Hypernovae as possible sources of Galactic positrons

INTEGRAL/SPI has recently observed a strong and extended emission resulting from electron-positron annihilation located in the Galactic center region, consistent with the Galactic bulge geometry, without any counterpart at high gamma-ray energies, nor in the 1809 keV $^{26}$Al decay line. In order to explain the rate of positron injection in the Galactic bulge, estimated to more than 10$^{43}$ s$^{-1}$, the most commonly considered positron injection sources are type Ia supernovae. However, SN Ia rate estimations show that those sources fall short to explain the observed positron production rate, raising a challenging question about the nature of the Galactic positron source. In this context, a possible source of Galactic positrons could be supernova events of a new type, as the recently observed SN2003dh/GRB030329, an exploding Wolf-Rayet star (type Ic supernova) associated with a hypernova/gamma-ray burst; the question about the rate of this kind of events remains open, but could be problematically low. In this paper, we explore the possibility of positron production and escape by such an event in the framework of an asymmetric model, in which a huge amount of $^{56}$Ni is ejected in a cone with a very high velocity; the ejected material becomes quickly transparent to positrons, which spread out in the interstellar medium.Comment: 8 pages, 2 figures. To appear in the Proceedings of the 5th INTEGRAL Workshop: "The INTEGRAL Universe", February 16-20, 2004, Munich, German

The mapping of organizations delivering mental health services in Nunavik Ungava Bay Area

RESUMO: Em Nunavik, nunca foi realizado um mapeamento completo dos serviços que incluem um hospital, centro de saúde local e organizações da comunidade que fornecem cuidados de saúde mental básicos ou mais avançados e serviços de apoio aos cuidados de saúde mental fornecidos e disponíveis em cada localidade da Costa Ungava. Esta pequisa é o primeiro mapeamento abrangente dos diferentes tipos de serviços fornecidos por diferentes organizações institucionais e não institucionais nesta área. Objetivos: os objetivos específicos da pesquisa deste projeto são os seguintes: 1. Mapeamento de organizações que forneçam cuidados de saúde mental e apoio aos cuidados de saúde mental a pessoas com mais de 18 anos na costa Nunavik Ungava 2. Mapeamento dos serviços disponíveis destas organizações 3. Mapeamento da disponibilidade destes serviços em cada localidade 4. Mapeamento da aliança institucional entre estas organizações e a configuração hospitalar regional Métodos: Todas as organizações de saúde mental na área geográfica foram contactadas e os dados reunidos foram classificados através do instrumento DESDE-LTC. Resultados: os resultados atingidos incluem: 1. Uma descrição classificativa dos serviços fornecidos para a saúde mental dos adultos 2. Uma imagem de mapeamento da continuidade dos serviços entre as organizações da comunidade, o nível de cuidados primários, o nível de cuidados secundários e o nível de cuidados terciários 3. Melhorias propostas na continuidade dos serviços. Conclusões: Ao identificar e descrever os serviços das organizações da comunidade, as nossas conclusões fornecem instrumentos para construir pontes de colaboração entre os cuidados de saúde mental institucionais, os recursos da comunidade e as necessidades da população.ABSTRACT: In Nunavik, a complete mapping including hospital, local health centre and the community organizations delivering basic or more advanced mental health care and mental health care support services delivered and available in each village of the Ungava Coast has never been done. This research is the first comprehensive mapping of the different kinds of services delivered by different institutional and non-institutional organizations in this area. Objectives: this project research more specific objectives are the following: 1. Mapping organizations delivering mental health care and mental health care support to people over 18 years old on the Nunavik Ungava coast 2. Mapping the services available from those organizations 3. Mapping the availability of those services in each village 4. Mapping the institutional alliance between those organizations and the regional hospital setting. Methods: All the mental health organizations in the geographical area were contacted and the data gathered classified using the DESDE-LTC instrument. Results: the results achieved include: 1. An appraisal description of services delivered in adult mental health 2. A mapping picture of the continuum of services between community organizations, primary care level, secondary care level and tertiary care level 3. Proposed improvements in the continuum of services. Conclusions: By identifying and describing the community organizations services, our findings give instruments to build collaborative bridges between the institutionalized mental health care, the community resources, and the population needs

Characterization of a Multi-User Indoor Positioning System Based on Low Cost Depth Vision (Kinect) for Monitoring Human Activity in a Smart Home

An increasing number of systems use indoor positioning for many scenarios such as asset tracking, health care, games, manufacturing, logistics, shopping, and security. Many technologies are available and the use of depth cameras is becoming more and more attractive as this kind of device becomes affordable and easy to handle. This paper contributes to the effort of creating an indoor positioning system based on low cost depth cameras (Kinect). A method is proposed to optimize the calibration of the depth cameras, to describe the multi-camera data fusion and to specify a global positioning projection to maintain the compatibility with outdoor positioning systems. The monitoring of the people trajectories at home is intended for the early detection of a shift in daily activities which highlights disabilities and loss of autonomy. This system is meant to improve homecare health management at home for a better end of life at a sustainable cost for the community

A Data Fusion System to Study Synchronization in Social Activities

As the world population gets older, the healthcare system must be adapted, among others by providing continuous health monitoring at home and in the city. The social activities have a significant role in everyone health status. Hence, this paper proposes a system to perform a data fusion of signals sampled on several subjects during social activities. This study implies the time synchronization of data coming from several sensors whether these are embedded on people or integrated in the environment. The data fusion is applied to several experiments including physical, cognitive and rest activities, with social aspects. The simultaneous and continuous analysis of four subjects cardiac activity and GPS coordinates provides a new way to distinguish different collaborative activities comparing the measurements between the subjects and along time.Comment: Healthcom 201

Poissons récoltés par dragages dans le lagon de Nouvelle-Calédonie

Au cours de l'échantillonnage à la drague des lagons de Nouvelle-Calédonie, 73 familles de poissons ont été récoltées; 4 d'entre elles sont signalées pour la première fois de la région. 323 espèces ont été recensées dont 49 pour la première fois de Nouvelle-Calédonie. Les familles et les espèces sont présentées avec leur pourcentage d'occurence dans les dragages. Des remarques biogéographiques sont faites par rapport aux régions environnantes et malgré de nombreuses lacunes dans les connaissances entre les faunes de Nouvelle-Calédonie et de la Grande Barrière Australienne. (Résumé d'auteur

Approche hydrochimique de la dégradation mécanique du versant instable de Séchilienne

National audienceLa chimie des eaux est un signal très fin qui permet la localisation dans le temps et dans l'espace de l'arrivée des eaux d'infiltration à l'origine des impulsions mécaniques des instabilités de versant. Il s'agit de comprendre comment s'organise la relation complexe entre altération chimique, modifications hydromécaniques et fragilisation/mouvements du versant rocheux instable. Pour cela, un suivi hydrogéochimique des eaux souterraines a été mis en place depuis 2010 sur le site de Séchilienne (France). La conductivité électrique est représentative du signal chimique engendré par la dégradation du massif. L'acquisition en continu de ce paramètre est pertinente pour le site de Séchilienne et peut se substituer au suivi chimique. L'avantage de l'acquisition de cette donnée est triple, ce qui peut en faire un outil pour la gestion du risque : mesure en temps réel, avec un pas de temps très fin et mise en œuvre peu coûteuse

Notch signalling is linked to epidermal cell differentiation level in basal cell carcinoma, psoriasis and wound healing

BACKGROUND: Epidermal homeostasis involves the monitoring of continuous proliferative and differentiative processes as keratinocytes migrate from the basal layer to the skin surface. Recently, differentiation of epidermal stem cells was shown to be promoted by the Notch pathway. This pathway is characterised by cell-cell interactions between transmembrane proteins and was first implicated in lateral inhibition, patterning and cell binary choices during embryogenesis. METHODS: By in situ hybridisation, we investigated the in vivo expression of related genes, namely; Notch 1–3, Delta 1, Jagged 1, Lunatic Fringe, Radical Fringe and Manic Fringe during keratinocyte proliferation and differentiation in humans in basal cell carcinoma, psoriasis and in wound healing experiments, compared with normal adult skin. RESULTS: We show that the highest level of transcription of these genes is in the basal cell layer of non-lesional skin. Conversely, when keratinocytes were hyperproliferating, as in basal cell carcinoma, psoriasis, and during the first step of re-epithelialisation, expression was weak or non-existent. Furthermore, normal levels of transcripts were rescued in psoriatic plaques when treated by phototherapy, as well as in newly regenerated stratified epidermis following wound healing. CONCLUSION: The Notch signalling involved in the differentiation programme of normal adult human epidermis is altered under experimental conditions and pathologies which modify this programme

Velocity model determination by the SMART method, Part 2: Application SP3.8

International audienceThe SMART (Sequential Migration Aided Reflection Tomography) method, as explained in the first part of this paper, starts after a first set of traveltimes in the unmigrated prestack data has been picked and the inventarization of useful a priori knowledge related to these traveltimes has been made. Thereto a preparative phase is needed. First a global estimate of the subsurface structure is made. Hereto we use the standard stacking and poststack interpretation procedures which 'allow for getting insight in the degree of complexity of the subsurface. Next the traveltimes can be picked. When interpreting prestack data important qualitative structural information in difficult target zones (e-g. fault zones or salt structure flanks) can be obtained. Such an analysis guides the interpreter in selecting and picking the best traveltimes of primary events. Once the preparation is finished the SMART method can be applied for a detailed determination of a structural and velocity model in a very consistent way. It is emphasized that velocity variations in complex structures can be determined accurately by prestack traveltime inversion techniques. This phase has an iterative character. In order to update the velocity model after the first iteration additional traveltimes are needed. Next additional traveltimes are obtained by interpretation of the cube of migrated data which can be easier than in the time domain due to the focussing and positioning effect of the migration process. By tracing rays in the same velocity model as was used for mi.gration on the newly interpreted events, we will obtain additional traveltimes which will make the set of input data for the next iteration of tomography more complete. A new velocity model is calculated and the data are remigrated. In this paper we will demonstrate the feasibility of this approach using a 2D real data set. We executed a number of iterations of the SMART method and ended up with of the complex structure. a very satisfactory depth image THE DATA We used for this application a 2D dataset covering a salt structure. It consists of 300 shotrecords at a regular interval of 40m. The acquisition was done in a split spread. The half spread length is 1920 meters with 48 geophones. The data were delivered with a standard preprocessing (filtering, zero-phase deconvolution and muting). Because of some clearly visible groundroll, we applied a second filter in order to remove most of this in Figure 1. low frequency noise. A partial stack of the data is shown THE PREPARATIVE PHASE Analysis of complexity In order to get an idea of the degree of complexity of a subsurface, it is useful to construct several partial stacks with the same stacking velocity model. Because the stacking process is based on flattening of the hyperbola's in CMP's, through some NMO and DMO based correction, differences in between the partial stacks demonstrate the failure of the process. In areas with complex subsurface structures these hyperbola's aren't necessarily flat due to different raypaths left and right of the midpoint. In this dataset this phenomenon can be observed in a series of CMP's covering the saltdome (See Figure 2). Another way to get an idea of the complexity is to do a post stack depth migration by a layer stripping approach using the best partial stack. For these data the results are satisfactory for the sedimentary zones left and right of the dome, but are incorrect for the deep interfaces and the base of the salt. This is partially due to events that are lost during the stacking procedure. Other causes for this failure are: the uncertainty in picking the right interface that serves as the next velocity boundary and the difficult choice of the velocities which becomes more and more hazardous as the depth increases. The final result is unreliable and the resulting depth for the base of the salt depends largely on the choices made by the interpreter Clearly these data cannot be handled by standard processing techniques. Left and right of the salt dome and below it the nature of the trace gathers is too complex. A prestack imaging method using a velocity model computed by tomography seems adequate for solving the aforementioned problems. Data preparation for the SMART method The next step after the analysis of the complexity is the data preparation for the SMART method. Its goal is to prepare an initial set of traveltimes to be used in the first iteration. We split this phase in a number of consecutive sub-phases: • Creating a initial set of guides for the prestack interpretation. • Picking traveltimes. • Quality control of the traveltimes. • Selection of representative traveltimes and calculation of the associated weights. Creating a set of guides. Guides are indicators for the interpreter suggesting where to look in the prestack unmigrated data for a certain event. They are also warnings for complicated situations as multiples, triplications and situations were no reliable indications for the nature of an event is available. The geologic guides are qualitative (e.g. presence of a fault) or quantitative (e.g. the depth of horizon A is 2500m). The geophysical guides are for example the presence of multiples or diffractions. They are derived from the unstacked or stacked data. For this dataset the following data were used: a set of (partial) stacks, time-and depth-migrated stacks and the cube of preprocessed prestack data. It allowed us to determine the zones where picking traveltimes directly in the unmigrated data could lead to incorrect traveltime information for the tomography. These zones are indicated in Figure 1 (Za and Zb, a zone with triplications and a series of unexplained events. Picking the first set of traveltimes Using the guides the picking of the traveltimes can start. This is done in the cube of unmigrated data. There is no preference for picking in a specific trace gather. This depends of the available guide. When it is a geological one the common offset gathers are most suited. Using a geophysical one the interpretation is done in the shotgathers or the common midpoint gathers. Whatever direction is chosen, one has to end 142