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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Organic iron requirements of gilthead sea bream (Sparus aurata)

Samartzis, Alexandros January 2014 (has links)
The aim of the current study was to determine the organic iron (Fe) requirements of gilthead sea bream (Sparus aurata). A total number of four experiments have been carried out each one for 12 weeks, in order to address and extend the knowledge on nutritional issues and challenges related with the culture of the gilthead sea bream in the Greek aquaculture industry and therefore enhance the fish health status under intensive culture conditions. These experiments aimed to determine the optimum level of organic Fe supplemented in commercial type diets of sea bream, the comparison between an organic Fe form and two inorganic Fe forms added in the diet of the fish, the effect of supplemented organic Fe on sea bream species exposed to oxygen deprivation stressors related to poor aquaculture husbandry practices and finally the interaction of organic Fe in the diet of sea bream with various levels of other trace minerals (Zn, Cu). The parameters evaluated were the growth performance of the fish, the Fe concentration in three selected tissues (the spleen, the liver and the muscle), the haematological status of the fish (the haematocrit, the red blood cell count, and the haemoglobin) and both the humoral and cellular immunology of the fish (the antibacterial activity of serum and the respiratory burst respectively). 150 mg/Kg of added organic Fe appears to be the recommended level as well as the minimum amount on fish exposed to overstocking conditions. The comparison between the two inorganic Fe forms (Ferrous Sulphate and Ferrous Carbonate) added in the diets show no significant effect on the fish. While, the fish fed the diets with 150 mg/Kg organic Fe and Cu levels lower that 5 mg/Kg had higher Hb values.
2

Purification and characterization of two isoforms of aldehyde dehydrogenase from the liver of black seabream Mylio macrocephalus.

January 2002 (has links)
by Tang Wai Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 91-110). / Abstracts in English and Chinese. / Acknowledgements / 論文摘要 / Abstract / Abbreviations / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Aldehyde Dehydrogenase Extended Family --- p.1 / Chapter 1.1.1 --- Phylogenetic Tree --- p.2 / Chapter 1.1.2 --- Physiological Functions --- p.4 / Chapter 1.1.3 --- Structural Conservations --- p.7 / Chapter 1.2 --- ALDH-1 and ALDH-2 --- p.9 / Chapter 1.3 --- Antiquitin --- p.11 / Chapter 1.4 --- Osmoregulation --- p.14 / Chapter 1.4.1 --- Osmoprotectant --- p.14 / Chapter 1.4.2 --- Betaine Aldehyde Dehydrogenase --- p.15 / Chapter 1.5 --- Objectives of the Present Study --- p.18 / Chapter Chapter 2 --- Purification and Characterization of Seabream ALDH-2 and Antiquitin --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials --- p.21 / Chapter 2.3 --- Methodology / Chapter 2.3.1 --- Preparation of Crude Tissue Extract --- p.22 / Chapter 2.3.2 --- Synthesis of α-Cyanocinnamate Sepharose --- p.22 / Chapter 2.3.3 --- Synthesis of p-Hydroxyacetophenone Sepharose --- p.23 / Chapter 2.3.4 --- Purification of ALDH-2 --- p.23 / Chapter 2.3.5 --- Purification of Antiquitin --- p.24 / Chapter 2.3.6 --- Enzyme and Protein Assays --- p.24 / Chapter 2.3.7 --- Electrophoretic Procedures / Chapter 2.3.7.1 --- Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) --- p.26 / Chapter 2.3.7.2 --- Native PAGE --- p.27 / Chapter 2.3.7.3 --- Isoelectric focusing (IEF) --- p.27 / Chapter 2.3.8 --- N-terminal Amino Acid Sequencing --- p.28 / Chapter 2.4 --- Results / Chapter 2.4.1 --- Tissue Distribution of ALDH --- p.29 / Chapter 2.4.2 --- Purification and Molecular Properties of ALDH-2 --- p.31 / Chapter 2.4.3 --- Kinetic Properties of ALDH-2 --- p.42 / Chapter 2.4.4 --- Purification and Molecular Properties of Antiquitin --- p.49 / Chapter 2.4.5 --- Kinetic Properties of Antiquitin --- p.54 / Chapter Chapter 3 --- Discussion / Chapter 3.1 --- Tissue Distribution --- p.66 / Chapter 3.2 --- N-terminal Amino Acid Sequencing --- p.67 / Chapter 3.3 --- Purification of Seabream ALDH --- p.68 / Chapter 3.3.1 --- Separation of Two ALDH isoforms --- p.69 / Chapter 3.3.2 --- Binding Affinity of α-Cyanocinnamate Sepharose --- p.70 / Chapter 3.3.3 --- Purification --- p.72 / Chapter 3.4 --- Electrophoretic Properties --- p.73 / Chapter 3.5 --- pH and Temperature Stability --- p.74 / Chapter 3.6 --- Substrate Specificity --- p.77 / Chapter 3.7 --- Possible Functions of Antiquitin --- p.80 / Chapter 3.8 --- Future Prospects --- p.84 / Chapter Chapter 4 --- Conclusion --- p.90 / Chapter Chapter 5 --- References --- p.91
3

Cloning, expression and crystallization of black seabream (acanthopagrus schlegeli) antiquitin. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Antiquitin (ATQ) belongs to the superfamily of aldehyde dehydrogenase (ALDH). It is an evolutionarily conserved protein as shown from its high amino acid sequence identity between human and its plant counterparts. Therefore, ATQ is believed to play an important physiological role. Until now, however, studies on ATQ are limited and its cellular function is uncertain. Recently, we have first demonstrated the aldehyde oxidizing ability of ATQ purified from the liver of black seabream (Acanthopagrus schlegeli). To further investigate this protein, different attempts have been made. / Recombinant ATQ has been successfully expressed in E. coli. Kinetics studies showed that it possessed similar characteristics with its native enzyme. The recombinant protein was produced in large amount for protein crystallization. Crystal of ATQ was obtained and its X-ray structure was solved to 2.8 A in complex with NAD+. Tetrameric ATQ was a dimer of dimer. Three domains can be found in the subunit structure of ATQ, the NAD+-binding domain, catalytic domain and oligomerization domain. In each of the NAD+-binding domain, one molecule of NAD + could be found. The overall structure of ATQ was similar to other tetrameric ALDHs, but the coenzyme binding was in a single "hydride transfer" conformation and the density was well-defined which was contrast to most ALDH structures. Structural study of the substrate-binding pocket explained the failure of ATQ in oxidizing several aldehydes which is specific to certain members of ALDH. / The ATQ full-length cDNA of black seabream was obtained. It consisted of 2309 by with a 153 nucleotide long 5' UTR, and a 209 nucleotide long 3' UTR. An ORF of 1533 by which encoded a protein with 511 amino acids was found. This putative protein showed the highest of 87% sequence identity with zebrafish ATQ, and ∼60% with plant ATQs. Tissue distribution was studied by RT-PCR. A high level of mRNA expression was observed in liver and kidney. Subcellular localization study using green fluorescent protein (GFP) fusion protein showed that ATQ was expressed in cytoplasm. However, another in-frame initiation methionine (M1) was found 31 residues before this generally accepted methionine (M2). Both iPSORT analysis and experimental studies using GFP fusion protein indicated that the 31 amino acid peptide contained a mitochondrial-targeting signal. / Tang Wai Kwan. / "July 2005." / Adviser: Fong Wing Ping. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3603. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 130-145). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
4

Mechanisms of virulence associated with thermolabile hemolysin (TLH) from Vibrio alginolyticus on erythrocytes of silver sea bream, Sparus sarba.

January 2011 (has links)
Wong, Sze Ki. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 87-106). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract in Chinese --- p.iv / Table of contents --- p.V / List of figures --- p.ix / List of abbreviations --- p.X / Chapter Chapter 1. --- General introduction --- p.1 / Chapter Chapter 2. --- Literature review --- p.6 / Chapter 2.1. --- Pathogenic mechanisms of Vibrio species in fish --- p.7 / Chapter 2.1.1. --- Introduction --- p.7 / Chapter 2.1.2. --- Adhesion --- p.7 / Chapter 2.1.3. --- Invasion --- p.8 / Chapter 2.1.4. --- Proliferation --- p.9 / Chapter 2.2. --- Vibrio virulence factors --- p.12 / Chapter 2.2.1. --- Introduction --- p.12 / Chapter 2.2.2. --- Hemolysin --- p.12 / Chapter 2.2.3. --- Protease --- p.14 / Chapter 2.2.4. --- Siderophore --- p.15 / Chapter 2.2.5. --- Lipopolysaccharide --- p.15 / Chapter 2.3. --- General apoptotic pathways --- p.17 / Chapter 2.3.1. --- Introduction --- p.17 / Chapter 2.3.2. --- Extrinsic apoptotic pathway --- p.17 / Chapter 2.3.2.1. --- Death receptor signaling apoptosis --- p.17 / Chapter 2.3.2.1.1. --- Fas signaling pathway --- p.18 / Chapter 2.3.2.1.2. --- TNF-R1 signaling pathway --- p.19 / Chapter 2.3.2.1.3. --- TRAIL receptors signaling pathway --- p.20 / Chapter 2.3.2.2. --- Growth factor receptor signaling apoptosis --- p.21 / Chapter 2.3.3. --- Intrinsic apoptotic pathway --- p.21 / Chapter 2.3.3.1. --- Mitochondrial apoptotic pathway --- p.21 / Chapter 2.3.3.1.1. --- Cyto c --- p.22 / Chapter 2.3.3.1.2. --- Smac/DIABLO --- p.22 / Chapter 2.3.3.1.3. --- Omi/HtrA2 --- p.22 / Chapter 2.3.3.1.4. --- AIF and endo G --- p.23 / Chapter 2.3.3.1.5. --- Bcl-2 family --- p.23 / Chapter 2.3.3.1.6. --- Mitochondrial membrane permeabilization (MMP) --- p.23 / Chapter 2.3.3.2. --- p53-regulated apoptotic pathway --- p.24 / Chapter 2.3.3.3. --- Endoplasmic reticulum (ER) stress-induced apoptotic pathway --- p.25 / Chapter 2.4. --- Membrane vesiculation in erythrocytes --- p.26 / Chapter 2.4.1. --- Introduction --- p.26 / Chapter 2.4.2. --- Induction of vesiculation --- p.26 / Chapter 2.4.3. --- Contents of vesicles --- p.28 / Chapter 2.4.4. --- Mechanisms involved during vesiculation --- p.29 / Chapter 2.4.5. --- Correlation between apoptosis and membrane vesiculation in erythrocytes --- p.31 / Chapter 2.4.6. --- Reasons for vesiculation --- p.31 / Chapter Chapter 3. --- "Induction of apoptosis by Vibrio alginolyticus thermolabile hemolysin (TLH) in blood cells of silver sea bream, Sparus sarba" --- p.33 / Chapter 3.1. --- Abstract --- p.34 / Chapter 3.2. --- Introduction --- p.34 / Chapter 3.3. --- Materials and methods --- p.36 / Chapter 3.3.1. --- Experimental fish --- p.36 / Chapter 3.3.2. --- Whole blood preparation --- p.37 / Chapter 3.3.3. --- Preparation of V. alginolyticus TLH --- p.37 / Chapter 3.3.4. --- "Caspase-3, -8, -9/6 fluorescent assay" --- p.38 / Chapter 3.3.5. --- TUNEL assay --- p.39 / Chapter 3.3.6. --- Apoptotic DNA ladder assay --- p.40 / Chapter 3.3.7. --- Statistical analysis --- p.41 / Chapter 3.4. --- Results --- p.42 / Chapter 3.4.1. --- "Increase of caspase-3, -8, -9/6 activities" --- p.42 / Chapter 3.4.2. --- Detection of DNA fragmentation by TUNEL assay --- p.44 / Chapter 3.4.3. --- Detection of DNA fragmentation by apoptotic DNA ladder assay --- p.44 / Chapter 3.5. --- Discussion --- p.46 / Chapter Chapter 4. --- "Occurrence of membrane vesiculation, apoptosis and post-apoptotic necrosis after exposure to Vibrio alginolyticus thermolabile hemolysin (TLH) in erythrocytes of silver sea bream, Sparus sarba" --- p.51 / Chapter 4.1. --- Abstract --- p.52 / Chapter 4.2. --- Introduction --- p.52 / Chapter 4.3. --- Materials and methods --- p.54 / Chapter 4.3.1. --- Experimental fish --- p.54 / Chapter 4.3.2. --- Whole blood preparation --- p.54 / Chapter 4.3.3. --- Preparation of V. alginolyticus TLH --- p.55 / Chapter 4.3.4. --- Light microscopy --- p.55 / Chapter 4.3.5. --- Transmission electron microscopy (TEM) --- p.56 / Chapter 4.3.6. --- Measurement of membrane vesiculation - acetylcholinesterase (AChE) assay --- p.56 / Chapter 4.3.7. --- Measurement of necrosis - hemoglobin colorimetric assay --- p.57 / Chapter 4.3.8. --- Apoptotic DNA ladder assay --- p.58 / Chapter 4.3.9. --- Flow cytometry --- p.59 / Chapter 4.3.10. --- Statistical analysis --- p.59 / Chapter 4.4. --- Results --- p.60 / Chapter 4.4.1. --- Ultrastructural changes in red blood cells after exposure to TLH --- p.60 / Chapter 4.4.2. --- Changes of cell population in size and granularity after exposure of TLH --- p.67 / Chapter 4.4.3. --- Effect of TLH dosage on necrosis and DNA fragmentation --- p.72 / Chapter 4.4.4. --- "Occurrence of membrane vesiculation, necrosis and DNA fragmentation in cells exposed to TLH" --- p.72 / Chapter 4.5. --- Discussion --- p.76 / Chapter Chapter 5. --- General conclusions --- p.82 / References --- p.87
5

Application of genome editing to marine aquaculture as a new breeding technology / ゲノム編集技術を用いた海産養殖魚の品種改良法の開発

Kishimoto, Kenta 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21827号 / 農博第2340号 / 新制||農||1067(附属図書館) / 学位論文||H31||N5199(農学部図書室) / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 佐藤 健司, 准教授 豊原 治彦, 准教授 田川 正朋 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
6

ÓLEOS ESSENCIAIS COMO ANESTÉSICOS PARA PEIXES: ASPECTOS BIOQUÍMICOS E MOLECULARES / ESSENTIAL OILS AS ANESTHETICS FOR FISH: BIOCHEMICAL AND MOLECULAR ASPECTS

Toni, Cândida 15 January 2015 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The essential oil (EOs) extracted from plants Hesperozygis ringens and Lippia alba possess anesthetic and sedative properties and is an alternative to traditional anesthetics used in aquaculture for ease of handling and/or reduce stress. In this sense, the study aimed to investigate the effects of these EOs on the physiology of fish, through physiological, biochemical and endocrine indicators. In the article 1 was determined (a) the anesthetic activity of the EOs of H. ringens (EOHR) and L. alba (EOLA) and (b) its effects on silver catfish (Rhamdia quelen) after induction and recovery from anesthesia. Fish were subjected to one of the following treatments for each EO: basal group, control or anesthetized (150, 300 or 450 uL L-1 EO), evaluating the ventilatory rate (VR) during the induction period and thereafter transferred to anesthetics-free tanks for recovery from anesthesia. At 0, 15, 30, 60 and 240 min of recovery, samples of plasma and gills were collected to measure metabolic indicators and ionregulatory enzymes, respectively. In the article 2, the effects of prolonged exposure to low EOHR concentrations were studied on silver catfish. After 6 h of exposure to 0 (control), 30 or 50 uL L-1 EOHR added to water, it was analyzed: VR, metabolic indicators of stress in plasma, enzyme activity in liver, and expression of pituitary hormones (growth hormone - GH, prolactin - PRL and somatolactina - SL). In the manuscript, (a) evaluated the effectiveness of anesthesia EOLA on gilthead sea bream (Sparus aurata) and (b) we investigated the effects of 35 uL L-1 EOLA and 2-phenoxyethanol (2-PHE) on the stress response in gilthead sea bream undergoing persecution. After 4 h of exposure, the plasma was sampled (for the determination of cortisol, metabolites and osmolality), brain and pituitary (to evaluate the expression of endocrine indicators). In the article 1, anesthesia with EOs caused changes in some parameters measured in silver catfish, but did not prevent the restoration of most of the indicators assessed after 240 min of recovery. In the article 2, 50 uL L-1 EOHR led to an increase of glucose, lactate, protein and osmolality, as well as an increase in metabolic enzyme activity and reduced expression of GH and SL. In the manuscript, gilthead sea bream exposed to EOLA, stressed or not, exhibited higher levels of cortisol, glucose, lactate and osmolality. EOLA exposure added to the stress reduced the expression levels of CRH-BP (corticotropin releasing hormone bound to protein). PRL expression was reduced in the stressed control group and after exposure to EOLA and 2-PHE in fish not stressed. Higher expression of pro-opiomelanocortin (POMC) "a" and "b" were observed in fish stressed and exposed to EOLA and 2-PHE, respectively. We conclude that: (1) the EOLA is more efficient for silver catfish that EOHR in anesthesia concentrations; (2) for sedating the fish, it is recommended 30 uL EOHR L-1 (or less); (3) the EOLA was effective as an anesthetic for gilthead sea bream at 100-300 uL L-1, but for 4 h exposure, the 2-PHE was more effective in preventing the stress response. / Os óleos essenciais (OEs) extraídos das plantas Hesperozygis ringens e Lippia alba possuem propriedades anestésica e sedativa, constituindo uma alternativa aos anestésicos tradicionalmente usados em aquicultura para facilitar o manejo e/ou reduzir o estresse. Neste sentido, o estudo teve por objetivo investigar os efeitos desses OEs sobre a fisiologia de peixes, através de indicadores fisiológicos, bioquímicos e endócrinos. No artigo 1 determinou-se (a) a atividade anestésica dos OEs de H. ringens (OEHR) e L. alba (OELA) e (b) seus efeitos em jundiá (Rhamdia quelen) depois da indução e recuperação da anestesia. Os peixes foram submetidos a um dos seguintes tratamentos para cada OE: grupo basal, controle ou anestesiado (150, 300 ou 450 μL L-1 OE), avaliando-se a taxa ventilatória (TV) durante o período de indução e, posteriormente, transferidos para aquários sem anestésicos para recuperação da anestesia. Nos tempos 0, 15, 30, 60 e 240 min de recuperação foram realizadas amostragens de plasma e brânquias para medir indicadores metabólicos e enzimas ionorregulatórias, respectivamente. No artigo 2, os efeitos da exposição prolongada de jundiás a baixas concentrações do OEHR foram estudados. Após 6 h de exposição a 0 (controle), 30 ou 50 μL L-1 OEHR adicionado à água, analisou-se: TV, indicadores metabólicos e de estresse em plasma, atividade enzimática em fígado e expressão de hormônios hipofisários (hormônio do crescimento - GH, prolactina - PRL e somatolactina - SL). No manuscrito (a) avaliou-se a eficácia anestésica do OELA em dourada (Sparus aurata) e (b) investigaram-se os efeitos de 35 μL L-1 de OELA e 2-fenoxietanol (2-PHE) sobre a resposta ao estresse em douradas submetidos à perseguição. Após 4 h de exposição, foram amostrados plasma (para determinação dos níveis de cortisol, metabólitos e osmolalidade), cérebro e hipófise (para avaliar a expressão de indicadores endócrinos). No artigo 1, a anestesia com os OEs provocou alterações em alguns parâmetros medidos em jundiás, mas não impediu a restauração da maioria dos indicadores avaliados após 240 min de recuperação. No artigo 2, 50 μL L-1 do OEHR provocou a elevação dos níveis de glicose, lactato, proteína e osmolalidade, bem como aumento na atividade de enzimas metabólicas e redução na expressão do GH e SL. No manuscrito, douradas expostos ao OELA, estressados ou não, exibiram maiores níveis de cortisol, glicose, lactato e osmolalidade. A exposição ao OELA somado ao estresse reduziu os níveis de expressão de CRH-BP (hormônio liberador de corticotrofina ligado à proteína). A expressão de PRL foi reduzida no grupo controle estressado e após a exposição ao OELA e 2-PHE em peixes não estressados. Maiores expressões de pro-opiomelanocortina (POMC) a e b foram observadas em peixes estressados e expostos ao OELA e 2-PHE, respectivamente. Conclui-se que: (1) o OELA é mais eficiente para jundiás que o OEHR em concentrações para anestesia; (2) para sedar os peixes, recomenda-se 30 μL L-1 do OEHR (ou menos); (3) o OELA foi eficaz como anestésico para dourada entre 100-300 μL L-1, mas para 4 h de exposição o 2-PHE foi mais eficiente em prevenir a resposta ao estresse.
7

ANÁLISIS DE LA SITUACIÓN ECONÓMICA-FINANCIERA DEL SECTOR PRODUCTOR DE LA DORADA (Sparus aurata L.), LUBINA (Dicentrarchus labrax L.) Y CORVINA (Argyrosomus regius A.), EN EL LITORAL MEDITERRANEO ESPAÑOL

BENITO ALAS, FERNANDO 05 April 2016 (has links)
[EN] The state of the Spanish aquaculture Sea bream, Sea bass and Meagre produced in fish farms in the Spanish Mediterranean coast is analyzed setting as objective the analysis of the economical and financial situation of companies in the sector to characterize the successful companies. For this project a study was made during the period from 2002 to 2011, on the period before the economical crisis (2002-2007) and also during the crisis (2007-2011), to interpret the evolution of the companies from the financial and economical information extracted from their financial statements filed with the Companies Registry and are supplied by the SABI database. Economic and financial ratios of the sample aquaculture companies located in the Mediterranean coast examines representing 63% (2007), production of Sea bream, Sea bass and Meagre in Spain using statistical correlation analysis, principal components and cluster group that have allowed companies based on their financial situation. The combination of the economic and financial ratios to define a "Success Rate" of companies, it helps to know the status of each within the sector in relation to other companies, from assessing economical and financial variables if the steps taken leading to success or failure and thus becoming a key tool in making decisions at the enterprise level. The results indicate that only companies with high volume production or small well-managed companies have been able to withstand periods of economical crisis. Likewise, annual ratios of companies with best results in each period are analyzed to define the business model of success that is configured as necessary reference in the process of management in the aquaculture sector. During this time the evolution of the sales prices of the different aquatic species in Spain is also studied, from data the wholesale markets, the price observatory of the Ministerio de Agricultura, Alimentación y Medio Ambiente, and Mis Peces portal, as the price is vital for good economical performance, along with a sound technical and economical-financial management. The concept of "success rate" is new in this sector, it has developed a valid tool for studying the situation of companies within the aquaculture sector from the financial economic variables, easily accessible to the Financial Statements proceed with a reasonable degree of reliability compared to other more subjective variables. / [ES] Se analiza el estado de la acuicultura española de la dorada, lubina y corvina producidas en granjas marinas en el litoral del mar Mediterráneo español, fijándose como objetivo el análisis de la situación económico-financiera de las empresas del sector para caracterizar a las empresas de éxito. Para ello se realiza un estudio durante el periodo desde el año 2002 hasta el 2011, espacio de tiempo previo a la crisis económica (2002-2007) y durante la crisis (2007-2011), para analizar la evolución de las empresas a partir de la información económica financiera extraída de sus estados contables depositados en el Registro Mercantil y que son suministrados por la Base de Datos SABI. Se examinan los ratios económico-financieros de la muestra tomada de empresas de acuicultura ubicadas en el litoral Mediterráneo que representan el 63 % (2007), de la producción de dorada, lubina y corvina en España mediante análisis estadísticos de correlación, componentes principales y clúster, que han permitido agrupar a las empresas en función de su situación económico-financiera. La combinación de los ratios económico-financieros permite definir un "Índice de Éxito" de las empresas, que ayuda a conocer la situación de cada una de ellas dentro del sector en relación al resto de empresas, evaluando a partir de variables económico financieras si la gestión realizada lleva al éxito o al fracaso y convirtiéndose así en una herramienta clave en la toma de decisiones a nivel empresarial. Los resultados indican que solo empresas con gran volumen de producción o pequeñas empresas bien gestionadas, han sido capaces de soportar el periodo de crisis económica. Asimismo, se analizan los ratios anuales de las empresas con mejores resultados en cada periodo para definir el modelo de empresa de éxito que se configura como referencia necesaria en el proceso de gestión en el sector de la acuicultura. Durante este tiempo también se estudia la evolución de los precios de venta de las diferentes especies acuícolas en España, a partir de los datos de la Red de Mercas, el Observatorio de Precios del Ministerio de Agricultura, Alimentación y Medio Ambiente, y el portal Mis Peces, pues el precio de venta es vital para obtener buenos resultados económicos, además de una buena gestión técnica y económico-financiera. El concepto del "Índice de Éxito" resulta novedoso en este sector, pues se ha desarrollado una herramienta válida para estudiar la situación de las empresas dentro del sector acuícola a partir de las variables económicas financieras, fácilmente accesibles al proceder de los Estados Contables y con un razonable grado de fiabilidad frente a otras variables más subjetivas. / [CAT] S'analitza l'estat de l'aqüicultura espanyola de l'orada, llobarro i corbina produïdes en granges marines al litoral del mar Mediterrani espanyol, establint com a objectiu l'anàlisi de la situació económica i financera de les empreses del sector per tal de caracteritzar les empreses d'èxit. Per a això, es realitza un estudi durant el període des de l'any 2002 fins al 2011, que inclou un espai de temps previ a la crisi econòmica (2002-2007) i altre durant la crisi (2007-2011), per analitzar l'evolució de les empreses a partir de la informació econòmica-financera extreta dels seus estats comptables dipositats en el Registre Mercantil, i que són subministrats per la base de dades SABI. S'examinen les ràtios econòmicofinanceres d'un conjunt d'empreses d'aqüicultura ubicades al litoral Mediterrani, que representen el 63% (2007), de la producció d'orada, llobarro i corbina a Espanya, mitjançant diferents anàlisis estadístics, com l'anàlisi de correlació, components principals i clúster, que han permès agrupar les empreses en funció de la seva situació economicofinancera. La combinació de les ràtios economicofinanceres permet definir un "Índex d'Èxit" de les empreses, que ajuda a conèixer la situació de cadascuna d'elles dins del sector en relació a la resta d'empreses, avaluant a partir de variables econòmico-financeres si la gestió realitzada duu a l'èxit o al fracàs, convertint-se així en una eina clau en la presa de decisions a nivell empresarial. Els resultats indiquen que només empreses amb gran volum de producción, o xicotetes empreses ben gestionades, han estat capaços de suportar el període de crisi econòmica. Així mateix, s'analitzen les ràtios anuals de les empreses amb millors resultats en cada període per definir el model d'empresa d'èxit, esdevenenint aquest una referència necessària en el procés de gestió en el sector de l'aqüicultura. També s'estudia l'evolució dels preus de venda de les diferents espècies aqüícoles a Espanya durant el període entre 2002 i 2011, a partir de les dades de la Red de Mercas, l'Observatori de Preus del Ministeri d'Agricultura, Alimentació i Medi Ambient i el portal Mis Peces, ja que el preu de venda és vital per obtenir bons resultats econòmics, a més de la realització d'una bona gestió tècnica i econòmicofinancera. El concepte d'"Índex d'Èxit" és nou en aquest sector, i representa una eina vàlida per estudiar la situació de les empreses dins del sector aqüícola a partir de les variables econòmico-financeres, fàcilment accessibles ja que procedeixen dels estats comptables, i amb un raonable grau de fiabilitat en comparació amb altres variables més subjectives. / Benito Alas, F. (2016). ANÁLISIS DE LA SITUACIÓN ECONÓMICA-FINANCIERA DEL SECTOR PRODUCTOR DE LA DORADA (Sparus aurata L.), LUBINA (Dicentrarchus labrax L.) Y CORVINA (Argyrosomus regius A.), EN EL LITORAL MEDITERRANEO ESPAÑOL [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62187 / TESIS
8

Evaluation of Organic Plant and Animal Ingredients for Fish Feeding

Tefal, Eslam Hamdy Taha 25 April 2024 (has links)
Tesis por compendio / [ES] La acuicultura orgánica o ecológica está ganando popularidad a medida que los consumidores se vuelven más conscientes de las prácticas de producción alimentaria sostenibles y respetuosas con el medio ambiente. Las dietas con ingredientes orgánicos son un componente esencial de la acuicultura ecológica. Estas dietas utilizan ingredientes orgánicos y formulaciones específicas para promover una producción de animales acuáticos más saludable y respetuosa con el medio ambiente. Se alinean con los principios de la agricultura orgánica, minimizan el uso de productos químicos sintéticos y buscan producir productos del mar más saludables y ambientalmente responsables. La presente tesis de doctorado reúne cuatro estudios distintos con el objetivo de avanzar en nuestra comprensión de la integración de nuevos ingredientes orgánicos en las dietas de acuicultura y sus efectos en diversas especies, centrándose en la dorada (Sparus aurata), la lubina (Dicentrarchus labrax) y la trucha arcoíris (Oncorhynchus mykiss). Estos estudios exploran el crecimiento, la composición corporal, la utilización del alimento, la digestibilidad, las respuestas histológicas y la composición de la microbiota al incorporar alimentos e ingredientes orgánicos novedosos. En el primer estudio, se investigó el efecto del alimento eco-orgánico en el crecimiento, la eficiencia nutricional, la utilización del alimento y la composición corporal de la dorada. Se ensayaron seis dietas, incluyendo una dieta de control (CONT) sin ingredientes orgánicos, cuatro dietas con 100% de ingredientes orgánicos (subproducto de trucha - TRO, subproducto de lubina - SBS, subproductos avícolas - POU y mezcla - MIX), y una dieta de control orgánico (ORG) con ingredientes orgánicos y 30% de harina de pescado. En el experimento, de 70 días de duración, se alimentó a los peces dos veces al día, comenzando con un peso inicial de 60.5 g. Los resultados revelaron que las tasas de crecimiento más altas se observaron en peces alimentados con las dietas ORG y CONT que contenían harina de pescado. Por el contrario, la dieta POU mostró la tasa de crecimiento más baja, la tasa de supervivencia más baja y el mayor índice de conversión alimentaria (FCR). La eficiencia de aminoácidos esenciales fue generalmente alta en peces alimentados con las dietas ORG y CONT, con diferencias notables en la eficiencia de retención de ácidos grasos en todas las dietas. La dieta CONT mostró la mayor eficiencia de retención, seguida por la dieta ORG. Sin embargo, la tasa de conversión económica fue menor para CONT, SBS, TRO y MIX. En resumen, el uso de dietas orgánicas de origen animal afectó el rendimiento de crecimiento de la Dorada, con un potencial prometedor a pesar de las variaciones en las tasas de conversión económica entre diferentes dietas. En el segundo estudio, se investigó durante 120 días la utilización de nuevos ingredientes orgánicos para alimentar a la dorada de 93 ± 3.82 g de pesos inicial, centrándose en el crecimiento, los parámetros nutricionales, la digestibilidad y la histología. Se probaron cuatro dietas: una dieta de control orgánico (CON) y tres dietas con 100% de materiales orgánicos - subproducto de trucha arcoíris (TRO), subproducto de cerdo ibérico (IBE) y harina de insectos como fuente de proteínas (INS). Al final del experimento, los peces alimentados con la dieta CON mostraron el mayor peso, sin diferencia significativa entre las dietas experimentales. El contenido de proteínas crudas fue mayor en los peces alimentados con las dietas TRO e INS, mientras que el mayor valor de grasa cruda se observó en la dieta CON. Los peces alimentados con las dietas IBE e INS demostraron una alta digestibilidad, y excepto para el aminoácido esencial metionina (Met), la eficiencia de retención no mostró diferencias estadísticas. IBE tuvo la mayor tasa de hidrólisis entre las dietas. A pesar de las diferencias significativas en la dieta, la dorada mantuvo una morfología hepática típicamente saludable. Si / [CA] L'acuicultura orgànica o ecològica està guanyant popularitat a mesura que els consumidors es tornen més conscients de les pràctiques de producció alimentària sostenibles i respectuoses amb el medi ambient. Les dietes amb ingredients orgànics són un component essencial de l'acuicultura ecològica. Aquestes dietes utilitzen ingredients orgànics i formulacions específiques per promoure una producció d'animals aquàtics més saludable i respectuosa amb el medi ambient. Es alineen amb els principis de l'agricultura orgànica, minimitzen l'ús de productes químics sintètics i busquen produir productes del mar més saludables i ambientalment responsables. Aquesta tesi de doctorat reuneix quatre estudis diferents amb l'objectiu d'avançar en la nostra comprensió de la integració de nous ingredients orgànics a les dietes d'acuicultura i els seus efectes en diverses espècies, centrant-se en la dorada (Sparus aurata), la llobina (Dicentrarchus labrax) i la truita arc de Sant Martí (Oncorhynchus mykiss). Aquests estudis exploren el creixement, la composició corporal, la utilització dels aliments, la digestibilitat, les respostes histològiques i la composició de la microbiota en incorporar aliments i ingredients orgànics innovadors. En el primer estudi, es va investigar l'efecte de l'aliment eco-orgànic en el creixement, l'eficiència nutricional, la utilització dels aliments i la composició corporal de la dorada. Es van provar sis dietes, incloent una dieta de control (CONT) sense ingredients orgànics, quatre dietes amb 100% d'ingredients orgànics (subproducte de truita - TRO, subproducte de llobina - SBS, subproductes avícoles - POU i barreja - MIX), i una dieta de control orgànica (ORG) amb ingredients orgànics i 30% de farina de peix. En l'experiment, de 70 dies de durada, es va alimentar els peixos dues vegades al dia, començant amb un pes inicial de 60,5 g. Els resultats van revelar que les taxes de creixement més altes es van observar en peixos alimentats amb les dietes ORG i CONT que contenien farina de peix. Per contra, la dieta POU va mostrar la taxa de creixement més baixa, la taxa de supervivència més baixa i el major índex de conversió alimentària (FCR). L'eficiència dels aminoàcids essencials va ser generalment alta en peixos alimentats amb les dietes ORG i CONT, amb diferències notables en l'eficiència de retenció d'àcids grassos en totes les dietes. La dieta CONT va mostrar la major eficiència de retenció, seguida per la dieta ORG. No obstant això, la taxa de conversió econòmica va ser menor per a CONT, SBS, TRO i MIX. En resum, l'ús de dietes orgàniques d'origen animal va afectar el rendiment de creixement de la Dorada, amb un potencial prometedor malgrat les variacions en les taxes de conversió econòmica entre diferents dietes. En el segon estudi, es va investigar durant 120 dies la utilització de nous ingredients orgànics per alimentar la dorada amb un pes inicial d'aproximadament 93 ± 3.82 g, centrant-se en el creixement, els paràmetres nutricionals, la digestibilitat i la histologia. Es van provar quatre dietes: una dieta de control orgànica (CON) i tres dietes amb 100% de materials orgànics - subproducte de truita arc de Sant Martí (TRO), subproducte de porc ibèric (IBE) i farina d'insectes com a font de proteïnes (INS). Al final de l'experiment, els peixos alimentats amb la dieta CON van mostrar el major pes, sense diferència significativa entre les dietes experimentals. El contingut de proteïnes brutes va ser major en els peixos alimentats amb les dietes TRO e INS, mentre que el major valor de greix brut es va observar en la dieta CON. Els peixos alimentats amb les dietes IBE e INS van demostrar una alta digestibilitat, i excepte per a l'aminoàcid essencial metionina (Met), l'eficiència de retenció no va mostrar diferències estadístiques. IBE va tenir la major taxa d'hidròlisi entre les dietes. Malgrat les diferències significatives a la dieta, la dorada va mantenir una morfologia hepàtica típicament saludable. No obstant a / [EN] The organic or ecological aquaculture is gaining popularity as consumers become more aware of sustainable and environmentally friendly food production practices. Diets with organic ingredients are an essential component of ecological aquaculture. These diets use organic ingredients and specific formulations to promote healthier and environmentally friendly aquatic animal production. They align with the principles of organic farming, minimize the use of synthetic chemicals, and aim to produce healthier and environmentally responsible seafood products. This doctoral thesis comprises four distinct studies with the aim of advancing our understanding of the integration of new organic ingredients in aquaculture diets and their effects on various species, focusing on gilthead sea bream (Sparus aurata), European sea bass (Dicentrarchus labrax), and rainbow trout (Oncorhynchus mykiss). These studies explore growth, body composition, feed utilization, digestibility, histological responses, and microbiota composition when incorporating novel organic foods and ingredients. In the first study, the effect of eco-organic feed on the growth, nutritional efficiency, feed utilization, and body composition of gilthead sea bream was investigated. Six diets were tested, including a control diet (CONT) without organic ingredients, four diets with 100% organic ingredients (rainbow trout byproduct - TRO, European sea bass byproduct - SBS, poultry byproducts - POU, and a mixture - MIX), and an organic control diet (ORG) with organic ingredients and 30% fish meal. In the 70-day experiment, fish were fed twice a day, starting with an initial weight of 60.5 g. The results revealed that the highest growth rates were observed in fish fed the ORG and CONT diets containing fish meal. In contrast, the POU diet showed the lowest growth rate, the lowest survival rate, and the highest feed conversion ratio (FCR). The efficiency of essential amino acids was generally high in fish fed ORG and CONT diets, with notable differences in fatty acid retention efficiency in all diets. The CONT diet showed the highest retention efficiency, followed by the ORG diet. However, the economic conversion rate was lower for CONT, SBS, TRO, and MIX. In summary, the use of organic diets of animal origin affected the growth performance of gilthead sea bream, with promising potential despite variations in economic conversion rates between different diets. In the second study, the use of new organic ingredients to feed gilthead sea bream with an initial weight of 93 ± 3.82 g was investigated for 120 days, focusing on growth, nutritional parameters, digestibility, and histology. Four diets were tested: an organic control diet (CON) and three diets with 100% organic materials - rainbow trout byproduct (TRO), Iberian pork byproduct (IBE), and insect meal as a protein source (INS). At the end of the experiment, fish fed the CON diet showed the highest weight, with no significant difference between the experimental diets. The crude protein content was higher in fish fed TRO and INS diets, while the highest crude fat value was observed in the CON diet. Fish fed IBE and INS diets demonstrated high digestibility, and except for the essential amino acid methionine (Met), retention efficiency showed no statistics differences. IBE had the highest hydrolysis rate among the diets. Despite significant differences in diet, gilthead sea bream maintained a typically healthy liver morphology. However, fish fed TRO and INS diets showed shorter measurements in the distal intestine. In conclusion, the complete replacement of fish meal with organic materials, including rainbow trout byproducts, Iberian pork byproducts, and insect meal, offers several benefits in terms of digestibility, histology, and growth performance, promoting sustainable and healthy aquaculture practices. The third study aimed to evaluate the feasibility of using various organic proteins in the diet of European sea bass. Juvenile sea b / The first author was supported by a complete grant from the Ministry of Higher Education of the Arab Republic of Egypt and the research project had been developed with the collaboration of the Biodiversity Foundation (Spanish Ministry for Ecological Transition and the Demographic Challenge), through the Pleamar Program, co-financed by the European Maritime and Fisheries Fund (EMFF). / Tefal, EHT. (2024). Evaluation of Organic Plant and Animal Ingredients for Fish Feeding [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/203838 / Compendio

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