Empresas startups: análise do ciclo de vida a partir do modelo de Lester, Parnell e Carraher (2003)

Objective of the study: This research seeks to analyze which stages of the organizational life cycle (CVO) model proposed by Lester, Parnell and Carraher (2003) are relevant to Brazilian startups, aiming to: (i) identify the existing CVO stages in startups and ( ii) present strategic recommendations for each stage. Methodology / approach: This is a research with a descriptive, non-parametric approach, using a Likert-type scale through a scale validated in previous research, plus sociodemographic variables. Collected data were analyzed according to the method proposed by Frezatti et al. (2010), which states that the questions included in the questionnaire are related to the different stages of the life cycle of the model proposed by Lester, Parnell and Carraher (2003). Originality / Relevance: Several authors have written about CVO, focusing their research on small or large companies, as well as family businesses. A specific CVO model for startups has not been found, according to a bibliographic research carried out as part of the theoretical framework of this study. Main results: 118 valid responses were obtained. The analysis of the results indicated that not all the existing stages in the CVO theoretical model research existed in the sample of startups investigated. The stages of birth, growth and decline were identified and, based on these findings, recommendations for possible strategies were made in each stage. Theoretical / methodological contributions: The results obtained from this research can be applied to startups seeking longevity, from the understanding of their life cycle and possible strategies pertinent to each identified phase.Objetivo del trabajo: Este estudio busca identificar las etapas del modelo de ciclo de vida organizacional (CVO) de Lester, Parnell y Carraher (2003), que son relevantes en las startups brasileñas y tienen como objetivo: (i) identificar las etapas del CVO existentes en startups y (ii) presentar recomendaciones estratégicas para cada etapa.Metodología / enfoque: Se trata de una investigación con enfoque descriptivo, no paramétrico, siendo utilizada la escala del tipo likert de cuestionario ya validado en investigaciones anteriores, más las preguntas sociodemográficas. Se obtuvieron 118 respuestas válidas. Los datos fueron analizados según el método de análisis propuesto por Frezatti et al. (2010) que preconizan que las cuestiones incluidas en el cuestionario tienen relación con las etapas del ciclo de vida del modelo de Lester, Parnell y Carraher (2003).Originalidad/Pertinencia: Diversos autores escribieron sobre el CVO, volviendo su investigación para pequeñas o grandes empresas, empresas familiares, pero no se encontró un modelo de CVO específico para startups, conforme la investigación bibliográfica realizada como parte de la investigación teórica de este estudio.Principales resultados: Con el análisis de los resultados se percibió que no todas las etapas existentes en el modelo teórico utilizado como base para la investigación de campo existían en la muestra de startups investigada. Se identificaron las etapas de nacimiento, crecimiento y decadencia y, a partir de tal constatación, foram recomendadas estrategias posibles en cada una de las etapas.Contribuciones teóricas/metodológicas: Los resultados obtenidos con esta investigación pueden ser aplicados por startups que busquen longevidad, a partir del entendimiento de su ciclo de vida y de posibles estrategias pertinentes a cada fase identificada.Objetivo do estudo: Esta pesquisa busca identificar quais estágios do modelo de ciclo de vida organizacional (CVO) de Lester, Parnell e Carraher (2003) são pertinentes às startups brasileiras e tem como objetivo: (i) identificar os estágios do CVO existentes em startups e (ii) apresentar recomendações estratégicas para cada estágio. Metodologia/abordagem: Trata-se de uma pesquisa com abordagem descritiva, não paramétrica, sendo utilizada a escala do tipo likert de questionário já validado em pesquisas anteriores, acrescido de perguntas sociodemográficas. Obteve-se 118 respostas válidas. Os dados foram analisados conforme o método de análise proposto por Frezatti et al. (2010), que preconiza que as questões inclusas no questionário possuem relação com os estágios do ciclo de vida do modelo de Lester, Parnell e Carraher (2003). Originalidade/Relevância: Diversos autores escreveram sobre o CVO, voltando suas pesquisas para pequenas ou grandes empresas e empresas familiares, porém não foi encontrado um modelo de CVO específico para startups, conforme pesquisa bibliográfica realizada como parte da investigação teórica deste estudo. Principais resultados: 118 respostas válidas foram obtidas. A análise dos resultados indica que nem todos os estágios existentes no modelo teórico de CVO existiam na amostra de startups investigada. Foram identificados os estágios de nascimento, crescimento e declínio e, a partir de tal constatação, foram feitas recomendações estratégias possíveis em cada um dos estágios. Contribuições teóricas/metodológicas: Os resultados obtidos com esta pesquisa podem ser aplicados por startups que busquem longevidade, a partir do entendimento do seu ciclo de vida e de possíveis estratégias pertinentes a cada fase identificada

CARREIRAS: NOVAS OU TRADICIONAIS? UM ESTUDO COM PROFISSIONAIS BRASILEIROS

Este artigo procurou identificar quais são as principais características apresentadas por alunos e ex-alunos de pós-graduação em relação às atitudes de carreira e  relacionar o perfil destes indivíduos às atitudes de três modelos de carreira. A metodologia utilizada foi quantitativa e o método de coleta de dados, o survey. Três resultados principais foram detectados. O primeiro é que não foi possível a distinção estatística entre as atitudes de carreira proteana e sem fronteiras. O segundo foi que as atitudes referentes às novas carreiras predominaram na maior parte dos respondentes, embora constatadas diferenças associadas ao gênero e geração do mesmo

Evolution favors protein mutational robustness in sufficiently large populations

BACKGROUND: An important question is whether evolution favors properties such as mutational robustness or evolvability that do not directly benefit any individual, but can influence the course of future evolution. Functionally similar proteins can differ substantially in their robustness to mutations and capacity to evolve new functions, but it has remained unclear whether any of these differences might be due to evolutionary selection for these properties. RESULTS: Here we use laboratory experiments to demonstrate that evolution favors protein mutational robustness if the evolving population is sufficiently large. We neutrally evolve cytochrome P450 proteins under identical selection pressures and mutation rates in populations of different sizes, and show that proteins from the larger and thus more polymorphic population tend towards higher mutational robustness. Proteins from the larger population also evolve greater stability, a biophysical property that is known to enhance both mutational robustness and evolvability. The excess mutational robustness and stability is well described by existing mathematical theories, and can be quantitatively related to the way that the proteins occupy their neutral network. CONCLUSIONS: Our work is the first experimental demonstration of the general tendency of evolution to favor mutational robustness and protein stability in highly polymorphic populations. We suggest that this phenomenon may contribute to the mutational robustness and evolvability of viruses and bacteria that exist in large populations

Inferring Visuomotor Priors for Sensorimotor Learning

Sensorimotor learning has been shown to depend on both prior expectations and sensory evidence in a way that is consistent with Bayesian integration. Thus, prior beliefs play a key role during the learning process, especially when only ambiguous sensory information is available. Here we develop a novel technique to estimate the covariance structure of the prior over visuomotor transformations – the mapping between actual and visual location of the hand – during a learning task. Subjects performed reaching movements under multiple visuomotor transformations in which they received visual feedback of their hand position only at the end of the movement. After experiencing a particular transformation for one reach, subjects have insufficient information to determine the exact transformation, and so their second reach reflects a combination of their prior over visuomotor transformations and the sensory evidence from the first reach. We developed a Bayesian observer model in order to infer the covariance structure of the subjects' prior, which was found to give high probability to parameter settings consistent with visuomotor rotations. Therefore, although the set of visuomotor transformations experienced had little structure, the subjects had a strong tendency to interpret ambiguous sensory evidence as arising from rotation-like transformations. We then exposed the same subjects to a highly-structured set of visuomotor transformations, designed to be very different from the set of visuomotor rotations. During this exposure the prior was found to have changed significantly to have a covariance structure that no longer favored rotation-like transformations. In summary, we have developed a technique which can estimate the full covariance structure of a prior in a sensorimotor task and have shown that the prior over visuomotor transformations favor a rotation-like structure. Moreover, through experience of a novel task structure, participants can appropriately alter the covariance structure of their prior

Expressions of Multiple Neuronal Dynamics during Sensorimotor Learning in the Motor Cortex of Behaving Monkeys

Previous studies support the notion that sensorimotor learning involves multiple processes. We investigated the neuronal basis of these processes by recording single-unit activity in motor cortex of non-human primates (Macaca fascicularis), during adaptation to force-field perturbations. Perturbed trials (reaching to one direction) were practiced along with unperturbed trials (to other directions). The number of perturbed trials relative to the unperturbed ones was either low or high, in two separate practice schedules. Unsurprisingly, practice under high-rate resulted in faster learning with more pronounced generalization, as compared to the low-rate practice. However, generalization and retention of behavioral and neuronal effects following practice in high-rate were less stable; namely, the faster learning was forgotten faster. We examined two subgroups of cells and showed that, during learning, the changes in firing-rate in one subgroup depended on the number of practiced trials, but not on time. In contrast, changes in the second subgroup depended on time and practice; the changes in firing-rate, following the same number of perturbed trials, were larger under high-rate than low-rate learning. After learning, the neuronal changes gradually decayed. In the first subgroup, the decay pace did not depend on the practice rate, whereas in the second subgroup, the decay pace was greater following high-rate practice. This group shows neuronal representation that mirrors the behavioral performance, evolving faster but also decaying faster at learning under high-rate, as compared to low-rate. The results suggest that the stability of a new learned skill and its neuronal representation are affected by the acquisition schedule.United States-Israel Binational Science FoundationIsrael Science FoundationIda Baruch FundRosetrees Trus

A Single-Rate Context-Dependent Learning Process Underlies Rapid Adaptation to Familiar Object Dynamics

Motor learning has been extensively studied using dynamic (force-field) perturbations. These induce movement errors that result in adaptive changes to the motor commands. Several state-space models have been developed to explain how trial-by-trial errors drive the progressive adaptation observed in such studies. These models have been applied to adaptation involving novel dynamics, which typically occurs over tens to hundreds of trials, and which appears to be mediated by a dual-rate adaptation process. In contrast, when manipulating objects with familiar dynamics, subjects adapt rapidly within a few trials. Here, we apply state-space models to familiar dynamics, asking whether adaptation is mediated by a single-rate or dual-rate process. Previously, we reported a task in which subjects rotate an object with known dynamics. By presenting the object at different visual orientations, adaptation was shown to be context-specific, with limited generalization to novel orientations. Here we show that a multiple-context state-space model, with a generalization function tuned to visual object orientation, can reproduce the time-course of adaptation and de-adaptation as well as the observed context-dependent behavior. In contrast to the dual-rate process associated with novel dynamics, we show that a single-rate process mediates adaptation to familiar object dynamics. The model predicts that during exposure to the object across multiple orientations, there will be a degree of independence for adaptation and de-adaptation within each context, and that the states associated with all contexts will slowly de-adapt during exposure in one particular context. We confirm these predictions in two new experiments. Results of the current study thus highlight similarities and differences in the processes engaged during exposure to novel versus familiar dynamics. In both cases, adaptation is mediated by multiple context-specific representations. In the case of familiar object dynamics, however, the representations can be engaged based on visual context, and are updated by a single-rate process

Lepton Flavor Non-Conservation

In the present work we review the most prominent lepton flavor violating processes (\mu \ra e\gamma, \mu \ra 3e, $(\mu , e)$ conversion, $M-\bar M$ oscillations etc), in the context of unified gauge theories. Many currently fashionable extensions of the standard model are considered, such as: {\it i)} extensions of the fermion sector (right-handed neutrino); {\it ii)} minimal extensions involving additional Higgs scalars (more than one isodoublets, singly and doubly charged isosinglets, isotriplets with doubly charged members etc.); {\it iii)} supersymmetric or superstring inspired unified models emphasizing the implications of the renormalization group equations in the leptonic sector. Special attention is given to the experimentaly most interesting $(\mu - e)$ conversion in the presence of nuclei. The relevant nuclear aspects of the amplitudes are discussed in a number of fashionable nuclear models. The main features of the relevant experiments are also discussed, and detailed predictions of the above models are compared to the present experimental limits.Comment: (IOA-300/93, review article, 83p, 6 epsf figures , available upon request from [email protected])

Effect of smoke on subcanopy shaded light, canopy temperature, and carbon dioxide uptake in an Amazon rainforest

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95278/1/gbc1694.pd

Phenology of Scramble Polygyny in a Wild Population of Chrysolemid Beetles: The Opportunity for and the Strength of Sexual Selection

Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations