800 resultados para Physical Environment


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Programa de doctorado: Ecología y Gestión de los Recursos Vivos Marinos

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The study of the impact of climate change on the environment has been based, until very recently, on an global approach, whose interest from a local point of view is very limited. This thesis, on the contrary, has treated the study of the impact of climate change in the Adriatic Sea basin following a twofold strategy of regionalization and integration of numerical models in order to reproduce the present and future scenarios of the system through a more and more realistic and solid approach. In particular the focus of the study was on the impact on the physical environment and on the sediment transport in the basin. This latter is a very new and original issue, to our knowledge still uninvestigated. The study case of the coastal area of Montenegro was particularly studied, since it is characterized by an important supply of sediment through the Buna/Bojana river, second most important in the Adriatic basin in terms of flow. To do this, a methodology to introduce the tidal processes in a baroclinic primitive equations Ocean General Circulation Model was applied and tidal processes were successfully reproduced in the Adriatic Sea, analyzing also the impacts they have on the mean general circulation, on salt and heat transport and on mixing and stratification of the water column in the different seasons of the year. The new hydrodynamical model has been further coupled with a wave model and with a river and sea sediment transport model, showing good results in the reproduction of sediment transport processes. Finally this complex coupled platform was integrated in the period 2001-2030 under the A1B scenario of IPCC, and the impact of climate change on the physical system and on sediment transport was preliminarily evaluated.

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In future, the so called “sensing enterprise”, as part of the Future Internet, will play a crucial role in the success or the failure of an enterprise. We present our vision of an enterprise interacting with the physical world based on a retail scenario. One of the main challenges is the interoperability not only between the enterprise IT systems themselves, but also between these systems and the sensing devices. We will argue that semantically enriched service descriptions, the so called linked services will ease interoperability between two or more enterprises IT systems, and between enterprise systems and the physical environment.

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BACKGROUND: Our objective was to analyze subjective explanations for unsuccessful weight loss among bariatric surgery candidates. METHODS: This was a retrospective analysis of 909 bariatric surgery candidates (78.2% female, average body mass index [BMI] 47.3) at a university center from 2001 to April 2007 who answered an open-ended question about why they were unable to lose weight. We generated a coding scheme for answers to the question and established inter-rater reliability of the coding process. Associations with demographic parameters and initial BMI were tested. RESULTS: The most common categories of answers were nonspecific explanations related to diet (25.3%), physical activity (21.0%), or motivation (19.7%), followed by diet-related motivation (12.7%) and medical conditions or medications affecting physical activity (12.7%). Categories related to time, financial cost, social support, physical environment, and knowledge occurred in less than 4% each. Men were more likely than women to cite a medical condition or medication affecting physical activity (19.2% vs 10.8%, P = 0.002, odds ratio [OR] = 1.96, 95% confidence interval [CI] = 1.28-2.99) but less likely to cite diet-related motivation (7.1% vs 14.2%, P = 0.008, OR = 0.46, 95% CI = 0.26-0.82). CONCLUSIONS: Our findings suggest that addressing diet, physical activity, and motivation in a comprehensive approach would meet the stated needs of obese patients. Raising patient awareness of under-recognized barriers to weight loss, such as the physical environment and lack of social support, should also be considered. Lastly, anticipating gender-specific attributions may facilitate tailoring of interventions.

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Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of quenching-corrected fluorescence quantum yields reveal a striking consistency with anticipated patterns of iron availability. High fluorescence quantum yields are typically found in low iron waters, while low quantum yields dominate regions where other environmental factors are most limiting to phytoplankton growth. Specific properties of photosynthetic membranes are discussed that provide a mechanistic view linking iron stress to satellite-detected fluorescence. Our results present satellite-based fluorescence as a valuable tool for evaluating nutrient stress predictions in ocean ecosystem models and give the first synoptic observational evidence that iron plays an important role in seasonal phytoplankton dynamics of the Indian Ocean. Satellite fluorescence may also provide a path for monitoring climate-phytoplankton physiology interactions and improving descriptions of phytoplankton light use efficiencies in ocean productivity models.

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A study was conducted on the highlands of Ethiopia to identify and analyse the factors determining the adoption of environmental management measures. In 1985, Ethiopia was classified into low –and high-potential areas based on the suitability of the natural environment for rain-fed agriculture. To address these objectives, case study areas were selected from low-potential and high-potential areas randomly. Data were collected through face-to-face interview and key informants, focus group discussion and field observation. In the low-potential areas, the physical environment ‒ particularly soil and forest environments have shown substantial recovery. Similarly, the water environment has improved. However, in the high-potential areas sampled, these resources are still being degraded. Clear understanding of the benefits of soil conservation structures by farmers, active involvement and technical support from the government and full and genuine participation of farmers in communal environmental resources management activities were found to be main factors in the adoption of environmental management measures.

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Dietary intake is a complex, health-related behavior, and although individual-level theoretical models explain some variation in dietary intake, comprehensive theoretical models such as the ecological framework describe the multiple levels which influence diet-related behaviors. Thus, the ecological framework is a preferred model for designing comprehensive nutrition interventions. While ecological-based nutrition interventions have been described, little work has focused on interventions in the hospital setting. Because hospitals are considered the hallmarks of health, it might seem that hospitals would regularly engage in worksite nutrition promotion; however, recent publications and other anecdotal evidence have indicated otherwise. The first paper of this dissertation systematically reviewed the scientific literature between 1996 and 2012 and identified 13 outcome evaluation trials for hospital-based worksite nutrition interventions. Of these 13 interventions, only one intervention targeted three of the four levels of the ecological framework and no intervention targeted all four levels. Only half of the interventions targeted the physical environment of hospitals, thus warranting more investigation into this specific level of the ecological framework in this setting. ^ A critical type of nutrition-related physical environments is the consumer nutrition environment. Although other tools measure the consumer nutrition environments of stores and restaurants, no tool specifically measured the consumer nutrition environments of hospitals until the CDC developed the Healthy Hospital Environment Scan for Cafeterias, Vending Machines, and Gift Shops (HHES-CVG). The HHES-CVG, a tool which measures the consumer nutrition environments of hospital cafeterias, vending machines, and gifts shops, was released in November 2011, and in the second paper of this dissertation, the reliability of this tool was investigated. Two trained raters visited 39 hospitals across Southern California between February and May 2012, and based on analyses of the raters' findings, the HHES-CVG exhibited strong reliability metrics (inter-observer agreement between 74 and 100%, and an intraclass correlation coefficient of 0.961 for the overall nutrition composite score). Because the HHES-CVG was found to be a reliable tool, the third paper of this dissertation presented HHES-CVG results from the 39 hospitals. Overall, hospitals only scored about one-fourth of the total possible points for the nutrition composite score, indicating that most facilities do not have acceptable consumer nutrition environments. Some of the best practices observed in cafeterias were significantly associated with having a large facility and with having a contracted foodservice operation, but overall nutrition composite score was not associated with any specific facility or operation type. ^ The dissertation concluded that much work is needed in order to improve the consumer nutrition environments of hospitals. Practitioners and healthcare administrators should consider starting with ecological-based interventions addressing all levels including the physical environment.^

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Fifteen lengths of Leg 59 cores (primarily from Hole 451 as well as from Holes 447A and 448A) exhibiting macroscopic faults were selected by Dr. R. B. Scott (Co-Chief Scientist, Leg 59) to help us initiate this petrofabric analysis. We proposed to (1) determine what dynamically useful deformation features might be associated with the faults, and (2) infer from these features as much as possible about the physical environment of the deformation (effective pressure, differential stress, temperature, and strain rate), the orientation and relatively magnitudes of the principal stresses at the time of deformation, and the degree of induration of the rocks at the time of deformation. The cores, mainly from Hole 451, had been slabbed on board ship with respect to the trace of bedding so that each cut surface contains the true bedding dip-direction. In general, the cores from Hole 451 are largely calcareous, lithic and vitric, brecciated tuffs, whereas those from Holes 447A and 448A are basalts or basalt breccias.

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Cores from four Ocean Drilling Program (ODP) sites were examined for planktonic foraminifers. One sample per core (from core-catchers in Holes 806B and 807B and from Section 4 in Holes 847B and 852B) was examined through the interval representing the last 5.8 m.y. Sites 806 (0°19.1'N; 159°21.7'E) and 847 (0o12.1'N; 95°19.2'W) are beneath the equatorial divergence zone. Sites 807 (3°36.4'N; 156°37.5'E) and 852 (5°19.6'N; 110°4.6'W) are located north of the equator in the convergence zone created by the interaction of the westward-flowing South Equatorial Current (SEC) and the eastward-flowing North Equatorial Countercurrent (NECC). Specimens were identified to species and then grouped according to depth habitat and trophic level. Species richness and diversity were also calculated. Tropical neogloboquadrinids have been more abundant in the eastern than in the western equatorial Pacific Ocean throughout the last 5.8 m.y. During the mid-Pliocene (3.8-3.2 Ma), their abundance increased at all sites, while during the Pleistocene (after ~ 1.6 Ma), they expanded in the east and declined in the west. This suggests an increase in surface-water productivity across the Pacific Ocean during the closing of the Central American seaway and an exacerbation of the productivity asymmetry between the eastern and western equatorial regions during the Pleistocene. This faunal evidence agrees with eolian grain-size data (Hovan, 1995) and diatom flux data (Iwai, this volume), which suggest increases in tradewind strength in the eastern equatorial Pacific that centered around 3.5 and 0.5 Ma. The present longitudinal zonation of thermocline dwelling species, a response to the piling of warm surface water in the western equatorial region of the Pacific, seems to have developed after 2.4 Ma, not directly after the closing of the Panama seaway (3.2 Ma). Apparently, after 2.4 Ma, the piling warm water in the west overwhelmed the upwelling of nutrients into the photic zone in that region, creating the Oceanographic asymmetry that exists in the modern tropical Pacific and is reflected in the microfossil record. In the upper Miocene and lower Pliocene sediments, the ratio of thermocline-dwelling species to mixed-layer dwellers is 60%:40%. During the mid-Pliocene, the western sites became 40% thermocline and 60% mixed-layer dwellers. Subsequent to -2.4 Ma, the asymmetry increased to 20%: 80% in the west and the reverse in the east. This documents the gradual thickening of the warm-water layer piled up in the western tropical Pacific over the last 5.8 m.y. and reveals two "steps" in the biotic trend that can be associated with specific events in the physical environment.

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In order to gain insights into species-level behavioural responses to the physical environment, it is necessary to obtain information from various populations and at all times of year. We analysed the influences of physical environmental parameters on the mid-summer dive behaviour of Weddell seals (Leptonychotes weddellii) from a little-known population at Atka Bay, Antarctica. Dive depth distributions followed a typical bimodal pattern also exhibited by seals from other populations and seals targeted both shallow water layers of <50 m and depths near the seafloor. Increased stratification of temperature layers within the water column resulted in increased forage efforts by the seals through relatively high numbers of dives to the seafloor, as well as forage effort associated with shallow dives. We interpret these behavioural responses to be due to increased water temperature stratification resulting in the concentration of prey species in particular depth layers.

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The spatial variation in mesozooplankton biomass, abundance and species composition in relation to oceanography was studied in different climatic regimes (warm Atlantic vs. cold Arctic) in northern Svalbard waters. Relationships between the zooplankton community and various environmental factors (salinity, temperature, sampling depth, bottom depth, sea-ice concentrations, algal biomass and bloom stage) were established using multivariate statistics. Our study demonstrated that variability in the physical environment around Svalbard had measurable effect on the pelagic ecosystem. Differences in bottom depth and temperature-salinity best explained more than 40% of the horizontal variability in mesozooplankton biomass (DM/m**2) after adjusting for seasonal variability. Salinity and temperature also explained much (21% and 15%, respectively) of the variability in mesozooplankton vertical distribution (ind./m**3) in August. Algal bloom stage, chlorophyll-a biomass, and depth stratum accounted for additional 17% of the overall variability structuring vertical zooplankton distribution. Three main zooplankton communities were identified, including Atlantic species Fritillaria borealis, Oithona atlantica, Calanus finmarchicus, Themisto abyssorum and Aglantha digitale; Arctic species Calanus glacialis, Gammarus wilkitzkii, Mertensia ovum and Sagitta elegans; and deeper-water inhabitants Paraeuchaeta spp., Spinocalanus spp., Aetideopsis minor, Mormonilla minor, Scolecithricella minor, Gaetanus (Gaidius) tenuispinus, Ostracoda, Scaphocalanus brevicornis and Triconia borealis. Zooplankton biomasses in Atlantic- and Arctic-dominated water masses were similar, but biological ''hot-spots'' were associated with Arctic communities.

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Reproduction in many organisms can be disrupted by changes to the physical environment, such as those predicted to occur during climate change. Marine organisms face the dual climate change threats of increasing temperature and ocean acidification, yet no studies have examined the potential interactive effects of these stressors on reproduction in marine fishes. We used a long-term experiment to test the interactive effects of increased temperature and CO2 on the reproductive performance of the anemonefish, Amphiprion melanopus. Adult breeding pairs were kept for 10 months at three temperatures, 28.5°C (+0.0°C), 30.0°C (+1.5°C) and 31.5°C (+3.0°C), cross-factored with 3 CO2 levels, a current day control (417 µatm) and moderate (644 µatm) and high (1134 µatm) treatments consistent with the range of CO2 projections for the year 2100 under RCP8.5. We recorded each egg clutch produced during the breeding season, the number of eggs laid per clutch, average egg size, fertilization success, survival to hatching, hatchling length and yolk provisioning. Adult body condition, hepatosomatic index, gonadosomatic index, and plasma 17beta-estradiol concentrations were measured at the end of the breeding season to determine the effect of prolonged exposure to increased temperature and elevated CO2 on adults, and to examine potential physiological mechanisms for changes in reproduction. Temperature had by far the stronger influence on reproduction, with clear declines in reproduction occurring in the +1.5°C treatment and ceasing altogether in the +3.0°C treatment. In contrast, CO2 had a minimal effect on the majority of reproductive traits measured, but caused a decline in offspring quality in combination with elevated temperature. We detected no significant effect of temperature or CO2 on adult body condition or hepatosomatic index. Elevated temperature had a significant negative effect on plasma 17beta-estradiol concentrations, suggesting that declines in reproduction with increasing temperature were due to the thermal sensitivity of reproductive hormones rather than a reduction in energy available for reproduction. Our results show that elevated temperature exerts a stronger influence than high CO2 on reproduction in A. melanopus. Understanding how these two environmental variables interact to affect the reproductive performance of marine organisms will be important for predicting the future impacts of climate change.

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La presente investigación parte del problema en las zonas de clima cálido - húmedo en las cuales se producen impactos asociados a la incomodidad térmica producto de la intensa radiación solar, altas temperaturas y elevada humedad. Estos factores reducen la calidad de los espacios abiertos y desarrollan en la población una actitud de rechazo hacia el uso del microespacio urbano entre edificaciones en los desarrollos urbanos - conjuntos urbanos - , los mismos frecuentemente admiten soluciones que al parecer no contribuyen a la realización de las actividades comunes de esparcimiento de la población residente. Por lo tanto, el objetivo de la investigación es profundizar en la temática urbano - ambiental - social y el diseño urbano vinculada a la particularidad morfológica local, las condiciones microclimáticas, el uso del microespacio y los requerimientos de los usuarios. La finalidad de desarrollar estrategias de control microclimático del microespacio entre edificios en clima cálido - húmedo en búsqueda de soluciones óptimas que satisfagan las necesidades de los usuarios de los espacios exteriores en estas áreas residenciales. La investigación se centra en el estudio de las particularidades contextuales relacionadas con el microclima y las características urbanas - morfotipológicas, básicamente los factores microclimáticos (soleamiento y ventilación), los morfológicos y edificatorios y las características de las superficies (pavimentos). En coherencia con el objetivo propuesto el trabajo se desarrolla en cuatro fases: la primera aborda la revisión documental, literatura relevante e investigaciones relativas a la calidad ambiental, medio social, medio físico, el microespacio urbano, control y diseño sostenible, modelización proyectual y estrategias sostenibles; la segunda fase se refiere al marco contextual, características urbanas, datos climáticos locales, planes y procesos urbanos, tipologías y conformación urbana. En esta fase se describe el proceso de selección, análisis y evaluación urbano - ambiental de los casos de estudio (conjuntos residenciales). En la tercera fase se aborda el marco evaluativo y estudio de casos, consideraciones físicas, climáticas y valoración térmico - ambiental de los conjuntos residenciales seleccionados. En esta fase se aplican Técnicas Estadísticas y de Simulación Computacional y se analizan los resultados obtenidos. Finalmente, la cuarta fase propositiva incluye el establecimiento de Estrategias, Principios y Lineamientos de optimación térmica y se exponen las Conclusiones parciales de la tesis, alcances y perspectivas futuras. Finalmente, los resultados obtenidos en la investigación demuestran que el análisis en las experiencias de la realidad permiten comprobar que las situaciones y alteraciones ambientales sustanciales, los niveles de afectación térmica y las condiciones de confortabilidad e impacto derivan de las características urbanas, los componentes del microespacio y de las condiciones climáticas las cuales afectan el desarrollo de las actividades y el uso efectivo del microespacio entre edificios. El análisis de los factores morfo - climáticos incidentes y el estudio de los efectos de interacción contribuyen al establecimiento de Principios y Lineamientos para la evaluación y diseño sostenible del microespacio entre edificios y el uso correcto de los elementos del clima en estas áreas urbanas destinadas a la actividad social y al esparcimiento de la población residente. ABSTRACT This research starts from the problem of hot - humid climate zones where impacts related to thermal discomfort are produced as a result from the intense solar radiation and high temperatures and humidity. These factors reduce the quality of open spaces and people develop an attitude of rejection towards the use of urban microspace among buildings within urban developments - urban complexes - . Usually, these complexes admit solutions that apparently do not contribute to the achievement of common leisure activities in the resident dwellers. Therefore, the main purpose of this research is to deepen in the urban - environmental - social issue and urban design linked to the local morphological particularity, microclimate conditions, use of microspace and users’ requirements. In order to develop microclimate control strategies of microspace among buildings in hot - humid climate to look for optimal solutions that satisfy users’ needs of outdoors spaces in these residential areas. The research focuses in the study of contextual particularities related to microclimate and urban - morphotypological characteristics. Basically, microclimate (sunlight and ventilation), morphological and building factors as well as road surface characteristics. According to the proposed objective, this research is developed in four phases: the first one considers documentary review, relevant literature and researches related to environmental quality, social environment, physical environment, urban microspace, control and sustainable design, project modelling and sustainable strategies; while the second phase refers to contextual framework, urban characteristics, local climate data, plans and urban processes, typologies and urban structure. In this phase, the process of selection, analysis and urban - environmental evaluation of case studies (residential complexes) is described. The third phase approaches the assessment framework and case studies, physical and climate considerations as well as environmental - thermal evaluation of selected residential complexes. In this phase, statistical techniques and computational simulations are applied. Likewise, results obtained are analysed. Similarly, fourth and proposing phase includes the establishment of strategies, principles and guidelines of thermal optimization and partial conclusions of the thesis, scopes and future perspectives are exposed. Finally, from the results obtained, it is demonstrated that the analysis on reality experiences allow proving that situations and substantial environmental changes, levels of thermal affectations, comfort conditions and impact derive from urban characteristics, microspace components and from climate conditions which affect the development of activities and the effective use of microspace among buildings. The analysis of incidental morpho - climate factors and the study of interaction effects contribute to the establishment of principles and guidelines for the assessment and sustainable design of microspace among buildings as well as the correct use of climate elements in these urban areas oriented to social and leisure activities of resident population.

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Spain pioneered policies related to disability and accessibility, especially in the physical environment. The first major piece of legislation was Act 13/1982 on the Social Integration of People with Disabilities. The law was published just a few years after the reinstitution of democracy in Spain in 1977 and the approval of the Spanish Constitution in 1978. Act 13/1982 is a general law that applies accessibility to social services and education, as well as to workplace and physical accessibility. This law targeted first and foremost the social integration of people with disabilities, and it was a significant success, especially in the field of employment, as it made it mandatory for private companies and public administrations to employ a certain percentage of persons with disabilities. This greatly increased the employability of people with disabilities, as highlighted in a document celebrating 30 years of Act 13/1982. Over the past 20 years, policy makers have also focused on accessibility to information and communication technologies (ICT), developing first the national computing accessibility standards and then specialized legislation. Initially, Spanish activities were mostly national but have now gained an international dimension. All these initiatives are strongly related to the discipline of human-computer interaction, as the key component of an accessible system is its user interface.

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The well-documented re-colonisation of the French large river basins of Loire and Rhone by European otter and beaver allowed the analysis of explanatory factors and threats to species movement in the river corridor. To what extent anthropogenic disturbance of the riparian zone influences the corridor functioning is a central question in the understanding of ecological networks and the definition of restoration goals for river networks. The generalist or specialist nature of target species might be determining for the responses to habitat quality and barriers in the riparian corridor. Detailed datasets of land use, human stressors and hydro-morphological characteristics of river segments for the entire river basins allowed identifying the habitat requirements of the two species for the riparian zone. The identified critical factors were entered in a network analysis based on the ecological niche factor approach. Significant responses to riparian corridor quality for forest cover, alterations of channel straightening and urbanisation and infrastructure in the riparian zone are observed for both species, so they may well serve as indicators for corridor functioning. The hypothesis for generalists being less sensitive to human disturbance was withdrawn, since the otter as generalist species responded strongest to hydro-morphological alterations and human presence in general. The beaver responded the strongest to the physical environment as expected for this specialist species. The difference in responses for generalist and specialist species is clearly present and the two species have a strong complementary indicator value. The interpretation of the network analysis outcomes stresses the need for an estimation of ecological requirements of more species in the evaluation of riparian corridor functioning and in conservation planning.