacientes que son sometidos a esta intervención suelen presentar quejas cognitivas relacionadas con ambos tipos de memoria. Sin embargo, parece que las evaluaciones neuropsicológicas que realizamos de forma rutinaria en las diferentes Unidades de Epilepsia no son capaces de detectar todos los problemas cognitivos que ocurren en estos pacientes ya que, a pesar de las dificultades expresadas por estos, las evaluaciones no muestran alteraciones. La hipótesis principal del presente trabajo es que estas quejas se deben a tipos de memoria que no están incluidos en las pruebas neuropsicológicas actuales y, por tanto, no somos capaces de identificar bien sus problemas. En primer lugar, se propone que la memoria semántica está afectada, pero solamente para palabras de baja frecuencia de uso en la vida diaria, no analizadas en las evaluaciones convencionales actuales. En segundo lugar, otros problemas no objetivados se deben a un problema de la memoria de consolidación, medida como olvido a largo plazo acelerado que se detecta cuando se amplia el periodo de evaluación del recuerdo. Además, estas alteraciones van a manifestarse con mayor intensidad en pacientes cuyo foco epileptógeno está localizado en el lóbulo temporal izquierdo. Los objetivos fundamentales de este trabajo son evaluar en pacientes con epilepsia del lóbulo temporal medial intervenidos quirúrgicamente mediante lobectomía temporal anterior con amigdalohipocampectomía la presencia de alteraciones de la memoria verbal tanto semántica como episódica, así como conocer su valor lateralizador según el hemisferio afectado. El estudio se basó en la comparación de pacientes con epilepsia del lóbulo temporal (ELT) tratados con lobectomía temporal anterior con amigdalohipocampectomía con un grupo control de personas sanas, comparables respecto a edad, nivel educativo y coeficiente intelectual (CI). Las pruebas de memoria semántica mostraron que únicamente los pacientes con ELT izquierda tenían alteraciones, especialmente para ítems de baja frecuencia y tanto en tares de expresión como de comprensión verbal. Asimismo, el tiempo de reacción fue mayor en el grupo de pacientes con ELT izquierda para todos los ítems y únicamente para las palabras o conceptos de baja frecuencia en aquellos con ELT derecha. Además, se incluyó una prueba de memoria episódica estándar (RAVLT) que en lugar de restringir la evaluación a 30 minutos, se evaluó a 7 días para medir el olvido a largo plazo. Los resultados mostraron que los dos grupos de pacientes, tanto los de ELT izquierda como aquellos con ELT derecha, desarrollaron olvido a largo plazo. Por último los resultados mostraron que la presencia de crisis epilépticas no afectó a la presencia de olvido a largo plazo acelerado

    Constraints on Incremental Assembly of Upper Crustal Igneous Intrusions, Mount Ellen, Henry Mountains, Utah

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    Magma systems within the shallow crust drive volcanic processes at the surface. Studying active magma systems directly poses significant difficulty but details of ancient magma systems can provide insight to modern systems. The ancient intrusions now exposed in the Henry Mountains of southern Utah provide an excellent opportunity to study the emplacement of igneous intrusions within the shallow crust. The five main intrusive centers of the Henry Mountains are Oligocene in age and preserve different stages in the development of an igneous system within the shallow crust. Recent studies worldwide have demonstrated that most substantial (> 0.5 km3) igneous intrusions in the shallow crust are incrementally assembled from multiple magma pulses. In the Henry Mountains, smaller component intrusions (< 0.5 km3) clearly demonstrate incremental assembly but an evaluation of incremental assembly for an entire intrusive center has yet to be performed. The Mount Ellen intrusive complex is the largest intrusive center (~ 100 km3, 15 – 20 km diameter) in the Henry Mountains. This thesis research provides constraints on the construction history and emplacement of Mount Ellen using a combination of multiple techniques, including fieldwork, whole-rock major and trace element geochemistry, anisotropy of magnetic susceptibility, and crystal size distribution analysis. Field work and anisotropy of magnetic susceptibility data suggest that Mount Ellen is a laccolith that in cross section is built a network of stacked igneous sheets. In map-view, the laccolith has an elliptical shape built from numerous igneous lobes radiating away from the central portion of the intrusion. Field observations suggest most lobes are texturally homogenous and likely emplaced from a single magma batch. Samples collected throughout Mount Ellen were divided into five groups based on a qualitative evaluation of texture. Possible distinctions between these textural groups were then tested using several different techniques. Geochemistry, anisotropy of magnetic susceptibility, and phenocryst crystal size distribution data are individually not sufficient to distinguish all five textural groups. However, limited datasets for two textures can be consistently distinguished using these techniques. These new results can be integrated with existing constraints to create a comprehensive model for the construction history of Mount Ellen. The intrusive center was constructed in approximately 1 million years at a time-averaged magma injection rate of 0.0004 km3 y-1. The laccolith geometry was built from a radiating network of stacked igneous sheets. The sheets are lobate in map-view (longer than they are wide) and were fed radially outward from a central feeder zone. These component intrusions were emplaced by a minimum of 5 texturally distinct magma pulses, with periods of little or no magmatism between sequential pulses

    The Neuroscience of Moral Judgment: Empirical and Philosophical Developments

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    We chart how neuroscience and philosophy have together advanced our understanding of moral judgment with implications for when it goes well or poorly. The field initially focused on brain areas associated with reason versus emotion in the moral evaluations of sacrificial dilemmas. But new threads of research have studied a wider range of moral evaluations and how they relate to models of brain development and learning. By weaving these threads together, we are developing a better understanding of the neurobiology of moral judgment in adulthood and to some extent in childhood and adolescence. Combined with rigorous evidence from psychology and careful philosophical analysis, neuroscientific evidence can even help shed light on the extent of moral knowledge and on ways to promote healthy moral development

    Tratamento cirúrgico de quilotórax : laqueação do ducto torácico e pericardiectomia subtotal por toracoscopia

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    Dissertação de Mestrado Integrado em Medicina Veterinária. Área Científica - ClínicaO quilotórax é uma doença pouco comum, com uma grande parte dos casos correspondendo a quilotórax idiopático. É de maior importância determinar a causa, se existente, no sentido de direcionar o tratamento para a mesma. No caso de quilotórax idiopático, o tratamento poderá ser médico ou cirúrgico, sendo que o segundo tem maior probabilidade de sucesso. Existem diversas técnicas descritas para tratamento cirúrgico de quilotórax. O objetivo do presente trabalho é o de reportar um caso cirúrgico de laqueação do ducto torácico e pericardiectomia subtotal por toracoscopia, relatando as dificuldades sentidas e o sucesso do procedimento, e analisando de forma detalhada a experiência. A abordagem consistiu na realização da laqueação do ducto torácico e pericardiectomia subtotal por toracoscopia após linfografia. Verificou-se ainda derrame durante 50 dias após a cirurgia. Após esse período, o animal apresentou-se livre de sinais clínicos durante mais de nove meses. A técnica foi realizada com sucesso, embora o caso apresente alguns aspectos com possíveis melhorias. A laqueação do ducto torácico e pericardiectomia subtotal são técnicas passíveis de ser realizadas através de métodos de mínima invasão, nos quais é necessário investir para permitir uma evolução e maior sensibilidade para o bem-estar animal.ABSTRACT - Chylothorax is an uncommon clinical situation, with most cases being classified as idiopathic. It is of major importance to determine the underlying cause of chylothorax, if it exists, in order to direct the treatment to that cause. If chylothorax is classified as idiopathic, both medical and surgical treatments are available, but surgical treatment has a higher chance of sucess. There are several techniques described for the surgical treatment of chylothorax. The objective of this study is to report a surgical case of thoracic duct ligation and subtotal pericardiectomy by thoracoscopy, reporting the difficulties experienced and the success of the procedure, and analyzing the experience in detail. The approach consisted of performing thoracic duct ligation and subtotal pericardiectomy by thoracoscopy, and lymphography was performed before the surgery. Effusion occurred for 50 days after surgery. After this period, the patient was free from clinical signs for more than nine months. The technique was successfully performed, although the case presents some aspects with possible improvements. Thoracic duct ligation and subtotal pericardiectomy are techniques that can be performed using minimally invasive methods, which should be endorsed and invested in, in order to contribute to animal welfareN/

    The MeerKAT Galaxy Cluster Legacy Survey: Survey overview and highlights

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    MeerKAT’s large number (64) of 13.5 m diameter antennas, spanning 8 km with a densely packed 1 km core, create a powerful instrument for wide-area surveys, with high sensitivity over a wide range of angular scales. The MeerKAT Galaxy Cluster Legacy Survey (MGCLS) is a programme of long-track MeerKAT L-band (900−1670 MHz) observations of 115 galaxy clusters, observed for ∼6−10 h each in full polarisation. The first legacy product data release (DR1), made available with this paper, includes the MeerKAT visibilities, basic image cubes at ∼8″ resolution, and enhanced spectral and polarisation image cubes at ∼8″ and 15″ resolutions. Typical sensitivities for the full-resolution MGCLS image products range from ∼3−5 μJy beam−1. The basic cubes are full-field and span 2° × 2°. The enhanced products consist of the inner 1.2° × 1.2° field of view, corrected for the primary beam. The survey is fully sensitive to structures up to ∼10′ scales, and the wide bandwidth allows spectral and Faraday rotation mapping. Relatively narrow frequency channels (209 kHz) are also used to provide H I mapping in windows of 0 < z < 0.09 and 0.19 < z < 0.48. In this paper, we provide an overview of the survey and the DR1 products, including caveats for usage. We present some initial results from the survey, both for their intrinsic scientific value and to highlight the capabilities for further exploration with these data. These include a primary-beam-corrected compact source catalogue of ∼626 000 sources for the full survey and an optical and infrared cross-matched catalogue for compact sources in the primary-beam-corrected areas of Abell 209 and Abell S295. We examine dust unbiased star-formation rates as a function of cluster-centric radius in Abell 209, extending out to 3.5 R 200. We find no dependence of the star-formation rate on distance from the cluster centre, and we observe a small excess of the radio-to-100 μm flux ratio towards the centre of Abell 209 that may reflect a ram pressure enhancement in the denser environment. We detect diffuse cluster radio emission in 62 of the surveyed systems and present a catalogue of the 99 diffuse cluster emission structures, of which 56 are new. These include mini-halos, halos, relics, and other diffuse structures for which no suitable characterisation currently exists. We highlight some of the radio galaxies that challenge current paradigms, such as trident-shaped structures, jets that remain well collimated far beyond their bending radius, and filamentary features linked to radio galaxies that likely illuminate magnetic flux tubes in the intracluster medium. We also present early results from the H I analysis of four clusters, which show a wide variety of H I mass distributions that reflect both sensitivity and intrinsic cluster effects, and the serendipitous discovery of a group in the foreground of Abell 3365

    Epilepsy Mortality: Leading Causes of Death, Co-morbidities, Cardiovascular Risk and Prevention

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    a reuptake inhibitor selectively prevents seizure-induced sudden death in the DBA/1 mouse model of sudden unexpected ... Bilateral lesions of the fastigial nucleus prevent the recovery of blood pressure following hypotension induced by&nbsp;..

    Using qualitative online methods to evaluate community responses to Covid19

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    This case study considers moving health promotion evaluation practice online to allow the continuation of data gathering safely in Covid19 and the implications of this for all of those involved; researchers and participants alike. We outline the methods that we used to conduct a commissioned evaluation online because of the Covid19 restrictions imposed in England at the time of our study. Evaluation is an activity that remains central to health promotion practice because it is concerned with assessing whether interventions are effective (Green and South 2006). This evaluation focused upon qualitatively assessing the Third Sector and community response to Covid19 across one city in the North of England. We aimed to use a people centered approach to our data collection to explore the impacts and outcomes arising from small grants awarded to different communities (young people, ethnically diverse groups, older people, Travelers, men) by capturing the importance of service user experiences in our work. We learned to be flexible, to consider the importance of offering a variety of mechanisms to facilitate participant involvement and to expand our ethical considerations because of the implications of online data gathering
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