This thesis is about firm dynamics, and relates to the size and growth-rate distribution of firms. As such, it consists of an introductory and four separate chapters. The first chapter concerns the size distribution of firms, the two subsequent chapters deal more specically with high-growth firms (HGFs), and the last chapter covers a related topic in distributional estimation theory. The first three chapters are empirically oriented, whereas the fourth chapter develops a statistical concept. / <p>QC 20130215</p>

Body size varies according to nutritional availability, which is of ecological and evolutionary relevance. The purpose of this study is to test the hypothesis that differences in adult body size are realized by increasing juvenile growth rate for white-tailed deer (Odocoileus virginianus). Harvest records are used to construct growth rate estimates by empirical nonlinear curve fitting. Results are compared to those of previous models that include additional parameters. The rate of growth increases during the study period. Models that estimate multiple parameters may not work with harvest data in which estimates of these parameters are prone to error, which renders estimates from complex models too variable to detect inter-annual changes in growth rate that this simpler model captures

The effect of cytokinin and gibberellin, and in particular a combination of the two, on termination of dormant potato tubers was investigated. The objective was to effectively terminate dormancy through the external application of a combination of cytokinin and gibberellin. Freshly harvested tubers were treated and either cut at the stolon end with the apical portions placed on moist cotton wool, or left intact and dry. Tuber segments treated with a high concentration of cytokinin (0.1g.Lˉ¹) or a combination of cytokinin and gibberellin sprouted within 5 days, whereas high gibberellin concentrations (0.1g.Lˉ¹) stimulated sprouting within 9 days. Untreated tuber segments supplied only with moisture terminated dormancy later than hormonal treated tubers, but much earlier than segments that were kept dry. Tuber segments treated with a combination of cytokinin and gibberellin, or a high concentration of gibberellin (0.1g.Lˉ¹), produced more and longer sprouts than tubers treated with only cytokinin (0.1g.Lˉ¹) or a low concentration of gibberellin (0.005g.Lˉ¹). Sprouts on tuber segments treated with a combination of cytokinin and gibberellin attained maximum sprout growth rate nine days after treatment, but thereafter the growth rate decreased. This decrease may be a consequence of closed plasmodesmata although membrane permeability and its affect on assimilate availability may play a role. This phenomenon deserves further research attention. Removal of wound periderm did not reactivate sprout growth. The wounding of tubers by removing a portion at the stolon end and supplying moisture greatly enhanced the termination of dormancy and subsequent sprout growth, indicating that the availability of water may be a factor in initiation of sprouts. The results are compatible with the hypothesis that cells in dormant buds are arrested in the G1 phase of the cell cycle. Cytokinin is needed to initiate cell cycling, but gibberellin is also needed to initiate and maintain cell growth. These two growth regulators are also involved in the opening of the plasmodesmata as well as the creation of new plasmodesmata witch would establish communication between the apical meristem and the rest of the tuber. / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Plant Production and Soil Science / unrestricted

No description available.

<p>Offshore spring zooplankton biomass in northern Lake Michigan is currently dominated by calanoid copepods and lacking in cyclopoid copepod biomass, which is a preferred prey type for larval coregonids in the Great Lakes. As such, we survey nearshore beach zooplankton to determine if nearshore environments are following offshore trends and describe larval coregonid diets and prey selectivity during spring 2015-2019. Copepod nauplii and calanoid copepods were the most abundant prey types in the nearshore beach environments, and although larvae did not consume copepod nauplii, larvae did incorporate substantial later life stages of calanoid copepods into their diet. Additionally, larvae exhibited positive selectivity for both calanoid and cyclopoid copepods. High consumption of and selectivity for calanoid copepods in small larval coregonids is not a common observation in the Great Lakes, as previous diets of small larvae have been comprised of mainly cyclopoid copepods and cladocerans. Future research into the foraging costs and nutritional benefits of larval diets with differing ratios of cyclopoid to calanoid biomass should be investigated to understand the potential impacts of differing diets on larval growth and survival. </p> <p> Many species of larval fish in Lakes Michigan and Huron experience a prolonged offshore pelagic stage as during early life, but environmental conditions in offshore environments have changed in the past quarter century. Under current conditions, offshore habitats may be unsuitable for larval fish, given recent increases in offshore water clarity and decreases in offshore primary production and zooplankton biomass in both lakes. To evaluate habitat suitability for larval fish, we characterized ambient environmental conditions using data streams from multiple high frequency sensors to develop growth rate potential models as an index of habitat quality of nearshore-offshore transects in central Lake Michigan and southern Lake Huron. Since temperature regimes differ throughout the summer, we compare habitat quality throughout the summer for larval yellow perch and smelt, two species that have demonstrated offshore pelagic stages as larvae. Early in the summer, high habitat quality was concentrated nearshore, while later in the summer high habitat quality was concentrated near the thermocline, at depths where larvae are unlikely to inhabit due to limited swimming ability. The offshore (15-60 m depth contour) surface waters of both lakes provide poor habitat quality in May and July, although the surface waters of transects collected during June in southern Lake Huron provided high quality habitat at all distances from shore. These results suggest that offshore advection and prolonged offshore pelagic stage duration during early life of fish could contribute to decreased growth and survival of larval fish in lakes Michigan and Huron. </p>

Warren Buffet started an investment partnership of $100 in 1956 and has gone on to accumulate a personal net worth of over $60 billion. He started primarily as a value investor, and gradually changed over time to a strategy which uses the PEG ratio as its main tool. Peter Lynch, one of the most successful fund managers in history and had a compound annual growth rate of 29% for 13 years, was the man to first introduce the world to the PEG ratio. With such prominence, however, widespread use of previously successful strategies tend to render them ineffective due to everyone using them, and today the PEG ratio’s effectiveness as a valuation tool remains a topical debate between market commentators.This study sets out to determine if the PEG ratio adds value using JSE Main Board data from 2002 to 2012. Returns from five portfolios constructed directly from share quintiles based on PEG ratio magnitude are compared to returns of a portfolio constructed from the optimum quintile of value shares. The PEG ratio portfolio returns are examined based on 3 rebalancing period strategies, and on relative performance between the quintiles within each strategy.It is found that a 24 monthly rebalancing strategy provides superior returns to that of 3 or 12 monthly rebalancing for PEG quintiles of selected stocks. Furthermore, the lowest PEG ratio quintile in this strategy outperforms the value portfolio by a compound annual growth rate of 4.3%. The second lowest PEG ratio quintile portfolio performs slightly better to ensure that 40% of stocks selected based on the PEG ratio produced sustained superior returns to the optimum quintile value portfolio. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

In this master thesis the influence from process parameters within the Chemical vapour deposition process for a Zirconium Carbon-Nitride coating was investigated regarding growth rate, microstructure and texture. The interest in utilizing Zirconium Carbon-Nitride (Zr(C,N)) is due to its low coefficient of thermal expansion (CTE) relative the currently commonly used wear resistant coatings of Titanium-Carbon-Nitride (Ti(C,N)). The process parameters studied in this work is the ratio of the partial pressures of Zirconium tetrachloride over Acetonitrile (ZrCl4/CH3CN), addition of Nitrogen respectively hydrochloric acid, partial pressures of the precursors, reactor temperature and total gas flow. By controlling these process parameters one can control the grain size, growth rate within the reactor and texture of the Zr(C,N) coating deposited.

Elemental stoichiometry defines a critical understanding of the relationship between nutrient availability and usage throughout different levels of the biological community. We found there is a link between available phosphorus (P), cellular phosphorus, and nematode development as postulated by the growth rate hypothesis (GRH). I predicted that in a P-poor environment, cellular RNA concentrations would be lower than they are in P-rich environment, and thus the 18s rRNA expression level will have reduced. To most efficiently regulate the uptake of limited P, I predicted that nematodes in P-poor environments would decrease the number of copies of the 18s rRNA gene in their genome. I measured life history traits as well as rRNA gene expression and gene copy number. We found that elemental stoichiometry predicts evolutionary changes consistent with the Growth Rate Hypothesis. We sequenced and assembled a draft genome of P. murrayi. Although we expected to find genes responsible for stress tolerance, we hypothesized that in response to strong selection pressure associated with living in a simplified ecosystem, over time the genome of P. murrayi should have undergone significant decay (gene loss) relative to species in ecosystems structured more strongly by biotic interactions. We found significantly fewer genes in P. murrayi. To compare patterns of gene expression between two highly divergent Antarctic nematode species, we sequenced and assembled the transcriptomes of S. lindsayae and P. murrayi. Under laboratory conditions at 4˚C, S. lindsayae had significantly lower rates of gene expression but expressed a significantly larger number of genes. We speculate that the differences in gene expression are correlated with life history traits (developmental rates) while the differences in the number of genes expressed can be explained by their different genetic systems (S. lindsayae is amphimictic, P. murrayi is parthenogenic) and the soil environments to which they are adapted. Since we previously showed that differences in available P content can influence the evolution of gene expression via gene copy number, and that this ultimately influences growth rate, we wondered how much of this response is driven by genetics versus how strongly these patterns are driven by temperature. To better understand this, we maintained wild type populations of P. murrayi in P-rich and P-poor conditions at 5˚C, 10˚C and 15˚C in the laboratory for over 40 generations and sequenced the transcriptomes prepared from each treatment group. We found that nutrient levels played an important role in gene expression when the temperature is optimal for P. murrayi culturing and that temperature is more important in gene expression when the available P is limited. This work underscores the utility of using principles of elemental stoichiometry coupled with genomic and transcriptomics research tools to make and test predictions about life history evolution. The results of my work also inform inferences about the ways in which nutrient availability also drives the organization of trophic interactions and ultimately ecosystems.

Bakgrund: Kraven på Corporate Social Responsibility i företag ökar till följd av ökad medvetenhet i samhället. Högst är påtryckningarna på stora företag, men det innebär inte att små- och medelstora företag inte ställs inför krav. Utmaningar med implementering av CSR har dock en tendens att påverka mindre företag mer. Eftersom gasellföretag är mindre företag som dessutom karaktäriseras av en otroligt snabb tillväxttakt har det väckt ett intresse att studera hur dessa typer av företag upplever krav kring CSR samt hur de arbetar med detta. Syfte: Syftet med denna studie är att undersöka om gasellföretag engagerar sig i CSR-aktiviteter och i sådana fall i vilken utsträckning. Vidare är syftet att öka förståelsen kring hur en snabb tillväxttakt kan komma att påverka ett företags CSR-arbete i en sådan föränderlig omvärld och vad det huvudsakliga syftet bakom ett sådant engagemang är. Metod: Studien utgår från ett hermeneutiskt perspektiv med en induktiv ansats. Datainsamlingen är gjord genom en kvalitativ flerfallstudie där fem gasellföretag har intervjuats. Detta har kompletterats med olika dokument i form av hållbarhetsredovisningar och företagens hemsidor. Slutsats: Studien visar att gasellföretag arbetar med CSR, men i olika utsträckning. Storleken på engagemanget beror främst på ett personligt engagemang och en vilja från ledningsnivå. Den snabba tillväxttakten gör att det kan vara svårt att ägna tid och pengar till ett integrerat CSR-arbete. Studien visar dock att det är väsentligt att börja sitt CSR-arbete redan från start för att sedan låta det växa med storleken av företaget. / Background: The demand on Corporate Social Responsibility in corporations is increasing due to increased awareness in society. The pressure is especially high on large corporations, but this does not mean that the pressure on small and medium enterprises is non-existing. However, challenges with implementation of CSR tends to affect smaller companies more. Since gazelles are smaller companies with an extraordinary high growth rate, it is interesting to study how these types of companies experience the demand on CSR and how they approach this. Purpose: The purpose of this study is to examine whether gazelles engage in CSR and to which extend. Furthermore, the purpose is to increase the understanding as to how a high growth rate can affect a company’s CSR-work in such a changing world and what the main purpose is behind such an engagement. Research Method: This study rest on a hermeneutic perspective with an inductive approach. The data collection has been conducted through a qualitative multiple case study where five different gazelles have been interviewed. These interviews have been supplemented with document studies in terms of each company’s website and sustainability report. Conclusion: The study shows that gazelles engage in CSR, but to which extend varies. The size of the engagement mainly depends on a personal engagement and a will from top management. The high growth rate makes it difficult to dedicate time and money to integrate CSR in the organization. However, the study shows that it is substantial to begin the CSR-work from the start to let it grow in the same pace as the company.

Kochia scoparia (L.) Schrad. has had limited use as a forage crop during the past fifteen. years in parts of the western United States, Canada, and Argentina. Erickson and Moxon (1947) reported kochia* to be a good emergency feed for sheep and cattle during dry years in South Dakota. Salguero (1946) said that this species could be utilized in Argentina as silage or pasturage if harvested before flowering. Bell, et al. (1952) in Saskatoon, Canada studied this species in a comparison with other introduced plants and reported that it seemed to have desirable nutrient characteristics for livestock roughage. Plummer (1949) reported beef cattle in Ephraim, Utah had eaten and gained normally on kochia hay.