898 resultados para Limits matter
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Many efforts are undertaken for sustaining urban agriculture in African cities. This study therefore investigated nutrient management practices in urban vegetable gardens of Bobo Dioulasso, Burkina Faso (West Africa). Nitrogen (N), phosphorus (P), potassium (K), and carbon (C) fluxes were quantified and nutrient balances calculated for three gardens representing the typical commercial gardening + field crops and livestock system (cGCL) and three gardens representing the commercial gardening + semi-commercial field crop system (cGscC). Nutrient and C balances were similarly positive in both production systems reaching annual averages of 688 kg N ha -1, 251 kg P ha-1 yr-1, 189 kg K ha-1, and 31 t C ha-1. Inputs in all gardens exceeded the amounts recommended by the extension service. Gaseous emissions of N and C represented important pathways of N and C losses. The highest emission rates occurred during the hottest periods of the day and the peaks were observed after fertilizer applications. Management recommendations should be geared towards increasing nutrient use efficiencies by better tailoring nutrient availability to crop demand and adjusted fertilization techniques to mitigate N losses.
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An improved understanding of soil organic carbon (Corg) dynamics in interaction with the mechanisms of soil structure formation is important in terms of sustainable agriculture and reduction of environmental costs of agricultural ecosystems. However, information on physical and chemical processes influencing formation and stabilization of water stable aggregates in association with Corg sequestration is scarce. Long term soil experiments are important in evaluating open questions about management induced effects on soil Corg dynamics in interaction with soil structure formation. The objectives of the present thesis were: (i) to determine the long term impacts of different tillage treatments on the interaction between macro aggregation (>250 µm) and light fraction (LF) distribution and on C sequestration in plots differing in soil texture and climatic conditions. (ii) to determine the impact of different tillage treatments on temporal changes in the size distribution of water stable aggregates and on macro aggregate turnover. (iii) to evaluate the macro aggregate rebuilding in soils with varying initial Corg contents, organic matter (OM) amendments and clay contents in a short term incubation experiment. Soil samples were taken in 0-5 cm, 5-25 cm and 25-40 cm depth from up to four commercially used fields located in arable loess regions of eastern and southern Germany after 18-25 years of different tillage treatments with almost identical experimental setups per site. At each site, one large field with spatially homogenous soil properties was divided into three plots. One of the following three tillage treatments was carried in each plot: (i) Conventional tillage (CT) with annual mouldboard ploughing to 25-30 cm (ii) mulch tillage (MT) with a cultivator or disc harrow 10-15 cm deep, and (iii) no tillage (NT) with direct drilling. The crop rotation at each site consisted of sugar beet (Beta vulgaris L.) - winter wheat (Triticum aestivum L.) - winter wheat. Crop residues were left on the field and crop management was carried out following the regional standards of agricultural practice. To investigate the above mentioned research objectives, three experiments were conducted: Experiment (i) was performed with soils sampled from four sites in April 2010 (wheat stand). Experiment (ii) was conducted with soils sampled from three sites in April 2010, September 2011 (after harvest or sugar beet stand), November 2011 (after tillage) and April 2012 (bare soil or wheat stand). An incubation study (experiment (iii)) was performed with soil sampled from one site in April 2010. Based on the aforementioned research objectives and experiments the main findings were: (i) Consistent results were found between the four long term tillage fields, varying in texture and climatic conditions. Correlation analysis of the yields of macro aggregate against the yields of free LF ( ≤1.8 g cm-3) and occluded LF, respectively, suggested that the effective litter translocation in higher soil depths and higher litter input under CT and MT compensated in the long term the higher physical impact by tillage equipment than under NT. The Corg stocks (kg Corg m−2) in 522 kg soil, based on the equivalent soil mass approach (CT: 0–40 cm, MT: 0–38 cm, NT: 0–36 cm) increased in the order CT (5.2) = NT (5.2) < MT (5.7). Significantly (p ≤ 0.05) highest Corg stocks under MT were probably a result of high crop yields in combination with reduced physical tillage impact and effective litter incorporation, resulting in a Corg sequestration rate of 31 g C-2 m-2 yr-1. (ii) Significantly higher yields of macro aggregates (g kg-2 soil) under NT (732-777) and MT (680-726) than under CT (542-631) were generally restricted to the 0-5 cm sampling depth for all sampling dates. Temporal changes on aggregate size distribution were only small and no tillage induced net effect was detectable. Thus, we assume that the physical impact by tillage equipment was only small or the impact was compensated by a higher soil mixing and effective litter translocation into higher soil depths under CT, which probably resulted in a high re aggregation. (iii) The short term incubation study showed that macro aggregate yields (g kg-2 soil) were higher after 28 days in soils receiving OM (121.4-363.0) than in the control soils (22.0-52.0), accompanied by higher contents of microbial biomass carbon and ergosterol. Highest soil respiration rates after OM amendments within the first three days of incubation indicated that macro aggregate formation is a fast process. Most of the rebuilt macro aggregates were formed within the first seven days of incubation (42-75%). Nevertheless, it was ongoing throughout the entire 28 days of incubation, which was indicated by higher soil respiration rates at the end of the incubation period in OM amended soils than in the control soils. At the same time, decreasing carbon contents within macro aggregates over time indicated that newly occluded OM within the rebuilt macro aggregates served as Corg source for microbial biomass. The different clay contents played only minor role in macro aggregate formation under the particular conditions of the incubation study. Overall, no net changes on macro aggregation were identified in the short term. Furthermore, no indications for an effective Corg sequestration on the long term under NT in comparison to CT were found. The interaction of soil disturbance, litter distribution and the fast re aggregation suggested that a distinct steady state per tillage treatment in terms of soil aggregation was established. However, continuous application of MT with a combination of reduced physical tillage impact and effective litter incorporation may offer some potential in improving the soil structure and may therefore prevent incorporated LF from rapid decomposition and result in a higher C sequestration on the long term.
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Two experiments were conducted to evaluate cassava root peel (CRP) as diet component for fattening pigs. In the first experiment, ten male pigs were used to investigate the nutrient digestibility and the nutritive value of CRP as replacement for maize in the diet at 0 %, 30 %, 40 %, 50 % and 60 %, while supplementing free amino acids (fAA). During two experimental periods, faeces were quantitatively collected and analysed for chemical composition. In the second experiment, 40 pigs received the same diets as in Experiment 1, and daily feed intake and weekly weight changes were recorded. Four pigs per diet were slaughtered at 70 kg body weight to evaluate carcass traits. Digestibility of dry and organic matter, crude protein, acid detergent fibre and gross energy were depressed (p<0.05) at 60 % CRP; digestible energy content (MJ kg^(−1) DM) was 15.4 at 0 % CRP and 12.7 at 60 % CRP. In the second experiment, CRP inclusion had only a small impact on feed intake, weight gain and feed conversion ratio (p>0.05) as well as on the length of the small intestine and the Longissimus dorsi muscle area. The missing correlation of daily weight gain and feed-to-gain ratio up to a CRP inclusion of 40 % indicates that negative effects of CRP on pig growth can be avoided by respecting upper feeding limits. Hence, a combined use of CRP and fAA can reduce feeding costs for small-scale pig farmers in countries where this crop-by product is available in large amounts.
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The right to food has become a pillar of international humanitarian and human rights law. The increasing number of food-related emergencies and the evolution of the international order brought the more precise notion of food security and made a potential right to receive food aid emerge. Despite this apparent centrality, recent statistics show that a life free from hunger is for many people all over the world still a utopian idea. The paper will explore nature and content of the right to food, food security and food aid under international law in order to understand the reasons behind the substantial failure of this right-centred approach, emphasising the lack of legal effects of many food-related provisions because of excessive moral connotations of the right to be free from hunger. Bearing in mind the three-dimensional nature of food security, the paper will also suggest that all attention has been focused on the availability of food, while real difficulties arise in terms of accessibility and adequacy. Emergency situations provide an excellent example of this unbalance, as the emerging right to receive food aid focus itself on the availability of food, without improving local production and adequacy. Looking at other evolving sectors of international law, such as the protection of the environment, and particularly the safeguard of biological diversity, alternative solutions will be envisaged in order to “feed” the right to food.
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This study uses data from a sample survey of 200 households drawn from a mountainous commune in Vietnam’s North Central Coast region to measure and explain relative poverty. Principal components analysis is used to construct a multidimensional index of poverty outcomes from variables measuring household income and the value of domestic assets. This index of poverty is then regressed on likely causes of poverty including different forms of resource endowment and social exclusion defined by gender and ethnicity. The ordinary least squares estimates indicate that poverty is indeed influenced by ethnicity, partly through its interaction with social capital. However, poverty is most strongly affected by differences in human and social capital. Differences in the amount of livestock and high quality farmland owned also matter. Thai households are poorer than their Kinh counterparts even when endowed with the same levels of human, social, physical and natural capital considered in the study. This empirical result provides a rationale for further research on the causal relationship between ethnicity and poverty outcomes.
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The University provides a template for the whole of a thesis but if you wish to construct a thesis by using separate files you can use this file for the introductory section. This file contains all of the sections required (Title Page, Abstract, Table of Contents etc). It also has mirror margins for double sided printing and has different odd and even page headers. Support materials for using the template are referenced near the start of the file. You will want to use this in conjunction with the Chapter http://www.edshare.soton.ac.uk/9403/ and End Matter templates http://www.edshare.soton.ac.uk/11998/
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The new Physics dept Quantum Light and Matter group logo designed by Alexey Kavokin in vector format. Re-traced original bitmap logo for high quality printing. Created in inkscape and exported to PDF, EPS and high resolution PNG
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Front matter template for Word 97/2000/2003 PC) or Word 2004 (Mac) for the University of Southampton
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In trademark systems such as the Andean Community, a state authority verifiesthat the marks are distinctive, lawful and do not affect third parties, and after that,given their ownership. In this context, particular interest has sparked the possibilityof individuals by agreements or statements of co-existence, are who ensure that theirsigns meet the conditions for simultaneous registrations.Such agreements for the coexistence of marks are problematic if one thinks thatthe holders of interests that would be available also seem to matter to consumers,competitors and the market. Therefore, define the scope of contractual freedom inthe field of trademark law, whose rules are considered imperative, acquire practicaland theoretical importance because its realization i) recognizes the risks that maybe relevant to evaluating trade agreements and ii) contributes to debates on the roleof private autonomy in areas reserved for non-derogable norms. Thus, this researchputs the declarations of consent for the coexistence of registrations in Colombia, ina larger scope of the limits of freedom of contract.
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In Metropolitan Area of Mexico City, most of urban displacements happen through semi formal public transportation: small and medium capacity vehicles operated by small private enterprises, through a concession scheme. This kind of public transportation has been playing a major role in the Mexican capital. On one hand, it has been one of the conditions for urbanization to be possible. On the other hand, despite its uncountable deficiencies, public transportation has allowed for a long time the whole population to be able to move within this huge metropolis. However, that important function with regards to integration has now reached its limits in the most recent suburbs of the city, where a new mode of urbanization is taking place, based on massive production of very big social housing gated settlements. Public transportation tends to constitute here a factor of exclusion and households meet with important difficulties for their daily mobility.
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Este trabajo recopila literatura académica relevante sobre estrategias de entrada y metodologías para la toma de decisión sobre la contratación de servicios de Outsourcing para el caso de empresas que planean expandirse hacia mercados extranjeros. La manera en que una empresa planifica su entrada a un mercado extranjero, y realiza la consideración y evaluación de información relevante y el diseño de la estrategia, determina el éxito o no de la misma. De otro lado, las metodologías consideradas se concentran en el nivel estratégico de la pirámide organizacional. Se parte de métodos simples para llegar a aquellos basados en la Teoría de Decisión Multicriterio, tanto individuales como híbridos. Finalmente, se presenta la Dinámica de Sistemas como herramienta valiosa en el proceso, por cuanto puede combinarse con métodos multicriterio.
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La exposición a polvo de cemento y sílice ha sido estudiada por años en países como Estados Unidos y Canadá, cuando el polvo de cemento se inhala durante diferentes actividades, se puede ocasionar afectación del tracto respiratorio de las personas expuestas. El estudio “Perfil de exposición ocupacional a polvo de cemento y sílice cristalina en procesos de cementación y Fracturamiento hidráulico en el sector Oil & Gas en Colombia: un estudio retrospectivo (2009 – 2013).” Permitió identificar las actividades funcionales que representan un riesgo potencial por la presencia de partículas aerosuspendidas, analizar una base de datos que reúne cerca de 18298 registros de evaluaciones higiénicas en el sector Oil & Gas, realizar posteriormente el cálculo de material particulado en la fracción respirable y sílice cristalina aplicables para cada proceso y el procesamiento de los datos estadísticamente, confrontar estos estimadores estadísticos con los valores límites permisibles definidos por el gobierno nacional, los resultados incluyeron la caracterización de un perfil de exposición ocupacional por actividad funcional para el proceso de cementación, la identificación de los trabajadores más expuestos según las condiciones de exposición y cuáles de estos perfiles superan los límites máximos permisibles para un turno de trabajo de 12 horas, esta información permitirá a los profesionales de la salud e higiene laboral orientar actividades de seguimiento, vigilancia y control en los grupos de exposición similar específicos. Para el proceso de fracturamiento hidráulico los datos encontrados no fueron estadísticamente significativos.