No description available.

<p>Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzo-furans (PCDFs) belong to the most toxic compounds known to science and they are defined as Persistent Organic Pollutants (POPs) under the Stock-holm Convention. The general human exposure to PCDD/Fs is primarily through dietary intake. The importance of contaminated sites as secondary PCDD/F sources (i.e. sources that once received its contamination from a primary source) are getting increased attention. To be able to assess the risks for human exposure at PCDD/F contaminated sites, the environmen-tal distribution of PCDD/Fs and the potential mobilization between dif-ferent environmental media (e.g. food chain transfer) must be known. The primary aim of the work presented in this thesis was to investigate human exposure pathways associated with PCDD/F contaminated sites by combining field measurements and modeling. Site specific field measurements were made at a PCDD/F contaminated site in Sweden and multimedia modeling scenarios were evaluated against site specific data and national reference data.</p><p>The results show that the congener distributions in exposure media affected by contaminated soil may differ significantly from the distribu-tions found in media from reference locations. Higher chlorinated PCDD/Fs may be transferred into food chains where they contribute to a large fraction of the toxic equivalent concentration (TEQ). Ingestion of locally produced animal food may be an important exposure pathway al-ready at low or moderate PCDD/F soil concentrations. However, the con-gener composition of the source is critical for the exposure. The signifi-cance of the individual exposure routes varies depending on e.g. the spatial distribution and magnitude of the soil contamination, the pro-perties of the exposure media and the human behavior. Multimedia mo-deling can be used in risk assessments as long as model algorithms and model parameters are representative for the superhydrophobic properties of PCDD/Fs. However, selection of physical-chemical PCDD/F properties is a challenge due to large variation in reported values. For some proper-ties, data is scattered or completely lacking</p>

Polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzo-furans (PCDFs) belong to the most toxic compounds known to science and they are defined as Persistent Organic Pollutants (POPs) under the Stock-holm Convention. The general human exposure to PCDD/Fs is primarily through dietary intake. The importance of contaminated sites as secondary PCDD/F sources (i.e. sources that once received its contamination from a primary source) are getting increased attention. To be able to assess the risks for human exposure at PCDD/F contaminated sites, the environmen-tal distribution of PCDD/Fs and the potential mobilization between dif-ferent environmental media (e.g. food chain transfer) must be known. The primary aim of the work presented in this thesis was to investigate human exposure pathways associated with PCDD/F contaminated sites by combining field measurements and modeling. Site specific field measurements were made at a PCDD/F contaminated site in Sweden and multimedia modeling scenarios were evaluated against site specific data and national reference data. The results show that the congener distributions in exposure media affected by contaminated soil may differ significantly from the distribu-tions found in media from reference locations. Higher chlorinated PCDD/Fs may be transferred into food chains where they contribute to a large fraction of the toxic equivalent concentration (TEQ). Ingestion of locally produced animal food may be an important exposure pathway al-ready at low or moderate PCDD/F soil concentrations. However, the con-gener composition of the source is critical for the exposure. The signifi-cance of the individual exposure routes varies depending on e.g. the spatial distribution and magnitude of the soil contamination, the pro-perties of the exposure media and the human behavior. Multimedia mo-deling can be used in risk assessments as long as model algorithms and model parameters are representative for the superhydrophobic properties of PCDD/Fs. However, selection of physical-chemical PCDD/F properties is a challenge due to large variation in reported values. For some proper-ties, data is scattered or completely lacking

Enterococcus faecium è un componente fondamentale del microbiota di diversi alimenti fermentati quali formaggi e salumi e viene spesso isolato in alto numero in alimenti pronti al consumo. É inoltre largamente utilizzato come probiotico sia per l’uomo che per gli animali. Allo stesso tempo, però, questa specie batterica rappresenta una delle cause principali di infezioni nosocomiali quali endocarditi ed infezioni al tratto urinario. Studi recenti hanno dimostato che la specie E. faecium è costituita da due sub-popolazioni principali: la prima è denominate hospital associated (HA) clade “A” ed include la maggior parte dei ceppi responsabili di infezioni umane; la seconda è chiamata community associated (CA) clade “B”, e contiene principalmente ceppi commensali dell’uomo. Analisi più approfondite hanno rivelato un ulteriore suddivisione all’interno del clade A, nel sub-clade A1 (che raggruppa la maggioranza dei ceppi clinici) e nel sub-clade A2, associato agli animali e più sporadicamente ad infezioni umane. Nel 2012, EFSA ha redatto una linea guida per la valutazione della sicurezza di E. faecium usato come probiotico per gli animali, concludendo che i cepi appartenenti all’hospital-associated clade non devono essere utilizzati in nutrizione animale. Comunque, la distinzione tra le due sub-popolazioni è stata fatta utilizzando dati ottenuti prevalentemente da isolati umani e animali e solo un numero limitato di ceppi isolati dagli alimenti è stato considerato. Obiettivo di questa tesi di dottorato è stato quello di valutare la sicurezza di E. faecium negli alimenti fermentati, considerando ceppi isolati da formaggi artigianali e prodotti carnei e utilizzando sia tecniche di genomica che analisi fisiologiche. Nessuno dei ceppi alimentari studiati è risultato parte del clade A1, ma un ceppo isolato da un salame stagionato pronto al consumo ha rivelato diversi tratti tipici dei ceppi A1, tra cui particolari IS, transposase e geni di resistenza agli antibiotici. Questi risultati, così come altri dati, sottolineano la necessità di approfondire le conoscenze circa il ruolo dei ceppi di E. faecium isolati da alimenti come fattore di rischio per la salute umana. / Enterococcus faecium is commonly found in high numbers in ready to eat foods, being a member of the bacterial communities of a variety of fermented foods, including cheese and sausages, and is widely used as human and animal probiotic. However, this bacterial species is a leading cause of nosocomial infection, mainly endocarditis and urinary tract infections. Recent studies have demonstrated that E. faecium species consists of two very distinct clades: the hospital associated (HA) clade “A”, which includes most of the strains responsible for human infections, and the community associated (CA) clade “B”, that contains primarily human commensal isolates. Deeper analysis revealed a further split within clade A into sub-clade A1 (which groups the vast majority of clinical isolates), and sub-clade A2, associated with animals and sporadic human infections. In 2012, the European Food Safety Authority has issued a guideline for the safety assessment of E. faecium used as animal probiotics, concluding the strains belonging to the hospital-associated clade should not be used in animal nutrition. However, the differentiation of the two clades has been performed using data mainly deriving from human and animal isolates, and only a limited number of strains from the food chain were considered. Aim of this doctoral thesis was to assess the safety of E. faecium in fermented food, considering strains isolated from artisanal cheese and meat products, and using both whole genome-based techniques and physiological studies. None of the food isolates studied in this work belong to the epidemic clade A1, however a strain isolated from a ready to eat salami revealed several A1-specific traits, such as specific IS, transposases and antibiotic resistance genes. These results, as well as other data, underline the emergency of deeper understanding the role of E. faecium isolated from fermented foods as risk factor for human health.

Made available in DSpace on 2016-06-02T19:52:00Z (GMT). No. of bitstreams: 1 5215.pdf: 2573740 bytes, checksum: b0159c517597ec5097315a913808cb47 (MD5) Previous issue date: 2012-10-05 / Financiadora de Estudos e Projetos / Brazil is the largest producer and exporter of the world market of frozen concentrated orange juice (FCOJ), and the State of São Paulo stands out as the largest producer and exporter of that commodity in Brazil. In recent years, the State of Paraná has increased its production and export of FCOJ. Through the survey of secondary data and interviews with key players, this study identified and evaluated the main critical aspects of the competitiveness of the agri-food chain of FCOJ in Paraná. Through the rapid appraisal method (method of quick research) were possible to evaluate 11 drivers of competitiveness, focusing on the links of agricultural production and processing of that chain. A total of 24 interviews were conducted, using questionnaires and interviews screenplays. It was possible to identify which are the drivers of competitiveness, considered in the context of this research, which are considered favorable, neutral and unfavorable for the competitiveness of the links of agricultural production and processing of the agri-food chain of FCOJ in Paraná. From these analyses it was also possible to verify that none of the drivers of competitiveness, considered in this dissertation, was regarded as very favorable or very unfavorable for the competitiveness of the link of agricultural production of that chain. From these analyses it was also possible to verify that none of the drivers of competitiveness, considered in this dissertation, was regarded as very favorable for the competitiveness of the link of processing of that chain, and only a driver of competitiveness, of the set of drivers considered in this dissertation, was regarded as very unfavorable for the competitiveness of the link of processing. The analyses allowed to point out proposals for public policies and private strategies to enhance the competitiveness. In a general context, it was possible to conclude that the links of agricultural production and processing of the agri-food chain of FCOJ in Paraná have a great potential to continue to expand in Paraná. The citriculture in Paraná has a great potential to expand because it has a good technology, a good production capacity and productivity and a sufficient amount of available agricultural land to extend the exploration of the citriculture in Paraná, in addition, the economic agents that act in the citriculture in Paraná have contracts for the supply of orange to the economic organizations that have manufacturing plants that produce FCOJ in Paraná, so these contracts ensure the sale of the most part of the Paraná s orange production, which is good for the citrus growers who act in Paraná. The processor sector of orange also has a great potential to expand in Paraná because it has agro-industrial technologies of good level and a good production capacity, in addition to be able to expand without great difficulties its manufacturing capacity of FCOJ, moreover, the existence of contracts for orange supply between economic organizations who act in processing and citrus growers in Paraná, secures the supply of oranges, considered of good quality, for the producing plants of FCOJ installed in Paraná. / O Brasil é o maior produtor e exportador do mercado mundial de suco de laranja concentrado congelado (SLCC), sendo que o Estado de São Paulo destaca-se como o maior produtor e exportador nacional dessa commodity. Nos últimos anos, o Estado do Paraná tem aumentado a sua produção e exportação de SLCC. Por meio de levantamento de dados secundários e de entrevistas com agentes-chaves, identificou-se e avaliou-se os principais aspectos críticos da competitividade da cadeia agroindustrial de SLCC no Paraná. Por meio do método rapid appraisal (método de pesquisa rápida) foi possível avaliar 11 direcionadores de competitividade, com foco nos elos de produção agrícola e de processamento dessa cadeia. Um total de 24 entrevistas foram realizadas, utilizando-se de questionários e roteiros de entrevistas. Foi possível identificar quais são os direcionadores de competitividade, considerados no âmbito desta pesquisa, que são considerados favoráveis, neutros e desfavoráveis para a competitividade dos elos de produção agrícola e de processamento da cadeia agroindustrial paranaense de SLCC. A partir dessas análises também foi possível verificar que nenhum dos direcionadores de competitividade, considerados nesta dissertação, foi considerado como muito favorável ou muito desfavorável para a competitividade do elo de produção rural da cadeia agroindustrial paranaense de SLCC. A partir dessas análises também foi possível verificar que nenhum dos direcionadores de competitividade, considerados nesta dissertação, foi considerado como muito favorável para a competitividade do elo de processamento da cadeia de SLCC no Paraná, e somente um direcionador de competitividade, do conjunto de direcionadores considerados nesta dissertação, foi considerado como muito desfavorável para o desempenho competitivo do elo de processamento. As análises permitiram apontar propostas de políticas públicas e estratégias privadas que possam aumentar a competitividade. Em um contexto geral, pode-se concluir que os elos de produção rural e de processamento da cadeia agroindustrial de SLCC no Paraná têm um grande potencial para continuar a se expandir no território paranaense. A citricultura, no Paraná, tem um grande potencial para se expandir porque ela dispõe de boa tecnologia, de boa capacidade de produção e produtividade e de quantidade de terra agrícola disponível considerada como suficiente para ampliar a exploração da atividade citrícola no estado, além disso, os agentes econômicos que atuam na citricultura paranaense possuem contratos de fornecimento de laranja com as organizações econômicas que possuem usinas produtoras de SLCC instaladas no Paraná, assim, esses contratos asseguram a comercialização da maior parte da produção paranaense de laranja, o que é algo bom para os citricultores que atuam no Paraná. Já o setor processador de laranja também tem um grande potencial para se expandir no Paraná porque ele dispõe de tecnologias agroindustriais de bom nível e de boa capacidade de produção, além de ter condições de ampliar, sem maiores dificuldades, a sua capacidade de fabricação de SLCC, além disso, a existência de contratos de suprimento de laranja entre as organizações econômicas que atuam no processamento citrícola e os citricultores, no Estado do Paraná, assegura o abastecimento de laranja, considerada de boa qualidade, para as usinas produtoras de SLCC instaladas no Paraná.

Fish and shellfish are important sources of protein for the world population. Nearly 50 percent of fish and shellfish products originate from aquaculture, and the rest comes from traditional fishing. The marine stocks are under threat from unsustainable fishing practices. Together with fishing, aquaculture constitutes extra stress on the marine stocks and ecosystems. Aquaculture also causes other environmental side effects. International trade rules do not sufficiently take care of the ecological problems. Voluntary initiatives, like ecolabels, are one way of dealing with the problems. This thesis does an attempt to, from an environmental science perspective, analyze how the fish counters at four ICA Kvantum stores in the Stockholm region work with ecological sustainability issues with regards to fish and shellfish. The overall purpose is to examine the shops’ historical, current and potential future work and to analyze if the work is conducted in a proactive, reactive or in a passive way. The main findings include that the knowledge, sustainability statuses, responsiveness, and changes in time, and the intentions or plans for the future differed a lot between the different shops. Furthermore, many of the investigated potential problem areas seemed to constitute problems in practice. Additionally, it seemed like additional pressure may be needed if the aggregated ecological status should be raised. The research method consisted of case studies with semistructured qualitative interviews and analysis of corporate documents, and a minor quantitative investigation of the frozen assortment at the stores. / Fisk och skaldjur är en viktig proteinkälla för världens befolkning. Nära hälften av fisk- och skaldjursprodukterna internationellt kommer idag från akvakultur (fiskodlingar). Resten kommer från traditionellt fiske. De marina fisk- och skaldjursbestånden hotas i olika grad av ohållbart fiske. Tillsammans med fisket utgör olika former av akvakultur påfrestningar mot fisk- och skaldjursbestånd och de marina ekosystemen. Akvakultur orsakar även andra ekologiska sidoeffekter. Internationella handelsregler tar idag inte tillräcklig hänsyn till de ekologiska problemen. Frivilliga initiativ såsom miljömärkningar har uppkommit och kan eventuellt utgöra en del av lösningarna på problemen. Denna kandidatuppsats gör utifrån ett miljövetenskapligt perspektiv ett försök att analysera hur ”fiskdiskarna” i fyra ICA Kvantumbutiker i Stockholms län arbetar med ekologisk hållbarhet vad gäller fisk och skaldjur. Övergripande syftet är att undersöka livsmedelsbutikernas historiska, nuvarande och potentiella framtida arbete med de ekologiska hållbarhetsfrågorna, samt att analysera om de arbetar utifrån ett proaktivt, reaktivt eller passivt angreppssätt. Huvudresultaten visar att arbetet mellan butikerna skiljde sig mycket med avseende på kunskaper, ekologiska hållbarhetsteman, proaktivitet/ reaktivitet/ passivitet, förändringar över tiden, samt vad gäller intentioner och planer för framtiden. Vidare så verkade flera av de studerade ekologiska problemområdena på olika sätt utgöra verkliga problem. Någon form av påtryckningar verkade vara nödvändigt om butikernas arbete, aggregerat sett, skulle ställas om till en mer ekologiskt hållbar status. Metoden utgjordes av fallstudier med semistrukturerade kvalitativa intervjuer och studier av utvalda centrala dokument från ICA-koncernen relaterade till det tematiska undersökningsområdet. En mindre kvantitativ utvärdering av butikerna frysta sortiment gjordes också.

There is a widespread distribution of possibly toxic heavy metals, such as zinc, in aquatic ecosystems. Simultaneously aquatic food webs are changing due to declining predatory fish stocks. In this study, I examine how such an alteration of the food chain, the disappearance of a top trophic level, can affect the uptake and transfer of pollutants in lower trophic levels. I investigate a tri-trophic food chain containing resources (zooplankton), consumer fish, and predatory fish and use zinc as an example pollutant. This is done by constructing and adding a pollutant module to a stage-structured biomass model. The combined model is based on a system of eight ordinary differential equations to study the zinc concentrations in the consumer fish population in two scenarios: in the presence or absence of predatory fish, i.e., the food chain consists of either three or two trophic levels. The results show that the removal of the predator affects the concentration of the pollutant in the consumer population. In the absence of predators, the uptake of zinc from food is smaller and the zinc concentration is lower in the consumer fish population. The results remain the same for different values of the pollutant-specific parameters, i.e., uptake rate from water, assimilation efficiency, and efflux rate. This could indicate that food chain dynamics have a strong influence on the uptake and transfer of pollutants. Furthermore, this means that even if the model is parametrized to zinc in this study, the modeling tool can also be used for other pollutants with similar biokinetics as zinc. The results from this study highlight the importance to include food chain structure and dynamics when studying the uptake and transfer of pollutants. The novel knowledge and the developed tool from this study could advantageously be included to a higher degree when discussing the impact of pollution on aquatic ecosystems and mitigation measures. / Det finns en utbredd spridning av potentiellt giftiga tungmetaller, som t.ex. zink, i akvatiska ekosystem. Samtidigt förändras akvatiska födovävar på grund av minskande rovfiskbestånd. I denna studie undersöker jag hur en sådan förändring av födoväven, ett försvinnande av en trofisk toppnivå, kan påverka upptaget och överföringen av föroreningari lägre trofinivåer. Jag undersöker en tritrofisk födokedja som innehåller resurser (zooplankton), konsumentfisk och rovfisk och använder zink som ett exempel på förorening. Detta görs genom att konstruera och addera en föroreningsmodul till en stegstrukturerad biomassamodell. Den kombinerade modellen bygger på ett system med åtta ordinära differentialekvationer för att studera zinkhalterna i konsumentfiskpopulationen i två scenarier: i närvaro eller frånvaro av predatorer, dvs. födokedjan innehåller antingen tre eller två trofiska nivåer. Resultaten visar att koncentrationen av föroreningen i konsumentpopulationen förändras när födokedjan ändras. När rovfiskar saknas i systemet är upptaget av zink från föda mindre och zinkkoncentrationen lägre i konsumentfiskpopulationen. Resultaten förblir detsamma för olika värden på de föroreningsspecifika parametrarna, d.v.s. upptagshastighet från vatten, assimileringseffektivitet och utflödeshastighet, vilket skulle kunna indikera att födokedjans dynamik har ett starkt inflytande på upptag och överföring av föroreningar. Vidare innebär detta att även om modellen har parametriserats till zink i denna studie, så kan modelleringsverktyget även användas för andra föroreningar som har en liknande biokinetik som zink. Resultaten från denna studie understryker vikten av att inkludera födokedjans struktur och dynamik när man studerar upptag och överföring av föroreningar. Den nya kunskapen och det utvecklade verktyget från denna studie skulle med fördel i högre grad inkluderas när man diskuterar föroreningars påverkan på akvatiska ekosystem och vilka åtgärder som bör sättas in för att minska problemen.

No description available.

Elevated levels of trace elements in the environment are of great concern because of their persistence, and their high potential to harm living organisms. The exposure of aquatic biota to trace elements can lead to bioaccumulation, and toxicity can result. Furthermore, the transfer of these elements through food chains can result in exposure to human consumers. Sea-fill or coastal fill sites are among the major anthropogenic sources of trace elements to the surrounding marine environment. For example, in the Maldives, Thilafushi Island is a sea-fill site consisting of assorted municipal solid waste, with multiple potential sources of trace elements. However, there is limited data on environmental trace element levels in the Maldives, and although seafood is harvested from close to this site, there is no existing data regarding trace element levels in Maldivian diets. Following the Christchurch earthquakes of 2011,

由於國際連鎖速食業地區經營者（Market Operator）的主要資本投入，包括：原料採購、餐飲設備投資、設計裝修、人員訓練、以及租用不動產時，都牽扯到被陷入或轉換成本偏高的問題，以致對於既有資源供應商之續約談判時處於不利的地位。 　　本研究主要從交易成本理論、陷入成本及專屬資產、買賣方之交易關係等理論解析國際連鎖速食店的地區經營者提高取得上述資源的議價能力（Bargaining Power）的管理策略，並透過業界專家實證其可行性。 　　經研究結果顯示，國際速食連鎖業地區經營者可以從「降低專屬陷入成本的投入」、「促使主要供應商投入專屬資產」、「善用其他交易影響者的力量」等三個方向來提高議價能力，並可根據資源特性的不同，而採取不同的策略行動。