991 resultados para Missions.


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Potential Desiccation Polygons (PDPs), tens to hundreds of meters in size, have been observed in numerous regions on Mars, particularly in ancient (>3Gyr old) terrains of inferred paleolacustrine/playa geologic setting, and in association with hydrous minerals such as smectites. Therefore, a better understanding of the conditions in which large desiccation polygons form could yield unique insight into the ancient climate on Mars. Many dried lakebeds/playas in western United States display large (>50m wide) desiccation polygons, which we consider to be analogues for PDPs on Mars. Therefore, we have carried out fieldwork in seven of these dried lakes in San Bernardino and the Death Valley National Park regions complemented with laboratory and spectral analysis of collected samples. Our study shows that the investigated lacustrine/playa sediments have (a) a soil matrix containing 40-75% clays and fine silt (by volume) where the clay minerals are dominated by illite/muscovite followed by smectite, (b) carbonaceous mineralogy with variable amounts of chloride and sulfate salts, and significantly, (c) roughly similar spectral signatures in the visible-near-infrared (VIS-NIR) range. We conclude that the development of large desiccation fractures is consistent with water table retreat. In addition, the comparison of the mineralogical to the spectral observations further suggests that remote sensing VIS-NIR spectroscopy has its limitations for detailed characterization of lacustrine/playa deposits. Finally, our results imply that the widespread distribution of PDPs on Mars indicates global or regional climatic transitions from wet conditions to more arid ones making them important candidate sites for future in situ missions.

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Astronauts performing extravehicular activities (EVA) are at risk for occupational hazards due to a hypobaric environment, in particular Decompression Sickness (DCS). DCS results from nitrogen gas bubble formation in body tissues and venous blood. Denitrogenation achieved through lengthy staged decompression protocols has been the mainstay of prevention of DCS in space. Due to the greater number and duration of EVAs scheduled for construction and maintenance of the International Space Station, more efficient alternatives to accomplish missions without compromising astronaut safety are desirable. ^ This multi-center, multi-phase study (NASA-Prebreathe Reduction Protocol study, or PRP) was designed to identify a shorter denitrogenation protocol that can be implemented before an EVA, based on the combination of adynamia and exercise enhanced oxygen prebreathe. Human volunteers recruited at three sites (Texas, North Carolina and Canada) underwent three different combinations (“PRP phases”) of intense and light exercise prior to decompression in an altitude chamber. The outcome variables were detection of venous gas embolism (VGE) by precordial Doppler ultrasound, and clinical manifestations of DCS. Independent variables included age, gender, body mass index, oxygen consumption peak, peak heart rate, and PRP phase. Data analysis was performed both by pooling results from all study sites, and by examining each site separately. ^ Ten percent of the subjects developed DCS and 20% showed evidence of high grade VGE. No cases of DCS occurred in one particular PRP phase with use of the combination of dual-cycle ergometry (10 minutes at 75% of VO2 peak) plus 24 minutes of light EVA exercise (p = 0.04). No significant effects were found for the remaining independent variables on the occurrence of DCS. High grade VGE showed a strong correlation with subsequent development of DCS (sensitivity, 88.2%; specificity, 87.2%). In the presence of high grade VGE, the relative risk for DCS ranged from 7.52 to 35.0. ^ In summary, a good safety level can be achieved with exercise-enhanced oxygen denitrogenation that can be generalized to the astronaut population. Exercise is beneficial in preventing DCS if a specific schedule is followed, with an individualized VO2 prescription that provides a safety level that can then be applied to space operations. Furthermore, VGE Doppler detection is a useful clinical tool for prediction of altitude DCS. Because of the small number of high grade VGE episodes, the identification of a high probability DCS situation based on the presence of high grade VGE seems justified in astronauts. ^

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This talk consists of two parts - first part deals with what Jeffrey Bolster called “The Changing Nature of Maritime Insurrection”- and I will tie that into some research that I did on a New York clipper ship called the Contest. The second part of the talk will look at the rise of seafarer’s missions and that will tie Roald Kverndal’s magnum opus Seamen’s Missions: Their Origin and Early Growth into some research that I did on the earliest work done in New York among seafarers that pre-dated the American Seamen’s Friend Society.

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Colleges and universities’ missions are typically comprised of educating students, training professionals, engaging in scholarship and research, promoting creative activity, improving healthcare, and providing public service. Academic libraries exist to support these core functions, yet most academic libraries are organized based on library functions rather than the primary missions of their college or university. This paper describes one academic library’s attempt to align library strategy and structure with its university’s academic plan.

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The State of Connecticut owns a LIght Detection and Ranging (LIDAR) data set that was collected in 2000 as part of the State’s periodic aerial reconnaissance missions. Although collected eight years ago, these data are just now becoming ready to be made available to the public. These data constitute a massive “point cloud”, being a long list of east-north-up triplets in the State Plane Coordinate System Zone 0600 (SPCS83 0600), orthometric heights (NAVD 88) in US Survey feet. Unfortunately, point clouds have no structure or organization, and consequently they are not as useful as Triangulated Irregular Networks (TINs), digital elevation models (DEMs), contour maps, slope and aspect layers, curvature layers, among others. The goal of this project was to provide the computational infrastructure to create a first cut of these products and to serve them to the public via the World Wide Web. The products are available at http://clear.uconn.edu/data/ct_lidar/index.htm.

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von Weßmann

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par Moïse Schwab

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Major objectives within Healthy People 2010 include improving hypertension and mental health management of the American population. Both mental health issues and hypertension exist in the military which may decrease the health status of military personnel and diminish the ability to complete assigned missions. Some cases may be incompatible with military service even with optimum treatment. In the interest of maintaining a fit fighting force, the Department of Defense regularly conducts a survey of health related behaviors among active duty military personnel. The 2005 DoD Survey was conducted to obtain information regarding health and behavioral readiness among active duty military personnel to assess progress toward selected Healthy People 2010 objectives. ^ This study is a cross-sectional prevalence design looking at the association of hypertension treatment with mental health issues (either treatment or perceived need for treatment) within the military population sampled in the 2005 DoD Survey. There were 16,946 military personnel in the final cross-sectional sample representing 1.3 million active duty service members. The question is whether there is a significant association between the self-reported occurrence of hypertension and the self-reported occurrence of mental health issues in the 2005 DoD Survey. In addition to these variables, this survey examined the contribution of various sociodemographic, occupational, and behavioral covariates. An analysis of the demographic composition of the study variables was followed by logistic analysis, comparing outcome variables with each of the independent variables. Following univariate regression analysis, multivariate regression was performed with adjustment (for those variables with an unadjusted alpha level less than or equal to 0.25). ^ All the mental health related indicators were associated with hypertension treatment. The same relationship was maintained after multivariate adjustment. The covariates remaining as significant (p < 0.05) in the final model included gender, age, race/ethnicity and obesity. There is a need to recognize and treat co-morbid medical diagnoses among mental health patients and to improve quality of life outcomes, whether in the military population or the general population. Optimum health of the individual can be facilitated through discovery of treatable cases, to minimize disruptions of military missions, and even allow for continued military service. ^

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The objectives of this study were to identify and measure the average outcomes of the Open Door Mission's nine-month community-based substance abuse treatment program, identify predictors of successful outcomes, and make recommendations to the Open Door Mission for improving its treatment program.^ The Mission's program is exclusive to adult men who have limited financial resources: most of which were homeless or dependent on parents or other family members for basic living needs. Many, but not all, of these men are either chemically dependent or have a history of substance abuse.^ This study tracked a cohort of the Mission's graduates throughout this one-year study and identified various indicators of success at short-term intervals, which may be predictive of longer-term outcomes. We tracked various levels of 12-step program involvement, as well as other social and spiritual activities, such as church affiliation and recovery support.^ Twenty-four of the 66 subjects, or 36% met the Mission's requirements for success. Specific to this success criteria; Fifty-four, or 82% reported affiliation with a home church; Twenty-six, or 39% reported full-time employment; Sixty-one, or 92% did not report or were not identified as having any post-treatment arrests or incarceration, and; Forty, or 61% reported continuous abstinence from both drugs and alcohol.^ Five research-based hypotheses were developed and tested. The primary analysis tool was the web-based non-parametric dependency modeling tool, B-Course, which revealed some strong associations with certain variables, and helped the researchers generate and test several data-driven hypotheses. Full-time employment is the greatest predictor of abstinence: 95% of those who reported full time employment also reported continuous post-treatment abstinence, while 50% of those working part-time were abstinent and 29% of those with no employment were abstinent. Working with a 12-step sponsor, attending aftercare, and service with others were identified as predictors of abstinence.^ This study demonstrates that associations with abstinence and the ODM success criteria are not simply based on one social or behavioral factor. Rather, these relationships are interdependent, and show that abstinence is achieved and maintained through a combination of several 12-step recovery activities. This study used a simple assessment methodology, which demonstrated strong associations across variables and outcomes, which have practical applicability to the Open Door Mission for improving its treatment program. By leveraging the predictive capability of the various success determination methodologies discussed and developed throughout this study, we can identify accurate outcomes with both validity and reliability. This assessment instrument can also be used as an intervention that, if operationalized to the Mission’s clients during the primary treatment program, may measurably improve the effectiveness and outcomes of the Open Door Mission.^

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On-orbit exposures can come from numerous factors related to the space environment as evidenced by almost 50 years of environmental samples collected for water analysis, air analysis, radiation analysis, and physiologic parameters. For astronauts and spaceflight participants the occupational exposures can be very different from those experienced by workers performing similar tasks in workplaces on Earth, because the duration of the exposure could be continuous for very long orbital, and eventually interplanetary, missions. The establishment of long-term exposure standards is vital to controlling the quality of the spacecraft environment over long periods. NASA often needs to update and revise its prior exposure standards (Spacecrafts Maximum Allowable Concentrations (SMACs)). Traditional standards-setting processes are often lengthy, so a more rapid method to review and establish standards would be a substantial advancement in this area. This project investigates use of the Delphi method for this purpose. ^ In order to achieve the objectives of this study a modified Delphi methodology was tested in three trials executed by doctoral students and a panel of experts in disciplines related to occupational safety and health. During each test/trial modifications were made to the methodology. Prior to submission of the Delphi Questionnaire to the panel of experts a pilot study/trial was conducted using five doctoral students with the goals of testing and adjusting the Delphi questionnaire to improve comprehension, work out any procedural issues and evaluate the effectiveness of the questionnaire in drawing the desired responses. The remainder of the study consisted of two trials of the Modified Delphi process using 6 chemicals that currently have the potential of causing occupational exposures to NASA astronauts or spaceflight participants. To assist in setting Occupational Exposure Limits (OEL), the expert panel was established consisting of experts from academia, government and industry. Evidence was collected and used to create close-ended questionnaires which were submitted to the Delphi panel of experts for the establishment of OEL values for three chemicals from the list of six originally selected (trial 1). Once the first Delphi trial was completed, adjustments were made to the Delphi questionnaires and the process above was repeated with the remaining 3 chemicals (trial 2). ^ Results indicate that experience in occupational safety and health and with OEL methodologies can have a positive effect in minimizing the time experts take in completing this process. Based on the results of the questionnaires and comparison of the results with the SMAC already established by NASA, we conclude that use of the Delphi methodology is appropriate for use in the decision-making process for the selection of OELs.^

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Time variable gravity fields, reflecting variations of mass distribution in the system Earth is one of the key parameters to understand the changing Earth. Mass variations are caused either by redistribution of mass in, on or above the Earth's surface or by geophysical processes in the Earth's interior. The first set of observations of monthly variations of the Earth gravity field was provided by the US/German GRACE satellite mission beginning in 2002. This mission is still providing valuable information to the science community. However, as GRACE has outlived its expected lifetime, the geoscience community is currently seeking successor missions in order to maintain the long time series of climate change that was begun by GRACE. Several studies on science requirements and technical feasibility have been conducted in the recent years. These studies required a realistic model of the time variable gravity field in order to perform simulation studies on sensitivity of satellites and their instrumentation. This was the primary reason for the European Space Agency (ESA) to initiate a study on ''Monitoring and Modelling individual Sources of Mass Distribution and Transport in the Earth System by Means of Satellites''. The goal of this interdisciplinary study was to create as realistic as possible simulated time variable gravity fields based on coupled geophysical models, which could be used in the simulation processes in a controlled environment. For this purpose global atmosphere, ocean, continental hydrology and ice models were used. The coupling was performed by using consistent forcing throughout the models and by including water flow between the different domains of the Earth system. In addition gravity field changes due to solid Earth processes like continuous glacial isostatic adjustment (GIA) and a sudden earthquake with co-seismic and post-seismic signals were modelled. All individual model results were combined and converted to gravity field spherical harmonic series, which is the quantity commonly used to describe the Earth's global gravity field. The result of this study is a twelve-year time-series of 6-hourly time variable gravity field spherical harmonics up to degree and order 180 corresponding to a global spatial resolution of 1 degree in latitude and longitude. In this paper, we outline the input data sets and the process of combining these data sets into a coherent model of temporal gravity field changes. The resulting time series was used in some follow-on studies and is available to anybody interested.

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En 1900 el gobierno argentino creó el Territorio de Los Andes, el último de los diez que existieron en el país, en terrenos ganados a Chile después de una década de disputas diplomáticas, como un corolario de la Guerra del Pacífico. El nuevo territorio se distribuía en su totalidad en zonas montañosas y hasta el momento de su incorporación existía en el país un casi total desconocimiento sobre sus particularidades. A través de las diferentes misiones oficiales y de investigaciones independientes, en la siguiente década y media se produjo conocimiento empírico que fue abonando a la idea de que el nuevo territorio tenía cifrado su destino en dos actividades extractivas: la minería del borato y el aprovechamiento de fibras de vicuñas y pieles de chinchillas. Pero el desarrollo de ambas actividades se enfrentaba a una serie de obstáculos, que tenían que ver con la falta de medios de transporte, la ausencia de capitales y la falta de mecanismos oficiales de estímulo, en el contexto del un país con un perfil productivo eminentemente agroexportador de vacunos y cereales. La falta de crecimiento económico y el escaso crecimiento demográfico, entre otras razones, llevaron a la disolución institucional y la fragmentación territorial de Los Andes en 1943.