Rozprawy doktorskie na temat „Sea squirt”
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Davis, Rohan Andrew, i davis_rohan@hotmail com. "Chemical Investigations of Great Barrier Reef Ascidians - Natural Product and Synthetic Studies". Griffith University. School of Science, 2000. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030102.104858.
Pełny tekst źródłaDavis, Rohan. "Chemical Investigations of Great Barrier Reef Ascidians - Natural Product and Synthetic Studies". Thesis, Griffith University, 2000. http://hdl.handle.net/10072/366561.
Pełny tekst źródłaThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Science
Full Text
Johnson, Sheri L. "Mating System Dynamics in a Free-Spawning Colonial Ascidian". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/JohnsonSL2007.pdf.
Pełny tekst źródłaSumerel, Andrew N. "Flume study of particle-size-dependent filtration rates of a solitary ascidian the influence of body size, flow speed, and drag /". View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-3/sumerela/andrewsumerel.pdf.
Pełny tekst źródłaLotufo, Tito Monteiro da Cruz. "Ascidiacea (Chordata:Tunicata) do litoral tropical brasileiro". Connect to this title online, 2002. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-21052002-125049/.
Pełny tekst źródłaGreen, Kathryn Margaret. "Morphological changes during normal and pertubed metamorphosis of the ascidian herdmania curvata /". St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16468.pdf.
Pełny tekst źródłaStoner, Douglas Steven. "Life History and Populationi Biology of the Colonial Ascidian Diplosoma Similis". Thesis, University of Hawaii, Honolulu, 1989. http://hdl.handle.net/10125/18144.
Pełny tekst źródłaTypescript. Thesis (Ph. D.)--University of Hawaii at Manoa, 1989. Includes bibliographical references.
Nor, Siti Mariam Mohd. "Synthesis and metal binding of cyclic peptides from sea squirts". Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438273.
Pełny tekst źródłaSwallow, Michael Andrew Carleton University Dissertation Biology. "Determination and differentiation of muscle cells in the tadpole larva of the Ascidian Boltenia Villosa". Ottawa, 1992.
Znajdź pełny tekst źródłaOdate, Shobu. "The role of vanadium as a chemical defense of the solitary tunicate, Phallusia nigra /". Electronic version (PDF), 2003. http://dl.uncw.edu/etd/2003/odates/shobuodate.html.
Pełny tekst źródłaKoman, James S. "THE PROTEOMIC RESPONSE OF SEA SQUIRTS (GENUS CIONA CONGENERS) TO HYPOSALINITY STRESS". DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/762.
Pełny tekst źródłaMaluleke, Vutlhari Absalom. "The effects of boat mooring systems on squid egg beds during squid fishing". Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2528.
Pełny tekst źródłaIn South Africa, squid fishing vessels need to find and then anchor above benthic squid egg beds to effect viable catches. However, waves acting on the vessel produce a dynamic response on the anchor line. These oscillatory motions produce impact forces of the chain striking the seabed. It is hypothesised that this causes damage to the squid egg bed beneath the vessels. Different mooring systems may cause more or less damage and this is what is investigated in this research. The effect of vessel mooring lines impact on the seabed during squid fishing is investigated using a specialised hydrodynamic tool commercial package ANSYS AQWA models. This study analysed the single-point versus the two-point mooring system’s impact on the seabed. The ANSYS AQWA models were developed for both mooring systems under the influence of the wave and current loads using the 14 and 22 m vessels anchored with various chain sizes. The effect of various wave conditions was investigated as well as the analysis of three mooring line configurations. The mooring chain contact pressure on the seabed is investigated beyond what is output from ANSYS AQWA using ABAQUS finite element analysis. The real-world velocity of the mooring chain underwater was obtained using video analysis. The ABAQUS model was built by varying chain sizes at different impact velocities. The impact pressure and force due to this velocity was related to mooring line impact velocity on the seabed in ANSYS AQWA. Results show the maximum impact pressure of 191 MPa when the 20 mm diameter chain impacts the seabed at the velocity of 8 m/s from video analysis. It was found that the mooring chain impact pressure on the seabed increased with an increase in the velocity of impact and chain size. The ANSYS AQWA impact pressure on the seabed was found to be 170.86 MPa at the impact velocity of 6.4 m/s. The two-point mooring system was found to double the seabed mooring chain contact length compared to the single-point mooring system. Both mooring systems showed that the 14 m vessel mooring line causes the least seabed footprint compared to the 22 m vessel.
Parker-Nance, Shirley. "Aplousobranch ascidians (Tunicata: Ascidiacea) from Southern Africa". Thesis, University of Port Elizabeth, 2003. http://hdl.handle.net/10948/311.
Pełny tekst źródłaSerafini, Loredana. "The proteomic response of sea squirts (genus Ciona congeners) to heat stress: Evidence for differential thermal sensitivities". DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/443.
Pełny tekst źródłaMiyahara, Kazutaka. "Fishery biological studies of the diamond squid Thysanoteuthis rhombus in the Sea of Japan". Kyoto University, 2006. http://hdl.handle.net/2433/136643.
Pełny tekst źródłaBarnes, Peter Brendan. "Environmental impacts and the ecology of sponges and ascidians in south-eastern Australian coastal lakes and lagoons". Department of Biological Sciences - Faculty of Science, 2009. http://ro.uow.edu.au/theses/849.
Pełny tekst źródłaGomes, André Rafael Lestre. "Arquiteturas do mar. Contributo arquitetónico para o problema da subida da água do oceano. Um estudo para Lisboa". Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/26738.
Pełny tekst źródłaSvenman, Edvard. "Inductive measurement of narrow gaps for high precision welding of square butt joints". Licentiate thesis, Högskolan Väst, Forskningsmiljön produktionsteknik(PTW), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-10150.
Pełny tekst źródłaBromley, Candice Leigh. "The chemistry of Algoa Bay ascidians". Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/d1020606.
Pełny tekst źródłaSmith, Jennifer. "Biological influences on the three-dimensional habitat use of juvenile New Zealand sea lions (Phocarctos hookeri) with a squid trawl fishery: Implications for conservation managment". Thesis, Smith, Jennifer (2015) Biological influences on the three-dimensional habitat use of juvenile New Zealand sea lions (Phocarctos hookeri) with a squid trawl fishery: Implications for conservation managment. Masters by Research thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/27774/.
Pełny tekst źródłaMohamad, Isa Muammar Bin. "Low Noise Amplifiers using highly strained InGaAs/InAlAs/InP pHEMT for implementation in the Square Kilometre Array (SKA)". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/low-noise-amplifiers-using-highly-strained-ingaasinalasinp-phemt-for-implementation-in-the-square-kilometre-array-ska(31b6cbae-7b7e-43fe-a612-b3555dd2263d).html.
Pełny tekst źródłaVelayutham, Sunitadevi. "The influence of classroom environment on students’ motivation and self-regulation". Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1717.
Pełny tekst źródłaCasso, Carrasco Maria. "Genomic analysis of an introduced ascidian and implications for invasiveness". Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/673998.
Pełny tekst źródłaAhmad, Norhawati Binti. "Modelling and design of Low Noise Amplifiers using strained InGaAs/InAlAs/InP pHEMT for the Square Kilometre Array (SKA) application". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/modelling-and-design-of-low-noise-amplifiers-using-strained-ingaasinalasinp-phemt-for-the-square-kilometre-array-ska-application(b2b50fd8-0a13-4f71-b3f0-616ee4b2a82b).html.
Pełny tekst źródłaMeynier, Laureline. "Feeding ecology of the New Zealand sea lion (Phocarctos hookeri) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor Philosophy in Zoology at Massey University, Palmerston North, New Zealand". Massey University, 2009. http://hdl.handle.net/10179/901.
Pełny tekst źródłaBarreto, Marco Antonio Zanussi. "Dinâmica longitudinal : efeitos da geometria de suspensão nas mudanças de atitude da massa suspensa e os esforços nos elementos da suspensão". Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-22122005-165842/.
Pełny tekst źródłaThis work has objective study the influence of suspension geometry on the sprung mass attitudes. It presents a confrontation among works and authors and this segmented in three parts; where in the first part the basic concepts are defined, dive, squat, lift, anti-dive, anti-squat, anti-lift and equivalent trailing-arm; in the second part the limitations are presented and the new concepts are defined for R. S. Sharp and in the third part are presented the bidimensional dynamic model introduced by Fu-Cheng Wang. It presents a virtual model in system of multi-bodies developed in the program ADAMS, with all the subsystems that composes a complete vehicle. It innovates when bringing such object to study one vehicle of competition (formula SAE) that it has a particularity suspension system push-rod. It surprises with results because its opposite of the basic concepts which is present in the majority of books
Mohd, Mustamil Norizah. "The influence of culture and ethical ideology on ethical decision making process of Malaysian managers". Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/646.
Pełny tekst źródłaKincaid, Erin Suzanne. "Biofouling Management in the Pacific Northwest and Predation on Native versus Non-native Ascidians". PDXScholar, 2016. http://pdxscholar.library.pdx.edu/open_access_etds/3069.
Pełny tekst źródłaCampos, Anderson Luis Saber. "Efeitos de demanda e de oferta na estrutura de capital de companhias abertas no Brasil". Universidade Presbiteriana Mackenzie, 2007. http://tede.mackenzie.br/jspui/handle/tede/673.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
From the theory on structure of capital and the application of structural equations a model was considered to evaluate the indebtedness of the public companies in Brazil. The effect of direct and indirect costs of bankruptcy, tax benefits, agency costs of free cash flow and the agency costs of borrowing. Computed the results, which was opted to analyzing an alternative model that indicates the relevance of the capital demand and offers effects in the level of companies indebtedness. One met evidences on the relevance of direct and indirect costs of bankruptcy and agency costs of borrowing in the determination of the capital structure in analyzed companies.
A partir da teoria sobre estrutura de capital e da aplicação de equações estruturais foi proposto um modelo para avaliar o endividamento das companhias abertas no Brasil. Foram considerados os efeitos das dificuldades financeiras, benefícios fiscais, agency de capital próprio e de capital de terceiros. Computado os resultados optou-se por analisar um modelo alternativo segundo o qual encontramos indícios e relevância dos efeitos da demanda e oferta de capital no nível de endividamento das empresas. Encontrou-se evidências que dificuldades financeiras e agency de capital de terceiros influem na determinação da estrutura de capital das empresas analisadas.
Villoutreix, Paul. "Aléatoire et variabilité dans l’embryogenèse animale, une approche multi-échelle". Thesis, Sorbonne Paris Cité, 2015. http://www.theses.fr/2015PA05T016/document.
Pełny tekst źródłaWe propose in this thesis to characterize variability quantitatively at various scales during embryogenesis. We use a combination of mathematical models and experimental results. In the first part, we use a small cohort of digital sea urchin embryos to construct a prototypical representation of the cell lineage, which relates individual cell features with embryo-level dynamics. This multi-level data-driven probabilistic model relies on symmetries of the embryo and known cell types, which provide a generic coarse-grained level of observation for distributions of individual cell features. The prototype is defined as the centroid of the cohort in the corresponding statistical manifold. Among several results, we show that intra-individual variability is involved in the reproducibility of the developmental process. In the second part, we consider the mechanisms sources of variability during development and their relations to evolution. Building on experimental results showing variable phenotypic expression and incomplete penetrance in a zebrafish mutant line, we propose a clarification of the various levels of biological variability using a formal analogy with quantum mechanics mathematical framework. Surprisingly, we find a formal analogy between quantum entanglement and Mendel’s idealized scheme of inheritance. In the third part, we study biological organization and its relations to developmental paths. By adapting the tools of algebraic topology, we compute invariants of the network of cellular contacts extracted from confocal microscopy images of epithelia from different species and genetic backgrounds. In particular, we show the influence of individual histories on the spatial distribution of cells in epithelial tissues
Shakeri, Shadi. "Modeling Information Seeking Under Perceived Risk". Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1404510/.
Pełny tekst źródłaSereda, Alena. "Metody rozptylu světla a kalorimetrie ve studiu systémů hyaluronan-albumin". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240559.
Pełny tekst źródłaLeitão, Franklin Delano Cavalcanti. "Métodos sem malha: aplicações do Método de Galerkin sem elementos e do Método de Interpolação de Ponto em casos estruturais". Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=8611.
Pełny tekst źródłaMeshless are certainly very researched in many countries that are in state of art of scientific knowledge. However these methods are still unknown by many brazilian universities. To create more diffusion or, for many people, to introduce them, this work tries to understand the meshless based on solid mechanic applications. So basic concepts of meshless and its historic development are introduced since its origin, with smooth particle hydrodynamic until partition of unity, its more general form. In this context, most traditional form of meshless was investigated deeply: element free Galerkin method and also another different method: point interpolation method. This way characteristics, advantages and disadvantages, comparing to finite elements methods, are introduced by applications in analyses in bars and plates in state of plane stress. This work still researched an important area of meshless application, fracture mechanical, to understand how a crack is computationally represented, particularly, with visibility and diffraction criterions. By these criterions and using fracture mechanical concepts, stress intensity factor is calculated by J-integral concept.
Ngwanya, Olwethu. "Molecularly imprinted polymers for detection of volatile organics associated with fuel combustion". University of the Western Cape, 2018. http://hdl.handle.net/11394/6363.
Pełny tekst źródłaPollutants such as polycyclic aromatic hydrocarbons (PAHs) are known for their toxic effects which may lead to the cause of degenerative diseases in both humans and animals. PAHs are widespread in the environment, and may be found in water, food, automotive industry and petrochemical industries to name but a few sources. Literature reports have highlighted industrial workplace exposure to PAHs as a leading cause for development of cancer in workers. Particularly, workers in the petrochemical industry are adversely affected and the incidence of skin and lung cancer in this population group is high. The United States of America in its guidelines developed by environmental protection agency (EPA) has identified 18 PAHs as priority pollutants. Among these are anthracene, benzo[a]pyrene and pyrene which have been selected as the focal point of this study due to their significance in the petrochemical industry. Due to the carcinogenic and mutagenic properties reported in literature for certain PAHs, there have been monitoring procedures taken in most countries around the world. The commonly used analytical methods for the detection of PAHs from industrial samples are high performance liquid chromatography (HPLC) coupled to fluorescence detection, membrane filtration, ozonation and reverse osmosis. Analysis of PAHs from the petrochemical industry is typically performed by HPLC method as well as sono-degredation in the presence of oxygen and hydrogen peroxide.
Huang, Tzu-yun, i 黃子芸. "Complete Mitochondrial DNA Sequence Analyses of the Sea Anemones Mesactinia genesis and Heteractis aurora as well as the Sea Squirt Eudistoma gilboviride of Taiwan". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/54319628729963572651.
Pełny tekst źródła國立中山大學
海洋生物科技暨資源學系研究所
97
Complete DNA sequences were determined for the mitochondrial (mt) genomes of the sea anemones, Mesactinia genesis (20,544 bp), Heteractis aurora (19,800 bp) and partial mtDNA between cox2 and nad4 of the Calliactis sp. (3,713 bp). In addition, complete mtDNA sequences were determined for the sea squirt, Eudistoma gilboviride (14,203 bp). The circular, sea anemones genomes contain the genes for 13 energy pathway proteins and two ribosomal RNAs and two transfer RNAs. H. aurora contains a previously undescribed ORF between the cox2 and nad4 genes encoding a putative protein of 646 amino acids. In M. geneisis and Calliactis sp. encodes two separate smaller ORFs of 259 and 243 as well as 269 and 345 in the corresponding regions, respectively. Possible control region of the mitochondrial genomes of M. geneisis and H. aurora were identified in the intergenic region 13. The sea squirt genomes contain the genes for 11 energy pathway proteins and two rRNAs and 22 tRNAs. All genes are encoded by the heavy strand, except for trnM, trnK, and trnV, which are encoded by the light strand. The ascidians showed frequent and extensive gene rearrangement. The gene order in E. gilboviride are very much different from the other ascidians mt-genome. The E. gilboviride mtDNA does not encode the nad6 and a tpyical atp8. Molecular phylogenetic analyses based on nucleic acid and amino acid sequences of the deuterostome (echinoderms, chordate and Xenoturbella), and cnidaria coincide with the morphological characters.
Sherrard, Kristin M. "A comparative study of early juvenile feeding performance in ascidians /". 2003. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3088784.
Pełny tekst źródłaHurlbut, Catherine Jane. "Variations in larval density and settlement in space and time : important determinants of recruitment in sessile marine invertebrates?" Thesis, 1990. http://hdl.handle.net/10125/10315.
Pełny tekst źródłaLin, Pao-Chien, i 林報儉. "A study on the adjustment of deep-sea squid fishery in Taiwan". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/00969661041306428612.
Pełny tekst źródła國立臺灣海洋大學
應用經濟研究所
95
After more than thirty years of endeavors, Taiwanese squid fishery has established its status in the deep sea fishery. However, facing rising oil price, unstable resources, high fishing access fee, and competition from a large number of Chinese fishing vessels, the industry has been confronted with extreme crisis and challenge for its survival. Using cost-benefit cross tabulation analysis and direct interviews with business owners, this study investigates the major difficulty of Taiwan’s deep sea squid fishery and searches for solutions. The main sources of data come from “Economic Survey of Taiwan Deep Sea Fishery” and personal interviews of ship owners in Kaohsiung Qianchen fishing port. Cost-benefit analysis is utilized to analyze important cost items such as operating expenses in fishing, labor, sales, management and maintenance costs of the vessel and its equipment. Research results are as follows: 1) Operating expenses account for the greatest portion of the total cost in both fishing solely squid and fishing squid with saury as by catch, reaching 51.8% and 52.2%, respectively, while labor expenses, the second largest item, account for 24.4% and 23.0% respectively. The above two items constitute as much as 75% of the total cost. 2) In terms of profitability, Taiwan squid fishing vessels did not do well in 2003, 2004 and 2005. At best, they were only able to recover fixed cost. 3) Ship owners generally expect government to take measures to assist them in promotion of market expansion and fishery cooperation with the coastal nations owning the resources in order to lessen the difficulty in operation.
Yang, Li-Chung, i 楊立中. "Economic Analysis on the Production of Deep-sea Squid Fishery in Taiwan". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/99253098177152856137.
Pełny tekst źródła國立臺灣海洋大學
應用經濟研究所
93
Abstract Deep-sea Squid fishery is an important fisheries industry in Taiwan. However, in the recent years, it faces with the problem of increasing production costs which resulting in the lost of compatibility in the world fishery. It is important to control the production cost and raise the efficiency of operation. Therefore this paper aims to analyze the cost-benefit structure of the industry, the key factors of increase of the production cost. The study also uses SUR as a method to estimate the cost function of the industry so as to find out the possible solution for the cost control. The paper also deals with a SWOT analysis on the industry. With the study of the paper, we obtain the major finding as follows. 1. The major expense of the deep-sea Squid fishing industry is the expense of traveling on the sea, which account for 41.14% of the total cost. Within the cost fuel expense ranks the first item in the total. 2. The average net profit of the industry is about 1.52% which is quite low when compare to other fishing industries. 3. Base on an empirical study of cost function, fishing boats in the size of 900-1000 ton is more costly than others. Base on Allen’s partial elasticity of substitution, we also find that the factors between capital and labor are in substitution; however labor cost and the expense of traveling in the sea are in the relation of complementary. Which means that in order to control the production cost it is important to shrink the labor cost by improve its automation for the fishing boats. In order to raise their profit, it is also important to improve their marketing efforts.
Rafael, Ana Patrícia Mil-Homens. "Contaminants in deep-sea glass squids (Cranchiidae) from the eastern tropical Atlantic oxygen minimum zone". Master's thesis, 2017. http://hdl.handle.net/10451/30267.
Pełny tekst źródłaO oceano constitui grande parte do planeta, acomodando cerca de 1 368 milhões Km3 de água, providencia mais espaço que todos os habitats terrestres. Apesar da maioria da biodiversidade marinha se encontrar na zona fótica e menos profundas, uma grande variedade vive nas partes mais profundas e sem luz. Em algumas partes do oceano, entre os 10 e os 1 300m, existem zonas de oxigénio mínimo (ZOM). Estes habitats pelágicos apresentam condições estáveis de níveis baixos e persistentes de oxigénio e baixas temperaturas ao longo de vastas áreas. Estes habitats resultam de uma combinação de uma fraca ventilação assim como pouca circulação da água. A maioria das ZOM exibe um perfil de oxigénio semelhante, mas os níveis de oxigénio, espessura e a profundidade de ocorrência podem variar regionalmente. No Atlântico Tropical Oriental, a uma profundidade entre os 200m a 800m, existe uma zona mínima de oxigénio localizada entre o sistema da Corrente Equatorial (a Sul) e a Corrente Equatorial Norte (a Norte). Aqui, o perfil de oxigénio tem dois mínimos a cerca de 70m e 400m de profundidade, com o mínimo mais proeminente entre o Senegal e a Ilha de Cabo Verde. Os cefalópodes (classe Cephalopoda) podem ser encontrados em todos os oceanos do mundo, desde águas costeiras ao mar profundo, e algumas espécies conseguem viver em condições extremas, como as fontes hidrotermais e as ZOM. A maioria destes moluscos são predadores oportunistas com altas taxas de crescimento, uma única época de reprodução e uma esperança média de vida curta nas zonas costeiras. No mar profundo, estas características biológicas são bastante diferentes, dado que as suas capacidades locomotoras e requisitos metabólicos são mais reduzidos. De uma forma geral, os cefalópodes desempenham um papel fundamental nos ecossistemas marinhos, uma vez que são uma fonte primária de alimento para muitos predadores marinhos, como peixes, mamíferos marinhos ou aves marinhas. Os cranchídeos (família Cranchiidae) estão entre as lulas mais abundantes do mundo, de grande diversidade morfológica em ambientes pelágicos. A maioria delas têm uma aparência transparente (por isso designadas também por lulas de vidro) dado possuírem grandes cavidades celómicas cheias de fluido amoniacal neutro e de baixa densidade, que lhes confere flutuabilidade neutra. Embora a sua morfologia e anatomia estejam bem estudadas, e de serem muito abundantes, pouco se sabe sobre a sua biologia e ecologia. Muitas das espécies de cranchídeos passam grande parte de sua vida em águas onde quase não há luz ou em completa escuridão. A maioria desses pequenos animais não depende da velocidade para escapar de predadores, mas sim de outras estratégias defensivas, - a sua transparência, que sob condições de iluminação adequadas, as tornam praticamente invisíveis. A poluição marinha tornou-se um problema muito grave durante as últimas décadas, devido aos seus impactos na biodiversidade e no funcionamento dos ecossistemas. A presença de concentrações acima do normal de contaminantes já foi detetada em vários tipos de habitats marinhos, nomeadamente no mar profundo, onde a preocupação tem vindo a aumentar devido à possibilidade de este, devido à sua dimensão, se poder tornar no maior depósito para tais elementos. A bioacumulação tem sido amplamente estudada em muitos organismos marinhos e demonstrou-se que os moluscos, como os cefalópodes, têm a capacidade de acumular altos níveis de contaminantes. As maiores concentrações determinadas são o carbono, hidrogénio, azoto, oxigénio e enxofre, que são elementos estruturais. Outros elementos encontrados podem ser essenciais, cujo papel biológico é conhecido, como ferro, cobre, zinco, iodo, manganês, selénio ou flúor. Os não essenciais, não têm um papel conhecido nas funções fisiológicas, como ocorre com mercúrio, chumbo e cádmio. Embora existam estudos sobre a acumulação de elementos em cefalópodes, a maioria está focada em espécies comerciais. Entre essas espécies, foram geralmente registados altos níveis de metais, como o cádmio, o cobre e o zinco, tornando os cefalópodes uma potencial via de transporte de contaminantes para níveis tróficos superiores. A absorção de contaminantes por organismos marinhos pode ocorrer a partir da água, incluindo partículas em suspensão, alimentos e sedimentos. Outros fatores, como a disponibilidade de elementos na água, período de exposição, temperatura, tamanho, sexo, estágio de maturidade e local de captura, também são importantes na acumulação de metais nos tecidos destes organimsos. É importante referir que dado que os cefalópodes apresentam uma vida curta e uma alta acumulação de contaminantes, estes organismos podem refletir as condições actuais do ambiente onde vivem e serem utilizados como indicadores de contaminação ambiental. Embora não haja informações sobre contaminantes nos cranchídeos, existe informação sobre outras espécies de cefalópodes, incluindo outras lulas oceânicas. A maioria dos estudos mostrou a capacidade dos cefalópodes de concentrar Zn, Cu e Cd na glândula digestiva mesmo em ambientes com baixa disponibilidade. Neste contexto, o objetivo desta dissertação, foi determinar, pela primeira vez, as concentrações de alguns elementos (V, Cr, Co, Ni, Cu, Zn, As, Se, Cd e Pb) nos tecidos (glândula digestiva, manto e tentáculos) de nove espécies de cranchídeos, da ZOM de Cabo Verde. As lulas foram apanhadas na zona económica exclusiva de Cabo Verde, em oito estações de amostragem, através da utilização de redes pelágicas MOCNESS e IKMT em diferentes profundidades. Os indivíduos capturados foram identificados até à espécie (quando possível) e preservados em azoto líquido abordo do RV Maria S. Merian e depois transferidas para -80ºC no laboratório. Os indivíduos foram dissecados de modo a separar o manto, os tentáculos e a glândula digestiva. Neste trabalho, foram detectadas diferenças significativas entre espécies de cranchídeos e entre os diferentes tecidos analisados. De uma forma geral, os elementos na glândula digestiva variaram entre os 0,070 e 17 μg g-1 peso seco, com as concentrações variando da seguinte forma decrescente: Zn > Cd > As > Cu > V > Se > Co > Cr > Ni > Pb. No manto variaram entre os 0,070 e 28 μg g-1 peso seco, com as concentrações variando da seguinte forma decrescente: Zn > Cu > Cr > As > V > Ni > Se > Cd > Pb > Co. Nos tentáculos, os contaminantes variaram entre os 0,13 e os 24 μg g-1 peso seco, com as concentrações variando da seguinte forma decrescente: Se > Zn > As > Cu > Cr> Ni > V > Cd > Co > Pb. Estes resultados em comparação com os de outros grupos de cefalópodes (nomeadamente chocos, polvos e outras lulas pelágicas) mostraram que as espécies pelágicas (lulas) apresentavam menores concentrações de Cd do que as espécies bentónicas (polvos) ou nectobentónicas (chocos). Essas diferenças podem ser atribuídas às diferentes concentrações de Cd nas suas presas, uma vez que as presas bentônicas (crustáceos e bivalves) têm maiores concentrações de Cd, do que os peixes que são presas preferenciais de espécies pelágicas. Em relação às espécies nectobentónicas e bentónicas, os sedimentos também podem ser uma via de acumulação - embora a transferência direta seja menor, podem atuar como uma fonte indireta de contaminantes. Por último, as diferenças com os nautilus podem estar relacionadas com diferentes tempos de vida, uma vez que os nautilus vivem entre os 10 e os 15 anos, enquanto os Coleoids (choco, lulas e polvos) vivem entre 1 a 3 anos. Embora a expectativa de vida da maioria dos cranchídeos não seja conhecida, não é provável que os indivíduos estudados atinjam essas idades. É importante notar que os músculos dos cranchídeos apresentaram maior variação e uma maior concentração do que as outras espécies de cefalópodes. Estes resultados não eram esperados e levanta a questão porque é que os cranchídeos concentram elevados níveis de alguns elementos nestes tecidos. A capacidade dos cefalópodes para concentrar altos níveis de metais sem um sinal de toxicidade, está associada a eficientes processos de desintoxicação que permitem reter os elementos de forma não metabolicamente disponível, limitando assim a sua toxicidade. Neste contexto, a glândula digestiva é um órgão complexo envolvido em várias funções, como digestão, secreção e desintoxicação (entre outros). Por ser considerado um tecido de armazenamento, é também um órgão-chave para a desintoxicação. Não surpreendentemente, mas com algumas exceções (por exemplo, Hg e As), a maioria dos contaminantes são encontrados em concentrações mais elevadas neste tecido. Pensa-se que inicialmente os contaminantes estão ligados a proteínas solúveis, o que implica que as células da glândula digestiva provavelmente estarão envolvidas na desintoxicação dos contaminantes. Esta associação com proteínas citosólicas, inibe as interações tóxicas de iões metálicos com locais de ligação sensíveis (proteínas, moléculas ou estruturas celulares). Além disso, uma vez que os metais como Ag, Cd, Cu, Hg e Zn têm uma alta afinidade para as metalotioninas, pensa-se que estas desempenham um papel fundamental na homeostasia dos metais essenciais, bem como um papel importante na tolerância dos organismos a elementos não-essenciais. Estudos anteriores mostraram que não é só o Cd, mas também outros contaminantes, como Co, Cr, Ni e V, são encontrados em concentrações mais elevadas na glândula digestiva do que no músculo. No entanto, nos cranchídeos, e apesar de o Co ter apresentado concentrações mais elevadas na glândula digestiva, o V, Cr e Ni apresentaram valores mais elevados no manto. Quanto às diferenças entre manto e tentáculos, estas podem ser devido a diferentes composições proteicas e respectivos sistemas enzimáticos, podendo explicar os resultados obtidos com os cranchídeos Em suma, o fato das lulas de vidro, que prosperam em ambientes pelágicos profundos, exibirem concentrações de contaminantes semelhantes aos encontrados nos cefalópodes costeiros (cujos habitats estão sujeitos a uma maior intervenção humana), é inesperado. Estes dados corroboram a ideia corrente de que esses ambientes remotos estão-se a tornar o principal acumulador de contaminantes no planeta.
Trace elements are persistent and have been detected in a wide range of environments, including the deep-sea, where the concern is increasing, as it might act as a global sink for them. One group of cephalopods that thrive in such harsh environments, including the mesopelagic oxygen minimum zones, are the cranchiid (glass) squids. Although their anatomy and morphology is well understood, little is known about their biology and ecology. Elemental bioaccumulation has been greatly studied in many marine organisms and it has been shown that cephalopods have the ability to accumulate high levels of elements. The uptake of trace elements can occur from water, including suspended particulate matter, food and sediments. Because cephalopods display a short life span and high accumulation of trace elements, these characteristics may clearly reflect the ambient life conditions and indicators of environmental contamination. Yet, up to our knowledge, there is no information about trace elements in the deep cranchiid squids. Within this context, the aim of the present dissertation was to determined, for the first time, the concentrations of V, Cr, Co, Ni, Cu, Zn, As, Se, Cd and Pb in the digestive gland, mantle and tentacles of nine different cranchiid squids from the Cape Verde Exclusive Economic Zone in the Eastern Atlantic Ocean. Concomitantly, a comprehensive comparison with trace elements obtained in shallow-living cephalopod species (including cuttlefish, octopods and other squids) was also conducted. In general, trace elements in cranchiid digestive gland ranged between 0.07 and 17 μg-1 dw, with the following average concentrations in descending order: Zn > Cd > As > Cu > V > Se > Co > Cr > Ni > Pb. In the mantle ranged between 0.07 and 28 μg g-1 dw, with the following average concentrations in descending order: Zn > Cu > Cr > As > V > Ni > Se > Cd > Pb > Co. In the tentacles, trace elements ranged between 0.13 and 24 μg g-1 dw, with the following average concentrations in descending order: Se > Zn > As > Cu > Cr> Ni > V > Cd > Co > Pb. The high Cd levels in cranchiid squids may be related to the enriched environment around Cape Verde islands, with dissolved Cd being reinjected in the water column by the upwelling of subsurface waters. Additionally, another route of contamination could be from the Saharian dust deposition, which represents an important source of trace elements (Co, Ni, Zn and Cd) into the Atlantic Ocean. In the present work, it also became evident that benthic cephalopod species showed higher concentrations of Cd than the pelagic conspecifics. These differences could be attributed to distinct trophic ecologies (different trace elements concentrations on their preys). Previous studies have also shown that not only the Cd but also other trace elements, like Co, Cr, Ni and V are found at higher concentrations in the digestive gland (the major storage site and a key organ for detoxification) than in the muscle. These findings were not corroborated here, since while Cd and Co levels were higher concentrations in the digestive gland, V, Cr and Ni have higher concentration values in the mantle. Last, it is worth noting that the fact that glass (transparent) squids that thrive in deep pelagic environments display trace elements concentrations as high as those found in coastalcephalopods, which live in habitats exposed to enhanced anthropogenic forcing, is quite surprising. These findings corroborate the on-going notion that such remote environments are now the major global sink for contaminants in the planet.
Tristancho, Ruiz Sofia. "The status of the invasive sea squirts and barnacles found in the marinas and ports of Algarve, Southern Portugal". Master's thesis, 2015. http://hdl.handle.net/10400.1/7893.
Pełny tekst źródłaExotic species have been considered by several authors as the worst threat that can occur to native biodiversity. Due to the lack of information on sea squirts and barnacle invaders in southern Portugal, the first step of this study aims to detect and identify their presence in the ports of the region. A comparison reporting differences between these ports was performed: i) fishing and recreational; ii) port location; iii) sheltered versus unsheltered facilities. The localities of Lagos, Quarteira-Vilamoura, Faro and Olhão were the study areas where seasonal sampling was done. A case study to obtain the total recruitment for the invasive species was also carried out, comparing surfaces and removal of invaders. Higher percentages of invasive species were found (60% for barnacles and 58.3% for sea squirts). The appearance of one invasive gastropod, originating in the West African coast, was reported in European waters the first time. Besides, for barnacle and sea squirt counting, there were significant differences in all comparisons except between seasons for barnacles and type of port for sea squirts. The main differences in the abundance, frequency of occurrence and communities seems to be related with the transit of international vessels, the settlement period and the conditions presented between ports in terms of exposure to the sea. Differences between surfaces during the case study were found, showing wallets as the best surface for sea squirts and cement plates for barnacles in general. Cement can be considered as the best surface for recruitment for the invasive Amphibalanus amphitrite in relation with the huge abundance found. The other two invasive Amphibalanus cf. eburneus and Styela plicata found during the experiment, did not present any preference between surfaces. So in general for the three invasive species of this area the use of cement plate guarantees a high rate of recruitment.
Yin, Chang. "Fisheries Acoustic Studies on the Purpleback Flying Squid Resource in the South China Sea". 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2601200514224200.
Pełny tekst źródłaChang, Yin, i 張引. "Fisheries Acoustic Studies on the Purpleback Flying Squid Resource in the South China Sea". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/11607052457512190700.
Pełny tekst źródła國立臺灣大學
海洋研究所
93
The fisheries acoustic technique, which is capable of directly assessing underwater populations over a large volume of waters in a short time, makes it a powerful tool for fisheries scientists. This paper dealt with the application of such technique to investigate the unexploited Purpleback Flying Squid (Sthenoteuthis oualaniensis) resource in the South China Sea. The results summarized as follows: (1) Mantle Length (ML) survey using especially designed squid jigger, which can cast down to a specific depth with notification of catching a squid specimen, as well as concurrent collection of in situ Target Strength (TS) using EK500 scientific echosounder were carried out and the results show : (i) the larger the ML the stronger the in situ TS; (ii) seasonal mean in situ TS of squid and its corresponding ML are -51.2dB and 15.0cm, in spring (February-April); -48.2dB and 18.9cm appeared in summer (May-July), -49.3dB and 17.1cm in autumn (August-October), -54.1dB and 13.8cm in winter (November-January), respectively. (2) A searching with validation algorithm was developed in this study to acquire the logarithm-linear relationship of in situ TS versus ML of the squid. The results are as follow: for ML from 10cm to 32cm. According to the depth range dispersion echoed by in situ squid TS, squid concentration of nighttime appeared in water column depth of 10-210m in spring and autumn; appeared in depth of 10-160m in summer and winter. (3) A procedure to extract the echo energy of squid signals from the total echo energy was developed, as to filter noises that mainly composed of background noise and. The precision improvement in Volume backscattering Strength (SV) due to such procedure is estimated about 11%. (4) Seasonal mean SV, which is essential for estimating abundance, of the squid obtained in this study show that: -77.9 dB in spring 1999, -70.6 dB in summer 1998, -75.8 dB in autumn 1999 and -72.2 dB in winter 1999. Seasonal mean squid abundance thus derived appeared to be 4.2 in spring; 8.9 in summer; 5.1 in autumn; and 26.1 in winter. (5) Female Gonad Index (GI), which is the ratio of gonad weight to total body weight multiplied by 100, is analyzed in this study. The results show: that GI is a good indicator for female maturation; GI larger than 3 (ML larger than 20cm) indicating a matured female, smaller than 2 (ML smaller than 15cm) indicating immature ones. Squids caught by in situ biological sampling device appeared that all matured in summer and all immatured in winter while both matured and immatured squid present in spring and autumn. (6) Assumed that the population of the Purpleback Flying Squid in the South China Sea was an enclosed stock and under a steady population condition in recent years, the basic population characters of this squid was postulated as follow: the main spawning season occurs in summer; the major detectable recruitment (ML large than 9 cm) occurs in winter with rather high density; yet the survival rate of this recruitment in next spring appeared to be low (about 20%). (7) The total surveyed one-degree square block area, within which biological survey conducted in this study has captured Purpleback Flying Squid, is about . The abundance of Purpleback Flying Squid in the South China Sea is estimated as individuals in summer 1998, which is also the spawning season of this species. The mean body weight of the squid in this season is about 0.3 kg, thus the estimated total standing stock size of this resource was about 1500 thousand metric tons in the offshore regions of the South China Sea.
Cheng, Chao Jen, i 鄭釗仁. "Profitability analysis on the mangement of deep-sea squid jigg- ing fishery in Taiwan". Thesis, 1994. http://ndltd.ncl.edu.tw/handle/15108252220255200385.
Pełny tekst źródła國立中山大學
海洋資源學系
82
The deep-sea squid jigging fishery of Taiwan began at 1972 , and the trandational fishing grounds included the New Zealand waters , the northwest Pacific and the southwest Atlantic . The southwest Atlantic was the only squid jigging fishing ground with economic value in 1993 . This study analyzed the profitability and fuel oil average product of 700 ton-class (701-800 tonnage) and 800 ton-class ( 801-1000 tonnage) squid jigging fishery in the southwest Atlantic from 1991 to 1993 . The results were as follows : 1.profitability By means of the present value method , the profitability of 800 ton-class was better than that of 700 ton-class . The reasons were : (1) The average variable cost of the 800 ton-class was about 30-50﹪ higher than that of 700 ton-class , but the former''s fi- shing revenue was about 40-100﹪ higher than the latter''s . (2) Among the direct costs , the fishing oil was the biggest one that averaged 13.51﹪ of the 700 ton-class'' average variable cost. The cooperative license fee was the biggest one that ave- raged 15.56﹪ of the 800 ton-class'' average variable cost. As for the indirect costs , the depreciation was the bigg- est one between 700 and 800 ton-class''. (3) 800 ton-class'' average fish price was about 31.7﹪ higher than break-even price , and 700 ton-class'' had only about 3.7﹪. (4) 800 ton-class'' average fish product was about 33﹪ higher than break-even product , which was much better than 4﹪ higher of 700 ton-class''. 2.fuel oil average product Having analyzed the data , this study got the conclusion that 800 ton-class was superior in fuel oil average product to 700 ton-class due to the following reason : 800 ton-class'' average value of fuel oil product averaged 10.24﹪ , which was higher than 700 ton-class'' 8.63 .
Hsu, Yu-Jie, i 許語婕. "Stock assessment of swordtip squid (Uroteuthis (Photololigo) edulis) in the southern East China Sea". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/94203493601766746932.
Pełny tekst źródła國立臺灣海洋大學
環境生物與漁業科學學系
103
Neritic squid is a short-lived species of which usually vulnerable to environmental conditions and shows great variation in annual abundance. Swordtip squid, Uroteuthis (Photololigo) edulis, is a neritic squid distributed in subtropical and tropical coastal water in the Indo-western Pacific. This species plays a critical role in marine ecosystems and also an important fisheries resource. Production of neritic squid for the neritic and coastal fisheries of Taiwan ranged from 3,398 to 19,381 tons during 1986-2013, of which production from the southern East China Sea (SECS, production of New Taipei city and Keelung city) accounted of 52%. The squids are targeted by torch-light net and trawl fleet. The SECS is an important fishing grounds for neritic squid fishery of Taiwan, however, the production of neritic squid was decreasing in recent years. Studies on squid stock assessment and abundance trend is scarce in this region. In this study, catch data of neritic squid fleet (mainly torch-light net fleet) from the SECS from 2002 to 2013 are analyzed. The fishing efforts of individual vessel are standardized by comparing relative CPUE of each paired-vessel in the same day and location. Abundance of the neritic squid is estimated by the depletion method. Annual number of sample vessels range from 9 to 32 with a total of 19,007 records, and the fleet operated around 23°~31.5 °N, 119~127.5 °E. The number of vessels can be directly compared with the standard vessel (level 1) range from 2 (in 2004) to 19 (in 2009), while indirectly compared with the standard vessel (level 2) range from 0 (in 2003, 2005-2006 and 2013) to 9 (2010). Proportion of standardized vessels ranges from 44% (in 2004) to 90% (in 2010). The estimated fishing powers of each vessel ranged from 0.03 to 6.25. The adjusted CPUEs are lower than the nominal CPUE for at least 8 years during 2002-2013. The abundance trends are similar for the nominal and the adjusted CPUE: increased from 2002 to 2005, decreased from 2005 to 2008, and increased again after 2009. The catch data (in weight) are converted to catch in individuals by historical biological data and perform the depletion method. The catchability coefficients are highly variable annually (0.57 to 12.92). The annual fishing mortality (F) ranges from 1.50 (in 2009) to 15.75 (in 2011). The annual initial population size ranges from 0.76 million (in 2002) to 11.1 million (in 2010). The annual proportional escapement, assuming weekly natural mortality at 0.03, ranges from 36% (in 2006) to 96% (in 2008) with an average of 75%. The escapement biomass is 22,655.6 to 3,756,461.03 tons. These results suggest that the abundance of swordtip squid in the SECS was kept upper level, although limited number of sample vessel could hinder actual situation. Stock abundance and distribution pattern of short-lived species are vulnerable to environmental conditions, and usually response quickly. Therefore, to increase number of sample vessels and continue monitoring III variation in fleet and catch may improve the results of stock assessment for neritic squids which could support the basic information for strategies of fishing management planning.
Wan-Chieh, Wu, i 吳宛潔. "Study on Management and Job Performance of Abroad Employed Foreign Seafarers of Taiwan Deep-sea Squid Fishery". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/02763242537822860539.
Pełny tekst źródła國立高雄海洋科技大學
漁業生產與管理研究所
102
The amount of foreign seafarers has gradually increased in recent years. They are hired either based on Employment Service ACT or employed by the vessel owner himself, which means the fishery industries become more globalized. This phenomenon shows a remarkable trend that the foreign seafarers are more important. The results of this study were conducted from questioned and interviewed the boat owners about seafarers’ performance who worked on squid and saury boats. The conclusions reveal that the owners regard salary, efforts and obedience as the hiring factors, they are willing to offer proper accommodation and bonus if these employees meet anticipations as well. The Philippine, Indonesian and Vietnamese seafarers’ work attitude have significant difference on employment willingness. Setting a work performance standard not only can compare effectiveness of seafarers but also be able to realize what are the major hiring elements to reduce conflicts and arguments among seafarers. It provides a more stable and safe work environment on the sea for foreign seafarers.
Chu, Jackson Wing Four. "Influence of seasonally variable hypoxia on epibenthic communities in a coastal ecosystem, British Columbia, Canada". Thesis, 2016. http://hdl.handle.net/1828/7182.
Pełny tekst źródłaGraduate
0329
0416
0433
jwfchu@gmail.com
Ssemugabi, Samuel. "Development and validation of an integrated model for evaluating e-service quality, usability and user experience (e-SQUUX) of Web-based applications in the context of a University web portal". Thesis, 2019. http://hdl.handle.net/10500/26005.
Pełny tekst źródłaDevelopments in Internet technology and pervasive computing over the past two and half decades have resulted in a variety of Web-based applications (WBAs) that provide products and services to online users or customers. The Internet is used not only to transfer information via the web but is increasingly used to provide electronic services including business transactions, information-delivery and social networking, as well as e-government, e-health and e-learning. For such organisations, e-service quality, usability and user experience are considered to be critical determinants of their products’ or services’ success. Many studies to model these three concepts separately have been undertaken as part of broader studies of software quality or service quality modelling. However, to the current researcher’s knowledge, none of the studies have focussed on proposing an evaluation model that integrates and combines the three of them. This research is an effort to fill that gap. The primary purpose of this mixed-methods research was to develop a conceptual integrated model for evaluating e-service quality, usability and user experience (e-SQUUX) of WBAs and then contextualise it to evaluation of a University web portal (UWP). This was undertaken using an exploratory sequential research design. During a qualitative phase, an extensive extensive systematic literature review of 264 relevant sources relating to dimensions of e-service quality, usability and user experience, was undertaken to derive an integrated conceptual e-service quality, usability and user experience (e-SQUUX) Model for evaluating WBAs. The model was then empirically refined through a sequential series of validations, thus developing various versions of the e-SQUUX Model. First, it was content validated by a set of four expert reviewers. Second, during the quantitative phase, in the context of a University web portal, a questionnaire survey was conducted that included a comprehensive pilot study with 29 partipants, prior to the main survey. The main survey data from 174 particiapants was used to determine a validated model, using Exploratory factor analysis (EFA), followed by producing a structural model, using partial least square – structural equation modelling (PLS-SEM). This version consisted of the components of the final e-SQUUX Model. Consequently, the research enriches the body of knowledge on IS and HCI by providing the e-SQUUX Model as an evaluation tool. For designers, developers and managers of UWPs, the model serves as a customisable set of evaluation criteria and also provides specific recommendations for design. In line with the Exploratory sequential design of mixed methods research, the findings of the qualitative work in this research influenced the subsequent quantitative study, since the potential Likert-scale questionnaire items were derived from the definitions and meanings of the components that emanated from the qualitative phase of the study. Consequently, this research is an exemplar for developing an integrated evaluation model for specific facets or domains, and of its application in a particular context, in this case, a University web portal. Keywords: e-service quality, usability, user experience, evaluation model, integrated model, exploratory factor analysis, partial least square – structural equation modelling (PLS-SEM), mixed methods research, Exploratory sequential design, quantitative study, qualitative study, validation, Web-based applications, University web portal
Information System
Ph D. (Information Systems)