• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 20
  • 7
  • 7
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 59
  • 13
  • 13
  • 11
  • 11
  • 11
  • 10
  • 10
  • 9
  • 9
  • 7
  • 6
  • 6
  • 6
  • 6
  • 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.
31

Rôle du facteur de transcription p53 dans l'infection des macrophages humains par le VIH-1

Breton, Yann 02 February 2024 (has links)
À ce jour, malgré les traitements antirétroviraux efficaces permettant de contrôler la charge virale chez les personnes vivant avec le VIH-1, aucun vaccin ni traitement curatif n'est disponible. La recherche fondamentale est donc toujours de mise afin de mieux comprendre les mécanismes moléculaires permettant la persistance du virus. Les macrophages, l'une des cellules cibles du VIH-1, jouent un rôle important dans l'établissement de l'infection et la propagation du virus. Étant présentes dans les muqueuses, ces cellules sont parmi les premières à être exposées au VIH-1 lors de l'infection. En combinaison avec leur longue durée de vie et leur résistance à l'effet cytopathique du virus, les macrophages doivent être pris en considération dans le développement d'une stratégie de guérison. De plus, ces cellules font partie des réservoirs viraux, c'est-à-dire des cellules qui persistent chez la personne infectée malgré les thérapies antirétrovirales, et participent au rebond de la charge virale lors de l'arrêt des traitements. Les macrophages sont caractérisés par un faible taux d'infection in vitro. Afin d'identifier les facteurs de l'hôte associés à une susceptibilité ou une résistance à l'infection, nous avons fait une étude comparant le transcriptome de cellules infectées par le VIH-1 avec la population exposée ayant résisté à l'infection (population spectatrice), suivie d'un criblage d'ARN interférents envers une sélection de gènes modulés par le virus. Cette étude a permis de mettre en évidence plusieurs facteurs de régulation du VIH-1, dont la protéine MDM2. MDM2 est une ubiquitine ligase impliquée dans la réponse aux dommages à l'ADN et régulant le niveau de plusieurs protéines, sa cible principale étant le facteur de transcription p53. Les deux études présentées dans cette thèse de doctorat cherchent à mieux comprendre le rôle des protéines MDM2 et p53 dans l'infection des macrophages humains par le VIH-1. Nous démontrons d'abord que l'ubiquitine ligase MDM2 favorise l'infection productive des macrophages via le contrôle de p53. En effet, la stabilisation du facteur de transcription p53 induit l'expression de la protéine p21, qui à son tour empêche la phosphorylation de la protéine SAMHD1. SAMHD1 est un facteur de restriction efficace chez le macrophage, interférant avec l'étape de transcription inverse du virus, et est inactivé suivant sa phosphorylation. Un niveau plus élevé de p53 dans la cellule entraîne donc en une plus forte restriction de l'infection par le VIH-1. Cette première étude a mis en lumière un rôle antiviral de p53 et l'importance de son contrôle par MDM2 pour le VIH-1. Notre seconde étude découle directement des résultats obtenus lors de la première. Le gène TP53 exprime plusieurs isoformes de p53, chacune connue pour moduler l'activité de p53 pleine longueur. Nous démontrons que ces isoformes peuvent aussi moduler le cycle viral de manière distincte. Par exemple, l'interférence par ARN de l'isoforme p53β cause un effet similaire à l'ARN interférent ciblant toutes les isoformes, mais cette hausse de l'infection est seulement observée au niveau de la production de virions et n'affecte pas le taux d'infection. Cet effet serait aussi indépendant de l'action de SAMHD1. L'inhibition de l'expression des isoformes Δ133p53, quant à elle, diminue la susceptibilité des macrophages au VIH-1 et dépend du sentier p53/SAMHD1. Dans cette étude, nous montrons aussi que la protéine virale Nef protège le virus de l'action de p53. Enfin, nous avons observé une modulation de l'expression des isoformes de p53 suivant l'infection par le VIH-1, certaines isoformes étant modulées spécifiquement chez les macrophages productivement infectés. Ensemble, ces études mettent en lumière un rôle dans l'immunité innée antivirale pour le facteur de transcription p53, plutôt connu pour ses propriétés antitumorales. La mise en évidence d'un nouveau facteur de régulation du VIH-1 spécifique au macrophage et impliqué dans les étapes menant à l'intégration du VIH-1 dans ces cellules permet une meilleure compréhension des mécanismes moléculaires menant à la formation et à la persistance de réservoirs viraux. Ces études permettront d'envisager de nouvelles voies thérapeutiques pour prévenir leur formation et mener à l'éradication du virus. Nos résultats permettent aussi de mieux comprendre l'implication de p53 dans l'immunité ainsi que l'importance de son contrôle par MDM2 et pourront aussi être transposées dans d'autres sphères de la virologie. Inversement, les connaissances actuelles en oncologie sur le facteur de transcription p53 pourront être transposées pour développer de nouvelles thérapies et, éventuellement, une guérison de l'infection par le VIH-1. / To date, despite effective antiretroviral therapies for viral load control in people living with HIV-1, no vaccine or cure against the virus is available. Basic science research is then still necessary to better understand the molecular mechanisms allowing the viral persistence. Macrophages, one of the cells targeted by HIV-1, play an important role in the establishment and propagation of HIV-1 infection. Being present in the mucous membranes, macrophages are among the first cells exposed to the virus upon infection. In combination with their long lifespan and their resistance to HIV-1-mediated cytopathogenic effects, macrophages must be considered for the development of a functional cure. In addition, these cells are part of the viral reservoirs, which are cells that persist in the infected person despite antiretroviral therapy and are responsible for the return of the viremia when treatments are stopped. Macrophages are characterized by their low infection rate in vitro. To identify host factors associated with the susceptibility or resistance to infection, we did a transcriptomic study comparing the infected cells with the bystander population (i.e., cells exposed to HIV-1 but uninfected), followed by a siRNAs screening of genes modulated by HIV-1 infection. This study revealed several positive and negative HIV-1 regulatory factors. One of these regulators was MDM2. MDM2 is a ubiquitin ligase involved in the DNA damage response and regulating the turnover of various proteins, including p53. The main goal of the two studies presented in this Ph.D. thesis is to better understand the role of MDM2 and p53 in the infection of macrophages by HIV-1. We demonstrate that the MDM2 ubiquitin ligase favors HIV-1 replication through the control of p53. Indeed, p53 stabilization induces the expression of p21, which in turn inhibits the phosphorylation of SAMHD1. SAMHD1 is an important restriction factor in macrophages, interfering with HIV-1 reverse transcription, and is inactivated by phosphorylation. A higher level of p53 thus results in a stronger restriction against HIV-1 mediated by SAMHD1. This first study highlights an antiviral role of p53 and the importance of its control by MDM2 for HIV-1infection. Our second study stems from the results obtained in our first one. The TP53 gene expresses multiple isoforms of p53, each known to modulate the full-length p53 activity. We demonstrate that these isoforms can also modulate the HIV-1 replication cycle in a distinct manner. For example, RNA interference of the p53β isoform cause a similar effect than the siRNA targeting all the isoforms, but the increase is only seen on the viral production and not on the infection rate. This effect also seems to be SAMHD1-independent. Knockdown of Δ133p53 isoforms, on the other hand, decreases the susceptibility of macrophages towards HIV-1 in a p53/SAMHD1-dependant manner. In this study, we also show that the viral protein Nef protects the virus from the antiviral activity of p53. Finally, we observe a change in the p53 isoforms expression pattern upon exposure to HIV-1, certain isoforms being modulated specifically in the productively infected macrophages. Together, these studies highlight an antiviral role for the transcription factor p53, better known for its antitumor functions. The demonstration of a new regulatory factor of HIV-1infection specific to the macrophages and involved in the replication steps leading to the viral genome integration allows a better understanding of the molecular mechanisms leading to the formation and persistence of HIV-1 reservoirs. These studies will open the way to new therapeutic routes to prevent their formation and lead to the eradication of the virus. Our results also provide a better understanding of the involvement of p53 in immunity and the importance of its control by MDM2 and may also be transposed into other areas of virology. Conversely, current knowledge in oncology on the p53 transcription factor could be used in the development of new therapies and, possibly, a cure against HIV-1.
32

Détérioration respiratoire en sortie d'aplasie sous facteur de croissance hématopoïétique (G-CSF) à propos de 20 cas /

Karlin, Lionel. Azoulay, Elie January 2004 (has links) (PDF)
Thèse d'exercice : Médecine. Réanimation médicale : Paris 12 : 2004. / Titre provenant de l'écran-titre. Bibliogr.
33

Behavioural Inhibition in Children with ADHD: Does Stimulant Medication Eliminate Potential Deficits?

Caroline Johnson Unknown Date (has links)
Attention-Deficit / Hyperactivity Disorder (ADHD) is characterized by higher than normal levels of inattention, hyperactivity and impulsivity. Behavioural inhibition is proposed to be a primary deficit in children with ADHD, and is included as a component of a number of models accounting for the core behavioural symptoms of ADHD. Children with ADHD often show deficits in their performance on behavioural inhibition tasks relative to typically developing children of the same age, although inconsistent findings have been observed. Stimulant medication is associated with reduction in the core symptoms of ADHD in the majority of children. The primary goal of this thesis was to examine the effects of stimulant medication on behavioural inhibition in children with ADHD. Furthermore, this thesis sought to determine whether children with ADHD who have, and have not taken stimulant medication differ from normally developing children in terms of behavioural inhibition. In order to achieve these aims, it was necessary to firstly determine which tasks provide the best measures of behavioural inhibition. While many tasks have been used to measure inhibitory control amongst children with ADHD, it was unclear from previous research which tasks measure the same constructs. Study 1 investigated relationships in task performance among seven measures of inhibitory control, including the Stop-Signal task, Go / No-go task, Sustained Attention to Response Task (SART; analogous the not-X Continuous Performance Task), Eriksen Flanker task, Stroop, Opposite Worlds task and Task-Switching task. Significant developmental changes in a variety of cognitive abilities occur across childhood and adolescence. To limit the possibility that developmental changes in task performance would be observed, the age range for children included in the study was restricted to seven to 10 years. Nevertheless, to interpret correlations among inhibition measures from the tasks, it was necessary to determine whether children showed comparable developmental trends in their performance across tasks. Study 1A investigated developmental changes in the performances of the seven tasks purported to measure inhibitory control in normally developing children aged seven to 10 years. The results of this study suggested that the tasks chosen were appropriate for use among this age group, and that there is little change in behavioural inhibition across the seven to 10 years age range. In Study 1B, inhibition measures from each of the tasks were included in an exploratory factor analysis to determine those tasks measuring the same constructs. The results of Study 1B suggested that the Stop-Signal, Go / No-go and SART tasks provided the best measures of the behavioural inhibition construct. Performance on the Eriksen Flanker task was also related to the performance on these tasks, but in a direction contrary to that predicted. The Stroop and Opposite Worlds tasks measured the same construct, which appeared to be interference control. Performance on the Task-Switching task was not related to the performance on any other task, suggesting that this task did not measure behavioural inhibition or interference control. Study 2 investigated the performance of children with ADHD on the three tasks shown to be the best measures of behavioural inhibition in Study 1B (i.e., the Stop-Signal task, Go / No-go task and Sustained Attention to Response task). Children with ADHD were aged from seven to 11 years, and were tested both when they had, and had not taken their regularly prescribed stimulant medication. The performance of children with ADHD on these tasks was compared to that of normally developing children matched in age. The results of Study 2 suggested that stimulant medication leads to significant improvement in behavioral inhibition amongst children with ADHD, such that children with ADHD do not differ from matched controls. However, this effect was not observed across all three tasks. Reasons for this, along with study limitations, and directions for future research are discussed.
34

Behavioural Inhibition in Children with ADHD: Does Stimulant Medication Eliminate Potential Deficits?

Caroline Johnson Unknown Date (has links)
Attention-Deficit / Hyperactivity Disorder (ADHD) is characterized by higher than normal levels of inattention, hyperactivity and impulsivity. Behavioural inhibition is proposed to be a primary deficit in children with ADHD, and is included as a component of a number of models accounting for the core behavioural symptoms of ADHD. Children with ADHD often show deficits in their performance on behavioural inhibition tasks relative to typically developing children of the same age, although inconsistent findings have been observed. Stimulant medication is associated with reduction in the core symptoms of ADHD in the majority of children. The primary goal of this thesis was to examine the effects of stimulant medication on behavioural inhibition in children with ADHD. Furthermore, this thesis sought to determine whether children with ADHD who have, and have not taken stimulant medication differ from normally developing children in terms of behavioural inhibition. In order to achieve these aims, it was necessary to firstly determine which tasks provide the best measures of behavioural inhibition. While many tasks have been used to measure inhibitory control amongst children with ADHD, it was unclear from previous research which tasks measure the same constructs. Study 1 investigated relationships in task performance among seven measures of inhibitory control, including the Stop-Signal task, Go / No-go task, Sustained Attention to Response Task (SART; analogous the not-X Continuous Performance Task), Eriksen Flanker task, Stroop, Opposite Worlds task and Task-Switching task. Significant developmental changes in a variety of cognitive abilities occur across childhood and adolescence. To limit the possibility that developmental changes in task performance would be observed, the age range for children included in the study was restricted to seven to 10 years. Nevertheless, to interpret correlations among inhibition measures from the tasks, it was necessary to determine whether children showed comparable developmental trends in their performance across tasks. Study 1A investigated developmental changes in the performances of the seven tasks purported to measure inhibitory control in normally developing children aged seven to 10 years. The results of this study suggested that the tasks chosen were appropriate for use among this age group, and that there is little change in behavioural inhibition across the seven to 10 years age range. In Study 1B, inhibition measures from each of the tasks were included in an exploratory factor analysis to determine those tasks measuring the same constructs. The results of Study 1B suggested that the Stop-Signal, Go / No-go and SART tasks provided the best measures of the behavioural inhibition construct. Performance on the Eriksen Flanker task was also related to the performance on these tasks, but in a direction contrary to that predicted. The Stroop and Opposite Worlds tasks measured the same construct, which appeared to be interference control. Performance on the Task-Switching task was not related to the performance on any other task, suggesting that this task did not measure behavioural inhibition or interference control. Study 2 investigated the performance of children with ADHD on the three tasks shown to be the best measures of behavioural inhibition in Study 1B (i.e., the Stop-Signal task, Go / No-go task and Sustained Attention to Response task). Children with ADHD were aged from seven to 11 years, and were tested both when they had, and had not taken their regularly prescribed stimulant medication. The performance of children with ADHD on these tasks was compared to that of normally developing children matched in age. The results of Study 2 suggested that stimulant medication leads to significant improvement in behavioral inhibition amongst children with ADHD, such that children with ADHD do not differ from matched controls. However, this effect was not observed across all three tasks. Reasons for this, along with study limitations, and directions for future research are discussed.
35

Le rôle de l'inflammation et des microglies dans la sclérose latérale amyotrophique = The role of inflammation andm microglia in amyotrophic lateral sclerosis /

Gowing, Geneviève. January 2009 (has links) (PDF)
Thèse (Ph. D.)--Université Laval, 2009. / Bibliogr.: f. 182-212. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.
36

Desempenho de bioestimulantes e sua viabilidade econômica na cultura da soja / Performance of the biostimulants and ecnonomic viability in soybean

Faria, Tatiana Carvalho 14 February 2017 (has links)
Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-03-14T20:18:05Z No. of bitstreams: 2 Dissertação - Tatiana Carvalho Faria - 2017.pdf: 775476 bytes, checksum: 88bec79d421176f3ad69d8af7193d38f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-03-20T12:31:19Z (GMT) No. of bitstreams: 2 Dissertação - Tatiana Carvalho Faria - 2017.pdf: 775476 bytes, checksum: 88bec79d421176f3ad69d8af7193d38f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-03-20T12:31:19Z (GMT). No. of bitstreams: 2 Dissertação - Tatiana Carvalho Faria - 2017.pdf: 775476 bytes, checksum: 88bec79d421176f3ad69d8af7193d38f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of biostimulants has been widely applied in agricultural production, in soybean especially, and perform an important role in the growth and development of plants. The present study objectified to evaluate the biostimulants in soybean, about the application time and the environment, considering the agronomic aspects, productivity and economic viability. Two experiments were implanted, one in the greenhouse and other in the field. The design was completely randomized, factorial 6 x 3 with 4 repetitions. The treatments were: control, without product application; Stimulate® , 250 mL ha-1 ; Matrix G® , 200 mL ha-1 ; Vitakelp® , 250 mL ha-1 ; Agrostemin® , 30g ha-1 ; Improver® , 120 mL ha-1 . The times of application were in seed treatment, to 40 or 60 days after sowing. In the greenhouse, the control, Agrostemin® and Improver® obtained the same mean of the first legume insert and were higher to Vitakelp® . In the dry root mass, the Matriz G® was higher than Vitakelp® . In the field, in relation to first legume insert the Agrostemin® was better than the Improver® and Stimulate® , the Matriz G® surpassed the Improver® and the application via seed and 60 days after sowing were better. In relation to plant height in seed treatment, the control and the Stimulate® were better than Matriz G® and the Improver® . When applied 40 days after sowing, the Stimulate® had greater height than the Matriz G® . In this variable the best time for of the products application was 40 days after sowing. In number of branches, in the seed treatment, the control and the Stimulate® had more branches than Vitakelp® and Improver® . In the analysis of joint variance of the experiments the height of first legume insert, number of pods, grains and branches per plant, grain mass and productivity were better at greenhouse. Plant height stood out in the field. All treatments were better in the field at plant height and better at greenhouse in grain mass and productivity. It is concluded that the climate, nutritional and health conditions favorable for the crop cycle attenuate the effects of biostimulants in plants. The first legume insert, plant height, root dry mass and number of branches per plant, the biostimulants contribute positively. The application time influences the first legume insert, plant height and number of branches per plant, increasing them. Growing in a greenhouse brings better results. The use of biostimulants is not economically viable. / O uso de bioestimulante tem sido amplamente aplicado na produção agrícola, especialmente em soja, e desempenha um papel importante no crescimento e desenvolvimento da planta. O presente trabalho objetivou avaliar bioestimulantes em soja, segundo a época de aplicação e ambiente, atentando para os aspectos agronômicos, produtividade e viabilidade econômica. Foram implantados dois experimentos sendo um em ambiente com telado e outro no campo. O delineamento foi inteiramente ao acaso, esquema fatorial 6 x 3, com 4 repetições. Os tratamentos foram: testemunha, sem aplicação de produto; Stimulate® , 250 mL ha-1 ; Matriz G® , 200 mL ha-1 ; Vitakelp® , 250 mL ha-1 ; Agrostemin® , 30g ha-1 ; Improver® , 120 mL ha-1 . As épocas de aplicação foram: em tratamento de sementes, aos 40 ou 60 dias após o semeio. Em telado, a testemunha, o Agrostemin® e o Improver® obtiveram a mesma média de altura de inserção de primeira vagem e foram superiores ao Vitakelp® . Em relação à massa seca de raiz, o Matriz G® foi superior ao Vitakelp® . No campo, em relação à altura de inserção de primeira vagem o Agrostemin® foi melhor que o Improver® e o Stimulate® , o Matriz G® superou o Improver® e a aplicação via semente e com 60 dias após o semeio foram melhores. Em relação à altura de planta, em tratamento de sementes, a testemunha e o Stimulate® foram melhores que o Matriz G ® e o Improver® . Quando aplicados aos 40 dias após o semeio, o Stimulate® teve maior altura que o Matriz G® . Nesta variável a época melhor para aplicação dos produtos foi aos 40 dias após o semeio. Em número de ramos por planta, no tratamento de sementes, a testemunha e o Stimulate® tiveram mais ramificações que o Vitakelp® e o Improver® . Na análise de variância conjunta dos experimentos a altura de inserção de primeira vagem, número de vagens, grãos e ramos por planta, massa de grãos e produtividade foram melhores em ambiente com telado. A altura de planta se destacou no campo. Todos os tratamentos foram melhores no campo em altura de planta e melhores em telado na massa de grãos e produtividade. Concluiu-se que as condições climáticas, nutricionais e sanitárias favoráveis durante o ciclo da cultura atenuam os efeitos dos bioestimulantes nas plantas. A altura de inserção de primeira vagem, altura de planta, massa seca de raiz e número de ramos por planta, os bioestimulantes contribuem de forma positiva. A época de aplicação influencia, aumentando a altura de inserção de primeira vagem, altura de planta e número de ramos por planta. O cultivo em ambiente com telado traz melhores resultados. Não é viável economicamente o uso de bioestimulantes.
37

The Academic Steroid: Nonmedical Use of Prescription Stimulants at a North Texas University

Pennington, Cody W. 12 1900 (has links)
The goal of this study was to determine the extent, motivations, and justifications of nonmedical prescription stimulant use among the population at a large public university in the North Texas region. Participants consisted of 526 undergraduate students enrolled at the studied university during the spring and summer 2014 semesters. The findings of the study suggest that the nonmedical use by students was higher than the findings in much of the current literature, but was within the parameters established in the literature. The primary motivation for nonmedical use was academic in nature and was justified by moderation of nonmedical use to strategic academic times.
38

Fertilizante Natural: Agro Dust / Natural Fertilizer: Agro Dust

Avendaño Gil, Gianfranco Emilio, Bazán Durand, Daniel Antonio, Maza Fajardo, Rodrigo Alonso, Ochoa Bustamante, Juan Diego, Torres Paredes, Maria Elizabeth 27 November 2019 (has links)
El presente proyecto se basa en la producción y comercialización de fertilizante natural y biodegradable, que sirve como bio-estimulante para las plantas ornamentales, teniendo como valor adicional ser un retenedor de agua de riego durante 20-21 días aplicando una sola vez el producto. Elaborado a base de cáscara de naranja y palta, nuestro negocio va dirigido a habitantes de Lima Moderna correspondientes a los estilos de vida conservador, moderno y sofisticado que posean plantas y/o pequeños jardines pertenecientes a los niveles socioeconómicos (NSE) A, B y C, además de mostrar preocupación por el medio ambiente. El empaque del producto va a ser una bolsa de papel kraft biodegradable con una capacidad 250 gramos. Se realizó una total de entrevistas a 30 personas para validar la existencia del problema encontrado y el interés e intención de uso del producto de nuestros posibles clientes. Además, con fines de hacer este proyecto escalable para el rubro de la agricultura, se contactó a dos expertos en agronomía para validar el producto y algunos aspectos sobre la posible escalabilidad de este. El desarrollo del proyecto se encuentra dividido en dos puntos, los cuales son la validación del plan de negocio y desarrollo del plan de negocio. Para la ejecución del proyecto se requirió una inversión de 21,454 soles, obtenidos a base de capital propio de los accionistas, quienes estiman recuperar dicha inversión en el primer año de operación. La rentabilidad brindada a los accionistas es de 249% lo cual hace nuestro proyecto un negocio rentable. / The present project is based on the production and commercialization of natural and biodegradable fertilizer, which serves as a bio-stimulant for ornamental plants, with the additional value of being a water retainer for 20-21 days by applying the product once. Made with orange and avocado peel, our business is aimed at inhabitants of Modern Lima corresponding to conservative, modern and sophisticated lifestyles that have plants and / or small gardens belonging to socioeconomic levels (NSE) A, B and C, in addition to showing concern for the environment. The product packaging is going to be a biodegradable kraft paper bag with a capacity of 250 grams. A total of interviews were conducted with 30 people to validate the existence of the problem encountered and the interest and intention of using the product of our potential customers. In addition, in order to make this project scalable for the field of agriculture, two agronomy experts were contacted to validate the product and some aspects of its possible scalability. The development of the project is divided into two points, which are the validation of the business plan and development of the business plan. For the execution of the project, an investment of 21,454 soles was required, obtained based on the shareholders' own capital, who consider recovering said investment in the first year of operation. The profitability provided to shareholders is 249% which makes our project a profitable business. / Trabajo de investigación
39

The Effect of Gender and Narcotic or Stimulant Abuse on Drug-Related Locus of Control

Travis, Yolanda Rene 01 January 2018 (has links)
Substance use disorders cause significant neurological damage, cognitive impairment, and maladaptive behaviors that negatively affect a person's quality of life. The purpose of this study was to explore the effect gender and primary drugs have on locus of control. Generalized expectancy theory helped to explain the behavior of patients diagnosed with substance use disorders and their inability to control ongoing drug use. The research question focused on to what extent drug-related locus of control scores differ by primary drug (narcotic vs. stimulant), gender (male vs. female), and their interaction. Data measuring locus of control from 553 participants provided a subset of 410 participants who identified narcotics or stimulants as their primary drug. A 2x2 full factorial ANOVA was conducted. The results of this study indicated there is a significant interaction between primary drug use and gender. The results could have positive social change implications for the addiction field because of the value of understanding the interdependency of internal-external thought processes related to drug use, the ability to change stigma associated with addiction and gender, and the value of understanding the need for individualized treatment as locus of control shifts from external to internal. It is recommended that the drug-related locus of control instrument become part of treatment protocol along with evidence-based interventions.
40

Investigating Novel Approaches for the Integrated Control of the Soilborne Strawberry Pathogens Macrophomina phaseolina and Fusarium oxysporum f. sp. fragariae

Carter, Mel 01 June 2016 (has links) (PDF)
Macrophomina phaseolina (Mp) and Fusarium oxysporum f. sp. fragariae (Fof) are emerging soilborne pathogens causing crown rot and Fusarium wilt, respectively, in commercial strawberry production in California. Fungicides representing eight active ingredients from four different mode of action groups (FRAC groups 1, 3, 7 and 12) were evaluated for their efficacy against each pathogen in vitro and each disease in planta. Fungicide active ingredients were evaluated for their ability to inhibit mycelial growth of both pathogens in vitro. Half-strength potato dextrose agar was amended with six different concentrations (0.01, 0.1, 1.0, 5.0, 10, 50 µg a.i./ml) of seven fungicides in FRAC groups 3, 7 and 12. Concentrations that inhibited fungal growth by 75% (EC75) compared to unamended media were determined for two different isolates each of Mp and Fof and were used to determine fungicide rates for subsequent in planta studies. Tebuconazole strongly inhibited the mycelial growth of both pathogens (average EC75 for Mp was 2.4 ppm; average EC75 for Fof was 7.48 ppm), as did metconazole (average EC75 for Mp was2.53 ppm; average EC75 for Fof was 1.28 ppm). Fludioxonil strongly inhibited mycelial growth of Mp, but had no impact on the growth of Fof. Penthiopyrad, fluopyram, flutriafol, and flutolanil were less effective at inhibiting fungal growth of either fungus. Greenhouse in planta studies evaluated twenty-four fungicide treatments (eight fungicides at low, med and high rates) that were drench applied to infested potting media two days prior to planting of pathogen susceptible strawberry cultivars (San Andreas for Mp and Monterey for Fof) and again at day 21. Controls were a non-inoculated and an inoculated water-drench treatment. Buried inoculum was recovered at days 2 and 23 and plated on selective media for colony forming unit (CFU) quantification. Plant disease assessments were made each week for 11 weeks. An analysis of variance (ANOVA) of CFUs revealed no significant differences (p > 0.05) among treatments and when compared to the non-treated control for both Mp and Fof, but showed significant decreases (p < 0.05) in CFUs between weeks 1 and 3 for both Mp and Fof. An ANOVA for disease assessments in the form of area under the disease progress curve (AUDPC) showed significant decreases of disease severity in treatments with penthiopyrad only (low, medium and high rates) (p < 0.05). There were no significant differences (p > 0.05) in AUDPC among treatments and when compared to the non-inoculated and no-fungicide controls for Fof. The data indicates that these fungicides used alone are not effective against these pathogens in planta. A strawberry plant extract (germination stimulant) was assessed for its ability to stimulate germination of Mp microsclerotia in vitro and in planta. The germination stimulant was applied as a drench at six different concentrations (0, 10, 100, 1,000, 10,000 and 30,000 ppm) to soil containing filter disk packets of microsclerotia of Mp at day 0 and 14. Filter disk packets were retrieved three days after the drench and microsclerotia were observed microscopically for germination. Results showed that the number of germinating microsclerotia was significantly higher after the application of the germination stimulant compared to non-drench and 0 ppm controls (p < 0.001). An integrated container trial was also conducted using the germination stimulant at 10,000 ppm applied three days prior to a fungicide drench with tebuconazole or thiophanate-methyl to determine the effect of fungicides on the germinated microscleotia. The use of the germination stimulant with label rates of the fungicides lowered the number of germinated intact microsclerotia significantly (p < 0.001) especially after two drench applications. The use of the germination stimulant with fungicides could be investigated further as one method for controlling soilborne diseases of strawberry.

Page generated in 0.1237 seconds