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Palmer, Shiree. "The ecological role of a common seastar (Patiriella spp.) within intertidal cobble fields : a thesis submitted to the Victoria University of Wellington in partial fulfilment of the requirements for the degree of Master of Science in Marine Biology /". ResearchArchive@Victoria e-Thesis, 2010. http://hdl.handle.net/10063/1240.
Pełny tekst źródłaPalmer, Penny L., i n/a. "The biology of Dendrogaster (Crustacea, Ascothoracida), parasitic in sea stars from Otago, New Zealand". University of Otago. Department of Marine Science, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090731.161951.
Pełny tekst źródłaMartel, André. "Cycle et comportement de reproduction du néogastéropode Buccinum undatum L. dans le golfe Saint-Laurent /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1985. http://theses.uqac.ca.
Pełny tekst źródłaBoivin, Yves. "Le cycle de reproduction d'une étoile de mer couveuse subarctique Leptastérias polaris /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1985. http://theses.uqac.ca.
Pełny tekst źródłaPeters, Kevin J. "The chemical ecology of Antarctic sponges". Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2009p/peters.pdf.
Pełny tekst źródłaAdditional advisors: Bill J. Baker, James B. McClintock, Donald D. Muccio, Robert W. Thacker. Description based on contents viewed June 3, 2009; title from PDF t.p. Includes bibliographical references.
Cambell, Stephen Sean. "Morphology and histochemistry of the extracellular matrix of embryos following freeze substitution of the starfish Pisaster ochraceus". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/28938.
Pełny tekst źródłaMedicine, Faculty of
Graduate
Poorbagher, Hadi, i n/a. "Life-history ecology of two New Zealand echinoderms with planktotrophic larvae". University of Otago. Department of Marine Science, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081029.160011.
Pełny tekst źródłaBOYER, EDWARD HENRI. "THE NATURAL DISAPPEARANCE OF A TOP CARNIVORE AND ITS IMPACT ON AN INTERTIDAL INVERTEBRATE COMMUNITY: THE INTERPLAY OF TEMPERATURE AND PREDATION ON COMMUNITY STRUCTURE (GULF OF CALIFORNIA)". Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184109.
Pełny tekst źródłaŞahin, Özge Turna İsmail İbrahim. "Antalya Körfezi Doğu Kıyıları' nda (Antalya - Gazipaşa) echinodermata faunasının belirlenmesi /". Isparta : SDÜ Fen Bilimleri Enstitüsü, 2008. http://tez.sdu.edu.tr/Tezler/TF01185.pdf.
Pełny tekst źródłaMiller, Bruce Allen 1953. "Larval abundance and early juvenile recruitment of echinoids, asteroids, and holothuroids on the Oregon coast". Thesis, Thesis (M.S.)--University of Oregon, 1995, 1995. http://hdl.handle.net/1794/10056.
Pełny tekst źródłaHarvey, Christian. "Analyse chimique des astérosaponines chez Leptastérias polaris et leur rôle dans la réponse défensive de Buccinum undatum /". Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1985. http://theses.uqac.ca.
Pełny tekst źródłaGarcía, Cisneros Álex. "Estructura, distribución e historia evolutiva de las poblaciones de estrellas de mar Echinaster sepositus y Coscinasterias tenuispina". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/398123.
Pełny tekst źródłaUnderstanding the phylogeography and genetic structure of populations, and the processes associated with their patterns, is important for assessing vulnerability of marine species and developing strategies for their management. Along the Mediterranean Sea, there are 154 echinoderm species, of which 33 are asteroids. However, there are few studies that describe their phylogeographic patterns or genetic structure. We studied two common atlanto-mediterranean species that share part of their distribution along the rocky shores, Echinaster sepositus and Coscinasterias tenuispina. E. sepositus reproduces sexualy and generates lecithotrophic larvae, and C. tenuispina is able to reproduce both sexually (with planctotrophic larvae) and asexually by fission. Here, we analysed the genetic structure and phylogeography of both species by using mitochondrial cytochrome c oxidase subunit I gene (COI) and nuclear microsatellite loci, previously described using 454 pyrosequencing genome libraries. Furthermore, we studied the reproductive cycle and population dynamics of a monoclonal population of C. tenuispina. Finally, we studied the telomere length, as a molecular marker of senescence, in different populations of C. tenuispina and different tissues from different parts of the same individuals. Our results reveal a low genetic diversity in both species, lower than other echinoderms with the same distribution range. However, the reasons differ depending on the species. Low diversity in E. sepositus can be explained by a recent demographic expansion from few individuals with few alleles, while in C. tenuispina by the presence of asexual reproduction processes along all its distribution range, even with totally monoclonal populations. Marine barriers, like Almeria-Oran front or Siculo-Tunisian strait, limit the gene flow through populations, although allow certain permeability in both starfish. In areas located near the distribution edges of C. tenuispina, increases the asexuality rates, and fission processes are maintained over time. Events of fissiparity also increase with environmental instability, by both thermal and physical factors. However, well-fed individuals do not lose their potential for sexual reproduction (development of gonads, only males), even the absence of sexuality in many generations. Finally, C. tenuispina presents at least one mechanism to avoid or postpone senescence and ensure persistence of clonal populations: telomere elongation.
Potton, Derrick John. "Neurohormonal control of feeding in the starfish". Thesis, Royal Holloway, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267555.
Pełny tekst źródłaDean, Juliette. "Evolutionary diversification of asteroids and ophiuroids [Echinodermata]". Thesis, University of Cambridge, 1999. https://www.repository.cam.ac.uk/handle/1810/251696.
Pełny tekst źródłaBaeta, Alacio Marc. "Ecology of some keystone invertebrates inhabiting shallow soft bottom communities of the Maresme coast (NW Mediterranean Sea)". Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/295965.
Pełny tekst źródłaEls bivalves que viuen en grans agregacions d'individus, com ara algunes espècies de musclos, cloïsses i escopinyes; i alguns predadors que ocupen elevats nivells tròfics com ara les estrelles de mar juguen un paper fonamental en l'estructura, integritat, estabilitat i diversitat de les comunitats biològiques, sent habitualment considerats com espècies clau. La seva desaparició o declivi pot conduir a efectes desproporcionats sobre el conjunt de les comunitats on habiten, fins i tot afectant la supervivència d'altres espècies. Tot i que les espècies clau són essencials per mantenir la biodiversitat al planeta Terra, sovint no s'ha prestat prou atenció al seu estudi. El principal objectiu d'aquesta Tesi Doctoral ha estat l'estudi de l'ecologia d’algunes d’aquestes espècies clau que habiten els fons tous poc profunds de la costa del Maresme (nord-oest del Mar Mediterrani). Els resultats obtinguts milloren de manera significativa el coneixement de la població de petxinot de sang (Callista chione) i dels seus potencials depredadors, diferents espècies d'estrelles de mar (Astropecten spp.) que cohabiten a la zona. Al mateix temps ajuden a entendre les seves relacions tròfiques, l'estat de les seves poblacions i es proposen pautes per a la seva conservació. La costa del Maresme és molt propera a la ciutat Barcelona, i per això ha concentrat històricament una elevada pressió antropogènica que ha modificat i alterat el seu medi ambient. Els resultats d'aquesta Tesi Doctoral mostren com l'estat crític de la població de petxinot de sang (C. chione) és conseqüència de la combinació de diferents pressions antropogèniques: dragatges de sorres i la pesca de bivalves amb dragues. També s'ha observat que aquestes mateixes pressions han produït canvis significatius en les poblacions d'estrelles de mar Astropecten. A. aranciacus ha resultat ser l'estrella més vulnerable a aquestes pressions i en conseqüència ha estat la més afectada, veient-se la seva població disminuir a un ritme preocupant. A més, s'ha descrit per primera vegada la reproducció, el creixement i la segregació batimètrica per mida de A aranciacus. Els resultats obtinguts també mostren que les diferents espècies de Astropecten poden cohabitar per la segregació dels seus nínxols ecològics permeten-los no competir pels recursos disponibles (preses i hàbitat). Aquesta Tesi Doctoral pretén proporcionar un rerefons valuós per a millorar la conservació d'aquestes espècies clau, així com promoure l'explotació sostenible dels mol·luscs bivalves.
Los bivalvos que viven en grandes agregaciones de individuos, como por ejemplo algunas especies de mejillones, almejas y berberechos; y algunos predadores que ocupan elevados niveles tróficos como por ejemplo las estrellas de mar juegan un papel crucial en la estructura, integridad, estabilidad y diversidad de la comunidades biológicas, siendo habitualmente considerados como especies clave. Su desaparición o declive puede conducir a efectos desproporcionados sobre el conjunto de sus comunidades, incluso afectando la supervivencia de otras especies. Aunque las especies clave son esenciales para mantener la biodiversidad en el planeta Tierra, a menudo no se ha prestado suficiente atención a su estudio. El principal objetivo de esta Tesis Doctoral fue el estudio de la ecología de algunas especies clave que habitan los fondos blandos y someros de la costa del Maresme (noroeste del Mar Mediterráneo). Los resultados obtenidos mejoran de forma significativa el conocimiento sobre la concha fina (Callista chione) y sus depredadores potenciales, distintas species de estrellas de mar del género Astropecten que cohabitan en la zona. Al mismo tiempo ayudan a entender sus relaciones tróficas, el estado de sus poblaciones y se proponen pautas para mejorar su conservación. La costa del Maresme se halla cerca de la ciudad Barcelona, y por ello ha concentrado históricamente una elevada presión antropogénica que ha modificado y alterado su medio ambiente. Los resultados de esta Tesis Doctoral muestran como el estado crítico de la población de concha fina (C. chione) es consecuencia de la combinación de distintas presiones antrópogenicas: dragados de arenas y pesquerías de moluscos bivalvos. También se ha observado que estas mismas presiones han producido cambios significativos en las poblaciones de estrellas de mar Astropecten. A. aranciacus ha resultado ser la estrella más vulnerable a dichas presiones y en consecuencia ha sido la más afectada, viéndose su población disminuir a un rito preocupante. Además, se ha descrito por primera vez la reproducción, el crecimiento y la segregación batimétrica por tallas de A. aranciacus. Los resultados documentados también muestran que las distintas especies de Astropecten pueden cohabitar por la segregación de sus nichos ecológicos permitíendoles no competir por los recursos disponibles (presas y hábitat). Esta Tesis Doctoral pretende proporcionar un trasfondo valioso para mejorar la conservación de estas especies clave, así como promover la explotación sostenible de los moluscos bivalvos.
Tsow, Alexander W. "Starfish a table-centric tool for design derivation /". [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3277963.
Pełny tekst źródłaSource: Dissertation Abstracts International, Volume: 68-09, Section: B, page: 6092. Adviser: Steven D. Johnson. Title from dissertation home page (viewed May 8, 2008).
Vogler, Catherine. "Phylogeography and evolution of the crown-of-thorns starfish Acanthaster planci". Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-133642.
Pełny tekst źródłaYun, Sang Seon. "Biochemical, molecular and pharmacological characterisation of SALMFamide neuropeptides from the starfish Marthasterias glacialis". Thesis, Royal Holloway, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313518.
Pełny tekst źródłaDeaker, Dione. "Resilience of juvenile crown of thorns starfish and the implications for population outbreaks". Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/28204.
Pełny tekst źródłaCha, Mei-wah. "The ecology of tapes philippinarum (Bivalvia: Veneridae) in Starfish Bay, Hong Kong, and its potential as a biological indicator of coastal pollution /". [Hong Kong : University of Hong Kong], 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13762370.
Pełny tekst źródłaPuppo, Studer Agostina Margarita. ""Modulation of calcium signalling by F-actin during maturation and fertilization of starfish oocytes"". Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520773.
Pełny tekst źródłaBurdyniuk, Mariia [Verfasser], i Alexander [Akademischer Betreuer] Aulehla. "Actin synchronizes chromosome capture by microtubules in starfish oocyte meiosis / Mariia Burdyniuk ; Betreuer: Alexander Aulehla". Heidelberg : Universitätsbibliothek Heidelberg, 2018. http://d-nb.info/1177251493/34.
Pełny tekst źródłaVogler, Catherine [Verfasser], i Gert [Akademischer Betreuer] Wörheide. "Phylogeography and evolution of the crown-of-thorns starfish Acanthaster planci / Catherine Vogler. Betreuer: Gert Wörheide". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2010. http://d-nb.info/1015170579/34.
Pełny tekst źródłaBischof, Johanna [Verfasser], i Alexander [Akademischer Betreuer] Aulehla. "The molecular mechanism of surface contraction waves in the starfish oocyte / Johanna Bischof ; Betreuer: Alexander Aulehla". Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180616111/34.
Pełny tekst źródłaHannah, Lucie C. "Maturation promoting factor (MPF) in relation to the fertilization and early development of lugworm and starfish oocytes". Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423995.
Pełny tekst źródłaLim, Dmitri. "Ca²⺠signals induced by InsP₃ and NAADP during maturation and fertilization of starfish oocytes". Thesis, Open University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397915.
Pełny tekst źródłaLin, Ming. "Identification and functional characterization of relaxin-type and pedal peptide/orcokinin-type neuropeptides in the starfish Asterias rubens". Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/30715.
Pełny tekst źródłaCha, Mei-wah, i 車美華. "The ecology of tapes philippinarum (Bivalvia: Veneridae) in Starfish Bay, Hong Kong, and its potential as a biological indicator of coastalpollution". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31233442.
Pełny tekst źródłaCarver, Leland Joseph. "A Clockwork Orange: Student Advising and Technology". Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou159621692037443.
Pełny tekst źródłaRahman, Ridzwan Abdul. "Recovery processes of coral communities following the crown-of-thorns starfish, Acanthaster planci, infestations on the east coast islands of peninsular Malaysia". Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283767.
Pełny tekst źródłaReimer, Corinne L. "The distribution of glycoconjugates in the basal lamina and ECM during esophageal muscle formation in embryos of the starfish Pisaster ochraceus as revealed by lectin hsitochemistry". Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/27626.
Pełny tekst źródłaMedicine, Faculty of
Graduate
Lafontaine, Tania. "Ecocriticism and Science Fiction Theory: the Role of Environments and Representations of Post-Nature in Starfish, Maelstrom and Behemoth by Peter Watts and The Road by Cormac McCarthy". Mémoire, Université de Sherbrooke, 2014. http://savoirs.usherbrooke.ca/handle/11143/77.
Pełny tekst źródłaNance, David. "Settlement of the scallops Pecten maximus (L.) and Aequipecten opercularis (L.) and their predators : the starfish Asterias rubens L. and the crabs Necora puber (L.) and the Cancer pagurus L. on the west coast of Scotland". Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=124328.
Pełny tekst źródłaZhuang, Zhenpeng. "Comparative Physiology of Calcium Transport in Crustacean (Homarus Americanus) and Echinoderm (Helianthoides Pycnopodia) Gastrointestinal Epithelia". Thesis, 1996. http://hdl.handle.net/10125/10564.
Pełny tekst źródłaNavarrete, Sergio A. "Effects of interactions between predators, variable predation regimes, and species body size on rocky intertidal communities : comparative and experimental approaches /". 1994. http://hdl.handle.net/1957/14234.
Pełny tekst źródłaOliveira, Bárbara Xavier Louro de. "Dynamics of circulating coelomocytes during starfish regeneration". Master's thesis, 2016. http://hdl.handle.net/10451/25862.
Pełny tekst źródłaA regeneração é um fenómeno regulado com implicações biológicas variadas. No Reino Animal, há diversos exemplos deste processo que envolvem a reparação de tecidos, órgãos e membros. No entanto, a regeneração nos vertebrados é limitada na medida em que não se observa a regeneração completa de todos os órgãos. Nos invertebrados, existe uma maior flexibilidade em termos de reparação e até mesmo de substituição de tecidos e/ou órgãos. Após predação ou autotomia, alguns animais são capazes de substituir o órgão ou a porção perdida e muitas vezes esta pode levar uma vida autónoma podendo ela própria regenerar e até formar um individuo completo, dependendo sempre da perda, mas também da capacidade de regeneração do organismo. Este fenómeno acaba por se sobrepor nos invertebrados com a reprodução assexuada. Muitos equinodermes têm uma capacidade regenerativa elevada que se mantém ao longo de toda a sua vida, incluindo na fase adulta. A primeira resposta na regeneração é o fecho das feridas pelas contrações musculares e a formação de agregados de celómocitos, as células circulantes do fluído celómico que banha toda a cavidade interna dos equinodermes. Estas células têm um papel reconhecido na primeira linha de defesa do sistema imunitário que inclui várias funções, como coagulação e defesa contra organismos patogénicos por fagocitose. Os equinodermes têm uma grande proximidade filogenética com os cordados. Contudo o estudo destes organismos ao nível molecular não é muito frequente. Devido à pouca informação relativamente ao seu genoma, transcriptoma, proteoma ou metaboloma e por haver outros organismos com mais informação reportada, estes facilitam as comparações extrapoladas com cordados. Embora o ouriço do mar Strongylcentrotus purpuratus seja o único equinoderme a ter o genoma sequenciado e anotado, e consequentemente vários estudos moleculares tenham sido possíveis, estes organismos têm a menor capacidade de regeneração observada entre as diferentes classes de equinodermes, tendo sido muito reduzida a sua contribuição para o estudo da regeneração. Para uma maior compreensão dos coelomócitos, este trabalho apresenta a caracterização das populações celulares e a sua variância percentual durante o processo de regeneração. Embora a classe Asteroidea não tenha sido utilizada extensamente, os organismos desta são uma excelente escolha para o estudo do processo da regeneração. Marthasterias glacialis L. é uma estrela do mar espinhosa, betónica que pode ser encontrada ao longo de toda a costa oeste portuguesa capaz de viver a vários níveis de profundidade (0–200m), podendo atingir até 70 centímetros de diâmetro e com capacidade de regenerar todas as partes do corpo (internas e externas), incluindo o sistema nervoso central. Devido ao facto de haver pouca informação relativa aos equinodermes e mais especificamente às estrelas do mar, é por vezes difícil encontrar correlações na literatura com o estudo aqui apresentado. Efetuar analogias com outras classes de equinodermes é também desafiante, devido às diferenças inter-espécie, na metodologia escolhida para o estudo das células (diferentes tipos de microscopia) ou até no manuseamento dos celomócitos (células vivas ou fixadas, ex vivo ou em cultura). Desta forma, a primeira fase deste estudo foi dedicada à caracterização das populações celulares do fluído celómico através da citometria de fluxo e por microscopia de fluorescência. De forma a prosseguir com a caracterização do fluído celómico, algumas etapas de otimização tiveram de ser efetuadas para que o manuseamento das células ex vivo se fizesse sem comprometer o estudo ou os seus objetivos. Estas otimizações foram feitas ao nível das condições que reduzissem a agregação dos celomócitos após recolha do fluído celómico com o uso de diferentes tampões anticoagulantes, de diferentes condições de centrifugação, de diversas concentrações de corantes para que a análise de diferentes estudos (viabilidade celular e ciclo celular) fosse possível. Iii O desafio da optimização do ensaio de viabilidade celular centrou-se na escolha de dois corantes compatíveis, ou seja, que apresentassem comprimentos de onda de emissão e locais de ligação ao DNA distintos para que a análise fosse mais fiável. Duas populações celulares no fluído celómico (aqui designadas como P3 e P5) foram distinguidas através da citometria de fluxo e analisadas individualmente em termos de abundância no fluído celómico, morfologia, viabilidade celular e ciclo celular. A células da população P3 são as menos abundantes no fluído celómico, têm uma forma arredondada com um diâmetro nunca superior a 4 μm. Quanto à sua caracterização ao nível da viabilidade celular estas incorporam os diferentes corantes de exclusão de viabilidade celular após a recolha do fluído celómico, indicando uma baixa ou até nenhuma viabilidade celular. A população celular P5, que é regularmente 4 vezes mais numerosa que a população P3, apresenta várias morfologias, dependendo da concentração salina do meio ou do substrato que contactam, assim o seu tamanho varia entre 7 μm a 23 μm. Estas têm uma alta viabilidade celular no momento em que abandonam o organismo, observada pela não incorporação dos corantes de exclusão. A sua viabilidade vai diminuindo ao longo do dia da experiência mesmo em condições de escuridão e baixa temperatura (4ºC). As diferentes fases do ciclo celular variam na quantidade de DNA em cada célula (a fase G2M tem o dobro do conteúdo de DNA da fase G0G1). Para o estudo do ciclo celular, a concentração do corante (iodeto de propídeo) tem de ser saturante para que se possa inferir em que fase do ciclo as células se encontram. Para as células P3 não foi possível detectar eventos para todas as fases do ciclo celular, podendo ser devido à falta de viabilidade que apresentam, tendo uma atividade metabólica ou mitótica reduzida. As células P5 apresentam um ciclo celular bem definido, no qual a maioria das células se encontra na primeira fase do mesmo. Devido ao aparecimento de gâmetas masculinos, em algumas amostras de fluído celómico, a sua caracterização morfológica e análise citométrica foi também possível. Os estudos feitos até ao momento envolvendo celomócitos da espécie M. glacialis centraram-se na caracterização do seu proteoma total, sem separação das diferentes populações, e na proteómica diferencial nas diferentes fases da regeneração. Para isso a caracterização do proteoma de cada população, isolada por citometria de fluxo seria o próximo passo. Contudo houve algumas dificuldades na recuperação das células após a sua separação por citometria de fluxo. Sendo este processo provavelmente violento física e osmoticamente para as células. A reprodutibilidade da técnica para estes tipos celulares foi muito baixa, devido à disparidade dos resultados nos diferentes ensaios. O estudo da proteómica diferencial foi feito para pontos temporais que cobrissem as diferentes fases da regeneração (48 horas, 13 dias e 10 semanas). A maioria dos estudos feitos em celomócitos durante a regeneração sugere que o seu papel é mais determinante na primeira fase do processo regenerativo – cicatrização. Assim optou-se pelo estudo dos celomócitos durante o primeiro dia de regeneração. Algumas diferenças estatisticamente significativas foram observadas nas percentagens de células P5 nas primeiras horas (2, 8 e 24 horas) após amputação comparando com os valores relativos a um grupo controlo. Antes da indução da regeneração (t=0), a população P5 no grupo de animais posteriormente amputados apresenta uma média de valores percentuais superior à do grupo controlo. Após indução da regeneração, as proporções da população P5 diminuem significativamente. Os principais fatores a contribuírem para esta perda de células será a perda de fluido celómico através das feridas e o seu recrutamento para o processo de coagulação. A variação da proporção da população P3 ao longo do tempo mostrou ser independente do processo de regeneração. Os gâmetas masculinos apareceram durante o estudo dos celomócitos na regeneração apenas nos indivíduos que foram amputados. A caracterização das populações de celomócitos apresentada nesta dissertação constitui um contributo para o conhecimento das funções fisiológicas dos celomócitos circulantes desta espécie de equinoderme.
Regeneration is a phenomenon that occurs throughout the Animal Kingdom and it has wide biological implications. Echinoderms have an outstanding regeneration ability that allows the replacement and regrowth of lost organs or body parts due to injury caused by autotomy or predation. The first response in the regeneration process is to close all the wounds with muscle contraction and coelomocytes clots. Coelomocytes are free circulating cells in coelomic fluid, which fills the internal cavity of echinoderms. These cells are known to have a role in the first defence by the immune system, with different functions as clotting, and defence against pathogens such as phagocytosis. Starfishes are excellent organisms to explore organ and tissue regeneration. Marthasterias glacialis L. belongs to Asteroidea class and it has whole body regeneration ability, including the central nervous system. Due to a lack of knowledge, it is difficult to find information about coelomocytes characteristics or to compare it with other classes of echinoderms, due to interspecies variability and to the diverse methodical approaches used in the several published studies. Thus the first part of this study was to characterize different coelomocytes population through flow cytometry and fluorescence microscopy. In order to perform coelomic fluid cells characterization, several optimization steps had to be done so as to know how to handle these cells ex vivo. Two different populations (here named P3 and P5) were found among coelomocytes and they were studied individually in terms of abundance, morphology, cell viability and cell cycle. P5 showed to have morphological similarities with phagocytes population whereas P3 cell populations seemed to have low metabolic or mitotic activity. Due to male gametes appearance in coelomic fluid samples, its characterization through flow cytometry was possible. Coelomocytes dynamics during regeneration was also assessed during the first day after amputation. There were a few statistically significant differences only in P5 cell population percentage in the first hours (2h, 8h and 24h) after amputation when compared with values for non-amputated animals. The work presented in this dissertation will hopefully contribute to an increase on the available cellular and molecular knowledge about circulating coelomocytes in M. glacialis.
Pinto, Joana Borrego. "The Mechanism of Centriole Inactivation in Starfish Oocytes". Doctoral thesis, 2015. http://hdl.handle.net/10362/17416.
Pełny tekst źródłaZeng, Jyun-Ze, i 曾鈞澤. "Study of Starfish Instruction Set Usage for H.264". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10469655682258980566.
Pełny tekst źródła國立清華大學
資訊工程學系
96
As the multimedia technology development, there are more and more video/audio standards. In order to encode or decode different video/audio standards in one system, DSP (Digital Signal Processor) is a good choice to do video/audio process. The speed of DSP is influenced much by the hardware architecture and the efficiency of compiling instructions, and both of them are decided when defining instruction set. In this paper, we profile the instruction usage with different compilers to analyze why some instructions are nearly used in H.264. We use the instruction set and compilers of Starfish DSP, which is developed by TsingHua University and ChiaoTung University to do our experiment.
CHU, SHIH-CHIEN, i 朱詩倩. "A Creative Discourse on the Documentary Film Starfish Girl". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/7nc35m.
Pełny tekst źródła國立臺灣藝術大學
電影學系
106
‘I can’t be with you all your life. But I love you with all my life.’ She said. It is hoped that through Starfish Girl, we would get to see the beautiful experiences and the value of life of a unique individual. One should never be labelled, as the labels tend to blur one’s true nature. Gradually stripping off the labels attached to the protagonist, Starfish Girl shows the audience the process of understanding a person from a fresh point of view. Every creation is a result of a journey of awakening in mind and body. The story of a family is often incomprehensible to the others. Starfish Girl also reflects the author’s mind, and by exchanging the inner characters with the protagonist, the author reveals more secrets hidden deep in their hearts. The director has no intention to conceal her intimate interaction with the protagonist as they both appear in this realist film as participants as well as observers. It reveals the life of a highly sensitive person and how a girl, who was forced to be socialised, try to not only understand but also live in harmony with herself. Moreover, by comparing it with two more widely known documentaries, I Love 080 by Yang Li-chou and Small Talk by Huang Hui-chen, we get to see the intricate and complicate relationships disclosed in the films. Furthermore, the author looks into the cases, in which the filmmakers’ self-awareness is influenced and changed by the reality as well as the protagonists’ frankness revealed in the films during her years’ experience in documentary production. Starfish Girl is a 20-minute participatory documentary shot in full HD. It was premiered at the 2017 Taipei Golden Horse Film Festival and was selected as the opening film of the 2017 Formosa Festival of International Filmmaker Awards. Furthermore, it will be screened at various international film festivals and social welfare organisations.
Rivera, Posada Jairo A. "Pathogenesis of crown-of-thorns starfish (Acanthaster planci L)". Thesis, 2012. https://researchonline.jcu.edu.au/23660/1/01front.pdf.
Pełny tekst źródłaWen-Li, Tang. "A Fast, and Flexible Simulation Framework for Starfish DSP Architecture". 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0016-1303200709292475.
Pełny tekst źródłaMarques, Vera Cristina J. "Impact of seawater acidification in starfish regeneration: a proteomic approach". Master's thesis, 2015. http://hdl.handle.net/10451/22554.
Pełny tekst źródłaSince the start of the industrial revolution (XVIII century), atmospheric levels of carbon dioxide (CO2) have been rising at a far greater rate than previously experienced, increasing CO2 dissolved in seawater. This process is recognized as ocean acidification and can severely damage calcifying organisms. Since echinoderms have an endoskeleton composed of magnesium calcite, they are predicted to be a sensitive taxa affected by this acidic environment. Taking into account that some species of this filo have a faster regeneration capacity under low pH, analysis of the proteome represents a powerful tool to examine these physiological trait at a molecular level. Trying to strengthen this work on ocean acidification effects, we studied Asterias rubens’ behaviour by observing their preference in choosing a leading arm when submitted to different regeneration time-points (non-regeneration and regeneration after 1, 4, 9 and 14 days) and at two pH environments (control (CpH) – 8.1 and low (LpH) – 7.7). It was concluded that they do not have a preference leading arm before ablation in both pH environments. Although, one day after ablation they drastically decrease the use of the wounded arms, as expected, while the non-amputated arms did not suffer any changes. Furthermore, after nine days subjected to these conditions, it seems that sea stars recovered completely the movement of the amputated arms. Asterosaponins search was also a vital part of this work, since they are known for having important functions in sea stars. We observed that two of the nine asterosaponins detected in the control pH were also detected in low pH samples, and that their concentration decreased, suggesting that acidic pH may alter their biosynthesis. Proteins from both cell-free coelomic fluid (CFF) and radial nerve cord (RNC) were extracted, digested and further analyzed by nano LC-MS/MS. We were able to identify 298 proteins, being 81% of all proteins identified differentially expressed. A surprising finding was the almost absence of stress proteins in an acidic pH environment. In this work, we propose a correlation between an acidic environment and asterosaponins’ biological effects. The decline in diversity and amount of these biomolecules can be caused by already known decreases in respiratory rate and cholesterol absorption. Although, asterosaponins might have positive effects in predation and reproduction. The detected increase in vitellogenin expression seems to be associated with the amplified spawning event induced by the low levels of asterosaponins at acidic pH, thereby also enhancing reproduction.
Desde o início da revolução industrial (século 18) que os níveis atmosféricos de dióxido de carbono (CO2) têm aumentado a um ritmo nunca antes registado (de 280ppm para 380ppm, e espera-se que duplique no final do século), essencialmente devido à emissão de gases com efeito de estufa resultantes de atividades humanas. Como consequência, a concentração de CO2 dissolvido nos oceanos também aumenta, e por sua vez, também a concentração de iões hidrogénio e iões bicarbonato, conduzindo a uma diminuição de pH e de iões carbonato. Este conjunto de reações é designado por acidificação dos oceanos, e pode danificar seriamente o funcionamento de organismos marinhos que de alguma forma utilizam o processo de biocalcificação na sua estrutura corporal. Os equinodermes possuem um endosqueleto composto por calcite de magnésio, têm uma extraordinária capacidade de regeneração, mas também são osmoconformadores. Isto significa que o fluido celómico (CF) que preenche a cavidade corporal é muito semelhante, a nível de composição iónica, ao ambiente externo a que está submetido. Embora também muito idêntico, o pH do fluido celómico é geralmente 0.11-0.58 unidades mais baixo que o pH do exterior, devido a taxas de difusão de CO2 mais ou menos lentas, que podem aumentar ou reduzir a concentração de dióxido de carbono no CF, respetivamente. Por estas razões prevê-se que os equinodermes sejam um taxa sensível a ambientes ácidos. Apesar de se esperar que todas as espécies sejam afetadas de forma negativa, é do conhecimento científico que algumas espécies deste filo crescem e desenvolvem-se mais depressa quando expostas a pH ácido, enquanto outras apresentam diminuição de metabolismo ou redução da expressão proteica global. Considerando a diversidade incongruente de resultados publicados, e tendo a estrela-do-mar comum A. rubens como espécie-alvo, realizámos análises de expressão proteica para estudar estas observações fisiológicas de uma perspetiva molecular. Por forma a ter um estudo mais completo sobre o efeito da acidificação nesta espécie, observámos estrelas-do-mar sob diferentes tempos de regeneração (não-amputação e amputação após 1 dia, 4, 9 e 14) submetidas a dois pHs (controlo (CpH) – 8.1 e ácido (LpH) – 7.7), com o propósito de determinar com que braço preferencialmente elas iniciavam a deslocação. Os braços escolhidos para amputação foram os mais próximos à madreporita. As estrelas-do-mar não apresentaram preferência no braço ‘líder’ antes de amputadas e sob CpH, o que não é consistente com resultados já publicados. No entanto, como esperado, os braços amputados apresentaram uma diminuição do número de movimentos um dia após a regeneração ser imposta, enquanto o número de movimentos dos braços não-amputados permaneceu igual. Após nove dias os movimentos dos braços amputados foram restabelecidos para os valores iniciais (sem amputação), e por isso considerámos que as estrelas recuperaram o movimento normal dos braços. É vantajoso para a estrela-do-mar que este movimento seja restabelecido o mais rapidamente possível, para que possa, entre outros, alimentar-se e/ou fugir de possíveis predadores. Para estudar os fatores moleculares que possam estar envolvidos em resposta a uma futura diminuição do pH dos oceanos, foram recolhidos dois tipos de amostra: fluido celómico (dois pHs e 15 dias pós-amputação), e nervo radial (RNC; dois pHs e não-amputação; dois pHs e 15 dias pós-amputação). O CF foi centrifugado para que fossem retirados os coelomócitos, designando-se desta forma fluido celómico livre de células (CFF). Este fluido foi submetido a centrifugação e ultrafiltração para separar a fração de alta massa molecular (proteínas) da fração de baixa massa molecular. Esta última contém asterosaponinas, moléculas que são conhecidas por terem funções importantes a nível de sinalização química mas também a nível digestivo e reprodutivo, e que por isso considerámos essenciais neste estudo. Esta fração foi então sujeita a extração de fase sólida (SPE) com diferentes eluições de acetonitrilo e ácido fórmico para isolamento das asterosaponinas, e posteriormente analisadas por ESI-MS. Os dados foram adquiridos por um espectrofotómetro linear ion trap mass Thermo Finnigan LTQ, controlado pelo software Xcalibur v 2.0, também usado na análise dos espectros resultantes da leitura das amostras. Todas as asterosaponinas investigadas estavam presentes no pH controlo, mas apenas duas delas foram detetadas em estrelas-do-mar submetidas a pH ácido. Para além disto, as suas concentrações diminuíram em pH ácido. Tendo em conta que a A. rubens apresenta um baixa taxa de respiração após 27 dias exposta a pH 7.7 do que quando submetida a pH 8.1, podemos assumir que este decréscimo irá alterar a disponibilidade de ATP, e consequentemente comprometer a biossíntese de asterosaponinas. Por sua vez, a diminuição destas biomoléculas poderá ter efeitos negativos a nível digestivo, através da redução da absorção de colesterol, mas poderá também ter efeitos positivos ao nível da predação. As proteínas do CFF foram extraídas e precipitadas com recurso a ácido tricloroacético e beta-mercaptoetanol, enquanto as proteínas do RNC foram extraídas e precipitadas recorrendo a azoto líquido e a um buffer suplementado com SDS, Tris-HCl, DTT, um cocktail anti-protease e PMSF. A quantificação das proteínas do CFF e RNC foi feita com recurso ao QuantiPro BCA Assay KIT 0.5-30μg/mL protein, e a digestão, embora diferente, teve como base o uso de redutores de pontes persulfureto (DTT e TCEP), iodoacetamida para alquilação das cisteínas e tripsina para quebrar a proteína em péptidos. As amostras digeridas de ambos os tecidos foram analisadas por nano LC-MS/MS. Foram identificadas 213 proteínas no RNC, mas apenas uma estava presente em todas as condições estudadas. Por esta razão, podemos concluir que o procedimento experimental deve ser otimizado. A análise do CFF permitiu identificar 298 proteínas, das quais 19% eram comuns às duas condições de pH. De acordo com estes resultados, 81% de todas as proteínas identificadas estavam diferencialmente expressas. Comuns a ambas as condições de pH, e como esperado, foram detetadas actinas, tubulinas e ubiquitinas. A quantificação realizada permitiu observar um aumento de expressão significativo apenas em 2 proteínas no pH ácido: alfa-tubulina e vitellogenina 1. A primeira está envolvida na formação do citoesqueleto, e por isso, será importante numa fase de rápida proliferação celular. A segunda proteína é responsável pelo transporte de lípidos para os oócitos, e o seu aumento de expressão parece aumentar o número de eventos de desova em estrelas-do-mar. Os baixos níveis de asterosaponinas presentes em pH ácido também parecem favorecer este acontecimento, aumentando desta forma, o sucesso reprodutivo. Com base em estudos recentes realizados em corais e em zooplâncton, previa-se um aumento na expressão de proteínas de stress em condições de pH ácido. No entanto, no presente estudo, as estrelas-do-mar submetidas a esta condição de pH, exibiram apenas uma proteína de stress. Para melhor compreensão dos efeitos da acidificação dos oceanos em cada uma das proteínas aqui identificas, será necessário realizar estudos mais detalhados para avaliar o impacto biológico da expressão proteica diferencial que observámos.
Keesing, John Kenneth. "Feeding biology of the crown-of-thorns starfish, Acanthaster planci (Linnaeus)". Thesis, 1990. https://researchonline.jcu.edu.au/24112/1/01front.pdf.
Pełny tekst źródłaLin, Shin-Jung, i 林欣榮. "Studies on Toxins and Their Sources of Torafugu, Ggoby and Starfish in Taiwan". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/15853684082864384826.
Pełny tekst źródła國立海洋大學
食品科學系
87
ABSTRACT In the recent decade, food poisoning incidents due to marine toxins such as tetrodotoxin (TTX) and paralytic shellfish poison (PSP) were sporadically occurred in Taiwan. The causative fish and shellfish of these food poisoning incidents were mainly puffer fish, followed by purple clam, gastropod Nassariidae and goby fish. In order to have a clearly understanding of the toxicity, toxin and toxin source of those toxic fish and shellfish, the toxicological studies of cultured puffer Takifugu rubripes, goby fish and starfish Astropecten scoparius, the possible prey of toxic gastropods, have been undertaken. To monitor toxicity of cultured puffer, T. rubripes specimens were monthly collected from two aquacultural farms in Ilan County and one farm in Taipei County from November 1996 to October 1997. These specimens were dissected into various parts, and their toxicity was determined by the standard tetrodotoxin bioassay. All specimens collected from Ilan County were non-toxic (<10 MU/g), while the specimens collected from Taipei County during the period from January to March 1997 showed certain toxicity in the ovary and liver. The toxicity was as follows: 105 ± 9 (mean ± S.E.) MU/g ovary and 13 ± 3 MU/g liver in January, 88 ± 12 MU/g ovary in February, and 253 ± 55 MU/g ovary and 17 ± 6 MU/g liver in March. The highest toxicity in ovary and liver was 624 MU/g and 119 MU/g, respectively. Further, among ten specimens of the flatworm Stylochus orientalis collected from the Taipei''s farm in February 1997, four worms showed a low toxicity (1-3 MU/specimen). Flatworms contained TTX-related substances as analyzed by HPLC and GC-MS. In the same period of time, the microflora of the digestive gland in the puffer, aquacultural water and sediment were examined. The results showed that the predominant genus was Vibrio and comprised 37-65% and 40-65% of the microflora incubated aerobically and facultative anaerobically, respectively. Furthermore, HPLC and GC-MS analyses demonstrated that some of the bacteria isolated, such as Aeromonas sp., Pseudomonas vesicularis, V. alginolyticus, V. parahaemolyticus and Vibrio sp. produced TTX and/or its related substances. On the other hand, two paralytic food poisoning incidents due to ingestion of two kinds of fishes included goby Yongeichthys nebulosus and Sillago japonica occurred in Kaohsiung Prefecture in February 1997 and Kaohsiung City in March 1998. After TTX bioassay, the causative fish was identified as Y. nebulosus. The toxicity of retained goby specimens ranged from 2,860-7,650 and 276-950 mouse units (MU), respectively. The toxins were partially purified from the methanolic extracts of toxic fishes by ultrafiltration and Bio-Gel P-2 column chromatography. Cellulose acetate membrane electrophoresis and high performance liquid chromatography analyses demonstrated that the compositions of toxins were tetrodotoxin and anhydrotetrodotoxin. These results indicated that goby fishes inhabited in the estuaries and the downstream portions of rivers and the coast area in Taiwan might contain toxins and cause food poisoning. At the same time, the intensive investigation of toxic goby was also performed from August 1996 to July 1998. More than 300 specimens of twelve species of goby were collected from fifteen locations and examined for toxicity. The specimens of three goby Y. nebulosus, Prachaeturichtys palynema and Radigobius caninus collected from Pingtung, Penghu, Kaohsiung, Miaoli, and Hsinchu were found to contain toxins. The most toxic goby was Y. nebulosus, and its frequency of being found toxic was 93%. Specimens collected from Pingtung Prefecture were most toxic, the toxicity was over 1,000 MU/specimen. The seasonal variation of toxicity in Y. nebulosus was found that the highest toxicity was in winter with the value of 4,998 MU/specimen. The toxin was partially purified from methanolic extract of each toxic goby species by Diaflo YM-1 membrane ultrafiltration and Bio-Gel P-2 column chromatography. HPLC and electrophoresis analyses indicated that each toxin was composed of tetrodotoxin and anhydrotetrodotoxin. In order to elucidate relationship between the toxicity and microflora of the intestine in the goby and environmental materials, the goby Y. nebulosus specimens, seawater and sediment were collected from Penghu Prefecture in September 1998 to assay the aerobic microflora in intestines and environmental materials. The results showed that the predominant genus of goby intestines was Vibrio comprising 46% of the microflora, with V. alginolyticus as the major isolate. The predominant genus in seawater was Pasteurella that comprised 47% of the microflora. Moreover, the predominant genera of sediment were Flavobacterium and other unidentified bacteria that comprised 51% of the microflora. Furthermore, HPLC, UV and GC-MS analyses demonstrated that some isolated bacteria, such as Aeromonas sp., Pseudomonas sp. and V. alginolyticus, could produce TTX and/or its related substances. As known, same gastropods inhabiting in the coastal waters in Pingtung Prefecture were found to contain TTX and paralytic shellfish poison (PSP). To elucidate the food chain of TTX and PSP in these toxic gastropods, the toxicity of marine animals inhabiting in the coastal waters of southern Taiwan was examined. It was first found that a starfish Astropecten scoparius showed lethal potency. Hence, paralytic toxicity was seasonally detected in every 10 specimens of the starfish A. scoparius from Pingtung in Taiwan from January 1996 to December 1997. The highest toxicity of specimen collected in 1996, expressed as TTX, was 5,938 MU. The average toxicity of these specimens was 1,679 MU. But, the pattern of starfish toxicity in 1997 was somewhat different from that collected in 1996. The average highest specimen toxicity was 16,821MU found in November 1997. The toxin obtained from specimens collected in February, April, July and November 1997 was partially purified by YM-2 membrane ultrafiltration and Bio-Gel P-2 column chromatography. Electrophoresis, HPLC and GC-MS analyses showed that the toxins of starfish obtained from April 1997 were composed of 88% TTX and 12% PSP. The toxin of starfish collected in the other three months was found to be TTX only. Furthermore, in order to elucidate the intoxification mechanism of TTX in starfish A. scoparius, the compositions in the digestive gland of starfish were examined. It was found that the compositions in the digestive gland of less toxic starfish were mainly bivalves with Veremolpa scabra as the major species. As to the compositions in the digestive gland of more toxic specimens, collected in October and November 1997, were mainly species of gastropods, Umborium suturale and Natica pseustes. The toxicities of U. suturale, V. scabra and N. pseustes found in digestive gland of starfish were 65 MU/g, 33 MU/g and 28 MU/g, respectively. The toxins in these three mollusks were TTX and anh-TTX. The other specimens of U. suturale and N. pseustes, re-collected from the coastal waters of Pingtung Prefecture, were also found to be toxic with average toxicity value of 20±3 MU/g and 77±7 MU/g, respectively. However, V. scabra specimens were found to be nontoxic. It indicated that the starfish A. scoparius might accumulate the toxin from V. scabra and N. pseustes. Furthermore, to elucidate relationship between the toxicity and microflora in starfish viscera, the starfish A scoparius inhabiting in the coastal waters of Pingtung Prefecture was collected in November 1997 for determination of aerobic and facultative anaerobic microflora in the viscera. The results showed that the predominant bacterial genus in the viscera and other parts was Vibrio that comprised 38% and 47% of the aerobic microflora, respectively. The major isolates were V. alginolyticus and V. parahaemolyticus. On the other hand, the predominant genus of viscera was also Vibrio that comprised 51% of facultative anaerobic microflora. Moreover, HPLC, UV and GC-MS analyses demonstrated that bacteria isolated from aerobic microflora, such as Aeromonas sp., V. alginolyticus A011, A018 and A035, and V. parahaemolyticus A026 and A047 could produce TTX and/ or its related substances. TTX-producing bacteria were also found in the facultative anaerobic microflora, such as Aeromonas sp., Alcaligenes sp., Pasteurella multocida, V. alginolyticus and V. parahaemolyticus. In order to compare the TTX-producing ability of bacteria incubated aerobically and facultative anaerobically, two strains of TTX-producing bacteria V. alginolyticus AF089 and V. parahaemolyticus AF067 were enriched in BHI broth aerobically and facultative anaerobically, and then the amount of toxin was analyzed. The results showed that both strains grew better and produced more toxin in facultative anaerobic incubation than aerobic condition. Moreover, the TTX-producing ability of V. alginolyticus AF089 was much better than that of V. parahaemolyticus AF067 incubated either in aerobic or in facultative anaerobic conditions. In conclusion, Taiwanese cultured puffer T. rubripes, goby Y. nebulosus, and starfish A. scoparius all showed an ability to accumulate high toxicity of TTX or PSP. Moreover, the toxin sources of these three aquatic animals might be closely related to food chain and the intrinsic TTX-producing bacteria.
Burgoyne, David L. "Chemical studies of metabolites from Pacific Ocean marine sponges and the starfish Dermasterias imbricata". Thesis, 1992. http://hdl.handle.net/2429/2251.
Pełny tekst źródłaMaghsoodi, Bita. "The role of two extracellular matrix glycoproteins in the development of the starfish Pisaster ochraceus". Thesis, 2005. http://hdl.handle.net/2429/17198.
Pełny tekst źródłaMedicine, Faculty of
Graduate
Cowan, Zara-Louise. "Predation on the early life stages of the crown-of-thorns starfish (Acanthaster cf. solaris)". Thesis, 2017. https://researchonline.jcu.edu.au/51582/1/51582-cowan-2017-thesis.pdf.
Pełny tekst źródłaOkaji, Ken. "Feeding ecology in the early life stages of the crown-of-thorns starfish, Acanthaster planci (L.)". Thesis, 1996. https://researchonline.jcu.edu.au/27235/1/27235_Okaji_1996_thesis.pdf.
Pełny tekst źródłaCaballes, Ciemon Frank. "Environmental influences on the reproductive biology and early life history of the crown-of-thorns starfish". Thesis, 2017. https://researchonline.jcu.edu.au/51628/1/51628-caballes-2017-thesis.pdf.
Pełny tekst źródłaLee, Chi-Chiu, i 李志昭. "Studies on Bioactive Effects of Spine Venom and Asterosaponin Extract from Crown-of-Thorns Starfish (Acanthaster planci) in Taiwan". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/39281713512224043013.
Pełny tekst źródła國立臺灣海洋大學
食品科學系
103
The crown-of-thorns starfish (Acanthaster planci) is the venomous starfish as well as a destroyer of coral reefs. The crown-of-thorns starfish A. planci destroys coral reefs and has been involved in significant events, such as the crown-of-thorns starfish abnormal outbreaks. The back of A. planci is covered with many sharp spines. Previous studies showed that the crude toxin extracted from the spines exhibits the following diverse biological activities: mouse lethality, hemolytic activity, capillary permeability increasing activity, edema-forming activity, phospholipase A2 (PLA2) activity and histamine releasing activity from mast cells. In this study, the active substance extracts were done with PBS buffer. To assay the cytotoxic, hemolytic, and antioxidant properties of the water soluble extract from spine, body wall, pyloric cecum, and gonad of A. planci. Relative to other parts extract, the spine extract possessed the most biological activity, especially in cytotoxic activity. A. planci spine venom (ASV) caused hemolysis and cytotoxicity at a dose-dependent significantly. The highest activity of ASV was measured at pH 7.0-7.4; ASV-dependent hemolysis was sharply reduced when the pH was lower than 3.0 or greater than 8.0. There was almost no hemolytic activity when the concentration of Cu2+ was increased to 10 mM. Furthermore, incubation at 100 °C for 60 min sharply decreased the hemolytic activity of ASV. The cytotoxicity of ASV to human melanoma cell A375.S2 was relatively well retained at temperature less than 40°C, and sharply lost at temperature more than 80°C. The cytotoxicity of ASV also sharply lost at extreme pH environments (pH was lower than 2.0 and higher than 12.0). The cytotoxicity of ASV was attenuated when treated with Cu2+ and anti-oxidant N-acetylcysteine. In order to understand the antitumor activity of toxin from A. planci in Penghu, Taiwan, the cytotoxic toxin of A. planci venom (CAV) was purified by fast protein liquid chromatography (FPLC) and identified as plancitoxin I. The results indicated that cells after incubating with A. planci spine venom (ASV) and purified toxin (CAV) significantly decreased cell viability and lactate dehydrogenase (LDH) level in a concentration-dependent manner was increased. The assays indicated that purified toxin promoted reactive oxygen species (ROS) productions, loss of mitochondrial membrane potential (ΔΨm), and inter-nucleosomal DNA fragmentation in A375.S2 cells. Following, the study was investigated the molecular mechanism underlying the cytotoxicity function of palncitoxin I by focusing on the oxidative stress, mitochondrial dysfunction and endoplasmic reticulum (ER) stress pathway in human melanoma A375.S2 cells. The CAV was found to reduce the cellular antioxidant enzymes such as SOD and CAT, and there was significantly decreased in total thiols level and mtDNA integrity, and enhanced the lipid peroxidation. In addition, CAV increased cytosolic Ca2+ concentration, and enhanced the expression of the ER molecular chaperones GRP78 and CHOP in a dose-dependent manner. CAV significantly elevated the activity of caspase-3, -8 and -9, and reduced the ratio of Bcl-2/Bax. The results demonstrated that plancitoxin I inhibits the proliferation of A375.S2 cells through induction of oxidative stress, mitochondrial dysfunction and ER stress associated apoptosis. Many studies currently researching marine invertebrates to determine the therapeutic potential of their bioactive materials have been showing very promising results. Starfish possesses many useful pharmacological and biological characteristics. In this study, A. planci was extracted with 70% ethanol and lyophilized to obtain an ethanol fraction. The ethanol fraction was dissolved with water and defatted with petroleum ether to obtain a non-polar fraction. The residual solution was successively partitioned with ethylacetate and butanol to obtain an ethylacetate fraction and butanol fraction, respectively. Four fractions were used to examine the antioxidant and anticancer properties. The ethanol fraction of A. planci contained the highest antioxidant effects such as ABTS, DPPH, Fe2+ chelating activity and reducing power when compared with four fractions. Among the four fractions, the butanol fraction was especially shown to inhibit human malignant melanoma A375.S2 cells’ proliferation, which is involved in the apoptotic progression. This fraction could induce apoptosis and even necrosis in A375.S2 cells as evidenced by double staining with an annexin V-FITC and PI assay and DNA fragmentation analysis. These results indicated that the starfish A. planci is a good resource for obtaining the biologically active substances for antioxidant and anticancer effects. However, there was little toxicological information of asterosaponins. The study evaluated potential toxicity of the asterosaponins and analyzed the oxidative stress harm in mice. The present work evaluated the toxicity of the butanol fraction (BF) of crown-of-thorns starfish (Acanthaster planci) in ICR mice, and the BF was used as the asterosaponins extract sample. In acute toxicity assay, the LD50 of the BF is about 520.34 mg/kg body weight. In sub-acute toxicity test for 28 days, the BF significantly increases in hematological parameters, including red blood cell, hemoglobin, hematocrit and mean corpuscular hemoglobin concentration, it also causes hemolytic activities. The BF induces the hepatotoxic injury through induction of oxidative stress by elevating the lipid peroxidation and decreasing the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and total thiols. Based on microscopic observations, the BF showed harmful effect on the histomorphology change of liver. Thus, the bioactive secondary metabolites in the BF of A. planci induce a harmful effect in ICR mice.