943 resultados para Guidelines for Handling Web Resources on CUNY and the Web
Resumo:
The Web has witnessed an enormous growth in the amount of semantic information published in recent years. This growth has been stimulated to a large extent by the emergence of Linked Data. Although this brings us a big step closer to the vision of a Semantic Web, it also raises new issues such as the need for dealing with information expressed in different natural languages. Indeed, although the Web of Data can contain any kind of information in any language, it still lacks explicit mechanisms to automatically reconcile such information when it is expressed in different languages. This leads to situations in which data expressed in a certain language is not easily accessible to speakers of other languages. The Web of Data shows the potential for being extended to a truly multilingual web as vocabularies and data can be published in a language-independent fashion, while associated language-dependent (linguistic) information supporting the access across languages can be stored separately. In this sense, the multilingual Web of Data can be realized in our view as a layer of services and resources on top of the existing Linked Data infrastructure adding i) linguistic information for data and vocabularies in different languages, ii) mappings between data with labels in different languages, and iii) services to dynamically access and traverse Linked Data across different languages. In this article we present this vision of a multilingual Web of Data. We discuss challenges that need to be addressed to make this vision come true and discuss the role that techniques such as ontology localization, ontology mapping, and cross-lingual ontology-based information access and presentation will play in achieving this. Further, we propose an initial architecture and describe a roadmap that can provide a basis for the implementation of this vision.
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El manejo pre-sacrificio es de vital importancia en acuicultura, ya que afecta tanto a las reacciones fisiolgicas como a los procesos bioqumicos post mortem, y por tanto al bienestar y a la calidad del producto. El ayuno pre-sacrificio se lleva a cabo de forma habitual en acuicultura, ya que permite el vaciado del aparato digestivo de restos de alimento y heces, reduciendo de esta manera la carga bacteriana en el intestino y la dispersin de enzimas digestivos y potenciales patgenos a la carne. Sin embargo, la duracin ptima de este ayuno sin que el pez sufra un estrs innecesario no est clara. Adems, se sabe muy poco sobre la mejor hora del da para realizar el sacrificio, lo que a su vez est regido por los ritmos diarios de los parmetros fisiolgicos de estrs. Finalmente, se sabe que la temperatura del agua juega un papel muy importante en la fisiologa del estrs pero no se ha determinado su efecto en combinacin con el ayuno. Adems, las actuales recomendaciones en relacin a la duracin ptima del ayuno previo al sacrificio en peces no suelen considerar la temperatura del agua y se basan nicamente en das y no en grados da (C d). Se determin el efecto del ayuno previo al sacrificio (1, 2 y 3 das, equivalente a 11,1-68,0 grados da) y la hora de sacrificio (08h00, 14h00 y 20h00) en trucha arco iris (Oncorhynchus mykiss) de tamao comercial en cuatro pruebas usando diferentes temperaturas de agua (Prueba 1: 11,8 C; Prueba 2: 19,2 C; Prueba 3: 11,1 C; y Prueba 4: 22,7 C). Se midieron indicadores biomtricos, hematolgicos, metablicos y de calidad de la carne. En cada prueba, los valores de los animales ayunados (n=90) se compararon con 90 animales control mantenidos bajo condiciones similares pero nos ayunados. Los resultados sugieren que el ayuno tuvo un efecto significativo sobre los indicadores biomtricos. El coeficiente de condicin en los animales ayunados fue menor que en los controles despus de 2 das de ayuno. El vaciado del aparato digestivo se produjo durante las primeras 24 h de ayuno, encontrndose pequeas cantidades de alimento despus de 48 h. Por otra parte, este vaciado fue ms rpido cuando las temperaturas fueron ms altas. El peso del hgado de los animales ayunados fue menor y las diferencias entre truchas ayunadas y controles fueron ms evidentes a medida que el vaciado del aparato digestivo fue ms rpido. El efecto del ayuno hasta 3 das en los indicadores hematolgicos no fue significativo. Los niveles de cortisol en plasma resultaron ser altos tanto en truchas ayunadas como en las alimentadas en todas las pruebas realizadas. La concentracin media de glucosa vari entre pruebas pero mostr una tendencia a disminuir en animales ayunados a medida que el ayuno progresaba. En cualquier caso, parece que la temperatura del agua jug un papel muy importante, ya que se encontraron concentraciones ms altas durante los das 2 y 3 de ayuno en animales mantenidos a temperaturas ms bajas previamente al sacrificio. Los altos niveles de lactato obtenidos en sangre parecen sugerir episodios de intensa actividad muscular pero no se pudo encontrar relacin con el ayuno. De la misma manera, el nivel de hematocrito no mostr efecto alguno del ayuno y los leucocitos tendieron a ser ms altos cuando los animales estaban menos estresados y cuando su condicin corporal fue mayor. Finalmente, la disminucin del peso del hgado (ndice hepatosomtico) en la Prueba 3 no se vio acompaada de una reduccin del glucgeno heptico, lo que sugiere que las truchas emplearon una estrategia diferente para mantener constantes los niveles de glucosa durante el periodo de ayuno en esa prueba. En relacin a la hora de sacrificio, se obtuvieron niveles ms bajos de cortisol a las 20h00, lo que indica que las truchas estaban menos estresadas y que el manejo pre-sacrificio podra resultar menos estresante por la noche. Los niveles de hematocrito fueron tambin ms bajos a las 20h00 pero solo con temperaturas ms bajas, sugiriendo que las altas temperaturas incrementan el metabolismo. Ni el ayuno ni la hora de sacrificio tuvieron un efecto significativo sobre la evolucin de la calidad de la carne durante los 3 das de almacenamiento. Por el contrario, el tiempo de almacenamiento s que parece tener un efecto claro sobre los parmetros de calidad del producto final. Los niveles ms bajos de pH se alcanzaron a las 24-48 h post mortem, con una lata variabilidad entre duraciones del ayuno (1, 2 y 3 das) en animales sacrificados a las 20h00, aunque no se pudo distinguir ningn patrn comn. Por otra parte, la mayor rigidez asociada al rigor mortis se produjo a las 24 h del sacrificio. La capacidad de retencin de agua se mostr muy estable durante el perodo de almacenamiento y parece ser independiente de los cambios en el pH. El parmetro L* de color se increment a medida que avanzaba el perodo de almacenamiento de la carne, mientras que los valores a* y b* no variaron en gran medida. En conclusin, basndose en los resultados hematolgicos, el sacrificio a ltima hora del da parece tener un efecto menos negativo en el bienestar. De manera general, nuestros resultados sugieren que la trucha arco iris puede soportar un perodo de ayuno previo al sacrificio de hasta 3 das o 68 C d sin que su bienestar se vea seriamente comprometido. Es probable que con temperaturas ms bajas las truchas pudieran ser ayunadas durante ms tiempo sin ningn efecto negativo sobre su bienestar. En cualquier caso, se necesitan ms estudios para determinar la relacin entre la temperatura del agua y la duracin ptima del ayuno en trminos de prdida de peso vivo y la disminucin de los niveles de glucosa en sangre y otros indicadores metablicos. SUMMARY Pre-slaughter handling in fish is important because it affects both physiological reactions and post mortem biochemical processes, and thus welfare and product quality. Pre-slaughter fasting is regularly carried out in aquaculture, as it empties the viscera of food and faeces, thus reducing the intestinal bacteria load and the spread of gut enzymes and potential pathogens to the flesh. However, it is unclear how long rainbow trout can be fasted before suffering unnecessary stress. In addition, very little is known about the best time of the day to slaughter fish, which may in turn be dictated by diurnal rhythms in physiological stress parameters. Water temperature is also known to play a very important role in stress physiology in fish but the combined effect with fasting is unclear. Current recommendations regarding the optimal duration of pre-slaughter fasting do not normally consider water temperature and are only based on days, not degree days (C d). The effects of short-term fasting prior to slaughter (1, 2 and 3 days, between 11.1 and 68.0 C days) and hour of slaughter (08h00, 14h00 and 20h00) were determined in commercial-sized rainbow trout (Oncorhynchus mykiss) over four trials at different water temperatures (TRIAL 1, 11.8 C; TRIAL 2, 19.2 C; TRIAL 3, 11.1 C; and TRIAL 4, 22.7 C). We measured biometric, haematological, metabolic and product quality indicators. In each trial, the values of fasted fish (n=90) were compared with 90 control fish kept under similar conditions but not fasted. Results show that fasting affected biometric indicators. The coefficient of condition in fasted trout was lower than controls 2 days after food deprivation. Gut emptying occurred within the first 24 h after the cessation of feeding, with small traces of digesta after 48 h. Gut emptying was faster at higher water temperatures. Liver weight decreased in food deprived fish and differences between fasted and fed trout were more evident when gut clearance was faster. The overall effect of fasting for up to three days on haematological indicators was small. Plasma cortisol levels were high in both fasted and fed fish in all trials. Plasma glucose response to fasting varied among trials, but it tended to be lower in fasted fish as the days of fasting increased. In any case, it seems that water temperature played a more important role, with higher concentrations at lower temperatures on days 2 and 3 after the cessation of feeding. Plasma lactate levels indicate moments of high muscular activity and were also high, but no variation related to fasting could be found. Haematocrit did not show any significant effect of fasting, but leucocytes tended to be higher when trout were less stressed and when their body condition was higher. Finally, the loss of liver weight was not accompanied by a decrease in liver glycogen (only measured in TRIAL 3), suggesting that a different strategy to maintain plasma glucose levels was used. Regarding the hour of slaughter, lower cortisol levels were found at 20h00, suggesting that trout were less stressed later in the day and that pre-slaughter handling may be less stressful at night. Haematocrit levels were also lower at 20h00 but only at lower temperatures, indicating that higher temperatures increase metabolism. Neither fasting nor the hour of slaughter had a significant effect on the evolution of meat quality during 3 days of storage. In contrast, storage time seemed to have a more important effect on meat quality parameters. The lowest pH was reached 24-48 h post mortem, with a higher variability among fasting durations at 20h00, although no clear pattern could be discerned. Maximum stiffening from rigor mortis occurred after 24 h. The water holding capacity was very stable throughout storage and seemed to be independent of pH changes. Meat lightness (L*) slightly increased during storage and a* and b*-values were relatively stable. In conclusion, based on the haematological results, slaughtering at night may have less of a negative effect on welfare than at other times of the day. Overall, our results suggest that rainbow trout can cope well with fasting up to three days or 68 C d prior to slaughter and that their welfare is therefore not seriously compromised. At low water temperatures, trout could probably be fasted for longer periods without negative effects on welfare but more research is needed to determine the relationship between water temperature and days of fasting in terms of loss of live weight and the decrease in plasma glucose and other metabolic indicators.
Resumo:
Thermorheological changes in high hydrostatic pressure (HHP)-treated chickpea flour (CF) slurries were studied as a function of pressure level (0.1, 150, 300, 400, and 600 MPa) and slurry concentration (1:5, 1:4, 1:3, and 1:2 flour-to-water ratios). HHP-treated slurries were subsequently analyzed for changes in properties produced by heating, under both isothermal and non-isothermal processes. Elasticity (G) of pressurized slurry increased with pressure applied and concentration. Conversely, heat-induced CF paste gradually transformed from solid-like behavior to liquid-like behavior as a function of moisture content and pressure level. The G and enthalpy of the CF paste decreased with increasing pressure level in proportion with the extent of HHP-induced starch gelatinization. At 25 C and 15 min, HHP treatment at 450 and 600 MPa was sufficient to complete gelatinization of CF slurry at the lowest concentration (1:5), while more concentrated slurries would require higher pressures and temperature during treatment or longer holding times. Industrial relevance Demand for chickpea gel has increased considerably in the health and food industries because of its many beneficial effects. However, its use is affected by its very difficult handling. Judicious application of high hydrostatic pressure (HHP) at appropriate levels, adopted as a pre-processing instrument in combination with heating processes, is presented as an innovative technology to produce a remarkable decrease in thermo-hardening of heat-induced chickpea flour paste, permitting the development of new chickpea-based products with desirable handling properties and sensory attributes.
Analysis of a rate-adaptive reconciliation protocol and the effect of leakage on the secret key rate
Resumo:
Quantum key distribution performs the trick of growing a secret key in two distant places connected by a quantum channel. The main reason is so that the legitimate users can bound the information gathered by the eavesdropper. In practical systems, whether because of finite resources or external conditions, the quantum channel is subject to fluctuations. A rate-adaptive information reconciliation protocol, which adapts to the changes in the communication channel, is then required to minimize the leakage of information in the classical postprocessing. We consider here the leakage of a rate-adaptive information reconciliation protocol. The length of the exchanged messages is larger than that of an optimal protocol; however, we prove that the min-entropy reduction is limited. The simulation results, both in the asymptotic and in the finite-length regime, show that this protocol allows to increase the amount of a distillable secret key.
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Farmers in Africa are facing climate change and challenging rural livelihoods while maintaining agricultural systems that are not resilient. By 2050 the mean estimates of production of key staple crops in Africa such as maize, sorghum, millet, groundnut, and cassava are expected to decrease by between 8 and 22 percent (Schlenker and Lobell 2010). In Kenya, although projections of rainfall do not show dramatic decreases, the distribution of impacts is clearly negative for most crops. As increases in temperature will lead to increases in evapotranspiration, a potential increase in rainfall in Kenya may not offset the expected increases in agricultural water needs (Herrero et al. 2010). In order to respond to these present and future challenges, potential mitigation and adaptation options have been developed. However, implementation is not evident. In addition to their benefits in either mitigating or reducing the vulnerability of climate change effects, many of these options do not have economic costs and even provide economic benefits (e.g. savings in the consumption of energy or natural resources). Nevertheless, it is demonstrated that even when there are no biophysical, technological or economic constraints and despite their potential benefits from either the economic or environmental climate change point of view, not all farmers are willing to adopt these measures. This reflects the key role that behavioural barriers can play in the uptake of mitigation and adaptation measures.
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A nonlinear implicit finite element model for the solution of two-dimensional (2-D) shallow water equations, based on a Galerkin formulation of the 2-D estuaries hydrodynamic equations, has been developed. Spatial discretization has been achieved by the use of isoparametric, Lagrangian elements. To obtain the different element matrices, Simpson numerical integration has been applied. For time integration of the model, several schemes in finite differences have been used: the Cranck-Nicholson iterative method supplies a superior accuracy and allows us to work with the greatest time step t; however, central differences time integration produces a greater velocity of calculation. The model has been tested with different examples to check its accuracy and advantages in relation to computation and handling of matrices. Finally, an application to the Bay of Santander is also presented.
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Recent commentaries have proposed the advantages of using open exchange of data and informatics resources for improving health-related policies and patient care in Africa. Yet, in many African regions, both private medical and public health information systems are still unaffordable. Open exchange over the social Web 2.0 could encourage more altruistic support of medical initiatives. We have carried out some experiments to demonstrate the feasibility of using this approach to disseminate open data and informatics resources in Africa. After the experiments we developed the AFRICA BUILD Portal, the first Social Network for African biomedical researchers. Through the AFRICA BUILD Portal users can access in a transparent way to several resources. Currently, over 600 researchers are using distributed and open resources through this platform committed to low connections.
Resumo:
Vivimos una poca en la que el mundo se transforma aceleradamente. La globalizacin est siguiendo un curso imparable, la poblacin mundial as como la poblacin urbana siguen creciendo, y en los pases emergentes los ingresos promedios aumentan, resultando en un cambio tambin acelerado de las dietas y hbitos alimentarios. En conjunto esos factores estn causando un aumento fundamental de la demanda de alimentos. Junto con la apertura de los mercados agrcolas, estos procesos han provocado un crecimiento del comercio internacional de alimentos durante la ltima dcada. Dado que muchos pases de Amrica Latina estn dotados de abundancia de recursos naturales, estas tendencias han producido un crecimiento rpido de las exportaciones de bienes primarios desde Amrica Latina al resto del mundo. En slo 30 aos la participacin en el mercado agrcola de Amrica Latina casi se ha duplicado, desde 10% en 1980 a 18% en 2010. Este aumento del comercio agrcola ha dado lugar a un debate sobre una serie de cuestiones cruciales relacionadas con los impactos del comercio en la seguridad alimentaria mundial, en el medio ambiente o en la reduccin de la pobreza rural en pases en desarrollo. Esta tesis aplica un marco integrado para analizar varios impactos relacionados con la transformacin de los mercados agrcolas y los mercados rurales debidos a la globalizacin y, en particular, al progresivo aumento del comercio internacional. En concreto, la tesis aborda los siguientes temas: En primer lugar, la produccin mundial de alimentos tendr que aumentar considerablemente para poder satisfacer la demanda de una poblacin mundial de 9000 millones personas en 2050, lo cual plantea grandes desafos sobre los sistemas de la produccin de alimentos. Alcanzar este logro, sin comprometer la integridad del medio ambiente en regiones exportadoras, es un reto an mayor. En este contexto, la tesis analiza los efectos de la liberalizacin del comercio mundial, considerando distintas tecnologas de produccin agraria, sobre unos indicadores de seguridad alimentaria en diferentes regiones del mundo y sobre distintos indicadores ambientales, teniendo en cuenta escalas diferentes en Amrica Latina y el Caribe. La tesis utiliza el modelo International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) un modelo dinmico de equilibrio parcial del sector agrcola a escala global para modelar la apertura de los mercados agrcolas as como diferentes escenarios de la produccin hasta el ao 2050. Los resultados del modelo estn vinculados a modelos biofsicos para poder evaluar los cambios en la huella hdrica y la calidad del agua, as como para cuantificar los impactos del cambio en el uso del suelo sobre la biodiversidad y los stocks de carbono en 2050. Los resultados indican que la apertura de los mercados agrcolas es muy importante para mejorar la seguridad alimentaria a nivel mundial, sin embargo, produce tambin presiones ambientales indeseables en algunas regiones de Amrica Latina. Contrastando dos escenarios que consideran distintas modos de produccin, la expansin de la tierra agrcola frente a un escenario de la produccin ms intensiva, se demuestra que las mejoras de productividad son generalmente superiores a la expansin de las tierras agrcolas, desde un punto de vista econmico e ambiental. En cambio, los escenarios de intensificacin sostenible no slo hacen posible una mayor produccin de alimentos, sino que tambin generan menos impactos medioambientales que los otros escenarios futuros en todas sus dimensiones: biodiversidad, carbono, emisiones de nitratos y uso del agua. El anlisis muestra que hay un trade-off entre el objetivo de alcanzar la sostenibilidad ambiental y el objetivo de la seguridad alimentaria, independiente del manejo agrcola en el futuro. En segundo lugar, a la luz de la reciente crisis de los precios de alimentos en los aos 2007/08, la tesis analiza los impactos de la apertura de los mercados agrcolas en la transmisin de precios de los alimentos en seis pases de Amrica Latina: Argentina, Brasil, Chile, Colombia, Mxico y el Per. Para identificar las posibles relaciones de cointegracin entre los ndices de precios al consumidor de alimentos y los ndices de precios de agrarios internacionales, sujetos a diferentes grados de apertura de mercados agrcolas en los seis pases de Amrica Latina, se utiliza un modelo simple de correccin de error (single equation error correction). Los resultados indican que la integracin global de los mercados agrcolas ha dado lugar a diferentes tasas de transmisin de precios en los pases investigados. Sobre todo en el corto plazo, las tasas de transmisin dependen del grado de apertura comercial, mientras que en el largo plazo las tasas de transmisin son elevadas, pero en gran medida independientes del rgimen de comercio. Por lo tanto, durante un perodo de shocks de precios mundiales una mayor apertura del comercio trae consigo ms inestabilidad de los precios domsticos a corto plazo y la resultante persistencia en el largo plazo. Sin embargo, estos resultados no verifican necesariamente la utilidad de las polticas comerciales, aplicadas frecuentemente por los gobiernos para amortiguar los shocks de precios. Primero, porque existe un riesgo considerable de volatilidad de los precios debido a cambios bruscos de la oferta nacional si se promueve la autosuficiencia en el pas; y segundo, la poltica de proteccionismo asume el riesgo de excluir el pas de participar en las cadenas de suministro de alto valor del sector agrcola, y por lo tanto esa poltica podra obstaculizar el desarrollo econmico. Sin embargo, es indispensable establecer polticas efectivas para reducir la vulnerabilidad de los hogares a los aumentos repentinos de precios de alimentos, lo cual requiere una planificacin gubernamental precisa con el presupuesto requerido disponible. En tercer lugar, la globalizacin afecta a la estructura de una economa y, por medios distintos, la distribucin de los ingreso en un pas. Per sirve como ejemplo para investigar ms profundamente las cuestiones relacionadas con los cambios en la distribucin de los ingresos en zonas rurales. Per, que es un pas que est cada vez ms integrado en los mercados mundiales, consigui importantes descensos en la pobreza extrema en sus zonas rurales, pero a la vez adolece de alta incidencia de pobreza moderada y de desigualdad de los ingresos en zonas rural al menos durante el periodo comprendido entre 2004 y 2012. Esta parte de la tesis tiene como objetivo identificar las fuerzas impulsoras detrs de estas dinmicas en el Per mediante el uso de un modelo de microsimulacin basado en modelos de generacin de ingresos aplicado a nivel los hogares rurales. Los resultados indican que la fuerza principal detrs de la reduccin de la pobreza ha sido el crecimiento econmico general de la economa, debido a las condiciones macroeconmicas favorables durante el periodo de estudio. Estos efectos de crecimiento beneficiaron a casi todos los sectores rurales, y dieron lugar a la disminucin de la pobreza rural extrema, especialmente entre los agricultores de papas y de maz. En parte, estos agricultores probablemente se beneficiaron de la apertura de los mercados agrcolas, que es lo que podra haber provocado un aumento de los precios al productor en tiempos de altos precios mundiales de los alimentos. Sin embargo, los resultados tambin sugieren que para una gran parte de la poblacin ms pobre existan barreras de entrada a la hora de poder participar en el empleo asalariado fuera de la agricultura o en la produccin de cultivos de alto valor. Esto podra explicarse por la falta de acceso a unos activos importantes: por ejemplo, el nivel de educacin de los pobres era apenas mejor en 2012 que en 2004; y tambin las dotaciones de tierra y de mano de obra, sobre todo de los productores pobres de maz y patata, disminuyeron entre 2004 y 2012. Esto lleva a la conclusin de que an hay margen para aplicar polticas para facilitar el acceso a estos activos, que podra contribuir a la erradicacin de la pobreza rural. La tesis concluye que el comercio agrcola puede ser un importante medio para abastecer una poblacin mundial creciente y ms rica con una cantidad suficiente de caloras. Para evitar adversos efectos ambientales e impactos negativos para los consumidores y de los productores pobres, el enfoque debe centrarse en las mejoras de la productividad agrcola, teniendo en cuenta los lmites ambientales y ser socialmente inclusivo. En este sentido, ser indispensable seguir desarrollando soluciones tecnolgicas que garanticen prcticas de produccin agrcola minimizando el uso de recursos naturales. Adems, para los pequeos pobres agricultores ser fundamental eliminar las barreras de entrada a los mercados de exportacin que podra tener efectos indirectos favorables a travs de la adopcin de nuevas tecnologas alcanzables a travs de mercados internacionales. ABSTRACT The world is in a state of rapid transition. Ongoing globalization, population growth, rising living standards and increasing urbanization, accompanied by changing dietary patterns throughout the world, are increasing the demand for food. Together with more open trade regimes, this has triggered growing international agricultural trade during the last decade. For many Latin American countries, which are gifted with relative natural resource abundance, these trends have fueled rapid export growth of primary goods. In just 30 years, the Latin American agricultural market share has almost doubled from 10% in 1980 to 18% in 2010. These market developments have given rise to a debate around a number of crucial issues related to the role of agricultural trade for global food security, for the environment or for poverty reduction in developing countries. This thesis uses an integrated framework to analyze a broad array of possible impacts related to transforming agricultural and rural markets in light of globalization, and in particular of increasing trade activity. Specifically, the following issues are approached: First, global food production will have to rise substantially by the year 2050 to meet effective demand of a nine billion people world population which poses major challenges to food production systems. Doing so without compromising environmental integrity in exporting regions is an even greater challenge. In this context, the thesis explores the effects of future global trade liberalization on food security indicators in different world regions and on a variety of environmental indicators at different scales in Latin America and the Caribbean, in due consideration of different future agricultural production practices. The International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT) a global dynamic partial equilibrium model of the agricultural sector developed by the International Food Policy Research Institute (IFPRI) is applied to run different future production scenarios, and agricultural trade regimes out to 2050. Model results are linked to biophysical models, used to assess changes in water footprints and water quality, as well as impacts on biodiversity and carbon stocks from land use change by 2050. Results indicate that further trade liberalization is crucial for improving food security globally, but that it would also lead to more environmental pressures in some regions across Latin America. Contrasting land expansion versus more intensified agriculture shows that productivity improvements are generally superior to agricultural land expansion, from an economic and environmental point of view. Most promising for achieving food security and environmental goals, in equal measure, is the sustainable intensification scenario. However, the analysis shows that there are trade-offs between environmental and food security goals for all agricultural development paths. Second, in light of the recent food price crisis of 2007/08, the thesis looks at the impacts of increasing agricultural market integration on food price transmission from global to domestic markets in six Latin American countries, namely Argentina, Brazil, Chile, Colombia, Mexico and Peru. To identify possible cointegrating relationships between the domestic food consumer price indices and world food price levels, subject to different degrees of agricultural market integration in the six Latin American countries, a single equation error correction model is used. Results suggest that global agricultural market integration has led to different levels of price path-through in the studied countries. Especially in the short-run, transmission rates depend on the degree of trade openness, while in the long-run transmission rates are high, but largely independent of the country-specific trade regime. Hence, under world price shocks more trade openness brings with it more price instability in the short-term and the resulting persistence in the long-term. However, these findings do not necessarily verify the usefulness of trade policies, often applied by governments to buffer such price shocks. First, because there is a considerable risk of price volatility due to domestic supply shocks if self-sufficiency is promoted. Second, protectionism bears the risk of excluding a country from participating in beneficial high-value agricultural supply chains, thereby hampering economic development. Nevertheless, to reduce households vulnerability to sudden and large increases of food prices, effective policies to buffer food price shocks should be put in place, but must be carefully planned with the required budget readily available. Third, globalization affects the structure of an economy and, by different means, the distribution of income in a country. Peru serves as an example to dive deeper into questions related to changes in the income distribution in rural areas. Peru, a country being increasingly integrated into global food markets, experienced large drops in extreme rural poverty, but persistently high rates of moderate rural poverty and rural income inequality between 2004 and 2012. The thesis aims at disentangling the driving forces behind these dynamics by using a microsimulation model based on rural household income generation models. Results provide evidence that the main force behind poverty reduction was overall economic growth of the economy due to generally favorable macroeconomic market conditions. These growth effects benefited almost all rural sectors, and led to declines in extreme rural poverty, especially among potato and maize farmers. In part, these farmers probably benefited from policy changes towards more open trade regimes and the resulting higher producer prices in times of elevated global food price levels. However, the results also suggest that entry barriers existed for the poorer part of the population to participate in well-paid wage-employment outside of agriculture or in high-value crop production. This could be explained by a lack of sufficient access to important rural assets. For example, poor peoples educational attainment was hardly better in 2012 than in 2004. Also land and labor endowments, especially of (poor) maize and potato growers, rather decreased than increased over time. This leads to the conclusion that there is still scope for policy action to facilitate access to these assets, which could contribute to the eradication of rural poverty. The thesis concludes that agricultural trade can be one important means to provide a growing and richer world population with sufficient amounts of calories. To avoid adverse environmental effects and negative impacts for poor food consumers and producers, the focus should lie on agricultural productivity improvements, considering environmental limits and be socially inclusive. In this sense, it will be crucial to further develop technological solutions that guarantee resource-sparing agricultural production practices, and to remove entry barriers for small poor farmers to export markets which might allow for technological spill-over effects from high-value global agricultural supply chains.
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Background: This projects idea arose derived of the need of the professors of the department Computer Languages and Systems and Software Engineering (DLSIIS) to develop exams with multiple choice questions in a more productive and comfortable way than the one they are currently using. The goal of this project is to develop an application that can be easily used by the professors of the DLSIIS when they need to create a new exam. The main problems of the previous creation process were the difficulty in searching for a question that meets some specific conditions in the previous exam files; and the difficulty for editing exams because of the format of the employed text files. Result: The results shown in this document allow the reader to understand how the final application works and how it addresses successfully every customer need. The elements that will help the reader to understand the application are the structure of the application, the design of the different components, diagrams that show the workflow of the application and some selected fragments of code. Conclusions: The goals stated in the application requirements are finally met. In addition, there are some thoughts about the work performed during the development of the application and how it improved the author skills in web development.
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Some islands in the Gulf of California support very high densities of spiders. Spider density is negatively correlated with island size; many small islands support 50-200 spiders per m3 of cactus. Energy for these spiders comes primarily from the ocean and not from in situ productivity by land plants. We explicitly connect the marine and terrestrial systems to show that insular food webs represent one endpoint of the marine web. We describe two conduits for marine energy entering these islands: shore drift and seabird colonies. Both conduits are related to island area, having a much stronger effect on smaller islands. This asymmetric effect helps to explain the exceptionally high spider densities on small islands. Although productivity sets the maximal potential densities, predation (by scorpions) limits realized spider abundance. Thus, prey availability and predation act in concert to set insular spider abundance.
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Different kinds of algorithms can be chosen so as to compute elementary functions. Among all of them, it is worthwhile mentioning the shift-and-add algorithms due to the fact that they have been specifically designed to be very simple and to save computer resources. In fact, almost the only operations usually involved with these methods are additions and shifts, which can be easily and efficiently performed by a digital processor. Shift-and-add algorithms allow fairly good precision with low cost iterations. The most famous algorithm belonging to this type is CORDIC. CORDIC has the capability of approximating a wide variety of functions with only the help of a slight change in their iterations. In this paper, we will analyze the requirements of some engineering and industrial problems in terms of type of operands and functions to approximate. Then, we will propose the application of shift-and-add algorithms based on CORDIC to these problems. We will make a comparison between the different methods applied in terms of the precision of the results and the number of iterations required.
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This study analyzes the traffic generated on YouTube around television series. We selected a sample of 314 short YouTube videos about 21 Spanish TV series that premiered in 2013 by Spains three most popular mainstream television networks (Telecinco, Antena 3, and La1). These videos, which together received more than 24 million views, were classified according to two key variables: the nature (official or nonofficial) of the YouTube channel on which they were located and the exclusivity of their content (already broadcast on TV or Web exclusive). The analysis allows us to characterize the strategies used by TV networks on YouTube and the activity of fans as well as their efforts in the construction of a transmedia narrative universe around TV series.
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At first glance the Aliens Restriction Act of 1914, which was introduced and passed on the first day of World War One, seems a hasty and ill-prepared piece of legislation. Actually, when examined in the light of Arthur Marwick's thesis that war is a forcing house for pre-existent social and governmental ideas, it becomes clear that the act was not after all the product of hastily formed notions. In point of fact it followed the precedent of detailed draft clauses produced in 1911 by a sub-committee of the Committee of Imperial Defence established to consider the treatment of aliens in the event of war. Indeed the draft clauses and the restrictions embodied in the 1914 act were strikingly similar to restrictions on aliens legislated in 1793. Hostility to aliens had been growing from 1905 to 1914 and this hostility blossomed into xeno-phobia on the outbreak of war, a crucial precondition for the specifically anti-enemy fears of the time. In 1919 the Aliens Restriction (Amendment) Bill was introduced into parliament to extend temporarily the provisions of the 1914 act thus permitting the Home Secretary to plan permanent, detailed legislation. Two minority groups of MPs with extreme views on the treatment of aliens were prominent in the debates on this bill. The extreme Liberal group which advocated leniency in the treatment of aliens had little effect on the final form of the bill, but the extreme Conservative group, which demanded severe restrictions on aliens, succeeded in persuading the government to include detailed restrictions. Despite its allegedly temporary nature, the Aliens Restriction (Amendment) Act of 1919 was renewed annually until 1971.
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This paper was prepared as a Policy Brief for discussion at the final conference of the project on Involuntary Loss of European Citizenship: Exchanging Knowledge and Identifying Guidelines for Europe, 11-12 December 2014. Co-funded by the European Commissions DG for Justice, Citizenship and Fundamental Rights, the ILEC project has aimed to establish a framework for debate on international norms on involuntary loss of nationality. For more information visit: www.ilecproject.eu.
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In recent weeks, Rosneft, a Russian state-owned oil company, has signed co-operation agreements with three Western corporations: Americas ExxonMobil, Italys Eni, and Norways Statoil. In exchange for access to Russian oil fields on the continental shelf as minority shareholders, these Western investors will finance and carry out exploration there. They will also offer to Rosnieft technology transfer, staff exchange and the purchase of shares in their assets outside Russia (for example in the North Sea or in South America). Rosnefts deals with Western energy companies prove that the Russian government is resuming the policy of a controlled opening-up of the Russian energy sectors to foreign investors which it initiated in 2006. So far, investors have been given access to the Russian electric energy sector and some onshore gas fields. The agreements which have been signed so far also allow them to work on the Russian continental shelf. This process is being closely supervised by the Russian government, which has enabled the Kremlin to maintain full control of this sector. The primary goal of this policy is to attract modern technologies and capital to Russia and to gain access to foreign assets since this will help Russian corporations to reinforce their positions in international markets. The signing of the above agreements does not guarantee that production will commence. These are a high-risk projects. It remains uncertain whether crude can be extracted from those fields and whether its development will be cost-effective. According to estimates, the Russian Arctic shelf holds approximately 113 billion tonnes of hydrocarbons. The development of these fields, including building any necessary infrastructure, may consume over US$500 billion within 30 years. Furthermore, the legal regulations currently in force in Russia do not guarantee that foreign investors will have a share in the output from these fields. Without foreign support, Russian companies are unlikely to cope with such technologically complicated and extremely expensive investments. In the most optimistic scenario, the oil production in the Russian Arctic may commence in fifteen to twenty years at the earliest.