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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

Lesões sugestivas de infecção hipodermal e necrose hematopoiética em camarão marinho, relacionadas com variáveis de cultivo

BEZERRA, Suely Santos 23 February 2007 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-02-22T12:37:59Z No. of bitstreams: 1 Suely Santos Bezerra.pdf: 418523 bytes, checksum: 6cbf43e2cf1c398824dd661f7ea8c038 (MD5) / Made available in DSpace on 2017-02-22T12:37:59Z (GMT). No. of bitstreams: 1 Suely Santos Bezerra.pdf: 418523 bytes, checksum: 6cbf43e2cf1c398824dd661f7ea8c038 (MD5) Previous issue date: 2007-02-23 / It can be observed nowadays that the increase in the commercial shrimp produc-tion occurs concomitantly with an enhancement of the incidence of diseases. These last ones can cause innumerable damages to the shrimp farmers in the whole world. Amongst these diseases, it can be distinguished the Infectious Hypodermal and Hema-topoietic Necrosis (IHHN), with viral etiology, that can be characterized by not causing great mortality, but body deformities. In addition to this, it frequently leads shrimp to heterogenic growth. For viruses diagnosis histology is an efficient tool, allowing the verification of the health of these crustaceans. This study aimed the observation of the occurrence of IHHN characteristic histopatologic injuries in Litopenaeus vannamei, and its relation with parameters of culture of marine shrimp farms in the state of Per-nambuco. After multiple regression statistic analysis it could be concluded that the tem-perature of the water of the pound and its oxygen availability are narrowly related with the occurrence of those histopatologic injuries. / Ao mesmo tempo em que crescem os cultivos comerciais de camarão, observa-se o aumento da incidência de enfermidades que podem causar inúmeros prejuízos aos carcinicultores em todo o mundo. Dentre essas enfermidades, destaca-se a Infecção Hi-podermal e Necrose Hematopoiética (IHHN), de etiologia viral que, embora não cause grandes taxas de mortalidade, produz retardo no desenvolvimento e deformidades nos camarões. Para o diagnóstico dessa virose a histologia tem sido uma ferramenta bastante eficiente e que permite maior monitoramento da sanidade desses crustáceos. Desta for-ma, objetivou-se estudar a IHHN em Litopenaeus vannamei relacionando lesões histo-patológicas características e sua relação com variáveis de cultivo. Com base em regres-sões múltiplas conclui-se que existe uma alta relação entre as variáveis de cultivo tem-peratura e oxigênio e a ocorrência destas lesões.
2

Influ?ncia de fatores ambientais na incid?ncia do v?rus da infec??o hipodermal e necrose hematopoi?tica (IHHNV) no camar?o Litopenaeus vannamei cultivado em fazendas do Estado do Rio Grande do Norte (RN)

Silva, Cim?ria Porf?rio Rodrigues de Oliveira da 29 August 2008 (has links)
Made available in DSpace on 2014-12-17T14:10:17Z (GMT). No. of bitstreams: 1 CimariaPROS.pdf: 1137578 bytes, checksum: 6105cd049ff9ace294e10673c0d93fea (MD5) Previous issue date: 2008-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (&#8804;15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil / A carcinicultura ? a ?rea da aquicultura mais rent?vel do Rio Grande do Norte (RN), que ? um dos maiores produtores do Brasil. Por?m, as infec??es que acometem os camar?es v?m causando importantes perdas econ?micas. A infec??o ? resultado da intera??o entre o camar?o, o meio ambiente e o pat?geno. A altera??o desses fatores, pode levar a uma situa??o de estresse e suscetibilidade ? infec??es oportunistas. Uma dessas infec??es, causada pelo v?rus da Infec??o Hipodermal e Necrose Hematopoi?tica (IHHNV), encontra-se largamente distribu?da em v?rios pa?ses e apresenta uma grande variedade de hospedeiros. Para otimizar as condi??es de produ??o do camar?o de cultivo Litopenaeus vannamei, a esp?cie mais cultivada no Brasil, ? necess?rio compreender os efeitos dos fatores ambientais na suscetibilidade dessa esp?cie ?s infec??es. O presente estudo teve por objetivo determinar a preval?ncia do IHHNV e investigar a influ?ncia de fatores ambientais como a salinidade, temperatura, densidade de estocagem, oxig?nio dissolvido e pluviosidade na incid?ncia do IHHNV em fazendas de cultivo do L. vannamei, no estado do RN. Para determinar a preval?ncia do IHHNV foram utilizados 1089 amostras de L. vannamei coletados de sete fazendas. Para a realiza??o do estudo sobre a influ?ncia de fatores ambientais 525 amostras do camar?o L. vannamei foram coletadas em oito fazendas localizadas em regi?es de ?guas oligohalinas (0-1 ), mesohalinas (21-30 ) e hipersalinas (38-57 ), utilizando sistema de densidade de estocagem extensivo (&#8804;15 camar?es/m2), semi-intensivo (18-27 camar?es/m2) e intensivo (>30 camar?es/m2). A infec??o pelo IHHNV foi determinada em ple?podos e hemolinfa utilizando a rea??o da polimerase em cadeia (PCR). Os fatores ambientais foram registrados durante a coleta dos animais nos viveiros das fazendas, utilizando um refrat?metro para medir a salinidade e um medidor multi-par?metro para medir a temperatura e o oxig?nio dissolvido da ?gua. A preval?ncia do IHHNV no RN foi 43% (468 camar?es infectados de 1089), variando nas diferentes fazendas. Nas sete fazendas estudadas, a preval?ncia do IHHNV variou de 18,6% a 54,8%. As taxas de infec??o nas fazendas de ?guas oligohalinas, mesohalinas e hipersalinas foram respectivamente 43,10% (125/290), 31,2% (15/48) e 24,6% (46/187) e foi significativamente maior em camar?es cultivados em ?guas oligohalinas (P<0,001). As taxas de infec??o nos viveiros de sistema extensivo, semi-intensivo e intensivo foram respectivamente, 28,7%, 28,28% e 47,84% e foi significativamente maior em alta densidade de estocagem (P<0,001). Neste trabalho foi encontrado uma alta preval?ncia do IHHNV e um efeito significativo da salinidade e da densidade de estocagem, mas n?o da temperatura, pluviosidade e concentra??o do oxig?nio dissolvido sobre a taxa de infec??o pelo IHHNV no camar?o L. vannamei cultivado no Nordeste brasileiro
3

Untersuchungen zur Variabilität der Ausbildung hyperdermaler Wasserspeichergewebe unter Berücksichtigung variegater Periklinalchimären

Faßmann, Natalie 09 June 2008 (has links)
Die Arbeit ist in drei Teile untergliedert: Die Struktur "Hypodermales Wasserspeichergewebe" wird unter anatomischen, ökomorphologischen und evolutionsbiologischen Gesichtspunkten betrachtet. Die Anwesenheit eines farblosen Hypoderms erschwert bei der Musteranalyse variegater Periklinalchimären die Bestimmung der Konstitution der L2. Variegate Periklinalchimären mit Hypodermbildung wurden auf die Möglichkeiten der Bestimmung der L2 hin untersucht. Es werden verschiedene Entstehungsformen von maskierenden Mustern und die noch nicht beschriebenen Ringzellen vorgestellt, die den Idiotyp der L2-bürtigen Schicht anzeigen können. Ringzellen sind die Zellen, die im Bereich der Schließzellen an den substomatären Interzellularraum grenzen. Sie bilden dabei einen Ring um die Schließzellen, der im Flächenschnitt zu erkennen ist. Hypodermale Wasserspeichergewebe sind hauptsächlich bei tropischen Arten verbreitet. Die xeromorphe Struktur kommt sowohl bei den epiphytischen Bromelien als auch bei den hygromorphen Schattenpflanzen des tropischen Regenwaldes vor. Die beiden Selektionsfaktoren Trockenheit und Lichtintensität werden als mögliche Einflussfaktoren auf die Hypodermbildung diskutiert. Beispiele dafür, dass der Faktor Licht auch einen modifikativen Einfluss auf die Differenzierung der Hypodermzellen zu haben scheint, werden vorgestellt. Die Struktur "Hypodermales Wasserspeichergewebe" ist sowohl bei Monokotylen als auch Dikotylen gleichermaßen verbreitet. Es wird daher vermutet, dass es sich um eine analoge Struktur handelt, die mehrmals voneinander unabhängig zu verschiedenen Zeiten bei verschiedenen Arten entstanden ist. Innerhalb einer Gruppe verwandter Arten konnte sie mithilfe der Homologiekriterien als homolog eingestuft werden. / This paper contains three different issues: The structure "hypodermal water storage tissue" is considered from the anatomical, the ecomorphological and evolutionary aspect. Because hypodermal layers are non-green, it is difficult to make a pattern analysis of variegated periclinal chimeras and to determine the constitution of L2. Variegated periclinal chimeras with hypodermal layers were examined to the possibilities of determining L2. Different origins of masking patterns and the non-yet described ring cells are presented. Both structures are able to show the L2-genotype. Ring cells are those cells bordering the intercellular space near the stomata. In a cut parallel to the surface the ring built by ring cells is seen. The hypodermal water storage tissue is mainly distributed among tropical species. The xeromorphic structure occurs both to the epiphytic bromeliads and to the hygromorphic shadow plants of the tropical rainforest. The environmental factors humidity and solar radiation are discussed as possible influences on the development of hypodermal layers. Examples for the apparent modifying influence of solar radiation on the development of hypodermal cells are presented. The structure "hypodermal water storage tissue" occurs both to monocots and dicots. That indicates that it is an analogues structure and that it evolved several times independent of each other in different species. Among a group of nearly related species it could be classified by the aid of the criteria of homology as a homologues structure.

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