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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Speiseinsekten: Rechtliche Regelungen und Eignung von Untersuchungsmethoden zur Nährwertbestimmung

Schiel, Laura 26 May 2023 (has links)
Insekten besitzen das Potenzial, als alternative Nahrungsquelle einen Beitrag zur Sicherstellung der Ernährung der wachsenden Weltbevölkerung zu leisten. Rechtlich gelten sie gemäß Vorgaben der Verordnung (EU) 2015/2283 als neuartige Lebensmittel und dürfen im Rahmen der Übergangsvorschriften dieser Verordnung unter bestimmten Voraussetzungen bereits in der Europäischen Union vermarktet werden. Da sie als wirbellose Tiere bisher aus dem Anwendungsbereich vieler Vorgaben herausfallen, stellen die rechtliche Beurteilung und vergleichbare Ergebnisgenerierung im Rahmen der amtlichen Lebensmittelüberwachung besondere Herausforderungen dar. Ziel der vorliegenden Dissertation ist es, die Nutzung, das Inverkehrbringen und die Planung von Untersuchungsschwerpunkten durch die amtlichen Lebensmittelüberwachungs- sowie Untersuchungsbehörden, Produzenten und Lebensmittelunternehmer zu erleichtern, indem die aktuelle Rechtslage zum Thema Speiseinsekten zusammengefasst und die Anwendbarkeit von Methoden der Amtlichen Sammlung von Untersuchungsverfahren geprüft wird. Außerdem werden die Besonderheiten der Spezies Honigbienen-Drohnenbrut herausgestellt. Zur Beurteilung der aktuellen Rechtslage erfolgte neben der Einbeziehung der EU-Gesetzgebung eine Abfrage von 28 EU-Mitgliedsstaaten sowie der zuständigen Behörden für die Lebensmittelüberwachung der 16 Bundesländer in Deutschland bezüglich des aktuellen Umgangs mit Speiseinsekten und zu Änderungen, die im Zusammenhang mit den Übergangsregelungen der Verordnung (EU) 2015/2283 stehen. Zur Prüfung der Anwendbarkeit der Methoden der Amtlichen Sammlung von Untersuchungsverfahren nach § 64 Lebens- und Futtermittelgesetzbuch für die Parameter Wasser, Asche, Rohprotein, Fett und Natrium als standardisierte Methoden zur Bestimmung der Nährwerte, wurden vier Insektenspezies ausgewählt. Für diese lag bereits ein Antrag als neuartige Lebensmittel vor und sie repräsentierten die Variabilität dieser Lebensmittelmatrix. Nach Probenvorbereitung und Homogenitätstest erfolgte ein Werteabgleich mit vier Laboren. Um die Ergebnisse mit den entsprechenden Vorgaben zu vergleichen, wurden mit der Hilfe von unabhängigen Zielstandardabweichungen z-Scores berechnet und zur Leistungsbewertung herangezogen. In einem Übersichtsartikel wurden zudem Informationen zu der Nährstoffzusammensetzung, Sensorik, bisherigen Verwendungsmöglichkeiten, zum rechtlichen Rahmen und zu Risiken von Drohnenbrut als Lebensmittel zusammengefasst. Außerdem erfolgten mittels Flüssigchromatographie mit Massenspektrometrie-Kopplung Untersuchungen zum Nachweis von Pestizidrückständen in 37 Drohnenbrutproben. Die Darstellung der geltenden rechtlichen Aspekte sowie deren Umsetzung in den EU-Mitgliedsstaaten sowie in den Bundesländern in Deutschland zeigen, dass der gesetzliche Rahmen des Inverkehrbringens von Speiseinsekten bisher nicht mit dem von Lebensmitteln anderer Kategorien vergleichbar ist. Die Notwendigkeit der Anpassungen der gültigen Vorgaben vor allem in den Bereichen Kennzeichnung, allgemeinen Hygienevorschriften, tierseuchen-, tierschutz- sowie umweltrechtlichen Aspekten wurde herausgestellt. Es konnte außerdem nachgewiesen werden, dass die überprüften Methoden zur Bestimmung der Parameter Wasser, Asche, Rohprotein, Gesamtfett und Natrium die spezifischen Anforderungen für gefrorene Speiseinsekten erfüllen. Damit können sie nach einer Verifizierung als standardisierte Methoden von Laboren eingesetzt werden. Im Rahmen der eigenen Untersuchungen konnten keine Pestizidrückstände in Drohnenbrut detektiert werden. Auch die Zusammenfassung der bisherigen Studien ergaben keine Gefahren für die Verbraucher. Aufgrund der geringen Datenmengen sollten jedoch weitere Studien und regelmäßige Kontrollen durchgeführt werden. Die vorliegende Dissertation liefert für Produzenten, Unternehmer, gesetzgebende Institutionen und überwachende Behörden einen Überblick darüber, welche Vorgaben aktuell gelten und welche rechtlichen Überarbeitungen zukünftig notwendig sind. Außerdem wurde mit Hilfe der neuen Erkenntnisse die Beurteilung von Insektenproben nicht nur vereinfacht, sondern auch vereinheitlicht und damit vergleichbar gemacht. Da bisher keine Gefahren ausgehend von Drohnenbrut als Lebensmittel festgestellt werden konnten, ist deren Nutzung nicht nur ökologisch und ernährungsphysiologisch sinnvoll, sondern kann daneben einen Baustein zur Sicherstellung der Versorgung der anwachsenden Menschheit liefern. Von besonderer Bedeutung für die Etablierung von Speiseinsekten auf dem deutschen Markt sind die zeitnahe Publikation einer nationalen Leitlinie sowie Aufklärungsarbeit bezüglich Insekten als Lebensmittel zu leisten.
92

Genetic Engineering As Literary Praxis: A Study In Contemporary Literature

Evans, Taylor 01 January 2012 (has links)
This thesis considers the understudied issue of genetic engineering as it has been deployed in the literature of the late 20th century. With reference to the concept of the enlightened gender hybridity of Cyborg theory and an eye to ecocritical implications, I read four texts: Joan Slonczewski's 1986 science fiction novel A Door Into Ocean, Octavia Butler's science fiction trilogy Lilith's Brood – originally released between 1987 and 1989 as Xenogenesis – Simon Mawer's 1997 literary novel Mendel's Dwarf, and the first two books in Margaret Atwood's speculative fiction MaddAddam series: 2003's Oryx and Crake and 2009's The Year Of the Flood. I argue that the inclusion of genetic engineering has changed as the technology moves from science fiction to science fact, moving from the fantastic to the mundane. Throughout its recent literary history, genetic engineering has played a role in complicating questions of sexuality, paternity, and the division between nature and culture. It has also come to represent a nexus of potential cultural change, one which stands to fulfill the dramatic hybridity Haraway rhapsodized in her "Cyborg Manifesto" while also containing the potential to disrupt the ecocritical conversation by destroying what we used to understand as nature. Despite their four different takes on the issue, each of the texts I read offers a complex vision of utopian hopes and apocalyptic fears. They agree that, for better or for worse, genetic engineering is forever changing both our world and ourselves.
93

Genética de populações e relações de parentesco em Ciconiiformes (Aves)

Miño, Carolina Isabel 06 August 2010 (has links)
Made available in DSpace on 2016-06-02T20:20:30Z (GMT). No. of bitstreams: 1 3280.pdf: 5102569 bytes, checksum: f511b08e43998ea79e0f9b0ac5ed969b (MD5) Previous issue date: 2010-08-06 / Universidade Federal de Sao Carlos / Population genetic parameters and genetic relatedness estimates were carried out for Roseate Spoonbill (Platalea ajaja), Wood Stork (Mycteria americana) and Great Egret (Ardea alba egretta) reproductive colonies in Amapa, Pantanal and Rio Grande do Sul (RS), Brazil. Microsatellite genotypes were used to investigate kinship patterns between nestlings sampled inside the same nests, using a variety of analytical approaches. Unrelated nestling-pairs were observed in Roseate Spoonbill nests (6.12% of analyzed nests) and in Wood Stork nests (11.34%); half-siblings were present in Roseate Spoonbill nests as well (1.36%). Only full-siblings were detected inside Great Egret nests. Conspecific brood parasitism (CBP) and extra-pair paternity were proposed to account for the presence of unrelated nestmates and half-siblings, respectively, in Roseate Spoonbill and Wood Stork nests. Those results suggest the occurrence of a mating system different than genetic monogamy in natural populations of those waterbirds. Genetic relatedness was also investigated for adults and offspring, as well as for supposed siblings in Roseate Spoonbill families kept in three zoological facilities in the U.S. Paternity and maternity allocation analyses through maximum-likelihood revealed that errors were present in zoo‟s studbooks in relation to the familial records. We also identified mating between related individuals that were not detected previously by zookeepers. Population genetic parameters were also estimated and demographic processes were assessed for Great Egret reproductive colonies in the Pantanal and Rio Grande do Su, Brazil. Bayesian clustering analyses, assignment tests, analysis of molecular variance, F-statistics estimates, allelic frequency distribution and the G-W index revealed that: i) Pantanal reproductive colonies are genetically differentiated from Rio Grande do Sul colonies; ii) an IBD-like pattern alone cannot explain that differentiation; and iii) genetic signal of a reduction of population size was present for two colonies in the Pantanal and one in Rio Grande do Sul. Results were discussed considering a metapopulation dynamic and also considering that populations from both Brazilian regions represent distinct units and deserve to be treated separately when planning and carrying out conservation and management programs that aim to preserve the species‟ genetic diversity. / Estudos de genética de populações e de parentesco genético foram desenvolvidos em colhereiro (Platalea ajaja), cabeça-seca (Mycteria americana) e garça-branca-grande (Ardea alba egretta), de colônias reprodutivas do Amapá, Pantanal e Rio Grande do Sul (RS), Brasil. Genótipos em locos de microssatélites foram utilizados para se investigar os padrões de relacionamento entre ninhegos amostrados dentro dos mesmos ninhos com diferentes metodologias de análise. Pares de ninhegos não-relacionados foram encontrados nos ninhos de colhereiro (6,12% dos pares analisados) e de cabeça-seca (11,34%); meio-irmãos foram observados nos ninhos de colhereiro (1,36%). Em garça branca grande foi detectada apenas a presença de irmãos-completos dentro dos ninhos. Parasitismo de ninho intraespecífico e paternidade extra-par podem explicar a presença de ninhegos não-relacionados e meio-irmãos nos ninhos de colhereiro e cabeça-seca, o que indica a presença de um sistema de acasalamento diferente da monogamia genética nas populações naturais dessas espécies. Relações de parentesco entre adultos e filhotes e entre supostos irmãos foram determinadas em famílias de colhereiro de três zoológicos dos EUA. Análises de atribuição de maternidade e paternidade por máxima verossimilhança revelaram erros nos registros dos zoológicos quanto às relações progenitor-progênie e identificaram acasalamentos entre indivíduos aparentados que não tinham sido registrados. Parâmetros genético-populacionais e processos demográficos foram investigados em populações de garça-branca-grande do Pantanal e do Rio Grande do Sul. Análises Bayesianas, testes de alocação de indivíduos, análises de variância molecular, estimativa de estatísticas F, exame da distribuição das freqüências alélicas e cálculo do índice de G-W permitiram identificar que: i) há diferenciação genética significativa entre colônias reprodutivas do Pantanal e do Rio Grande do Sul; ii) o padrão de isolamento pela distância não explica essa diferenciação; e iii) duas populações no Pantanal e uma população no RS apresentaram sinais genéticos de redução demográfica. Os resultados foram discutidos considerando que as populações de garça-branca-grande localizadas no Pantanal e no Rio Grande do Sul são unidades populacionais independentes e devem se tratar separadamente no planejamento e desenvolvimento de programas de manejo para a conservação da diversidade genética total da espécie.
94

Garça-vaqueira (Bulbucus ibis): a diversidade genética no estudo do comportamento reprodutivo e na caracterização da população invasora brasileira

Silva, Emmanuel Moralez da 05 March 2013 (has links)
Made available in DSpace on 2016-06-02T20:20:34Z (GMT). No. of bitstreams: 1 4932.pdf: 1990172 bytes, checksum: 7025c9dd589a8c2a6771bc24539895b5 (MD5) Previous issue date: 2013-03-05 / Universidade Federal de Sao Carlos / The genetic diversity of the cattle egret (Bubulcus ibis) was analyzed to investigate reproductive behavior and characterize Brazilian populations of the species. Genotypes at seven microsatellite loci were used to investigate the occurrence of more than one female laying eggs in the same nest, characterizing the occurrence of multiple maternity. DNA was extracted from swabs collected from the outer surface of eggs and sexed; males were excluded. Forty-eight clutches from two breeding seasons (2010 and 2011) were genetically analyzed. Thirty-nine eggs laid by a second or third female were recorded. In five nests, the first egg of the clutch was from a different female, the laying happening prior to that of the incubating female. Suggesting nest takeover by another pair of egrets that kept the pre-existing eggs together with its own clutch. In the other 43 nests, the hypothesis of brood parasitism was posed to explain why one or two additional females were found laying eggs in a nest. A 463-bp fragment of the mitochondrial DNA control region Domain I was amplified for 148 individuals from seven Brazilian populations to investigate genetic-population and demographic parameters. Genetic diversity indices, the population structure tests Fst and AMOVA, a haplotype network, mismatch distribution and neutrality tests (Tajima s D, Fu s Fs, Fu and Li s D* and F*, Ramos-Onsins and Rozas R2) revealed the following: i) a high level of diversity was recorded for the cattle egret in Brazil in comparison to other closely related species studied in the country; ii) genetic diversity levels determined for the Brazilian regions are similar; iii) genetic structuring was not observed between the seven studied populations; and iv) the different tests performed to determine demographic expansion revealed no significant results. This is the first genetic characterization study for Bubulcus ibis to date and the findings indicate a high degree of plasticity in reproductive behavior and confirm a marked dispersion behavior of the species, leading to the homogenization of Brazilian populations. / A diversidade genética da garça-vaqueira (Bubulcus ibis) foi utilizada para se investigar o comportamento reprodutivo e para se caracterizar populações brasileiras da espécie. Genótipos em locos de microssatélites foram utilizados na detecção da presença de mais de uma fêmea ovipositando em um mesmo ninho, o que pode caracterizar a ocorrência de maternidade múltipla. O DNA extraído dos swabs coletados na superfície externa dos ovos foi sexado e eventuais amostras de machos foram excluídas. Quarenta e oito ninhadas, de duas temporadas reprodutivas (2010 e 2011) foram analisadas geneticamente. Foram registrados 39 ovos ovipositados por uma segunda ou terceira fêmea. Em 33 ninhos foram encontrados genótipos distintos de duas fêmeas e em seis ninhos genótipos de três fêmeas. Em cinco ninhos o primeiro ovo na sequência de oviposição mostrou-se ser de uma fêmea diferente, tendo a oviposição acontecido previamente àquela da fêmea incubante. Esse achado foi explicado supondo a tomada de ninho por um segundo casal de garças, com a manutenção do ovo pré-existente juntamente com os da própria ninhada. Nos outros 43 ninhos, a presença das fêmeas extras foi explicada hipotetizando a ocorrência de parasitismo de ninho intraespecífico. Um fragmento de 463 pb do Domínio I da região controladora do DNA mitocondrial foi amplificado para 148 indivíduos para a investigação de parâmetros genéticopopulacionais e processos demográficos nas sete populações estudadas. A estimativa de índices de diversidade genética, testes de estruturação populacional Fst e AMOVA, a construção de uma rede de relação entre haplótipos, a análise de mudanças no tamanho populacional pela mismatch distribution e a realização de testes de neutralidade (D de Tajima, Fs de Fu, D* e F* de Fu e Li, R2 de Ramos-Onsins e Rozas) permitiram identificar: i) um nível alto de diversidade genética para B. ibis no Brasil, quando comparado a espécies proximamente relacionadas estudadas no país; ii) níveis semelhantes de diversidade genética determinados para as regiões brasileiras; iii) ausência de estruturação genética entre as sete populações estudadas; e iv) ausência de sinais de expansão demográfica pelos testes realizados. Os resultados aqui apresentados são os primeiros resultados genéticos na espécie até o momento e apontam para uma alta plasticidade no comportamento reprodutivo e confirmam a dispersão bastante acentuada da espécie, levando a homogeneização das populações brasileiras.
95

Identification of optimal broodstock for Pacific Northwest oysters

Stick, David A. 06 December 2011 (has links)
The United States Pacific Northwest is well known for its shellfish farming. Historically, commercial harvests were dominated by the native Olympia oyster, Ostrea lurida, but over-exploitation, habitat degradation, and competition and predation by non-native species has drastically depleted their densities and extirpated many local populations. As a result, shellfish aquaculture production has shifted to the introduced Pacific oyster, Crassostrea gigas. An underlying objective of this dissertation is the use of molecular genetics to improve our ability to accurately identifying optimal oyster broodstock for either restoration of Olympia oysters or farming of Pacific oysters. The ecological benefits provided by oysters as well as the Olympia oyster's historical significance, has motivated numerous restoration/supplementation efforts but these efforts are proceeding without a clear understanding of the genetic structure among extant populations, which could be substantial as a consequence of limited dispersal, local adaptation and/or anthropogenic impacts. To facilitate this understanding, we isolated and characterized 19 polymorphic microsatellites and used 8 of these to study the genetic structure of 2,712 individuals collected from 25 remnant Olympia oyster populations between the northern tip of Vancouver Island BC and Elkhorn Slough CA. Gene flow among geographically separated extant Olympia oyster populations is surprisingly limited for a marine invertebrate species whose free-swimming larvae are capable of planktonic dispersal as long as favorable water conditions exist. We found a significant correlation between geographic and genetic distances supporting the premise that coastal populations are isolated by distance. Genetic structure among remnant populations was not limited to broad geographic regions but was also present at sub-regional scales in both Puget Sound WA and San Francisco Bay CA. Until it can be determined whether genetically differentiated O. lurida populations are locally adapted, restoration projects and resource managers should be cautious of random mixing or transplantation of stocks where gene flow is restricted. As we transition from our Olympia oyster population analysis to our Pacific oyster quantitative analysis, we recognize that traditional quantitative trait locus (QTL) mapping strategies use crosses among inbred lines to create segregating populations. Unfortunately, even low levels of inbreeding in the Pacific oyster (Crassostrea gigas) can substantially depress economically important quantitative traits such as yield and survival, potentially complicating subsequent QTL analyses. To circumvent this problem, we constructed an integrated linkage map for Pacific oysters, consisting of 65 microsatellite (18 of which were previously unmapped) and 212 AFLP markers using a full-sib cross between phenotypically differentiated outbred families. We identified 10 linkage groups (LG1-LG10) spanning 710.48 cM, with an average genomic coverage of 91.39% and an average distance between markers of 2.62 cM. Average marker saturation was 27.7 per linkage group, ranging between 19 (LG9) and 36 markers (LG3). Using this map we identified 12 quantitative trait loci (QTLs) and 5 potential QTLs in the F1 outcross population of 236 full-sib Pacific oysters for four growth-related morphometric measures, including individual wet live weight, shell length, shell width and shell depth measured at four post-fertilization time points: plant-out (average age of 140 days), first year interim (average age of 358 days), second year interim (average age of 644 days) and harvest (average age of 950 days). Mapped QTLs and potential QTLs accounted for an average of 11.2% of the total phenotypic variation and ranged between 2.1 and 33.1%. Although QTL or potential QTL were mapped to all Pacific oyster linkage groups with the exception of LG2, LG8 and LG9, three groups (LG4, LG10 and LG5) were associated with three or more QTL or potential QTL. We conclude that alleles accounting for a significant proportion of the total phenotypic variation for morphometric measures that influence harvest yield remain segregating within the broodstock of West Coast Pacific oyster selective breeding programs. / Graduation date: 2012

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