Thesis (Ph.D.) in Zoology--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 95-108).

The main parasite affecting the Scottish Atlantic salmon farming industry is Lepeophtheirus salmonis costing approximately £29 million annually through lost production and treatments. As such, the primary aim of this study was to investigate the infection pressure, fecundity and infection dynamics of L. salmonis in a west coast sea loch containing salmonid aquaculture. Atlantic salmon held in small sentinel cages were used to monitor sea lice infection pressure in Loch Shieldaig. Investigation of the factors affecting infection pressure within the loch found no evidence of a direct link between monthly gravid lice counts on local farmed salmon and lice burdens on sentinel cage fish. Copepodid L. salmonis were present throughout the year despite there being low numbers of wild salmonids in the system during much of the year and as such the source of this infection was unclear. In subsequent laboratory trials, L. salmonis from wild salmon were found to be more fecund than those from farmed salmon and similarly, fecundity and survival were also higher in summer compared to winter populations of L. salmonis. These findings raise the possibility that L. salmonis infecting wild salmonids may “seed” previously fallowed systems. Alternatively, trials with atypical hosts found that L. salmonis of farmed origin did re-infect Atlantic cod and produce viable egg strings which moulted through to the infective copepodid stage. Infection challenges demonstrated that L. salmonis copepodids were observed to settle on atypical hosts such as saithe and Atlantic cod in low numbers although failed to develop to the chalimus stages and complete its lifecycle. Challenges utilising the mobile pre-adult stage were similarily unsuccesful in allowing L. salmonis to moult to the adult stage on these atypical hosts. Previous work conducted on Pacific three-spined sticklebacks demonstrated the species could support large burdens. In infection trials with three-spined sticklebacks from Scotland’s west coast, settlement was found to be low, which suggests they play no role in the Scottish inshore infection dynamics of L. salmonis. These series of studies provide novel and timely data on the biology and infection dynamics of L. salmonis on typical and atypical hosts in Scottish marine aquaculture areas. The data will form part of the knowledge used to make informed pest management and policy decisions assisting the future development of the aquaculture industry in Scotland.

The present work reports on extensive plankton sampling surveys in a Scottish sea loch used by wild and farmed salmonids and describes the spatial and temporal distribution of planktonic larval sea lice and identifies factors which affect the larval distribution. The planktonic louse larvae recovered were predominantly <i>Lepeophtheirus salmonis</i> (Krøyer) and so the findings of this thesis refer primarily to this species of sea louse. Copepodids occurred in significantly greater densities at 0 m than at a depth of 5 m, whereas nauplii occurred in significantly greater densities at 5 m than at 0 m depth. Densities of caligid nauplii and <i>L. salmonis</i> copepodids recovered from the open-waters of Loch Shieldaig correlated significantly with the counts of gravid <i>L. salmonis</i> on farmed Atlantic salmon at the farm in Loch Shieldaig. Furthermore, the densities of <i>L. salmonis</i> copepodids were significantly correlated  with the estimated total numbers of gravid <i>L. salmonis</i> on all farmed Atlantic salmon in the Loch Torridon management area. Densities of <i>L. salmonis</i> copepodids did not correlate with estimated numbers of gravid <i>L. salmonis</i> on wild salmonids. Atlantic salmon farms were identified as important sources of <i>L. salmonis</i> larvae and these larvae can be transported several kilometres from the point of release. Husbandry louse control practices were indicated to be able to significantly reduce the densities of <i>L. salmonis</i> larvae in the water column. These findings support the principle of synchronised sea louse management at a hydrographic/management area level.

Inventory management and pricing decisions based on quantitative models both in industrial practice and academic works often rely on minimizing expected cost or maximizing expected revenues or profits, which refers to the concept of risk-neutrality of the decision maker. Although many useful insights in operational problems can be obtained by such an approach, it is well understood that incorporating attitudes toward risk is an important lever for building new theories in other fields such as economics and finance. The level of risk associated with an investment might be as important as the expected gain from the investment. Hence, it is necessary to find appropriate measures of risk and the appropriate objectives related to or including these risk measures for inventory control & pricing problems. After the axiomatic foundation of coherent risk measures the application of risk measures to inventory models such as Conditional Value-at-Risk (CVaR) or convex combinations of mean and CVaR became popular. In our work we apply spectral risk measures to the single-period, single-item, linear cost inventory control & pricing problem (also known as newsvendor problem) and derive optimal policies. By doing so, we are able to unify results obtained so far in the literature under the common concept of spectral risk measures for the case of zero and non-zero shortage penalty cost. In particular, we show convexity results and structural properties for the inventory control and, under some assumptions, unimodality results as well as structural properties for the joint inventory & pricing problem. An extensive numerical analysis illustrates the findings. (author's abstract)

Thesis (Ph.D.)--Aberdeen University, 2009. / Title from web page (viewed on June 26, 2009). With: Spatial and temporal distribution of Lepeophtheirus salmonis (Krøyer) larvae in a sea loch containing Atlantic salmon, Salmo salra L., farms on the north-west coast of Scotland / M. J. Penston ... et al. Journal of fish diseases. 2008: 31, 361-371. With: Reduced Lepeophtheirus salmonis larval abundance in a sea loch on the west coast of Scotland between 2002 and 2006 / Michael J. Penston, Colin P. Millar, Ian Davies. Dis. Aquat. Org. 2008: 81, 109-117. Includes bibliographical references.

Phenotypic variation was previously thought to be the result of complex interactions between an individual's genotype and the environment in which it exists. It is, however, now evident that an individual's phenotype may also be shaped by the environmental variation experienced by the mother, i.e. maternal effects. Environmental maternal effects have the potential to generate rapid phenotypic change in a population and so may be particularly important for evolution at ecological time-scales. The general aim of this thesis was to examine how maternal effects may influence offspring fitness and life history traits in Atlantic salmon (Salmo salar L.1758). For this species, the early juvenile period is the most critical due to their complex life cycle. Offspring rely on maternal provisioning during the early stages of development for growth and survival. Several studies on Atlantic salmon have emphasised the benefits of developing from larger eggs, yet it is unclear how the effects of rearing environment influence early life development. The thesis therefore investigated the effects of variation in maternal provisioning and female rearing environment on the development and physiology of embryos, the behaviour of newly emerged fry and the survival of fry released into the wild. Also assessed were the phenotypic changes among juvenile salmon released into the wild compared to those retained in the hatchery. For this maternal provisioning was manipulated by varying the length of time mothers from the same genetic background were maintained in captivity (2 months, 14 months and 26 months). The results of this thesis demonstrate that both maternal provisioning and female rearing environment alter the development and behaviour of salmon fry, opercular beat rate (a proxy for metabolic rate) and yolk sac absorption, and ultimately survival in the wild. Hatchery-reared fry were found to be maladapted to the natural environment for a number of phenotypic traits which are known to impact survival and the longer fry are retained in the hatchery prior to release the more phenotypically mismatched to the natural environment they become. However, increased egg size brought about my retaining females in captivity improved survival.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This research project proposes a supply management model in a consumer goods company in Lima, Peru, to improve stock control and avoid raw materials stockouts and overstock. A Kraljic matrix was used to identify products based on their criticality considering material segmentation, warehouse capacity and times, and ABC segmentation to classify products on each quadrant of the matrix. This project also focuses on defining purchasing and supply strategies in each quadrant of the matrix. This model involves the development of three processes that are related to a new purchasing strategy: economic order quantity, lot-for-lot ordering, and just in time. This new system is based on a more accurate inventory because continuous improvement attracts employees’ attention and engages them in reducing the number of manual notifications made by operators every month. Moreover, after implementing the new procedure for recording inventories, the inventory record was 87% accurate, whereas, in the past, the inventory was not counted and was performed by employees of other areas.

[pt] Os estoques são de suma importância para satisfazer às prioridades competitivas das organizações. O atraso no fornecimento dos materiais à produção acarreta custos pela improdutividade e até mesmo multas pela falta do produto final no prazo. Este trabalho foi elaborado com o objetivo de fazer uma análise das técnicas de gestão de estoque e de como elas podem ser utilizadas na melhoria da produtividade no processo de manutenção de motores, na indústria aeronáutica. Como contextualização desta pesquisa, foi realizada uma revisão bibliográfica de conceitos de gestão de estoque e uma descrição do cenário da manutenção de motores em uma empresa do setor aeronáutico, onde foram verificadas falhas no atendimento do estoque à área de produção e sugeridas medidas de correção. / [en] The warehouses are very important to meet competitive priorities of the organization. The late delivery of the material on production areas increases the costs because of the unproductivity and even fines due to the lack of the final product at the determined time. This essay was prepared with the objective to make an analysis of the warehouse management technics and how their use impact on the improvement of the productivity of the engines maintenance process in the aviation industry. In order to contextualize this research, a bibliographic revision of warehouse management concepts and an explanation of the engine maintenance scenario in aviation industry were performed. Issues on the warehouse supplying parts to the production area were identified and corrections were.

[pt] O varejo brasileiro, tem passado pelo mesmo processo de concentração de empresas, assim como, também acontece com vários outros setores a nível mundial. A estabilidade econômica e concorrentes cada vez mais profissionais forçam as empresas a buscarem a excelência em suas operações. O investimento em estoques para este segmento é elevado, pois as empresas trabalham com uma grande quantidade de produtos, espalhados entre várias filiais e centros de distribuição, preços médios altos e uma grande quantidade de produtos com giro baixo. Fatores sazonais e lançamento de novos produtos alteram a demanda ao longo do tempo, forçando uma resposta rápida para evitar perdas de vendas. A diferença entre o lucro e o prejuízo dos varejistas, pode estar no ciclo de gerenciamento dos estoques. Nesta dissertação, são apresentados os pensamentos de alguns pesquisadores sobre o tema. Após é descrito as informações sobre o mercado e a empresa, em seguida é analisado o sistema de ressuprimento da rede de drogarias e com base no referencial teórico e nos problemas identificados, foi elaborado uma proposta de gerenciamento e otimização dos principais indicadores do sistema de ressuprimento. Os dados foram modelados e os resultados deste modelo são demonstrados no final da dissertação. / [en] The Brazilian retail market has been facing the same players concentration process, as can be seen in many others sectors around the world. The Brazilian economy stabilization and players with more professionalism, require companies to have the excellence in their operations. The investment in stock is too high for this sector, because there are lot of products, located in many stores, distribution centers, products with a high average costs price and many of them have with a low trn over around the time. Seasonal factors and new products launch, changes the demand across the time and requests a quick response to avoid loses. The difference between loss and profit of the retailers can be found in the supply management cycle. This dissertation shows the thoughts from some researches related to the subject been studied. After, the information about the market and the company are described, follows by the supply chain of the drugstore chain analysis. Based on the theory and the problems identified, an alternative way to manage and optimize the supply system is suggested. The model was tested and the results will be show in the end of the dissertation.

A obsolescência de estoques é um evento recorrente nas organizações, demandando o uso de métodos que identifiquem o inventário excessivo antes dele tornar-se obsoleto. Este artigo propõe um método para classificação, projeção e controle da obsolescência de inventários ao longo do tempo, com o objetivo de reduzir o risco de obsolescência ou deterioração futura. A abordagem proposta possui cinco passos, sendo os quatro primeiros dedicados a identificação dos fatores que contribuem para a obsolescência e/ou deterioração do Inventário, a classificação do estoque em categorias e faixas de idade através da análise discriminante, a seleção de variáveis em contexto de PLS, a modelagem de regressão para projeção da idade do inventário ao longo do tempo e a definição de diretrizes para redução do risco de obsolescência. O quinto passo do método utiliza o conceito do ciclo PDCA buscando a melhoria contínua do processo e dos resultados. Na aplicação em dois estudos de caso em indústrias de bens de consumo, o método previu adequadamente o montante do inventário por faixa de idade e o risco de obsolescência ou deterioração do inventário em um horizonte de seis meses. / Inventory obsolescence is a prominent phenomenon in organizations, requiring the use of methods that identify excessive inventory before it becomes obsolete. This paper proposes a method to classify, forecast and control the obsolescence of inventories over time in order to reduce the risk of future obsolescence or deterioration. The proposed approach has five steps, the first four of which are dedicated to identifying the factors that contribute to the obsolescence and/or deterioration of the Inventory, the classification of the inventory into categories and age ranges through discriminant analysis, the selection of variables in the context of PLS, regression modeling to forecast the age of inventory over time and the definition of guidelines for reducing the risk of obsolescence. The fifth step of the method uses the concept of the PDCA cycle seeking for the continuous improvement of process and results. In the application in two case studies in consumer goods industries, the method predicted the amount of inventory by age range and the risk of obsolescence or deterioration of the inventory over a six-month horizon.