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Inhibiting peripheral serotonin (5-HT) synthesis has been shown to prevent the development of diet-induced obesity, glucose intolerance, insulin resistance and hepatic lipid deposition and to increase brown adipose tissue (BAT) thermogenic capacity. This thesis investigated 1) what effects 5-HT has on brown adipocytes (BAs), 2) if 5-HT and/or selective serotonin reuptake inhibitors (SSRIs) impair BAT function, 3) if 5-HT directly inhibits BA via a receptor-mediated mechanism, 4) which 5-HT receptor is predominantly expressed in BAT, 5) if 5-HT receptor antagonism improves BAT function and 6) if 5-HT receptor inhibition reduces SSRI induced weight gain. In murine BAs, 5-HT at concentrations ≥100 μM acutely reduced lipolysis, lipid accumulation and glycolytic flux but did not impair oxygen consumption; whereas 10 nM 5-HT reduced Ucp1 promoter activity via an extracellular receptor-mediated mechanism. Acute injection of 5-HT or the selective serotonin reuptake inhibitor (SSRI) Paroxetine decreased BA T thermogenic capacity and energy expenditure (EE), respectively. Mice lacking the serotonin transporter gene (Slc6a4-/- mice) had increased adiposity, decreased locomotor activity and increased food intake. However, male Slc6a4-/- mice had increased BAT thermogenic capacity, in contrast to the reduced EE expenditure following acute administration of Paroxetine. Using, RNA-Seq analysis and measurements of canonical 5-HT receptor second messengers (i.e. Ca2+ and cAMP transients), 5-HT2A was identified as the highest expressed 5-HT receptor in murine and human BAs and the only detected active 5-HT receptor in murine BAs. Genetic elimination of 5-HT2A prevented 5-HT induced increases in Ca2+ transient peaks and decreases in Ppargc1a mRNA expression in cultured BAs. In vivo ablation of 5-HT2A in adipose tissue increased BAT thermogenic capacity. Furthermore, in silico analyses predicted that pharmacological inhibition of 5- HT2A would induce a thermogenic program. In vitro, 5-HT2A receptor antagonists eliminated 5-HT induced Ca2+ transients and in vivo, a single injection of a peripherally-restricted 5-HT2A antagonist (Xylamidine) prevented 5-HT-induced impairments in BAT-mediated EE. Chronic administration of Xylamidine to chow- fed mice for 5-weeks improved BA T thermogenesis. Co-administration of Xylamidine with Paroxetine, however, did not attenuate Paroxetine-induced weight gain but did improve BAT functional capacity Therefore, 5-HT2A antagonism improves BAT thermogenic capacity but does not increase EE. This represents a novel therapeutic approach for increasing thermogenic capacity that may be used in conjunction with BAT activating strategies to increase EE and attenuate obesity. / Thesis / Doctor of Philosophy (PhD) / Obesity is a growing global pandemic caused by excessive energy intake over energy expenditure (EE). Some medications, such as certain selective serotonin (5-HT) reuptake inhibitor (SSRI) type antidepressants, also contribute to weight gain via reasons which are not fully understood. Currently available weight- loss medications decrease energy intake but do not affect EE. Recently, inhibiting the production of 5-HT outside the brain decreased weight gain in a model of obesity. Furthermore, this was associated with an improvement in the activity of a specialized type of adipose tissue, called brown adipose tissue (BAT). BAT is capable of expending energy in the form of thermogenesis and thus when active increases energy expenditure. We hypothesized that 5-HT impairs BAT activity and that blocking 5-HT activity may reduce weight gain in a model of antidepressant- induced weight gain. Herein, we investigated whether elevating 5-HT or increasing 5-HT downstream signaling modified BAT activity, which 5-HT receptor(s) is/are predominantly expressed in brown adipocytes (BAs), and what the effect on BAT would be if this/these receptors were eliminated. We found that in cell culture “supraphysiological” doses of 5-HT acutely impaired BA lipid mobilization and glucose metabolism; whereas, circulating concentrations of 5-HT impaired expression of select mitochondrial genes when serotonin transport was reduced. In mice, acute injections of high dose 5-HT attenuated BAT activity in response to an adrenergic stimulus. Acute treatment with an SSRI decreased EE and locomotor activity. Mice genetically lacking the serotonin transporter (the target of SSRIs) had increased weight gain (particularly fat mass), increased food intake and reduced locomotor activity, but improved BAT functional capacity. We subsequently identified that the predominantly expressed and active receptor in BAs was the 5- HT2A receptor. Genetically eliminating the 5-HT2A receptor in BAs prevented 5- HT’s reduction of a major mitochondrial gene expression regulator and improved BAT functional capacity in mice. Inhibiting 5-HT2A with a 5-HT2A brain impermeable antagonist, Xylamidine, increased BAT functional capacity in mice. Treating mice with Paroxetine (Paxil®), a SSRI known to increase weight gain, and Xylamidine did not attenuate Paroxetine-induced weight gain nor increase EE but did improve BAT functional capacity. In conclusion, we found that 1) chronic treatment with physiological levels of 5-HT impaired BAT functional capacity, 2) elimination/inhibition of adipocyte 5-HT2A improved BAT functional capacity in vivo and 3) inhibiting peripheral 5-HT2A alone did not attenuate Paroxetine- induced weight gain.

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Successful conservation of brown bears (Ursus arctos) in Europe is associated with public acceptance of damages caused by bears. Recent increases in sheep depredation and beehive damage in central Austria resulted in the deaths of two bears there. Since bear numbers are low in most European populations, alternatives to the elimination of problem bears associated with damage incidents must be sought. The events described above led to the formation of the Bear Management Group responsible for designing a management plan for Austria that will outline procedures for dealing with bear damage and conservation strategies. This study provides an overview of the magnitude and seasonal patterns of brown bear damage in Romania, Italy, Slovenia, Norway, Sweden, and Austria. It also illustrates how bears are managed in European countries by comparing different management strategies for dealing with brown bear damage, describing how bear management is organized, determining which organizations are involved, and explaining which duties these fulfill. Bear damage data were obtained from interviews with wildlife managers, hunters, and farmers in Romania, Italy, Slovenia, Norway, Sweden, and Austria, and from official records of their bear management agencies. Most damage incidents involved sheep and beehives in all countries. All countries offered a more or less well functioning damage compensation program to farmers. Conservation success, especially for small bear populations, seemed to be related to a good compensation program and reducing damage to livestock and property. Possible improvements of management strategies to reduce damage and increase conservation success in theses countries were discussed The second part of this study was the assessment of the organizational structure of different bear management programs in Europe. Brown bear management in Europe included a broad spectrum of goals, ranging from no protection, to regulated hunting, to total protection. In each country, different organizations were involved in bear management, including private and governmental organizations. For each study country, I outlined which organizations were involved in bear management, determined if a management plan existed,described if and how hunting and damage compensation were structured, explained how each country dealt with problem bears, and finally, detailed what kind of management problems each country encountered. I tried to find management patterns for bear management in Europe, including advantages and disadvantages of each approach and their effectiveness within the countries they were applied. Methods included a content analysis of interviews with wildlife managers, farmers, and local people in each country.Results showed that two general types of management approaches could be identified. Romania, Sweden and Southern Slovenia took a conservationist approach, which was characterized by economic use of their bear population. All of these countries had viable bear populations. Romania and Southern Slovenia included an additional characteristic of feeding bears, which could be viewed as a utilitarian management scheme. The second management approach, which was classified as the preservationist approach, was observed in Norway, Italy, Northern Slovenia, and Austria. This management strategy was characterized by year-long protection of bears, low population numbers, and no feeding of bears. Further results of management differences in problem bear management, damage compensation, public education, and effectiveness of management approaches were summarized. The study provides a reference on bear management strategies in Europe. / Master of Science

Herbicide resistance, regulations on pesticide use, and cost of pesticides are all challenges for managing weeds in production agriculture. The use of cover crops (CC) has emerged as a promising integrated weed management tool to aid in weed suppression. There are many questions concerning the best management practices to reap the most benefits from CC. Research was conducted to determine if the application of a pre-plant herbicide as well as the type of CC planted would increase CC biomass and subsequent winter weed suppression. Early planting and selecting a cereal rye or a cereal rye-containing mixture are the most important factors to obtain the greatest CC biomass production. Additionally, the combination of a CC and a pre-plant herbicide increased weed suppression compared to a no CC (winter fallow) treatment or CC without a pre-plant herbicide. The difference in Palmer amaranth emergence between a rolled cereal rye CC or one that is left standing was also examined along with termination timing to achieve different CC biomass levels. Overall, greater CC biomass suppressed more Palmer amaranth, but treatments of rolled or standing or termination timing did not affect weed suppression consistently. Light penetration data also showed that greater CC biomass led to a decrease in light penetration through the CC canopy, which could be a factor in reducing Palmer amaranth emergence particularly at the greater CC biomass accumulation levels. Additionally, studies were conducted to investigate the effect of cereal rye CC termination timing (i.e., "planting green" being CC terminated at the time of soybean planting or "planting brown" being CC terminated 2 weeks prior to planting) on Palmer amaranth suppression, as well as to determine how termination timing influences herbicide program optimization. A delay in emergence and growth rate of Palmer amaranth was documented in the CC containing plots when compared to the no CC plots, but no differences were observed between the termination timings. Additionally, significantly lower Palmer amaranth densities were observed under CC containing plots when compared to the no CC treatments. Within CC treatment options, the most economical option was planting green with a single postemergence herbicide application, but overall, no CC treatments were more economical programs. Finally, research was conducted to understand weed and corn competition for nitrogen when hairy vetch + cereal rye CC was present. A range of side dress nitrogen fertilizer rates, weedy versus weed free herbicide programs, and CC versus no-CC treatments were compared. Overall, yield did not differ among treatments. Ear leaf and grain nitrogen was generally greater under weed free, CC, and when fertilized at or above yield goals respective of location. Despite these findings, early season weed control in corn is still necessary to achieve maximum potential yield. These studies indicate that CC biomass is consistently the most important factor for achieving weed suppression, and that CC results can vary in response to environmental and management effects. More research is therefore necessary to evaluate the effects of CC over greater periods of time. / Doctor of Philosophy / Herbicide resistant weeds are a major challenge for farmers across the globe. With the increased number of weed species resistant to multiple herbicides and the restrictions on pesticide use, farmers need more tools to control weeds. The use of cover crops (CC) to suppress weeds can be a viable integrated weed management tool for farmers. Although there are multiple benefits associated with CCs, there are also many drawbacks. CCs are an additional input cost for farmers, and require a greater level of management when compared to conventional systems. There are also many questions concerning best management practices in order to reap the benefits of CCs. Previous research indicates CC biomass is the most important factor in achieving weed suppression. Research trials were conducted at Virginia Tech to determine whether CC species as well as the application of preplant herbicide at the time of CC planting would affect CC biomass production as well as weed suppression. Cereal rye-containing plots produced more biomass overall compared to hairy vetch alone or crimson clover and earlier plantings accumulated greater CC biomass. Additionally, planting earlier was significant for CC biomass accumulation while applying a pre-plant herbicide was not. Weed suppression varied by species but was more successful when both a CC and pre-plant herbicide were applied as compared to no CC and no pre-plant herbicide application. Termination timing and mechanism of CC termination are both known to impact potential CC benefits. Many farmers roll their CC at termination, but it is unclear whether rolling is necessary for weed suppression benefits and soybean yield. Palmer amaranth counts were collected at four and six weeks after planting, as well as yield data across a range of cereal rye CC biomass levels, rolled or left standing at termination, and planted green (CC terminated at the time of planting) versus brown (CC terminated 2 weeks prior to planting). Light penetration measurements were also collected to observe changes in light availability through a CC canopy. Overall, CC treatments reduced Palmer amaranth emergence when compared to no CC, and suppression increased with greater CC biomass. Yield did not differ among treatments, therefore CC management can be tailored to weed suppression efforts. There were clear patterns of light penetration reduction as CC biomass increased. This reduction in light penetration could be part of the reason for the decreased Palmer amaranth emergence with greater CC biomass. Overall, the most important factor affecting weed suppression is accumulation of greater CC biomass. Research was conducted to determine differences in Palmer amaranth suppression due to CC termination timing, as growers have experimented with planting green while traditionally, planting brown or no CC at all was more common. Palmer amaranth groups were created and followed throughout a 10-week period to examine density and growth rates, which allowed various herbicide programs to be simulated and compared. A delay in emergence and growth rate of Palmer amaranth was documented in the CC containing plots when compared to the no CC plots, but no differences were observed between the termination timings. Additionally, significantly lower Palmer amaranth densities were observed under CC containing plots when compared to the no CC treatments. The most effective programs varied by year, but amongst CC options, planting green with a single POST herbicide was optimal, but overall, no CC treatments were more economical due to the expenses associated with CC seed and planting. If a grower is planning on using a CC, the recommendation is therefore to plant green, as lower costs were associated with this practice. In addition to weed suppression benefits, the potential for leguminous CC such as hairy vetch to provide nitrogen for the cash crop is another reason that farmers may plant CCs. However, the effect of a CC on weed competition for nitrogen is still unclear, as the nitrogen released by the CC can also stimulate weed emergence while the CC itself is physically suppressing weeds through its biomass. A study was established to evaluate the effects of CC or no CC, weedy or weed free herbicide programs, and six nitrogen side dress fertilizer rates on yield. Overall, greater concentrations of nitrogen in the ear leaf and in grain were found under CC, weed free, and when fertilized-to-yield goal for the respective locations. Yield was not responsive to treatment effects, and agronomic optimum analysis indicated that a side dress nitrogen to yield goal is still the best option even under CC to achieve optimal yields. Use of CCs is another tool for farmers to implement in their weed control programs. Proper management of CCs can result in increased weed suppression and provide other benefits not examined in this document. However, varying results by location calls for further research to explore the intricacies of CC management and its effect not only on other weed species, but also on other major cash crops.

A otimização do metabolismo e a maximização do desempenho das aves dependem de adequada nutrição. Dentre os nutrientes essenciais a essa nutrição estão o aminoácido lisina e zinco, objetos desta avaliação, sobre a produção, qualidade, composição dos ovos e morfologia intestinal. Setecentos e vinte poedeiras foram submetidas em dois períodos de avaliação. Cada período correspondeu a 12 semanas, sendo a Fase-I de 24 a 36 e a Fase-II de 48 a 60 semanas de idade. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, dispostos em esquema fatorial (5 x 3) aplicados em seis repetições e a unidade experimental foi composta de oito aves/parcela. Os níveis de lisina digestível foram: 0,482; 0,527; 0,582; 0,644 e 0,732% e de zinco: 137, 309 e 655 ppm na forma de quelato. Na Fase-I, houve interação de lisina digestível e zinco nas variáveis: consumo de ração médio diário, conversão alimentar, porcentagem de postura e na massa de ovo. Na Fase-II a interação foi evidenciada no consumo de ração médio diário, peso da casca, composição química e taxas de deposição protéica, lipídica e mineral do ovo. Na maior concentração dietética de zinco o acréscimo de lisina digestível coincidiu com aumento linear no peso da casca. Por outro lado, o acréscimo de zinco independentemente do nível de lisina na dieta, culminou com a redução do peso do ovo e da porcentagem da matéria mineral na gema limitando a eficiência de deposição mineral nessa fração do ovo. Resultado inverso ocorreu no albúmen, quando houve aumento na porcentagem de matéria mineral. Em ambas as fases, a menor concentração de zinco (173ppm) atendeu as necessidades de produção e qualidade das aves. O valor médio estimado de lisina digestível foi de 0,662% ± 0,03 para a Fase-I e de 0,609 ± 0,004 para a Fase-II. / The optimization of the metabolism and poultry performance maximization depend of adequate nutrition. Among the essential nutrients there are lysine and zinc, subjects this evaluation, on egg production, quality, composition and intestinal morphology. Seven hundred and twenty laying were submitted into two study periods. Each period corresponded to 12 weeks, being 24 to 36 Phase I and 48 to 60 weeks of age Phase II. The treatments were allotted to a completely randomly, disposed randomized design under factorial scheme (5 x 3) with six replications and eight bird per experimental unit. The lysine levels were: 0.482; 0.527; 0.582; 0.644 e 0.732% and zinc: 173, 309 and 655 ppm in chelate form. At Phase I, there was interaction of digestible lysine and zinc in variables: average feed intake, feed: gain, laying percentage and egg mass. At Phase II the interaction was evidenced at the average feed intake, shell weight, chemical composition, proteic, lipidic and mineral depositionn rates egg. In the higher dietetic zinc concentration the digestible lysine accretion coincide with linear increase in shell weight. On the other hand, the zinc increase, of independently from diet lysine level, coincide with egg weight and yolk mineral percentage decrease, however limiting the mineral accretion efficiency in this egg fraction. In both Phases, the smallest zinc concentration (173ppm) attended the poultry production and quality needs. The estimate value of digestible lysine was 0.662% ± 0.03 for Phase I and 0.609% ± 0.004 for Phase II.

Made available in DSpace on 2017-07-10T15:14:46Z (GMT). No. of bitstreams: 1 Vander Silveira.pdf: 1631323 bytes, checksum: 98ee5edf851d1f5877f2bfc766c109ab (MD5) Previous issue date: 2012-02-17 / This study aimed to develop and evaluate an electrolytic reaction system for the production of HHO gas. The HHO gas, also known as Brown s gas or hydroxyl gas, can be used together with liquid fuel in Otto and Diesel cycle engines, to reduce their consumption. To conduct the study was built an electrolytic reactor with 360L steel plates in an acrylic vat. It was evaluated the performance of the electrolytic reactor, using the electrolytes of sodium hydroxide and potassium hydroxide. The findings allowed to conclude that the reactor showed better energy performance in the production of HHO gas when using sodium hydroxide as electrolyte / Este trabalho teve o objetivo de desenvolver e avaliar um sistema de reação eletrolítica para a produção de gás HHO. O gás HHO, também conhecido como gás de Brown ou gás hidróxi, pode ser utilizado concomitantemente com combustíveis líquidos em motores ciclo Otto e ciclo Diesel, visando à redução do consumo destes últimos. Para a realização do trabalho foi construído um reator eletrolítico com placas de aço 316L em uma cuba de acrílico. Avaliou-se o desempenho do reator eletrolítico, utilizando-se os eletrólitos hidróxido de sódio e hidróxido de potássio. Os resultados encontrados permitiram concluir que o reator apresentou melhor desempenho energético na produção de gás HHO quando se utilizou o hidróxido de sódio como eletrólito.

Vocalisations of the endangered Brown Kiwi (Apteryx mantelli) are currently used in a nationwide monitoring program to assess the health of a number of small remnant populations. Only an estimate of population health can be obtained from these surveys. This has to form the basis for a number of critical management decisions. The ability to identify kiwi individually during monitoring would greatly improve the accuracy and quality of information obtained and provide a wider base of knowledge when management decisions are made. This study produces a detailed description of the male and female kiwi call, including duetting and seasonal variations. It then explores whether kiwi demonstrate individually distinctive vocalisations, which could be used in conservation management of kiwi.Calls from seven male and four female kiwi were recorded from Rarewarewa, Whangarei between the 5th of May 2003 to the 31st of April 2004. Two call variables (call duration, number of syllables), two temporal syllable variables (syllable duration, syllable gap duration) and five syllable spectral variables (frequency with the most amplitude, high frequency, low frequency, start frequency, end frequency) were measured from 48 male and 14 female calls. Variables from each call were used to describe and classify calls using one way repeated measures ANOVAs and Discriminant Function Analysis. Males contained on average 24 syllables and females containing on average 22 syllables, with calls from both sexes lasting on average 28 seconds. Male and female kiwi calls differed in multiple spectral, temporal and structural features. Dueting rates and behaviour differed between pairs. Some pairs almost always called in duets, whereas others never dueted. Dueting behaviour also changed seasonally with fewer duets occurring in the non-breeding season and with females initiating more duets in the breeding season. Call structure did not differ between the breeding and non-breeding season. Although the sample size was not sufficient to test for this.Statistically significant differences occurred among nearly all variables between individual male and female kiwi calls, despite statistically significant difference occurring between syllables within calls. Frequency variables were the most important variables in discriminating between individuals, but multiple spectral and temporal variables were needed to separate all individuals. Discriminant Function Analysis was able to correctly classify 87.5% of male and 85.7% of female calls correctly when using the means of the seven syllable variables and the two call variables and 68.2% of male and 66.8% when using the values from each syllable. The latter was improved to 85.9% of male calls correctly classified when only 3 syllables from the middle of the calls were used in DFA, reflecting the variation found at the beginning and end of calls.Brown kiwi show strong signs of individually distinctive vocalisations, which remained consistent over a one year period. The conservation implications of individually distinctive vocalisations and how this feature could be incorporated into the current monitoring of kiwi are discussed.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2005. / Thesis documentation sheet inserted. Appendix includes six papers and manuscripts co-authored with others. Also issued electronically via World Wide Web in PDF format; online version lacks appendix of papers.

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