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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.
811

Effects of nutrient-tannin interactions on intake and germination of woody plant species by ruminants

Monegi, Piet 07 1900 (has links)
Woody plant encroachment is one of the major problems worldwide because it affects negatively the herbaceous layer, which provide forage for livestock production. However, the role of ruminants particularly browsers in the dispersal of woody plant seeds still remains a concern for farmers interested in grass production. Seedpods of various woody plant species constitute a crucial part of the diet of herbivores during the dry season because of their high nutritional quality compared to herbaceous material. The interaction of associated diet quality, seed characteristics and animal species among other factors play a pivotal part in the success of livestock faecal seeds dispersion. Furthermore, dispersed seeds that successfully grow into mature woody plants become an important source of protein for herbivores. The use of woody plants as a source forage is known to be limited by plant secondary metabolites (PSMs) such as condensed tannins. The objectives of this study were to determine 1) the effects of condensed tannins and crude protein of Vachellia tortilis and Dichrostachys cinerea pods in seed recovery and germination fed to goats, and 2) the effects of diet mixing on the feed intake of plant species by goats. In the first experiment, a total of 12 female indigenous goats and 12 female Pedi sheep were utilised in this study, with the average body weights of 29.50 kg ± 1.60 (S.E) and 28.70 kg ± 1.60, respectively. Twelve goats were grouped into two groups of six goats per group, one group was fed D. cinerea pods and the other group was fed V. tortilis pods. The group of 12 sheep were divided similarly, the one group was fed D. cinerea pods and the other group was fed V. tortilis pods. Each animal was given V. tortilis and D. cinerea pods at 2.50% of their body weight. All animals were allowed to consume D. cinerea or V. tortilis pods within 24 h, after which the remaining pods were collected and weighed. Faecal collection commenced immediately after the 24 h pods feeding and was carried on until no seeds were discovered in faeces. All faeces extracted from sheep and goats were collected daily in the morning from the faecal bags. In the second experiment, a total of 24 indigenous goats with average body weight of 26.6 kg ± 0.51 were utilised. Goats were arbitrarily selected and grouped into four groups of six goats per group (goats were placed individually in 2 m2 pens). Each group was fed one of the following diets: diet one - Searsia lancea, diet two - S. pyroides, diet three - Euclea crispa and diet four - was a combination of the three plant species (Searsia lancea, S. pyroides and Euclea crispa). Searsia lancea, S. pyroides and E. crispa branches were collected every morning prior to feeding, and were weighed before offering the animals. Refusals were gathered and weighed, and intake was calculated as distinction between weight in and refusals. Plant species foliage were analysed for crude protein, condensed tannin, acid detergent lignin, acid detergent fibre and neutral detergent fibre. During the first experiment, the cumulative percentage seed recovery of V. tortilis from goats (46.00 % ± 1.90) and sheep (52.00 % ± 2.93) was significantly higher than D. cinerea from goats (13 % ± 1.47) and sheep (24.00 % ± 1.16). Germination percentage of D. cinerea seeds that passed through the gastro-intestinal tract of goats (33.12 % ± 2.94) and sheep (36.00 % ± 2.68) was significantly higher than V. tortilis seeds that passed through the gastro-intestinal tract of goats (28.98 % ± 2.68) and sheep (23.04 % ± 2.81). Average D. cinerea (34.56 % ± 1.99) and V. tortilis (26.02 %± 2.10) seeds that went through the gastro-intestinal of goats and sheep had a significantly higher germination rate than the control (i.e. no passage through the gut; D. cinerea = 2.31 % ± 1.55, V. tortilis = 5.07 % ± 2.68). The high mean cumulative percentage seed recovery of V. tortilis (18.80 %) may be attributed to the relatively higher crude protein than D. cinerea (12.20 %). This may encourage animal seed dispersal and germination of woody plant species with relatively high crude protein content. In the second experiment, Searsia lancea contained 8.50 % CP, 21.46 % acid detergent fibre (ADF), 12.50 % ADL and 39.37 % NDF. Searsia pyroides had 9.03 % CP, 27.07 % ADF, 10.89 % ADL and 40.30 % NDF. Euclea crispa had 6.19 % CP, 26.20 % ADF, 16.63 % ADL and 30.02 % NDF. Mixed diet (combination of the three plant species) had 8.96 % CP, 23.72 % ADF, 11.13 % ADL and 38.28 % NDF. Searsia lancea had 2.70 % of CTs while S. pyroides had 5.20 % CT, E. crispa had 6.44 % CT and mixed diet had 7.20 % CT. The mean dry matter intake varied significantly among dietary groups (P < 0.001). Similarly, goats offered a mixed diet consumed more CTs (P < 0.01) than those offered individual forage species. The high mean cumulative percentage seed recovery of V. tortilis may be attributed to the higher crude protein of V. tortilis (18.80 %) than D. cinerea (12.20 %). Higher passage rate may encourage animal seed dispersal and germination of plant species. The results from experiment two support the postulation that animals foraging in mixed diet systems consume more PSMs and achieve higher dry matter intake than animals confined to monocultures or single species feeding systems. Given that woody plant encroachment is already reducing farm-grazing capacities in African savannas and this problem is predicted to double by 2050, strategies that improve herbivore ability to consume woody plants will increase forage availability and inform bush control programmes and policies. Moreover, the concomitant increase in CTs by goats exposed to diets with diverse species also has positive implications for animal / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
812

An explorative study on the development of a framework for the measurement of performance and trust

Durand, Lenard 06 1900 (has links)
Based on literature, a theoretical model was developed for viable performance consisting of eight constructs whilst the trust model of Martins (2000) was used to measure four organisational trust constructs. Exploratory factor analysis was used to extract the constructs, and structural equation modelling was employed to validate the models against the data. An empirical model for viable performance resulted in a solution with seven constructs and organisational trust with five constructs. The two empirical models were unified into a model of viable performance and trust resulting in a measurement model where all 12 constructs were shown. Significant levels of internal consistency were measured. The resulting measurement model was tested for group differences, and no significant differences were found, indicating that the assessment can be used across different groups. It was concluded that the aim to construct and test an integrated and comprehensive theoretical framework of viable performance and trust was achieved and the resulting Viable Performances and Trust Indicator (VPTI) was validated as an assessment to be used across groups. Organisations can thus use the framework and VPTI assessment tool with confidence to assess performance and trust across different biographical groups. Future researchers can build on this exploratory study to refine the scales and apply the measurement model within the wider context of South Africa or as a globally accepted model. / IndustriaI and Organisational Psychology / D. Litt. et Phil. (IndustriaI and Organisational Psychology)
813

A decision model for contracting out local government services in a South African context

Slot, Paul Johan 06 1900 (has links)
Business management / M. Com. (Business management)
814

Antioxidative, analgesic and anti-inflammatory activities of Acokanthera oppositifolia, Plantago lanceolata, Conyza canadensis, and Artemisia vulgaris

Ondua, Moise 02 1900 (has links)
The anti-inflammatory properties of four medicinal plants were investigated. These plant extracts were subjected to screening for their possible effects as antioxidative, analgesic, and anti-inflammatory agents. In the antioxidant activity, the Plantago lancelota extracts resulted in an IC50 value of 0.4 mg/mL compared to the positive control quecertin with IC50 0.04 mg/mL Plantago lanceolata inhibited COX-2 activity with IC50 values of 0.41 mg/mL. However, the COX-1 inhibition indicated an IC50 of 68.99 mg/mL. The lipoxygenase assay indicated that Plantago lanceolata was the most active plant species with an IC50 value of 4.86 mg/mL compared to the positive control (quecertin) with an IC50<2mg/mL. The nitric oxide assay of the plant extracts indicates a dose-dependent activity of our plant extracts. Likewise the cell viability result indicated a good activity at dose 100 mg/mL. / Life and Consumer Sciences / M. Sc. (Life Sciences)
815

Perturbation de la production de la parole suite à une opération de la glande thyroïde / Perturbation of speech production as a result of thyroid gland surgery

Fauth, Camille 04 December 2012 (has links)
L’objectif de ce travail, mené en partenariat avec le Département de Chirurgie Oncologique du Centre Paul Strauss à Strasbourg, est d’évaluer les conséquences d’une chirurgie thyroïdienne sur la voix des patients, afin de déceler les différentes perturbations qu’entraîne cette opération chirurgicale, et de mettre au jour les possibles stratégies de compensation ou de réajustements que le patient peut mettre en place, seul ou à l’aide d’une rééducation orthophonique ; il s’agit d’une étude longitudinale. L’évaluation reposait sur l’analyse de signaux acoustiques, à partir desquels une quantité importante d’indices relatifs à la qualité vocale, mais aussi aux comportements articulatoires des locuteurs, a pu être extraite. La production de voyelles soutenues a permis de conduire deux études spectrales. L’étude spatio-temporelle a été rendue possible grâce à l’analyse de logatomes, et plus précisément de séquences VCV. Nous avons mené trois expériences sur le plan acoustique. La première expérience traite des caractéristiques spectrales de la voix de patients ayant subi une thyroïdectomie et ne présentant pas d’immobilité laryngée. La deuxième étude est menée à partir des caractéristiques spectrales de la voix de locuteurs présentant une immobilité laryngée post-thyroïdectomie. Enfin, notre dernière expérience a pour objet, l’étude des caractéristiques spatio-temporelles de la voix de locuteurs qui ont subi une thyroïdectomie et présentant une immobilité laryngée. L’interprétation articulatoire, effectuée à partir des données acoustiques, révèle des perturbations aussi bien des gestes glottiques que des gestes supraglottiques, avec des stratégies de réajustements variables suivant les patients. La conception d’une « cible », comme espace de contrôle pour la réalisation de possibles articulatoires et acoustiques perceptivement acceptables, semble particulièrement pertinente ici, dans la mesure où les locuteurs pathologiques réorganisent leurs productions selon leurs propres contraintes physiologiques et anatomiques, provoquées par leur pathologie. / The aim of this study, conducted in partnership with the Department of Surgical Oncology, Centre Paul Strauss in Strasbourg, is to assess the consequences of thyroid surgery on the voice of patients, in order to identify the various perturbations caused by this surgery, and also to reveal possible compensatory strategies or readjustments that the patient may develop, alone or with speech therapy; this is a longitudinal study. The assessment was based on the analysis of acoustic signals, from which a large amount of cues related to voice quality, but also to articulatory behaviour of speakers was extracted. Production of sustained vowels allowed carrying out two spectral studies. The spatiotemporal study was made possible through the analysis of nonsense words, and more specifically through VCV sequences. We conducted three experiments on the acoustic level. The first experiment deals with the spectral characteristics of the voice of patients who underwent thyroidectomy, with no laryngeal paralysis. The second study was conducted based on spectral characteristics of the voice of speakers with laryngeal post-thyroidectomy paralysis. Our final experiment was to study spatio-temporal characteristics of the voice of speakers who underwent thyroidectomy, with laryngeal paralysis. Articulatory interpretations, made from the acoustic data, reveal perturbations of gestures on both the glottal and supraglottal levels, with readjustment strategies varying according to patients. The concept of a "target" as a control space for execution of possible articulatory and acoustic entities, which are perceptually acceptable, seems particularly relevant in this study, since disordered speakers reorganize their productions according to their own physiological and anatomical constraints, caused by the disorder.
816

Efeitos biológicos e avaliação dose-resposta das partículas de exaustão do diesel sobre o desenvolvimento embrionário inicial de camundongos / Biological effects and dose-response assessment of diesel exhaust particles on in vitro early embryo development in mice

Daniela Aparecida Nicolosi Foltran Januário 12 March 2010 (has links)
Experimentos anteriores realizados em nosso laboratório indicam que o sucesso gestacional é afetado pela poluição atmosférica. O presente estudo teve como objetivo avaliar os efeitos biológicos associados a uma curva dose resposta das partículas de exaustão do diesel (PED) sobre o desenvolvimento embrionário inicial e o potencial de implantação, utilizando-se como modelo a fertilização in vitro e o cultivo embrionário de camundongos. No Experimento 1, encontrou-se um efeito negativo dose-dependente sobre o desenvolvimento embrionário inicial, o processo de eclosão, a alocação das células e a morfologia da massa celular interna (MCI) dos blastocistos. A análise post-hoc revelou que o desenvolvimento precoce do embrião não foi afetado pelas concentrações de 0,2 µg/cm2 ou 2 µg/cm2, mas foi significativamente afetado pela concentração de 20 µg/cm2 de PED. O processo de eclosão foi prejudicado pelas concentrações de 2 µg/cm2 e 20 µg/cm2. A alocação das células da MCI e a relação entre as células da MCI e do trofectoderma foram significativamente afetadas por todas as concentrações. Adicionalmente, observou-se um efeito negativo sobre a morfologia da MCI para as concentrações de 2 µg/cm2 e 20 µg/cm2. O Experimento 2, apesar de não mostrar efeito significativo sobre o potencial de implantação, evidenciado pela capacidade de adesão dos blastocistos e crescimento trofoblástico, revelou que a morfologia da MCI no dia 8 de cultivo, as taxas de viabilidade e de apoptose celular e a expressão de Oct4 e Cdx2 foram significativamente afetadas. O teste HSD-Tukey demonstrou que a presença de PED (0,2 µg/cm2 e 2 µg/cm2) durante o desenvolvimento embrionário aumentou significativamente a taxa de células em apoptose dos embriões tanto no dia 5 quanto no dia 8 de cultivo e, embora a proporção de células viáveis no dia 8 tenha sido prejudicada por ambas as concentrações, apenas a exposição a 2 µg/cm2 de PED diminuiu a viabilidade celular no dia 5. Por outro lado, tanto a concentração de 0,2 µg/cm2 como a de 2 µg/cm2 tiveram um efeito negativo significativo sobre a qualidade da MCI no dia 8 e a taxa de expressão de Oct4 nos blastocistos e aumentaram a porcentagem de células desses blastocistos expressando Cdx2, adicionalmente, a razão Oct4/Cdx2 dos embriões expostos a 0,2 µg/cm2 e 2 µg/cm2 foi significativamente menor. Frente a esses resultados, presumi-se que as PED poderiam estar envolvidas nos mecanismos que levariam à diminuição do sucesso reprodutivo observado em camundongos expostos à poluição atmosférica ambiental / Previous experiments conducted in our laboratory demonstrate that successful pregnancy is affected by air pollution. The aim of this study was to evaluate the biological effects associated with a dose-response curve of the diesel exhaust particles (DEP) on early embryonic development and implantation potential, using mice in vitro fertilization and culture embryo as model. In Experiment 1, we found a negative dose-dependent effect on the embryonic development, hatching process, cell allocation and morphology of inner cell mass (ICM) of blastocysts. A post-hoc analysis revealed that the early development of the embryo was not affected by concentrations of 0.2 g/cm2 or 2g/cm2, but was significantly affected by the concentration of 20 g/cm2 of DEP. The hatching process was impaired by concentrations of 2 g/cm2 and 20 g/cm2. Cell allocation of ICM and the ratio between cells of ICM and trophectoderm were significantly affected by all concentrations. Addicionaly, we observed a negative effect on ICM morphology was observed for the 2 µg/cm2 and the 20 µg/cm2 concentrations. Experiment 2, despite showing no significant effect on implantation potential, as evidenced by the adhesion ability and trophoblast outgrowth, revealed that ICM morphology on day 8 of culture, rates of cell viability and apoptosis, and expression of Oct4 and Cdx2 were significantly affected. The Tukey HSD test showed that presence of DEP (0.2 g/cm2 and 2 g/cm2) during embryonic development increased significantly the rate of apoptotic cells in embryos as on day 5 as on day 8 of culture, although the proportion of viable cells on day 8 was impaired by both concentrations, only exposure to 2 g/cm2 PED decreased cell viability on day 5. On the other hand, both the concentration of 0.2 g/cm2 such as 2 g/cm2 had a significant negative effect on the quality of ICM on the day 8 and the rate of expression of Oct4 on blastocysts, and increased the percentage of cells from these embryos expressing Cdx2, also, Oct4/Cdx2 ratio were significantly lower in the blastocysts derived from embryos exposed to 0.2 g/cm2 and 2 g/cm2¬ concentrations. Given these results, the suggestion is that DEP could be involved in the mechanisms that lead to decreased reproductive success observed in mice exposed to environmental pollution
817

Qualidade fisiológica e sanitária das sementes de cultivares crioulas de feijão produzidas no sistema orgânico e convencional / Physiological and sanitary quality of seeds of landraces of beans produced in organic and conventional system

Gindri, Diego Medeiros 28 February 2014 (has links)
Made available in DSpace on 2016-12-08T16:44:46Z (GMT). No. of bitstreams: 1 PGPV14MA138.pdf: 1499823 bytes, checksum: 43bb00530c794a8a0bd7e5e0266cd64d (MD5) Previous issue date: 2014-02-28 / The sustainability of agricultural systems has been a collective effort of farmers, technical assistants and researchers, where the maintenance of agrobiodiversity is essential for food production in a sustainable manner. Knowledge of the potential characteristics of seeds landraces on condition of organic and conventional crops can assist in recovery, by farmers, the habit of conserving seeds and increase the use of these genetic resources by farmers, also increasing the possibility of management and conservation agrobiodiversity. The objective of this study was to characterize the physiological quality (viability and vigor), health quality (incidence of Colletotrichum lindemuthianum) and storability (tolerance to deterioration) of seeds of bean genotypes grown in two agricultural crops under organic and conventional cultivation, in order to obtain information on the genetic response of each cultivar to different production systems and the potential of each genotype as attributes of physiological and sanitary quality of seeds. The seeds were grown in field crops in 2011/2012 and 2012/2013, in Campos Novos / SC. Twenty-six genotypes (Table 1) were used, originating from the collection of Active Bank of bean germplasm (BAF) of Agroveterinárias Sciences Center of the State University of Santa Catarina - CAV / UDESC. The analyzes were performed on Seeds Analysis Laboratory (LAS), the CAV / UDESC, soon after harvest and after storage of seeds in the laboratory, between the months of March to October, with temperature and relative humidity of the ambient air. Was held germination tests, emergency field, electrical conductivity, accelerated aging, cold, measuring the lengths of seedlings and sanity. The genetic diversity found in the results and ranking the sum of posts Mulamba and Mock associated with the grouping method of Scott-Knott, allowed categorizing genotypes for physiological quality and storability of seeds. The landraces BAF 75, 55, 81, 84, 60, 13, 36, 42 and the commercial cultivars BAF 110 and 121 were identified with high potential physiological quality in seeds produced, and indicated for seed production both in conditions organic and conventional farming. The landraces BAF 84, 81, 75, 55, 36 and 42 were identified with high physiological potential of seed storage in the conditions of temperature and humidity uncontrolled, being able to maintain the viability and vigor of seeds for a period of eight months after harvesting, what allows the use of seed for the next crop. The landraces BAF 42 and 75 presented high seed quality in both agricultural system in the two years of cultivation, maintained after storage and with a low infection of C. lindemuthianum / A sustentabilidade dos sistemas agrícolas tem sido um esforço coletivo de agricultores, assistentes técnicos e pesquisadores, onde a manutenção da agrobiodiversidade é indispensável para a produção de alimentos de forma sustentável. O conhecimento das características potenciais das sementes dos genótipos crioulos sob condição de cultivo orgânico e convencional pode auxiliar na retomada, por parte dos agricultores, do hábito de conservação de suas sementes e potencializar o uso destes recursos genéticos pelo agricultor, ampliando também a possibilidade de manejo e a conservação da agrobiodiversidade. O objetivo do trabalho foi caracterizar a qualidade fisiológica (viabilidade e o vigor), qualidade sanitária (incidência de Colletotrichum lindemuthianum) e o potencial de armazenamento (tolerância a deterioração) das sementes de genótipos crioulos e comerciais de feijão produzidas em duas safras agrícolas sob cultivo orgânico e convencional, com o intuito de obter informações sobre a resposta genética de cada cultivar aos diferentes sistemas de produção e as potencialidades de cada genótipo quanto aos atributos de qualidade fisiológica e sanitária das sementes. As sementes foram produzidas em campo, nas safras 2011/2012 e 2012/2013, em Campos Novos/SC. Foram utilizados vinte e seis genótipos de feijão (Tabela 1), com origem da coleção do Banco Ativo de germoplasma de feijão (BAF) do Centro de Ciências Agroveterinárias da Universidade do Estado de Santa Catarina CAV/UDESC. As análises das sementes foram realizadas no Laboratório de Análise de Sementes (LAS), do CAV/UDESC, logo após a colheita e após o armazenamento das sementes no laboratório, entre os meses de março a outubro, com temperatura e umidade relativa do ar ambiente. Realizou-se os testes de germinação, emergência a campo, condutividade elétrica, envelhecimento acelerado, frio, medição dos comprimentos de plântulas e sanidade. A diversidade genética encontrada nos resultados e a classificação na soma de postos de Mulamba e Mock associada ao método de agrupamento de Scott-Knott, permitiu categorizar os genótipos quanto à qualidade fisiológicas e o potencial de armazenamento das sementes. As cultivares crioulas BAF 75, 55, 81, 84, 60, 13, 36, 42 e as cultivares comerciais BAF 110 e 121 foram identificadas com alto potencial de qualidade fisiológica nas sementes produzidas, e indicadas para a produção de sementes, tanto nas condições de cultivo orgânico como convencional. As cultivares crioulas BAF 84, 81, 75, 55, 36 e 42 foram identificadas com alto potencial fisiológico de armazenamento das sementes nas condições de temperatura e umidade ambiente, sendo capazes de manter a viabilidade e o vigor das sementes por um período de oito meses após a colheita, o que permite o uso das semente para a safra seguinte. As cultivares crioulas BAF 42 e 75 apresentaram alta qualidade das sementes produzidas em ambos os sistema agrícolas nos dois anos de cultivo, mantida após o armazenamento e com baixa infecção de C. lindemuthianum
818

Gest?o da cadeia de fornecimento :um estudo em empresas de constru??o certificadas com a ISO 9000 / Supply chain management: a study in brazilian construction companies with ISO 9000 certification

Albuquerque, Adalberto Aguiar 19 May 2006 (has links)
Made available in DSpace on 2014-12-17T14:52:50Z (GMT). No. of bitstreams: 1 AdalbertoAA.pdf: 1733034 bytes, checksum: c39f7c59557751fe039012b53650abfc (MD5) Previous issue date: 2006-05-19 / The aim of this present research is to investigate about aplication of the supply chain management in Civil Construction, through perception of brasilian building companies directors. Research purpose includes potential benefits and main dificults analysis in supply chain management, beyond to identify decision criterions for suppliers and sales chain (commission agent and real state agency) choice and reduction, to facilility management in companies. The methodology used in this work considers the application of a questionnaire with scales of the type Likert being constituted of variables that compose the aspects of evaluation and of behaviors, beyond questions to identify the market profile of the respondents. For analysis statistics is used the descriptive, clusters and variance, ANOVA, analysis last two to verify the connections between variables. The results show more perception as for long terms contracts with suppliers for purchase of materials and services being decisive for companies nowadays (40%) than as for exclusive contracts with commission agents (30%). There is a positive appraisal about viability of hipotetic situations showed, but more caution as for disposition to apply them too. Another results aim for biggers dificults in management of chain links formed by commission agents and real state agencies, than chain links formed by anothers suppliers of materials and services. The companies for study were chosen among to those with ISO 9000 certificate until november 2001, considering that these companies have the best management systems, probably / O objetivo desta pesquisa ? investigar a aplica??o da gest?o da cadeia de fornecimento na Constru??o Civil atrav?s da percep??o de dirigentes das empresas construtoras brasileiras. O escopo da pesquisa inclui a an?lise dos benef?cios potenciais e principais dificuldades na gest?o da cadeia de fornecimento, al?m de identificar os principais crit?rios de decis?o na escolha e redu??o de fornecedores e canais de venda (corretores e imobili?rias), fato que facilitaria a gest?o da cadeia como um todo. A metodologia utilizada no trabalho considera a aplica??o de um question?rio com escalas do tipo Likert constitu?do de vari?veis com aspectos avaliativos e atitudinais, al?m de perguntas para identificar o perfil de mercado das respondentes. Foi empregada na an?lise estat?stica a an?lise descritiva, de Agrupamentos (Clusters) e de vari?ncia, ANOVA, as duas ?ltimas para identificar poss?veis rela??es entre as vari?veis pesquisadas. Os resultados mostram a maior percep??o quanto ao estabelecimento de contratos de longo prazo com fornecedores para a compra de materiais e servi?os j? ser decisivo para as empresas (40%), do que os contratos de exclusividade com corretores (30%). Existe tamb?m uma avalia??o positiva da viabilidade dos cen?rios apresentados, mas uma maior cautela quanto ? disposi??o de implant?-los nas empresas. Outros resultados apontam para maiores dificuldades na gest?o de elos da cadeia formados por corretores e imobili?rias que os formados pelos outros fornecedores de materiais e servi?os. Foram escolhidas para a pesquisa as empresas brasileiras com certifica??o ISO 9000 at? novembro de 2001, considerando que estas s?o as mais prov?veis de possuir um sistema de gest?o mais avan?ado
819

Avaliação in vitro da viabilidade de Enterococcus faecalis e Candida albicans nos túbulos dentinários após a aplicação de hidróxido de cálcio e clorexidina gel 2% / In vitro evauluation of the viability of Enterococcus faecalis and Candida albicans in dentinal tubules after placement of calcium hydroxide and chlorhexidine gel 2%

Ronan Jacques Rezende Delgado 12 June 2007 (has links)
Uma infecção pulpar pode resultar na colonização microbiana de todo sistema de canais radiculares incluindo os túbulos dentinários. Estes microorganismos e seus produtos tóxicos são responsáveis pelo desenvolvimento e persistência da periodontite apical de origem endodôntica. O presente estudo objetivou avaliar a viabilidade de E. faecalis e C. albicans em túbulos dentinários após a aplicação de hidróxido de cálcio, clorexidina gel 2%, hidróxido de cálcio associado à clorexidina gel 2% e soro fisiológico, através da análise por cultura microbiológica e microscopia de fluorescência. Para tanto 120 raízes de dentes humanos foram padronizadas e autoclavadas, sendo posteriormente divididas em 2 grupos (n= 60) para contaminação com E. faecalis e C. albicans por 21 dias. Em seguida, foram divididas em 8 grupos (n= 15) para aplicação das substâncias antimicrobianas nos canais radiculares e posterior incubação em estufa por 14 dias. Amostras da dentina radicular na extensão de 0 - 100 µm e de 100 - 200 µm foram coletadas e submetidas à cultura microbiológica através do plaqueamento em meios de cultura. Após 48 horas de incubação promoveu-se a avaliação das UFC. Paralelamente, as amostras foram processadas para análise em microscopia de fluorescência com auxílio de marcadores fluorescentes específicos, a fim de se determinar a proporção de microorganismos viáveis e não viáveis. Outros 6 espécimes foram preparados para análise em MEV. Os resultados mostraram uma maior capacidade de penetração intratubular para E. faecalis quando comparado a C. albicans. A aplicação de medicação intracanal resultou em significativa redução da viabilidade dos microorganismos quando comparado ao grupo controle independente da medicação aplicada e em ambas as porções da dentina radicular avaliadas. Entretanto, ao compararmos individualmente as medicações, observamos o melhor desempenho da clorexidina gel 2 % e da associação de hidróxido de cálcio e clorexidina gel 2% sem diferença significante entre elas. O hidróxido de cálcio apresentou os piores resultados para desinfecção dos canais radiculares contaminados com E. faecalis e C. albicans. Estes achados foram confirmados tanto pela cultura microbiológica quanto pela microscopia de fluorescência. A cultura microbiológica e a microscopia de fluorescência são métodos adequados e complementares para avaliação da viabilidade de E. faecalis e C. albicans e a eficácia da clorexidina gel 2% e da associação hidróxido de cálcio e clorexidina gel 2% justificam seu uso em endodontia como medicação intracanal. / A pulp infection can result in a microbial colonization of the entire root canals system, including dentinal tubules. These microorganisms and their toxic product are responsible for the development and persistence of apical periondontitis from endodontic source. The present study aimed to evaluate E. faecalis and C. albicans viability in dentinal tubules after the application of calcium hydroxide, chlorhexidine gel 2%, calcium hydroxide associated to chlorhexidine gel 2% and physiological solution, through the analysis by microbiological culture and fluorescence microscopy. For that, 120 human teeth root were standardized and submitted to autoclave, and after ere divided into 2 groups (n=60) for E. faecalis and C. albicans contamination for 21 days. Following this, they were divided into 8 groups (n=15) for application of antimicrobial substances in the root canals and subsequent incubation for 14 days. Samples from root dentin with 0 - 100 µm and 100 - 200 µm of extension were collected and submitted to microbiological culture.After 48 hours of incubation, it was performed the evaluation of colony-forming units (CFU). At the same time, the samples were processed for fluorescence microscopic analysis with the assistance of specific fluorescent markers, in order to determine the proportion of viable and non-viable microorganisms. Other 6 specimens were prepared for the analysis of scanning electron microscopy. Results demonstrated a higher capacity of penetration in the tubules for E. faecalis than for C. albicans. The application of intracanal medication resulted in significant reduction of microorganisms viability when compared to the control groups independently of the medication used and in both evaluated portions of root dentin. However, when one compares individually the medications, it was observed a better performance of chlorhexidine gel 2% and the association of calcium hydroxide with chlorhexidine gel 2% without a significant difference between them. Calcium hydroxide had the worst results for disinfection of root canal contaminated with E. faecalis and C. albicans. These findings were confirmed for the microbiological culture as well as for the fluorescence microscopy. The microbiological culture and the fluorescence microscopy are adequate methods and complementary for the evaluation of E. faecalis and C. albicans viability and the efficacy of chlorhexidine gel 2% and the association of calcium hydroxide with chlorhexidine gel 2% warrant their use in Endodontics as an intracanal medication.
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Uso racional de energia em fazendas leiteiras com bombas de calor / Rational use of energy in dairy farms with pumps

Baldassin Junior, Ricardo, 1979 02 October 2006 (has links)
Orientador: Luis Augusto Barbosa Cortez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T21:47:29Z (GMT). No. of bitstreams: 1 BaldassinJunior_Ricardo_M.pdf: 12303899 bytes, checksum: eebb86f1faa615631b1652ad9774ddde (MD5) Previous issue date: 2007 / Resumo: O leite é um dos mais importantes produtos da agropecuária nacional, com cerca de 2/3 das propriedades rurais do país destinando-se à pecuária leiteira e com um dos maiores rebanhos do mundo. Apesar da grandiosidade, o setor ainda sofre com a baixa produtividade, os altos custos e a defasagem tecnológica. Como conseqüência, muitos produtores abandonaram suas atividades diante deste novo cenário competitivo. Atualmente, assuntos como uso racional de energia e aplicação intensiva de tecnologia tem sido intensamente discutidos e abordados, e indicados como aspectos importantes para a obtenção de ganhos de produtividade. Desta forma, visou-se neste trabalho avaliar o uso de energia no processamento de leite de três propriedades (leite pasteurizado tipo ¿A¿ e leite cru refrigerado), bem como, a representatividade dos diversos processos no consumo total, assunto este, ainda pouco conhecido e abordado no país. Objetivando ainda, promover a racionalização energética, avaliaram-se os potenciais de aproveitamento de calor de condensação de sistemas de refrigeração existentes para o aquecimento de água de limpeza e higienização, bem como, avaliou-se a viabilidade técnica e econômica da adequação dos sistemas (operação segundo um bomba de calor com geração simultânea de duas fontes térmicas) em substituição ao uso de resistências elétricas. Dentre as proposta, avaliou-se a adequação realizada em um planta piloto em operação. Com o uso de bomba de calor, a redução no consumo total de energia elétrica foi de até 15% com tempos de retorno dos investimentos variando entre 1,3 e 3,7 anos / Abstract: Milk is one of the most important products of Brazilian agriculture, with about 2/3 of the rural properties dedicated to the milkmaid cattle breeding and with one of the largest flocks of the world. In spite of its size, the sector still suffers of low productivity, high costs and tecnological delay. As a consequence, many producers have abandoned its activities before this new competitive technology were introduced. Now, subjects as, the use rational of energy and intensive application of technology has been discussed intensely resulting in productivity gains. In this work , it was seek to evaluate the use of energy for milk processing in three different properties (pasteurized milk type " A " and refrigerated raw milk). It was also evaluated how representativive the several processes in the total consumption were, a problem, still not very well-known and trated in Brazil. To promote the energy rationalization, the potential use of condensation heat of refrigeration systems was evaluated for the cleaning water heating, as well as, the technical and economic viability of the adaptation of the systems was evaluated (operation according to a heat pump with simultaneous generation of cold and heat) in substitution to the use of electric resistances. In the midst of proposals, an adaptation was evaluated in a pilot plant in operation. With the use of heat pumps, there was a decreasing of 15% in the consumption of eletric energy with payback between 1,3 and 3,7 years / Mestrado / Mestre em Engenharia Mecânica

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