O efeito da diversificação no valor das empresas: um estudo do caso brasileiro

Nesta dissertação, mostramos evidências de que a diversificação e o valor das empresas aparentam ser negativamente correlacionados. Esta relação é observada para diferentes métricas de diversificação e se mantém mesmo quando controlamos o efeito de outras variáveis conhecidas por influenciar o valor das empresas. Nossa análise não conseguiu comprovar de forma robusta se o efeito negativo causado pela diversificação diminui na medida em que esta se dá em segmentos mais relacionados. No entanto há indícios de que esta hipótese seja de fato verdadeira Um resultado interessante observado foi que assim como empresas especializadas, as empresas altamente diversificadas também possuem uma alta percepção de valor. Mostramos que a relação entre valor e diversificação possui o perfil de uma curva côncava com um ponto de mínimo justamente no nível de diversificação intermediário. Por fim, observamos que o efeito da diversificação no valor das empresas nos anos de 2008 e 2007 passou a ser positivo. O que nos sugere que em tempos de crise econômica, a percepção do valor de empresas mais diversificadas aumenta de forma significativa.

Effect of family relatedness on characteristics of estimated IBD probabilities in relation to precision of QTL estimates

Background: A random QTL effects model uses a function of probabilities that two alleles in the same or in different animals at a particular genomic position are identical by descent (IBD). Estimates of such IBD probabilities and therefore, modeling and estimating QTL variances, depend on marker polymorphism, strength of linkage and linkage disequilibrium of markers and QTL, and the relatedness of animals in the pedigree. The effect of relatedness of animals in a pedigree on IBD probabilities and their characteristics was examined in a simulation study. Results: The study based on nine multi-generational family structures, similar to a pedigree structure of a real dairy population, distinguished by an increased level of inbreeding from zero to 28 % across the studied population. Highest inbreeding level in the pedigree, connected with highest relatedness, was accompanied by highest IBD probabilities of two alleles at the same locus, and by lower relative variation coefficients. Profiles of correlation coefficients of IBD probabilities along the marked chromosomal segment with those at the true QTL position were steepest when the inbreeding coefficient in the pedigree was highest. Precision of estimated QTL location increased with increasing inbreeding and pedigree relatedness. A method to assess the optimum level of inbreeding for QTL detection is proposed, depending on population parameters. Conclusions: An increased overall relationship in a QTL mapping design has positive effects on precision of QTL position estimates. But the relationship of inbreeding level and the capacity for QTL detection depending on the recombination rate of QTL and adjacent informative marker is not linear. © 2010 Freyer et al., licensee BioMed Central Ltd.

Venture idea newness, relatedness and performance in nascent ventures

Principal Topic The study of the origin and characteristics of venture ideas - or ''opportunities'' as they are often called - and their contextual fit are key research goals in entrepreneurship (Davidsson, 2004). We define venture idea as ''the core ideas of an entrepreneur about what to sell, how to sell, whom to sell and how an entrepreneur acquire or produce the product or service which he/she sells'' for the purpose of this study. When realized the venture idea becomes a ''business model''. Even though venture ideas are central to entrepreneurship yet its characteristics and their effect to the entrepreneurial process is mysterious. According to Schumpeter (1934) entrepreneurs could creatively destruct the existing market condition by introducing new product/service, new production methods, new markets, and new sources of supply and reorganization of industries. The introduction, development and use of new ideas are generally called as ''innovation'' (Damanpour & Wischnevsky, 2006) and ''newness'' is a property of innovation and is a relative term which means that the degree of unfamiliarity of venture idea either to a firm or to a market. However Schumpeter's (1934) discusses five different types of newness, indicating that type of newness is an important issue. More recently, Shane and Venkataraman (2000) called for research taking into consideration not only the variation of characteristics of individuals but also heterogeneity of venture ideas, Empirically, Samuelson (2001, 2004) investigated process differences between innovative venture ideas and imitative venture ideas. However, he used only a crude dichotomy regarding the venture idea newness. According to Davidsson, (2004) as entrepreneurs could introduce new economic activities ranging from pure imitation to being new to the entire world market, highlighting that newness is a matter of degree. Dahlqvist (2007) examined the venture idea newness and made and attempt at more refined assessment of the degree and type of newness of venture idea. Building on these predecessors our study refines the assessment of venture idea newness by measuring the degree of venture idea newness (new to the world, new to the market, substantially improved while not entirely new, and imitation) for four different types of newness (product/service, method of production, method of promotion, and customer/target market). We then related type and degree of newness to the pace of progress in nascent venturing process. We hypothesize that newness will slow down the business creation process. Shane & Venkataraman (2000) introduced entrepreneurship as the nexus of opportunities and individuals. In line with this some scholars has investigated the relationship between individuals and opportunities. For example Shane (2000) investigates the relatedness between individuals' prior knowledge and identification of opportunities. Shepherd & DeTinne (2005) identified that there is a positive relationship between potential financial reward and the identification of innovative venture ideas. Sarasvathy's 'Effectuation Theory'' assumes high degree of relatedness with founders' skills, knowledge and resources in the selection of venture ideas. However entrepreneurship literature is scant with analyses of how this relatedness affects to the progress of venturing process. Therefore, we assess the venture ideas' degree of relatedness to prior knowledge and resources, and relate these, too, to the pace of progress in nascent venturing process. We hypothesize that relatedness will increase the speed of business creation. Methodology For this study we will compare early findings from data collected through the Comprehensive Australian Study of Entrepreneurial Emergence (CAUSEE). CAUSEE is a longitudinal study whose primary objective is to uncover the factors that initiate, hinder and facilitate the process of emergence and development of new firms. Data were collected from a representative sample of some 30,000 households in Australia using random digit dialing (RDD) telephone survey interviews. Through the first round of data collection identified 600 entrepreneurs who are currently involved in the business start-up process. The unit of the analysis is the emerging venture, with the respondent acting as its spokesperson. The study methodology allows researchers to identify ventures in early stages of creation and to longitudinally follow their progression through data collection periods over time. Our measures of newness build on previous work by Dahlqvist (2007). Our adapted version was developed over two pre-tests with about 80 participants in each. The measures of relatedness were developed through the two rounds of pre-testing. The pace of progress in the venture creation process is assessed with the help of time-stamped gestation activities; a technique developed in the Panel Study of Entrepreneurial Dynamics (PSED). Results and Implications We hypothesized that venture idea newness slows down the venturing process whereas relatedness facilitates the venturing process. Results of 600 nascent entrepreneurs in Australia indicated that there is marginal support for the hypothesis that relatedness assists the gestation progress. Newness is significant but is the opposite sign to the hypothesized. The results give number of implications for researchers, business founders, consultants and policy makers in terms of better knowledge of the venture creation process.

Effect of inaccuracies in anthropometric data and linked-segment inverse dynamic modeling on kinetics of gait in persons with partial foot amputation

The accuracy of data derived from linked-segment models depends on how well the system has been represented. Previous investigations describing the gait of persons with partial foot amputation did not account for the unique anthropometry of the residuum or the inclusion of a prosthesis and footwear in the model and, as such, are likely to have underestimated the magnitude of the peak joint moments and powers. This investigation determined the effect of inaccuracies in the anthropometric input data on the kinetics of gait. Toward this end, a geometric model was developed and validated to estimate body segment parameters of various intact and partial feet. These data were then incorporated into customized linked-segment models, and the kinetic data were compared with that obtained from conventional models. Results indicate that accurate modeling increased the magnitude of the peak hip and knee joint moments and powers during terminal swing. Conventional inverse dynamic models are sufficiently accurate for research questions relating to stance phase. More accurate models that account for the anthropometry of the residuum, prosthesis, and footwear better reflect the work of the hip extensors and knee flexors to decelerate the limb during terminal swing phase.

A critical analysis of sperm donation practices : the personal and social effects of disrupting the unity of biological and social relatedness for the offspring

This thesis critically analyses sperm donation practices from a child-centred perspective. It examines the effects, both personal and social, of disrupting the unity of biological and social relatedness in families affected by donor conception. It examines how disruption is facilitated by a process of mediation which is detailed using a model provided by Sunderland (2002). This model identifies mediating movements - alienation, translation, re-contextualisation and absorption - which help to explain the powerful and dominating material, and social and political processes which occur in biotechnology, or in reproductive technology in this case. The understanding of such movements and mediation of meanings is inspired by the complementary work of Silverstone (1999) and Sunderland. This model allows for a more critical appreciation of the movement of meaning from previously inalienable aspects of life to alienable products through biotechnology (Sunderland, 2002). Once this mediation in donor conception is subjected to critical examination here, it is then approached from different angles of investigation. The thesis posits that two conflicting notions of the self are being applied to fertility-frustrated adults and the offspring of reproductive interventions. Adults using reproductive interventions receive support to maximise their genetic continuity, but in so doing they create and dismiss the corresponding genetic discontinuity produced for the offspring. The offspring’s kinship and identity are then framed through an experimental postmodernist notion, presenting them as social rather than innate constructs. The adults using the reproductive intervention, on the other hand, have their identity and kinship continuity framed and supported as normative, innate, and based on genetic connection. This use of shifting frameworks is presented as unjust and harmful, creating double standards and a corrosion of kinship values, connection and intelligibility between generations; indeed, it is put forward as adult-centric. The analysis of other forms of human kinship dislocation provided by this thesis explores an under-utilised resource which is used to counter the commonly held opinion that any disruption of social and genetic relatedness for donor offspring is insignificant. The experiences of adoption and the stolen generations are used to inform understanding of the personal and social effects of such kinship disruption and potential reunion for donor offspring. These examples, along with laws governing international human rights, further strengthen the appeal here for normative principles and protections based on collective knowledge and standards to be applied to children of reproductive technology. The thesis presents the argument that the framing and regulation of reproductive technology is excessively influenced by industry providers and users. The interests of these parties collide with and corrode any accurate assessments and protections afforded to the children of reproductive technology. The thesis seeks to counter such encroachments and concludes by presenting these protections, frameworks, and human experiences as resources which can help to address the problems created for the offspring of such reproductive interventions, thereby illustrating why these reproductive interventions should be discontinued.

Attractiveness of venture ideas : a conjoint study

Principal Topic : According to Shane & Venkataraman (2000) entrepreneurship consists of the recognition and exploitation of venture ideas - or opportunities as they often called - to create future goods and services. This definition puts venture ideas is at the heart of entrepreneurship research. Substantial research has been done on venture ideas in order to enhance our understanding of this phenomenon (e.g. Choi & Shepherd, 2004; Shane, 2000; Shepherd & DeTienne, 2005). However, we are yet to learn what factors drive entrepreneurs' perceptions of the relative attractiveness of venture ideas, and how important different idea characteristics are for such assessments. Ruef (2002) recognized that there is an uneven distribution of venture ideas undertaken by entrepreneurs in the USA. A majority introduce either a new product/service or access a new market or market segment. A smaller percentage of entrepreneurs introduce a new method of production, organizing, or distribution. This implies that some forms of venture ideas are perceived by entrepreneurs as more important or valuable than others. However, Ruef does not provide any information regarding why some forms of venture ideas are more common than others among entrepreneurs. Therefore, this study empirically investigates what factors affect the attractiveness of venture ideas as well as their relative importance. Based on two key characteristics of venture ideas, namely venture idea newness and relatedness, our study investigates how different types and degrees of newness and relatedness of venture ideas affect their attractiveness as perceived by expert entrepreneurs. Methodology/Key : Propositions According to Schumpeter (1934) entrepreneurs introduce different types of venture ideas such as new products/services, new method of production, enter into new markets/customer and new method of promotion. Further, according to Schumpeter (1934) and Kirzner (1973) venture ideas introduced to the market range along a continuum of innovative to imitative ideas. The distinction between these two extremes of venture idea highlights an important property of venture idea, namely their newness. Entrepreneurs, in order to gain competitive advantage or above average returns introduce their venture ideas which may be either new to the world, new to the market that they seek to enter, substantially improved from current offerings and an imitative form of existing offerings. Expert entrepreneurs may be more attracted to venture ideas that exhibit high degree of newness because of the higher newness is coupled with increased market potential (Drucker, 1985) Moreover, certain individual characteristics also affect the attractiveness of venture idea. According to Shane (2000), individual's prior knowledge is closely associated with the recognition of venture ideas. Sarasvathy's (2001) Effectuation theory proposes a high degree of relatedness between venture ideas and the resource position of the individual. Thus, entrepreneurs may be more attracted to venture ideas that are closely aligned with the knowledge and/or resources they already possess. On the other hand, the potential financial gain (Shepherd & DeTienne, 2005) may be larger for ideas that are not close to the entrepreneurs' home turf. Therefore, potential financial gain is a stimulus that has to be considered separately. We aim to examine how entrepreneurs weigh considerations of different forms of newness and relatedness as well as potential financial gain in assessing the attractiveness of venture ideas. We use conjoint analysis to determine how expert entrepreneurs develop preferences for venture ideas which involved with different degrees of newness, relatedness and potential gain. This analytical method paves way to measure the trade-offs they make when choosing a particular venture idea. The conjoint analysis estimates respondents' preferences in terms of utilities (or part-worth) for each level of newness, relatedness and potential gain of venture ideas. A sample of 50 expert entrepreneurs who were awarded young entrepreneurship awards in Sri Lanka in 2007 is used for interviews. Each respondent is interviewed providing with 32 scenarios which explicate different combinations of possible profiles open them into consideration. Conjoint software (SPSS) is used to analyse data. Results and Implications : The data collection of this study is still underway. However, results of this study will provide information regarding the attractiveness of each level of newness, relatedness and potential gain of venture idea and their relative importance in a business model. Additionally, these results provide important implications for entrepreneurs, consultants and other stakeholders as regards the importance of different of attributes of venture idea coupled with different levels. Entrepreneurs, consultants and other stakeholders could make decisions accordingly.

The role of idea novelty and relatedness in nascent ventures

The study of venture idea characteristics and the contextual fit between venture ideas and individuals are key research goals in entrepreneurship (Davidsson, 2004). However, to date there has been limited scholarly attention given to these phenomena. Accordingly, this study aims to help fill the gap by investigating the importance of novelty and relatedness of venture ideas in entrepreneurial firms. On the premise that new venture creation is a process and that research should be focused on the early stages of the venturing process, this study primarily focuses its attention on examining how venture idea novelty and relatedness affect the performance in the venture creation process. Different types and degrees of novelty are considered here. Relatedness is shown to be based on individuals’ prior knowledge and resource endowment. Performance in the venture creation process is evaluated according to four possible outcomes: making progress, getting operational, being terminated and achieving positive cash flow. A theoretical model is developed demonstrating the relationship between these variables along with the investment of time and money. Several hypotheses are developed to be tested. Among them, it is hypothesised that novelty hinders short term performance in the venture creation process. On the other hand knowledge and resource relatedness are hypothesised to promote performance. An experimental study was required in order to understand how different types and degrees of novelty and relatedness of venture ideas affect the attractiveness of venture ideas in the eyes of experienced entrepreneurs. Thus, the empirical work in this thesis was based on two separate studies. In the first one, a conjoint analysis experiment was conducted on 32 experienced entrepreneurs in order to ascertain attitudinal preferences regarding venture idea attractiveness based on novelty, relatedness and potential financial gains. This helped to estimate utility values for different levels of different attributes of venture ideas and their relative importance in the attractiveness. The second study was a longitudinal investigation of how venture idea novelty and relatedness affect the performance in the venture creation process. The data for this study is from the Comprehensive Australian Study for Entrepreneurial Emergence (CAUSEE) project that has been established in order to explore the new venture creation process in Australia. CAUSEE collects data from a representative sample of over 30,000 households in Australia using random digit dialling (RDD) telephone interviews. From these cases, data was collected at two points in time during a 12 month period from 493 firms, who are currently involved in the start-up process. Hypotheses were tested and inferences were derived through descriptive statistics, confirmatory factor analysis and structural equation modelling. Results of study 1 indicate that venture idea characteristics have a role in the attractiveness and entrepreneurs prefer to introduce a moderate degree of novelty across all types of venture ideas concerned. Knowledge relatedness is demonstrated to be a more significant factor in attractiveness than resource relatedness. Results of study 2 show that the novelty hinders nascent venture performance. On the other hand, resource relatedness has a positive impact on performance unlike knowledge relatedness which has none. The results of these studies have important implications for potential entrepreneurs, investors, researchers, consultants etc. by developing a better understanding in the venture creation process and its success factors in terms of both theory and practice.

The reliability, accuracy and minimal detectable difference of a multi-segment kinematic model of the foot-shoe complex

Kinematic models are commonly used to quantify foot and ankle kinematics, yet no marker sets or models have been proven reliable or accurate when wearing shoes. Further, the minimal detectable difference of a developed model is often not reported. We present a kinematic model that is reliable, accurate and sensitive to describe the kinematics of the foot–shoe complex and lower leg during walking gait. In order to achieve this, a new marker set was established, consisting of 25 markers applied on the shoe and skin surface, which informed a four segment kinematic model of the foot–shoe complex and lower leg. Three independent experiments were conducted to determine the reliability, accuracy and minimal detectable difference of the marker set and model. Inter-rater reliability of marker placement on the shoe was proven to be good to excellent (ICC = 0.75–0.98) indicating that markers could be applied reliably between raters. Intra-rater reliability was better for the experienced rater (ICC = 0.68–0.99) than the inexperienced rater (ICC = 0.38–0.97). The accuracy of marker placement along each axis was <6.7 mm for all markers studied. Minimal detectable difference (MDD90) thresholds were defined for each joint; tibiocalcaneal joint – MDD90 = 2.17–9.36°, tarsometatarsal joint – MDD90 = 1.03–9.29° and the metatarsophalangeal joint – MDD90 = 1.75–9.12°. These thresholds proposed are specific for the description of shod motion, and can be used in future research designed at comparing between different footwear.

The development of a multi-segment kinematic model of footwear

In gait analysis, both shoe mounted and skin mounted markers have been used to quantify the movement of the foot inside the shoe. However, these models have not been demonstrated as reliable or accurate in shod conditions. The purpose of this study was to develop an accurate and reliable marker set to describe foot-shoe complex kinematics during stance phase.

Pedigree-free animal models : the relatedness matrix reloaded

Animal models typically require a known genetic pedigree to estimate quantitative genetic parameters. Here we test whether animal models can alternatively be based on estimates of relatedness derived entirely from molecular marker data. Our case study is the morphology of a wild bird population, for which we report estimates of the genetic variance-covariance matrices (G) of six morphological traits using three methods: the traditional animal model; a molecular marker-based approach to estimate heritability based on Ritland's pairwise regression method; and a new approach using a molecular genealogy arranged in a relatedness matrix (R) to replace the pedigree in an animal model. Using the traditional animal model, we found significant genetic variance for all six traits and positive genetic covariance among traits. The pairwise regression method did not return reliable estimates of quantitative genetic parameters in this population, with estimates of genetic variance and covariance typically being very small or negative. In contrast, we found mixed evidence for the use of the pedigree-free animal model. Similar to the pairwise regression method, the pedigree-free approach performed poorly when the full-rank R matrix based on the molecular genealogy was employed. However, performance improved substantially when we reduced the dimensionality of the R matrix in order to maximize the signal to noise ratio. Using reduced-rank R matrices generated estimates of genetic variance that were much closer to those from the traditional model. Nevertheless, this method was less reliable at estimating covariances, which were often estimated to be negative. Taken together, these results suggest that pedigree-free animal models can recover quantitative genetic information, although the signal remains relatively weak. It remains to be determined whether this problem can be overcome by the use of a more powerful battery of molecular markers and improved methods for reconstructing genealogies.

The effect of testing protocol on immature bovine thoracic spine segment stiffness

Introduction. In vitro spine biomechanical testing has been central to many advances in understanding the physiology and pathology of the human spine. Owing to the difficulty in obtaining sufficient numbers of human samples to conduct these studies, animal spines have been accepted as a substitute model. However, it is difficult to compare results from different studies, as they use different preparation, testing and data collection methods. The aim of this study was to identify the effect of repeated cyclic loading on bovine spine segment stiffness. It also aimed to quantify the effect of multiple freeze-thaw sequences, as many tests would be difficult to complete in a single session [1-3]. Materials and Methods. Thoracic spines from 6-8 week old calves were used. Each spine was dissected and divided into motion segments including levels T4-T11 (n=28). These were divided into two equal groups. Each segment was potted in polymethylemethacrylate. An Instron Biaxial materials testing machine with a custom made jig was used for testing. The segments were tested in flexion/extension, lateral bending and axial rotation at 37 degrees C and 100% humidity, using moment control to a maximum plus/minus 1.75 Nm with a loading rate of 0.3 Nm per second. Group (A) were tested with continuous repeated cyclic loading for 500 cycles with data recorded at cycles 3, 5, 10, 25, 100, 200, 300, 400 and 500. Group (B) were tested with 10 load cycles after each of 5 freeze thaw sequences. Data was collected from the tenth load cycle after each sequence. Statistical analysis of the data was performed using paired samples t-tests, ANOVA and generalized estimating equations. Results. The data were confirmed as having a normal distribution. 1. There were significant reductions in mean stiffness in flexion/extension (-20%; P=0.001) and lateral bending (-17%; P=0.009) over the 500 load cycles. However, there was no statistically significant change in axial rotation (P=0.152) 2. There was no statistically significant difference between mean stiffness over the five freeze-thaw sequences in flexion/extension (p=0.879) and axial rotation (p=0.07). However, there was a significant reduction in stiffness in lateral bending (-26%; p=0.007) Conclusion. Biomechanical testing of immature bovine spine motion segments requires careful interpretation. The effect of the number of load cycles as well as the number of freeze-thaw cycles on the stiffness of the motion segments depends on the axis of main movement.