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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.
1

Boosting the chance of organizational change success: the role of individuals' goal orientation, affectivity and psychological capital / CUHK electronic theses & dissertations collection

January 2015 (has links)
Change management literature has not focused much on the role of individual characteristics in organizational changes. The present study examined the effect of trait-like motivational and emotional dispositions; and state-like personal resources within individuals on readiness for change. In the study, 161 Hong Kong employees completed an online questionnaire, which was designed to evaluate the employees’ perceived change efficacy in response to three scenarios (i.e. team restructuring, information system change, merger and acquisition) modified based on actual workplace change incidents as a measure of change readiness. Evidence suggested that individuals with learning goal orientation and positive affectivity particularly welcomed potential changes in their organizations. The relations were moderated by psychological capital, where change efficacy was significantly enhanced by Psychological Capital (PsyCap) for individuals with learning goal orientation and positive affectivity, implying the importance of this positive mental resource to changes at work. Further analyses on separate scenarios showed similar patterns as in the overall analyses, inferring robustness of the proposed model. Our findings shed light on employee selection; and on how strengthening employees’ PsyCap may heighten the chance of organizations undergoing changes to succeed. / 變革管理文獻並沒有太多關注員工的個人特質在組織變革上的影響。本研究目的為了解動機與情感傾向的個人特質和精神資源如何影響員工的組織變革知覺(readiness for change)。一百六十一名香港員工參與了是次研究並完成了網上問卷調查。本問卷設計用於評估員工就三種組織變革情景,即團隊架構重組、信息系統的變化和收購合併的改變效能感(perceived change efficacy),從而量化員工的組織變革知覺。研究發現,擁有學習目標導向(Learning Goal Orientation)和正向情感(Positive Affectivity)的員工會比較接受組織上的變化。再者,心理資本(Psychological Capital)有效強化學習目標導向和正向情感與組織變革知覺的關係,這意味著精神資源在工作中的重要性。研究結果揭示組織或可從員工招聘和培訓方面增進組織變化的成功機會。 / Kwan, Po Lam Polly. / Thesis M.Phil. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 33-38). / Abstracts also in Chinese. / Title from PDF title page (viewed on 14, September, 2016). / Detailed summary in vernacular field only.
2

Selection of Escherichia coli K88+ specific probiotic strains of E. coli from environmental isolates for post-weaning piglets.

Setia, Amit 12 June 2007 (has links)
Aim of this study was to select environmental E. coli isolates that produced colicins against the swine pathogen E. coli K88+. In initial evaluation using a modified plate method with 18 colicinogenic E. coli constructs, colicins E3, E4, E5, E9, Ia, K and N were found to possess inhibitory activity against 12 ETEC K88+ strains. A total of 463 environmental isolates from cattle rumen, cattle feces, pig feces and hog manure-amended soil were screened for colicin production by a modified plate test. Further, colicinogenic isolates were screened for five toxin genes LT, STa, STb, VT1 and VT2 as well as K88 (F4) fimbriae using PCR reactions. Fourteen non-pathogenic isolates were subjected to characterization of colicin genes by PCR using 9 new primer sequences, antibiotic susceptibilities and substrate utilization. Two potential probiotic strains of E. coli, UM-2 and UM-7 which produced colicins that could utilize potato starch and inulin were selected for in-vitro competition with E. coli K88+ strain 2-12. In vitro competition between the synbiotics and E. coli K88+ revealed inhibition of E. coli K88+. Based on the present in vitro studies it could be concluded that carefully selected potential synbiotics should be further studied for their role in protecting piglets from post-weaning diarrhea without antibiotics. / October 2007
3

Selection of Escherichia coli K88+ specific probiotic strains of E. coli from environmental isolates for post-weaning piglets.

Setia, Amit 12 June 2007 (has links)
Aim of this study was to select environmental E. coli isolates that produced colicins against the swine pathogen E. coli K88+. In initial evaluation using a modified plate method with 18 colicinogenic E. coli constructs, colicins E3, E4, E5, E9, Ia, K and N were found to possess inhibitory activity against 12 ETEC K88+ strains. A total of 463 environmental isolates from cattle rumen, cattle feces, pig feces and hog manure-amended soil were screened for colicin production by a modified plate test. Further, colicinogenic isolates were screened for five toxin genes LT, STa, STb, VT1 and VT2 as well as K88 (F4) fimbriae using PCR reactions. Fourteen non-pathogenic isolates were subjected to characterization of colicin genes by PCR using 9 new primer sequences, antibiotic susceptibilities and substrate utilization. Two potential probiotic strains of E. coli, UM-2 and UM-7 which produced colicins that could utilize potato starch and inulin were selected for in-vitro competition with E. coli K88+ strain 2-12. In vitro competition between the synbiotics and E. coli K88+ revealed inhibition of E. coli K88+. Based on the present in vitro studies it could be concluded that carefully selected potential synbiotics should be further studied for their role in protecting piglets from post-weaning diarrhea without antibiotics.
4

Selection of Escherichia coli K88+ specific probiotic strains of E. coli from environmental isolates for post-weaning piglets.

Setia, Amit 12 June 2007 (has links)
Aim of this study was to select environmental E. coli isolates that produced colicins against the swine pathogen E. coli K88+. In initial evaluation using a modified plate method with 18 colicinogenic E. coli constructs, colicins E3, E4, E5, E9, Ia, K and N were found to possess inhibitory activity against 12 ETEC K88+ strains. A total of 463 environmental isolates from cattle rumen, cattle feces, pig feces and hog manure-amended soil were screened for colicin production by a modified plate test. Further, colicinogenic isolates were screened for five toxin genes LT, STa, STb, VT1 and VT2 as well as K88 (F4) fimbriae using PCR reactions. Fourteen non-pathogenic isolates were subjected to characterization of colicin genes by PCR using 9 new primer sequences, antibiotic susceptibilities and substrate utilization. Two potential probiotic strains of E. coli, UM-2 and UM-7 which produced colicins that could utilize potato starch and inulin were selected for in-vitro competition with E. coli K88+ strain 2-12. In vitro competition between the synbiotics and E. coli K88+ revealed inhibition of E. coli K88+. Based on the present in vitro studies it could be concluded that carefully selected potential synbiotics should be further studied for their role in protecting piglets from post-weaning diarrhea without antibiotics.
5

Effects of Chicken Egg Anti-F4 Antibodies and a Combination of Chitosan and Probiotic Supplementation on Performance and Diarrhea Incidences in Enterotoxigenic Escherichia Coli K88+ challenged Piglets

Aluko, Kolawole 25 September 2015 (has links)
Post-weaning diarrhea is a major health challenge in the swine industry and is routinely managed by fortifying pig starter diets with antimicrobials. But there are concerns about antibiotic resistance, hence the need for identifying effective alternatives. The use of spray-dried whole egg powder containing anti-F4 antibodies (SDWE) against recombinant F4 antigens and chitosan oligosaccharide and Enterococcus fecalis probiotic combination (CPRO) was investigated in two trials using enterotoxigenic Escherichia coli K88+ (ETEC) oral challenge model in 21-d-old piglets. Pre-challenge, SDWE supported higher (P < 0.05) piglet performance whereas during the post-challenge period, SDWE and CPRO had no effect on growth performance but diarrhea incidences and severity were reduced (P > 0.05) in SDWE-fed piglets compared to the control. The results show that SDWE supported greater piglet performance pre-ETEC challenge although there was no benefit of SDWE or CPRO supplementation evident during the post-challenge period in early-weaned pigs. / October 2015
6

Gut microbiome analysis in piglet models infected with Escherchia coli K88: the role of charcoal and dietary crude protein supplemented with probiotic Escherchia coli strains UM2 and UM7.

Meshkibaf, Shahab 08 September 2011 (has links)
Entrotoxigenic Escherichia coli (ETEC) K88 is a causative agent of post-weaning diarrhea (PWD) in early-weaned pigs. This study investigated the efficacy of two alternative diets, charcoal (0.1, 0.5, 1, and 2%) and a low crude protein (CP) diet (17%) supplemented with probiotic E. coli strains (UM2 and UM7), against PWD infection in ETEC K88 challenged piglets. The present study found that charcoal had no effect on the challenged piglets’ performance, ileal and colonic microbiota or their fermentation end products. There was, however, a correlation between charcoal dosage and fecal consistency score. Charcoal reduced the ileal mucosal attached ETEC K88. Feeding a low-CP diet resulted in a lower ileal ammonia concentration. The low-CP diet reduced the E. coli populations in the ileal digesta as well as lowered mRNA expression of the IL-1ß. We concluded that the use of both 1-2% charcoal diet and a low-CP diet supplemented with probiotic E. coli strains were effective in reducing the incidence and severity of PWD infection.
7

Gut microbiome analysis in piglet models infected with Escherchia coli K88: the role of charcoal and dietary crude protein supplemented with probiotic Escherchia coli strains UM2 and UM7.

Meshkibaf, Shahab 08 September 2011 (has links)
Entrotoxigenic Escherichia coli (ETEC) K88 is a causative agent of post-weaning diarrhea (PWD) in early-weaned pigs. This study investigated the efficacy of two alternative diets, charcoal (0.1, 0.5, 1, and 2%) and a low crude protein (CP) diet (17%) supplemented with probiotic E. coli strains (UM2 and UM7), against PWD infection in ETEC K88 challenged piglets. The present study found that charcoal had no effect on the challenged piglets’ performance, ileal and colonic microbiota or their fermentation end products. There was, however, a correlation between charcoal dosage and fecal consistency score. Charcoal reduced the ileal mucosal attached ETEC K88. Feeding a low-CP diet resulted in a lower ileal ammonia concentration. The low-CP diet reduced the E. coli populations in the ileal digesta as well as lowered mRNA expression of the IL-1ß. We concluded that the use of both 1-2% charcoal diet and a low-CP diet supplemented with probiotic E. coli strains were effective in reducing the incidence and severity of PWD infection.
8

Caracterização de um novo fator de colonização (FC O25) de Escherichia coli isoladas de colibacilose neonatal bovina / Characterization of a new colonization (CF O25) of Escherichia coli isolated from neonatal bovine colibacillosis

Valadares, Georgio Freesz 07 August 2018 (has links)
Orientador: Domingos da Silva Leite / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-07T11:06:07Z (GMT). No. of bitstreams: 1 Valadares_GeorgioFreesz_D.pdf: 5633139 bytes, checksum: eb53d324f81f52cd2327efa730c3e888 (MD5) Previous issue date: 2006 / Resumo: Infecções por Escherichia coli são freqüentes em animais domésticos, afetando principalmente animais recém nascidos e no período do pós-desmame, sendo responsáveis por importantes danos econômicos na suinocultura e pecuária de bovinos e ovinos. A instalação da bactéria ao hospedeiro se dá através da colonização, processo mediado por proteínas denominadas adesinas, que se encontram distribuídas por toda a superfície bacteriana. Estas apresentam uma grande variedade morfológica e são coletivamente chamadas de Fatores de Colonização (FCs). Neste trabalho identificamos um novo fator de colonização (FC O25) presente em cepas de Escherichia coli isoladas de casos de colibacilose neonatal bovina, que apresenta semelhanças antigênicas com os FCs F4(K88), CS31A e F41 sem, contudo, apresentar identidade genética com estes fatores em ensaios de PCR. Baseados nessas homologias, investigamos a hipótese do FC O25 pertencer a esta família de FCs. Estudamos a seqüência do gene que compõe a subunidade principal do FC O25 com base em semelhanças com genes dos fatores de colonização homólogos e encontramos o FC O25 presente em 35 das 41 cepas em estudo. Verificamos que a proteína FC O25 apresenta 49,7% de homologia com a proteína FaeG (F4), 35,4% com ClpG (CS31A) e 29,4% com FimF41. Com ferramentas de bioinformática determinamos a relação filogenética entre essas proteínas e a estrutura secundária do FC O25. Os estudos de extração de DNA genômico e plasmidial indicaram que o gene FC O25 deve estar localizado no cromossomo bacteriano. Este foi clonado no vetor de expressão pET-151, inserido na linhagem de E.coli BL21[DE3]-Star e a proteína do FC O25 foi obtida e purificada e antissoro policlonal monoespecífico foi obtido em coelho. A proteína do FC O25 purificada foi submetida a ensaios de Western Blotting frente a antissoros anti os FCs F4, F41 e CS31A e verificamos reconhecimento da proteína em diferentes graus. A cepa CG1905-B foi utilizada em ensaios de microscopia eletrônica de transmissão com marcação por anticorpos conjugados com ouro e verificamos que a estrutura do FC O25 é do tipo fibrilar assemelhando-se à estrutura do CS31A. Em ensaios de adesão a linhagens de células eucarióticas in vitro observamos adesão às células Caco-2 (carcinoma de cólon humano) e que esta adesão era inibida pelo antissoro anti-FC O25. Os resultados sugerem que o FC O25 pode ser importante para a patogenicidade das E. coli bovinas no Brasil, uma vez que encontramos uma associação deste com outros fatores de colonização e, sobretudo com toxinas relacionadas com a patogenia em bovinos, evidenciando novas relações entre mecanismos de virulência que merecem novas investigações, além da própria elucidação completa da estrutura do operon FC O25 / Abstract: Infections from Escherichia coli are frequent in domestic animals, affecting mainly newborn animals in the post weaning period, being thus responsible for important economic losses in the cattle, porcine and lamb herds. The establishment of the bacterium in the host is made by colonization and it is a process mediated by proteins called adhesins that are distributed along the bacterial surface. They present a great morphological variety and are called Colonization factors (CFs). Our objective in this work was to identify the new colonization factor (CF O25) in Escherichia coli strains isolated from bovine neonatal colibacillosis, this CF O25 presents antigenic similarities with the FCs F4(K88), CS31A and F41 without, however, present genetic identity to these factors in PCR assays. Based in these homologies, we investigated the hypothesis of the NFC be a member of this "family" of CFs. So we studied the sequence of the CF O25¿s main subunit gene and its similarities with the genes of the homologous CFs (F4, F41 and CS31A) in polymerase chain reaction (PCR) assays. We found the CF O25 in 35 of the 41 studied strains. Through DNA sequencing, we verified that CF O25 protein presents 49.7% of homology with FaeG protein (F4), 35.4% with ClpG (CS31A) and 29.4% with FimF41. Using bioinformatics tools we determined the phylogenetic relationships between these proteins and the secondary structure of the CF O25. The genomic and plasmid DNA extraction assays indicates that the CF O25 gene is located in the bacterial chromosome. The CF O25 gene was cloned in the pET-151 expression vector, inserted in the E.coli BL21[DE3]-Star strain and the CF O25 protein was over expressed, purified and monospecific antiserum was obtained in rabbits. The purified CF O25 protein was submitted to Western Blotting assays with antissera against the FCs F4, F41 and CS31A and we verified recognition of the CF O25 in different degrees. The CG1905-B strain was used in the assays of electronic transmission microscopy using immunogold. The structure of the PCF is fibrillar resembling it the structure of the CS31A. This strain also was submitted the assays of adhesion to the eukaryotic culture cells and we observed adhesion to the Caco-2 cells (human colon carcinoma), this adhesion could be inhibited by anti-CFO25 antiserum. Our results suggest that the CF O25 can be important for the bovine pathogenicity of E. coli in Brazil, since we found CF O25 associated with other colonization factors and toxins, related with patogenicity in bovines, evidencing new relationships between virulence mechanisms that deserve new investigations, as well the elucidation of the complete structure of CF O25 operon / Doutorado / Microbiologia / Doutor em Genetica e Biologia Molecular
9

Ombre et lumière dans la ville : le potentiel de l'image numérique pour l'exploration et l'analyse des ambiances lumineuses nocturnes

Koulouris, Véronique 15 April 2019 (has links)
S'inscrivant dans le champ de recherche émergeant sur les ambiances lumineuses, cette recherche s'intéresse au potentiel de l'image numérique pour l'exploration et l'analyse de la lumière dans le paysage urbain nocturne. À partir de relevés effectués dans les villes de Québec et de Montréal, comme autant d'images qui se succèdent à l'échelle du piéton, le projet propose d 'évaluer l'image numérique 2D comme outil permettant des analyses et explorations quantitatives et qualitatives des espaces urbains éclairés. La méthodologie employée s'appuie sur la recherche développée par Demers [1997]. Le potentiel créatif du médium pour la conception lumière est également abordé. Parallèlement, la recherche propose de développer une démarche spécifique au contexte de la lumière urbaine nocturne afin de cerner différents aspects qui composent les ambiances lumineuses nocturnes, tels que les effets de la lumière sur les formes urbaines (espaces ou objets architectures). Les outils de relevés employés présentent l'avantage d'être accessibles autant pour le chercheur que pour le concepteur lumière. Ils ont fait l'objet d'explorations afin de déterminer leurs limites dans des conditions d'éclairage nocturne. Il s'agit de la photographie à l'aide d'une caméra réflexe 35 mm et de la vidéo. Des outils de mesures de la lumière tel qu'un photomètre ainsi que des posemètres manuels complètent les besoins de la recherche. Les images numérisées sont traitées à l'aide du logiciel Adobe Photoshop. / Québec Université Laval, Bibliothèque 2019
10

La société mondiale comme problème dans la philosophie politique d'Éric Weil

Kouakou, Amoa 25 April 2018 (has links)
Dans Sept études sur Eric Weil, Gilbert Kirscher et Jean Quillien considèrent l'oeuvre philosophique d'Eric Weil comme "l'une des plus importantes de la seconde moitié du XXe siècle ". Très pénétré par les grandes philosophies du passé, celles d'Aristote, de Kant et de Hegel, Eric Weil les a en effet repensées en fonction des problèmes contemporains. Ainsi les thèmes de la violence, de la société et de l'Etat sont-ils repris en profondeur et de façon systématique. Cette thèse se propose de faire de ces thèmes une présentation d'ensemble. Une première distinction s'impose entre la société moderne et l'Etat. Toute société est "essentiellement en lutte avec la nature extérieure" et, par conséquent, est une communauté de travail. En plus de posséder ce caractère, la société moderne est moderne parce qu'elle se connaît comme société: elle se veut rationnelle, tournée vers l'efficacité et est inévitablement "calculatrice, matérialiste et mécaniste". En principe, la société moderne est mondiale car les modes de production, de distribution et de maîtrise de la nature ainsi que l'économie sont partout identiques, l'individu dans cette société trouve sa sécurité mais non le sens de son existence. Il est déchiré. De plus la société moderne s'oppose radicalement à l'Etat. Celui-ci est l'organisation d'une communauté historique. Il présente deux aspects. L'Etat moderne est absorbé par des conflit s avec les autres États ou tout au moins engagé dans une compétition qui l'oblige à exiger des citoyens une loyauté totale. A ce point de vue, l'Etat est agressif et autoritaire. Mais il est aussi comme Etat le lieu de l'amitié et, selon l'enseignement des Anciens, celui de la vertu. Ce second aspect est complètement annulé par le premier. La perspective d'institutions mondiales qui prolongeraient la société moderne pourrait cependant, selon Eric Weil, permettre à l'Etat d'assumer son rôle véritable : éduquer à l'universel concret et rendre possible la vie sensée. L'Etat redeviendrait ce qu'était la cité grecque. Seul le point de vue autarcique aurait été abandonné. La société mondiale comporte certes des risques, mais la liberté recherchée justifie qu'on accepte ces risques.

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