Dissertations / Theses on the topic 'Male sheep'

[Truncated abstract] Reproductive activity is affected by external factors such as photoperiod, social cues, stress and nutrition, all of which can alter the pulsatile activity of the GnRH neurons, which is the major neuroendocrine system used by the brain to control gonadal function. In the male Merino sheep, nutrition is one of the most powerful factors that affect pulsatile LH secretion, used commonly to bioassay GnRH neuronal activity. More accurately, the reproductive system responds to “metabolic status”, rather than “nutrition”, and the three factors that contribute to metabolic status are food intake, the amount of body reserves and the rate of energy expenditure ... In this thesis, I tested the general hypothesis that the metabolic hormones and hypothalamic neuropeptides that are known to control food intake also mediate the effect of metabolic status on the activity of the GnRH neurons ... In conclusion, the results from my experiments provide some insight into the mechanisms by which metabolic status affects reproductive activity in male sheep. Plasma insulin, which changes with alterations in metabolic status, appears to play a critical role in the regulation of GnRH neuronal activity. The level of leptin seems to have a permissive role only in lean animals. Orexins acting via OX2 receptors could be involved in the activation of reproductive function following an acute increase in nutrition. However, the neuropeptidergic systems can not be ruled out because they might be involved in very early steps of responses to nutrition.

[Truncated abstract] The activity of the reproductive endocrine axis is the result of interactions among many organs and tissues, particularly the hypothalamus, pituitary gland and gonad. However, it depends on more than the communication between anatomical structures because it is also affected by genotype, internal factors (e.g., metabolic inputs) and external factors (e.g., photoperiod, socio-sexual cues, stress, nutrition). This multifactorial complexity makes it difficult to use animal experimentation to investigate the pathways and mechanisms involved. Therefore, in this study, I have turned to mathematical modelling. The general hypothesis was that, by modelling the hormonal feedback loop that links the hypothalamus, pituitary gland and gonad, I would be able to discover the critical control points in this homeostatic system. This would allow me to inform and direct research into the processes that control reproduction, including inputs from environmental factors. My studies began with the development of a model of the negative feedback loop through which testosterone controls the secretion of pulses of gonadotrophin-releasing hormone (GnRH) by the hypothalamus. The model incorporated two critical factors: testosterone concentration and a time delay in the inhibition of the activity of the GnRH 'pulse generator' by testosterone. The general assumptions were: i) there are two positive feedforward processes (GnRH pulses stimulate LH pulses, and, in turn, LH pulses stimulate testosterone secretion); ii) testosterone exerts negative feedback that reduces the frequency of GnRH pulses. The model incorporated a group of equations that represent the GnRH pulse generator, through which the inhibitory effect of testosterone acted to reduce GnRH pulse frequency. Simulations were run with various values for the time delay in feedback and, as model development progressed, the simulations were extended to include combinations of time delays and levels of sensitivity of the GnRH pulse generator to inhibition by testosterone. The output of the simulations showed clearly that a time delay in negative feedback, as well as the concentration of testosterone, can greatly affect the frequency of GnRH pulses and the shape of the GnRH secretory profile. Importantly, the effect of the time delay depends on the sensitivity of the pulse generator to testosterone. In addition, the simulations suggested two additional components that might be involved in the control of the GnRH pulse generator: i) a delay in the rate of adaptation to a change in steroid feedback; and ii) a minimum pulse interval (maximum frequency). These studies iii therefore suggest that the regulation of the activity of the GnRH pulse generator, and thus the frequency and profile of GnRH and LH pulses, requires interactions among these four components. These interactions should be tested in animal experimentation. In the next stage, I extended the model so I could test whether the feedback delay might involve the process of aromatization in which testosterone is converted to oestradiol at brain level. ... This information can be used to direct future experimental studies that will help us to understand the factors that underlie the dynamic behaviour of the hypothalamic and pituitary systems that control reproduction.

Two experiments determined the effects of flaxseed supplementation on reproductive parameters in sheep. In experiment one, 240 multiparous Rambouillet ewes were assigned to one of two treatments: basal ration alone or basal ration with a Flaxlic® Sheep Tub offered over 35 days. Serum was collected weekly for progesterone (P4). Flaxseed supplementation did not improve progesterone concentration or reproductive parameters (P ≥ 0.26). In experiment two, 120 Rambouillet ram lambs were assigned to one of two treatments: basal ration alone or basal ration with a Flaxlic® Sheep Tub offered over 112 days. Scrotal circumference measurements, serum for testosterone, and semen were collected on day 84 and 112. Day effects were found for select semen measurements, testosterone, weight, and scrotal circumference (P ≤ 0.05). There was no effect of treatment on testosterone concentration (P = 0.99) or any semen quality characteristics (P ≥ 0.33). Overall, tub supplementation did not alter reproductive ability.

The purpose of this thesis is to determine: 1) the consequences of nutritionally-mediated placental growth restriction on foetal growth, pituitary gonadotrophin gene expression and gonadal development at Days 77, 104 and 128 of gestation; 2) the effect of prenatal growth restriction on the subsequent onset of puberty in female and male lambs. Embryo transfer (ET) was used to achieve singleton pregnancies in peripubertal adolescent sheep. Immediately after ET, ewes were offered either a high (H, 2-2.5 x maintenance) or moderate (M, 1.25 x maintenance) level of nutrient intake until slaughter at Days 77, 104 and 128 of gestation or until delivery at term (~Day 145). High maternal intakes resulted in restricted placental mass at all gestational stages (p<0.05 to p<0.00l) and were associated with a reduction in foetal size during late gestation (p<0.0l) and at term (p<0.001). In the male foetus, pituitary gene expression for LHß, FSHß, GnRH-receptor and oestrogen-receptor, and testicular development were not perturbed by maternal overnutrition until late gestation when growth of the male foetus per se was reduced and gonadotrophin-dependent mechanisms appeared to regulate testicular development. Female foetuses from H dams exhibited fewer primordial and primary follicles at Days 104 (p<0.05) and 128 of gestation. Pituitary LHß expression was affected by overnutrition of the dams only at Day 128 of gestation (p<0. 05). It is concluded that maternal overnutrition probably had an adverse effect on ovarian development via gonadotrophin-independent mechanisms during the first two thirds of pregnancy. Prenatal growth restriction retarded the endocrine and physical onset of puberty in male lambs. The pre-pubertal rise in peripheral testosterone concentrations was delayed (p<0.01), peak testosterone concentrations were reduced (p<0.05) and testicular volume was lower (p<0.0l) in male lambs born to H compared to M dams. In contrast, the capacity of nutritionally growth-restricted female lambs to respond to natural photoperiod and to begin cyclical ovarian activity, as determined by measurement of plasma progesterone concentrations, was similar to normal birthweight ewe lambs.

A fim de avaliar formas de associações do resíduo úmido de cervejaria com uso de aditivos no processo de ensilagem ; e desempenho e digestibilidade de cordeiros a partir a das associações, foram distribuídos em delineamento inteiram ente casualizado 5 tratamentos com 4 repetições: C: ensilagem de 100% resíduo de cervejaria; PC15: 15% de polpa cítrica; PC30: 30% de polpa cítrica; CS15: 15% de casca de soja; CS30: 30% de casca de soja, adicionados com base na matéria fresca do resíduo de cervejaria. Das silagens foram coletadas amostras para as análises bromatológicas, pH, poder tampão, nitrogênio amoniacal, DIVMS e determinação de ácidos orgânicos (ácidos lático, acético, propiônico, butírico) e perfil microbiológico. Os dados da silagem foram analisados por meio da Eficiência Biológica Relativa (EBR), através da técnica do \"slope ratio\". Para análise in vivo foi verificado o desempenho dos animais e digestibilidade. Os dados foram analisados através do programa computacional Statistical Analysis System (SAS, 2008), considerando efeitos fixos a inclusão de aditivos e os níveis. As médias dos tratamentos foram comparadas por contrastes ortogonais. Houve aumento do teor de MS, carboidratos e poder tampão para os níveis de inclusão; aumento da digestibilidade in vitro da matéria seca; aumento na relação desejável/indesejável de ácido lático/ acético e butírico; aumento da população de bactérias ácido lática, e clostrídeos da silagem. Houve melhora no desempenho com a adição de casca de soja e polpa cítrica e na digestibilidade in vivo de MS, sendo os melhores resultados encontrados, em conjunto, para o tratamento da silagem com inclusão de 30% de polpa cítrica.
In order to evaluate the production of silage and the use of additives in the process of silage of brewery residue, they were distributed in a completely randomized design treatments 5 and 4 repetitions: C: silage 100% brewery residue; PC15: 15% of citrus pulp; PC30: 30% of citrus pulp; CS15: 15% of soybean hulls; CS30 mice: 30% of soybean hulls- added on the basis of the fresh of the residue of brewery. The silage samples were collected for the qualitative analysis, pH, buffer, ammoniacal nitrogen, IVDMD and determination of organic acids (Lactic acid, acetic acid, propionic, butyric) and microbiological profile. The Relative Biological Efficiency (RBE) was calculated by the slope ratio technique For in vivo analysis was verified the performance of the animals and digestibility.The data were analyzed by the Statistical Analysis System (SAS, 2008), whereas fixed effects the inclusion of additives and levels. The treatment average was compared by orthogonal contrasts There was an increase in the content of MS, carbohydrates and power buffer from the inclusion; increase in vivo digestibility of DM and increase of the population of lactic acid bacteria, clostridium; IVDMD, and the best results, together, for the treatment of silage with inclusion of 30% of citrus pulp.

FundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
A tese à composta por dois capÃtulos. O primeiro capÃtulo inclui o trabalho cujo objetivo foi investigar o potencial uso de pares de transcritos correlativos baseados em microarranjos como marcadores de fertilidade masculina usando a displasia da bainha fibrosa (DFS) como modelo afetado. Atualmente à bastante reconhecido que a tecnologia de microarranjos pode ser limitada pelos custos e que a qualidade dos transcritos permanece relativamente desconhecida. Para responder essas questÃes, nÃs analizamos pares de transcritos estÃveis por qPCR com um processo sistemÃtico de desenho de primers sistemÃtico. Nesse estudo experimental, nÃs utilizamos amostras de homens com fertilidade comprovada e de homens com diagnÃtico de DFS. Nossa abordagem foi baseada nas sequÃncias de primers dos seis genes de interesse, os quais foram desenhados utilizando os programas Oligo7 e Primer3Plus. A especificidade do primer foi inicialmente analisada in silico atravÃs de pesquisas nos bancos de dados ENSEMBL, University of California Santa Cruz (UCSC), e National Center for Biotechnology Information (NCBI) para uso de sequÃncias especÃficas aos genes alvos. A habilidade dos pares de transcritos em classificar as amostras de homens de fertilidade comprovada das amostras de DFS foi avaliada. Nossos resultados mostraram que em conjunÃÃo com a identificaÃÃo de quatro novos pares estÃveis, a comparaÃÃo dos coeficientes de correlaÃÃo dos valores de C(t) dos DSF revelou a interrupÃÃo de quatro pares estÃveis identificados nas amostras de homens normais. Esta seleÃÃo de pares estÃveis resolve a questÃo sobre a DSF. Em conclusÃo, os resultados mostram efetivamente que o desenho de primers e qPCR podem fornecer um ensaio molecular de baixo custo para avaliar a fertilidade masculina. O segundo capÃtulo divide-se em dois estudos e avalia em carneiros os efeitos de uma dieta suplementada com farelo de castanha de caju. No estudo 1, nosso objetivo foi detectar a presenÃa de transcritos para Heat Shock Protein (HSP70), clusterina (CLU), proteÃna semelhante à subunidade alfa do complexo T (TCP1) e proteÃna do complexo T subunidade 8 (CCT8) no espermatozÃide de ovinos, seguindo a mesma metodologia para qPCR utilizada no capitulo 1. As sequÃncias de primers foram desenhadas utilizando os programas Primer3Plus e Oligo Analyzer. Gene para protamina 2 (PRM2) foi usado como controle interno de reaÃÃo. O sÃmen foi coletado de machos pÃberes Morada Nova utlizando eletroejaculador. As amostras selecionadas para extraÃÃo de RNA espermÃtico seguiram as recomendaÃÃes do ColÃgio Brasileiro de ReproduÃÃo Animal quanto aos parÃmetros de motilidade, vigor e concentraÃÃo. Nossos resultados mostraram a presenÃa de mRNA para a HSP70 nos espermatozÃides de ovinos. Maiores estudos sÃo necessÃrios a fim de confirmar ou refutar a presenÃa das chaperonas TCP1 e CCT8 no espermatozÃide ovino. A presenÃa do transcrito da HSP70 no espermatozÃide de ovinos abre perspectivas para estudos futuros sobre os efeitos do mRNA HSP70 no desenvolvimento embrionÃrio, de modo a avaliar se essa expressÃo ocorre de modo espontÃneo, programado e seqÃencial, e se esses mecanismos se refletem na fertilidade e no desenvolvimento embrionÃrio. O segundo estudo tem como principal objetivo avaliar os efeitos de uma dieta contendo farelo de castanha de caju (FCC) na expressÃo de genes relacionados ao metabolismo dos lipÃdios no mÃsculo Longissimus dorsi de carneiros Morada Nova. Vinte carneiros maduros sexualmente foram divididos em dois grupos baseando-se no peso vivo. Os animais foram mantidos em baias individuais. Durante trÃs meses, o grupo castanha (GCA) foi alimentado com raÃÃo contendo FCC, enquanto o grupo controle (GCO) recebeu raÃÃo à base de milho e soja. As duas dietas eram isocalÃricas e isoprotÃicas, adicionadas de suplemento mineral. Os carneiros tambÃm receberam feno de Tifton e Ãgua à vontade. A quantidade de alimento ofertado (raÃÃo e feno) foi ajustada diariamente para sobra de 10%. Sete genes codificantes de proteÃnas envolvidas direta ou indiretamente foram selecionados como alvos, incluindo: GH, ACACA, CAST, CAPN3, LPL, SCD e FASN. Para normalizaÃÃo, foram selecionados cinco genes candidatos: ACTB, GAPDH, RPL4, RPS18 e TBP. Dentre os sete genes alvos selecionados anteriormente, os alvos GH, ACACA e CAST foram removidos. Os dois primeiros foram removidos devido amplificaÃÃo de alinhamento mÃltiplo (baixa especificidade do primers), enquanto CAST apresentou baixa eficiÃncia de amplificaÃÃo. Da lista de gene alvo final, a expressÃo de somente dois genes foi afetada pela dieta, SCD (p<0.01) e FASN (p<0.05), enquanto LPL (p=0,1022) e CAPN3 (p=0,0939) nÃo apresentaram diferenÃa significativa (p<0.05). Os genes SCD e FASN foram reprimidos no GCA comparada ao GCO. Este à o primeiro relato de que uma raÃÃo contendo FCC afetou a expressÃo gÃnica de proteÃnas envolvidas na deposiÃÃo de lipÃdios no mÃsculo em ovinos. Considerando que uma dieta contendo FCC altera a expressÃo de genes lipogÃnicos sem afetar o ganho de peso nem a eficiÃncia reprodutiva de ovinos, faz da castanha de caju uma importante alternativa para o sistema de produÃÃo de ovinos criados em regiÃes tropicais.
This thesis presents two chapters. In the first chapter, its objective was to investigate the potential use of correlative microarray-based transcript pairs as candidate markers for male fertility using dysplasia of the fibrous sheath (DFS) as an affected model. It is widely recognized that microarray technology may be limited by cost and that the quality of the transcript remains relatively unknown. To address these issues, we analyzed the stable transcript pairs by qPCR with a systematic primer design process. On this experimental study, we used men with proven fertility and men with a diagnosis of DFS. Our approach was based on primer sequences for six genes of interest were designed using Oligo7 and Primer3Plus. Primer specificity was initially assessed in silico by searching the ENSEMBL, University of California Santa Cruz, and National Center for Biotechnology Information databases for nontarget complementary sequences throughout the genome. The ability of transcript pairs to classify samples from males of proven fertility away from DFS was assessed. Our results showed that in conjunction with identifying four new stable transcript pairs, comparison of the DFS qPCR C(t) correlation coefficients revealed the disruption of four stable fertile sample transcript pairs. This suite of transcript pairs resolves DFS. In conclusion, the results show that with effectively designed primers, qPCR may provide an affordable molecular assay to assess male fertility status. Second chapter includes two studies regarding evaluations of ram feeded with supplemented diet with cashew nut. On the frist study, our goal was detect transcripts for Heat Shock Protein (HSP70), Clusterin (CLU), Ovis aries T-complex protein 1 alfa subunit-like protein (TCP1) e Ovis aries chaperonin containing TCP1, subunit 8 (theta) (CCT8) on ram sperm by. For primer designing we used published ESTs from NCBI and manually annotated by us using Primer3Plus and OligoAnalizer. PRM2 was used as internal qPCR control. Semen samples from mature Morada Nova ram were collected by eletroejaculator, washed in PBS and prepared for further RNA extraction. Selected samples followed quality recommendatios from ColÃgio Brasileiro de ReproduÃÃo Animal regarding motility, vigor and concentration. Our results showed presence of mRNA HSP70 on ram sperm and they can possible be envolved in early embryo development, oocyte activation and post fertilization events. Further analyses will be necessary to confirm presence of TCP1 and CCT8 on ram sperm. Our findings indicate new perpectives about the effects of these chaperones during embryo development mesuring if its expression reflects male fertility on the early embryo development. On the second study the the main goal is to evaluate the effects of a lipid-enriched diet containing cashew nut brain on the expression of genes related to lipid metabolism in the longissimus dorsi muscle of Morada Nova rams. Twenty sexually mature and reproductively sound rams were divided in two groups based on ram live weight, and each ram was kept on individual pens. During three months, group 1 (G1) rams were fed with a lipid-rich diet, containing cashew nut bran (CNB), while group 2 (G2) was fed with a meal based on corn and soy. Both diets were isocaloric and isoproteic, and had a mineral mix added-in. The rams also were offered Tifton grass hay and had free access to water. The amount of diet offered (ration plus hay) was adjusted everyday to a maximum waste of 10%. Seven genes coding for proteins directly or indirectly involved in lipid metabolism were initially selected as targets, incluiding GH, ACACA, CAST, CAPN3, LPL, SCD, and FASN. Also, five genes were selected as reference genes, ACTB, GAPDH, RPL4, RPS18 and TBP. From the seven genes originally selected as targets, GH, ACACA and CAST were removed, leaving the final list with four targets. The first two genes were removed due to alternative pairing of the primers (low specificity), while CAST showed low amplification efficiency during PCR reaction. From the final target list, the expression of only two genes was affected by diet, SCD (p<0.01) and FASN (p<0.05), while LPL (p=0,1022) and CAPN3 (p=0,0939) were not different at the p<0.05 level. Both SCD and FASN genes were down-regulated in G1 (lipid-rich diet containing CNB) compared to G2. These genes are involved in lipogenic pathways, related to tissue lipid deposition; therefore, these results were expected. This is the first time that a fat-rich diet based on CNB was shown to affect gene expression of proteins involved in fat deposition in carcass muscles of rams. Longissimus dorsi is one of the finest meat cuts. Considering that human diets rich in poli-unsaturated fatty acids (PUFA) can decrease the risk of heart and other chronic diseases, a change in the fatty acid profile of this muscle could contribute to a healthier diet, aggregating value to the end-product of the lamb meat market. The effects of CNB-based diet on the gene expression of SCD and FASN support the notion that such diet, as previously shown for other sources of lipid in ruminants, can potentially change the fatty acid composition of L. dorsi, but this hypothesis needs to be experimentally verified by profiling fatty acids in animals fed CNB versus carbohydrate-based diets. CNB use as an ingredient in animal feeding is environmentally-friendly, since it contributes to by-product recycling from the agroindustrial plants in Northeast Brazil. Also, considering that CNB-based diet changes lipogenic gene expression without affecting weight gain or reproductive status of the rams, as shown in another work from our team, makes CNB a very important alternative food in ram production systems in tropical regions.

L'os és un teixit connectiu altament organitzat i especialitzat, la funció principal és la mecànica, proporcionant l'afecció als músculs i per tant permetent que el cos es mogui. Actualment, el tractament quirúrgic estàndard es basa en la immobilització i la introducció d'empelts ossis però presenta algunes complicacions, com ara les infeccions, les no unions i la morbiditat de la zona donant. Avui en dia, milions de pacients pateixen defectes ossis i en concret, als EEUU es diagnostiquen entre 10.000 i 20.000 nous casos d'osteonecrosi del cap de fèmur (ONFH) a l’any. La medicina regenerativa (RM) i l'enginyeria tissular (TE) són dos camps de la ciència que es centren en el desenvolupament de teràpies per reemplaçar i regenerar els teixits perduts o danyats per millorar la qualitat de vida del pacient. La combinació de biomaterials, cèl·lules i senyals és l’eina clau per al desenvolupament d'un producte RM i TE. Un dels camps més desenvolupats en RM és la medicina regenerativa ortopèdica, en concret per al teixit ossi. Hi ha diferents estratègies que combinen cèl·lules autòlogues amb matrius que han demostrat certa eficàcia en el tractament de lesions òssies. Després de la fase de descobriment de nous medicaments de teràpia avançada, i per tal d’aconseguir el registre del nou producte, hi ha la fase de desenvolupament, que inclou la realització d'estudis preclínics (fet per dur a terme la prova de concepte, la seguretat i toxicologia) i els estudis clínics. En primer lloc es van determinar i caracteritzar els components de la preparació d’enginyeria tissular (TEP) amb la finalitat d’obtenir un producte estandarditzat. Aquesta preparació consisteix en un component cel·lular que són les cèl·lules mesenquimals estromals (MSC), tant humanes com ovines unides en una matriu de partícules òssies desantigeneïtzades i liofilitzades. Es va realizar un model de defecte ossi de mida crítica (CSBD) en ovella amb la finalitat d'investigar l'efecte de la TEP en una situació extrema, i es va demostrar la seva seguretat i capacitat per sintetitzar nou os i remodelar l’os existent. Seguidament la TEP es va provar en un model animal rellevant de translació de la malaltia òssia basat en el mètode reportat per Vélez i col·laboradors per a la modelització de ONFH en ovelles demostrant la seva eficàcia i seguretat. També s’ha demostrat que les MSC estan involucrades en la síntesi d'os nou ja que es van trobar progenitors ossis marcats després del tractament de la ONFH, tot i així no es poden descartar els mecanismes paracrins. Per tant, el desenvolupament de la TEP podria contribuir en general a la RM per tal de satisfer les exigències d'una societat que envelleix.
Bone is a highly organized and specialized connective tissue, whose main function is the mechanics, providing attachment to muscles and therefore allowing the body to move. Currently the gold standard surgical treatment is based on the immobilization and introduction of bone grafts but it presents some complications, such as infections, non-unions, and donor site morbidity. Nowadays, millions of patients are suffering from bone defects and specifically, 10,000 to 20,000 new cases of osteonecrosis of femoral head (ONFH) are diagnosed only in the USA every year. Regenerative medicine (RM) and tissue engineering (TE) are two areas of science fields focused on the developing of therapies to replace and regenerate lost or damaged tissues to improve the quality of life the patient. The combination of biomaterials, cells and signals is the key tool for the development of a RM and TE product. One of the most developed fields in RM is the orthopedic regenerative medicine, in specifically for bone tissue. There are different strategies combining autologous cells with scaffolds that have shown some efficacy for treating bone injuries. After discovery phase of any new advanced therapy medicinal products, there is the development phase that includes the conduction of preclinical studies (made to perform the proof of concept, safety and toxicology) and clinical studies before the registration of the new product. First the components of the tissue engineered preparation (TEP) were determined and characterized in order to have a standardized material. It consists in MSC (mesenchymal stromal cells) both human and ovine sources are used as a cellular component seeded in a deantigenized and lyophilized bone particles as a scaffold. Then critical size bone defect (CSBD) was modeled in sheep in order to investigate the effect of the TEP in an extreme situation, demonstrating its safe ability to synthesize new bone and bone remodeling. Afterwards TEP was tested in a relevant translational animal model of bone disease based on the method reported by Velez and collaborators for modelling ONFH in sheep demonstrating its efficacy and safety. Also demonstrating that MSC were involved in the synthesis of new bone, because labeled bone progenitors are shown after ONFH treatment, although paracrine mechanisms can not be discarded. Therefore, the development of TEP could contribute to the overall RM to meet the requirements of an aging society.

The objective of this research was to establish a relationship between arc spot weld shear strength and the arc time used to form the weld. Lap shear tests were performed on both 3/4 in. and 5/8 in. nominal diameter welds. Each weld was formed in one-, two-, or four-layers of sheet steel ranging from 22 gauge (0.028 in.) to 16 gauge (.057 in.). Three distinct time series were tested for each unique weld size, thickness of sheet steel and layer configuration. The first of these series were the full-time welds. The two remaining series, 2/3-time and 1/3-time welds, had arc times equal to 2/3 and 1/3 of the average full-time weld arc time, respectively. Both weld shear strength tests and weld sectioning were performed for each series of weld. Strength tests were performed on a minimum of three specimens from every weld series. If the strength of any specimen deviated by over ten percent from the mean strength, an additional specimen was tested, helping to better understand the true behavior of the weld. Comparisons were made between the strengths of full-time, 2/3-time and 1/3-time welds. Comparisons were also made between the observed strength of each weld and the strengths calculated using the 2001 AISI Specification. Each sectioning test involved measuring and documenting the visual diameter, average diameter and effective diameter of the weld. Weld penetrations were also documented as sufficient or insufficient and any porosity was noted. A single sectioning test was performed for each full-time series, while three were performed for every 2/3-time and 1/3-time series. The data taken from the strength tests and the sectioning samples proved that welds formed using reduced arc times were considerably smaller and weaker than full-time welds. The tests also proved that proper penetration is not dependent on the arc time, but is instead a function of the welding current and sheet steel thickness.
Master of Science

Thermoplastic prepregs that are also known as organo sheets are processed in presses and formed to half shells. Larger components can be produced by joining the half shells, which results in hollow bodies. However, current manufacturing technologies allow only cap profile shaped joints, which cause fiber deflections in the joint plane. This presentation shows that overlapping infrared welds in organo sheets enable weld strengths close to the interlaminar shear strengths of the unwelded materials and thus a fiber utilization across the joint plane. By using high welding pressures, a matrix depletion and a change of the fiber alignment in the weld plane may occur which causes low weld strengths. Therefore possibilbites to optimize the weld strengths are shown and one possible process variants for the manufacturing of hollow bodies by infrared welding is introduced.

The diploma thesis focuses on analyzing current information system of small company and proposal of modifications. Improvements of current batch control sheet system are designed as extensions of already implemented functionality and integration of attendance sheet which is related to it. Within the frame of modifications thesis proposes extensions of database model with emphasis to simplicity and complexity of target solution.

Bakgrund: Dagens marknader har med tiden tenderat att bli mer globala vilket i sin tur har ökat konkurrensen mellan företag. Detta har inneburit att många industriorganisationer har behövt förändra sig för att vara konkurrenskraftiga på marknaden. Ett koncept som idag genomsyrar många företag är lean vilket bygger på att maximera användandet av sina resurser, eliminera slöserier och skapa en effektivare tillverkning. Genom att arbeta med lean kan företag uppnå snabbare genomloppstider. Syfte: Syftet med studien är att kartlägga Press Kogyos propellerprocess för att kunna identifiera icke-värdeadderande aktiviteter i processen. Vidare kommer studien bidra Press Kogyo med förslag gällande hur en effektivare material- och produktionsstyrning kan reducera genomloppstiden i propellerprocessen. För att studien ska uppnå teoretisk relevans är ytterligare ett syfte med studien att bidra med teori kring hur tillverkande företag, med en funktionell layout, kan reducera de nackdelar som finns med layouten med effektivare material- och produktionsstyrning. Genomförande: Studien har delats upp i tre forskningsfrågor. De två första forskningsfrågorna var specifikt inriktade mot det studerade företaget medan den tredje forskningsfrågan var mer generellt ställd mot tillverkande företag med funktionell layout. Studien har genomförts som en fallstudie och präglats av kvalitativa forskningsmetoder. Empiriska data har samlats in genom intervjuer, observationer samt en fokusgrupp. För första forskningsfrågan skapades processkartor och VSM-kartor. Dessa i samband med diverse intervjuer låg till grund för att identifiera icke-värdeadderande aktiviteter/slöserier i propellerprocessen vilka påverkade genomloppstiden. För forskningsfråga två applicerades teori kring material-och För tillverkande industriföretag kan en reducering av genomloppstid generera diverse fördelar. Några av dessa fördelar är: minskat antal produkter i arbete, bättre kvalité, minskade kostnader, bättre prognoser, ökad flexibilitet samt minskad ledtid gentemot kund. Press Kogyo har under en längre period upplevt en problematik kring en av deras processer. Problematiken har legat i att de inte vetat om vilka icke- värdeadderade aktiviteter som finns i processen samt hur de påverkar genomloppstiden.   produktionsstyrning i syfte att reducera de icke-värdeadderande aktiviteterna/slöserier som identifierats och följaktligen reducera genomloppstider i processen. Gällande forskningsfråga tre genomfördes intervjuer med det studerade företaget och ett annat tillverkande företag med funktionell layout. Författarna ämnade att genom dessa intervjuer besvara hur tillverkande företag med en funktionell layout kan reducera de nackdelar som finns med den layouten med hjälp av effektiv material- och produktionsstyrning. Slutsats: I studien identifierades sju slöserier där väntan ansågs vara det slöseri vilket mest påverkade genomloppstiden i propellerprocessen. För att eliminera alla slöserier och framförallt väntan applicerades teori kring material- och produktionsstyrning med fokus på production activity control (PAC). Den teori vilken användes skapade också en teoretisk modell vilken kan vara en bra grund när företag med funktionell layout vill effektivisera sin planering. Vissa delar av den teoretiska modellen användes också senare i studien där den användes för att reducera de nackdelar vilka kan finnas med en funktionell layout.
Background: Today's markets have over time tended to become more global, which in turn has increased competition between companies. This has meant that many industry organizations have had to change in order to be competitive in the market. A concept that today permeates many companies is the lean practice, which is based on maximizing the use of resources, eliminating waste, and creating more efficient production. By working with lean, companies can achieve faster throughput time. For manufacturing industrial companies, a reduction in throughput time can generate various benefits. Some of these advantages are: reduced number of products in work, better quality, reduced costs, better forecasts, increased flexibility and reduced lead time towards customers.Press Kogyo has for a long period experienced problems with one of their processes. The main problem has been that they do not know what non-value-added activities/waste that can be found in the process and how these activitiesaffect the total throughput time of the process. Purpose: The purpose of the study is to map Press Kogyo's propeller process in order to be able to identify non-value-adding activities in the process. Furthermore, the study will provide Press Kogyo with proposals regarding how more efficient material and production control can reduce the throughput time in the propeller process. In order for the study to achieve theoretical relevance, another purpose of the study is to contribute with theories about how manufacturing companies, with a functional layout, can reduce the disadvantages of the layout with more efficient material and production control. Methodology: The study has been divided into three research questions. The first two research questions were specifically aimed at Press Kogyo, while the third research question was more generally directed at manufacturing companies with a functional layout. The study was conducted as a case study and was characterized by qualitative research methods. Empirical data has been collected through interviews, observations, and a focus group. For the first research question, process maps and VSM maps were created. This together with various interviews created the foundation for identifying non-value-adding activities/waste in the propeller process which affected the throughput time. For research question two, theory of material and production control was applied in order to reduce the non-value-adding activities/waste and consequently reduce throughput time in the process. Regarding research question three, interviews were conducted with Press Kogyo and another manufacturing company with a functional layout. The authors intended to, through these interviews, find answers to how manufacturing companies with a functional layout can reduce the disadvantages of the layout with the help of efficient material and production control. Conclusions: In the study, seven wastes were identified where “wait” was considered to be the waste that affected throughput time the most in the propeller process. To eliminate all waste and specifically the waste “wait”, methods and theories regarding material and production control was applied with a focus on production activity control (PAC). All the different theories that was used also created a theoretical model which can be a good basis for planning when companies with a functional layout want to find ways tostreamline their planning. Some parts of the theoretical model were also used later in the study where it was used to reduce the disadvantages that may exist with a functional layout

Diploma work inquires processing of financial statements according International Financial Reporting Standards IFRS and also according current legal adaptation of financial statements in Czech Republic. The work reveals crucial differences in financial reporting of concrete Small Enterprises Company. It demonstrates the influence of financial reporting on income. The work points out necessity of harmonization of national accounting standards with IFRS.

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, School of Physiology, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2018.
In Sub-Saharan Africa, the cost of producing livestock products is increasing due to the use of imported soyabean meal (SBM) as a dietary protein source in feeds. Reliance on the costly SBM can be reduced by developing alternative dietary protein sources for feeds. Seeds from indigenous trees are potential sources of nutrients including protein. In a series of experiments, the potential of Marula nut meal (MNM) to substitute SBM in lamb fattening diets was evaluated. Chapter 3 characterised and compared the nutrient and anti-nutrient composition of two MNMs (MNM1: produced using hydraulic filter press, MNM2: produced using cold press) and SBM. The MNMs’crude protein (CP) content, which ranged from 33% (MNM1) to 39% (MNM2), was lower than that of SBM (51%). The MNMs’ essential amino acid content ranged from 40 to 70% compared to that of SBM. The gross energy (GE), ether extract (EE) and total monounsaturated fatty acid (TMUFA) content of the MNMs were significantly higher (P<0.05) compared to that of SBM. The MNMs had a higher (P < 0.05) phosphorus and magnesium content than SBM. Compared to SBM, MNM2 had a higher oxalate and phytate-phosphate content, but a lower saponin and tannin content (P<0.05). MNM2 was used in the in vivo study (chapter 4) as a dietary protein source, due to it having a higher CP content and in vitro digestibility compared to MNM1. Chapter 4 interrogated the effects of MNM2: denoted as MNM, as a dietary protein source on growth performance, feed efficiency and health of Dorper lambs. Dietary MNM neither affected the growth, feed efficiency nor the liver and kidney function of the lambs. In chapter 5 the effect of dietary MNM2: denoted as MNM, due to its higher CP content than MNM1, was evaluated on meat quality. Substituting SBM with MNM at 0, 50 and 75% resulted in meat with high CP (P<0.05) but low EE content while substituting at 25 and 100% resulted in meat with high EE (P<0.05) but low CP content. Dietary MNM significantly increased the total saturated and TMUFA concentration in the meat. Complete substitution of SBM with MNM yielded fatty meat rich in oleic acid, manganese and selenium (P <0.05). The MNM can replace SBM in lamb fattening diets without compromising growth, feed efficiency, liver and kidney function and meat quality. However, substitution of SBM with MNM at high inclusion levels results in increased lipid content in the meat.
LG2018

Typescript.
"April 1987."
Includes bibliograpical references (leaves 160-194).
xii, 194 leaves : ill. ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Presents direct comparative information on growth and endocrinological aspects of reproductive development in intact and gonadectomized male and female Merino lambs born in autumn and treated prepubertally with either a non-aromatizable androgen (trenbolone acetate) with higher androgenic potency than testosterone, oestradiol -17beta(oestradiol), or a combination of these two steroid hormones.
Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1988

碩士
國立虎尾科技大學
材料科學與綠色能源工程研究所
102
PEMFC is a perfluorosulfonic acid type solid polymer electrolyte, a platinum / carbon electrocatalyst, Purifying recombinant or hydrogen gas as fuel, air or pure oxygen as the oxidant. Graphite or a metal plate surface modified with a gas flow channel as a bipolar plate, bipolar plate with the function of the reactive gas transport, both sides are machined or uniform distribution of the reaction gas flow field channels, In order to ensure uniform distribution of the reaction gas in the electrodes. In this research, the carbon fiber prepreg material, carbon fiber woven with graphite powder, graphite, aluminum foil laminated together with a mixture, by hot-press molding process. The purpose of this paper is to study the extent of the carbon fiber woven fabric density, powder type and aluminum foil on the mechanical and electrical properties of the expanded graphite bipolar plates. From the results, the addition of expanded graphite, graphite powder significantly improved plane conductivity than the original composite board, For the mechanical properties had no significant effect. Join the 3K、 12K carbon fiber woven to produce the composite panels, because of the uneven surface to produce the effect on the electrical properties, and after adding aluminum foil for improved heat conduction effect, but will let conductivity deteriorates. Based on the above results, to add a different powder in carbon fiber prepreg, have a conductive path is formed between carbon fibers, for plane conductivity, penetration resistance with good enhance results. The results reveal that the fuel cell with carbon fiber prepreg * 6 + graphite(20％epoxy) has the great current density of 1054 mA/cm2 occurs at 0.28 V, and the highest power density of 295.68 mW/cm2 occurs at 0.48 V.

The analysis of management of sheep and goat breeding on the organic farm is the main aim of my thesis. The herd was examine at the Slunečná organic farm in the Šumava Mountains. The animals were monitored during grasing season by force of metod ethology monitoring. Sheep and goats were monitored and it was done four times for always 24 hours during a grazing period. The method of the direct monitoring was used and the base categories of the behaviour (food intaking, lying, standing and moving) were written down by an interval method - the interval took 10 minutes. The comfortable, mother's, social and sexual behaviour were writen down as well. Gained data from single sighting was expressed absolute and percentage share form total tables and graphs. The results were interpreted on the basis of the study of special literature and legislation about organic farming and animal ethology. The way of sheep and goats farming was according to an inborn biorhythm and gave the animal free and natural ways of behaviour. The physiological and ethological needs of animals are satisfactory. Sheep and goats have the possibility to graze freely on pastures and they effect positively on the landscape management. They keep grasslands without woody plants and weeds.

This thesis presents problems of small dairy farm on the example of farm operations employed in the South Bohemian Region. It will define the goal of the work focused on the evaluation of the current situation in farm processing of milk with regard to the objective of the Common Agricultural Policy after 2013. The strategy aims to increase the efficiency of agricultural production.

Between 1960 and 1992, American artist George Tsutakawa (1910 – 1997) created more than sixty fountain sculptures for publicly accessible sites in the U.S., Canada, and Japan. The vast majority were made by shaping sheet bronze into geometric and organically inspired abstract forms, often arranged around a vertical axis. Though postwar modernist artistic production and the issues it raises have been widely interrogated since the 1970s, and public art has been a major area of study since about 1980, Tsutakawa's fountains present a major intervention in North America's urban fabric that is not well-documented and remains almost completely untheorized. In addition to playing a key role in Seattle's development as an internationally recognized leader in public art, my dissertation argues that these works provide early evidence of a linked concern with nature and spirituality that has come to be understood as characteristic of the Pacific Northwest. Tsutakawa was born in Seattle, but raised and educated primarily in Japan prior to training as an artist at the University of Washington, then teaching in UW's Schools of Art and Architecture. His complicated personal history, which in World War II included being drafted into the U.S. army, while family members were interned and their property confiscated, led art historian Gervais Reed to declare that Tsutakawa was aligned with neither Japan nor America – that he and his art existed somewhere in-between. There is much truth in Reed's statement; however, artistically, such dualistic assessments deny the rich interplay of cultural allusions in Tsutakawa's fountains. Major inspirations included the Cubist sculpture of Alexander Archipenko, Himalayan stone cairns, Japanese heraldic emblems, First Nations carvings, and Bauhaus theory. Focusing on the early commissions, completed during the 1960s, my study examines the artist's debts to intercultural networks of artistic exchange – between North America, Asia, and Europe – operative in the early and mid-twentieth century, and in some cases before. I argue that, with his fountain sculptures, this Japanese American artist sought to integrate and balance such binaries as nature/culture, intuition/reason, and spiritual/material, which have long served to support the construction of East and West as opposed conceptual categories.
Graduate