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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.
241

Étude de l’expression des cytokines et métalloprotéases dans les tissus péri-implantaires inflammatoires et rôle potentiel du titane dans les péri-implantites / Cytokines & metalloproteases expression in peri-implant inflammatory tissues and the potential involvement of titanium in peri-implantitis

Ghighi, Maxime 04 December 2017 (has links)
Les péri-implantites se caractérisent par une destruction inflammatoire irréversible des tissus qui entourent l’implant dentaire. Leur pathogénie est proche des parodontites, maladies inflammatoires chroniques d’étiologie bactérienne entrainant une destruction irréversible de l’os alvéolaire soutenant les dents. Cependant, la réponse inflammatoire et la résorption osseuse diffèrent entre péri-implantites et parodontites. De plus, les traitements conventionnels non chirurgicaux ne sont pas efficaces pour le traitement des péri-implantites. L’objectif de notre travail est d’analyser les différences entre les médiateurs inflammatoires et cataboliques des tissus péri-implantaires en comparaison aux tissus parodontaux malades après une thérapie conventionnelle non chirurgicale. Nous avons bâti une collection biologique d’explants humains de tissus conjonctifs péri-implantaires ou parodontaux malades. Une analyse Multiplex des milieux conditionnés et histologiques des explants a révélé une expression accrue de l’inhibiteur de métalloprotéase TIMP-2, de l’interleukine IL-10 et du RANK-L dans les tissus péri-implantaires. En accord avec une revue de littérature que nous avons mené dans la seconde partie de notre travail, notre hypothèse est que ces différences s’expliqueraient, tout du moins en partie, par la présence de particules de titane au niveau des tissus péri-implantaires. Notre travail participe à la compréhension de la pathogenèse de la maladie et concourt à l’identification de biomarqueurs potentiels pour le pronostic ou le développement d’approches thérapeutiques. / Peri-implantitis lesions present an irreversible destruction of the peri-implant surrounding tissues. The pathogenic pathway of peri-implantitis is close from the one of periodontitis which is a chronic inflammatory disease caused by a bacterial biofilm leading to irreversible supportive bone destruction around teeth. Still, the inflammatory process and the bone destruction differ between the two diseases. In addition, conventional non-surgical treatments are not effective for the treatment of peri-implantitis. The aim of our work is to analyze the differences between inflammatory and catabolic mediators of peri-implant tissues compared to diseased periodontal tissues after conventional non-surgical therapy. We have constructed a biological collection of human explants of peri-implant or periodontal connective tissue. Multiplex assays of the conditioned media and histological analysis of the explants revealed an increased expression of the TIMP-2 metalloprotease inhibitor, interleukin IL-10, and RANK-L in the peri-implant tissues. In agreement with a review of literature that we conducted in our work, our hypothesis is that these differences can be explained, at least partly, by the presence of titanium wear particles in the peri-implant tissues. Our work contributes to the understanding of the pathogenesis of the disease and contributes to the identification of biomarkers.
242

Protein nutrition of livestock grazing high quality pasture

Madibela, Othusitse Ricky January 2010 (has links)
This thesis describes a series of four experiments designed to evaluate the role of the supply of protein in livestock grazing high quality pasture during mating and during pregnancy. The first two studies investigated the effects of high crude protein content of spring or autumn re-growth pasture on the reproductive performance of dairy cows and of ewes at mating. The last two studies investigated how the dietary supply of protein, body condition and their interactions contribute to the breakdown of immunity during the peri-parturient period in ewes and investigated underlying endocrine mechanisms. In the first study (Chapter 3) cows were blood sampled via the tail vein during the breeding period in spring. Plasma was then analysed for urea concentration. Cows with high plasma urea (HPU) or low plasma urea (LPU) were defined as those with plasma urea concentrations of ≥ or < 44.9 mg/dl respectively. Lactating cows (n = 200) were also categorized into high milk producers (HMP) or low milk producers (LPM) relative to an average daily yield of 26.6 l/d. Pasture clipping showed an average pasture CP (crude protein) content of 223 g/kg DM. Concentrations of plasma urea ranged from 26.6 to 64.4 mg/dl. No correlation was observed between plasma urea concentration and either reproductive indicators or milk parameters. Mean blood urea concentration of HPU cows was 50.8 compared to 38.5 mg/dl in LPU cows. There was a trend for more animals (P = 0.09) in the HPU group than in the LPU group not to return to oestrus. Cumulative pregnancy rate in HPU and LPU was similar except at week 6 after the start of mating when more (P < 0.01) HPU than LPU cows were pregnant. Calving to conception interval, calving interval and interval between conception and first service were similar (P > 0.05) between HPU and LPU cows. Gestation length, calving rate, milk yield and milk components were also similar (P > 0.05) between LPU and HPU cows. There was no difference (P > 0.05) in plasma urea concentrations between HMP and LMP milk producers. However, calving to conception interval, interval between calving and first service and calving interval were longer (P < 0.001), submission rate higher (P < 0.001) and NRR (Non-return rate) higher (P < 0.05) in LMP than HMP. The number of services, the interval between first and second service, gestation length and CR (calving rate) were similar (P > 0.05) between HMP and LMP cows. HMP had lower (P < 0.001) milk protein and fat concentrations than LMP cows. This information indicates that, despite the fact that plasma urea was consistently higher than levels in the literature which have been associated with reduced fertility in dairy cows; no impairment of reproductive performance was observed. In the second experiment (Chapter 4) mature and dry Coopworth ewes were blocked by weight, body condition and previous prolificacy (high, HP vs low twinning frequency, LP) into two groups and thereafter randomly allocated to diet which were designed to provided either 1) high protein (163 g/kg DM, ryegrass/red clover pasture, HPP) or low protein (119 g/kg DM, hay and barley grain, HB) supply at joining. These were designed to provide high and low plasma urea concentration. Over a period of 17 days, ewes recorded as mated were examined by laparoscopy, at which time there was no difference in blood urea concentration (58.6 vs 56.1 mg/dl) between HPP and HB groups. Fifty days after the start of joining the number of foetuses present was counted using ultrasonography. As a consequence of lack of difference in the plasma urea concentration, irrespective of treatment group, individual animals were categorized into high (HU) and low plasma urea (LU) status based on whether plasma urea concentration was higher or lower than the sample mean of 51.5 mg urea/dl. Lambs which weighed greater than the mean plus one standard deviation for their litter size were classified as oversize. Ovulation rate and conception rate were similar (P > 0.05) between HPP and BH and between HU and LU ewes. Ewes with previous high reproductive performance (HP) as would be expected had higher ovulation rate (P < 0.001) and conception rate (P < 0.01) than LP ewes. Embryo losses was not (P = 0.06) different between HB and HPP ewes. Urea category (HU vs LU) did not (P > 0.05) influence embryo mortality. Foetal loss, neonatal loss, total reproductive loss and mean lamb birth weight was were not affected by diet, nor urea category (P > 0.05). Single ovulations had tended (P = 0.08) to contribute to higher embryo loss compared to multiple ovulations, and, single foetuses suffered higher (P<0.001) losses compared to multiples. While the study did not achieve large differences in plasma urea concentrations between diets, the levels of plasma urea operating were high yet reproductive wastage rates were similar to those recorded in the literature. Together with similar apparent lack of effect on a high plasma urea environment, the data suggest either that previous findings from controlled studies have a more complex aetiology or that pastoral animals can adapt to high tissue ammonia/urea status. The third trial (Chapter 5) was designed to provide information on the supply of amino acids to the abomasum from protein supplementation which have previously been found to overcome dietary scarcity associated with limitation of peri-parturient increase in FEC. Twin-suckling ewes were fitted with rumen and abomasal cannulae and grazed a ryegrass/clover sward (C) or the same sward but with a 500 g/h/d protein supplement (S). The trial was designed as a cross-over with two 14 day adaptation periods followed by two five-day digesta-sampling periods. All ewes were treated with anthelmintic 14 days after lambing. Weekly analysis of blood glucose was carried on whole blood and analysis of amino acids in plasma. The flows of amino acids (AA) and dry matter (DM) at the abomasum were measured during both sampling periods using intra-ruminally infused markers. Live weight and faecal egg count (FEC) were recorded weekly. Diurnal variation in AA flow at the abomasum peaked between 12:00 and 15:00 h and was greatest in S ewes. Flows of AA, including DAPA, were increased by supplementation by 16%, while sulphur amino acids (SAA) were the most enhanced (by 21%) and flows of leucine, lysine, glutamine and aspartate were increased by about 20%. There were significant time effects in rumen and abomasal pH (P < 0.01; in both cases in both periods) reflecting increase in pH after 09.00 h. During Period II, rumen pH in digesta of C ewes was significantly higher (P < 0.001) than that of S ewes (6.7 ± 0.05 vs 6.4 ± 0.05 for C and S ewes, respectively). Plasma AA concentrations (P < 0.01) were lower in S ewes 21 days after parturition, but similar (P > 0.05) to those of C ewes at other times. Forty-three days after lambing (after cross over), the order was reversed as plasma methionine and cysteine concentrations of C ewes became low (P < 0.05). These changes in plasma AA were accompanied by changes in body condition score between day 23 and 70 post-partum whereby C ewes lost more body condition than S ewes. There was evidence for a lower FEC in S ewes, being 46 vs. 670 epg, respectively for S and C groups (P = 0.08) 21 days after anthelmintic treatment. There were higher (P < 0.05) blood glucose levels in C compared to S ewes at day +35 relative to lambing which was reversed and significantly higher (P < 0.01) for S ewes by day +56 from lambing (after treatments were reversed). There was no significant effect of treatment on live weight and lamb performance. There are limited data in amino acid supply on lactating ewes on pasture and the present study contributes additional information on the supply of amino acids at the abomasum. The prediction that flow rates that sulphur amino acids may have been enhanced to the greatest degree could be significant since sulphur amino acids are needed for the synthesis of glutathione for immune response. It can be calculated that supplementation to supply the quantities of S-amino acid at pasture would be needed, since it would not be possible for sheep to increase pasture intake to achieve similar S-amino acid flow. Increase in bypass amino acids in S ewes at certain times in the day probably suggests influence by protein supplementation at certain times of the grazing cycle. Reduced plasma free amino acids at day +21 relative to lambing, may indicate sparing of body protein breakdown by protein supplementation. However, the difference in blood glucose on day 35 and day 56 may indicate re-adjustment of hormonal settings, responsible for nutrient partitioning. The last study (Chapter 6) used ewes during the peri-parturient period on pasture. Eighty pregnant ewes were allocated into four groups balanced for anticipated number of lambs. Group 1 had a high body condition score (BCS) of 4.0 which was maintained throughout pregnancy by pasture allowance (HM; n = 20). Group 2 (n= 40) had medium body condition (BCS 3.0) and were split into two subgroups; one was offered pasture to allow gain of condition (MH; n = 20) and the second allowed to lose condition by offering a low grazing allowance (ML; n = 20). Group 3 were thin ewes (BCS 2.4) and pasture allowance was designed to maintain this condition (LM; n = 20). These feeding regimes were maintained for 3 weeks from week -8 of pregnancy. During week -5 to -4 all ewes were acclimatized to a protein supplement (60 g/d). A glucose tolerance test (GTT) was conducted during week -4 after which half of the ewes in each group were offered a protein supplement at the rate of 500 g/d, creating –S and –NS groups. During wk -2, a second GTT was carried out. Animals were treated with an anthelmintic 3 wks before lambing, and were then challenged with a dose of 10 000 Teladorsagia circumcincta larvae on weeks -2 and -1 relative to lambing. Weekly recording of FEC, live weight and body condition was carried out. Lambs were weighed within 24 h of birth and again at 44 and 65 d of age. Computed tomography body scanning was carried out on ewes at weeks -8, -3 and +8 relative to lambing. There were no differences (P > 0.05) in lamb performance due to body condition or protein supplementation. FEC of all groups was low (≈ 9 peg) and there was no (P > 0.05) significant difference between ewes of different body condition or due to effects of protein supplementation. Ewes bearing/bearing multiple lambs had the highest FEC at day -32 and +12 relative to lambing, which was significant (P < 0.05) on the latter date. There were no significant effects of supplementation on parasite status. There were differences in basal plasma glucose concentration between groups (P < 0.001), being highest in HM/S and least in ML/NS ewes and was generally higher (P <0.001) during GTT 2 than GTT 1. Ewes carrying a single foetus had higher (P <0.001) basal glucose than those carrying multiple lambs (2.2 vs. 1.7 mmol/L, respectively). Other plasma glucose response indexes were similar (P <0.05) between groups. There were differences in insulin responsiveness between groups (P < 0.001), being highest in MH/S and least in ML/S ewes. Insulin responsiveness tended (P = 0.06) to be lower during GTT 1 than GTT 2, but was higher (P < 0.01) in ewes carrying singles than multiples. There was tendency for higher though non-significant, basal insulin concentrations in HM ewes. Insulin trends over time after glucose infusion suggest greater insulin response at GTT 1. Basal insulin was not correlated with CT muscle weight. Despite differences in body muscle mass at the start of the trial and differences induced by nutrition during late pregnancy, positive gains in muscle mass occurred during early pregnancy and muscle mass was similar in all groups by day 56 of lactation. Animals with greatest fat content at parturition (HM) mobilised the greatest amount and those with least fat (LM) deposited fat during lactation. Further experimentation may consider the use of the hyperinsulinemic-euglycemic clamp approach to more precisely estimate whether hormonal re-setting through insulin resistance may be involved in relaxation of immunity during the peri-parturient period.
243

Ecological Sanitation : Attitudes Towards Urine Diverting Toilets and Reuse of Nutrients in Peri Urban Areas of Kampala, Uganda. A Case of Kamworkya II Parish

Minze Ngobi, Richard January 2007 (has links)
<p>ABSTRACT</p><p>Billions of people are living without access to safe hygienic means of personal sanitation. The sanitation gap is wide in developing countries where more people are increasingly becoming urbanised. Sanitation related diseases are some of the leading cause of mortality and morbidity among the population in developing countries especially children under age of 5 years. The responsible institutions are faced with challenge to provide suitable and affordable services to this increasing population. In Uganda, the urban poor are residing in the peri urban areas with inadequate sanitation facilities. The provision of conventional sanitation facilities are seen not be sustainable options due to contamination of both surface and underground water sources, congested housing structure and at the same time makes recycling and reuse of nutrients difficult.</p><p>This study investigated attitudes towards urine diverting toilets in one of the peri urban areas in Kampala, with the aim of finding out strategies to improve on awareness of ecological sanitation as well as popularise their use as alternative sanitation. Respondents’ views were collected through face to face interviews with 40 household respondents using a semi structured questionnaire and field observations of the household’s toilet in use as well as solid waste disposal. Four focus group discussions and 6 key informant interviews were also performed.</p><p>The respondents’ acceptance of the urine diverting toilets was relatively positive. Most of the respondents reported that the ecosan toilets are a viable option due to congested housing pattern, desire to own a toilet (for those who never had a toilet before), improved privacy, and convenience among other factors. Respondents who have no urine diverting toilets also preferred urine diverting toilets and expressed their willingness to replicate them. It was also found that residents in Kamwokya II parish prefer a double vault design to one which uses bucket. The findings also reveal that reuse of sanitized urine and faecal matter within the community is not possible since there is no space for urban agriculture. However, the respondents acknowledged a willingness to eat or buy food from a garden fertilized with sanitized urine and faecal matter. It was also found that there are no cultural and religious beliefs against reuse of sanitized urine and faecal matter. Some challenges that affected implementation of the pilot project were people’s reluctance to adopt at the beginning, delayed completion of some facilities and part time employees. Currently there is limited replication of toilets because of low cash income among the residents, delayed completion of some facilities and sceptical views by some residents.</p><p>Among the difficulties faced in use of toilet include forgetfulness by some people to spray ash after defecating, misplaced water entering the toilet vault during cleaning, children playing with the urine container etc. The provision for anal cleansing for Muslims, squat hole covers, closed urine chamber among others were suggested for system improvements. The study recommends more awareness campaigns through social marketing of toilet and reuse of nutrients, modification of design, government’s commitment and household change of behaviours are fundamental for encouraging more adoption and replication of the toilets.</p>
244

Perception on Support Provided to Orphan Children in Foster Care Placement in an Urban City of Windhoek (Namibia)

Nshimyimana, Brigitte January 2008 (has links)
<p>Zambia is a highly urbanized country with 60% of its urban population residing in low cost areas also called peri-urban, slum or informal settlements. The increase in urban population attributed to rapid migration and urbanization due to political and economic changes has taken a toll on service provision as the infrastructure development and service provision has failed to meet the demand. For the 33 peri-urban areas in Lusaka, the water supply and sanitation has been poor, inadequate and unreliable with the coverage being slightly above 50% for water while 90% of the urban population does not have access to the much needed sanitation. The low coverage is a result of lack the financial capacity on the part of the service providers to extend services to un served areas.</p><p>This research focuses on the strategies to provide sustainable water and sanitation services to peri-urban areas to ensure improved accessibility through the expansion of infrastructure and attainment of full cost recovery. In this era of increasing migration to unplanned settlements where the services are inadequate, alternatives to public provision of water and sanitation services need to be put in place. One of the alternatives is the public-private partnership which encompasses the society, private and the civil society. As has been found in the study the best alternative should not only be completely bottom up but should also be more demand driven and be able to provide for greater contributions from the affected communities.</p><p>The hypothesis of the study is to ascertain if provision of water supply to the Peri-Urban Areas (PUAs) can be achieved through the partnership between the water utility and the small scale water providers. Therefore, the objectives of the research are to: evaluate and compare the current service provision to the peri-urban areas by the utility and small scale providers in terms of technical, social and institutional arrangements and determine the best way of ensuring sustained service provision to peri urban areas and show how partnership can be the best solution to improving service delivery to these areas.</p><p>Service provision in PUAs can not be achieved without the involvement of all the stakeholders especially the community who are also the users and whose major role is paying for the service to enhance sustainability. In this study the Small Scale Water Providers (SSWP) users were found to be satisfied with the service provided than the utility users who felt that more needed to be done. The two providers are found to have different strengths which when combined would enhance service provision. The collaboration between utility with its competence in water supply, technical installations, water quality testing and SSWP with theirs in community involvement, cost recovery, effective operation and maintenance and demand driven water schemes have to be merged to achieve the intended goal and it is also an indication that the two can complement each other. Utility should therefore consider opening investment accounts for all the areas so as to detach PUAs needs from the general plan and eventually budget as they would be self sustaining and enhance willingness to pay for the users. The SSWP should therefore be viewed as partners by all and licensing should be considered by the government for the benefit of the urban poor.</p>
245

Expanding Water Service Delivery through Partnership between Water Utility and Small Scale Water Providers in Lusaka, Zambia : A Case of Lusaka's Peri-Urban Areas

Mwandu Siyeni, Yvonne January 2008 (has links)
<p>Zambia is a highly urbanized country with 60% of its urban population residing in low cost areas also called peri-urban, slum or informal settlements. The increase in urban population attributed to rapid migration and urbanization due to political and economic changes has taken a toll on service provision as the infrastructure development and service provision has failed to meet the demand. For the 33 peri-urban areas in Lusaka, the water supply and sanitation has been poor, inadequate and unreliable with the coverage being slightly above 50% for water while 90% of the urban population does not have access to the much needed sanitation. The low coverage is a result of lack the financial capacity on the part of the service providers to extend services to un served areas.</p><p>This research focuses on the strategies to provide sustainable water and sanitation services to peri-urban areas to ensure improved accessibility through the expansion of infrastructure and attainment of full cost recovery. In this era of increasing migration to unplanned settlements where the services are inadequate, alternatives to public provision of water and sanitation services need to be put in place. One of the alternatives is the public-private partnership which encompasses the society, private and the civil society. As has been found in the study the best alternative should not only be completely bottom up but should also be more demand driven and be able to provide for reater contributions from the affected communities.</p><p>The hypothesis of the study is to ascertain if provision of water supply to the Peri-Urban Areas (PUAs) can be achieved through the partnership between the water utility and the small scale water providers. Therefore, the objectives of the research are to: evaluate and compare the current service provision to the peri-urban areas by the utility and small scale providers in terms of technical, social and institutional arrangements and determine the best way of ensuring sustained service provision to peri urban areas and show how partnership can be the best solution to improving service delivery to these areas.</p><p>Service provision in PUAs can not be achieved without the involvement of all the stakeholders especially the community who are also the users and whose major role is paying for the service to enhance sustainability. In this study the Small Scale Water Providers (SSWP) users were found to be satisfied with the service provided than the utility users who felt that more needed to be done. The two providers are found to have different strengths which when combined would enhance service provision. The collaboration between utility with its competence in water supply, technical installations, water quality testing and SSWP with theirs in community involvement, cost recovery, effective operation and maintenance and demand driven water schemes have to be merged to achieve the intended goal and it is also an indication that the two can complement each other. Utility should therefore consider opening investment accounts for all the areas so as to detach PUAs needs from the general plan and eventually budget as they would be self sustaining and enhance  illingness to pay for the users. The SSWP should therefore be viewed as partners by all and licensing should be considered by the government for the benefit of the urban poor.</p>
246

Expanding Water Service Delivery through Partnership between Water Utility and Small Scale Water Providers in Lusaka, Zambia : A Case of Lusaka’s Peri-Urban Areas

Mwandu Siyeni, Yvonne January 2008 (has links)
<p>Zambia is a highly urbanized country with 60% of its urban population residing in low cost areas also called peri-urban, slum or informal settlements. The increase in urban population attributed to rapid migration and urbanization due to political and economic changes has taken a toll on service provision as the infrastructure development and service provision has failed to meet the demand. For the 33 peri-urban areas in Lusaka, the water supply and sanitation has been poor, inadequate and unreliable with the coverage being slightly above 50% for water while 90% of the urban population does not have access to the much needed sanitation. The low coverage is a result of lack the financial capacity on the part of the service providers to extend services to un served areas.</p><p>This research focuses on the strategies to provide sustainable water and sanitation services to peri-urban areas to ensure improved accessibility through the expansion of infrastructure and attainment of full cost recovery. In this era of increasing migration to unplanned settlements where the services are inadequate, alternatives to public provision of water and sanitation services need to be put in place. One of the alternatives is the public-private partnership which encompasses the society, private and the civil society. As has been found in the study the best alternative should not only be completely bottom up but should also be more demand driven and be able to provide for greater contributions from the affected communities.</p><p>The hypothesis of the study is to ascertain if provision of water supply to the Peri-Urban Areas (PUAs) can be achieved through the partnership between the water utility and the small scale water providers. Therefore, the objectives of the research are to: evaluate and compare the current service provision to the peri-urban areas by the utility and small scale providers in terms of technical, social and institutional arrangements and determine the best way of ensuring sustained service provision to peri urban areas and show how partnership can be the best solution to improving service delivery to these areas.</p><p>Service provision in PUAs can not be achieved without the involvement of all the stakeholders especially the community who are also the users and whose major role is paying for the service to enhance sustainability. In this study the Small Scale Water Providers (SSWP) users were found to be satisfied with the service provided than the utility users who felt that more needed to be done. The two providers are found to have different strengths which when combined would enhance service provision. The collaboration between utility with its competence in water supply, technical installations, water quality testing and SSWP with theirs in community involvement, cost recovery, effective operation and maintenance and demand driven water schemes have to be merged to achieve the intended goal and it is also an indication that the two can complement each other. Utility should therefore consider opening investment accounts for all the areas so as to detach PUAs needs from the general plan and eventually budget as they would be self sustaining and enhance willingness to pay for the users. The SSWP should therefore be viewed as partners by all and licensing should be considered by the government for the benefit of the urban poor.</p>
247

Gastro-intestinal nematodes in Ontario sheep flocks - An epidemiological study of over-wintering and anthelmintic resistance

Falzon, Laura Cristina 02 January 2013 (has links)
This thesis was conducted to evaluate important epidemiological features of Gastro-Intestinal Nematode (GIN) infections in Ontario sheep flocks; namely, the PeriParturient Egg Rise (PPER), overwintering of GIN free-living stages on pasture, and Anthelmintic Resistance (AR). Three main studies were carried out: a longitudinal study was conducted on six sheep farms to evaluate the PPER in ewes lambing in different seasons and to determine whether total plasma protein (TPP) levels and packed cell volume (PCV) were associated with increased fecal GIN-egg shedding. Secondly, a pilot-study was conducted on three farms to describe pasture-level environmental conditions and over-wintering survival and infectivity of free-living GIN larvae, especially Haemonchus contortus. Lastly, a cross-sectional study was conducted on 47 sheep farms in Ontario, to evaluate the frequency of AR, compare different diagnostic tests for AR, and evaluate management practices associated with AR. In the longitudinal study, the PPER was observed in winter, spring and autumn lambing ewes, though the magnitude and distribution of the PPER varied with season. Lower TPP and PCV values were associated with increased fecal GIN-egg counts. The pilot-study suggested that H. contortus larvae did not overwinter successfully on pasture, while other GINs, such as Teladorsagia sp., Trichostrongylus spp. and Nematodirus spp., were able to overwinter on pasture, and were infective the following spring. Resistance to ivermectin, fenbendazole and levamisole was demonstrated on 97% (28/29), 95% (19/20) and 6% (1/17) respectively of the farms tested; most of the resistance observed was found in Haemonchus sp. The Fecal Egg Count Reduction percentage following treatment was influenced by which mean (i.e. arithmetic vs. geometric) was used in the formula; use of pre-treatment in addition to post-treatment faecal egg counts was not influential. Both the fecal egg count reduction test and the larval development assay diagnosed resistance, but there was poor agreement between the two tests, as indicated by the Kappa test. The prior use of benzimidazoles on farms was associated with higher levels of fenbendazole resistance. The information generated in this thesis will be used to develop a parasite control program for sheep flocks in Ontario and to guide future research on GIN parasitism. / New Directions - Ontario Ministry of Agriculture, Food and Rural Affairs; Ontario Sheep Marketing Agency; Ontario Agriculture Centre Canada; Merial; Animal Health Strategic Initiative - University of Guelph Partnership; Undergraduate Research Assistantship; Gartshore Memorial Sheep Scholarship;
248

Evaluation of a novel transcortical pin-sleeve system in a calf model

Vogel, Susan R. 04 1900 (has links)
Le desserrage des tiges est une complication fréquente des plâtres avec tiges transcorticales (TP) chez les grands animaux, nécessitant souvent leur retrait prématuré avant la guérison des fractures. Les charges excessives centrées sur le cortex à l’interface os-tige proximo-externe et disto-interne causent de l'ostéolyse. En utilisant un modèle de veau nouveau-né, ce projet a évalué un nouveau système de tige-manchon et anneau integré dans un plâtre (PS) optimisé pour réduire la contrainte péri-implant et le stress à l'interface os-implant. On a émis l'hypothèse que les PS se traduiraient par une ostéolyse péri-implant moindre par rapport aux TP. Dix veaux en bonne santé, de 3 semaines d'âge, ont été implantés avec les TP ou PS dans le métacarpe droit, à raison de 2 implants par veau. Les veaux ont été observés quotidiennement pour le confort et la boiterie et ont été euthanasiés à 28 jours. Les données recueillies comprenaient les radiographies à la chirurgie et à l'euthanasie et les mesures histomorphométriques de contact os-implant sur des échantillons non-décalcifiés avec les implants in situ. Les données ont été analysées en utilisant le test de Cochran-Mantel-Haenszel, une valeur de P <0,05 a été considérée comme significative. L'épaisseur corticale était plus importante pour les implants distaux que proximaux pour les deux groupes lors de la chirurgie (P = 0,03), mais était similaire entre les groupes (P > 0,3). Les veaux avec TP ont développé une boiterie plus tôt (au jour 21) que les veaux avec PS (P = 0,04). Histologiquement, il y avait plus de contact direct os-implant cortical pour les implants PS distaux que les implants TP (P = 0,04). La jonction métaphyso-diaphysaire osseuse où les implants proximaux étaient situés est impropre aux deux systèmes; chacun a un minimum de contact os-implant et de l'ostéolyse extensive. Le système PS n'ayant pas causé une ostéolyse importante lorsque implantés dans l'os diaphysaire et peut-être une alternative convenable aux TP pour des fractures comminutives des membres distaux. / Pin loosening is a common complication of transfixation pincasts (TP) in large animals, often necessitating premature removal before fracture healing. The excessive loads centered on the proximo-external and disto-internal cortices of the bone-pin interface cause osteolysis. Using a neonatal calf model, this project evaluated a novel pin-sleeve and ring cast system (PS) optimized to decrease peri-implant strain and evenly share stress at the bone-implant interface. It was hypothesized that PS would result in less peri-implant osteolysis compared to TP. Ten, 3-week-old, healthy calves were implanted with either TP or PS in the right metacarpus, 2 implants per calf. Calves were scored daily for lameness and were euthanized at day 28. Collected data included radiographs at surgery and euthanasia and histomorphometric measures of bone-implant contact on non-decalcified specimens with the implants in situ. Data was analyzed using Cochran-Mantel-Haenszel test; a P-value <.05 was considered significant. The cortical thickness was larger for distal implants than proximal implants for both groups at surgery (P = 0.03), but were similar between groups (P > 0.3). TP calves developed lameness sooner, at day 21, than PS calves (P = 0.04). Histologically, there was more direct cortical bone-implant contact for PS distal implants than TP implants (P = 0.04). The metaphyseal-diaphyseal junction where the proximal implants were situated is unsuitable bone for either system; each had minimal bone-implant contact and extensive osteolysis. The PS system did not cause significant osteolysis when instrumented in diaphyseal bone and is a suitable alternative to TP for comminuted distal limb fractures.
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Jakten på gränsen mellan land och stad : en ANT-studie om att planera det oplanerade

Johnson, Linus January 2018 (has links)
Denna uppsats ämnar belysa hur planeringen av land och stad framstår vara ett till synes stabilt system där vissa förhållanden tas för självklarheter. Vidare är syftet att undersöka hur planeringen hanterar områden som faller utanför kategorierna land och stad. Detta med bakgrund av diskussioner om att ”god” planering i samtiden förespråkar täta städer och utveckling av orter i kollektivtrafikstråk – en tanke som bygger på, och legitimeras av, en dikotomi om å ena sidan ett land och å andra sidan en stad vilka ska hållas separerade. Samtidigt erkänns det komplexa och intrikata förhållande som kategorierna har till varandra. Uppsatsen ställer sig således frågorna hur denna dikotomi om land och stad produceras i planeringen, samt hur den kommer till användning. Studien grundar sig på ett perspektiv om världens beskaffenhet så som aktör-nätverksteorin (ANT) förordar. ANT ser världen som ständiga processer och ett ständigt görande i en värld bestående av både människor och ickemänniskor, aktörer, som alla kan spela roll. Studien får låta uppvisa hur förhållandet mellan aktörer ter sig, och hur en dikotomi produceras och byggs upp. För studien har Linköping kommuns initierade arbete med en ny ytterstadsplan, ett tillägg till deras Översiktsplan för staden Linköping, varit föremål där dokument, miljöer och workshopar i det tidiga samrådsskedet observerats. Ytterstaden befinner sig på gränsen mellan Linköpings innerstad och dess landsbygd. När denna nu är föremål för ett planarbete har vedertagna sanningar om land och stad öppnats upp för diskussion. Detta kan bidra till förståelse för hur planeringen konstruerar och bygger upp kategorierna land och stad och vidare använder dessa som aktörer för att värva ytterstaden till de befintliga planeringsstrukturerna – att planera det som antingen landsbygd eller stad, inte något som faller där emellan. För att planeringen ska uppträda som ett stabilt system visar det sig att denna behöver alliera sig med ytterligare aktörer för att driva igenom sina agendor. Planeringen är inte i sig en stark kraft utan tillsammans med ytterligare aktörer, som kategorierna land och stad, gränser, tidningsartiklar och översiktsplaner skapas det vi betraktar som ett stabilt system – och vidare till vilken planeringen söker värva nya aktörer, som ytterstaden, för att passa in. Dikotomin mellan land och stad konstrueras i planeringen genom att värva vissa aktörer och etablera dessa i positioner som håller över tid och rum – i översiktsplanekartor och i dokument. På så sätt etableras nya aktörer med vilken förmågan kommer att motivera och legitimera utvecklingsområden som något som faller inom på förhand etablerade kategorier. Uppträder planeringsföremål utanför kategorierna passar planeringen in dem i de redan existerande.
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Conflits, usages et représentations des processus de patrimonialisation des quartiers anciens péricentraux : étude comparée de Bâle, Strasbourg et Valparaiso / Conflicts, practices and representations of the patrimonialization process in the old peri-central neighbourhoods : comparative research in Basel, Strasbourg and Valparaiso

Soto, Maximiliano 02 November 2012 (has links)
Cette thèse compare les processus de patrimonialisation dans des quartiers péricentraux de trois villes reconnues pour la qualité de leur patrimoine bâti et culturel : Bâle, Strasbourg et Valparaiso. En partant des paradigmes de la transaction sociale et de la régulation conjointe, la patrimonialisation est abordée comme un processus dynamique qui produit des conflits, des enjeux et des négociations dans un jeu d’acteurs multipolaire. Cette relation conflictuelle structure des coopérations entre trois niveaux d’expertises : officielle, savante et profane. Ces jeux d’acteurs donnent naissance à la communauté patrimoniale lorsque le rapport des forces entre la matérialité et l’immatérialité des biens patrimoniaux déclenche des conflits. La méthodologie comparative combine une analyse ethnographique qui est accompagnée d’entretiens avec des personnes-ressources, des questionnaires aux résidants et des données sociographiques quantitatives. / This PhD dissertation compares the patrimonialization process in the peri-central neighbourhoods of three heritage cities: Basel, Strasbourg and Valparaiso. Built on two paradigms, the social transaction and the joint regulation, patrimonialization is a dynamic process which produces conflicts, stakes and negotiations in a multipolar actors involvement. This conflicting relationship structures co-operations between three levels of expertises: official, scholar and popular. These actors’ interactions give birth to a patrimonial community whilst the force relationship between the materiality and the immateriality of the patrimonial properties trigger conflicts. The comparative methodology combines an ethnographical analysis including interviews with key resource persons, questionnaires among residents and socio-graphic quantitative data.

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