Five long-run average cost curves were derived from questionnaire and interview data by connecting points corresponding to the per unit production costs and levels of beef output for four cattle ranch sizes (50, 150, 300, and 500 head of breeding cows). Analysis of the long-run average cost curves in combination with the 1968 weighted Utah beef price revealed that all four ranch sizes studied are capable of meeting cash costs. If the goal of the ranch operator is to meet both cash costs and depreciation, a cattle ranch supporting 105 breeding cows is the minimum size necessary. If provision is made to cover cash costs and depreciation in addition to receiving a fair return for operator and family labor, the ranch must support at least 360 breeding cows. None of the four ranch sizes studied were capable of meeting all production costs including five per cent interest on investment. The minimum ranch size necessary to cover all production costs including 1 . 4 per cent interest on investment is 500 head of breeding cows. Farmer questionnaires and the machine capacity technique provided data from which five long-run average cost curves were derived by connecting points representing average production costs and levels of wheat output for four sizes of wheat farms (500, 1000, 2000, and 3000 acres). The long-run average cost curves were analyzed in combination with the 1968 Utah wheat price. All four wheat farm sizes studied are capable of meeting cash costs. In order to cover both cash costs and depreciation a wheat farm of at least 940 acres is required. The minimum wheat farm size necessary to meet cash costs and depreciation as well as provide a fair return to operator and family labor is 2430 acres. None of the four sizes of wheat farms studied was large enough to cover all costs including interest on investment at five per cent. In order to cover all production costs including 0,64 per cent interest on investment a wheat farm of at least 3000 acres is required, Costs and returns to five management alternatives for marginal Utah cropland ( (1) wheat production by owner-operator, (2) leasing crop.. land to tenants for dryland wheat production, (3) leasing forage on an AUM basis, (4) leasing of forage on a livestock gain basis, and (5) stocker cattle production by the land owner) were compared in the shortrun, in the long-run assuming that all inputs were variable, and in the long-run assuming that land and operator and family labor were fixed, For the marginal cropland owner who also owns wheat production factors, wheat production on an owner-operator basis is the most favorable short-run alternative. Wheat production on a tenant basis is the only short-run alternative open to cropland owners who own neither wheat production factors nor the improvements necessary for grazing enterprises. Leasing forage on a livestock gain basis is the most favorable short-run alternative for cropland owners whose holdings are equipped with grazing improvements. For the long-run situation in which all inputs were considered variable, all five management alternatives yielded negative returns. Under such conditions a rational land owner would refuse to choose from among the five alternatives studied and would instead liquidate his land holdings. When operator and family labor and land were considered fixed, leasing cropland to tenants for dryland wheat production proved to be the most favorable long-run management alternative. Showing the second highest internal rate of return was leasing forage on a livestock gain basis followed ~ stocker cattle production by the land owner. Wheat production ~ the land owner and leasing forage on an AUM basis proved to be the least favorable long-run management alternatives on marginal cropland.

Magister Scientiae Dentium - MSc(Dent) / Background: A close marginal adaptation between the tooth and the bracket base is important since it provides the space for the adhesive. In order to withstand and resist the orthodontic forces exerted as well as everyday forces like mastication and oral hygiene practices, the adhesive material to the bracket must have sufficient sheer bond strength. This means that no deformations, cracks, or fractures should occur within the bracket material and adhesive (Keizer et al., 1976). Aim: The aim of this study was to determine the accuracy of the marginal adaptation of the bracket bases of seven different brands of orthodontic brackets to the tooth surface of a right upper first premolar (ie. Abzil, Forestadent, GAC, Gemini, IMD, Ormco and Victory LP). Method: This research was an in vitro, descriptive comparison study. Fifteen caries and crack free intact human first premolars were used. The teeth were obtained from patients requiring extractions for orthodontic purposes and collected from Tygerberg Oral Health Centre. A convenience sample method was used, where whenever an upper caries free premolar was extracted, the parent was asked if the tooth could be used for this study and consent was obtained. The crowns of the 15 teeth were cleaned and polished with pumice and rubber cups for 10 seconds (as the clinician would do prior to bracket cementation). The same 15 teeth were used with the seven different brands of brackets in order to establish a comparison of the adaptability of the brackets. The brackets were placed at a set orthodontic prescription of 4mm (measured from the slot area of the bracket to the tip of the buccal cusp of the tooth) on the upper first premolars. After bracket placement, the dontrix gauge was applied to the bracket to engage the slot area. The brackets were held in place with a constant force of 0.70 Newton (N) by the dontrix gauge. This allowed for reproducibility for the seven brackets with all fifteen teeth. In order to assess the space between the brackets and the teeth no adhesive was used. The space between the margins of the bracket and tooth interface was viewed under the Stereomicroscope (Carl Zeiss microscope, Zeiss Stemi508) at 50 times magnification. A two way mixed measures ANOVA was run to determine whether there were differences between the seven brackets placed at six points on the tooth surface. Results: GAC had the smallest overall mean measurement between bracket base and tooth surface followed by Ormco and Gemini respectively. Abzil had the largest overall mean measurement for the six points around the bracket

Classical immunoglobulin transgenic (Ig-Tg) mouse models such as the MD4 anti-hen egg lysozyme (-HEL) Ig-Tg line have been used extensively to study B cell responses in tolerance and immunity. This thesis describes a new generation of gene-targeted mice (designated SWHEL mice) whereby the VH10 Ig variable gene encoding the HyHEL-10 specificity of the original anti-HEL Ig-Tg mouse was targeted to the Ig heavy chain locus. B cells in the SWHEL mouse are therefore capable of undergoing class switch recombination (CSR) and somatic hypermutation (SHM), representing a major advance on the original MD4 mouse model. SWHEL mice were found to not only contain a large population of HEL-specific (HEL+) B cells but also a significant population of non-HEL-binding (HEL-) B cells generated by VH gene replacement. HEL+ SWHEL B cells were found to belong to the B2 lineage and displayed high levels of surface IgM. Nevertheless, they matured normally and colonised the primary B cell follicle and marginal zone (MZ) of the spleen. The SWHEL model thus provided an opportunity to re-examine some of the original observations made in the MD4 system and also to extend these observations, particularly with regard to the regulation of CSR by self-reactive B cells. As expected, analysis of SWHEL B cells exposed to high avidity membrane-bound HEL revealed that they underwent clonal deletion in the bone marrow (BM). More interestingly, analysis of HEL+ B cells exposed to low avidity soluble HEL revealed that they were able to emigrate from the BM to the spleen as anergic B cells. However, unlike anergic MD4 B cells, anergic SWHEL B cells were reduced in frequency, displayed an immature B cell phenotype, were excluded from the follicle and had a reduced lifespan. Direct measurement of B cell antigen receptor (BCR) occupancy by HEL and the frequency of HEL- competitor B cells was combined with mixed BM irradiation chimeras to demonstrate unequivocally that the difference in phenotype and fate of HEL+ B cells in the two systems was due solely to competition from HEL- B cells. In addition, the SWHEL model of B cell self-tolerance was used to show that while self-reactive B cells were hypo-responsive to BCR stimulation, BCR-independent signals delivered via anti-CD40 plus IL-4 or lipopolysaccharide could trigger them to undergo CSR and secretion of potentially pathogenic isotype-switched autoantibodies. Finally, the SWHEL model was used to study the responses of adoptively transferred follicular (Fo) and MZ B cells to in vivo activation with HEL conjugated to sheep red blood cells (HEL-SRBC). These studies revealed that both HEL+ MZ and Fo B cells were capable of mounting a robust T cell-dependent IgG1 antibody response to HEL-SRBC. However, HEL+ MZ B cells did not efficiently localise to the T cell-B cell border following antigen engagement and preferentially migrated to the bridging channels and red pulp. In contrast, HEL+ Fo B cells rapidly localised to the T cell-B cell border and subsequently colonised numerous germinal centres. As a result, the rate and pattern of SHM by HEL+ Fo and MZ B cells was shown to be distinct, with preferential targeting of mutations to the second complementarity-determining region in the former and to the second framework region in the latter. Together these data indicate illustrate the value of the SWHEL model and its potential to greatly advance the current understanding of B cell responses in tolerance and immunity.

Improved numerical reservoir models are constructed when all available diverse data sources are accounted for to the maximum extent possible. Integrating various diverse data is not a simple problem because data show different precision and relevance to the primary variables being modeled, nonlinear relations and different qualities. Previous approaches rely on a strong Gaussian assumption or the combination of the source-specific probabilities that are individually calibrated from each data source. This dissertation develops different approaches to integrate diverse earth science data. First approach is based on combining probability. Each of diverse data is calibrated to generate individual conditional probabilities, and they are combined by a combination model. Some existing models are reviewed and a combination model is proposed with a new weighting scheme. Weakness of the probability combination schemes (PCS) is addressed. Alternative to the PCS, this dissertation develops a multivariate analysis technique. The method models the multivariate distributions without a parametric distribution assumption and without ad-hoc probability combination procedures. The method accounts for nonlinear features and different types of the data. Once the multivariate distribution is modeled, the marginal distribution constraints are evaluated. A sequential iteration algorithm is proposed for the evaluation. The algorithm compares the extracted marginal distributions from the modeled multivariate distribution with the known marginal distributions and corrects the multivariate distribution. Ultimately, the corrected distribution satisfies all axioms of probability distribution functions as well as the complex features among the given data. The methodology is applied to several applications including: (1) integration of continuous data for a categorical attribute modeling, (2) integration of continuous and a discrete geologic map for categorical attribute modeling, (3) integration of continuous data for a continuous attribute modeling. Results are evaluated based on the defined criteria such as the fairness of the estimated probability or probability distribution and reasonable reproduction of input statistics. / Mining Engineering

Sammanfattning Denna magister uppsats undersöker huruvida ledarskap, ägarstruktur och kontroll påverkar svenska familjeföretags investerings prestation på marknaden. I undersökningen har 90 svenska företag analyserats inom en 15 års period (1990-2005). Ledarskap har delats upp i tre olika strukturer, den första strukturen står för grundar ledarskap. Regressionsanalysen i denna uppsats visade att en grundare har en positiv påverkan på företagets investerings prestation då grundaren agerade som Verkställande Direktör (VD), Styrelseordförande (SO) eller båda. Detta kan förklaras utifrån teorier som gör tydligt att en grundare äger entreprenörskaps anda och utmärkande kunskaper inom området ifråga. Resultatet för den andra strukturen, ättlings ledarskap visade att då ättlingar till grunderaren verkade som antingen VD, SO eller båda i företaget förekom en negativ påverkan på företagets finansiella prestation. Detta kan förklaras utifrån teorier som menar att en ättling inte har samma kunskap eller ambitioner som grundaren till företaget. Ättlingar har oftast ärvt högre poster inom företagen på grund av sina familjerelationer till grundaren snarare än på grund av sina kunskaper inom området. Den tredje ledarskapsstrukturen är externa ledare. Externa ledare är antingen en VD, SO eller båda som har blivit inhyrda till företaget av ägarfamiljen. Regressionsanalysen visade ett insignifikant resultat. När resultaten för ägarstruktur och andel röster av ägare analyserades i både företag med röstdifferensiering och utan röstdifferensiering visade det sig att när grundaren agerade som VD, SO eller båda i företag utan röstdifferensiering förekom ingen minoritets expropriation eller principal-agent konflikter inom företaget, vilket betyder att företagets finansiella prestation påverkades positivt. Liknande resultat hittades även för företag med röstdifferensiering som hade externa ledare i sin ledning.

This paper treats Corporate Social Responsibility as an investment in corporate reputation andas such aims at investigating the return of that investment. It does so partly by estimating theeffect of being perceived as socially responsible on the firm’s ability to maximize shareholdervalue and partly by estimating the effect on a more traditional accounting based measure offinancial performance. Results indicate that socially responsible firms are able to maximizeshareholder value to a greater extent than less responsible firms while at the same time notnecessarily performing better in traditional accounting terms.

The study examines to what extent weak labor unions and an abundance of labor have a negative effect on less developed countries terms of trade, as hypothesized by Hans Singer (1950) and Rául Prebisch (1950). Using a sample from panel data for 74 less developed countries during the period 1980 – 2010 in OLS-regressions with fixed effects, I find some evidence that weak labor unions and abundance of labor is negatively correlated with the terms of trade, which could be interpreted in favor of the Prebisch-Singer hypothesis. The marginal effect of an abundance of labor also appears to have less negative impact on the terms of trade as labor unions grow stronger.

No description available.

<p>Sammanfattning</p><p>Denna magister uppsats undersöker huruvida ledarskap, ägarstruktur och kontroll påverkar svenska familjeföretags investerings prestation på marknaden. I undersökningen har 90 svenska företag analyserats inom en 15 års period (1990-2005).</p><p>Ledarskap har delats upp i tre olika strukturer, den första strukturen står för grundar ledarskap. Regressionsanalysen i denna uppsats visade att en grundare har en positiv påverkan på företagets investerings prestation då grundaren agerade som Verkställande Direktör (VD), Styrelseordförande (SO) eller båda. Detta kan förklaras utifrån teorier som gör tydligt att en grundare äger entreprenörskaps anda och utmärkande kunskaper inom området ifråga. Resultatet för den andra strukturen, ättlings ledarskap visade att då ättlingar till grunderaren verkade som antingen VD, SO eller båda i företaget förekom en negativ påverkan på företagets finansiella prestation. Detta kan förklaras utifrån teorier som menar att en ättling inte har samma kunskap eller ambitioner som grundaren till företaget. Ättlingar har oftast ärvt högre poster inom företagen på grund av sina familjerelationer till grundaren snarare än på grund av sina kunskaper inom området. Den tredje ledarskapsstrukturen är externa ledare. Externa ledare är antingen en VD, SO eller båda som har blivit inhyrda till företaget av ägarfamiljen. Regressionsanalysen visade ett insignifikant resultat.</p><p>När resultaten för ägarstruktur och andel röster av ägare analyserades i både företag med röstdifferensiering och utan röstdifferensiering visade det sig att när grundaren agerade som VD, SO eller båda i företag utan röstdifferensiering förekom ingen minoritets expropriation eller principal-agent konflikter inom företaget, vilket betyder att företagets finansiella prestation påverkades positivt. Liknande resultat hittades även för företag med röstdifferensiering som hade externa ledare i sin ledning.</p>

This thesis proposes a new spatial multivariate count model to jointly analyze the traffic crash-related counts of pedestrians and bicyclists by injury severity. The modeling framework is applied to predict injury counts at a Census tract level, based on crash data from Manhattan, New York. The results highlight the need to use a multivariate modeling system for the analysis of injury counts by road-user type and injury severity level, while also accommodating spatial dependence effects in injury counts. / text