967 resultados para arid and semiarid region
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The Tara Oceans Expedition (2009-2013) sampled the world oceans on board a 36 m long schooner, collecting environmental data and organisms from viruses to planktonic metazoans for later analyses using modern sequencing and state-of-the-art imaging technologies. Tara Oceans Data are particularly suited to study the genetic, morphological and functional diversity of plankton. The present data set provides environmental context to all samples from the Tara Oceans Expedition (2009-2013), about mesoscale features related to the sampling date, time and location. Includes calculated averages of mesaurements made concurrently at the sampling location and depth, and calculated averages from climatologies (AMODIS, VGPM) and satellite products.
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Water is a vital resource, but also a critical limiting factor for economic and social development in many parts of the world. The recent rapid growth in human population and water use for social and economic development is increasing the pressure on water resources and the environment, as well as leading to growing conflicts among competing water use sectors (agriculture, urban, tourism, industry) and regions (Gleick et al., 2009; World Bank, 2006). In Spain, as in many other arid and semi-arid regions affected by drought and wide climate variability, irrigated agriculture is responsible for most consumptive water use and plays an important role in sustaining rural livelihoods (Varela-Ortega, 2007). Historically, the evolution of irrigation has been based on publicly-funded irrigation development plans that promoted economic growth and improved the socio-economic conditions of rural farmers in agrarian Spain, but increased environmental damage and led to excessive and inefficient exploitation of water resources (Garrido and Llamas, 2010; Varela-Ortega et al., 2010). Currently, water policies in Spain focus on rehabilitating and improving the efficiency of irrigation systems, and are moving from technocratic towards integrated water management strategies driven by the European Union (EU) Water Framework Directive (WFD).
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La actividad minera tiene un gran impacto sobre el territorio, probablemente más que ninguna otra de las actividades humanas, ya que transforma el espacio en todas sus dimensiones: ecológica, ambiental, social y económica. Cuando la reducción de la rentabilidad de la explotación conduce al cierre de ésta, la repercusión sobre su entorno puede llegar a ser brutal. Pero las explotaciones mineras son muy distintas entre ellas y los efectos que su abandono producen sobre el espacio en la que se enclavan pueden ser diversos, por lo que la decisión sobre el futuro de estas áreas no es simple y evidente. Aquí se propone desarrollar una propuesta de clasificación tipológica de las minas y sus regiones con el objetivo de determinar las estrategias de intervención más adecuadas para el futuro de estos espacios y sus habitantes. En concreto se busca diferenciar los conceptos de Mina, Parque Minero, Espacio Minero y Región Minera, todos ellos fruto de la interacción de la huella de la actividad minera con el medio físico, los enclaves urbanizados, y la estructura socioeconómica de la región en la que se enclavan. Mining activity is having a great impact on the territory, probably more than any other human activity, which transforms the space in all of its dimensions, ecological, environmental, social and economic. When reducing the profitability of the operation leads to the conclusion thereof, the impact on the environment can be brutal. But mining are very different between them and the effects they produce on their abandonment in space that interlock can be diverse, so the decision on the future of these areas is not simple and obvious. This proposal aims to develop a typological classification of mines and their regions in order to determine the most appropriate intervention strategies for the future of these spaces and their inhabitants. Specifically, it seeks to differentiate the concepts of Mine, Mining Park, Space Miner and Mining Region, all the result of the interaction of the mining footprint with the physical environment, the urbanized enclaves, and the socio-economic structure of the region which interlock. El presente libro reúne las ponencias presentadas por los investigadores de la red REUSE dentro del 1er Simposio de Reutilización del Espacio Minero; evento organizado por la Universidad Federal de Minas Gerais (UFMG) en Belo Horizonte, entre el 1 y el 3 de octubre de 2012, en el marco del 1er Seminario Internacional de Reconversión de Territorios. La red REUSE es una red realizada gracias a la financiación del programa CYTED
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The biogeochemical cycles of carbon (C), nitrogen (N) and phosphorus (P) are interlinked by primary production, respiration and decomposition in terrestrial ecosystems. It has been suggested that the C, N and P cycles could become uncoupled under rapid climate change because of the different degrees of control exerted on the supply of these elements by biological and geochemical processes. Climatic controls on biogeochemical cycles are particularly relevant in arid, semi-arid and dry sub-humid ecosystems (drylands) because their biological activity is mainly driven by water availability. The increase in aridity predicted for the twenty-first century in many drylands worldwide may therefore threaten the balance between these cycles, differentially affecting the availability of essential nutrients. Here we evaluate how aridity affects the balance between C, N and P in soils collected from 224 dryland sites from all continents except Antarctica. We find a negative effect of aridity on the concentration of soil organic C and total N, but a positive effect on the concentration of inorganic P. Aridity is negatively related to plant cover, which may favour the dominance of physical processes such as rock weathering, a major source of P to ecosystems, over biological processes that provide more C and N, such as litter decomposition. Our findings suggest that any predicted increase in aridity with climate change will probably reduce the concentrations of N and C in global drylands, but increase that of P. These changes would uncouple the C, N and P cycles in drylands and could negatively affect the provision of key services provided by these ecosystems.
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In the last decade, research on irrigation has mainly been aimed at reducing crop water consumption. In arid and semi-arid environments, in relation to the limited water resources, the use of low quality water in agriculture has also been investigated in order to detect their effects on soil physical properties and on crop production. More recently, even the reduction of energy consumption in agriculture, as well as the effects of external factors, climate change and agricultural policies, have been major research interests. All these objectives have been considered in the papers included in this special issue. However, in the last years, approaches aimed at reducing crop water requirements have significantly changed. Remote sensing with satellites or unmanned vehicles, and vegetation spectral measurements, among others, represent in fact the newest frontier of existing technologies. Knowledge of soil hydraulic properties, often forgotten because of the difficulty of their estimation, can also be considered as a new way to reduce water consumption.
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Se realiza un estudio detallado del episodio cálido MIS 5 en la zona sureste de la Península Ibérica. Se realiza la reconstrucción paleoambiental a partir del estudio polínico y biomarcadores de un sondeo perforado en la costa de Almería. La cronología se estableció a partir del método de racemizaciónd e aminoácidos.Landwards of a MIS5 bar, a borehole core (SRA) was analyzed to establish the relationship between the lagoonal record and the raised beach deposits in the surroundings of the Antas river mouth and to reconstruct the Pleistocene palaeoenvironmental evolution 5 of the southern Mediterranean coast of the Iberian Peninsula. 63 samples were recovered for amino acid racemization dating, 86 samples for sedimentological and paleontological determination, 37 samples for pollen identification and 54 for biomarker analysis. AAR revealed that the borehole record contains MIS11, MIS6 and MIS5 deposits, the latter extensively represented. During the end of MIS6 and MIS5, a sand 10 barrier developed and created a shallow lagoon with alternating terrestrial inputs this process being common in other Mediterranean realms. Litho- and biofacies allowed the identification of distinct paleoenvironments through time, with the presence of a lagoonal environment alternating with alluvial fan progradation. Biomarkers indicated constant input from terrestrial plants, together with variable development of aquatic 15 macrophytes. The palynological content allowed the reconstruction of the paleoclimatological conditions during MIS6 and 5, with evidence of seven scenarios characterized by alternating arid and relatively humid conditions
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El presente trabajo de investigación aborda el tema del desarrollo regional en torno a una gran metrópoli como Bogotá y la Sabana de Bogotá. El crecimiento, expansión y relación con los municipios vecinos. Su entorno territorial; es un tema de discusión que cada día adquiere más fuerza desde hace varias décadas. Bogotá y la Sabana de Bogotá, se consideran en la actualidad como un caso representativo del caótico modelo de expansión urbana y crecimiento demográfico, enfrentado al desarrollo urbano como paradigma de la desigualdad de la ciudad latinoamericana. Son muchos los procesos y conflictos de naturaleza Regional y metropolitana que atraviesa la capital colombiana. Sin embargo esta investigación abordada el tema desde la necesidad de gobernanza y coordinación para el desarrollo territorial consensuado y equilibrado de la Región. La sabana de Bogotá está conformada por ciudades dormitorio, ciudades industriales, turísticas, agropecuarias, etc., es atravesada por el Río Bogotá, y en su centro la gran metrópoli, Bogotá D.C. centro de trabajo muy importante a nivel nacional, su área de influencia más próxima llega hasta: Caqueza, Zipaquira, Facatativa, Soacha, Fusagasuga y Girardot. Principales polos de desarrollo en la sabana y el departamento. Cundinamarca está compuesto por 15 provincias y Bogotá. Conformando un sistema de redes urbanas con necesidades comunes y demanda servicios públicos, de transporte, aseo, movilidad, salud, educación, espacio público y calidad ambiental. La metodología de esta investigación consiste en el análisis de la región a partir de la articulación de planes de ordenamiento territorial en un área de estudio propuesta. Mediante entrevistas con profesionales, expertos, funcionarios y empleados públicos y teniendo en cuenta las posibilidades legales en Colombia para el desarrollo territorial regional, establecer la situación real en materia de desarrollo para el departamento de Cundinamarca, evidenciando las necesidades del territorio y su desarrollo de una forma más compleja, valorando las sinergias y necesidades sociales, ambientales y económicas propias del crecimiento urbano, para proponer una serie de directrices que estructuren un desarrollo regional equilibrado en Bogotá y Cundinamarca. El análisis de los modelos del caso contribuye a fortalecer iniciativas para el desarrollo Regional de la Sabana de Bogotá como territorio sostenible: ambiental, económico y socialmente. En un sistema de redes que interconecte a Bogotá, con Cundinamarca, Colombia y el resto del mundo. Cundinamarca como región debe fijar estrategias y articular políticas en función de un modelo de desarrollo urbano regional para el departamento y la Sabana de Bogotá. Directrices departamentales básicas y fundamentales para el desarrollo territorial equilibrado que promueva ciudades sostenibles, compactas y con Calidad de vida para todos sus habitantes. ABSTRACT: This research addresses the issue of regional development around a big metropolis like Bogotá and Sabana de Bogota. The growth, expansion and relations with neighboring municipalities. Your local environment; It is an issue that becomes stronger every day for decades. Bogotá and Sabana de Bogotá, are considered today as a representative case of the chaotic model of urban expansion and population growth, urban development faced as a paradigm of inequality in Latin American city. Many processes and conflicts of Regional and metropolitan nature that crosses the Colombian capital. However this research addressed the issue from the need for governance and coordination for consensual and balanced territorial development of the region. The savannah of Bogota consists of bedroom communities, industrial cities, tourism, agriculture, etc., is crossed by the Bogota River, and at its center the great metropolis, Bogota DC center very important work at the national level, the area closest influence reaches: Caqueza, Zipaquira, Facatativa, Soacha, Fusagasuga and Girardot. Main centers of development in the savannah and the department. Cundinamarca is composed of 15 provinces and Bogota. Forming a system of urban networks with common needs and demand utilities, transportation, grooming, mobility, health, education, public space and environmental quality. The methodology of this research is the analysis of the region from the joint land use plans in the proposed study area. Through interviews with professionals, experts, public officials and employees and taking into account the legal possibilities in Colombia for regional territorial development, establish the real situation in development for the department of Cundinamarca, showing the region's needs and development of a more complex form, assessing synergies and own social, environmental and economic needs of urban growth, to propose a set of guidelines to structure a balanced regional development in Bogota and Cundinamarca. The analysis of case models helps to strengthen initiatives for regional development of the Sabana de Bogota and sustainable region: environmentally, economically and socially. In a network system that interconnects to Bogotá with Cundinamarca, Colombia and elsewhere. Cundinamarca region should set as joint strategies and policies based on a model of regional urban development for the department and the Sabana de Bogota. Basic and fundamental to balanced territorial development that fosters sustainable, compact and quality of life for all its inhabitants cities departmental guidelines.
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O posicionamento da maxila no esqueleto craniofacial tem sido motivo de investigação por diversos autores ao longo do tempo. Traduzindo suas idéias por meio de medidas lineares ou angulares, tais autores definiram o que consideraram como a posição ideal , normal , ou aceitável da maxila, relacionando-a, na maioria das vezes, com a base do crânio. A partir da avaliação de indivíduos com oclusão considerada normal e com bom equilíbrio facial, eram calculados valores médios e desvios-padrão de determinadas medidas, os quais eram tomados como parâmetros para avaliações cefalométricas de pacientes distintos. Diante das divergências de opiniões encontradas na literatura, a proposta do presente estudo foi avaliar o posicionamento da maxila nos sentidos vertical, ântero-posterior e a sua inclinação, numa amostra de 94 indivíduos com oclusão normal. Foram determinadas correlações entre medidas do próprio indivíduo: OPI-N com OPI-ENA e N-ENA com ENA-ENP. A partir dos fortes índices de correlação encontrados, concluiu-se que a medida OPI-N pode ser tomada como referência para determinação de OPI-ENA, da mesma forma que ENA-ENP pode ser considerada para determinação de N-ENA, definindo respectivamente a posição da maxila nos sentidos sagital e vertical. A inclinação da maxila, representada aqui pelo ângulo OPI.ENA.ENP, teve valor médio estatisticamente próximo a 0o (zero), indicando forte tendência do prolongamento posterior do plano palatino (ENA-ENP) tangenciar a base posterior do crânio (ponto OPI), o que se revela uma importante característica de indivíduos com oclusão normal.
Resumo:
O posicionamento da maxila no esqueleto craniofacial tem sido motivo de investigação por diversos autores ao longo do tempo. Traduzindo suas idéias por meio de medidas lineares ou angulares, tais autores definiram o que consideraram como a posição ideal , normal , ou aceitável da maxila, relacionando-a, na maioria das vezes, com a base do crânio. A partir da avaliação de indivíduos com oclusão considerada normal e com bom equilíbrio facial, eram calculados valores médios e desvios-padrão de determinadas medidas, os quais eram tomados como parâmetros para avaliações cefalométricas de pacientes distintos. Diante das divergências de opiniões encontradas na literatura, a proposta do presente estudo foi avaliar o posicionamento da maxila nos sentidos vertical, ântero-posterior e a sua inclinação, numa amostra de 94 indivíduos com oclusão normal. Foram determinadas correlações entre medidas do próprio indivíduo: OPI-N com OPI-ENA e N-ENA com ENA-ENP. A partir dos fortes índices de correlação encontrados, concluiu-se que a medida OPI-N pode ser tomada como referência para determinação de OPI-ENA, da mesma forma que ENA-ENP pode ser considerada para determinação de N-ENA, definindo respectivamente a posição da maxila nos sentidos sagital e vertical. A inclinação da maxila, representada aqui pelo ângulo OPI.ENA.ENP, teve valor médio estatisticamente próximo a 0o (zero), indicando forte tendência do prolongamento posterior do plano palatino (ENA-ENP) tangenciar a base posterior do crânio (ponto OPI), o que se revela uma importante característica de indivíduos com oclusão normal.
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A presente pesquisa tem como objetivo avaliar cefalometricamente, o espaço e po-sicionamento das coroas dos segundos e terceiros molares superiores permanentes não erupcionados na região da tuberosidade maxilar durante a distalização dos pri-meiros molares superiores, além de verificar a correlação entre estas duas variáveis. A amostra foi constituída de 38 telerradiografias em norma lateral direita, obtidas de 19 pacientes, jovens brasileiros, leucodermas e melanodermas, sendo 6 do sexo masculino e 13 do sexo feminino, com idade média de 9 anos 5 meses 13 dias. A metodologia constou inicialmente da divisão dos tempos (T1) inicial, e após a distali-zação do primeiro molar superior permanente em (T2) por um período médio de 10 meses e 23 dias. Para avaliação do espaço e angulação das coroas existente utili-zou-se uma Linha referencial intracraniana (Linha M) sendo esta demarcada, a partir de dois pontos, o ponto SE localizado na sutura esfenoetmoidal, e o ponto Pt locali-zado na parte anterior da fossa pterigopalatina. Esta linha referencial foi transferida até o ponto F, (Linha M ) ponto este localizado na região mais posterio-inferior da tuberosidade maxilar. O espaço avaliado compreendeu entre a Linha M , até a face distal do primeiro molar superior permanente. Na análise estatística usou-se o teste t (Teste t Student) , e na correlação entre espaço e angulação foi utilizado o coefi-ciente de correlação de Pearson. Concluímos que o espaço correspondente entre a distal dos primeiros molares superiores permanentes e extremidade da tuberosidade maxilar, na fase inicial e após a movimentação distal, não é suficiente para a erup-ção dos segundos e terceiros molares superiores permanentes. A angulação das coroas na fase inicial e após a movimentação distal posicionam-se com angulações mais para distal. Quanto à correlação das angulações das coroas dos segundos e terceiros molares superiores permanentes e o espaço para erupção verificamos que quanto maior a angulação das coroas para distal, menor os espaços oferecidos para a erupção.(AU)
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A presente pesquisa tem como objetivo avaliar cefalometricamente, o espaço e po-sicionamento das coroas dos segundos e terceiros molares superiores permanentes não erupcionados na região da tuberosidade maxilar durante a distalização dos pri-meiros molares superiores, além de verificar a correlação entre estas duas variáveis. A amostra foi constituída de 38 telerradiografias em norma lateral direita, obtidas de 19 pacientes, jovens brasileiros, leucodermas e melanodermas, sendo 6 do sexo masculino e 13 do sexo feminino, com idade média de 9 anos 5 meses 13 dias. A metodologia constou inicialmente da divisão dos tempos (T1) inicial, e após a distali-zação do primeiro molar superior permanente em (T2) por um período médio de 10 meses e 23 dias. Para avaliação do espaço e angulação das coroas existente utili-zou-se uma Linha referencial intracraniana (Linha M) sendo esta demarcada, a partir de dois pontos, o ponto SE localizado na sutura esfenoetmoidal, e o ponto Pt locali-zado na parte anterior da fossa pterigopalatina. Esta linha referencial foi transferida até o ponto F, (Linha M ) ponto este localizado na região mais posterio-inferior da tuberosidade maxilar. O espaço avaliado compreendeu entre a Linha M , até a face distal do primeiro molar superior permanente. Na análise estatística usou-se o teste t (Teste t Student) , e na correlação entre espaço e angulação foi utilizado o coefi-ciente de correlação de Pearson. Concluímos que o espaço correspondente entre a distal dos primeiros molares superiores permanentes e extremidade da tuberosidade maxilar, na fase inicial e após a movimentação distal, não é suficiente para a erup-ção dos segundos e terceiros molares superiores permanentes. A angulação das coroas na fase inicial e após a movimentação distal posicionam-se com angulações mais para distal. Quanto à correlação das angulações das coroas dos segundos e terceiros molares superiores permanentes e o espaço para erupção verificamos que quanto maior a angulação das coroas para distal, menor os espaços oferecidos para a erupção.(AU)
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The yeast translation factor eIF4G associates with both the cap-binding protein eIF4E and the poly(A)-binding protein Pab1p. Here we report that the two yeast eIF4G homologs, Tif4631p and Tif4632p, share a conserved Pab1p-binding site. This site is required for Pab1p and poly(A) tails to stimulate the in vitro translation of uncapped polyadenylylated mRNA, and the region encompassing it is required for the cap and the poly(A) tail to synergistically stimulate translation. This region on Tif4631p becomes essential for cell growth when the eIF4E binding site on Tif4631p is mutated. Pab1p mutations also show synthetic lethal interactions with eIF4E mutations. These data suggest that eIF4G mediates poly(A) tail stimulated translation in vitro, and that Pab1p and the domain encompassing the Pab1p-binding site on eIF4G can compensate for partial loss of eIF4E function in vivo.
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Vascular endothelial growth factor (VEGF) is a key regulator of developmental, physiological, and tumor angiogenesis. Upregulation of VEGF expression by hypoxia appears to be a critical step in the neovascularization of solid cancers. The VEGF mRNA is intrinsically labile, but in response to hypoxia the mRNA is stabilized. We have systematically analyzed the regions in the VEGF mRNA that are responsible for its lability under normoxic conditions and for stabilization in response to hypoxia. We find that the VEGF mRNA not only contains destabilizing elements in its 3′ untranslated region (3′UTR), but also contains destabilizing elements in the 5′UTR and coding region. Each region can independently promote mRNA degradation, and together they act additively to effect rapid degradation under normoxic conditions. Stabilization of the mRNA in response to hypoxia is completely dependent on the cooperation of elements in each of the 5′UTR, coding region, and 3′UTR. Combinations of any of two of these three regions were completely ineffective in responding to hypoxia, whereas combining all three regions allowed recapitulation of the hypoxic stabilization seen with the endogenous VEGF mRNA. We conclude that multiple regions in the VEGF mRNA cooperate both to ensure the rapid degradation of the mRNA under normoxic conditions and to allow stabilization of the mRNA in response to hypoxia. Our findings highlight the complexity of VEGF gene expression and also reveal a mechanism of gene regulation that could become the target for strategies of therapeutic intervention.
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Genetic recombination of plus-strand RNA viruses is an important process for promoting genetic variation. By using genetically marked poliovirus RNAs, we have demonstrated that genetic recombination can occur in a cell-free system that generates infective virus from added poliovirus RNA. Recombinant polioviruses were isolated, and the region of crossing over was roughly mapped. Recombinants could be isolated even under conditions where the yield of viruses from one of the parental RNAs was depressed to levels comparable to or less than the yield of recombinant viruses, an observation suggesting that only one of the recombining RNAs needs to be replication-competent. The generation of poliovirus recombinants in a cell-free system offers new possibilities for studying recombination and evolution of RNA viruses.
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Escherichia coli mRNA translation is facilitated by sequences upstream and downstream of the initiation codon, called Shine–Dalgarno (SD) and downstream box (DB) sequences, respectively. In E.coli enhancing the complementarity between the DB sequences and the 16S rRNA penultimate stem resulted in increased protein accumulation without a significant affect on mRNA stability. The objective of this study was to test whether enhancing the complementarity of plastid mRNAs downstream of the AUG (downstream sequence or DS) with the 16S rRNA penultimate stem (anti-DS or ADS region) enhances protein accumulation. The test system was the tobacco plastid rRNA operon promoter fused with the E.coli phage T7 gene 10 (T7g10) 5′-untranslated region (5′-UTR) and DB region. Translation efficiency was tested by measuring neomycin phosphotransferase (NPTII) accumulation in tobacco chloroplasts. We report here that the phage T7g10 5′-UTR and DB region promotes accumulation of NPTII up to ∼16% of total soluble leaf protein (TSP). Enhanced mRNA stability and an improved NPTII yield (∼23% of TSP) was obtained from a construct in which the T7g10 5′-UTR was linked with the NPTII coding region via a NheI site. However, replacing the T7g10 DB region with the plastid DS sequence reduced NPTII and mRNA levels to 0.16 and 28%, respectively. Reduced NPTII accumulation is in part due to accelerated mRNA turnover.