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Kvinnors upplevelse av att leva med endometrios : En litteraturöversikt / Women's experience of living with Endometriosis : A literature reviewMartinsson, Elisabeth, Södergren, Hanna January 2018 (has links)
Endometrios förekommer hos tio procent av kvinnorna i reproduktiv ålder och karakteriseras av att livmoderslemhinnan felaktigt växer utanför livmodern. Det är vanligt att det tar lång tid att få en diagnos och det påverkar kvinnorna både emotionellt och fysiskt. Sjukdomen är kronisk och trots att det finns många olika behandlingsformer är symtomen ofta svåra att bli av med. Att leva med endometrios är en subjektiv upplevelse och det är därför viktigt att sjuksköterskan ger individanpassad och adekvat vård. Kvinnornas situation behöver beaktas för att kunna lindra deras lidande. Syftet var att belysa kvinnors upplevelse av att leva med endometrios. Metoden för studien har varit en litteraturöversikt. Skillnader och likheter jämfördes i de tio resultatartiklarna. Artiklarna har varit av både kvantitativ och kvalitativ design och inhämtades från databaserna PubMed, Cinahl Complete och Academic Search Complete. Ur resultatet framkom fyra teman. Det första temat var Kvinnors välbefinnande med två subteman; Fysik välbefinnande och Psykiskt välbefinnande. Det andra temat var Ekonomiska svårigheter med följande subteman; Sjukfrånvaro och Arbete. Det tredje temat var Förlust av femininitet med två subteman; Sexuell hälsa och Infertilitet. Det fjärde och sista temat var Socialt med kommande två subteman; Relationer till närstående och Betydelsen av stöd. Upplevelsen av att leva med endometrios var förenat med otillräcklig hjälp mot smärta. Hälso- och sjukvården har ett ansvar att ta kvinnans upplevelse på allvar och se till varje unik situation. Det styrks även av Jean Watsons “Human caring science nursing paradigm” där sjuksköterskan behöver arbeta utifrån ett helhetsperspektiv. / Endometriosis occurs in ten percent of the women in reproductive age and is characterized by the endometrium incorrectly grows outside the uterus. It normally takes a long time to get a diagnose which affects the women both emotionally and physically. The disease is chronic and although there are many different therapies the symptoms are often difficult to get rid of. Living with endometriosis is a subjective experience and it is therefore important that the nurse provides personalized and adequate care. The women's situation needs to be considered to alleviate their suffering. The aim was to illuminate the women's experience of living with Endometriosis. The method of the study has been a literature review. Differences and similarities were compared in the ten results articles. The articles have been of both quantitative and qualitative design and were collected from databases PubMed, Cinahl Complete and Academic Search Complete. Four results emerged from the result. The first theme was Women's well-being with two subtemens; Physical well-being and mental well-being. The second theme was Economic difficulties with the following subtemes; Sick leave and work. The third theme was Loss of femininity with two subtemens; Sexual Health and Infertility. The fourth and last theme was Social with upcoming two subtemens; Relationships with related parties and the importance of support. The experience of living with endometriosis was associated with insufficient help against pain. Healthcare is responsible for taking the women's experience seriously and see to every unique situation. It is also reinforced by Jean Watson's "human caring science nursing paradigm" where the nurse needs to work from an overall perspective.
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Profiling large-scale live video streaming and distributed applicationsDeng, Jie January 2018 (has links)
Today, distributed applications run at data centre and Internet scales, from intensive data analysis, such as MapReduce; to the dynamic demands of a worldwide audience, such as YouTube. The network is essential to these applications at both scales. To provide adequate support, we must understand the full requirements of the applications, which are revealed by the workloads. In this thesis, we study distributed system applications at different scales to enrich this understanding. Large-scale Internet applications have been studied for years, such as social networking service (SNS), video on demand (VoD), and content delivery networks (CDN). An emerging type of video broadcasting on the Internet featuring crowdsourced live video streaming has garnered attention allowing platforms such as Twitch to attract over 1 million concurrent users globally. To better understand Twitch, we collected real-time popularity data combined with metadata about the contents and found the broadcasters rather than the content drives its popularity. Unlike YouTube and Netflix where content can be cached, video streaming on Twitch is generated instantly and needs to be delivered to users immediately to enable real-time interaction. Thus, we performed a large-scale measurement of Twitchs content location revealing the global footprint of its infrastructure as well as discovering the dynamic stream hosting and client redirection strategies that helped Twitch serve millions of users at scale. We next consider applications that run inside the data centre. Distributed computing applications heavily rely on the network due to data transmission needs and the scheduling of resources and tasks. One successful application, called Hadoop, has been widely deployed for Big Data processing. However, little work has been devoted to understanding its network. We found the Hadoop behaviour is limited by hardware resources and processing jobs presented. Thus, after characterising the Hadoop traffic on our testbed with a set of benchmark jobs, we built a simulator to reproduce Hadoops job traffic With the simulator, users can investigate the connections between Hadoop traffic and network performance without additional hardware cost. Different network components can be added to investigate the performance, such as network topologies, queue policies, and transport layer protocols. In this thesis, we extended the knowledge of networking by investigated two widelyused applications in the data centre and at Internet scale. We (i) studied the most popular live video streaming platform Twitch as a new type of Internet-scale distributed application revealing that broadcaster factors drive the popularity of such platform, and we (ii) discovered the footprint of Twitch streaming infrastructure and the dynamic stream hosting and client redirection strategies to provide an in-depth example of video streaming delivery occurring at the Internet scale, also we (iii) investigated the traffic generated by a distributed application by characterising the traffic of Hadoop under various parameters, (iv) with such knowledge, we built a simulation tool so users can efficiently investigate the performance of different network components under distributed application.
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Bandwidth-efficient video streaming with network coding on peer-to-peer networksHuang, Shenglan January 2017 (has links)
Over the last decade, live video streaming applications have gained great popularity among users but put great pressure on video servers and the Internet. In order to satisfy the growing demands for live video streaming, Peer-to-Peer(P2P) has been developed to relieve the video servers of bandwidth bottlenecks and computational load. Furthermore, Network Coding (NC) has been proposed and proved as a significant breakthrough in information theory and coding theory. According to previous research, NC not only brings substantial improvements regarding throughput and delay in data transmission, but also provides innovative solutions for multiple issues related to resource allocation, such as the coupon-collection problem, allocation and scheduling procedure. However, the complex NC-driven P2P streaming network poses substantial challenges to the packet scheduling algorithm. This thesis focuses on the packet scheduling algorithm for video multicast in NC-driven P2P streaming network. It determines how upload bandwidth resources of peer nodes are allocated in different transmission scenarios to achieve a better Quality of Service(QoS). First, an optimized rate allocation algorithm is proposed for scalable video transmission (SVT) in the NC-based lossy streaming network. This algorithm is developed to achieve the tradeoffs between average video distortion and average bandwidth redundancy in each generation. It determines how senders allocate their upload bandwidth to different classes in scalable data so that the sum of the distortion and the weighted redundancy ratio can be minimized. Second, in the NC-based non-scalable video transmission system, the bandwidth ineffi- ciency which is caused by the asynchronization communication among peers is reduced. First, a scalable compensation model and an adaptive push algorithm are proposed to reduce the unrecoverable transmission caused by network loss and insufficient bandwidth resources. Then a centralized packet scheduling algorithm is proposed to reduce the unin- formative transmission caused by the asynchronized communication among sender nodes. Subsequently, we further propose a distributed packet scheduling algorithm, which adds a critical scalability property to the packet scheduling model. Third, the bandwidth resource scheduling for SVT is further studied. A novel multiple- generation scheduling algorithm is proposed to determine the quality classes that the receiver node can subscribe to so that the overall perceived video quality can be maxi- mized. A single generation scheduling algorithm for SVT is also proposed to provide a faster and easier solution to the video quality maximization function. Thorough theoretical analysis is conducted in the development of all proposed algorithms, and their performance is evaluated via comprehensive simulations. We have demon- strated, by adjusting the conventional transmission model and involving new packet scheduling models, the overall QoS and bandwidth efficiency are dramatically improved. In non-scalable video streaming system, the maximum video quality gain can be around 5dB compared with the random push method, and the overall uninformative transmiss- sion ratio are reduced to 1% - 2%. In scalable video streaming system, the maximum video quality gain can be around 7dB, and the overall uninformative transmission ratio are reduced to 2% - 3%.
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Low latency audio processingWang, Yonghao January 2018 (has links)
Latency in the live audio processing chain has become a concern for audio engineers and system designers because significant delays can be perceived and may affect synchronisation of signals, limit interactivity, degrade sound quality and cause acoustic feedback. In recent years, latency problems have become more severe since audio processing has become digitised, high-resolution ADCs and DACs are used, complex processing is performed, and data communication networks are used for audio signal transmission in conjunction with other traffic types. In many live audio applications, latency thresholds are bounded by human perceptions. The applications such as music ensembles and live monitoring require low delay and predictable latency. Current digital audio systems either have difficulties to achieve or have to trade-off latency with other important audio processing functionalities. This thesis investigated the fundamental causes of the latency in a modern digital audio processing system: group delay, buffering delay, and physical propagation delay and their associated system components. By studying the time-critical path of a general audio system, we focus on three main functional blocks that have the significant impact on overall latency; the high-resolution digital filters in sigma-delta based ADC/DAC, the operating system to process low latency audio streams, and the audio networking to transmit audio with flexibility and convergence. In this work, we formed new theory and methods to reduce latency and accurately predict latency for group delay. We proposed new scheduling algorithms for the operating system that is suitable for low latency audio processing. We designed a new system architecture and new protocols to produce deterministic networking components that can contribute the overall timing assurance and predictability of live audio processing. The results are validated by simulations and experimental tests. Also, this bottom-up approach is aligned with the methodology that could solve the timing problem of general cyber-physical systems that require the integration of communication, software and human interactions.
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Uso de cercas-vivas por aves em uma paisagem fragmentada de mata atlântica semidecídua /Gabriel, Vagner de Araújo. January 2005 (has links)
Orientador: Marco Aurélio Pizo Ferreira / Banca: Marcos Rodrigues / Banca: Reginaldo José Donatelli / Resumo: Esta pesquisa investigou o uso de cercas-vivas por aves em uma paisagem fragmentada de Mata Atlântica semidecídua em Itatiba, São Paulo. Objetivou-se (1) determinar quais espécies de aves utilizam as cercas-vivas, (2) que atividades aí realizam, (3) verificar a disponibilidade de frutos e artrópodes nas cercas-vivas, (4) se a presença das aves nas cercas-vivas está relacionada à disponibilidade desses recursos alimentares e (5) caracterizar a estrutura da vegetação das cercas-vivas e compará-las aos fragmentos estudados. Foram estudados cinco fragmentos e três cercas-vivas, que conectam tais fragmentos. Nove redes de neblina foram instaladas nas cercas-vivas e 15 nos fragmentos para a captura e anilhamento de aves. Pela recaptura das aves foi inferida a função das cercas-vivas como corredor. Taxas de captura nas cercas-vivas e fragmentos foram comparadas. Para isso foram consideradas, separadamente, guildas de aves frugívoras, insetívoras, granívoras-frugívoras, granívoras-insetívoras e nectarívorasinsetívoras. Quanto às taxas de captura, excetuando-se a taxa de captura de aves insetívoras, houve diferença significativa entre cercas-vivas e fragmentos, sendo sempre maiores nas cercas-vivas. Não houve diferença na oferta de frutos e artrópodes entre cercas-vivas e fragmentos. As taxas de captura de aves frugívoras e insetívoras não estiveram relacionadas à disponibilidade de frutos e artrópodes. Cercas-vivas e fragmentos pouco diferiram quanto à estrutura da vegetação. Concluiu-se que a presença de cercas-vivas pode amenizar os efeitos do isolamento a que estão sujeitas muitas aves tropicais devido à fragmentação de seu habitat / Abstract: This study investigated the use of live fences by birds in a fragmented Atlantic forest landscape in Itatiba, SE Brazil. The purpose of it was (1) identify what bird species use the live fences, (2) record what they do in the live fences, (3) investigate the availability of food resources (fruit and arthropod) in live fences, (4) investigate if the food availability influences the use of live fences by birds and (5) characterize the vegetation structure of live fences and forest fragments. Five forest fragments and three live fences that connect such fragments were studied. Nine mist-nets were installed in live fences and 15 in forest fragments to capture and band birds. For this, captured birds were classified into the following foraging guilds: frugivores, insectivores, granivores-frugivores, granivoresinsectivores and nectarivores-insectivores. Except for insectivorous birds, significant differences in capture rates between live fences and forest fragments were detected. Capture rates in live fences were always greater than in fragments. There was no difference in the availability of food resources between live fences and fragments. The capture rates of frugivorous and insectivorous birds were not related to the availability of fruits and arthropods. The vegetation structure at live fences and forest fragments differed little from each other. I concluded that live fences can serve as movement corridors for birds at the study site, thus helping to reduce the usually deleterious effects of isolation caused forest fragmentation / Mestre
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Recording and amplifying of the accordion : What is the best way to capture the sound of the acoustic accordion?Řehák, Milan January 2019 (has links)
In this thesis I discuss, analyse and intend to answer the question: What is the best way to capture the sound of the acoustic accordion? It was my desire to explore this theme that led me to this research, and I believe that this question is important to many other accordionists as well. From the very beginning, I wanted the thesis to be not only an academic material but also that it can be used as an instruction manual, which could serve accordionists and others who are interested in this subject, to delve deeper into it, understand it and hopefully get answers to their questions about this subject. The thesis contains five main chapters: Amplifying of the accordion at live events, Processing of the accordion sound, Recording of the accordion in a studio - the specifics of recording of the accordion, Specific recording solutions and Examples of recording and amplifying of the accordion in practice of other accordion players, and two recordings: D. Scarlatti - Sonata D minor K 141, V. Trojan - The Collasped Cathedral. My aim is that this thesis will contribute to create a comprehensive insight into the specifics of capturing the accordion sound, contribute to better understanding of the acoustic properties of the instrument and bring practical answers to questions that many accordionists have. I have chosen to mention very basic technical aspects related to how to capture the sound of the acoustic accordion with respect to potential elementary knowledge of some people in this area. But, I also discuss very specific and professional details and focus on how different kinds of microphones can be used to capture the sound of the acoustic accordion. This is a subject that clearly is understudied and probably not has been a matter for proper research before. Most of my comments and analysis come from my personal experience and different experiments but there is also an interview included in the thesis with one very experienced accordionist who also is a professional music producer. I hope that my thesis will help other accordionists, sound engineers, and anyone else to understand the accordion and its specifics regarding both studio recording and live amplifying.
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Design and implementation of transgenic tools to visualise cell cycle progression in mammalian developmentFord, Matthew Jonathan January 2017 (has links)
Cell cycle progression is the series of steps a cell has to take in order to duplicate its DNA and produce two daughter cells. Correct spatial and temporal coordination of the cell cycle is key for the normal development of any organ or tissue and is stringently controlled during embryogenesis and homeostasis. Misregulation of cell cycle progression is causal in many developmental disorders and diseases such as microcephaly and cancer. Fucci (Fluorescent Ubiquitination based Cell Cycle Indicator) is a system that allows for the visualisation of cell cycle progression by the use of two differently coloured fluorescent probes whose abundance is regulated reciprocally during the cell cycle. The probes contain the E3 ligase recognition domains of Cdt1 and Geminin fused to the fluorophores mCherry (red fluorescence) and mVenus (yellow fluorescence) respectively. Cells are therefore labelled red during G1, yellow in the G1/S transition and green during late S/G2 and M phases of the cell cycle. In order to study development and tissue homoeostasis a Fucci expressing mouse line was developed however this has several key limitations: First, the two Fucci probes are expressed from separate loci complicating mouse colony maintenance. Second, the constructs were not inducible, making it impossible to follow cell cycle progression in specific cell lineages and third the mice were generated by random transgenesis which is prone to silencing and can exhibit variation in expression between different tissues. Here I have characterised an improved version of the original Fucci system known as Fucci2a designed by Dr Richard Mort (University of Edinburgh) to overcome these limitations. The Fucci2a genetic construct contains both Fucci probes fused with the Thosea asigna virus self-cleaving peptide sequence T2A. This allows expression of both probes as a single bicistronic mRNA with subsequent cleavage by ribosomal ‘skipping’ during translation to yield separate proteins. A Fucci2a mouse (R26Fucc2aR) was generated by homologous recombination into the ROSA26 locus using the strong, ubiquitous CAG promoter to drive expression and incorporating a floxed-Neo stop cassette. This allows tissue specific activation by Cre recombinase when combined with a second Cre expressing mouse line. Building on the bicistronic Fucci2a technology I have gone on to develop and characterise four new tricistronic reporter constructs which allow for the dual visualisation of cell cycle progression with apoptosis, cytokinesis and ciliogenesis. In each case an additional fluorescent probe was added to the original Fucci2a construct separated by the self-cleaving peptide P2A and the construct characterised in 3T3 stable cell lines. The combination of a dual cilia and cell cycle reporter construct proved fruitful and I have gone on to investigate the relationship between cell cycle progression and ciliogenesis in 3T3 cells and have generated and characterised the R26Arl13b-Fucci2aR mouse line. I have also illustrated the utility of the R26Fucci2aR mouse for generating quantitative data in development research in two development situations; melanocyte development and lung branching morphogenesis. Melanocytes are specialised melanin producing cells responsible for the pigmentation of the hair, skin and eyes. Their precursors, melanoblasts, are derived from the neural crest where they migrate and proliferate before becoming localised to hair follicles and their study provides a good model for understanding the development of other neural crest derived lineages such as the peripheral nervous system. Using time-lapse imaging of ex vivo skin cultures in which melanoblasts are labelled with the Fucci probes I have characterised melanoblast migration and proliferation. In addition, I have shown that Kit signalling, which is necessary for melanoblast migration and survival, controls melanoblast proliferation in a density dependent manner and that melanoblast migration is more persistent in S/G2/M phases of the cell cycle. Lung branching morphogenesis requires constant proliferation at the apical tip of a growing epithelial branch. Loss of epithelial symmetry through an unidentified mechanism (requiring BMP, FgF10, Shh and Wnt signalling) within a branch is required to initiate branching either latterly from the side of a elongating branch by domain branching or by bifurcation of the tip. In the final section of this thesis I performed a comparative analysis of the behaviour of the developing lung epithelium using proliferative status (Fucci2a expression) to categorise each cell. Using a combination of live imaging and immunohistochemistry I have identified a transition zone 100-150μm from the tip of the branching lung epithelium where epithelial cells become stationary and drop out of the cell cycle corresponding with the onset of proximal bronchial progenitor marker Sox2. A comparative gene expression analysis of the proliferating and non-proliferating regions using Fucci2a to distinguish them has eluded to several interesting genes which could influence branching morphogenesis during lung development.
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Kvalita života pacienta po systémové trombolýze / Patient Quality of Live after Systematic ThrombolysisMatúšová, Veronika January 2012 (has links)
Diploma thesis "Quality of life of patients after systemic thrombolysis" is dealing with the impact of systemic thrombolysis to the quality of life of patients affected by the ischemic stroke (IS) and treated with intravenous administration of thrombolytics. The goal is to objectively assess quality of life resulting from health improvement after systemic thrombolysis. The work consists of theoretical and practical part. The theoretical part describes ischemic stroke, its etiology, symptoms and treatment options. The second chapter is devoted to the practical part of the term "quality of life", methods that are used to measure quality of life. This chapter also deals with the consequences of IS for patient's life. In the practical part we focused on monitoring the physical and mental health in patients with IS, who were treated with intravenous systemic thrombolysis, and in patients who have not undergone this treatment. Each study group of patients had 18 patients. The results of both groups we evaluated and compared. In the survey we used a retrospective analysis of medical data and a survey using the questionnaire SF-36 on the health-related quality of life. The survey results confirmed the assumption that patients treated with thrombolysis have less neurological deficit and thus better physical...
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Fontes e níveis de proteína na alimentação do lambari-do-rabo-amarelo: desempenho prdutivo e análise econômica / Sources and protein levels in the diet of lambari-do-rabo-amarelo: productive performance and economic analysisSussel, Fábio Rosa 23 November 2012 (has links)
Este trabalho teve como por objetivo desenvolver dietas nutricionalmente adequadas e financeiramente viáveis para o lambari, além de analisar economicamente a viabilidade de produção desta espécie no sistema de tanques-rede como alternativa de renda ao pescador artesanal. Previamente, foram realizados dois ensaios, os quais tiveram por finalidade determinar a densidade de estocagem adequada para lambaris em tanques-rede, bem como ajustar o manejo experimental (sistema de contagem e povoamento, tempo de exposição a anestésicos, dinâmica das biometrias, etc.). Os experimentos foram realizados no verão, entre os meses de janeiro e abril , na UPD de Pirassununga - APTA Polo Centro Leste, em 20 tanques-rede de 1 m3 alocados em tanque escavado de 1,5 m de profundidade, área de 180 m2, renovação de água de 10% ao dia e densidade de povoamento de 450 peixes/m3. No primeiro experimento, que teve início em 16/02/2011 e duração de 63 dias, avaliou-se a substituição da proteína de origem animal por proteína de origem vegetal nas dietas sobre o desempenho produtivo dos lambaris. Embora a substituição de 100% das fontes proteicas de origem animal por vegetal tenha afetado negativamente o ganho em biomassa [Biomassa (g) = 2945g - 2,2 POV], em termos práticos, este resultado é considerado de pouca relevância, já que 220g em 2945g não representam mais que 7% de ganho em peso. O aumento do custo de fórmula em dietas com base proteica de origem animal não justifica a diferença observada. Quanto à composição corporal dos peixes observou-se que houve influência dos tratamentos, sendo que dietas contendo inclusões de 50, 75 e 100% de ingredientes proteicos de origem vegetal proporcionaram maior deposição de extrato etéreo nos peixes. No segundo experimento, com início em 12/01/2012 e término em 12/03/2012, avaliou-se a relação entre níveis de proteína bruta (26 e 36%) e qualidade de ingredientes (basal ou premium) na alimentação e desempenho produtivo do lambari. Não foram observadas diferenças de desempenho produtivo entre os níveis proteicos utilizados, sugerindo que níveis de 26% de proteína bruta podem ser usados para o lambari; no entanto, a escolha de matérias-primas de qualidade é recomendada, já que estas influenciaram no desempenho. Os tratamentos deste experimento não influenciaram na composição corporal dos peixes. As análises bromatológicas de ambas as rações experimentais apresentaram valores condizentes com os propostos na formulação e, portanto, não interferindo no propósito da pesquisa. Complementando os estudos e utilizando os resultados de desempenho produtivo obtidos, realizou-se análise econômica a partir das dietas utilizadas no segundo experimento através do sistema de Partial Budget Analysis in Aquaculture, bem como a projeção de cultivo do lambari em módulos de um a quatro tanques-rede, seguida de análise da viabilidade econômica sob dois cenários de comercialização: R$ 0,30 e 0,20 por unidade. Observou-se que o melhor custo/benefício foi proporcionado pelos peixes alimentados com ração contendo 26% de PB e ingredientes premium, enquanto que a produção de lambaris no sistema de tanques-rede mostrou-se viável, quando comparado com as receitas obtidas por pescadores artesanais, a partir do cultivo em duas unidades de produção (TR), desde que sejam comercializados ao valor de R$ 0,30 por peixe. / This study aimed to develop nutritionally appropriate and financially viable diets for lambari, besides analyze economically the practicability of producing this species in cage system as an alternative f or subsistence fishermen. Previously, two experiments were done, which had the purpose of determin ing the appropriated stocking density for lambaris in cages, as well as adjusting the experimental management (counting and settlement systems, time of exposure to anesthetics, dynamics of biometrics, etc.). The experiments were done on summer, from January to April, in Pirassununga UPD - APTA Polo Centro Leste, in 20 cages of 1m3 allocated in a pond of 180m2, water renovation of 10% a day, and stocking density of 450 fish/m3. The first experiment, which started at 02/16/2011 and lasted 63 days, was about the replacement of animal origin protein by vegetal origin protein in order to evaluate productive performance of lambaris. Although the 100% substitution of protein source from animal by vegetal origin protein had negatively affected the gain in biomass [Biomass (g) = 2945g - 2,2 POV], in practical terms, this result is considered of low relevance, since 220g in 2945g doesn\'t represent more than 7% of weight gain. The increase of cost in diets with animal protein source doesn\'t justify the difference observed. Substitution of more than 50% of POA by POV on diet increased fat deposition on the fish carcass. On the second experiment, which began at 01/12/2011 and was finished at 03/12/2012, it was evaluated the relation between levels of crude protein (26 and 36%) and quality of ingredients (basal or premium) on feeding and productive performance of lambari. Differences of productive performance weren\'t noticed, suggesting that levels of 26% crude protein can be used for lambari, however, the choice of quality raw materials is recommended since it influenced the performance. The treatments in this experiment did not influence body composition of fish. Bromatological analysis of both experimental diets had values consistent with those proposed in the formulation and, therefore, didn\'t interfere on the purpose of this research. Finally, complementing the studies and using the results of productive performance obtained, it was performed an economic analysis was performed from the diets used on the second experiment using the model Partial Budget Analysis in Aquaculture, as well as the projection of lambari cultivation in modules from 1 to 4 cages, followed by an analysis of economic viability in two scenes of commercialization: R$ 0,30 and 0,20 per unit. It was observed that the best cost/benefit was provided by fish fed with diet of 26% crude protein and premium ingredients, whereas the production of lambaris in cage system was viable when compared to incomings obtained by subsistence fishermen, since they are cultivated, at least, in 2 modules of production, and the fish are commercialized for R$ 0,30/unit.
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Stochastic Tests on Live Cattle Steer Basis Composite ForecastsDennis, Elliott James 01 May 2014 (has links)
Since the seminal papers of Bates and Granger in 1969, a superfluous amount of information has been published on combining singular forecasts. Materialized evidence has habitually demonstrated that combining the forecasts will produce the best model. Moreover, while it is possible that a best singular model could outperform a composite model, using multiple models provides the advantage of risk diversification. It has also been shown to produce a lower forecasting error. The question to whether to combine has been replaced with what amount of emphasis should be placed on each forecast.
Researchers are aspired to derive optimal weights that would produce the lowest forecasting errors. An equal composite of the mean square error, by the covariance, and the best previous model, among others, have been suggested. Other academicians have suggested the use of mechanical derived weights through the use of computer programs. These weights have shown robust results.
Once the composite and singular forecasts have been estimated, a systematic approach to evaluate the singular forecasts is needed. Forecasting errors, such as the root mean square error and mean absolute percentage error, are the most common criteria for elimination in both agriculture and other sectors. Although a valid mean of selection, different forecasting errors can produce a different ordinal ranking of the forecasts; thus, producing inconclusive results. These findings have promoted the inspection for other suitable candidates for forecast evaluation. At the forefront of this pursuit is stochastic dominance and stochastic efficiency.
Stochastic dominance and stochastic efficiency have traditionally been used as a way to rank wealth or returns from a group of alternatives. They have been principally used in the finance and money sector as a way to evaluate investment strategies. Holt and Brandt in 1985 proposed using stochastic dominance to select between different hedging strategies. Their results suggest that stochastic dominance has the opportunity to feasibly be used in selecting the most accurate forecast.
This thesis had three objectives: 1) To determine whether live cattle basis forecasting error could be reduced in comparison to singular models when using composite forecasts 2) To determine whether stochastic dominance and stochastic efficiency could be used to systematically select the most accurate forecasts 3) To determine whether currently reported forecasting error measures might lead to inaccurate conclusions in which forecast was correct. The objectives were evaluated using two primary markets, Utah and Western Kansas, and two secondary markets, Texas and Nebraska. The data for live cattle slaughter steer basis was taken and subsequently computed from the Livestock Marketing Information Center, Chicago Mercantile Exchange, and United States Department of Agriculture from 2004 to 2012.
Seven singular were initially used and adapted from the current academic literature. After the models were evaluated using forecasting error, stochastic dominance and stochastic efficiency, seven composite models were created. For each separate composite model, a different weighting scheme was applied. The “optimal” composite weight, in particular, was estimated using GAMS whose objective function was to select the forecast combination that would reduce the variance-covariance between the singular forecasting models. The composite models were likewise systematically evaluated using forecasting error, stochastic dominance and stochastic efficiency.
The results indicate that forecasting error can be reduced in all four markets, on the average by using an optimal weighting scheme. Optimal weighting schemes can also outperform the benchmark equal weights. Moreover, a combination of fast reaction time series and market condition, supply and demand, forecasts provide the better model. Stochastic dominance and stochastic efficiency provided confirmatory results and selected the efficient set of the forecasts over a range of risk. It likewise indicated that forecasting error may provide a point estimate rather than a range of error. Suggestions for their application and implementation into extension outlook forecasts and industry application are suggested.
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