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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.
1

IMPACT OF SEASON AND HEAT STRESS ON SOMATIC CELL COUNTS

Broaddus, Brent A. 01 January 2001 (has links)
Infection data were obtained monthly from June, 1999 to September, 2000 at the University ofKentucky dairy. Quarter foremilk samples were collected for bacteriological determination andsomatic cell counts (SCC). The Livestock Stress Index (LSI) estimated heat stress and is calculatedby combination of temperature and humidity. For uninfected quarters the geometric mean SCC was29,000 cells/ml. For infected quarters the geometric mean SCC was 213,000 cells/ml. Coagulasenegativestaphylococci (CNS) infections comprised 61 percent of the total infected quarters with ageometric mean SCC of 155,000 cells/ml. Staphylococcus aureus infected quarters had a geometricmean SCC of 680,000 cells/ml. There were no significant correlations between log SCC and LSIwhen looking at the total sample period. However, evaluating October, 1999 through September,2000, significant correlations were found for LSI and log SCC of uninfected quarters (P andlt; 0.05) and`infected quarters (P andlt; 0.0001). All correlation coefficients were less than 0.12. The results suggest nomarked changes in SCC were observed in uninfected quarters during hot summer weather. Hotsummer weather may have a minor impact on SCC in infected quarters, but the effect is variable.Thus, infection status of the mammary gland, not heat stress, is the major factor determining SCC.
2

An Investigation of the Parenting Stress Index in the Context of Generalizability Theory

Sharpnack, Jim D. 01 May 1997 (has links)
This present study examined the application of generalizability theory (GT) to the Parenting Stress Index (PSI) long and short forms for families having children with disabilities. The purpose of the study was to evaluate the dependability of parenting stress data scores gathered from families having children with disabilities. The data for the present study came from an extant data set collected by the Early Intervention Research Institute (EIRI; Contract #800-85-0173) at Utah State University. The EIRI studies represented attempts to assess the benefits and cost of conducting early intervention programs. The EIRI data were recoded at the item level for the Psychometrics Project, which established norms, reliability, and validity information on self-report, family-functioning measures gathered from families having children with disabilities. The GT study results suggested that the items facet made a large contribution, indicating that there may not be any established trends in item responses. An explanation for the items facet indicates that the PSI forms provide an accurate measure of overall parental stress. According to the times facet results, the effects of time are minimal except the increase between occasion one to occasion two. Classical reliability theory (CRT) and GT analyses provide contradictory results, probably due to GT's multiple error source analyses compared to CRT's examination of a single error source in one analysis. GT study analyses indicate that the highest g and phi coefficients are produced with the highest number of administrations and items. However, administering the highest number of administrations and items would be impractical within any setting. The original number of items from the Parent Domain, Child Domain, and short PSI total score should be administered twice to increase the dependability of scores and still fall within practical limitations. A researcher and/or practitioner may want information to decide what form, long or short, to choose. If the PSI is to be used as a quick screening tool or as one test in a complete assessment, the short form may be of more use. If the PSI is to be used as a primary source of information about parent and child interactive systems, the long PSI version would be recommended.
3

Spatial Precipitation Variability, Snowfall, and Historical Bison Occurrence in the Northwest United States

Williams, Heather Anna 08 August 2005 (has links)
Throughout the Holocene, bison have always been more abundant east of the Rocky Mountains with considerably fewer bison found west of the Rocky Mountains. It is likely that drought frequency and snowfall characteristics have influenced the pattern of historical bison occurrence across the northwest United States. Using monthly average snow and precipitation data from the past several decades, average April snow water equivalent (SWE) and summertime drought frequency were analyzed at sites across the northwest United States. A climatic stress index (CSI) was developed by combining average SWE and drought frequency for sites, as these are the climate factors that will most likely affect bison success. The results of the CSI revealed that locations west of the Rockies experience heavier snowfall and a greater frequency of droughts, thus presenting a “double whammy” of climate conditions that bison would have to endure. The locations of highest combined snow and drought frequencies coincide with locations of low bison occurrence.
4

Effect of gender & lifestyle on Cardio Stress Index & Heart Rate Variability

Nortje, Evangeline January 2014 (has links)
The importance of physical exercise tends to be neglected in today’s modern lifestyle. This increased passive way of life conveys a notable increase in the prevalence of lifestyle disorders such as hypertension and vascular pathology which lead to cardiovascular strain. Taking this into account, the aim of this investigation was to explore the empirical association between the heart health status of an active and sedentary South African lifestyle, thus intending to provide insight into impact of the significant changes that are associated with the modernised society. With the aforementioned objective in mind, four separate studies were completed: Study 1 sought to investigate the cardiovascular status of 162 undergraduate university students in order to determine whether, despite their youth, students remained at risk of cardiovascular complications. Astonishingly, results indicate that a number of students between the ages of 18 and 25 in a university setting present with preeminent cardiovascular risk. This data highlights some serious concerns regarding the cardiovascular health among the youth. In sequel to study 1, study 2 permitted the comparison of a sedentary and active South African population, however some discrepancies originated due to the notable age difference between the groups. Nevertheless, results gained from this crosssectional comparison between the populations indicate significantly higher cardiac risk amongst the sedentary population. Study 3 was conducted on 202 infantry service recruits between the ages of 18 and 24 years. A pre- post intervention study design was incorporated in pursuit of determining the influence of an intense training programme on cardiovascular variables of a population over a 20 week time-frame. Results yielded from this study indicate a significant decrease in overall cardiovascular risk, as tested over three intervals (week 1, week 12, and week 20) during the 20 week training period. Study 4 was designed as a longitudinal study with self-controls for within group comparisons, as well as a comparative study between the two contrasting populations. Thus, affording the opportunity to determine the impact of physical activity on cardiovascular risk by comparing two divergent South African lifestyles over a 20-week time frame. The 202 infantry service recruits of study 3 served as the intervention group, while the control group comprised of 126 sedentary university students. Findings from this study conveyed strong association between the active population and decreased cardio-stress index and related heart health measurements in comparison to results of the sedentary population. This research validates the positive correlation between a physically active lifestyle and improved heart health, thereby implying reduced cardiovascular risk. In the combat against cardiovascular disease it is clear that focus should be shifted from pharmacological treatment to behavioural prevention. As a principle component of this preventative approach it is vital that individuals are equipped with screening technology that enables early detection and monitoring of probable cardiovascular complications. Several novel ideas were introduced in this research, including the endorsement of the cardio-stress index method as an efficient non-invasive technique to directly observe cardiovascular stress. / Dissertation (MSc)--University of Pretoria, 2014. / lk2014 / Physiology / MSc / Unrestricted
5

Modelování indexu finančního stresu v České republice pomocí vektorové autoregrese / Modelling of Financial Stress Index in the Czech Republic using Vector Autoregression Analysis

Malega, Ján January 2015 (has links)
This study constructs a financial stress index with a specific focus on the case of the Czech Republic. The advantage of the index is primarily its ability to measure the current level of stress in the financial system incorporating information from various sectors of the economy and expressing it in a single-value statistic. Our index successfully recorded and evaluated critical periods of elevated financial stress especially during the recent financial crisis. Furthermore, we examine a systematic interaction between financial stress and the macroeconomics using vector autoregression analysis along with method of impulse responses. Based on our results we observe a significant and positive response of unemployment due to the shock in financial stress. Conversely, a negative effect was examined on inflation and interest rates. JEL Classification G17, G32 Keywords financial stress index, vector autoregression, impulse responses
6

Financial Stress Transmission from Developed to Emerging Countries

Gavrilenco, Nicolae January 2013 (has links)
Charles University in Prague Faculty of Social Sciences Institute of Economic Studies MASTER THESIS Financial Stress Transmission from Developed to Emerging Countries Author: Bc. Nicolae Gavrilenco Supervisor: doc. Roman Horvàth, Ph.D. Academic Year: 2012/2013 Abstract In this research we have analyzed the financial system as it is today, describing the implications financial innovation had and the impact of the recent financial crisis. We tried to understand the nature of the financial stress and its measures. In the context of world financial integration it was also necessary to have a review upon the financial stress transmission channels from developed to emerging countries, determining the linkages and their measures. We employed a structural VAR model to determine whether there is empirical proof of financial Stress transmission from developed to emerging countries and see if financial integration represents the decisive factor in financial stress transmission. Our results suggest that there is a significant impact of financial stress in developed countries on the output of emerging ones. However we can observe an increasing influence of country-specific factors in explaining the variation in the rest of the variable of our model. The results also indicate the level of international financial...
7

The development, validation and implementation of a drought stress index for the evaluation of the drought tolerance potential of South African sugarcane

Sewpersad, Chandani 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In the rainfed areas of the South African sugar industry the unpredictability of rainfall is of major concern for producers. Currently, research into the drought tolerance of South African sugarcane varieties is very limited. Knowledge of varietal drought tolerance potential would allow for more informed decision making when it comes to planting a crop that stays in the ground for between five and fifteen years. The aim of this study was to ascertain the drought tolerance potential of commercial sugarcane varieties using historical field trial data by employing statistical modelling. The first step was to establish a reliable methodology of quantifying the level of drought stress, defined through a drought stress index (DSI), employing the sugarcane growth modelling software Canesim. The second step was to use the selected DSI to evaluate and rate the drought tolerance potential of commercial varieties. Of the six DSI’s calculated, the index comprising a ratio of Canesim simulated rainfed yield (representative of a water stressed environment) to Canesim simulated irrigated yield (representative of a water unstressed environment) was the best at quantifyingthe level of trial drought stress. Using three varieties with previously identified drought potential, two intermediate susceptible (IS) and one intermediate (I) variety, this was the only DSI that was able to quantify all the differences between the varieties. Using the selected DSI, two different methodologies were used to evaluate varietal drought tolerance potential: General linear regression and Residual maximum likelihood meta-analysis. The regression method proved to be a better method of varietal rating when using historical field data. The two rainfed regions, coastal and midlands were analyzed separately due to the difference in climatic conditions. Using the regression analysis, with N12 as the observed intermediate reference variety, coastal varieties were rated as being susceptible (N16, N19, N39 and NCO376) or intermediate (N27, N29, N33, N36, N41, N45, N47). Rating of the midlands varieties, with both statistical methods, were unsuccessful. / AFRIKAANSE OPSOMMING: Binne die droëland produksiegebied van die Suid-Afrikaanse suikerindustrie is die wisselvalligheid van reënval ʼn groot bron van kommer vir produsente. Navorsingsresultate aangaande die droogtetoleransie van Suid-Afrikaanse suikerrietvariëteite is baie beperk. Aangesien suikerriet aanplantings vir vyf tot vyftien jaar in produksie mag bly, is kennis aangaande droogtetoleransie noodsaaklik vir ingeligte besluite rondom variëteit keuse. Die doel van hierdie studie was om die droogtetoleransie van kommersiële variëteite met behulp van historiese veldproef resultate en statistiese modellering te bepaal. Die eerste stap was die ontwikkeling van betroubare metodiek wat die graad van droogtestremming kwantifiseer deur middel van droogtestremmingsindekse (DSI’s) wat met die suikerriet produksiemodel, Canesim, bereken is. Die tweede stap was om die DSI’s te gebruik om geselekteerde kommersiële variëteite vir droogtetoleransie te evalueer en volgens toleransie te rangskik. Van die ses DSI’s wat geëvalueer is, was die indeks wat die verhouding tussen Canesim gesimuleerde droëland opbrengs (verteenwoordigend van ʼn omgewing met droogte) en Canesim gesimuleerde besproeide opbrengs (verteenwoordigend van ʼn omgewing sonder droogte) omskryf het, die mees effektiefste om die graad van droogtestremming te kwantifiseer. Hierdie DSI was vervolgens die enigste wat verskille in droogtetoleransie tussen drie variëteite van bekende droogte toleransie kon kwantifiseer. Deur gebruik van hierdie DSI is twee verskillende metodes aangewend om die droogtetoleransie van variëteite te evalueer naamlik: Algemene Lineêre Regressie en Residuele Maksimum Aanneemlikheid. Die regressiemetode was die mees effektiefste om variëteite volgens droogtetoleransie, op grond van historiese veldproef resultate, te rangskik. Die twee droëland produksiegebiede, naamlik die kusstrook en Natalse Middellande is afsonderlik geanaliseer as gevolg van klimaatsverskille. Met behulp van die regressiemetode is die kus-variëteite as droogtesensitief of -intermediêr geklassifiseer, met N27, N29, N33, N36, N41, N45 en N47 as droogte-intermediêr en N16, N19, N39 en NCO376 as droogtesensitief. Soortgelyke klassifisering van die variëteite wat in die Natalse Middellande verbou word was nie met enige van die statistiese metodes suksesvol gewees nie.
8

The Relationship Between Stress Levels and Job Satisfaction among Community College Faculty in East Tennessee.

McCracken, Carolyn G. 01 December 2001 (has links)
Data pertaining to stress and job satisfaction of faculty at five Tennessee Board of Regents community colleges in east Tennessee were collected and analyzed in this study. Questionnaires were distributed to all full-time faculty at the colleges, with 51.3% returned. Questionnaires consisted of a socio-demographic survey, the Faculty Stress Index (FSI) to measure stress levels, and the Job Descriptive Index (JDI) to measure job satisfaction. Of those responding, 92.4% were white, 76.5% were married, 61.2% were female, 58.9% were tenured, and 81.3% were 40 or older, with 52.2% over 50. Only 1.9% were 30 or younger, but 51.1% had been in their current positions for six years or less. A total of 72.4% were assistant (22.9%) or associate (49.5%) professors, with 19.2% ranking as instructors and 8.4% as professors. Previous factor analysis of FSI items determined the dimensions Reward/Recognition, Time Constraints, Departmental Influence, and Student Interaction. In this study, faculty FSI scores implied low stress levels in Reward/Recognition and Departmental Influence, with moderate levels in Time Constraints and Student Interaction. Those in position for less than three years, non-whites, and non-tenured faculty reported significantly less stress in Student Interaction. Tenured faculty and associate professors were significantly more pressured by Time Constraints than non-tenured or other-ranked faculty. The JDI consisted of six sub-scales: Work on Job, Pay, Opportunities for Promotion, Supervision, People on Job, and Job in General. Respondents indicated high satisfaction in Work, Supervision, People, and Job in General but showed dissatisfaction with Pay. Negative feelings were measured in Opportunities for Promotion, with significantly less satisfaction for older, more experienced, tenured faculty, and associate professors. Non-tenured faculty members were significantly more satisfied in Work and Supervision than were tenured respondents. Correlation analysis showed significant inverse relationships among all FSI dimensions and JDI sub-scales. In hierarchical multiple regression analyses, FSI dimensions were significant predictors of satisfaction in all JDI sub-scales, whereas the socio-demographic variables were significant predictors only for Opportunities for Promotion. Recommended were longitudinal studies of stress and satisfaction among specific groups and/or colleges. Encouraged were stress management programs and improved systems of reward and recognition for faculty.
9

Využití makroobezřetnostní politiky a indikátorů rizika pro regulaci finančních trhů / Using of Macroprudential Policy and Risk Indicarors for Financial Markets Regulation

Šimáček, Milan January 2012 (has links)
This dissertation provides a complex study of systemic financial risk and its quantification. In the first part, the paper summarizes the main assumptions and tools of macroprudential policy, which became an important regulatory policy after the financial crisis of 2007-2009. The main parts of the paper deal with the construction of indicators of financial systemic risk and stress, where the paper distinguishes the quantitative expression of the contemporaneous financial stress from the continually developing systemic risk. The paper analyzes several methods of financial stress index construction, whose main task is to identify the contemporaneous rate of risk in different sectors of financial system using market prices of assets. The outcome of the paper is the identification and historical description of periods of heightened financial stress and the recognition of a regional character of the periods of stress. Apart from the index of the contemporaneous stress of financial system, the paper brings a systemic risk indicator, which captures the development of systemic risk in time, and which is a suitable leading indicator for the identification of periods of financial stress. The systemic risk indicator has identified, with a lead of two to three years, the increasing risk of the banking sectors of the countries in the region before the onset of the financial crisis of 2007-2009. In the conclusion, the paper points out the suitability of both indicators for the calculation of the amount of countercyclical capital buffer used in the new Basel III measures.
10

Evaluation of sorghum genotypes for variation in canopy temperature and drought tolerance

Mutava, Raymond Ngao January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / P.V. Vara Prasad / Sorghum (Sorghum bicolor L. Moench) is the fifth most economically important cereal crop grown worldwide and adapted to a wide range of climatic conditions. Drought stress has been ranked as one of the most significant causes of crop yield loss with its effects on yield and yield components. Conservative water use by plants is one of the strategies that can be used as a drought coping mechanism. The slow wilting trait has been associated with conservative water use and has been found in some sorghum genotypes. The purpose of this study was to use canopy temperature to screen for drought tolerance in sorghum, evaluate water use efficiency for slow wilting sorghum genotypes and determine variability in root morphology and response to drought among sorghum genotypes. Canopy temperature studies were conducted under field conditions using infrared (IR) sensors while water use efficiency and root studies were conducted under greenhouse conditions. Our results showed a distinct separation in canopy temperature among genotypes under field conditions at 2:00 pm to 6:00 pm. Midday canopy temperature depression (CTD) was positively correlated to yield (R2 = 0.19) and harvest index (R2 = 0.11). CTD was also stable for all the genotypes during the period from 1:00 pm to 7:00 pm. There was a negative correlation between CTD and crop water stress index (CWSI) (R2 = 0.34) and a positive one between canopy temperature and CWSI (R2 = 0.50). Evaluation of genotypes for water use efficiency revealed significant variability among sorghum genotypes in the amount of water used (10.48 – 13.52 kg) and transpiration efficiency (TE) (2.64 – 7.11 g kg-1) among genotypes. Slow wilting genotypes were high in TE. Rooting depth increased for some genotypes under drought stress with genotype SC1124 recording the largest increase (180%). Total root length for some genotypes increased by 11 – 113% with genotypes SC224 and SC1019 recording the greatest increase. There was a positive correlation between water used and root length (R2 = 0.21). These results show that there is potential for selection of drought tolerance in sorghum and that genotypes with the slow wilting traits are efficient in water use.

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