• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 191
  • 94
  • 32
  • 17
  • 9
  • 7
  • 6
  • 4
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 449
  • 130
  • 77
  • 62
  • 54
  • 49
  • 47
  • 47
  • 46
  • 41
  • 40
  • 38
  • 35
  • 34
  • 34
  • 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.
51

"A Different Perspective": Exploring the Influences of Religious Background and Family Upbringing in Mormon Women's Views of Marriage and Motherhood

Paul, Allison January 2014 (has links)
Thesis advisor: Gustavo Morello / This qualitative study aims to understand how Mormon religious practice and individual family upbringing shape faithful Mormon women’s goals for marriage and motherhood. The sacred canopy (Berger, 1967), which provides the theoretical context for this study, asserts that those who practice religion seek to act according to a religious worldview. This study examines the roles of personal faith, Church teachings, peer culture, and family upbringing in these women’s lives to determine how the sacred canopy is maintained. The analysis reveals how religious perspective has a slightly different role in the women’s lives than family upbringing, yet both work together to maintain the sacred canopy. This research is important for better understanding a demographic of a growing religious subpopulation and contextualizing their experiences. / Thesis (BA) — Boston College, 2014. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Sociology Honors Program. / Discipline: College Honors Program. / Discipline: Sociology.
52

Análise microclimática dos manguezais da Barra do Ribeira-Iguape/SP / Analysis microclimatic of mangroves in Barra of river Ribeira-Iguape / SP

Lima, Nádia Gilma Beserra de 30 July 2009 (has links)
O manguezal, definido como um ecossistema costeiro de transição entre os ambientes terrestres e marinhos caracteriza-se por ambiente salinizado e pela constante inundação causada por marés. Com destaque na área do Sistema Costeiro Cananéia Iguape, sua importância está relacionada à produção de biomassa, inserida no sistema bioenergético natural, aumentando a produtividade da zona costeira com a introdução de particulados orgânicos. Representam comunidades vegetais adaptadas a várias condicionantes físicas atuantes nas zonas costeiras, entre elas, as climáticas. Essa pesquisa objetivou analisar as variações dos atributos climáticos (temperatura do ar, umidade relativa do ar, radiação solar global, vento e pluviosidade) no manguezal, localizado na Barra do Ribeira- Iguape/SP, verificando se a variação existente está relacionada com as principais características da vegetação, mais especificamente pela presença de dossel no ambiente. Instalou-se uma torre microclimática contendo duas estações meteorológicas de forma a obter uma análise da variação dos atributos climáticos acima e abaixo do dossel de manguezal. Analisaram-se ainda as características estruturais do manguezal, visando comparar com os atributos climáticos. A presente pesquisa contribuiu para entender a variação dos atributos climáticos e sua influência na vegetação do manguezal. Verificou-se que, na escala de trabalho microclimática, os atributos do clima apresentam influência direta na distribuição espacial dessa vegetação. Além disso, as características do dossel é o principal controle para essa variação, principalmente na distribuição pluviométrica abaixo desse dossel, bem como na quantidade de radiação solar, que, consequentemente, influencia na distribuição das espécies vegetais do ambiente. / The mangrove is defined as a coastal ecosystem of transition between terrestrial and marine environments and is characterized by salinized environment and the constant flooding caused by tides. With emphasis in the area of coastal systems Cananéia - Iguape, its importance is more related to the production of biomass, inserted in the natural bioenergy system, that increases the productivity of the coastal zone with the introduction of organic particles. Represent plant communities adapted to different physical conditions in coastal areas, including the weather. This study aimed to analyze the changes of the attributes climate (air temperature, relative humidity, solar radiation, wind and rainfall) in the mangrove at the barra of Ribeira-Iguape/SP, checking if the variation is related to the main characteristics of vegetation, more specifically with the presence of the canopy at the environment. Was installed a tower containing two microclimatic weather stations to obtain an analysis of changes in climatic attributes above and below the canopy of mangrove. It was also analyzed the structural characteristics of mangrove, aiming to compare with the attributes climate. This research contributed to understanding the variation on the attributes of climate and its influence in the mangrove vegetation. It was found that, on the scale of work microclimatic, the attributes of climate have a direct influence on the spatial distribution of vegetation. Furthermore, the characteristics of the canopy are the main control for this variation, mainly in distribution of rainfall below the canopy and the amount of solar radiation, which consequently influences the distribution of plant species of the environment.
53

Determining Genetic Overlap between Staygreen, Leaf Wax and Canopy Temperature Depression in Sorghum RILs

Awika, Henry 2012 May 1900 (has links)
Crops adapted to dry conditions are essential to meet future food, feed and energy needs. Knowledge of interaction between drought tolerance traits and their response to varying water supply conditions would improve selection for yield stability traits. This study focused on determining the association between the QTL regulating the staygreen trait in sorghum with improved canopy temperature depression (CTD) as regulated by total and compositional epicuticular wax content in a recombinant inbred line population derived from BTx642 and RTx7000. Phenotypic data were collected in 3 replicated field trials and 1 greenhouse trial. Plants with higher leaf EWL had cooler canopies. Our results also confirmed that staygreen genotypes are able to maintain cooler canopy than the non-stay-green genotypes under drought and hot conditions. We have suggested that wax might offer a more stable indicator for selection of drought tolerance under a variety of weather conditions. Composite interval mapping identified a total of 28 QTL, fifteen of which had significant overlaps. The overlap between QTL for cuticular leaf wax and QTL for staygreen exhibits a departure from the QTL overlaps for other traits with that of cuticular leaf wax. We have also suggested that under drought stress, the QTL for staygreen may be expressed earlier in time (at anthesis) than had been previously believed.
54

Canopy Demographics at the Firestone Reserve, Costa Rica

Pera, Gizelle M 01 January 2010 (has links)
Though Costa Rica has suffered numerous bouts of deforestation to its valuable tropical rainforest area, especially in the 1970s, it has become a leader in its efforts to regenerate and restore its rainforest. However, studies and protocols for the assessment of forest regeneration are urgently required. Research has shown that the percentage of light penetrating the canopy floor, or light fraction, is a good indicator of rainforest maturity. In this study, digital rectilinear photography and a global positioning system receiver were used to survey the Firestone Reserve inCosta Rica in order to measure the light fraction differences between primary/riparian forest, bamboo plantation, secondary hardwood plantation, and natural secondary regrowth. The images were used to calculate light fractions with the software program ImageJ. Using ArcGIS, a kernel density plot was created, along with a map organizing the light fractions in the vegetation types. Significant differences in light fraction were found between bamboo and all other vegetation types, between secondary natural regrowth and secondary hardwood plantation, and between secondary natural regrowth and primary/riparian forest. No significance was noted between primary/riparian and secondary hardwood plantation, or between primary/riparian and secondary forest. Inaccuracies of the study could be due to the high amount of variance, low sample size, or high levels of sunlight that distort the photographs. Nevertheless, the study provided useful information concerning the differences between vegetation types and has implications towards regrowth and recovery of the rainforest.
55

Characterizing the Flax Core Collection for Earliness and Canopy Traits

2013 April 1900 (has links)
Early maturity is an important objective for breeding flax adapted to the Western Canada. Crop canopy traits influence seed yield; however, studying its effects is challenging due to the complexity and limited knowledge of the genetics of this trait. The objectives of this research are : i) to characterize flax accessions from the Canadian gene bank collection for early flowering, maturity and canopy traits; ii) to identify SSR markers associated with plant branching and leaf area index (LAI); iii) to use Structural Equation Modeling (SEM) to identify canopy variables with significant effects on yield. The flax core collection, consisting of approximately 381 accessions, was grown at the Kernen Crop Research Farm in 2010 and 2011. Additionally, 17 early and 17 late flowering accessions from the flax core collection were screened and their phenotypic responses in both growth chamber and field environments were measured. A large amount of phenotypic diversity was observed in long day and short day environments in these experiments. Some accessions appeared to be more photosensitive, while others were photoperiod insensitive. The genetic control of canopy traits such as LAI and plant branching were studied using association mapping. Genotyping of the core collection was conducted using 375 SSR markers. Population structure analysis assigned the 381 flax accessions in the core collection into four distinct groups. Model comparison revealed that the mixed linear model reduced spurious marker trait associations. A total of 26 markers were identified to be significantly associated with plant branching and LAI. The simultaneous examination of crop phenology and canopy traits to seed yield was performed using SEM analysis. The results indicated greater plant stand resulted in higher irradiance absorption and which resulted in greater seed yield. Days to flowering had a significant negative effect on seed yield and growing degree days to maturity had a significant effect on seed yield. Plant branching and plant height had a positive non-linear effect on seed yield. This study has provided several insights into molecular approaches and statistical methods to improve flax breeding.
56

none

wu, Ching-wen 22 July 2010 (has links)
none
57

Effect of Rate and Season of Application of Aminocyclopyrachlor on the Control of Acacia Farnesiana (L.) Willd. in South Texas

McGinty, Joshua 2012 May 1900 (has links)
This study was conducted on two rangeland sites in south Texas with large populations of huisache (Acacia farnesiana (L.) Willd.); the Bush Ranch in Goliad County, and the Hitchcock Ranch in Bee County. The purpose of the study was to evaluate the effect of three herbicide treatments and three seasons of application on 1) apparent mortality of huisache, 2) huisache canopy cover, 3) huisache stem density, and 4) herbaceous ground cover. Herbicide treatments included aminocyclopyrachlor alone at a rate of 0.315 kg a.i. ha-1, aminocyclopyrachlor + triclopyr at a rate of 0.210 kg a.i. ha-1 + 0.420 kg a.e. ha-1, and triclopyr + picloram at a rate of 0.560 kg a.e. ha-1 + 0.560 kg a.e. ha-1. Herbicide treatments were applied over 3 x 30 m plots containing previously mowed huisache in May, July, and October of 2010 with ground-broadcast equipment at a rate of 140 L ha-1. Randomly selected huisache individuals and herbaceous ground cover at randomly selected points were monitored for the duration of the study. Statistical analyses of huisache mortality, canopy area, and stem densities revealed that at both sites one year after treatment, huisache mortality across the three seasons of application was consistently higher in plots treated with aminocyclopyrachlor + triclopyr (50 to 99%) versus those treated with aminocyclopyrachlor alone (16 to 78%) or triclopyr + picloram (4 to 70%). This mixture also provided the greatest reductions in huisache canopy area (60 to 99% reduction) and stem density (61 to 99% reduction). Also at both sites, spring applications consistently provided the greatest huisache control and canopy and stem reductions. Herbicide treatment and season of application had little effect on post-treatment herbaceous ground cover, likely due to extreme drought conditions in 2011. Of the possible combinations of seasons of application and herbicide treatments, the application in the spring of aminocyclopyrachlor plus triclopyr provided the most desirable results in terms of huisache mortality, canopy reduction, and stem density reduction. However, for sites invaded by huisache that are located near to potentially susceptible crops, the application of aminocyclopyrachlor plus triclopyr or aminocyclopyrachlor alone in the fall after the harvest of those crops may be more appropriate in order to avoid non-target injury while still providing acceptable huisache control.
58

Exploring the relationships between vegetation measurements and temperature in residential areas by integrating LIDAR and remotely sensed imagery

Clemonds, Matthew A 30 October 2006 (has links)
Population growth and urban sprawl have contributed to the formation of significant urban heat island phenomena in Houston, Texas, the fourth largest city in the United States. The population growth in Houston was 25.8% between 1990 and 2000 nearly double the national average. The demand for information concerning the effects of urban and suburban development is growing. Houston is currently the only major US city lacking any kind of comprehensive city zoning ordinances. The Normalized Difference Vegetation Index (NDVI) has been used as a surrogate variable to estimate land surface temperatures at higher spatial resolutions, given the fact that a high-resolution remotely sensed NDVI can be created almost effortlessly and remotely sensed thermal data at higher resolutions is much more difficult to obtain. This has allowed researchers to study urban heat island dynamics at a micro-scale. However, this study suggests that a vegetation index alone might not be the best surrogate variable for providing information regarding the independent effects and level of contribution that tree canopy, grass, and low-lying plants have on surface temperatures in residential neighborhoods. This research combines LIDAR (Light Detection and Ranging) feature height data and high-resolution infrared aerial photos to measure the characteristics of the micro-structure of residential areas (residentialstructure), derives various descriptive vegetation measurement statistics, and correlates the spatial distribution of surface temperature to the type and amount of vegetation cover in residential areas. Regression analysis is used to quantify the independent influence that different residential-structures have on surface temperature. In regard to implementing changes at a neighborhood level, the descriptive statistics derived for residential-structure at a micro-scale may provide useful information to decision-makers and may reveal a guide for future developers concerned with mitigating the negative effects of urban heat island phenomena.
59

The relationship between canopy structure, light dynamics and deciduousness in a seasonal tropical forest in Panama : a multiple scale study using remote sensing and allometry /

Bohlman, Stephanie Ann. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 165-194).
60

Species diversity, regeneration and early growth of Sal forests in Nepal responses to inherent disturbance regimes /

Sapkota, Indra, January 2009 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2009. / Härtill 4 uppsatser.

Page generated in 0.033 seconds