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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.
41

Behavioral and genomic characterization of scheduled ethanol deprivation

Warner, Jonathan 08 November 2013 (has links)
Alcoholism is a persistent substance abuse disorder that is associated with negative health, social, and economic outcomes. Treatment strategies for alcohol use disorders are limited, and only three drugs have been approved by the FDA for treatment. Although behavioral therapy and drug combination strategies improve abstinence outcomes, the majority of those in treatment will not achieve long-term abstinence. Therefore, better treatment strategies are needed. While much progress has been made toward understanding the neurobiology of alcoholism, this knowledge has not been effectively translated into treatment strategies. Animal models of alcohol drinking have been crucial to this research effort, but until recently there have been few procedures that effectively model alcoholism by producing binge-like drinking, withdrawal, and relapse behavior. In the last five years the intermittent alcohol access (IAA) model, which uses repeated cycles of scheduled alcohol deprivation and reinstatement to elevate drinking, has been established as such a procedure, with substantial evidence that escalation of drinking produced by IAA is mediated by similar mechanisms as in human alcoholics, which include transcriptional regulation that alters functioning of mesolimbocortical reward pathways. The IAA model. The studies reported herein characterize changes in gene expression in mesolimbocortical brain regions associated with development of maladaptive binge-like alcohol drinking due to scheduled abstinence, particularly in the nucleus accumbens, which regulates motivated behavior. Furthermore the IAA model is characterized with regard to effectiveness in 2 ethanol-preferring C57BL/6 inbred mouse strains, and the influence of concurrent access to multiple alcohol concentrations is examined. Finally, the potential of naltrexone and novel mu-opioid receptor-selective antagonist NAQ to modulate alcohol drinking under continuous access and intermittent access procedures is reported. Microarray analysis is used to analyze the transcriptome in prefrontal cortex, nucleus accumbens, and ventral midbrain of C57BL/6NCrl mice after alcohol deprivation, and to identify differentially expressed genes and gene co-expression networks in C57BL/6J mice during continuous access, as well as after six cycles of IAA. Differentially expressed genes, network hub genes, and regulation mechanisms represent high priority targets for further study in binge-like drinking behavior, with the goal of translating this knowledge to treatment strategies for alcoholism.
42

Transport auxinu v řasách / Auxin transport in algae

Skokan, Roman January 2014 (has links)
Phytohormone auxin plays an important role in regulating plant development. Directional (polar) cell-to-cell auxin transport creates auxin gradients within plant tissues, which trigger a specific developmental response. The vast majority of available data concerns angiosperms. Lower land plants have been much less explored in this regard, but the important auxin-related mechanisms (including polar auxin transport) are already present in mosses. To uncover the origins of auxin action, one must focus on green algae, especially of clade Streptophyta, which are the direct ancestors of all land plants. In this study, the possible effects of auxins, both native and synthetic, were investigated on two algae: basal, unicellular Chlorella lobophora and advanced, filamentous Spirogyra sp. The latter received comparably more attention, since it belongs to a clade now acknowledged as a sister group to land plants. Chlorella lobophora culture growth was irresponsive to synthetic auxin NAA. The average Spirogyra sp. cell length was, however, changed by auxins at high concentrations. By conducting accumulation assays of radioactively labelled auxins and HPLC analysis, auxin metabolism and transport was investigated in Spirogyra sp. This alga was able to metabolize the plant-native IAA, but not synthetic auxins...
43

Quantificação de aminoácidos, poliaminas, AIA e ABA e marcadores protéicos na germinação de sementes de Ocotea odorifera Vell. (Lauraceae) / Quantification of amino acids, polyamines, IAA, ABA and protein markers on the germination of Ocotea odorifera Vell. (Lauraceae) seeds

Pieruzzi, Fernanda Piccolo 24 November 2009 (has links)
Ocotea odorifera é uma espécie nativa da Mata Atlântica, com características recalcitrantes, que se encontra em risco de extinção devido a sua exploração econômica. Técnicas baseadas na biotecnologia podem ser utilizadas para o processo de conservação e reintrodução no seu ambiente natural de espécies ameaçadas de extinção. Dentre as técnicas biotecnológicas, a embriogênese somática (ES) vem sendo utilizada com bastante sucesso em programas de melhoramento genético e conservação de germoplasma de espécies arbóreas. Contudo, para o estabelecimento de protocolos eficientes de ES são necessários estudos básicos de fisiologia e bioquímica do desenvolvimento da semente e da germinação, para que as condições in vivo possam ser recriadas de forma eficiente in vitro. O objetivo deste trabalho foi avaliar as variações no conteúdo endógeno de aminoácidos, PAs, AIA, ABA e estabelecer marcadores protéicos durante a germinação de sementes de O. odorifera. As sementes foram germinadas em substrato de vermiculita em fotoperíodo de 16h a 27°C. A seguir, coletadas após 0, 15, 30 e 45 dias de semeadura. Foi observado que: a) o conteúdo de aminoácidos aumentou durante o processo germinativo. A asparagina foi observada em maior quantidade e predominou durante todo o período analisado. A metionina e a ornitina, precursores das PAs, e o triptofano, precursor do AIA, aumentaram ao longo do processo germinativo; b) o conteúdo total de PAs decresceu nos últimos 15 dias de avaliação. Neste período, as poliaminas conjugadas apresentaram aumento indicando possível relação entre conjugação e disponibilidade de PAs nas células; c) a relação Put/(Spm+Spd) diminui ao final do período analisado enquanto no mesmo período a Spm foi a PA livre mais abundante indicando relação entre Spm e alongamento celular; d) O AIA apresentou aumento ao logo do processo germinativo, ao mesmo tempo em que a queda no conteúdo de ABA pode ser observada; e) o conteúdo de proteínas decresceu ao longo do processo germinativo. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Dentre esses spots incluem-se 26 que reduziram e 2 spots que aumentaram suas abundâncias ao longo do processo germinativo, 10 que apresentaram tanto aumento quanto diminuição durante o período observado e apenas 1 exclusivo da semente madura. Estes resultados abrem perspectivas para a avaliação de parâmetros fundamentais para a otimização de protocolos de ES e permitiram uma maior compreensão das variações endógenas dos diferentes compostos citados no processo germinativo das sementes de O. odorifera. / Ocotea odorifera is a native tree from the Atlantic Forest with recalcitrant features that is in risk of extinction because its economical exploration. Techniques based on biotecnology can be used for the conservation and reintroduction process of species in risk of extinction in their natural environment. Between these biotecnologycal techniques, the somatic embryogenesis (SE) have been used sucessfully in programs of genetic breeding and tree germoplasm conservation. However, basic studies of physiology and biochymical of the seed development and germination are necessary for the establishment of efficient protocols of SE. Thus, these condictions in vivo can be recriated in vitro. The aim of this work was to evaluate the variations in the endogenous content of amino acids, polyamines, IAA, ABA and protein markers throughout the seed germination of O. odorifera seeds. The seeds were germinated on vermiculite substrate at 27°C and 16h of photoperiod and collected after 0, 15, 30 e 45 days of sowing. It was observed that: a) the amino acids content increased troughout the germination process. Asparagine was the highest content sighted and prevailed during the period studied. Methionine and ornithine, polyamines precursors, and tryptophan, IAA precursor, increased troughout germination process; b) the total PAs content decreased in the last 15 days of evaluation. At the same period, conjugated PAs showed an increase, indicating a relation between conjugation and avalability of polyamines inside the cells; c) the Put/(Spm+Spd) relation decreased while the Spm was the most abundant free PA observed at the end of the period analyzed indicating a relation between Spm and celular elongation; d) IAA increased during all the process while a decrease of ABA was sigthed; e) protein content decreased troughout the period observed. The proteic profile didnt change a lot between the stages. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Among them, could be include 26 that decreased and 2 that decreased its abundances troughout the germinative process, 10 that both increased and decreased throughout the period analyzed and just 1 exclusive from mature seed. These results open perspectives to avaliation of fundamentals parameters to optmization of ES protocols and allow a better comprehension about the edogenous variation of the differents compounds citeds in the process of O. odorifera seeds germination.
44

Quantificação de aminoácidos, poliaminas, AIA e ABA e marcadores protéicos na germinação de sementes de Ocotea odorifera Vell. (Lauraceae) / Quantification of amino acids, polyamines, IAA, ABA and protein markers on the germination of Ocotea odorifera Vell. (Lauraceae) seeds

Fernanda Piccolo Pieruzzi 24 November 2009 (has links)
Ocotea odorifera é uma espécie nativa da Mata Atlântica, com características recalcitrantes, que se encontra em risco de extinção devido a sua exploração econômica. Técnicas baseadas na biotecnologia podem ser utilizadas para o processo de conservação e reintrodução no seu ambiente natural de espécies ameaçadas de extinção. Dentre as técnicas biotecnológicas, a embriogênese somática (ES) vem sendo utilizada com bastante sucesso em programas de melhoramento genético e conservação de germoplasma de espécies arbóreas. Contudo, para o estabelecimento de protocolos eficientes de ES são necessários estudos básicos de fisiologia e bioquímica do desenvolvimento da semente e da germinação, para que as condições in vivo possam ser recriadas de forma eficiente in vitro. O objetivo deste trabalho foi avaliar as variações no conteúdo endógeno de aminoácidos, PAs, AIA, ABA e estabelecer marcadores protéicos durante a germinação de sementes de O. odorifera. As sementes foram germinadas em substrato de vermiculita em fotoperíodo de 16h a 27°C. A seguir, coletadas após 0, 15, 30 e 45 dias de semeadura. Foi observado que: a) o conteúdo de aminoácidos aumentou durante o processo germinativo. A asparagina foi observada em maior quantidade e predominou durante todo o período analisado. A metionina e a ornitina, precursores das PAs, e o triptofano, precursor do AIA, aumentaram ao longo do processo germinativo; b) o conteúdo total de PAs decresceu nos últimos 15 dias de avaliação. Neste período, as poliaminas conjugadas apresentaram aumento indicando possível relação entre conjugação e disponibilidade de PAs nas células; c) a relação Put/(Spm+Spd) diminui ao final do período analisado enquanto no mesmo período a Spm foi a PA livre mais abundante indicando relação entre Spm e alongamento celular; d) O AIA apresentou aumento ao logo do processo germinativo, ao mesmo tempo em que a queda no conteúdo de ABA pode ser observada; e) o conteúdo de proteínas decresceu ao longo do processo germinativo. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Dentre esses spots incluem-se 26 que reduziram e 2 spots que aumentaram suas abundâncias ao longo do processo germinativo, 10 que apresentaram tanto aumento quanto diminuição durante o período observado e apenas 1 exclusivo da semente madura. Estes resultados abrem perspectivas para a avaliação de parâmetros fundamentais para a otimização de protocolos de ES e permitiram uma maior compreensão das variações endógenas dos diferentes compostos citados no processo germinativo das sementes de O. odorifera. / Ocotea odorifera is a native tree from the Atlantic Forest with recalcitrant features that is in risk of extinction because its economical exploration. Techniques based on biotecnology can be used for the conservation and reintroduction process of species in risk of extinction in their natural environment. Between these biotecnologycal techniques, the somatic embryogenesis (SE) have been used sucessfully in programs of genetic breeding and tree germoplasm conservation. However, basic studies of physiology and biochymical of the seed development and germination are necessary for the establishment of efficient protocols of SE. Thus, these condictions in vivo can be recriated in vitro. The aim of this work was to evaluate the variations in the endogenous content of amino acids, polyamines, IAA, ABA and protein markers throughout the seed germination of O. odorifera seeds. The seeds were germinated on vermiculite substrate at 27°C and 16h of photoperiod and collected after 0, 15, 30 e 45 days of sowing. It was observed that: a) the amino acids content increased troughout the germination process. Asparagine was the highest content sighted and prevailed during the period studied. Methionine and ornithine, polyamines precursors, and tryptophan, IAA precursor, increased troughout germination process; b) the total PAs content decreased in the last 15 days of evaluation. At the same period, conjugated PAs showed an increase, indicating a relation between conjugation and avalability of polyamines inside the cells; c) the Put/(Spm+Spd) relation decreased while the Spm was the most abundant free PA observed at the end of the period analyzed indicating a relation between Spm and celular elongation; d) IAA increased during all the process while a decrease of ABA was sigthed; e) protein content decreased troughout the period observed. The proteic profile didnt change a lot between the stages. Os perfis protéicos diferiram pouco entre os estádios analisados. Entretanto, foi observada variação significativa na abundância (% de volume) em 39 spots, que foram definidos como marcadores do processo germinativo. Among them, could be include 26 that decreased and 2 that decreased its abundances troughout the germinative process, 10 that both increased and decreased throughout the period analyzed and just 1 exclusive from mature seed. These results open perspectives to avaliation of fundamentals parameters to optmization of ES protocols and allow a better comprehension about the edogenous variation of the differents compounds citeds in the process of O. odorifera seeds germination.
45

Prospecção de rizobactérias promotoras de crescimento em quatro espécies arbóreas nativas do Brasil

Lemos, Maria Teresa Oliverio [UNESP] 01 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-01Bitstream added on 2014-06-13T19:55:59Z : No. of bitstreams: 1 lemos_mto_me_jabo.pdf: 967680 bytes, checksum: a6c9fc3231a065465ff531a2097edf51 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A conservação da biodiversidade, implica em cultivar espécies arbóreas nativas que possam ser utilizadas em projetos de reflorestamento, recuperação de áreas degradadas e com o objetivo de obter produtos secundários importantes como madeira e produtos medicinais. O uso de rizobactérias promotoras de crescimento em plantas, vem sendo muito estudado em culturas de importância econômica, devido a sua aplicabilidade em beneficiar o desenvolvimento destas. Neste trabalho foram escolhidas quatro espécies arbóreas nativas, leguminosas não nodulantes: Pterogyne nitens (Amendoim-bravo), Albizia hasslerii (Farinha-seca), Copaifera langsdorffii (Copaíba), e Stryphnodendron adstringens (Barbatimão). O objetivo deste trabalho foi avaliar in vitro as diferentes bactérias isoladas destas espécies florestais que possam ter efeito benéfico no crescimento e desenvolvimento inicial das plantas e caracterizálas pelo sequenciamento do gene 16S rRNa e perfil eletroforético do gene BOX-A 1R. As bactérias foram isoladas da rizosfera e da raiz de mudas de cada espécie, em meio de cultura NFb. No total, 29 isolados foram cultivados em meio de cultura DYGS enriquecido com triptofano. A estimativa colorimétrica do Ácido Indolacético (AIA) foi feita no espectrofotômetro, utilizando o sobrenadante da cultura de células e solução de Salkowski, com resultado positivo para o isolado Pn 6 Sphingobium chlorophenolicum com 61,69 μg.mL-1. Os isolados também foram testados para a eficiência de solubilização de fosfato de cálcio que foi realizado e contabilizado até o 15° dia após a inoculação em placas de Petri com meio de cultura NBRIP sólido, onde 27 isolados apresentaram resultados positivos. A caracterização genética permitiu a diferenciação em gêneros e também em espécies de um mesmo gênero. Os isolados que deram resultados positivos para AIA e solubilização de fosfato... / The biodiversity conservation implies cultivating native forest species that can be used in reforestation projects, recovery of degraded areas as well as getting others like wood and medicinal products. The plant growth promoting rhizobacteria (PGPR) use is being studied in cultures of economic importance. In this work four native forest species, no nodulating leguminous had been chosen: Pterogyne nitens, Albizia hasslerii, Copaifera langsdorffii, and Stryphnodendron adstringens. The aim of this work was the in vitro evaluation of the different isolates from those forest species with beneficial effects in growth and initial development of the plants and characterizes them by 16S rRNA gene sequencing and BOX-A 1R. The bacteria had been isolated from the rhizosphere and from the roots (endophytic) of each species seedlings on NFb growth media. A total of 29 isolates had been cultivated in growth media DYGS enriched with tryptophan. The indolacetic acid (IAA) production was estimated by colorimetric test in the spectrophotometer, using the supernatant of the cells culture and Salkowski´s reagent, with positive result for the isolated Pn 6 Sphingobium chlorophenolicum with 61,69 μg.mL-1. Isolates had been also tested for the efficiency of P- solubilizing that was carried through and measured until the 15 º day after the inoculation in Petri plates with solid growth media NBRIP, where 27 isolates had presented positive results. The genetic characterization allows us to differentiate by the genus and species from the same genus. The isolates that had positive results for IAA and P-solubilizing had not matched between itself, what suggests nursery tests with combinations between them to evaluate the isolate efficiency as a possible PGPRs.
46

Pseudomonas spp. Isolated from the Soybean Nodule Interior Promote Soybean Growth upon Field Amendment

Doyle, Connor Patrick 31 August 2022 (has links)
Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria (PGPR). This study observes the soybean growth promoting potential of Pseudomonas spp. in a field setting. Additionally, this study observed differences in soybean growth promotion based on amending the plant with isolated strains or a mixed culture of the species' strains. Two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were either amended with isolated strains of the novel Pseudomonas spp. (referred to as PAMW1 and BUMW2 in this study), a mix of the two strains, or an uninoculated control. The study recorded measurements to observe growth, yield, and nitrogen fixation differences. The study uses two-way factorial ANOVAs and non-parametric, multivariate analyses to determine differences in growth promotion among samples. Soybean amended with PAMW1 has greater shoot mass, biomass, and height than other treatments. Through nonmetric multidimensional scaling (NMS), samples amended with a mixed culture or PAMW1 may be different regarding growth promotion relative to the non-amended samples. Univariate results support the hypothesis that the novel Pseudomonas spp. benefit soybean in a field setting. However, it is inconclusive whether a mixed culture amendment of multiple strains alters the overall growth promotion of soybean compared to samples amended with isolated strains. / Master of Science / Soil hosts a relatively abundant and diverse community of microorganisms. Moreover, the area of soil that interacts closely with plant roots and their associated exudates, called the rhizosphere, has a significantly greater microbial abundance than surrounding bulk soil. Interactions between microbes and the plant often promote plant growth because of secondary metabolites produced by these beneficial microbes. One particular bacterial species, belonging to the Pseudomonas genus, was discovered and extracted from the soybean nodule interior. Nitrogen-fixing bacteria predominantly reside in the soybean nodule, yet this microorganism cannot fix nitrogen. Although trace amounts of non-nitrogen-fixing bacteria reside in the soybean nodule, this novel species has a relatively high abundance. This study determines the benefits of this species in the soybean nodule. Following positive results in a greenhouse study, this field experiment observes variance in soybean growth and productivity based on their received bacterial amendment. For this study, two soybean cultivars were either amended with an isolated strain of this species, a mix of the two strains, or left uninoculated to serve as a control. Numerous recorded measurements serve as indices of soybean growth and productivity. The results suggest that this novel Pseudomonas species benefits the plant by significantly improving biomass. With further research, this species can potentially serve as an environmentally sensitive and sustainable alternative to fertilizers through its ability to promote soybean growth.
47

Effect of drinking water disinfection by-products in human peripheral blood lymphocytes and sperm

Ali, Aftab H.M., Kurzawa-Zegota, Malgorzata, Najafzadeh, Mojgan, Gopalan, Rajendran C., Plewa, M.J., Anderson, Diana 26 August 2014 (has links)
No / Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. OBJECTIVES: To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses.
48

Biohemijska i fiziološka karakterizacija klonovatopole (Populus spp.) u procesu fitoekstrakcije bakra, nikla i kadmijuma / Biohemical and physiological characterization of three poplar clones (Populus spp.) during the copper, nickel and cadmium phytoextraction process

Kebert Marko 12 December 2014 (has links)
<p>Predmet ovog istaživanja&nbsp; bio je ispitivanje&nbsp;uticaja jona tri te&scaron;ka metala (Ni<sup>2+</sup>, Cu<sup>2+&nbsp;</sup>i Cd<sup>2+</sup>)&nbsp;u dve toksične koncentracije u zemlji&scaron;tu na&nbsp;fiziolo&scaron;ke i biohemijske karakteristike&nbsp;<br />odabranih klonova topola, M1, B229 i Pe 19/66.&nbsp;Ispitan je i potencijal odabranih klonova topola&nbsp;da vr&scaron;e fitoekstrakciju-akumulaciju te&scaron;kih&nbsp;metala iz zemlji&scaron;ta u svoje nadzemne delove &scaron;to&nbsp;dovodi&nbsp; do dugoročnog uklanjanja ovih&nbsp;perzistentnih polutanata iz životne sredine.&nbsp;Takođe, ispitan je uticaj te&scaron;kih metala na&nbsp;antioksidantni potencijal, sposobnost&nbsp;<br />neutalizacije slobodnih radikala, aktivnosti&nbsp;antioksidantih enzima kao i&nbsp; na sadržaj&nbsp;slobodnih i konjugovanih poliamina (Put, Spm,&nbsp;Spd),&nbsp; određenih HPLC analizom,&nbsp; i sadržaj&nbsp;biljnih hormona poput indol-3-sirćetne kiseline&nbsp;i&nbsp; abscisinske &nbsp;kiseline,&nbsp; određenih GC/MS&nbsp;analizom, u listovima i korenovima klonova topola.</p><p>&nbsp;</p> / <p>The aim of this study was to estimate and compare phytoextraction capacities of three&nbsp;poplar clones (M1, B229 and Pe 19/66) in soil. Furthermore, the goal was to assess &nbsp;different biological responses among the poplar clones during exposure to different concentration of three heavy metal ions (Ni<sup>2+</sup>, Cu<sup>2+</sup> i Cd<sup>2+</sup>). In order to track changes in&nbsp; poplars&rsquo;mineral, physiological, biochemical and antioxidant status during the&nbsp; abiotic stress, quantification of physiological properties, free and conjugated polyamines, total phenolics&nbsp; as well as quantification of phytohormones (indol-3-acetic and abscisic acid) was done. Furthermore, assessment of antioxidant potential by tracking radical scavenger capacities (RSC) against DPPH, ABTS, OH and NO radicals and by measuring enzymes activities (SOD, GSH-Px, GPx, GR) in vitro was performed in root and leaves of poplar clones.</p>
49

Désalignement des usages du système d'information dans la création et la propagation des difficultés au sein des PME : cas du secteur agro-alimentaire.

Drain, Marie-Cécile 21 January 2014 (has links) (PDF)
Cette thèse en sciences de gestion a pour objet de prendre la mesure du rôle du système d'information dans le déclenchement et la propagation des difficultés que rencontrent les petites et moyennes entreprises du secteur agro-alimentaire en France. Nous étudions le lien entre le désalignement des usages du système d'information et les difficultés que peuvent rencontrer les PME.Le terrain est constitué, d'un côté, par des enquêtes d'entreprises qui permettent de construire un indicateur synthétique de performances et, de l'autre côté, par l'enquête COI-TIC de 2006 dont nous obtenons quatre jeux d'indicateurs liés à l'usage du système d'information.À l'aide d'une démarche compréhensive, nous caractérisons ainsi le rôle du système d'information et son désalignement dans les dynamiques de performances. Nous montrons, au cas des PME des IAA, notamment l'importance de la coordination électronique (inter entreprise et entre les parties prenantes) et la place majeure des changements impliquant des projets informatiques. Enfin, les entreprises, quelles que soient leurs performances, rencontrent d'importantes difficultés d'appropriation des usages du système d'information.
50

Désalignement des usages du système d’information dans la création et la propagation des difficultés au sein des PME : cas du secteur agro-alimentaire. / Misalignments in the uses of Information Systems in triggering and propagating difficulties within small and medium-sized enterprises in the food industry in France.

Drain, Marie-Cécile 21 January 2014 (has links)
Cette thèse en sciences de gestion a pour objet de prendre la mesure du rôle du système d’information dans le déclenchement et la propagation des difficultés que rencontrent les petites et moyennes entreprises du secteur agro-alimentaire en France. Nous étudions le lien entre le désalignement des usages du système d’information et les difficultés que peuvent rencontrer les PME.Le terrain est constitué, d’un côté, par des enquêtes d’entreprises qui permettent de construire un indicateur synthétique de performances et, de l’autre côté, par l’enquête COI-TIC de 2006 dont nous obtenons quatre jeux d’indicateurs liés à l’usage du système d’information.À l’aide d’une démarche compréhensive, nous caractérisons ainsi le rôle du système d’information et son désalignement dans les dynamiques de performances. Nous montrons, au cas des PME des IAA, notamment l’importance de la coordination électronique (inter entreprise et entre les parties prenantes) et la place majeure des changements impliquant des projets informatiques. Enfin, les entreprises, quelles que soient leurs performances, rencontrent d’importantes difficultés d’appropriation des usages du système d’information. / The purpose of this thesis in management science is to assess the role of Information Systems in triggering and propagating the kind of problems faced by small and medium-sized enterprises in the food industry in France. The thesis will explore the relationship between misalignments in the uses of Information Systems and the difficulties with which SMEs are often confronted.The field of research is composed, on the one hand, of company surveys, used to elaborate a composite performance indicator, and on the other, the 2006 COI-TIC survey, from which four sets of indicators concerning the uses of Information Systems were extrapolated.Applying a comprehensive approach, the thesis defines the impact of the misalignment of Information Systems on performance dynamics. It also highlights, notably, the importance for SMEs in the food industry of IT coordination between companies and between those companies and their stakeholders, and examines the central role of changes involving IT projects. Lastly, regardless of their performances, companies face major difficulties in appropriating uses of Information Systems.

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