57 research outputs found
Downscaling With an Unstructured Coastal-Ocean Model to the Goro Lagoon and the Po River Delta Branches
The Goro Lagoon Finite Element Model (GOLFEM) presented in this paper concentrates on the high-resolution downscaled model of the Goro Lagoon, along with five Po river branches and the coastal area of the Po delta in the northern Adriatic Sea (Italy) where crucial socio-economic activities take place. GOLFEM was validated by means of validation scores (bias – BIAS, root mean square error – RMSE, and mean absolute error – MAE) for the water level, current velocity, salinity and temperature measured at several fixed stations in the lagoon. The range of scores at the stations are: for temperature between −0.8 to +1.2°C, for salinity from −0.2 to 5 PSU, for sea level 0.1 m. The lagoon is dominated by an estuarine vertical circulation due to a double opening at the lagoon mouth and sustained by multiple sources of freshwater inputs. The non-linear interactions among the tidal forcing, the wind and the freshwater inputs affect the lagoon circulation at both seasonal and daily time scales. The sensitivity of the circulation to the forcings was analyzed with several sensitivity experiments done with the exclusion of the tidal forcing and different configurations of the river connections. GOLFEM was designed to resolve the lagoon dynamics at high resolution in order to evaluate the potential effects on the clam farming of two proposed scenarios of human intervention on the morphology of the connection with the sea. We calculated the changes of the lagoon current speed and salinity, and using opportune fitness indexes related to the clams physiology, we quantified analytically the effects of the interventions in terms of extension and persistence of areas of the clams optimal growth. The results demonstrate that the correct management of this kind of fragile environment relies on both long-term (intervention scenarios) and short-term (coastal flooding forecasts and potential anoxic conditions) modeling, based on a flexible tool that is able to consider all the recorded human interventions on the river connections. This study also demonstrates the importance of designing a seamless chain of models that are capable of integrating local effects into the coarser operational oceanographic models
Mitochondrial echoes of first settlement and genetic continuity in El Salvador
Background: From Paleo-Indian times to recent historical episodes, the Mesoamerican isthmus played an important role in the distribution and patterns of variability all around the double American continent. However, the amount of genetic information currently available on Central American continental populations is very scarce. In order to shed light on the role of Mesoamerica in the peopling of the New World, the present study focuses on the analysis of the mtDNA variation in a population sample from El Salvador.
Methodology/Principal Findings: We have carried out DNA sequencing of the entire control region of the mitochondrial DNA (mtDNA) genome in 90 individuals from El Salvador. We have also compiled more than 3,985 control region profiles from the public domain and the literature in order to carry out inter-population comparisons. The results reveal a predominant Native American component in this region: by far, the most prevalent mtDNA haplogroup in this country (at ~90%) is A2, in contrast with other North, Meso- and South American populations. Haplogroup A2 shows a star-like phylogeny and is very diverse with a substantial proportion of mtDNAs (45%; sequence range 16090–16365) still unobserved in other American populations. Two different Bayesian approaches used to estimate admixture proportions in El Salvador shows that the majority of the mtDNAs observed come from North America. A preliminary founder analysis indicates that the settlement of El Salvador occurred about 13,400±5,200 Y.B.P.. The founder age of A2 in El Salvador is close to the overall age of A2 in America, which suggests that the colonization of this region occurred within a few thousand years of the initial expansion into the Americas.
Conclusions/Significance: As a whole, the results are compatible with the hypothesis that today's A2 variability in El Salvador represents to a large extent the indigenous component of the region. Concordant with this hypothesis is also the observation of a very limited contribution from European and African women (~5%). This implies that the Atlantic slave trade had a very small demographic impact in El Salvador in contrast to its transformation of the gene pool in neighbouring populations from the Caribbean facade
Recuperação de área degradada com sistema agroflorestal no Vale do Rio Doce, Minas Gerais.
O Vale do Rio Doce, MG, apresenta um histórico de ocupação e uso do solo que favorece a degradação ambiental, em que predominam pastagens sob o uso constante de queimadas. Os sistemas agroflorestais têm se mostrado eficientes na recuperação de áreas degradadas. Neste estudo foram avaliados os efeitos de um sistema agroflorestal na recuperação do solo em área degradada por pastagem na comunidade de Ilha Funda,Município de Periquito, Minas Gerais. A implantação do sistema se deu em 1994 e está sendo conduzido segundo os princípios agroecológicos, potencializando a regeneração natural e a sucessão de espécies. Em 1998, foram coletadas amostras de solo na área em recuperação e em duas áreas adjacentes: uma área degradada, que se encontrava em condições semelhantes às da área em recuperação no início do processo, e outra ocupada por pastagem. Foram determinados atributos químicos do solo e realizada a caracterização da matéria orgânica. O solo da área em recuperação com sistema agroflorestal mostrou-se em melhores condições do que o solo sob pastagem e o da área degradada, apresentando maior dinâmica do carbono orgânico e maior disponibilidade de nutrientes. Embora o teor de carbono orgânico total apresentado pelo solo sob pastagem tenha sido maior que nas demais condições avaliadas, o solo do sistema agroflorestal já está se igualando ao da pastagem no acúmulo das formas mais estáveis de carbono e apresentando maior dinâmica das frações orgânicas menos estáveis. Este estudo comprovou a eficiência dos sistemas agroflorestais, conduzidos segundo os princípios agroecológicos, na recuperação de áreas degradadas
Diversidad de artrópodos y sus enemigos naturales asociados al café (Coffea arabica L.) en El Salvador
El presente libro pretende dar un aporte en tal sentido, ofreciendo al lector una muestra de la diversidad de fauna invertebrada que se pueden encontrar en los cafetales bajo variados niveles de tecnificación y que en la mayoría de casos se ha logrado comprobar su cría a expensas del cultivo. Sin duda alguna que el esfuerzo no es del todo exhaustivo ya que existe mucha más diversidad por descubrir; pero es una muestra representativa del reto que representa el estudio de la fauna de artrópodos de este cultivo. En consecuencia se espera que motive al lector y a otros interesados en la temática, para profundizar en estos estudios de los cafetales y aumentar así el conocimiento de la entomología nacional. Por tanto, el presente libro ilustra los insectos, arañas y caracoles que están en poblaciones no dañinas que comprende 60 fotografías de arañas depredadoras y 350 fotografías de insectos entre fitófagos y benéficos (depredadores y parasitoides), con más de 200 especies de artrópodos asociados a los cafetales de El Salvador
Simulating the Impact on the Local Economy of Alternative Management Scenarios for Natural Areas
Creazione di una Banca dati ed elaborazione dei dati pregressi dello stato qualitativo della Sacca di Goro
Provincia di Ferrara Servizio Risorse idriche e Tutela Ambientale U:O:P:C: Acque costiere ed economia ittic
Política de inventarios máximos y mínimos en cadenas de suministro multinivel. Caso de estudio: una empresa de distribución farmacéutica (Artículo Profesional)
This research addresses the evaluation of the Min-Max inventory policy for serial supply chains. The study is conducted as a case study in a pharmaceutical distribution enterprise. The inventory policy is tested over the best-selling product of said company. In this study, the inventory policy is evaluated in terms of service level and inventory turn-over. A solution approach from the literature is compared with optimal or near optimal solutions. The optimization methods include, but are not limited to, Tabu Search and Scatter Search algorithms. Experimental results derived from simulations of the inventory policy demonstrate that the solution approach from the literature guarantees a high service level, but presents opportunities of improvement in terms of inventory turn-over.En este trabajo se aborda la evaluación de la política de inventarios máximos y mínimos en cadenas de suministros multinivel. La investigación se realiza con base en la metodología de estudio de caso en una empresa de distribución farmacéutica. Se utiliza el producto con mayor nivel de ventas de la empresa para evaluar la política de inventarios. En este estudio la política de inventarios es evaluada mediante los indicadores de nivel de servicio y rotación de inventarios. Una solución derivada de la teoría es comparada con soluciones óptimas o cercanas a la óptima. Los métodos de optimización incluyen, pero no están limitados a, algoritmos de búsqueda tabú y búsqueda dispersa. Resultados experimentales derivados de las simulaciones de la política de inventarios demuestran que la solución derivada de la teoría garantiza un alto nivel de servicio, pero presenta oportunidades de mejora en términos de la rotación de inventarios
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