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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.
61

Relation of nutritional status, immunity, hemoglobinopathy and falciparum malaria infection

Nyakeriga, Alice January 2005 (has links)
The interaction between nutritional status and malaria disease is complex and often controversial. Nutritional deficiencies (macro- or micro-nutrient) are thought to lead to malnutrition with subsequent susceptibility to malaria infection. On the other hand severe malaria or repeated malaria infections lead to malnutrition. While the cause and effect are difficult to attribute, micronutrient deficiencies such as iron deficiency and malaria infection often co-exist and show complex interactions leading to mutually reinforced detrimental clinical effects. That iron deficiency has adverse effects on human health is widely recognized. Iron plays a crucial role in processes of growth and cell division and in the transport of oxygen throughout the body. It is also important for the proliferation of cells of the immune system as well as for microorganisms including the malaria parasite. Iron deficiency results in a decrease in hemoglobin concentrations and subsequent anemia. However, the etiology of anemia is multi-factorial and may be affected, in addition, by several factors including malaria and host factors, especially hemoglobinopathies such as alpha-thalassemia and sickle cell trait. These hemoglobinopathies are also common in malaria endemic areas. In this thesis, we have investigated the relationship between nutritional status, immunity, hemoglobinopathies and falciparum malaria in a cohort of children less than 8 years old living on the coast of Kenya. We have found that malaria was associated with malnutrition in an age-dependent fashion. Malaria was associated with subsequent underweight or stunting in children under the age of 2 years, but this effect was not there in older children. Also, we observed that iron deficiency was associated with protection of children against clinical malaria. Children who were iron deficient had a lower incidence of malaria episodes as compared to those who were iron replete. While studies on the effects of single micronutrient deficiencies on components of the immune system are difficult to design and interpret, there is ample evidence that micronutrient deficiencies, in general, affect all components of immunity. In line with this, we found that nutritional iron status was associated with certain malaria-specific immunoglobulins and interleukin-4 mRNA levels. Iron deficient children had lower levels of malaria-specific IgG2 and IgG4 but higher expression levels of IL-4 mRNA as compared to the iron replete children. Finally, we observed a tendency towards a higher prevalence of iron deficiency in children carrying either alpha-thalassemia or sickle cell trait.
62

Kayraktepe Dam And Hepp, Environmentally Acceptable Alternative Solution

Sever, Ozgur 01 December 2010 (has links) (PDF)
In this study, alternative solution of Kayraktepe Dam is investigated. Kayraktepe Dam was planned more than 30 years ago, but due to various reasons the construction could not be realized. In this study, an alternative feasible formulation was developed. Former Kayraktepe Dam was planned for multiple objectives: flood control, energy generation and water supply for irrigation. The newly developed formulation was designed to meet these objects as well.
63

Sol-gel Processing Of Organically Modified Ito Thin Films And Characterization Of Their Optoelectronic And Microstructural Properties

Kesim, Mehmet Tumerkan 01 August 2012 (has links) (PDF)
Indium tin oxide (ITO) thin films were formed on glass substrates by sol-gel method. Coating sols were prepared using indium chloride tetrahydrate (InCl3&bull / 4H2O) and tin-chloride pentahydrate (SnCl4&bull / 5H2O) stabilized in organic solvents (acetylacetone and ethanol). First attempt was to synthesize ITO thin films using standard/unmodified coating sols. The effect of calcination treatment in air (300 &ndash / 600 &deg / C) and number of coating layer(s) (1, 4, 7 or 10) on optoelectronic properties (electrical conductivity and optical transparency), crystal structure and microstructure of ITO thin films were investigated. In addition, single-layer ITO thin films with optoelectronic properties comparable to multi-layered films were prepared by employing organically modified coating sols. Oxalic acid dihydrate (OAD) &ndash / a drying/microstructure control agent&ndash / addition to standard sol formulation was achieved. The rationale was to improve the optoelectronic properties of ITO films through enhancement in microstructure and chemical characteristics upon OAD addition. The effects of OAD content in the sol formulation and post-coating calcination treatment on electrical/optical properties of ITO films have been reported. Finally, the effects of post coating drying temperature (100 &ndash / 200 &deg / C) and time (10 &ndash / 60 min) on optoelectronic and microstructural properties of OAD-modified ITO thin films were discussed. Thin films have been characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD),x-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis) spectroscopy, fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM) and four-point probe measurement techniques. It was shown that film formation efficiency, surface coverage and homogeneity were all enhanced with OAD addition. OAD modification also leads to a significant improvement in electrical conductivity without affecting the film thickness (45&plusmn / 3 nm). Highly transparent (98 % transmittance in visible region) ITO thin films with a sheet resistance as low as 3.8&plusmn / 0.4 k&Omega / /sqr have been obtained by employing coating sols with optimized OAD amount (0.75 M). The optimum post-coating drying temperature (100 &deg / C) and drying time (10 min) was also determined for 0.75 M OAD-modified ITO thin films.
64

A critical review of Hong Kong air quality data /

Ip, To-yan, Francis. January 2001 (has links)
Thesis (M. Sc.)--University of Hong Kong, 2001. / Includes bibliographical references (p. [84-85]).
65

Lietuvos pensijų fondų pelningumo irn investicinės grąžos įvertinimas / The profitability and return on investment evaluation of Lithuanian pension funds

Rutalytė, Giedrė, Jonikaitė, Aiveta 02 September 2010 (has links)
Bakalauro baigiamajame darbe nagrinėjamas Lietuvos pensijų fondų pelningumas ir investicinė grąža. Teorinėje dalyje atskleistos pensijų fondų atsiradimo prielaidos, išanalizuota pensijų fondų samprata ir klasifikavimas, pensijų fondams taikomi mokesčiai, apibūdinami pensijų fondų privalumai ir trūkumai bei investavimo strategijos, aptariamas teisinis reglamentavimas, aprašomas pensijų fondų pelningumo, rizikos ir investicinės grąžos skaičiavimas. Tiriamojoje baigiamojo darbo dalyje pateikiama Lietuvoje veikiančių II ir III pakopos pensijų fondų apžvalga; atlikta pensijų fondų mokesčių analizė pagal investavimo kryptis, išanalizuoti pensijų fondų grynųjų aktyvų verčių pokyčiai, apskaičiuoti ir išanalizuoti pensijų fondų pelningumo, grynosios grąžos ir rizikos rodikliai, įvertinta, kiek dalyviai galėjo sukaupti, dalyvaudami pensijų kaupime, nuo pensijų fondų veiklos pradžios iki 2009 m. pirmo pusmečio. / The profitability and return on investment of Lithuanian pension funds are analyzed in the final work of bachelor. The assumptions of pension funds are disclosed in the theoretical part. Also, theoretical part analyzes the concept and classification of pension funds, taxes which are applicabled for pension funds, the advantages and disadvantages of pension funds. Moreover, the investment strategies, legal regulations, the calculation of pension funds profitability, risk and return of pension funds are analyzed in theoretical part. The overview of second and third levels Lithuanian’s pension funds are accomplished in the empirical part. Moreover, empirical part presents the taxation analysis of pension funds according to investment directions, presents values changes of the pension funds net assets. We have calculated and analyzed profitability, net return and risk indexes of pension funds. Also, we assessed how much participants could accumulate by participating in the pension accumulation from the beginning of pension funds till second half of 2009 year.
66

Bounds on distance-based topological indices in graphs.

Morgan, Megan Jane. January 2012 (has links)
This thesis details the results of investigations into bounds on some distance-based topological indices. The thesis consists of six chapters. In the first chapter we define the standard graph theory concepts, and introduce the distance-based graph invariants called topological indices. We give some background to these mathematical models, and show their applications, which are largely in chemistry and pharmacology. To complete the chapter we present some known results which will be relevant to the work. Chapter 2 focuses on the topological index called the eccentric connectivity index. We obtain an exact lower bound on this index, in terms of order, and show that this bound is sharp. An asymptotically sharp upper bound is also derived. In addition, for trees of given order, when the diameter is also prescribed, tight upper and lower bounds are provided. Our investigation into the eccentric connectivity index continues in Chapter 3. We generalize a result on trees from the previous chapter, proving that the known tight lower bound on the index for a tree in terms of order and diameter, is also valid for a graph of given order and diameter. In Chapter 4, we turn to bounds on the eccentric connectivity index in terms of order and minimum degree. We first consider graphs with constant degree (regular graphs). Došlić, Saheli & Vukičević, and Ilić posed the problem of determining extremal graphs with respect to our index, for regular (and more specifically, cubic) graphs. In addressing this open problem, we find upper and lower bounds for the index. We also provide an extremal graph for the upper bound. Thereafter, the chapter continues with a consideration of minimum degree. For given order and minimum degree, an asymptotically sharp upper bound on the index is derived. In Chapter 5, we turn our focus to the well-studied Wiener index. For trees of given order, we determine a sharp upper bound on this index, in terms of the eccentric connectivity index. With the use of spanning trees, this bound is then generalized to graphs. Yet another distance-based topological index, the degree distance, is considered in Chapter 6. We find an asymptotically sharp upper bound on this index, for a graph of given order. This proof definitively settles a conjecture posed by Tomescu in 1999. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2012.
67

An examination of indexes for determining the number of clusters in binary data sets

Weingessel, Andreas, Dimitriadou, Evgenia, Dolnicar, Sara January 1999 (has links) (PDF)
An examination of 14 indexes for determining the number of clusters is conducted on artificial binary data sets being generated according to various design factors. To provide a variety of clustering solutions the data sets are analyzed by different non hierarchical clustering methods. The purpose of the paper is to present the performance and the ability of an index to detect the proper number of clusters in a binary data set under various conditions and different difficulty levels. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"
68

Economic values and responses to selection using selection indices in swine

Holzbauer, Regina. January 1998 (has links)
The objective of this study was to derive new selection indices for swine production in Quebec. First economic values were derived as change in profit per market pig for a one unit change in a trait while all other traits remain unchanged. Production figures and prices used were taken from Quebec figures. Comparing with the currently used economic values, the responses showed the same range for the sire line with a higher emphasis on age to 100 kg for the new values. The same trait, response in age to 100 kg was much smaller in the maternal line for the newly derived economic values but showed higher responses for backfat and litter size. Lean yield was found to have higher responses if used directly as a selection criterion for carcass composition instead of backfat. Feed intake was found to have unfavourable responses in the maternal line but did not change the responses for the paternal line. Including farrowing interval in the maternal line resulted in favourable responses for lean yield and litter size. Regulating the backfat level using a restricted index in the dam line had no effect on the other traits in the index.
69

A System Approach To Occupational Health And Safety Management

Gozuyilmaz, Cem 01 December 2003 (has links) (PDF)
In this thesis, methods used at present in occupational health and safety management are analyzed and a model safety management system is developed. History, development and recent occupational safety regulations in the United States of America and European Union are introduced to give a sight on this subject in developed countries. The suggested model is evaluated with work accident data taken from a company and hazard and risk analysis methods are used to investigate these accidents. Preventive measures to eliminate and reduce the consequences of these accidents are recommended. Finally a model safety management system which can be used in all types of industry is developed.
70

Scanner data and the construction of price indices.

Ivancic, Lorraine, Economics, Australian School of Business, UNSW January 2007 (has links)
This thesis explores whether scanner data can be used to inform Consumer Price Index (CPI) construction, with particular reference to the issues of substitution bias and choice of aggregation dimensions. The potential costs and benefits of using scanner data are reviewed. Existing estimates of substitution bias are found to show considerable variation. An Australian scanner data set is used to estimate substitution bias for six different aggregation methods and for fixed base and superlative indexes. Direct and chained indexes are also calculated. Estimates of substitution bias are found to be highly sensitive to both the method of aggregation used and whether direct or chained indexes were used. The ILO (2004) recommends the use of dissimilarity indexes to determine the issue of when to chain. This thesis provides the first empirical study of dissimilarity indexes in this context. The results indicate that dissimilarity indexes may not be sufficient to resolve the issue. A Constant Elasticity of Substitution (CES) index provides an approximate estimate of substitution-bias-free price change, without the need for current period expenditure weights. However, an elasticity parameter is needed. Two methods, referred to as the algebraic and econometric methods, were used to estimate the elasticity parameter. The econometric approach involved the estimation of a system of equations proposed by Diewert (2002a). This system has not been estimated previously. The results show a relatively high level of substitution at the elementary aggregate level, which supports the use a Jevons index, rather than Carli or Dutot indexes, at this level. Elasticity parameter estimates were found to vary considerably across time, and statistical testing showed that elasticity parameter estimates were significantly different across estimation methods. Aggregation is an extremely important issue in the compilation of the CPI. However, little information exists about 'appropriate' aggregation methods. Aggregation is typically recommended over 'homogenous' units. An hedonic framework is used to test for item homogeneity across four supermarket chains and across all stores within each chain. This is a novel approach. The results show that treating the same good as homogenous across stores which belong to the same chain may be recommended.

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