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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.
71

Aspectos morfofisiológicos na clonagem de Eucalyptus benthamii / Morphophysiological aspects in the cloning of Eucalyptus benthamii

Gilvano Ebling Brondani 18 May 2012 (has links)
Dentre as poucas espécies de Eucalyptus que apresentam aptidão ao cultivo em regiões de baixas temperaturas e a geadas frequentes, destacam-se genótipos de Eucalyptus benthamii que representam opções para futuros plantios florestais em diferentes regiões brasileiras. Porém, existem poucas informações quanto a obtenção de mudas clonais, e se focarmos as espécies aconselhadas para o plantio em condições subtropicais, tal carência é ainda maior, principalmente ao considerar os fatores endógenos e exógenos para o enraizamento adventício. Baseado no exposto, o presente trabalho teve como objetivo geral avaliar aspectos morfofisiológicos da clonagem de genótipos de Eucalyptus benthamii por meio das técnicas de miniestaquia e micropropagação. Para tanto, o trabalho foi dividido em quatro estudos básicos. O primeiro estudo (Capítulo 2) baseou-se na avaliação da morfofisiologia de um minijardim clonal em relação a diferentes concentrações de Zn e B ao longo de sucessivas coletas de brotações. O segundo estudo (Capítulo 3) foi baseado em avaliar o enraizamento de miniestacas quanto a diferentes concentrações de Zn e B e aplicação de AIB ao longo de sucessivas coletas de brotações. O terceiro estudo (Capítulo 4) baseou-se em avaliar a dinâmica de enraizamento de miniestacas quanto a diferentes concentrações de AIB, tempo ótimo de permanência de miniestacas enraizadas em casa de vegetação e a origem da conexão vascular da raiz emitida. Por fim, o quarto estudo (Capítulo 5) foi baseado no desenvolvimento e estabelecimento de protocolo para a micropropagação visando a produção de microcepas para formar um microjardim clonal. Em termos gerais, a sobrevivência das minicepas, produção de miniestacas por metro quadrado ao ano e os teores foliares de macro e micronutrientes variaram significativamente em relação as concentrações de Zn e B, apresentando diferentes respostas ao longo das coletas de brotações no minijardim clonal. Os teores foliares de carboidratos solúveis não estruturais variaram significativamente de acordo com as coletas de brotações e solução nutritiva, sendo que o aumento das concentrações de Zn e B na solução nutritiva induziu a redução dos teores de carboidratos solúveis não estruturais. A porcentagem de enraizamento dos materiais clonais foi baixa, sendo considerados de difícil propagação pela miniestaquia. A presença de Zn e B na solução nutritiva (concentrações variando de 1,0 a 2,0 mg L-1) associadas a presença de AIB induziram os maiores índices de enraizamento. A aplicação de AIB na concentração de 2.000 mg L-1 favoreceu a indução de raízes, e o intervalo de 35 a 42 dias foi o mais indicado para a permanência das miniestacas enraizadas em casa de vegetação. De acordo com as análises histológicas da rizogênese foi verificado que a raiz adventícia apresentou conexão direta com o câmbio vascular. A multiplicação in vitro de gemas axilares dependeu do clone, meio de cultura e concentração de regulador de crescimento e, o alongamento de brotações dependeu do clone e regulador de crescimento. O protocolo de micropropagação foi eficiente para a produção de microplantas de Eucalyptus benthamii as quais podem ser usadas para a formação de um microjardim clonal. / Few Eucalyptus species present adaptation for cultivation in regions subject to low temperatures and frequent frosts, and Eucalyptus benthamii genotypes may represent options for future forest plantations in different regions of Brazil, in view of its excellent silvicultural performance in these conditions. However, there is little information on obtaining clones, and considering the species recommended for planting in subtropical conditions, this lack of information is even greater, mainly when considering the endogenous and exogenous factors for the adventitious rooting. Based on these information, the present work was aimed the conducting of studies on morphophysiological aspects during the cloning of Eucalyptus benthamii through of the mini-cuttings and micropropagation techniques. Therefore, the work was divided into four basic studies. The first study (Chapter 2) was based in evaluate the morphophysiology of a clonal mini-garden regarding to Zn and B concentrations during successive shoot collections. The second study (Chapter 3) was based in evaluate the induction of adventitious rooting in mini-cuttings regarding to genotype, Zn and B concentrations, shoot collections and IBA application. The third study (Chapter 4) was based in evaluate the adventitious rooting percentage of selected genotypes regarding the IBA concentration, optimal time of permanence of rooted mini-cuttings in a greenhouse and the origin of the vascular connection. Finally, the fourth study (Chapter 5) was based in develop a method for cloning of selected genotypes through micropropagation technique for the formation of a clonal micro-garden. In overall terms, mini-stumps survival, mini-cuttings production per square meter per year and foliar content of macro and micronutrients varied significantly in relation to treatments, presenting different responses according to shoots collection of the clonal mini-garden. The content of soluble carbohydrates non-structural of leaves varied regarding the shoots collection and nutrient solution. The increasing of the Zn and B concentrations in the nutrient solution induced reduction of the total content of soluble carbohydrates non-structural of leaves. The adventitious rooting percentage was low, and the genotypes were considered difficult to propagation by mini-cuttings technique. The ministumps fertigated with nutrient solutions containing Zn and B (concentrations of 1.0 at 2.0 mg L-1) associated with the IBA application presented the greater adventitious rooting percentage. The IBA application in the concentration of 2,000 mg L-1 resulted in the greater speed of rooting and rooting percentage, and the interval of 35 to 42 days was the most suitable for the permanence of mini-cuttings rooted in a greenhouse. According to the histological analysis of rhizogenesis was verified that the adventitious root presented direct connection to the vascular cambium. The in vitro multiplication of axillary buds depends of the genetic material, culture medium and concentration of plant growth regulator and, the shoots elongation depends of the genetic material and plant growth regulator. The micropropagation protocol was efficient for the microplants production of Eucalyptus benthamii and can be used to form a clonal microgarden.
72

Sexual Identity and Social Anxiety in Emerging Adulthood

Akibar, Alvin 05 1900 (has links)
Elevated social anxiety (SA) is linked to issues with emotional distress, substance use, and social anxiety disorder (SAD). Notwithstanding concerns of how sexuality has been defined in the extant literature, emerging evidence suggests that the prevalence of SA and related challenges may be disproportionately present among sexual minorities, including lesbians, gay men, and bisexuals (LGBs). This trend may be especially relevant within the developmental context of emerging adulthood, an important period for development of sexual identity, and a time when individuals are already predisposed to heightened feelings of SA. The present study examined the relationship between sexual orientation (measured using sexual identity, sexual attraction, and past romantic and sexual behavior) and social anxiety (related to social interaction and social performance) among emerging adults. minority sexual identities [Welch's F(5,48.08) = 5.56, p = .002, ηp2 = .02.], same-sex attraction [Welch's F(4,108.06) = 11.27, p < .001, ηp2 = .04], and same-sex romantic [Welch's F(5,85.91) = 6.88, p < .001, ηp2 = .03] and sexual experiences[F(5,61.95) = 8.88, p < .001, ηp2 = .04], particularly among those who indicated attraction to multiple sexes. Findings support research that indicates that sexual minority adults experience higher levels of SA than majority (i.e., heterosexual, opposite-sex oriented) adults, and that assessment of sexuality may reflect number of sexual minorities identified. Future directions including intersections of race/ethnicity and gender are discussed.
73

The Metabolic Physiology of Planarian Flatworms

Lewallen, Melissa A 08 1900 (has links)
Using a high throughput closed respirometry method to measure oxygen consumption, I determined metabolic rates in asexual and sexual Schmidtea mediterranea and Girardia dorotocephala, as a function of temperature, taxon, stressors, reproductive mode, age, regeneration, and specific dynamic action. This study has shown that oxygen consumption can reliably be measured in planaria using optode closed respirometry, and also provided a reliable method for measuring wet mass in planaria, which has been a challenge to researchers in the past. This research revealed that oxygen consumption in S. mediterranea is 1.5-2.1X greater in the sexual strain over the asexual strain at 13-18°C. Within the sexual strain, oxygen consumption is 1.5 -2.2X greater in sexually mature adults over the sexually immature groups (hatchlings, juveniles, and regenerating sexuals). Furthermore, I was able to quantify differences in sexual morphology between these groups exhibiting significant differences in oxygen consumption. The results of this research supports a theory of higher metabolic costs with sexual maturity in S. mediterranea. Therefore, this study has established sexual and asexual S. mediterranea as simple, yet attractive models for investigating energetic costs between sexual and asexual phenotypes. This research also provided quantitative values for specific dynamic action in planaria, with a maximum increase in oxygen consumption of 160% induced by feeding, as well as metabolic relationships in planaria involving temperature, age, and regeneration. These values establish planaria as one of the simplest animal models in which common metabolic patterns, such as SDA and poikilothermic temperature sensitivity, have been demonstrated. Therefore, this research has contributed to the overall knowledge of the basic physiology in this animal, providing the framework for future metabolic studies in planaria involving environmental factors, reproduction, regeneration, development, and aging. Information from this study may supplement interpretation and understanding of modern cellular, molecular, and genomic studies in planaria.
74

Obligatorisk Sexualitet och Asexuell Existens : Patologiserad olust, (a)sexuella (icke)subjekt och frånvaro av begär som (o)möjliggjord position.

Lindgren, Matilda January 2007 (has links)
<p>Mot bakgrund av att asexualitet på senare år formulerats som en möjlig sexuell identitet, orientering eller preferens är syftet med uppsatsen att teoretisera den asexuella positionen – här definierat som ”frånvaro av lust till sexuell praktik”. Detta görs genom en nära läsning av fyra texter som varit centrala inom feministisk och queer teoribildning, med intentionen att undersöka hur asexualitet positioneras i relation till dessa teorier. De teoretiska utgångspunkterna hämtas från feministiska och konstruktivistiska teorier om kön, sexualitet, makt och subjektstatus, främst Michel Foucault (1976)och Judith Butler (1990). Mina läsningar visar att i Gayle Rubins sexuella värdehierarki (1984) tilldelas positioner utifrån sexuellt aktörskap, och det är således sexuella subjekt som kan emanciperas. I Adrienne Rich’s text om obligatorisk heterosexualitet (1980) tillskrivs även den icke-sexuella kvinnan aktörskapet att undkomma tvångsheterosexualisering - Rich’s införande av ett lesbiskt kontinuum kan ses som en dekonstruktion av en sexuell kategori. I min läsning av Michael Warner (1993) frågar jag huruvida den queera metoden även kan användas till att ifrågasätta normer om att vara sexuell, och i min läsning av Butler (1990) diskuterar jag frånvaro av begär i relation till möjliga subjektspositioner inom ramen för en heterosexuell matris. I min slutdiskussion återknyter jag till Foucault, och problematiserar (a)sexualitet ur ett könsmaktsperspektiv. Jag avslutar med att problematisera den gränsdragning mellan sexuellt och icke-sexuellt vi alla ständigt avkrävs att göra.</p>
75

Obligatorisk Sexualitet och Asexuell Existens : Patologiserad olust, (a)sexuella (icke)subjekt och frånvaro av begär som (o)möjliggjord position.

Lindgren, Matilda January 2007 (has links)
Mot bakgrund av att asexualitet på senare år formulerats som en möjlig sexuell identitet, orientering eller preferens är syftet med uppsatsen att teoretisera den asexuella positionen – här definierat som ”frånvaro av lust till sexuell praktik”. Detta görs genom en nära läsning av fyra texter som varit centrala inom feministisk och queer teoribildning, med intentionen att undersöka hur asexualitet positioneras i relation till dessa teorier. De teoretiska utgångspunkterna hämtas från feministiska och konstruktivistiska teorier om kön, sexualitet, makt och subjektstatus, främst Michel Foucault (1976)och Judith Butler (1990). Mina läsningar visar att i Gayle Rubins sexuella värdehierarki (1984) tilldelas positioner utifrån sexuellt aktörskap, och det är således sexuella subjekt som kan emanciperas. I Adrienne Rich’s text om obligatorisk heterosexualitet (1980) tillskrivs även den icke-sexuella kvinnan aktörskapet att undkomma tvångsheterosexualisering - Rich’s införande av ett lesbiskt kontinuum kan ses som en dekonstruktion av en sexuell kategori. I min läsning av Michael Warner (1993) frågar jag huruvida den queera metoden även kan användas till att ifrågasätta normer om att vara sexuell, och i min läsning av Butler (1990) diskuterar jag frånvaro av begär i relation till möjliga subjektspositioner inom ramen för en heterosexuell matris. I min slutdiskussion återknyter jag till Foucault, och problematiserar (a)sexualitet ur ett könsmaktsperspektiv. Jag avslutar med att problematisera den gränsdragning mellan sexuellt och icke-sexuellt vi alla ständigt avkrävs att göra.
76

Genetische Untersuchungen zu den Voraussetzungen und Konsequenzen einer rezedenten Lebensweise am Beispiel der Vogelkirsche (<i>Prunus avium L.</i>) / Genetic analysis of the prerequisites and consequences of a recedent life form. A case study on wild cherry (<i>Prunus avium L.</i>)

Höltken, Aki Michael 27 June 2005 (has links)
No description available.
77

Strategies of Sexual Reproduction in Aphids / Fortpflanzungsstrategien der Sexuellen Generation von Blattläusen

Dagg, Joachim 30 October 2002 (has links)
No description available.

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