Made available in DSpace on 2014-08-13T14:50:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Bitstream added on 2014-08-13T18:00:48Z : No. of bitstreams: 1 000753355_20151216.pdf: 1415600 bytes, checksum: 54b033a2fd58f46d8099989bc9d184a2 (MD5) Bitstreams deleted on 2015-12-18T13:57:54Z: 000753355_20151216.pdf,. Added 1 bitstream(s) on 2015-12-18T13:58:34Z : No. of bitstreams: 1 000753355.pdf: 2526582 bytes, checksum: bdcccbcc43d606f2f47250af771db012 (MD5) / A bupropiona é um antidepressivo amplamente utilizado no tratamento da cessação tabágica que atua inibindo a recaptura neuronal de dopamina (DA) e noradrenalina (NE) com pouco efeito na recaptação da serotonina. Estudos prévios demonstraram que o tratamento com sibutramina, um bloqueador da recaptura de NE que age aumentado disponibilidade desta monoamina na fenda sináptica, influenciou a qualidade espermática diminuindo a fertilidade de ratos machos submetidos ao tratamento com este fármaco. A bupropiona possui ação sobre algumas funções sexuais como a ejaculação e a excitação, no entanto, não são encontradas na literatura informações sobre a influência desta droga na qualidade espermática de humanos ou de modelos animais. Nesse contexto, o presente trabalho tem como objetivo investigar os efeitos da administração de bupropiona sobre o comportamento sexual, parâmetros espermáticos e fertilidade de ratos machos e sobre a reatividade farmacológica do ducto epididimário isolado. Para tanto, 27 ratos machos (90 dias) foram aleatoriamente alocados em três grupos experimentais que receberam 15 mg/kg de bupropiona (BPP15, n=9), 30 mg/kg de bupropion (BPP30, n=9) e água destilada (veiculo, VEH, n=9) via oral durante 30 dias consecutivos. Ao final do tratamento os animais foram eutanaziados e tiveram seus órgãos reprodutores (testículos, epidídimos, próstata, vesícula seminal cheia e vazia) pesados. Os níveis séricos de testosterona, hormônio luteinizante e hormônio folículo estimulante foram determinados por radioimunoensaio e os testículos e epidídimos direitos foram coletados e processados para contagem espermática, determinação da produção diária de espermatozoides e determinação do tempo de transito espermático pela cabeça/corpo e cauda epididimária. Além disso, os espermatozoides da cauda do epidídimo direito foram utilizados para análise da motilidade e morfologia espermática. Em uma ... / Bupropion is a dopamine and norepinephrine reuptake inhibitor with lower effect on the serotonine reuptake widely used as smoking cessation and antidepressant drug. Previously studies showed that the treatment with the norepinephrine uptake blocker sibutramine, that acts increasing the level of this monoamine at the synaptic cleft impaired the sperm quality and fertility of the animals treated with this drug. Bupropion influences some sexual functions as ejaculation and arousal however, to our knowledge, there is no study investigating the effects of bupropion on human or animals model sperm quality. In this context, the present study investigated the effects of bupropion on sexual behavior, sperm parameters and fertility of male rats as well as its influence on epididymal duct contraction in vitro. For this, 27 male rats (90 days) were randomly allocated into three experimental groups that received 15 mg/kg of bupropion (BPP15, n=9), 30 mg/kg of bupropion (BPP30) and distillate water (vehicle, VEH, n=9) orally during 30 days. At the end of the treatment the animals were killed and his reproductive organs (testis, epididymis, prostate, full and empty seminal vesicle) were weighted. The levels of testosterone, luteinizing hormone and follicle stimulating hormone serum were determinate by radioimmunoassay and the right testis and epididymis were collected and processed to sperm count, daily sperm production and determination of sperm transit time trough epididymis. Furthermore, spermatozoa collected by the right epididymal cauda were used to analysis of sperm motility and morphology. In a second stage of this study 30 animals (n=10/experimental group), allocated and treated as describe previously, were used to analysis of male sexual behavior and fertility after natural matting. At the least stage of the study 18 animals (n=6/experimental group) were used to evaluating the effects of the treatment with ...

The pedunculated cirripede Pollicipes pollicipes (Gmelin) is of considerable economic importance in Portugal, particularly along the southwest coast. The current knowledge of its biology is poor, as evidenced by the paucity of available literature. Over a period of two years, P. pollicipes populations at Castelejo and Zavial were sampled from different tidal levels at approximately monthly intervals. Populations at two other sites, Ponta- da- Fisga and Sagres, were also sampled but at irregular intervals. The current study has provided definitive information on the annual reproductive cycle of P. pollicipes that is essential for any attempt at fisheries management. It is shown conclusively that shell-banding techniques are easily applicable to age and growth studies on these lepadomorph barnacles and has provided initial information on the growth rates and factors influencing shell deposition in experimental situations. An exhaustive data set provides a complete set of morphometric tools for the conversion of length measurements into dry and ash-free weights and demonstrates little differences between shapes of P. pollicipes on the different shores sampled. The demonstration that P. pollicipes is an obligate cross-fertilising barnacle has subtle implications in managing the fishery since it is imperative that any adopted policy incorporates aggregates of the barnacle as a unit necessary to ensure continuing recruitment. P. pollicipes when grown under simulated semi-diurnal conditions of emersion and immersion lay down clearly defined bands with almost an exact coincidence with the number of emersions. However, barnacles from the field showed no clear banding periodicity since band widths were very similar throughout the shell length with no regular "check" marks that could provide age estimation. Differences in the reproductive patterns between Castelejo and Zavial were minor and none statistically significant hence differences in environmental conditions between the two sites do not appeared to materially affect the species reproductive patterns. Adult barnacles carried fertilised eggs from April throughout September, and the percentage of individuals with egg masses correlated positively with air but not seawater temperature. Brooding success was greater with average air temperature in excess of 14 °C during months of strong upwelling and presumed food availability. Functional ovaries and testes are available in the population all year round but fertilisation does not appear to occur during the winter months. Reproduction of P. pollicipes on the southwest coast of the Algarve appears closely linked to the upwelling phenomenon with the rate of deposition of gonadal tissue probably determined by environmental temperature. Laboratory and field observations permitted to conclude that P. pollicipes is an obligate cross-fertiliser. Isolated and communal individuals were observed to carry ripe ovaries and seminal vesicles filled with sperm at the same time but fertilisation took place only on communal individuals. Increasing numbers of isolated individuals are found on the southwest coast of Portugal, probably as the result of an intense fishery. The assessment of the fishery impact on the natural population and the development of management policies for the fishery are imperative future measures in order to maintain the recruitment levels. Enforcement of reserve areas may prove a practical solution for Pollicipes management. Protected populations could serve as stocks for recruitment to other areas. A series of protected areas around the coastline would need to be established in areas that could easily be monitored and, if needed, physically protected. It might also be feasible to rotate areas every 3-4 years resulting in a better quality and increased quantity of P. pollicipes entering the fishery.

No description available.

Using data from the Third National Health and Nutrition Examination Survey, we assessed measures of puberty in U.S. girls in relation to blood lead levels to determine whether sexual maturation may be affected by current environmental lead exposure. The study sample included 1,706 girls 8-16 years old with pubic hair and breast development information; 1,235 girls 10-16 years old supplied information on menarche. Blood lead concentrations (range = 0.7-21.7 pg/dL) were categorized into three levels: 0.7-2.0, 2.1-4.9, and 5.0-21.7 μg/dL. Sexual maturation markers included self-reported attainment of menarche and physician determined Tanner stage 2 pubic hair and breast development. Girls who had not reached menarche or stage 2 pubic hair had higher blood lead levels than did girls who had. For example, among girls in the three levels of blood lead described above, the unweighted percentages of 10-year-olds who had attained Tanner stage 2 pubic hair were 60.0, 51.2, and 44.4%, respectively, and for girls 12 years old who reported reaching menarche, the values were 68.0, 44.3, and 38.5%, respectively. The negative relation of blood lead levels with attainment of menarche or stage 2 pubic hair remained significant in logistic regression even after adjustment for race/ethnicity, age, family size, residence in metropolitan area, poverty income ratio, and body mass index. In conclusion, higher blood lead levels were significantly associated with delayed attainment of menarche and pubic hair among U.S. girls, but not with breast development.

Flax (Linum usitatissimum L.) is being considered as a platform crop for the development of bioproducts. Potential benefits of bioindustrial farming include the provison of bioenergy and biomaterials, and opportunities for biorefining. Prior to the commercialization of crops intended for bioproducts however, the safety of the food/feed system and the environment must be assured. As part of a preliminary biosafety assessment I conducted a literature review and experiments to quantify seed-mediated gene flow from flax to the environment and food/feed system. Flax seed losses at harvest, seed persistence in soil, efficacy of herbicides to control volunteer survival and fecundity in subsequent crops, volunteerism (density and occurrence) and volunteer emergence periodicity in follow crops in commercial fields were examined. Total seed losses at harvest in commercial fields were variable (2.7 to 44.2 kg ha-1). Flax has a short longevity in the seed bank (2 to 3 years). Flax has been selected for reduced seed dormancy and volunteer flax seed persistence may be hastened by burial. Compared to other domesticated crops, flax has a prolonged period of emergence and calculated EM50 values (the growing degree days required for 50% emergence) ranged from 227 to 340 growing degree days (GDD). Flax volunteers reached their period of peak emergence earlier in conventional tillage than in reduced tillage fields. Volunteer flax densities were highest prior to herbicide applications (10.4 to 570.2 plants m-2) in all fields the year following flax production (2005) and diminished over time. Volunteers that emerge in the spring may be controlled with registered herbicides. Glyphosate and fluroxypyr tank-mixed with either monohydrate sodium salt of 2,4-dicholorophenoxy acetic acid (2,4-D) or monochlorophenoxyacetic acid Ester 500 (MCPA) were most effective in reducing volunteer flax density, biomass, and fecundity. These herbicides also reduced the adventitious presence of volunteer flax seed in spring wheat (from over 8.5% to 0.16%). Best management practices could be adopted to mitigate seed-mediated gene flow from flax in agricultural productions systems, but thresholds of zero are not biologically realistic. The agronomic baseline data generated in this thesis however, suggests that flax may be an appropriate crop platform for bioindustrial products. / Plant Science

No description available.

<p>Bryophytes, by their haploid dominant life cycle, possess several unique qualities ideal for study of mating patterns. In particular, the possibility of intragametophytic selfing in some species, and the vegetative propagation of gametes allow for a unique window into the haploid stage that is intractable in other groups. Despite these advantages, there have been relatively few studies on mating patterns bryophytes in natural populations. <italic>Sphagnum</italic> (peatmoss) is an excellent case study in the interactions between sexual condition, ecology, and mating patterns. In the first Chapter, we use microsatellites to characterize the genetic diversity and mating patterns in fourteen species of <italic>Sphagnum</italic>, diverse in sexual condition (separate vs combined sexes in the haploid stage) and ecology (microhabitat variance along the water table). We find that genetic diversity and mating patterns are related only in species with separate sexes, that sexual condition and ecology have interacting effects on inbreeding coefficients, and that inbreeding depression is not a common phenomenon in <italic>Sphagnum</italic>. In the second Chapter, we conduct an intensive survey of one population of <italic>Sphagnum</italic> macrophyllum, to detect whether variance in haploid fecundity and mating success is related to diploid fitness. We find a relationship between mating success and fecundity (a signal of sexual selection), and fitness of the diploid generation is connected to the parentage of the haploid generation. Finally, in Chapter 3 we use phylogenetic comparative methods to track the phylogenetic signal in microhabitat preference in <italic>Sphagnum</italic>. We find extremely fast rates of evolution along the micronutrient gradient, but high phylogenetic signal along a hydrological gradient. Given that <italic>Sphagnum</italic> species living high above the water table have reduced water availability, phylogenetic signal in the hydrological gradient has macroevolutionary implications for mating systems in <italic>Sphagnum</italic>.</p> / Dissertation

No description available.

Increasing introductions of non-native terrestrial slugs (Mollusca: Gastropoda) are a concern to North American regulatory agencies as these generalists impact the yield and reduce the aesthetic value of crop plants. Understanding how the increase in diversification in North American cropping systems affects non-native gastropods and finding effective biological control options are imperative for pest management; however, little research has been done in this area. This study tested the hypothesis that dietary diversification affects the biological control capacity of a generalist predator and allows the slug pest Deroceras reticulatum (Müller) (Stylommatophora: Agriolimacidae) to more effectively fulfill its nutritional requirements. Results showed no significant correlations between dietary diversification and slug development; however, this was likely due to the addition of romaine lettuce to all treatments. The study also showed that dietary diversification had no significant effect on D. reticulatum egg production, with self-fertilizing slugs consistently having significantly higher egg production than outcrossing slugs. Most significantly, this research demonstrated reductions in plant damage by D. reticulatum in treatments containing the North American carabid beetle Scarites quadriceps Chaudoir (Coleoptera: Carabidae) with the presence of alternative prey having no effect, supporting its use in biological control efforts in spite of its generalist feeding habits.

Pharmaceuticals in the aquatic environment is an emerging issue and the risks they pose are mostly unknown. They are used in large amounts throughout the world and can enter the environment, as the active metabolite or unmetabolised, through excretion by people and improper disposal. As these drugs are designed to have specific biological effects in a specific organism (as well as sometimes having other non-specific side effects), their potential to cause effects within the environment is great. Clofibric acid (the major metabolite of the lipid lowering drug, Clofibrate) is non-biodegradable, highly motile, very persistent and frequently detected at μg/I levels in the environment. I studied possible effects of clofibric acid in fish, using different experimental approaches and endpoints. The studies involve two different species, and for one of these species, fish at different stages of development. The chapters within this thesis have presented the first evidence (albeit preliminary) of clofibric acid having effects on both adult and embryo fish. When fathead minnow embryos were exposed to clofibric acid, the effects seen included changes in the eggshell, time to hatch, hatchability, mortality and viability. Adult fathead minnow were similarly exposed and significant effects on specific parameters were also observed. These included effects on lipid metabolism, steroidogenesis and spermatogenesis - thought to be via cholesterol transport - as well as significant effects on the expression of several genes involved in lipid metabolism and detoxification. Exposure of juvenile (sexually undifferentiated) bream also found significant differences in some endpoints. Other results suggested, less pronounced effects of clofibric acid on some other parameters. The results from this research show that there are effects of clofibric acid in pathways which were not only unexpected in fish (for example, steroidogenesis, spermatogenesis and gene expression), but also at concentrations below those previously shown to have any biological effects on fish. These effects indicate that clofibric acid may potentially have an impact on fish fecundity, and even more worryingly, on human health for those people prescribed it.