Dissertations / Theses on the topic 'Food web studies'

Master of Science
Department of Computing and Information Sciences
Daniel Andresen
FNPRS program offers nutrition education all over the counties in Kansas. It is necessary to keep track of the budget expenses for the program, resources used and many other parameters involved in the program. There exist number of commodities and products in the process of educating people. Research is needed to determine which value-added products or processes are economically possible and what percentage of it is accepted by people. For these issues, it is very important to maintain this information in a database and generate reports accordingly. The aim of the project is to create a web interface for users to enter the program information regarding the various programs conducted by Family Nutrition Program. The various kinds of data include information about the budget for the program, information about the various collaborating agencies, various kinds of resources used, services provided, proposed equipment and travel funds etc. Users for this application are county agents who take the responsibility of conducting the program and managing their data. Creating a web interface provides a solution to facilitate the agents to manage their data more efficiently and to monitor their records on a day to day basis. It also aims for generating reports for Family Nutrition Program in order to keep a check over their advancements in the program. This project involves handling of various kinds of information such as FNP Proposals, Agent information, FNP Funds, Collaborating Agencies. Database maintenance is made simple thereby allowing the administrators to add as much as data possible and manage accordingly.

Includes bibliographical references (p. 305-338).
This thesis examines representations of food in twenty-first century media, and argues that the media obsession with food in evidence today follows directly from U.K. and U.S. post-war industrial and economic booms, and by the associated processes of globalisation that secure the spread of emergent trends from these countries to the rest of the so-called Western world. The theoretical frame for the work is guided in large part by Guy Debord's Society of the Spectacle (1967), which follows a Marxist tradition of examining the intersection between consumerism and social relationships. Debord's spectacle is not merely something to be looked at, but functions, like Marx's fetishised commodity, as a mechanism of alienation. The spectacle does this by substituting real, lived experience with representations of life. Based on analyses of media representations of food from the post-war period to the present day, the work argues against the discursive celebration of globalisation as a signifier of abundance and access, and maintains, instead, that consequent to the now commonplace availability of choice and information is a deeply ambiguous relationship to food because it is a relationship overwhelmingly determined by media rather than experience. It further argues that the success of food media results from a spectacular conflation of an economy of consumerism with the basic human need to consume to survive. Contemporary celebrity chefs emerge as the locus of this conflation by representing figures of authority on that basic need, and also, through branded products (including themselves), the superfluity of consumerism. The subject of the work, therefore, is food, but the main object of its critique is media. Food media from World War 2 to the World Wide Web is about the commodification of history and politics, through food, and the natural (super)star of this narrative is the modern celebrity chef.

An influence at one trophic level can result in dynamic impacts also on other components of a food web. These dynamics are known as trophic cascades, and can be both top-down and bottom-up. After a near-collapse of the Baltic cod Gadus morhua stock in the 1980s, its main prey sprat Sprattus sprattus increased dramatically. The main food of sprat, marine copepods, decreased during the same time period, likely a combined effect of increased predation pressure from sprat and decreasing salinities. This shortage of food for sprat resulted in decreasing quality of sprat as a food source for common guillemots Uria aalge. However, a recent increase in fishing for sprat has again resulted in better feeding conditions for guillemots.

Human impacts on this simple food web can be complex. In the early 20th century, marine mammals were abundant and nutrient levels were low in the Baltic Sea. This thesis illustrate that this situation corresponded to lower fish biomass. A reduction of seals early in the century led to reduced top-down control, which resulted in increasing fish stocks. Later, in the 1950s, the largest inflow of salt water during the century mobilized accumulated phosphorus from the deep sediments, which stimulated nitrogen fixation. Combined with increasing anthropogenic nutrient loads, this led to increased primary production and a rapid change from an oligotrophic to a eutrophicated state. This change can be termed a regime shift, which also stimulated fish production. Subsequent over-fishing of cod likely caused a second regime shift, from a cod- to a clupeid- dominated state, which led to the described effects on the common guillemots.

Several factors affect the life-history of this long-lived seabird. Bycatches in gillnet fisheries is one factor directly affecting guillemot survival, and the proportion of bycatches increased during a period of increasing fishing effort. Surprisingly, avian cholera, a previously undocumented disease in common guillemots, was found at times to cause considerable adult mortality. Common guillemot life-history information can communicate the diversity of factors influencing marine ecosystems – hopefully this can increase our understanding of how complex even "simple" food webs are.

To predict the impact of future disturbances such a climate change and introduction of non-native species on ecosystems, it is important to understand how disturbances may affect community composition. This is inherently diffcult since species may be expected to respond differently to disturbances such as elevated temperatures or the introduction of a new species. Furthermore, since the species in an ecosystem are interlinked by energy, nutrient and information transfers, disturbances may be amplified or absorbed, depending on the nature of the disturbance and the resilience of the ecosystem. Some species have a disproportionate effect on ecosystem function and are often referred to as keystone species. By definition the loss of a keystone species causes a catastrophic change in community composition. Therefore, the identification of keystone species could help to target conservation efforts more effciently. A dynamical food web model, representative for a chalk stream (the River Frome, Dorset) was developed and manipulated. Changes in community composition and biodiversity were assessed. For the identification of keystone species each species node was removed in turn. Although impacts were found, particularly after the removal of important prey nodes and top predators, no catastrophic shift was observed and, consequently, no keystone species were identified. Impacts of species introductions were assessed by adding representative model species to the food web. The largest impact was observed after the addition of a small competitor at intermediate trophic level. The addition of a top predator had moderate impact, whereas no negative impact was found after the addition of a larger bodied species at intermediate trophic level. Possible impacts of climate change, specifically elevated temperatures, were assessed by increasing the metabolic rates of the species nodes. No impacts were found, when energy inputs were raised accordingly, but severe impacts, were observed when energy inputs were restricted. In general, the ecosystem was considered fairly resilient to most of the tested disturbances, possibly owing to the high natural variability of the community. The findings of current study suggest that rather than focusing conservation efforts on single species, the focus should be on 'keystone structures' that maintain high ecosystem resilience.

Shell organic matrix proteins in fossils are valuable geochemical archives for studying ancient environments and food webs. Compound-specific studies of stable carbon isotope ratios offer particularly good resolution of trophic level of consumers and the identities of primary producers and can be used to detect diagenetic alteration of isotopic ratios. To interpret compound specific isotope data, however, controlled diet studies in the laboratory are needed to reveal trophic enrichment patterns of 13C in tissues and shell organic matter. This study examines the relationship between d 13C of 11 amino acids in diet, soft tissues, and shell organic matter in laboratory-cultured Strombus alatus, an herbivorous marine gastropod. The d 13C values of amino acids in this animal's foot and mantle tissues are consistently enriched in 13C relative to the diet. Phenylalanine (+1.8 ppm) and alanine (+3.8 ppm) showed the least fractionation between diet and tissues, while aspartic acid (+10.7 ppm) and glutamic acid (+14.6 ppm) showed the greatest enrichment. On average, nonessential amino acids exhibited greater enrichment than did essential amino acids (+7.1 ppm vs. + 4.1 ppm). Shell organic matter amino acids showed a very similar pattern, with aspartic and glutamic acids again showing the greatest enrichment (+7.2 ppm and +11.1 ppm respectively). Nonessential amino acids in shell (+4.9 ppm) were also more enriched than the essential amino acids (+3.5 ppm). Overall, the carbon isotopic compositions of amino acids in shell organic matrix appear to parallel those in animal tissue, validating the utility of employing this material as a surrogate for animal tissue in fossil samples. Interpreting trophic position information in consumers is difficult, however, as the variation in the magnitude of trophic enrichments for glutamic and aspartic acids between species, tissue types and diet is still poorly understood. As phenylalanine has the most consistent diet-consumer enrichments, the most suitable application for d 13C isotope analysis at this time is the reconstruction of base food sources.

The main theme of this thesis is the interactions of animals with the environment and each other. The thesis was written within the framework of a biomanipulation project “Pikeperch in Himmerfjärden”. With the aim to investigate possible trophic pit-falls, give the manipulation the best possible start, and find ways to monitor the progression of the manipulation. In Paper I the diet of the invader cladoceran Cercopagis pengoi is analysed with stable isotopes; conducted prior to stocking. C.pengoi has a preference for large copepods, indicating possible competition with fish. Paper II investigates the behavioural differences between pikeperch fingerlings reared in different environments (pond vs. tank). Results suggest that fish reared in semi-natural ponds are more likely to survive directly after stocking. In Paper III and IV, the diel vertical migrations (DVM) of copepods are in focus. In Paper III the migrations of two copepod species: Acartia spp. and Eurytemora affinis are studied over season and life stage. The amplitude of migration was found to increase with ontogeny for both species, indicating evasion of visual predators. Paper IV examines the varying migratory patterns of adult female E. affinis finding that these animals migrate more actively when feeding conditions deteriorate and growth decreases. The overall conclusions of the thesis are that behavioural, not only direct trophic interactions are key when studying ecosystems.

At the time of the doctoraldefense, the following papers were unpublished and had a status asfollows: Paper2: In press. Paper 4: Manuscript.

Objetivo: O principal objetivo deste estudo foi desenvolver e validar um método computadorizado para avaliação do consumo alimentar, preenchido por indivíduos adultos utilizando a Web. Metodologia: Foi desenvolvido um sistema computadorizado contendo base de dados de alimentos provenientes das principais Tabelas de Composição de Alimentos. No total, 561 indivíduos manifestaram interesse em participar da pesquisa. Após os critérios de exclusão adotados, 93 indivíduos fizeram parte da amostra. Para a validação, foi utilizado como método de referência o Recordatório de 24 horas (R24h) aplicado por telefone. Foi solicitado o preenchimento de 3 registros alimentares (RAPls) on-line em dias alternados e, no dia seguinte ao seu preenchimento, os mesmos indivíduos foram entrevistados por telefone. Utilizaram-se teste de Kolmogorov-Smirnov e ajustes pela variância intrapessoal e pela energia para as variáveis dietéticas, coeficientes de correlação de Pearson e de Spearman, teste t-pareado e teste de Wilcoxon, classificação dos indivíduos em quartis, Kappa ponderado e os gráficos de 81and Altman. Resultados: A amostra final foi constituída por 60 indivíduos, dos quais 72% eram do gênero feminino e 70% possuíam curso superior completo. Em relação ao estado nutricional, 55% dos entrevistados eram eutróficos. Lipídio, cálcio, ferro, sódio, vitamina 86 e vitamina C apresentaram médias estatisticamente iguais entre ambos os métodos. Os coeficientes de correlação após os ajustes foram todos estatisticamente significantes e variaram de 0,31 (Vitamina 86) a 0,87 (energia). A concordância bruta entre os quartis após o ajuste variou de 40% (carboidratos) a 61,7% (energia), enquanto para os quartis opostos variou de 6,7% (vitamina C) a 21,7% (sódio). Observou-se que todos os nutrientes e energia apresentaram valores acima de 0,40 para o Kappa ponderado. Conclusões: O sistema computadorizado NutriQuanti, quando preenchido por usuários da internet, apresentou bom desempenho para classificar os indivíduos segundo seu consumo de energia e os nutrientes avaliados
Objective: The main purpose of this study was to develop and validate a self-administered computerized method to assess food consumption in adults using the internet. Methods: A computerized program containing a food nutrient database from the main food composition tables has been developed. Five hundred and sixty one individuais have manifested interest in participate in the study. After application of the exclusion criteria, the sample consisted of 93 individuais. For validation of the computerized method, the 24h-recall method administered by telephone was used as reference. The individuais were asked to complete 3 food records on the internet, in alternate days. After completing each food record, the same individuais were interviewed by telephone. The following statistical tests were used: Kolmogorov-Smirnov, adjustment for the intraindividual portion of the variance and for energy intake for the diet variables, Pearson and Spearman correlation coefficients, t-test for paired samples and Wilcoxon test, cross-c1assification, weighted Kappa and 81and Altman graphics. Results: The final sample consisted of 60 individuais, of whom 72% were female and 70% had completed graduated course. As far as nutritional status, 55% were eutrophic. Mean intake of fat, calcium, iron, sodium, vitamins 86 and C were statistically the same (similar) between the two methods. After adjustment, all correlation coefficients were statistically significant and varied from 0.31 (Vitamin 86) to 0.87 (energy). The raw concordance between quartiles, after adjustment, varied from 40% (carbohydrate) to 61.7% (energy), and for the opposite quartiles varied from 6.7% (vitamin C) to 21.7% (sodium). Ali the nutrients, as well as the energy, have shown values above 0.40 for the weighted Kappa test. Conclusions: The self-administered on-line NutriQuanti computerized program has performed well when classifying the individuals according to their energy and nutrient intake.

The importance of different sources of carbon (energy) supporting secondary productivity in estuaries and coastal waters is still rather uncertain, despite decades of research on this topic. One of the major uncertainties is the relative importance of carbon from macrophyte detritus and microalgae, particularly diatoms and cyanobacteria within sediments (microphytobenthos, MPB). Existing methods have been unable to determine their relative contributions to consumer nutrition. This thesis addresses some of the limitations of existing methods, and then uses an innovative combination of techniques to determine the relative contributions of detritus and MPB to the nutrition of consumers within a mangrove forest in southeast Queensland, Australia. To ensure wide applicability, techniques were developed for both mud and sand, encompassing the range of sediments encountered in estuaries and protected coastal waters. Stable isotope analysis is commonly used to resolve food web issues. Difficulty extracting MPB from sediment to obtain a pure carbon isotopic signature (δ13C), however, has hampered efforts to determine the importance of MPB as a carbon source for consumers. I showed that compound-specific isotope analysis of phytol, part of the chlorophyll molecule, can be used to estimate MPB δ13C with enough precision for most food web studies: within 1-1.8‰ of actual values (95% CI) at normal levels of replication (n = 5 or 10). Although the majority of phytol in sediments is produced in situ by MPB, part of the phytol pool is derived from detritus (e.g. 33% for mud, 17% for sand in the current study). In some situations, this could lead to errors in estimating MPBδ13C, realistically by about 1‰ (in sand) or 2‰ (in mud), but an adjustment can be made where necessary. Compound-specific isotope analysis of phytol (the phytol method) can therefore be confidently used to estimate MPB δ13C values in estuarine environments. Where δ13C values of detritus and MPB are similar, natural abundance stable isotopes are unable to resolve their contribution to consumer nutrition. Enrichment of producers with the heavy 13C isotope generates distinct δ13C values that can be traced into consumers. Studies aiming to enrich MPB using 13C-enriched sodium bicarbonate have, however, observed simultaneous enrichment of bacteria. This may simply be due to use of MPB-derived carbon by bacteria, but if bacteria acquire the label directly, enrichment of consumers would indicate use of bacteria, rather than MPB, as a primary carbon source. Application of 13C-enriched bicarbonate resulted in enrichment of MPB in both mud and sand and subsequent secondary enrichment of bacteria. Direct bacterial uptake was trivial in comparison to MPB uptake. Any labelling of animals in subsequent enrichment experiments could therefore be attributed to use of MPB as a primary carbon source. I used a combination of the phytol method, stable isotope enrichment, and compartment modelling within a mangrove forest to examine use of detritus and MPB as carbon sources for common consumers; crabs (Australoplax tridentata and Parasesarma erythrodactyla) and foraminifera (Ammonia beccarii and Trochammina inflata). Compartment modelling quantified the extent of use through comparison of producer and consumer enrichment over time. The main carbon source for T. inflata was unable to be established, but all other species acquired virtually all of their carbon locally (within a 1 m radius), from MPB and/or mangrove detritus. The majority of carbon for A. tridentata was derived from MPB (99%), whereas P. erythrodactyla and A. beccarii predominantly utilised mangrove detritus (88 and 84%, respectively). For the latter two species, the remainder of carbon was derived from MPB. The different strategies in carbon utilisation by the crab species indicate feeding selectivity that may be a strategy to avoid interspecific competition for food resources. The high abundance of benthic invertebrates and their rapid assimilation of local carbon sources highlight their potential importance in influencing carbon cycling and productivity in estuaries. Consumption of benthic invertebrates by more mobile, higher consumers may also allow for transport of locally-produced carbon to adjacent waters via trophic relay. The methods demonstrated in this thesis have potential application in resolving food web issues in a variety of habitats. Further application of these techniques at a variety of temporal and spatial scales would help to develop a broader understanding of the importance of macrophyte detritus and MPB, and establish general patterns in utilisation of carbon sources in estuarine systems.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment
Faculty of Environmental Sciences
Full Text

Mountain lakes are an iconic feature of the landscape in the Mountain West. They hold significant ecological and cultural value, and are important sentinels of environmental change. Despite their pristine image, these remote waterbodies are subjected to numerous anthropogenic stressors. Mountain lakes are naturally fishless systems, but historical fish stocking has led to major changes in mountain lake food web structure, including declines of resident amphibians, large-bodied zooplankton, and emergent insect populations. Atmospherically deposited contaminants, such as mercury, can accumulate in mountain lake food webs, leading to relatively high levels in the fish relative to the water. Managing for these stressors is difficult, because although fish stocking causes ecological problems, and mercury bioaccumulation poses human health risks, the cultural value of angling remains important. The goal of this dissertation was to better understand the issues of fish stocking and mercury bioaccumulation in a socioecological context: from the importance of trophic dynamics for mercury bioaccumulation in mountain lake fish, to the implications fish stocking and mercury bioaccumulation for mountain lake management. In Chapter 2, I identified the ecological, limnological, and landscape-level indicators of mercury bioaccumulation in mountain lake food webs in order to inform better ecosystem management. In Chapter 3, I conducted an experiment to test if fatty acid stable isotopes can partition benthic and terrestrial prey sources in fish in a simplified mountain lake food web, in hopes of providing a more informative tool for future food web studies. In Chapter 4, I used intercept surveys to determine the public perceptions of mountain lake fisheries management in two national parks, and assess the risk mercury may pose to mountain lake anglers by determining fish consumption habits. I determined that nearshore forest cover and fish diet were the best predictors of mercury concentrations in mountain lake fish, but that our understanding of the role of terrestrial prey subsidies for fish is constrained by limitations in current diet tracing methods. My experiment demonstrates that using stable isotopes of fatty acids is a promising approach to distinguishing between benthic and terrestrial diet sources, but that doing so effectively requires an in-depth understanding of physiological context specific to the ecosystem of interest. Lastly, through my surveys, I found that thousands of anglers regularly consume fish from mountain lakes, and that while most visitors have concerns about the ecological impacts of fish stocking, anglers support a conservation-based approach that balances ecological health with the cultural value of fish stocking. This dissertation provides a unique set of tools that advance our understanding of food web dynamics and mercury bioaccumulation in mountain lakes, as well as the social value of these ecosystems. My results suggest that the most effective way to protect the health of mountain lakes and their visitors will be for managing agencies to collaborate with scientists and angling groups when making fisheries management decisions, and to invest in outreach about both the ecological and toxicological implications of fish stocking and mercury bioaccumulation in mountain lakes. The use of such socioecological research approaches is becoming progressively more important, as the threats of climate change and unstable regulatory protections for mountain ecosystems increase.

A majority of carbon in freshwater and marine ecosystems is in the form of ultraplankton, heterotrophic and autotrophic plankton &<&5 &\mu&m including heterotrophic bacteria, Prochlorococcus, cyanobacteria, and autotrophic eucaryotes. However, ultraplankton and subsequently microbial food webs have yet to be incorporated into models of benthic-pelagic coupling despite the preponderance of macroinvertebrates with the capacity to feed on ultraplankton. I have examined the role of microbial food webs in benthic-pelagic coupling in three ecosystems: Lake Baikal, Siberia, Russia; Gulf of Maine, Northwest Atlantic Ocean; and Conch Reef, Florida Keys, USA. Using sponges as a model organism and in situ measurements, I have quantified (1) suspension feeding on ultraplankton and (2) release of dissolved inorganic nitrogen (DIN) and phosphorus (DIP) resulting in direct evidence that benthic macroinvertebrates do occupy the level of primary consumer within the microbial food web. Dual-beam flow cytometry was employed to quantified sponge suspension feeding on five types of ultraplankton: heterotrophic bacteria, Synechococcus-type cyanobacteria, autotrophic picoplankton &<&3 &\mu&m, autotrophic eucaryotes 3-10 &\mu&m, and in marine ecosystems Prochlorococcus. Grazing by the freshwater sponges Baikalospongia intermedia and B. bacilliferia and the boreal marine sponge, Mycale lingua, was unselective for all types of ultraplankton with efficiencies ranging from 63-99%. This is the first time that grazing on Synechococcus-type cyanobacteria and Prochlorococcus by macroinvertebrates has been quantified in freshwater and marine ecosystems. Conversely, the coral reef sponges Ircinia felix and I. strobilina release significant amounts of DIN and DIP as a result of grazing on procaryotic plankton. Using a general model for organism-mediated fluxes, it is conservatively estimated that through active suspension feeding sponges in Lake Baikal retain 1.97 g C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and M. lingua retains 29 mg C day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& while at Conch Reef sponges released 204 &\mu&mol DIN day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}& and 48 &\mu&mol DIP day&\sp{lcub}-1{rcub}& m&\sp{lcub}-2{rcub}&. A majority of the carbon retained at all three locations was from procaryotic cell types suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.

Small-scale family farming to meet household food and livelihood needs is a central activity for most households in rural Malawi. Food insecurity and malnutrition are persistent problems for these farmers. Conventional agriculture techniques and maize production are the focus of most household farming, government agriculture policy, and agricultural development programs. However, conventional agriculture and maize production are expensive and unreliable in the short term, and environmentally and financially unsustainable in the long term. As an alternative, some NGOs and farmers in Malawi use permaculture, an agroecology design and low external input agriculture system. Previous research and NGO reports have pointed to benefits and constraints to permaculture adoption in Malawi.

For this dissertation, I investigated the relationships between agriculture practices and food security among smallholder conventional and permaculture farmers in Lilongwe Rural District in Malawi in partnership with two implementing permaculture organizations. Building on political ecology, the anthropology of food, structural violence, and permaculture literatures, I analyzed the impact of permaculture practice on farmers' agricultural practices, diet, and food security. This analysis showed that farmers who used permaculture experienced agricultural, environmental, livelihood, and food and nutrition security benefits in comparison to farmers who solely used conventional agriculture. These benefits were important given the context of structural violence in which farmers face systemic risk to impoverishment, food insecurity, and malnutrition. However, the benefits of permaculture use were constrained by the broader agro-food system, resource entitlements, and other structural constraints. The findings of this study add to our understanding of how smallholder farmers in Malawi can maneuver within the broader agro-food system, while pointing to potential strategies that farmers and organizations can use to try to address existing constraints.

Background: Food has many different functions. On a physical level, it is needed to survive and to maintain health, but it also has many social, psychological, and emotional meanings. For example, food is used to build relationships, to mark hierarchies, to celebrate holidays, and to influence mood and self-image. Different foods have different cultural meanings, and people are socialized from an early age to recognize and utilize their symbolic value. One arena where food occupies a central position is the Swedish school subject Home and Consumer Studies (HCS), which focuses on both the physical and the psychosocial dimensions of food-related health. Since these dimensions are not always compatible, the aim of this dissertation was to explore how students and teachers of HCS use big 'D' Discourses to talk about and handle food, with a special focus on vegetables, meat, vegetarian food, and sweet foods. Methods: Fifty-nine students and five teachers were observed, recorded, and in some cases video-taped. Participants’ talk about vegetables, meat, vegetarian food, and sweet foods was transcribed verbatim and analysed for big 'D' Discourses. Results: Students mostly based their choice of vegetables on sensory and cultural Discourses. Some vegetables were mandatory and others were optional, depending on whether or not they were part of a recipe or a cultural tradition. The health Discourse was only used if a specific assignment demanded it, and was closely tied to the evaluation Discourse. Contrary to the sometimes optional status of vegetables, meat was seen as central in the sensory, cultural, health, and social Discourses. Therefore the reduction of meat could be problematic. It was regarded as simultaneously healthy and unhealthy, and it could elicit disgust, but whenever participants talked about decreasing meat consumption, its centrality was invoked as a counterargument. As an extension of this, vegetarian food was seen as 'empty', deviant, and an unattainable ideal. Access to vegetarian food was limited for meat-eaters, and vegetarians were othered in both positive and negative ways. When vegetarian food was cooked during lessons, it was constructed as something out of the ordinary. Sweet foods could be viewed as a treasure, as something dangerous and disgusting, or as an unnecessary extra. Home-made varieties were seen as superior. Sweet foods gave social status to both students and teachers, and they could be traded or given away to mark relationships and hierarchies, but also withheld and used to police others. Conclusion: In summary, two powerful potential opposites met in the HCS classroom: the Discourses of normality (sensory, cultural, and social Discourses), and the Discourses of responsibility (health and evaluation). Normality could make physically healthy food choices difficult because of participants' social identity, the conflicted health Discourse, and too-strict ideals. On the other hand, some people were excluded from normality itself, notably vegetarians, who were seen as deviant eaters, and teachers, who had to balance state-regulated goals in HCS against local norms. To counteract such problems, teachers can 1) focus on sensory experiences, experimental cooking methods, and already popular foods, 2) challenge normality by the way they speak about and handle different types of food, 3) make cooking and eating more communal and socially inclusive, 4) explore the psychosocial dimension of health on the same level as the physical dimension, and 5) make sure they do not grade students' cultural backgrounds, social identities, or taste preferences. This might go some way towards empowering students to make informed choices about food and health. However, scant resources of things like time, money, and equipment limit what can be achieved in the subject.
Mat har många olika funktioner. Rent fysiskt behöver vi den för att överleva och behålla hälsan, men den har också en rad sociala, psykologiska och känslomässiga betydelser. Exempelvis används mat för att bygga relationer, för att markera hierarkier eller tider på dagen och för att påverka humöret och självbilden. Olika livsmedel har olika symboliskt innehåll, och barn socialiseras tidigt in i ett visst sätt att äta och tänka kring mat. Ett område där mat har en central plats är det svenska skolämnet hem- och konsumentkunskap (HKK). I kursplanen finns ett starkt fokus på både fysisk och psykosocial hälsa, men för en del människor kan dessa dimensioner ibland vara mer eller mindre inkompatibla. Därför ville jag i denna avhandling undersöka hur lärare och elever pratar om och hanterar olika sorters mat i HKK och vad detta kan få för konsekvenser för lärandet om hälsa. Jag observerade och spelade in fem lärare och 59 elever med mp3-spelare under 26 HKK-lektioner på fem olika skolor. I vissa fall där jag fick tillåtelse filmade jag också det som hände. Därefter transkriberade jag allt tal om grönsaker, kött, vegetarisk mat och sötsaker och analyserade detta tal med hjälp av diskursanalys för att få reda på vad deltagarna i studien sade "mellan raderna", det vill säga hur deras världsbild kring olika livsmedel såg ut. Resultatet visade att elever i de flesta fall var fria att välja grönsaker utifrån den egna smaken, förutom när receptet gjorde en viss grönsak obligatorisk eller när en skoluppgift krävde att man skulle ta hänsyn till hälsa. När läraren ansåg att en grönsak var obligatorisk var det mycket svårt för eleven att undvika den, medan däremot grönsaker som bara sågs som tillbehör i många fall blev ignorerade. Vad gällde hälsa kunde grönsaker vara "allmänt nyttiga", men oftare var de bärare av ett specifikt näringsämne som behövdes för att lösa en skoluppgift. I några fall sågs de som tomma och värdelösa. Kött var centralt och svårt att avstå ifrån, inte bara på grund av smaken utan även för att det "hörde till" de flesta rätter och gav livsviktiga näringsämnen. Samtidigt som det sågs som hälsosamt kunde det också vara farligt, eftersom man kunde äta för mycket protein eller mättat fett. Kött kunde användas som relationsbyggare mellan elever och för att markera status i klassen, så att de som riskerade att hamna utanför var rädda att inte få lika mycket kött som andra. Protein sågs som viktigt och var kopplat till manlighet, muskler och styrka. I motsats till kött sågs vegetarisk mat som "tom", annorlunda och ett ouppnåeligt ideal. Det var svårt för icke-vegetarianer att få tillgång till vegetarisk mat, förutom när det utgjorde ett särskilt lektionstema. Maten sågs som bristfällig eftersom den inte innehöll kött, och den krävde extra planering för att se till att man fick i sig alla aminosyror. Det kunde vara socialt krångligt att vara vegetarian eftersom det krävde extra jobb av kompisar och skolkökspersonal, men många respekterade vegetarianens val och ansträngde sig för att göra en särskild portion åt dem. Sötsaker var åtråvärda, men också farliga, äckliga eller onödiga. Hemgjorda bakverk hade högre status. Sötsaker kunde användas för att markera vem man var kompis med och inte, men gav även upphov till konflikter när elever hade olika åsikt om det "perfekta resultatet" eller när de var rädda att inte få rättvisa mängder. På grund av sötsakernas koppling till sjukdom och viktuppgång kunde de också användas för att peka ut och nedvärdera dem som åt för mycket eller vid fel tillfälle. Sammanfattningsvis förekom två huvudgrupper av diskurser: normalitet och ansvar. Å ena sidan sågs smak, kultur och sociala ritualer som viktigt när man talade om och valde matvaror, men å andra sidan krävde ämnet att man såg på mat ur ett mer vetenskapligt hälsoperspektiv. Synen på normalitet gjorde det svårt att välja fysiskt hälsosam mat eftersom social identitet, den motsägelsefulla synen på hälsa och alltför strikta ideal stod i vägen. Å andra sidan fanns det personer som inte hade tillgång till normalitet, såsom vegetarianer och även lärare, som tvingades balansera statligt uppställda mål inom ämnet mot en lokalkultur med delvis andra värderingar. För att motverka dessa problem kan lärare 1) fokusera på sensorisk träning, experimentell matlagning och måltider som bygger på redan populära rätter, 2) utmana synen på normalitet genom sitt sätt att prata om och hantera olika sorters mat, 3) jobba för att göra matlagningen och måltiderna mer socialt inkluderande, 4) utforska den psykosociala dimensionen av hälsa på samma nivå som den fysiska för att elever ska kunna resonera kring sina matval utifrån smak, kultur och sociala relationer, och 5) undvika fällan att betygsätta elevers smak och kulturella bakgrund. Denna typ av undervisning skulle kunna ge elever fler verktyg för att kunna göra självständiga hälsoval, men det förutsätter att läraren får tillräckligt med resurser i form av lektionstid, förvaringsutrymme och en budget som möjliggör ett brett sortiment av livsmedel.

ABSTRACT

The conditions on the market are rapidly changing and businesses in Sweden need to seize signals of change in time, in order to have a strong market position. The ability to make the right decisions and react in time is vital due to the increasing competition and a mistake can have devastating consequences for a company. The aim of this thesis is to investigate what tools and methods businesses use to analyse the surrounding world, which has lead to following research question:

How do businesses analyse the surrounding and predict trends and what factors in the society should a company be attentive to while performing an analysis?

Analyses of the surrounding heritage from a term called Business Intelligence, which consist of internal and external factors. This thesis focuses of analyses of external factors, in other words the surrounding. These external aspects enrich the understanding of the internal factors and together they are the foundation that strategic planning originates from. An analysis can be performed in many different ways for instance with collaborations with consultants or by observing the society. A World Mapping method can be used to chart trends or important changes and a company can also try to identify unpredicted events by using the factor X-model. Theories by Bengt Wahlström have also been used in the study to display how trends can be analysed.

This study will analyse large food producers who have established brands on the Swedish market. A qualitative approach has been conducted where six food supplier companies and three consultant companies specialised in analysing the surrounding have been interviewed. The method has been deductive where the empirical findings has been analysed with the theoretical framework. The outcome of the research shows that collaborations with consultants is a commonly used instrument and practical methods such as scenario planning and in real life scanning are preferred as visualising factors simplifies the managing of them. Media plays a significant role, both as a tool to search and track trends but also as a tool that can increase the affect of trends and unforeseen occurrences.

Sandy beach ecosystems have been studied worldwide; however, ecological data are sparse for the extensive barrier islands of Florida. Accordingly, I investigated the feeding patterns of the ghost crab (Ocypode quadrata), a dominant omnivore inhabiting beaches along the Floridian coast. Density data was collected for ghost crabs and swash macroinfaunal prey. In addition, I utilized stable isotopes in conjunction with the mixing models IsoSource and SIAR to characterize diets of ghost crabs across three barrier islands in spring and summer 2011. Results showed that ghost crabs at Cayo Costa feed primarily on swash macroinfauna, while those from Anclote Key shifted their diet to one comprised primarily of semi-terrestrial amphipods. However, at Honeymoon Island, ghost crab isotopic signatures were best explained by a mixed diet of both macroinfauna and wrack-associated prey. The unique consumption of wrack fauna at Anclote Key co-occurs with comparatively low infaunal densities and biomass, and modified ghost crab behavior due to trait-mediated effects. My results are novel because they suggest that wrack-associated fauna may be an important food source for ghost crabs in certain beach regimes.

碩士
國立臺灣大學
海洋研究所
99
The seas around Taiwan are characterized by various marine habitats. But very few benthic communities were surveyed in the deep-sea areas. The deep-sea areas are inhabited by diversified organisms with highest biodiversity between the depths of 1000-2000 meter. Most deep-sea ecosystems rely on the organic particles, such as planktonic and mammal carcasses or bodys, sinking from the euphotic and mesopelagic zones to the seafloors. However, only 1–10% of the material produced in the euphotic zones can reach to the deep-sea floors. Therefore, this study aim to evaluate the biodiversities between deep-sea areas and shallow areas by sampling 6 stations with bottom trawling at different depths from South China Sea and eastern coast of Taiwan in summer 2008 and 2009.. Another aim is to understand the food source and the food web structure of demersal organism by stable isotopic anaylsis. The highest biodiversities were found at the depth between 1000 to 2000 meters, and the biodiversities in the euphotic zone were higher than the twilight zone. Five trophic levels were identified in the deep-sea benthic ecosystem, and only 3 trophic levels were found in shallow benthic ecosystem. Organic materials produced in the euphotic zone were the main food for the benthic ecosystem except the St.5 in I-Lan coast, which received mostly land-derived organic matter. Previous studies showed that organic matter during the sinking process will be repeatedly catabolized by micro-organisms and enrich the δ15N of the organic matter. We also found that δ15N of suspension feeders, predator/scavengers, fishes and crabs was positively correlated with the depth. The δ15N of deposit feeder, shrimp, and all benthic organisms had no significant relationship with depth. Food sources of benthic ecosystem are not necessarily confined to the ocean surface. In the deep-sea benthic communities, the organic matter was continuously recycled to maintain a stable ecosystem. Higher δ15N for the organisms in the deeper zone indicated that organic matters sinking from the euphotic zone were the important nitrogen source to deep-sea benthic communities.

碩士
義守大學
生物科技學系
105
As a famous Chinese proverb stated in the biography of Li Shi Qi from the historical record of Han dynasty, that "People are the most important to an emperor, while foods are the most important to the people". It points out so clearly that the well-being of the ruler’s people should be the utmost concern to him, and this concern is best addressed by keeping his people well fed. During the period from late 2013 to early 2014, there had been outburst of food safety scandals regarding oil quality. In order to make more profit, food manufacturers not only shrug their shoulders and ignore consumers’ well-being, they also refined and repackaged those oils and sold them to clients. The series of incidents had put people at risk, and crushed consumers’ confidence in the safety of the food supply. This study is an evaluation and review of the adulterated cooking oils that these two companies, Chang Chi Foodstuff Factory Co., Ltd, and Wei Chuan Foods Corporation, how they breached the Act Governing Food Safety and Sanitation regulations and how the food law was inadequate to regulate the misfeasance. The current food law fails to meet the General Principles of Chapter I, Article 1, that “This Act is enacted to govern the food sanitation, safety, and quality, and protect the health of citizens.” From my study, the following conclusions had been drawn out from the study: 1. Fake oil scandals had exposed the failure of Taiwan’s food hygiene and safety system, which should be reviewed urgently. 2. The authorities, involved in this incident, fail in their vertical and horizontal communication and cooperation. 3. Food and Drug Administration has released a revised version of "Food Safety and Health Management Law" on December 16, 2015.

Beginning in the early 1600s, dam construction in New England obstructed anadromous fish access to spawning grounds during migration. As a result, anadromous forage fish populations have declined, which has impacted freshwater, marine, and terrestrial ecosystems. To determine the impacts of dams on anadromous forage fish and freshwater ecosystems, I used historical and current data to estimate population changes in alewives (Alosa pseudoharengus) from 1600-1900. A significant reduction in spawning habitat occurred in New England as a result of 1,642 dams constructed between 1600 and 1900, resulting in 14.8% and 16.6% lake and stream habitat remaining by 1900, respectively. In eight New England watersheds, this translates to an estimated cumulative annual loss of 30 B juvenile alewives available as freshwater forage and 538 M year 1, 2 and 3 alewives available as marine forage. The cumulative annual lost number of adult return spawners was conservatively 17 M fish, or 3,642 metric tons. Lost marine-derived nutrients from adult return spawners were 11 T phosphorus, 64 T nitrogen, and 410 T carbon. A comparison of predator fish growth and condition in alewife and non-alewife lakes showed that white perch (Morone Americana) and yellow perch (Perca flavescens) have higher condition in early summer in lakes with alewives. Predator growth rates (length-at-age) were significantly higher in early life stages (ages 1 and 2) when alewives were present, but significantly lower in late life stages (ages 3 and older). Results indicate a greater maximum length obtained by mature fish when alewives are absent, and an earlier age and length at maturity when alewives are present. These results indicate significant ecosystem impacts of lost anadromous forage fish, with bottom-up trophic effects across multiple time scales and biological processes. An ecosystem-based management approach should be used by inland and marine aquatic managers, and ecosystem connectivity and trophic interactions should be considered when managing migratory fish and prioritizing restoration goals.