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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

Investigação da influência de fatores ambientais na presença, densidade e distribuição espacial de culicídeos vetores, na zona oeste da capital, São Paulo / Investigation of the influence of environmental factors on the presence, density and spatial distribution of culicids vectors, in the western zone of the capital, São Paulo

Morgana Michele Cavalcanti de Souza Leal Diniz 26 June 2018 (has links)
Introdução: Várias espécies de culicídeos são vetores de patógenos que causam graves doenças em humanos e outros animais. Objetivos: Investigar a presença e distribuição espacial de insetos vetores na Cidade Universitária, zona Oeste - São Paulo e os fatores ambientais associados a sua ocorrência. Metodologia: A área de estudo foi a Cidade Universitária Armando de Salles Oliveira (CUASO), que foi dividido em quatro partes. As coletas com ovitrampas e adultraps foram realizadas de dezembro de 2013 a novembro de 2014, mensalmente foram sorteados dez pontos de coleta por área, em cada área foram instaladas dez ovitrampas e dez adultraps. As coletas com aspirador ocorreram de janeiro a dezembro de 2014 e mensalmente foram sorteados dois pontos por área para realização das aspirações, totalizando oito pontos de coletas por mês, resultando em 120 minutos/mensal. Todo material coletado foi levado ao Laboratório de Entomologia em Saúde Pública da Faculdade de Saúde Pública da USP para análise. Resultados: De maneira geral as variáveis ambientais influenciaram na presença dos culicídeos coletados. O índice de densidade de ovos sofreu influência significativa da temperatura, enquanto que a pluviosidade afetou mais significativamente a presença do adulto. Em relação à aspiração Culex quinquefasciatus foi a espécie predominante em todas as coletas, seguida de Aedes albopictus e Aedes aegypti. Porém apenas Aedes albopictus e Aedes aegypti apresentaram correlação significativa com as variáveis climáticas. Conclusão: a presença de culicídeos vetores na Cidade universitária foi expressiva praticamente o ano inteiro, tornando esse local um meio propício para propagação de várias arboviroses, necessitando um monitoramento constante da presença desses vetores. / Introduction: Several species of culicidae are vectors of pathogens that cause serious diseases in humans and other animals. Objectives: To investigate the presence and spatial distribution of vector insects in Cidade Universitária, Oeste - São Paulo and the environmental factors associated with its ocurrence. Methodology: The study area was the University City Armando de Salles Oliveira (CUASO), which was divided into four parts. The collections with ovitraps and adultraps were carried out from December 2013 to November 2014, monthly there were drawn ten collection points per area, in each area were installed ten ovitraps and ten adultraps. The collections with eletric aspirators (12V battery) occurred from January to December 2014 and monthly there were drawn two points per area to make the aspirations, totaling eight collection points per month, resulting in 120 minutes / month. All collected material was taken to the Laboratory of Entomology in Public Health of the Faculty of Public Health of USP for analysis. Results: In general the environmental variables influenced the presence of culicids collected. The egg density index was significantly influenced by temperature, while rainfall affected the adult presence more significantly. Regarding aspiration Culex quinquefasciatus was the predominant species in all collections, followed by Aedes albopictus and Aedes aegypti. However, only Aedes albopictus and Aedes aegypti showed a significant correlation with climatic variables. Conclusion: the presence of culicids insects in the University City was expressive practically all year round, making this place a propitious medium for the propagation of several arboviruses, necessitating a constant monitoring of the presence of these vectors.
42

Assessing the Effects of Myxobolus cerebralis and Other Environmental Factors on the Dynamics, Abundance, and Distribution of Trout Populations in the Logan River, Utah

de la Hoz Franco, Ernesto A. 01 May 2003 (has links)
The presence of nonnative trout and the recent introduction of Myxobolus cerebralis in the Logan River drainage pose a threat to the native Bonneville cutthroat trout population (Oncorhynchus clarki Utah). The variability in the response of susceptible trout populations to M. cerebralis, causing agent of whirling disease, suggests that environmental factors may influence the effects of the parasite in infected environments. I investigated the relationship between temperature, discharge, substrate size, nutrient concentration (nitrogen and phosphorus), periphyton (chlorophyll a), and the relative abundance of Tubifex tubifex to the distribution, and prevalence of M. cerebralis in wild salmonid populations and sentinel fish in the mainstem of the Logan River and two of its tributaries. In addition, I investigated the potential influence of biotic (e.g., food availability, M. cerebralis prevalence) and abiotic factors (e.g., temperature) on the distribution abundance, and condition of salmonid fishes. Differences in mean temperature and discharge across sites explained most (>70%) of the variability in prevalence of M. cerebralis observed along the Logan River. However, the prevalence of the parasite was not related to other factors that can influence its life cycle, such as productivity and substrate composition. The results also indicate that the fish fauna presents a longitudinal change reflected in a zonation pattern. Cutthroat trout dominates the headwaters and high-elevation reaches, while reaches at lower elevations of the mainstem and tributaries were dominated by brown trout. The transition between these species was consistent with changes in environmental characteristics. Cutthroat trout dominates the fish community in mainstream reaches with the lowest average minimum temperature and highest diel temperatures, and where small boulders and small cobbles are the predominant substrate. This study provides insights of the abiotic and biotic factors that affect the distribution, abundance, and condition of salmonid populations along the Logan River. Identifying these factors is crucial to effectively manage this and other trout streams, where ensuring the conservation of native cutthroat trout populations is a priority. Further, I present baseline information of the potential linkages between environmental factors and M. cerebralis distribution and prevelance, which could be used to develop plans to minimize the potential negative effects of this parasite on wild salmonid populations.
43

Relationship of Certain Environmental Factors to Benthic Fish Densities in Bear Lake, Idaho-Utah

Hassler, Thomas J. 01 May 1960 (has links)
The project was initiated in June of 1958 and financed by the National Science Foundation and the Wildlife Management Department of Utah State University. The broad aspects of the study were to determine if a relationship exists between certain physical and biological factors and benthic fish densities. The project vas divided into two parts: (l) to determine the time and extent of thermal stratification, zooplankton densities, conductivity changes within the lake and conductivity differences between the lake and its tributaries; (2) to determine it a relationship exist between benthic fish densities, temperatures, depths, conductivities and benthic zooplankton densities. The data were analyzed statistically and a separate regression analysis was run on each factor to determine the degree of relationship between that factor and benthic fish densities.
44

A Study of Foliar Absorption of Urea in Peach and Apple Trees Influenced by Plant and Environmental Factors

Yazdaniha, Ataollah 01 May 1969 (has links)
Studies were conducted under greenhouse conditions to investigate the relative efficiency of urea absorption by 1-month-old peach and apple leaves. A 4 percent solution of urea containing .1 percent Colloidal X-77 was applied to the leaves in the form of a fine spray. To aid in this procedure, an improved micros prayer with a l milliliter capacity was developed. Accuracy of the sprayer was ± l percent. Under greenhouse conditions, the upper and lower surface of peach and apple leaves absorbed urea. More urea was absorbed through the lower than the upper surface. Peach lower surface absorbed nearly as much as apples after 48 hours. In another experiment using a controlled environmental growth chamber, the effect of temperature, humidity and surfactant (Colloidal X-77) on absorption of 1 percent 14C urea solution by apple and peach leaves were studied. Uptake was again much greater from the lower surface of the leaves as compared to the upper surface. Low relative humidity (25 percent) reduced absorption substantially. High temperature (24 centigrade) under low humidity (25 percent) decreased absorption. Uptake was increased substantially with the high temperature (24 centigrade) and relative humidity (85 percent). Peach leaves were more sensitive to temperature than apple, in regard to the amount of absorption that occurred. In peach, a 5 to 10 fold decrease in absorption was observed when the temperature was lowered from 24 to 10 centigrade. Surfactant increased absorption through the lower surface within a short period after application but decreased it afterwards. Urea absorption through 45-day-old leaves at 85 percent relative humidity and 24 centigrade indicated that within 48 hours over 90 percent of the urea applied to lower surfaces was absorbed by both species of leaves. A cuticular permeability experiment indicated that upper cuticles from both species of leaves were permeable to urea. It seemed that permeability of peach cuticle increased with time at the higher temperature. After 48 hours, the amount of urea, which penetrated through the peach cuticle at 24 centigrade, was 2.7 fold as much as at 10 centigrade. Urea absorption within 1 hour and translocation after 4 hours were observed under favorable conditions (24 centigrade and 85 percent relative humidity). Radioautograms of 14C urea treated apple and peach leaves indicated that the 14C urea and/ or its metabolites had been translocated within a large portion of the leaf within 8 hours after application. Studies were also performed on these species utilizing microradioautography and histochemistry techniques. Microradioautograms prepared from treated leaf sections demonstrated that adsorption and absorption of radioactive urea occurred on the epidermal hairs of apple leaves. Urea entry occurred in both apple and peach leaves as evidenced by high activity of 14C compounds within the leaf tissue. Microscopic observations of freshly sectioned leaves of both apple and peach demonstrated a relatively high amount of pectinaceous substances between the cell walls and especially the bundle sheath and bundle-sheath extension cells. Pectinaceous substances were present more in apple cuticle than in peach cuticle.
45

Weight Maintenance: Determinants Of Success

Mitchell, Cynthia 01 May 2005 (has links)
This literature review was a selective examination of current obesity and physical activity research and opinions. Its purpose was more to evoke thought and discussion regarding the United States' obesity epidemic, rather than serve as an exhaustive account of prospective causes and solutions. Obesity and physical inactivity are major preventable health problems in the United States, but despite overwhelming evidence regarding the benefits of a healthy weight and regular physical activity, adult, childhood and adolescent obesity rates continue to escalate, creating significant health, medical and economic consequences. While obesity rates soar, a small population percentage has proven successful in long-term weight maintenance, even in the presence of significantly influential environmental and interpersonal factors. Reviewing strategies employed by National Weight Control Registry members, this literature review discusses the two behavioral components missing from standard or traditional, action-oriented intervention programs. Although th e Stages-of-Change Model ex plains an indi vidual"s readiness to change and the process in vo lved, se lf-effi cacy and self-regulating behav iors were shown to have a more positi ve effect on long-term maintenance. Thus, recommendati ons for practical appli cation include incorporating these behavioral components for a more effecti ve and client-centered interventi on program.
46

Modelling spatial and temporal species distribution in the Baltic Sea phytobenthic zone

Nyström Sandman, Antonia January 2011 (has links)
Statistical modelling is often used to relate the presence or abundance of species to environmental predictors, thereby providing a basis for predictive mapping of species or biodiversity. The variables included must thus be relevant and reflect actual changes in the environment. Therefore, the quantification of species–environment relationships is an important aspect of predictive modelling. This thesis examines how phytobenthic species or communities in the Baltic Sea relate to environmental gradients, and if different aspects of phytobenthic species distribution in the Baltic Sea could be explained by spatial or temporal variation in environmental factors. Predictive distribution modelling usually focuses on how environmental variables control the distribution of species or communities. Thus the relative weight of the predictor variables on different scales is of importance. In this thesis, I show that the relative importance of environmental variables depends both on geographic scale and location, and that it also differs between species or species groups. There are no simple explanations to the temporal variability in species occurrence. I here show that the temporal changes in species distribution within the phytobentic zone varies in a spatial context. I also try to find temporal and spatio-temporal patterns in species distribution that could be related to changes in climate or anthropogenic disturbance. However, the findings in this thesis suggest that single factor explanations are insufficient for explaining large-scale changes in species distribution. A greater understanding of the relationship between species and their environment will lead to the development of more sensitive models of species distributions. The predictions can be used to visualise spatial changes in the distribution of plant and animal communities over time. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.
47

Evaluation of a Body Pillow to Aid Pediatric Spinal Fusion Recovery

Joffe, Naomi Eve 14 August 2009 (has links)
Spinal fusion is a surgical procedure used to correct structural spinal damage or abnormalities. Recovery is painful and consists of a minimum 3-day hospital stay. Specific body positioning is necessary for healing but is difficult to maintain due to physical discomfort. The purpose of this study was to use a single-subject multiple baseline design to compare the current practice of using standard hospital pillows to a body-sized pillow for increasing comfort and decreasing pain in pediatric patients recovering from spinal fusion surgery. Four adolescents who had recently undergone spinal fusion surgery served as participants. Outcome measures included self- and nurse-report, heart rate, and requested medication. Three patients found that the BodyPillow® increased their comfort as they recovered from surgery; the fourth reported that he was less comfortable. No changes in pain were reported with the BodyPillow®. Results should help guide medical care and future research regarding pediatric spinal fusion recovery.
48

Omvärlden påverkar : En studie av hur revisionsbyråernas marknadsföring har påverkats av den avskaffade revisionsplikten för mindre och medelstora företag.

Haddad, Reine, Mattsson, Louise January 2012 (has links)
Titel: Omvärlden påverkar: En studie av hur revisionsbyråernas marknadsföring har påverkats av den avskaffade revisionsplikten för mindre och medelstora företag. Nivå: Kandidatuppsats i företagsekonomi; Marknadsföring Författare: Reine Haddad och Louise Mattsson Handledare: Jonas Kågström Datum: 2012- Juni Syfte: Med uppsatsen vill vi undersöka om revisionsbyråernas marknadsföring förändrats i samband med att revisionsplikten för mindre bolag avskaffats, det vill säga om marknadsföringen påverkas av omvärldsfaktorer. Metod: I studien används en abduktiv ansats där information samlats in dels via Internet (WayBack Machine) och dels genom att ta del av annonser från en revisionsbyrå. För att tydliggöra materialet sammanställdes det i frekvenstabeller, wordles och diagram. Resultat & Slutsats: I enlighet med vad den valda teorin framställer ser vi att även revisionsbyråerna ändrar delar av sin marknadsföring när förändringar i omvärlden sker. Omfattningen av förändringarnas påverkan på marknadsföringen varierar från revisionsbyrå till revisionsbyrå, bland annat beroende på revisionsbyråernas syn på marknadsföring, hur stora förändringarna i omvärlden är och hur snabbt revisionsbyråerna tar till sig dessa förändringar. Uppsatsens bidrag: Vårt examensarbete har bidragit med att ge en bild av hur revisionsbyråernas marknadsföring påverkas av förändringar i omvärldsfaktorer. Detta kan vara användbart då marknadsföraren måste ta dessa omvärldsfaktorer i akt vid planering och utformning av marknadsföringen. Nyckelord: Revisionsplikt, revisionsbyrå, marknadsföring, påverkan och omvärldsfaktorer. / Title: The influences of the environment: A study of how the marketing of the auditing firms has been affected by the abolishing of the mandatory auditing for smaller companies. Level: Final assignment for Bachelor Degree in Business Administration Authors: Reine Haddad and Louise Mattsson Supervisor: Jonas KågströmDate: 2012 – June Aim: Our aim with this thesis is to investigate if the marketing of the auditing firms has changed as a result of the abolishing of the mandatory auditing for smaller companies. Method: In this study we are using an abductive approach where information has been gathered partly through the Internet (WayBack Machine) and partly through advertisements from PwC, an auditing firm. The results of the study are put together in frequency tables, wordles and diagrams. Result & Conclusion: We can, according to the theoretical representation, draw the conclusion that the auditing firms are changing parts of their marketing due to changes in the environment. The dimension of the changes on the marketing fluctuates from auditing firm to auditing firm, depending on, for example, the size of the changes in the environment, how quick the auditing firms are adjusting to these changes and the auditing firm’s vision of marketing. Contribution of thesis: The contribution of our thesis is to illustrate how the marketing of the auditing firms are changing due to environmental factors. This can be useful when the marketer have to consider these environmental factors when planning and designing the marketing activities. Keywords: Mandatory auditing, auditing firm, marketing, influence and environmental factors.
49

"Jag kan inte sova!" : -miljöfaktorer som kan påverka patienters sömn på sjukhus / "I can´t sleep!" : environmental factors that may affect the patient's sleep in the hospital

Carlström, Michelle, Christensson, Hanna, Johansson, Åsa January 2011 (has links)
Det är sedan länge känt att sömn på sjukhus är ett viktigt grundläggande behov för tillfrisknad. Det finns en bristande uppmärksamhet från sjukvårdpersonal om sömnproblematiken som finns på sjukhus, och miljöfaktorer som kan påverka patienters sömn negativt. Dessa faktorer kan förbättras om problemen identifieras och åtgärder vidtas för att förbättra sömnmiljön. Syftet med studien var att belysa miljöfaktorer som kan påverka patienters sömn på sjukhus. Studien är genomförd som en litteraturstudie där 21 vetenskapliga artiklar samlades in och granskades. Resultatet visade att de främsta miljöfaktorer som störde patienters sömn var ljud, ljus och temperatur. Hälften av allt ljud som störde patienters sömn orsakades av sjuksköterskorna. Ljuset var ofta mycket starkt på sjukhus, och under natten var ljuset fortfarande för starkt för att främja sömn. Behaglig rumstemperatur för god sömn var individuell och handlade delvis om vad patienten var van vid från hemmet. Genom att få kunskap om de olika miljöfaktorer som stör patienters sömn, kan åtgärder vidtas som minskar vårdtiden och resulterar i en välmående patient. / The sleep at the hospital is an important factor for the patient in order to recover. There is a lack of attention from health care professionals about sleeping problems that exist in the hospital. There are environmental factors that affect patients sleep negatively in the hospital. These factors can be improved if the problem identifies and care measures are taken. The aim of the study was to illuminate the environmental factors that may affect the patient's sleep in the hospital. The study was operating as a literature study where 21 scientific articles were collected and examined. The result of the study showed that the main environmental factors that interfered patients sleep was sound, light and temperature. Half of all the noise at the hospital was caused by nurses. The light was often very strong in the hospital, during the night the light was still strong to promote sleep. The temperature within the sleeping area was individual and is partly reflecting what patients are used to from home. By gaining knowledge about environmental factors that can interrupt the patient during sleep in the hospital, interventions can be taken to shorten the length of the stay and the patient can recover faster.
50

Genetic and Environmental Contributions to Baseline Cognitive Ability and Cognitive Response to Topiramate

Cirulli, Elizabeth Trilby January 2010 (has links)
<p>Although much research has focused on cognitive ability and the genetic and environmental factors that might influence it, this aspect of human nature is still far from being well understood. It has been well-established that certain factors such as age and education have significant impacts on performance on most cognitive tests, but the effects of variables such as cognitive pastimes and strategies used during testing have generally not been assessed. Additionally, no genetic variant has yet been unequivocally shown to influence the normal variation in cognitive ability of healthy individuals. Candidate gene studies of cognition have produced conflicting results that have not been replicable, and genome-wide association studies have not found common variants with large influences on this trait.</p><p>Here, we have recruited a large cohort of healthy volunteers (n=1,887) and administered a brief cognitive battery utilizing diverse, common, and well-known tests. In addition to providing standard demographic information, the subjects also filled out a questionnaire that was designed to assess novel factors such as whether they had seen the test before, in what cognitive pastimes they participated, and what strategies they had used during testing. Linear regression models were built to assess the effects of these variables on the test scores. I found that the addition of novel covariates to standard ones increased the percent of the variation in test score that was explained for all tests; for some tests, the increase was as high as 70%.</p><p>Next, I examined the effects of genetic variants on test scores. I first performed a genome-wide association study using the Illumina HumanHap 550 and 610 chips. These chips are designed to directly genotype or tag the vast majority of the common variants in the genome. Despite having 80% power to detect a common variant explaining at least 3-6% (depending on the test) of the variation in the trait, I did not find any genetic variants that were significantly associated after correction for multiple testing. This is in line with the general findings from GWA studies that single common variants have a limited impact on complex traits.</p><p>Because of the recent technological advances in next-generation sequencing and the apparently limited role of very common variants, many human geneticists are making a transition from genome-wide association study to whole-genome and whole-exome sequencing, which allow for the identification of rarer variants. Because these methods are currently costly, it is important to utilize study designs that have the best chance of finding causal variants in a small sample size. One such method is the extreme-trait design, where individuals from one or both ends of a trait distribution are sequenced and variants that are enriched in the group(s) are identified. Here, I have sequenced the exomes of 20 young individuals of European ethnicity: 10 that performed at the top of the distribution for the cognitive battery and 10 that performed at the bottom. I identified rare genetic variants that were enriched in one extreme group as compared to the other and performed follow-up genotyping of the best candidate variant that emerged from this analysis. Unfortunately, this variant was not found to be associated in a larger sample of individuals. This pilot study indicates that a larger sample size will be needed to identify variants enriched in cognition extremes.</p><p>Finally, I assessed the effect of topiramate, an antiepileptic drug that causes marked side effects in certain cognitive areas in certain individuals, on some of the healthy volunteers (n=158) by giving them a 100 mg dose and then administering the cognitive test two hours later. I compared their scores at this testing session to those at the previous session and calculated the overall level to which they were affected by topiramate. I found that the topiramate blood levels, which were highly dependent on weight and the time from dosing to testing, varied widely between individuals after this acute dose, and that this variation explained 35% of the variability in topiramate response. A genome-wide association study of the remaining variability in topiramate response did not identify a genome-wide significant association.</p><p>In sum, I studied the contributions of both environmental and genetic variables to cognitive ability and cognitive response to topiramate. I found that I could identify environmental variables explaining large proportions of the variation in these traits, but that I could not identify genetic variants that influenced the traits. My analysis of genetic variants was for the most part restricted to the very common ones found on genotyping chips, and this and other studies have generally found that single common genetic variants do not have large affects on complex traits. As we move forward into studies that involve the sequencing of whole exomes and genomes, genetic variants with large effects on these complex traits may finally be found.</p> / Dissertation

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