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Resposta funcional e numérica do predador Orius insidiosus (Say, 1832) (Hemiptera: Anthocoridae) com diferentes presas /Guedes, Ivone Vilar. January 2006 (has links)
Orientador: Sérgio Antonio de Bortoli / Banca: Nilza Maria Martinelli / Banca: Elisângela de Souza Loureiro / Resumo: Este trabalho teve como objetivo avaliar a capacidade predatória, aspectos comportamentais, reprodutivos e estabelecer a curva de resposta funcional do predador O. insidiosus predando ovos e lagartas de primeiro ínstar de Diatraea sacchara/is, P/utella xy/ostella, Spodoptera frugiperda e Anticarsia gemmatalis, e ninfas de terceiro/quarto ínstar de Aphis gossypii. Além destas avaliações, observou-se alguns aspectos reprodutivos de O. insidiosus, todos em função das diferentes densidades de A. gossypii. Para as espécies estudadas o predador apresentou curva de resposta funcional tipo 11, mostrando uma tendência de estabilização nas densidades mais altas. A taxa de ataque foi de 42,16; 9,35 e 22,81 ovos/hora e o tempo de manipulação de 1,56; 1,91 e 1,74 horas, para S. frugiperda, A. gemmatalis e P. xy/ostella, respectivamente. Observou-se também uma baixa capacidade predatória do O. insidiosus sobre ovos de D. saccharalis, proporcionando valores quase nulos para taxa de ataque e tempo de manipulação. A taxa de ataque foi de 15,55; 18,06; 1,77 e 3,68 lagartas/hora, e o tempo de manipulação de 2,13; 1,32; 0,86 e 1,99 horas para S. frugiperda, A. gemmatalis, D. saccharalis e P. xy/ostella, respectivamente. Para A. gossypii a taxa de ataque foi de 0,10 pulgão/hora e tempo de manipulação de 1, 82 h. O predador passou de 3,10 a 4,08 h se alimentando de seiva no nectário foliar do algodoeiro, não tendo a densidade da presa influência direta sobre esse comportamento. A proporção de postura por fêmea foi crescente até 10 ninfas, enquanto a proporção do número de ovos por postura aumentou com o aumento de presas disponíveis. / Abstract: The aim of this research was to evaluate the predatory capacity, behavior aspects and to establish O. insidiosus functional response curve preying Diatraea saccharalis, P/utella xy/ostella, Spodoptera frugiperda and Anticarsia gemmatalis eggs and first instar larvae, and Aphis gossypii third/fourth instar nymphs. By these evaluations it was observed some reproductive aspects of O. insidiosus, in function of A. gossypii different densities. The functional response type 11 was observed for ali species, showing a tendency of stability in the highest densities. The attack rate was 42.16, 9.35 e 22.81 eggs/hour and the handling time 1.56, 1.91 e 1.74 hours for S. frugiperda, A. gemmatalis and P. xy/ostella, respectively. It was also verified a low predatory capacity of O. insidiosus on D. saccharalis eggs, with almost null values for attack rate and handling time, making them despicable. The attack rate was 15.55,18.06,1.77 and 3.68Iarvae/hour, and the handling time 2.13, 1.32,0.86 e 1.99 hours for S. frugiperda, A. gemmatalis, D. saccharalis and P. xy/ostella, respectively. For A. gossypii the attack was 0.10 aphid/hour and the handling time 1.82 h. The predator teal on cotton sap and foliar nectary for 3.10 to 4.08 h, and there was no straight influence of the prey on this behavior. The egg-Iaying by female was crescent, until 10 nymphs, while the egg rate by egg-Iaying increased as the number of preys increased. / Mestre
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A ways and means analysis of sub-state political violenceBlocksome, Patricia J. January 1900 (has links)
Doctor of Philosophy / Security Studies / Sam R. Bell / This project examines the choices that rebel groups make between different types of sub-state political violence campaigns. I argue that rebels will choose a specific campaign type based on variations in the levels of state actions that cause grievances (referred to as coercion), and the capacity of both the state and the rebel group. This project develops a framework to explain the rebel decision-making process. The rebels seek to change the political behavior of the state by undertaking some form of violent campaign. Rebel campaigns are the ways in which rebels seek to obtain their ends; this project delineates between terrorist, insurgent, and civil war campaigns. However, rebels’ choice of campaign is affected by several factors: coercion, state administrative capacity, state military capacity, rebel administrative capacity, and rebel military capacity. I hypothesize that the different types of campaigns are affected differently by these factors. Additionally, I hypothesize that levels of coercion are more strongly related to the initial year of the campaign than subsequent years, regardless of campaign type. These hypotheses are analyzed via quantitative and qualitative methods. Quantitatively, this includes the development of novel latent variables for coercion and capacity prior to empirical testing of the hypotheses. Qualitatively, two case studies of rebel groups are examined; the Mau Mau in Kenya and the LTTE in Sri Lanka. The research finds limited support for the hypotheses regarding the relationships between coercion and capacity, and the rebels’ choice of campaign.
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An evaluation of empowering volunteers for capacity-building: a case study of Women for Peace, Nobantu Centre, Mfuleni, Western CapeBurrows, Michelle Isabel January 2007 (has links)
Magister Artium - MA / This thesis explored the empowerment needs of volunteer members of Women for Peace at the Nobantu Centre, Mfuleni in the Western Cape. The volunteer members, the majority of whom are women, come from a previously disadvantaged background created by the Apartheid system used in South Africa from 1948-1994. Apartheid driven education purposefully taught an inferior form of education to the black masses. This case study investigated the needs of the volunteer members, the impact that the four empowerment programmes had on the volunteer members and their future needs after being empowered. / South Africa
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The establishment of evidence based filtered information on interventions addressing the successful completion of thesis requirements in postgraduate studiesHendricks, Abeedah January 2014 (has links)
Magister Artium (Psychology) - MA(Psych) / Postgraduate students are assumed to develop the capacity to conduct research independently and to evaluate their own work as internal supervisors through the process of thesis supervision. Research capacity building amongst postgraduate students is evidenced by the successful completion of degree requirements or graduation, but student retention and throughput is a problem. The study aimed to establish an evidence base of filtered information on interventions addressing the successful completion of thesis requirements in postgraduate students. The study design entailed a systematic review that explored published findings about research reporting on capacity building strategies and initiatives respectively. The researcher made the following ethical considerations namely, transparency, non-bias during data extraction and using two independent reviewers to assist the principle researcher and avoidance of plagiarism as the proposed study is project based and a collaborative process, which are essential when using a systematic review approach. The proposed study forms part of a larger parent study, which aims to identify factors that facilitate or hinder research capacity development in postgraduate students and new academics. The present study used an adaptation of the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) statement, which is aimed at improving the reporting of systematic reviews and meta-analysis. Extracted data were subjected to a meta-synthesis, which included descriptive meta-synthesis and theory-explicative meta-synthesis. Eight articles were identified as good quality articles based on methodological rigour. The good quality research identified 1) high quality supervision, 2) faculty modelling, 3) support and 4) protected research time as effective strategies or interventions that stimulate successful completion of the thesis requirement. The use of appropriate theoretical frameworks in understanding supervision was identified as integral to effective strategies. Limitations of the study were identified and recommendations for future research were provided.
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Using average net returns and risk measures to compare irrigation management strategiesBretz, Frances January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Nathan P. Hendricks / Risk and uncertainty are inherent in agriculture especially when lack of precipitation needed for crop production is common. Precipitation in the High Plains is highly variable. To supplement precipitation, the Ogallala Aquifer, a large underground water storage reservoir, was developed for irrigation. However, as the saturated thickness of the aquifer decreases, the rate at which water can be extracted (i.e., well capacities) decreases. Limited well capacities induce risk in agricultural production because producers may not be able to irrigate sufficiently in dry years.
This study’s objective was to develop a method to assist producers in comparing alternative irrigation management strategies in the face of risk due to a limited well capacity. The objective was accomplished by simulating average net returns for 172 different irrigation strategies across 30 years (1986-2015) of historical weather (Kansas Mesonet 2016). Management strategies include different combinations of corn and wheat production with full irrigation, moderate irrigation, deficit irrigation and dryland production. The three risk measures were Value at Risk (VaR), expected shortfall, and standard deviation.
The risk-return tradeoff is estimated for management strategies for two well capacities, 300 GPM (gallons per minute) and 600 GPM. Estimating these risk measures can help producers better evaluate the optimal management strategy compared to the approach of only equating average net returns.
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Optimised small scale reative compensation for Eskom's Albany-Wesley 66/22Kv transmission systemNdimurwimo, Alexis January 2012 (has links)
Reactive power compensation, as generated by capacitors, has been used to mitigate the constraints of power transmission and improve the power transfer of the transmission system of the South African power utility, Eskom‟s 66/22kV Albany-Wesley transmission system. An investigation was carried out on a number of current compensation schemes, and their operations, by means of load flow analysis. Different capacitor qualities and technologies were applied to alter the transmission line characteristics that resulted in acceptable voltage regulation. This resulted in easing the load on the lines and transformers and hence reducing line losses. For long transmission lines, utilities need voltage support, as provided for by different voltage compensators, to keep the terminal voltage within standard voltage regulation, and meet the designed power demand. The approach to large and small scale compensation was tested and the outcomes revealed distinct patterns that were used to confirm the hypothesis and improve the transfer of power. The templating temperature and thermal perspective as used by Eskom on line design was discussed and used to design a new transmission line. Load flow solutions were also used to plan and design the optimised transmission system as well as to determine the specification and location of the compensating capacitor banks. Capacitor banks, as a source of reactive power, were used to model the compensation in this research. Electrical protection and faults associated with the capacitors banks were discussed, as prevention to total blackout or load shedding on the transmission line in case of established contingency. Long term investment plans, to meet future electricity demands, require substantial investment hence a financial survey was carried out. Finally this dissertation selects a viable solution to meet the electrical power demands and then recommends a way forward for the Eskom‟s 66/22kV Albany-Wesley line.
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A Simulation Approach for Capacity Planning in an Open Community Care NetworkZakeri Hosseinabadi, Maryam January 2017 (has links)
One of the impacts of rising demand for community health services is on long term capacity planning. Demand for community services arises directly from the community-mainly seniors- as well as from those discharged from the hospital. This thesis is focused on developing a simulation model based on patient flow in a set of community care facilities in order to help reduce the back log of patients remaining in acute care due to a lack of capacity in these facilities.
Our model will provide the user with policy recommendations that address capacity allocation in different post-acute care alternatives over a multi-year time-horizon. In the model, patients differentiated by age and gender flow through the system with stochastic lengths of stay at each node (representing a facility type). We used historical data to classify patients. Proposed factors that influence the arrival and LOS parameters such as age and gender are tested on available data. We used Excel, Minitab and ARENA Input Analyzer to estimate the distribution of LOS, the arrival pattern and the age and gender distribution of new patients. We used Arena software for the simulation. The objective is to minimize patients waiting in the system subject to a constraint on the rate of expansion of facilities. Scenarios are informed by a previous queuing network model that provides the ideal capacity plan. The proposed method seeks to provide a means of determining the potential impact of various rates of expansion and changes in demand in order to more adequately plan future development.
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Nationalization : a case from the Middle East 'Kingdom of Bahrain'Al-Aali, La'aleh Mohamed Moosa Jafar January 2014 (has links)
This research explores human resource development ‘HRD’ as a ‘nationalization strategy’ within developing contexts. A framework for managing nationalization challenges and issues is constructed based on a ‘development’ concept at a national level. The development concept researched in the study is examined and explored through HRD and capacity building. Nationalization as an HRD national strategy is of crucial importance in developing country contexts, and this is especially true for the Gulf Cooperation Council (GCC) countries in the Middle East. Nationalization strategies have been applied by GCC countries in the Middle East to increase national labour participation within the economy. Since the early 1980s, although nationalization strategies have been implemented through government authorities and ministries, the expatriate employment share remains at around 70 per cent with increasing national unemployment rates. The main aim of the research is to explore the role of nationalization programs within an HRD framework designed to build capacity from national human resources. Forces of resistance towards nationalization are addressed through a development framework that depends on human resource development and capacity building. Nationalization challenges are examined within developing contexts along with HRD theories presenting an intersection that positions ‘nationalization’ within HRD literature. Addressing nationalization issues through a ‘qualitative’ approach, distinct from quantitative measures such as quotas, proves to be a necessity for transitioning national labour towards a diversified economy in the GCC. The framework presented to address nationalization in the GCC was explored at the individual, organizational and national levels, hence presenting the nationalization challenges faced by the main executors of nationalization policies. The research findings reveal a strong correlation between the real practice of nationalization and HRD theories revealing the intersection between key concepts. The research findings demonstrate the significance of the intersection of nationalization and HRD, thus positioning nationalization within the HRD literature. The research findings reveal other ‘qualitative’ factors necessary to ensure long-term economic returns. The relevant areas include preparation of HRD professionals, coordination among entities, balancing supply and demand for labour, creating desired private sectors, education and culture. Considering retention strategies within nationalization indicates to be a crucial necessity to avoid lost investments in nationalization efforts. An examination of the role of career development in private sector organizations in Bahrain for managing and retaining local talents within nationalization initiatives reveals the importance of considering monetary rewards and creating suitable nationalized sectors that are attractive to nationals. The research examination of change management processes within nationalization in Bahrain provides strong evidence of the importance of considering qualitative approaches for developing economic sectors through national human resource interventions by embedding capacity building processes that can create long-term economic sustainable benefits within the economy. Therefore, the research findings provide a nationalization framework that takes a holistic approach by revealing findings at the individual, organizational and national levels that are essential to consider for increasing national human resources participation in developing economies such as the GCC countries where resistance towards nationalization persists.
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Toerekeningsvatbaarheid in die Suid-Afrikaanse Strafreg (Afrikaans)Nel, Pieter Willem 23 June 2008 (has links)
This study addresses the principles applicable to criminal capacity in the South African legal system. Focus is drawn to non-pathological criminal incapacity as a complete defence to a criminal charge. Non-pathological criminal incapacity can be described as the temporary inability on the part of the perpetrator to appreciate the wrongfulness of the conduct and/or to act in accordance with this appreciation. This mental inability is due to factors which cannot be ascribed to a pathological condition or mental illness. The study further investigates the application of the subjective and objective test as criteria for the defence of provocation and indicates the preferred test. The study also includes a discussion of the following aspects: • The study further investigates the application of the subjective and objective test as criteria for the defence of provocation Non-pathological criminal incapacity distinguished from pathological criminal incapacity • Non-pathological criminal incapacity distinguished from "sane" automatism • The role of amnesia in considering criminal capacity • The role of the expert witness in considering non-pathological criminal incapacity • Private defence versus battered woman syndrome and cumulative provocation • Criminal capacity and sentence. In the South African law the defence of non-pathological criminal incapacity was considered on numerous occasions by the High and Appeal Court, though mostly unsuccessful. It is also clear that the South African courts confuse the issue and fail to differentiate between the defences of non-pathological criminal incapacity and "sane" automatism. The study indicates that the two defences, though different, coincide. The South African courts increasingly raised the standard and requirements for a successful plea in an attempt to confine the popularity of the "new" defence of non-pathological criminal incapacity. A comparative study of the English and Canadian law indicates that provocation is only considered as a partial defence to murder, and only to reduce murder to manslaughter. The reasoning behind this was to evade the compulsory sentence of life imprisonment for murder by substituting it with a conviction of manslaughter where life imprisonment is not a compulsory sentence. The central question raised in this study is whether non-pathological criminal incapacity be a qualified and complete defence to any criminal charge in the South African law. Finally the study is concluded with a crisp summary of every preceding chapter and valuable recommendations stemming from the research are made. / Dissertation (LLM (Public Law))--University of Pretoria, 2008. / Public Law / unrestricted
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Is 100 Percent Debt Optimal? Three Essays on Aggressive Capital Structure and Myth of Negative Book Equity FirmsLuo, Haowen 08 1900 (has links)
This dissertation comprises of three related essays in regard of puzzling negative book equity phenomenon among U.S. public firms. In essay 1, I present the evidence that there is an increasing trend of negative book equity firms over the past 50 years, from 0.3% up to over 5% among publicly traded firms in US. In contrast to previous research which generally classify these firms as distressed firms with highly likelihood of bankruptcy, I propose a new method to separate Healthy Negative Book Equity Firms (HNBEF) from relatively more distressed negative book equity firms. The results show that HNBEF have much higher net income and interest coverage ratio, they survive longer, and pay more dividends. More interestingly, these firms are often actively increase share repurchases and debt issuance. These facts, combined with their strong profitability, indicate that managers of these firms are actively increasing their leverage and choose to be negative book equity firms.
To explain the existence of HNBEF, in essay 2, I investigate several possible reasons that may contribute to the extreme leverage of these firms. I find that HNBEF are substantially undervalued by their book assets as stated on the balance sheet. In addition, the value of intangible assets, especially those off-balance sheet intangible assets, is positively related to the probability of becoming HNBEF. Moreover, I find that characteristics of intangible assets and firms also play important role on existence of HNBEF. Specifically, I find that both liquidity and redeployability of intangible assets are positively related with the probability of becoming HNBEF. Also, firms associated with closer borrower-lender relationship are more likely to become HNBEF.
To investigate if the aggressive capital structure adopted by HNBEF is optimal, in essay 3, I performed several tests to analyze how these firms differ from other firms in terms of operating performance, corporate governance and firm value. My research finds that compared to firms from same industry and with similar size, managers of HNBEF invest more heavily in their own firms, and HNBEF have better corporate governance. In addition, HNBEF are associated with better operating performance and higher value.
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