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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.
11

The Seasonality of Eosinophilic Esophagitis Flares in Children and Adolescents in Arizona

Manley, Kelsi 11 May 2017 (has links)
A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Aeroallergens are implicated in the pathogenesis of eosinophilic esophagitis, which has a recurrent or relapsing nature. We aim to determine the incidence of seasonal disease recurrence, referred to as flares, of eosinophilic esophagitis in patients in Arizona with eosinophilic esophagitis in remission, and to characterize the presence of allergy and other disease co‐morbidities in patients that experience disease flare. A retrospective study was performed by analyzing data from visits of patients aged 5 to 18 years coded for eosinophilic esophagitis in remission seen by the Phoenix Children’s Hospital Pediatric Gastroenterology Department between June 2010 and June 2011. The data included 148 patients and 326 clinical visits. Data identified demographic information, allergy, and other disease co‐morbidities. Arizona seasons were defined as: spring from February 15 to June 15, and fall from September 1 to November 30, according to the typical pattern of allergen pollination. To analyze incidence and season of flares, statistical methods used included the Chi‐square tests and logistic regressions. Ninety‐four of 148 patients (63.5%) flared during the study period. An increased incidence of flares in the fall compared with other seasons was statistically significant (p = 0.041). Flares in the spring also had an increased incidence. Of the 94 patients that flared, 70 patients (74.5%) had environmental allergy, 83 (88.3%) had food allergy, and 66 (70.2%) had both environmental and food allergy. Our findings suggest a role for seasonal environmental allergens in the pathogenesis of eosinophilic esophagitis and disease flares in children in Arizona, particularly those with food allergy, environmental allergy, or both.
12

Sazonalidade e as redes de interações planta-polinizador

Genini, Julieta [UNESP] 31 August 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-31Bitstream added on 2014-06-13T21:01:46Z : No. of bitstreams: 1 genini_j_dr_rcla_parcial.pdf: 434949 bytes, checksum: 6d17f9cb2c5d6677db2aa97d780fe759 (MD5) Bitstreams deleted on 2014-11-14T12:17:00Z: genini_j_dr_rcla_parcial.pdf,Bitstream added on 2014-11-14T12:17:46Z : No. of bitstreams: 1 000673076.pdf: 2180690 bytes, checksum: 4a09ca8eef33ba14265d1b718f224d03 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Os padrões de floração no nível de comunidade podem afetar a dinâmica dos sistemas ecológicos. Dessa formam a caracterização dos modos de polinização e padrões de floração no nível de comunidade são fundamentais para entender a variação sazonal das flores, polinizadores e sua organização temporal nas diferentes vegetações. Portanto, nos examinamos a floração no nível de comunidade e procuramos identificar padrões agregados, segregados e temporalmente aninhados na Reserva Municipal de Santa Genebra (SGR), uma floresta semidecídua do Sudeste de Brasil. Depois, nós avaliamos os padrões de floração, a diversidade e organização temporal por modos de polinização em SGR. Posteriormente, nos concentramos na dinâmica temporal de uma pequena rede de visitantes florais. Finalmente, estudamos outras dois redes de visitantes florais e avaliamos como diferentes tipos de enlaces (i.e. pilhadores e polinizadores efetivos) afetam a estrutura das redes. Nós encontramos que os padrões de floração em SGR são agregados e aninhados, e identificamos as causas do aninhamento temporal quando removemos as espécies de floração longa. Alem do mais, a SGR apresentou uma alta diversidade de modos de polinização, comparável a outras florestas tropicais, e essa diversidade encontra se representada ao longo das diferentes estações desde que o clima e a filogenia não restringiram a floração da maior parte das espécies. Nos encontramos uma alta dinâmica temporal na nossa pequena rede de visitantes florais junto a um importante componente especial de algumas interações. Por ultimo, a remoção... / Flowering patterns are likely to affect ecological dynamics of plant communities. In that sense, characterization of pollination modes and its flowering patterns at a community level are fundamental to understand the seasonal variation of flowers, pollinators and their temporal organization in different vegetations. Therefore, we examine the flowering patterns at a community level and explored aggregation, segregation and temporal nestedness at the Santa Genebra Reserve, (SGR), a semideciduous forest of Southeastern Brazil. Then, we also evaluate the flowering patterns, diversity and temporal organization of pollination modes within the SGR. Subsequently, we focus on the temporal dynamic of a small sphyngophylous flower visitation network. At last, we studied two other flower visitation networks – Malpighiaceae and Bignoniaceae - and evaluated how different types of links (i.e. cheaters and effective pollinators) influence network topology. We found that the flowering pattern of the SGR community is aggregated and nested. We also identified the causes of nestedness in this community by removing the long-lasting flowering plants. In addition, SGR forest present a high diversity of pollination modes, comparable to other tropical systems, and this diversity is represented across the seasons, since climate and phylogeny did not restrict the flowering of most plants regardless the pollination mode. We also find a high temporal dynamic in our small visitation network as well as a spatial component of some links. Finally, the removal of a particular type of links (cheaters) in one of the visitation networks (Bignoniaceae) completely changed the structure of the network. To conclude, even when the community... (Complete abstract click electronic access below)
13

Changes in Gene Expression of Goat Developing Testes and Sperm During Breeding and Non-breeding Season

Faucette, Azure 2012 May 1900 (has links)
Testicular function is fundamental to male fertility, since testicular cells act in collaboration with each other to signal sex differentiation, the initiation of puberty and spermatogenesis. Complications that can be influenced by many factors will affect sperm number, morphology, motility, chromatin quality and acrosomal integrity. The purpose of these studies was to analyze the changes in gene expression in the developing testes and analyze the seasonal changes in gene products in sperm of mature bucks. In the first experiment, testes were harvested from five Alpine bucks at 0, 2, 4, 6, and 8 months of age. Northern and in situ hybridization indicated that the largest change in gene expression occurred during the first 4 months of goat testes development. Sex determining region Y-box 9 (SOX9) and Heat Shock protein A8 (HSPA8) peaked at 2 months of age, and were expressed in Sertoli cells and spermatogonium, respectively. At 4 months, expression of Stimulated by Retinoic Acid gene 8 (STRA8), Protamine1 (PRM1) and Outer Dense Fiber protein 2 (ODF2) was strongly up-regulated in early and maturing germ cells, respectively. In the second experiment, RNA from ejaculated spermatozoa collected from mature Alpine bucks in peak (October) and non-peak (April) breeding season were analyzed on a 4 x 44K Agilent bovine microarray. One thousand three hundred and eighteen gene products were differentially expressed 2-fold or more (p ≤ 0.05 ) was expressed in mature goat sperm collected October and April. To eliminate the likelihood of false positives, the cut off was set to fold change of 3 or more at p ≤ 0.01 which narrowed the list of genes to 50 transcripts. Real time PCR results confirmed the expression of Sperm Adhesion Molecule 1 (SPAM1) in April, and the expression of Glycerol kinase 2(GK2) and Myc Binding Protein 2 (MYCBP2) in October. Based on the results from both experiments, it can be concluded that: SOX9 and HSPA8 expression play an important role in tubular formation and germ cell maintenance; two months after SOX9 and HSPA8 expression, genes that are associated with spermatogenesis initiation and completion are upregulated; and validation of the seasonal changes in sperm mRNA levels may provide additional insight to testicular events as they relate to breeding and non-breeding season.
14

Timing of Larval Release by Five Coral Species in Southern Taiwan¡GSeasonality, Lunar and Diurnal Periodicity

Lin, Ke-han 10 August 2005 (has links)
The seasonality, lunar and diurnal periodicity of planulation of five scleractinian corals, Seriatopora hystrix, Stylophora pistillata, Pocillopora damicornis, Euphyllia glabrescens and Tubastraea aurea, were compared. Corals were collected monthly and maintained in outdoor, flow-through systems to quantify the number of larvae released. Planulation of the five species occurred throughout the year. The long period of reproduction may be related to the warm mean seawater temperature in Nanwan Bay. S. pistillata released few larvae during late summer and early fall, suggesting the seasonality of reproduction. The pattern of lunar cycle can be classified into three strategies: (1) Planulation of S. hystrix and P. damicornis showed clear lunar periodicity and the peak of larval release shifted with different months. The peak of planulation occurred around the full moon in winter then shifted gradually to the first quarter moon phase in summer. The phase shift of larval release may be related to the seasonal variation of seawater temperature and the sudden temperature drops caused by upwelling. (2) Planulation of S. pistillata showed clear lunar periodicity and the peak of larval release occurred around the full moon. This may promote the larval dispersal. (3) E. glabrescens and T. aurea showed clearly lunar periodicity and the peak of larval release changed with different months. The peak of planulation shifted from full moon to new moon during winter and spring while it shifted from new moon to full moon during summer and fall. The pattern of diurnal cycle also can be classified into three strategies: (1) Planulation of S. hystrix and S. pistillata revealed a well-defined diurnal pattern with most planulae being released close to sunrise. (2) P. damicornis and E. glabrescens released larvae throughout the day, with two peaks occurring in the early morning and in the night. Corals of all three pocilloporids and E. glabrescens timed larvae release relative to the light-dark cycle suggesting that diurnal cycle determined when larvae were released. Larvae released in the dark may have lower risk of predation effect. Furthermore, the peak planulation occurred close to sunrise may be advantageous for some mature larvae to have light cues for quick settlement within the natal reef. (3) The azooxanthellate coral T. aurea released larvae throughout the day with no apparent cycle. These results suggest that zooxanthellae may play a role in regulating the diurnal cycle.
15

Intra-annual variability in standards of water and sanitation in Upper Humla, Nepal : an investigation into the causes, importance and impact

Greene, Nicola January 2014 (has links)
This study investigates the impact of seasonality on standards of water and sanitation in the mountainous district of Humla, Nepal. The research considers impact on two levels: community level access and service delivery. First of all, it examines annual variation in village level access to water and sanitation. Secondly, it looks at the wider picture of service delivery and considers how seasonal variations present opportunities and challenges for improvement in standards for water and sanitation. Three case studies from Humla are presented which illustrate village level access to water and sanitation over a calendar year. These case studies summarise the content of 45 semi-structured interviews, 9 focus group discussions and 9 months of observational work in the district. Variations in weather, village population, infrastructure functionality, and environmental conditions are found to influence the experienced levels of access to water and sanitation at any given time. The impact of seasonality on service delivery was investigated via 39 key informant interviews. Both climatic (e.g. weather) and non-climatic (e.g. budget timings) sources of seasonality are found to impact programme implementation. The mismatch of local seasonal calendars and those imposed by central hubs is found to cause particular difficultly in effective delivery of water and sanitation services. The findings of this research have theoretical, methodological and practical implications. Theoretically, it is suggested that a mountain community s level of access to water and sanitation varies considerably over the course of a calendar year to the point where it needs to be considered if on the ground standards are to be improved. Methodological guidance is provided detailing means of investigating seasonality and its impact on standards of water and sanitation in other scenarios. Practical suggestions focus on incorporating seasonality into assessments of access to water and sanitation and programme delivery in mountain communities.
16

Human ecological stress and menstrual function

Ikeme, Patience Obianuju January 1995 (has links)
No description available.
17

Climate Predictors of Global Influenza Seasonality in Temperate and Tropical Populations

Tamerius, James Derek January 2011 (has links)
The consistent seasonal signal that characterizes annual influenza epidemics has long suggested a causal link between the physical environment and the transmission of influenza. Yet, despite considerable interest--dating as far back as Hippocrates--the environmental factors that facilitate the seasonal spread of influenza remain unclear. Historically, significant study of influenza seasonality was based almost exclusively on temperate regions,.due to a lack of high-quality influenza data in low-latitudes. In turn, although numerous hypotheses have been forwarded to explain the seasonal nature of influenza in temperate regions, few acknowledge the seasonal patterns in lower latitudes.This dissertation examines the scientific evidence for the seasonal mechanisms that potentially explain the complex seasonal patterns of influenza disease activity across the latitudinal gradient extending from temperate to tropical regions. I identified seasonal climatic variables that are potentially responsible for influenza seasonality from observational, experimental, ecological and anecdotal studies. I then used a global database of influenza seasonality to assess the consistency of relationships between influenza seasonality and the seasonality of relevant climatic variables. I determined that no single climatic variable is consistently correlated with seasonal influenza activity across temperate, subtropical and tropical regions.However, I did find a significant U-shaped relationship between specific humidity and influenza epidemics globally with epidemics becoming increasingly likely as specific humidity increases or decreases from approximately 12 g/kg. Further, I examined the temporal and spatial variation of influenza activity and specific humidity during the 2009 A/H1N1 pandemic across Mexico, which spans temperate, subtropical and tropical regions. I show that specific humidity may have modified the progression of three distinct waves of infection during the pandemic. These patterns are in agreement with the U-shaped relationship between specific humidity and seasonal influenza epidemics observed at a global scale. In all, this is the first time that relationships between climate and influenza (both seasonal and pandemic) activity have been successfully synthesized into a single parsimonious model across temperate, subtropical and tropical regions.
18

Mangrove Shoreline Fish Assemblages of Oleta River State Park: Baseline Conditions in an Urban System

De Angelo, Jacquelyn Alexis 01 January 2010 (has links)
Oleta River State Park (ORSP), located in North Miami-Dade County is known as the most highly urbanized State Park in all of Florida. The present study was conducted as part of an ongoing seasonally-resolved survey of fish utilization of the mangrove shorelines of Biscayne Bay. Previous Unit Management Plans published by the Division of Recreation and Parks have lacked information concerning the park?s prominent mangrove forests along with its icthyofauna. The main purpose of this thesis was to provide a baseline characterization of the mangrove-fish assemblages and microhabitat trends of ORSP, against which future changes in and around the Park can be gauged. Fish assemblages inhabiting the mangrove shorelines were examined using a visual ?belt-transect? census method over 11 consecutive seasons. Microhabitat variables including salinity, water temperature, water depth, water clarity and distance from Baker?s Haulover Inlet were examined for possible correlations with fish metrics. Several significant differences were evident in the taxonomic richness (number of taxa per unit area) and densities of the five most abundant taxa within the shoreline habitats in terms of seasonal variation and microhabitat variable distribution along the river. Taxonomic richness was typically greater in survey sites located closer to Baker?s Haulover Inlet. Oleta River?s mangrove shoreline fish assemblages appear to reflect (1) proximity of the mangroves that they occupy to Baker?s Haulover Inlet; (2) temperature regime along the shoreline; and (3) the salinity gradient found within the river. Fish assemblage and microhabitat information collected here could serve as a ?baseline? in future investigations of the effects of further urbanization or the effects of other anthropogenic changes to Oleta River and its mangrove habitat, including possible changes to freshwater flow associated with the Comprehensive Everglades Restoration Plan.
19

Biological and Psychosocial Aspects of Postpartum Depression

Sylvén, Sara M January 2012 (has links)
Postpartum depression (PPD) is one of the most common complications of childbirth around the world. Despite several studies on the underlying mechanisms, the pathophysiology remains elusive. The aims of this thesis were to assess possible associations between the risk for self reported PPD and serum levels of leptin, the season of delivery, the gender of the newborn, and the history of premenstrual symptoms, respectively. A population based cohort of 2318 newly delivered women in Sweden were screened five days, six weeks and six months postpartum, using the Edinburgh Postnatal Depression Scale. This cohort comprised 60% of the total population, and the prevalence of self reported PPD was 11.1% six weeks after the delivery. A negative association between leptin levels at delivery and self reported PPD at six weeks and six months postpartum was evident, even after adjusting for confounding factors.  An increased risk for self reported PPD was noted among women delivering during the last three months of the year, compared to those giving birth in April through June. This is of clinical importance, since women delivering at the end of the year could benefit from a closer follow-up after delivery.  Despite previous varying findings – depending on study population and consequently different cultural settings – in our study, no association between infant gender and self reported PPD could be detected at six weeks or six months postpartum. However, women giving birth to baby boys had a higher risk for postpartum blues.   Lastly, an increased risk for self reported PPD among women with a history of premenstrual symptoms was noted. Interestingly, after stratification for parity, the association between PPD and premenstrual symptoms remained only among multiparas. The association between PPD and premenstrual symptoms might shed light on the many possible routes by which hormonal changes may influence mood in women. In conclusion, this population based study strengthens the notion that PPD is a complex multifactorial disorder, with biological, social and psychological parameters shaping each individual’s risk.  Further research is needed in this field, in order to investigate underlying pathophysiological mechanisms, propose more effective diagnostic tests and assess therapeutic interventions. / UPPSAT
20

Temporal Variation in Space and Resource Use of Macaws in the Southeastern Peruvian Amazon

Adamek, Krista Anne 2011 May 1900 (has links)
Space use and resource use of three species of macaws (Ara ararauna, A. chloropterus, and A. macao) were studied for a period of three years in the southeastern Peruvian Amazon. Basic information on wild macaw populations is lacking due to the logistical and behavioral challenges of working with these species in dense rainforest. Population declines world-wide have been attributed significantly to a reduction in food and nesting resources due to habitat loss. This research aims to obtain baseline data on macaws in a region with relatively intact rainforest. Specific objectives were to (1) quantify space use, describe the spatial and temporal variation in movement patterns, explore habitat selection and spatial pattern of resources during the non-breeding season, and (2) identify key nesting and foraging species and determine whether there is seasonal variation in diet, and explore how resources may be related to movements and competition. Individuals from each species were radio-tagged and monitored from 2004 to 2008 by ground, platform, and aerial tracking. Seasonal ranges were estimated using MCP and KDE methods. Diversity and niche measurements and selection were calculated for dietary items, nesting substrate, and habitat. The relationship between palm habitat distribution and A. ararauna movements was explored using landscape analysis techniques. All species had similar home range sizes during the breeding season, ranging from a mean of 1,540 ha to 2,541 ha. Non-breeding ranges were significantly larger for A. ararauna (117,849 ha). Greater than 200 species of plants were consumed, yet seasonal preferences vary. The increase in dietary breadth and decrease in overlap during dry season is unlikely related to food scarcity or competition. Key nesting and dietary species include Mauritia flexuosa, Dipterix micrantha, and Bertholletia excelsa. Palm habitat is a key resource for Ara ararauna and associated with long-distance movements. This research addresses a critical gap in our knowledge regarding macaw movements and resource use in Amazonian rainforest. Despite their mobility, their low fecundity and specialized nesting requirements can impact reproductive success and population growth if habitat loss continues on its current trajectory.

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