628 research outputs found

    Underreaction to open market share repurchases

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    This article aims to investigate the long-term performance of a portfolio of firms that announced the repurchase of their own stocks in the Brazilian market from 2003 to 2014. Open market stock repurchase is a means to distribute cashflow to shareholders. Some of the reasons for a firm to buy back its own stocks are: to adjust its capital structure; to reduce excessive cash levels; as an alternative to dividends; and signaling to the market in order to reduce information asymmetry between the firm and its investors. If the signaling hypothesis is true, then forming a portfolio with shares that announce repurchases generates abnormal returns in the long run. Our results show that repurchase announcements in the open market signal stock underpricing, and abnormal returns can be earned using this strategy. Results are inconsistent with the semi-strong form of the efficient markets hypothesis, which states that one cannot earn abnormal returns with publicly available information. We obtained abnormal returns using the capital asset pricing model (CAPM) and Fama and French three-factor model. Additionally, we divided the sample in growth and value firms. We found that the average abnormal return for firms that announce repurchase programs ranges from 5.4% to 7.9% for up to a 3-year period after the announcement. For value companies (more likely to repurchase stocks due to undervaluation), abnormal returns can reach up to 11.5% per year.Este trabalho tem como objetivo analisar o desempenho de longo prazo de uma estratégia de investimento subsequente aos anúncios de programas de recompra de ações ocorridos no mercado brasileiro entre 2003 e 2014. Recomprar ações de emissão da própria empresa é um dos mecanismos utilizados para distribuir caixa aos acionistas. Dentre os motivos que podem explicar o interesse de uma empresa em readquirir suas próprias ações estão ajustar sua estrutura de capital, reduzir o excesso de caixa, como forma alternativa ao pagamento de dividendo ou como sinalização ao mercado, a fim de reduzir a assimetria de informação entre empresa e investidores. Sendo a hipótese de sinalização de desvalorização verdadeira, investir nas ações de empresas que fazem anúncios de recompra gera retornos anormais de longo prazo. A pesquisa fornece evidências de que os anúncios de programas de recompra de ações no mercado aberto sinalizam que o preço da ação da empresa anunciante está subavaliado, sendo possível obter retornos anormais com essa estratégia de investimento. Ao mesmo tempo, os resultados são inconsistentes com a hipótese de eficiência de mercado na forma semiforte, que diz que não é possível obter retornos anormais a partir de informação publicamente disponível. Os retornos anormais foram estimados por capital asset pricing model (CAPM) e pelo modelo de três fatores de Fama e French. Adicionalmente, estimamos os resultados subdividindo a amostra entre empresas de valor e de crescimento. Carteiras formadas por empresas que anunciaram programas de recompra apresentaram retornos anormais anuais de 5,4 a 7,9% para um horizonte de investimento de até três anos após o anúncio. Os retornos anormais das empresas de valor (mais suscetíveis a recomprar ações devido à subavaliação) são de até 11,5% ao ano

    A Low-Cost Energy-Efficient Raspberry Pi Cluster for Data Mining Algorithms

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    International audienceData mining algorithms are essential tools to extract information from the increasing number of large datasets, also called BigData. However, these algorithms demand huge amounts of computing power to achieve reliable results. Although conventional High Performance Computing (HPC) platforms can deliver such performance, they are commonly expensive and power-hungry. This paper presents a study of an unconventional low-cost energy-efficient HPC cluster composed of Raspberry Pi nodes. The performance, power and energy efficiency obtained from this unconventional platform is compared with a well-known coprocessor used in HPC (Intel Xeon Phi) for two data mining algorithms: Apriori and K-Means. The experimental results showed that the Raspberry Pi cluster can consume up to 88.35% and 85.17% less power than Intel Xeon Phi when running Apriori and K-Means, respectively, and up to 45.51% less energy when running Apriori

    Mechanical pruning and soil organic amendments in vineyards of Syrah: effects on grape composition

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    Aim: The interaction of mechanized pruning systems and soil organic amendment can increase vine productivity. However, since the increase in p roductivity may affect grape composition, this study aimed to understand the effects of the interaction between these two practices. Methods and materials: Two field trials were implemented in Shiraz vineyards in two different wine regions. Mechanical hedge pruning was compared with hand spur pruning and four different organic amendments were tested: biochar, municipal solid waste compost, cattle manure and sewage sludge. Results: Mechanical pruning reduced the total soluble solids (TSS) and pH of the grapes, but had no effects on the other variables. Organic amendments also reduced TSS, especially sewage sludge, and tended to reduce total anthocyanins and total phenols. The effect of the interaction between both factors on grape composition was never significant. A negative relationship between yield and TSS was observed, while titratable acidity had no relationship with yield. Total anthocyanins were also negatively related to yield. A positive relation between TSS and total anthocyanins was also observed. Conclusions: The results show that the combination of mechanical pruning and soil organic amendment is a powerful tool for increasing productivity, but it has some effects on grape composition. Significance and impact of study: The reduction in some fruit composition variables showed that, while mechanical pruning does not significantly affect grape composition, the choice of type and amount of organic amendment will depend on the destination of the grapesinfo:eu-repo/semantics/publishedVersio

    Skin picking treatment with the Rothbaum cognitive behavioral therapy protocol : a randomized clinical trial

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    Introduction: Although behavioral therapies can effectively treat skin picking disorder (SPD), there is no standardized treatment for improving SPD and its comorbidities and there is no group intervention option. This trial aimed to adapt the Rothbaum trichotillomania protocol to SPD (Study 1) and test its efficacy for treating SPD and comorbidities in individual and group formats (Study 2). Methods: The adapted protocol was applied to 16 SPD patients, who were allocated to group or individual treatment (Study 1). Afterwards, 54 patients were randomly allocated to treatment in an individual (n=27) or group format (n=27) (Study 2). In both studies, assessments of SPD severity, anxiety, depression, clinical status and skin lesion severity were performed at baseline and the endpoint. Results: The adapted protocol was feasible in both treatment modalities (Study 1) and led to high SPD remission rates (individual 63%; group 52%), with no significant difference between intervention types (p = 0.4) (Study 2). SPD, anxiety, and depression symptoms and objective patient lesion measures improved after treatment. There was large effect size for SPD symptom improvement in both treatment types (Cohen’s d: group = 0.88; individual = 1.15) (Study 2). Conclusion: The adapted Rothbaum protocol was effective for SPD remission, comorbidities, and skin lesions, both in individual and group formats

    Endogeneity in panel data regressions: methodological guidance for corporate finance researchers

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    Purpose –To describe the use of specific lags (and/or temporal differences) of the original regressors as instrumental variables in a succinct and practical way, showing, by means of a theoretical discussion illustrated by an original simulation exercise, how combining these with adequate modeling of firm and time fixed effects can address not only the dynamic endogeneity problem, but also those derived from the presence of omitted variables, measurement errors, and simultaneity between dependent and independent variables. Design/methodology/approach – Monte Carlo simulation Findings – The traditional OLS, RE, and FE estimators may be inconsistent in the presence of endogeneity problems that are quite plausible in the context of corporate finance. On the other hand, the estimation methods for panel data based on GMM that use assumptions of sequential exogeneity of the regressors present alternatives that are capable of effectively overcoming all the problems listed (provided these assumptions are valid) even if the researcher does not have good instrumental variables that are external to the model Originality/value –The paper discusses and illustrates a greater number of endogeneity problems, showing how they are addressed by different estimators for panel data, using less technical and more accessible language for researchers not yet initiated in the intricacies of estimating dynamic models for panel data

    Germline MUTYH (MYH) mutations in portuguese individuals with multiple colorectal adenomas

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    Germinal mutations in the base excision repair (BER) gene MUTYH (MYH) have recently been described in association with predisposition to multiple colorectal adenomas and cancer. In contrast to the classic dominant condition of familial adenomatous polyposis (FAP) due to germinal mutations in the APC gene, the MYH polyposis is an autosomal recessive disease. The identification of individuals affected by MYH polyposis brings new and important implications for the diagnostic, screening, genetic counseling, follow up and therapeutic options in these patients. In this study, screening for germinal mutations in the MYH gene was performed in 53 Portuguese individuals with multiple colorectal adenomas or classic adenomatous polyposis, in whom no mutation had been identified in the APC gene. The results revealed the presence of biallelic germline MYH mutations in 21 patients. In addition, we here report 3 mutations (c.340T>C [p.Y114H]; c.503G>A [p.R168H]; and c.1186_1187insGG [p.E396fsX437]) which, to our knowledge, have not been previously described. © 2004 Wiley-Liss, Incinfo:eu-repo/semantics/publishedVersio

    Well-being at work, productivity, and coping with stress during the COVID-19 pandemic

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    This study aims to analyze the mechanisms through which the coronavirus disease (COVID-19) pandemic impacts on well-being at work and on productivity. The secondary objective is to identify stress management strategies for the work environment during the pandemic. This is an integrative review. Phase 1 consisted of searches of open access electronic databases (MEDLINE, SciELO, Bireme, and LILACS) for papers published in 2020 addressing mental health, work, and pandemics. Phase 2 consisted of selecting literature recommended by specialists in occupational psychiatry and positive psychology. These materials were read and critically analyzed. Forty references were included in the literature review. The articles reviewed were classified into the following categories: articles concerning work relationships in Brazil; articles describing the impact of pandemics on mental health and work; articles focusing on the work of health professionals during pandemics; articles about well-being at work; and papers proposing strategies to improve well-being and productivity and to promote mental health. The COVID-19 pandemic can have a significant impact on workers’ mental health and productivity. Most professionals face a need to adapt to changes, which can decrease their feeling of well-being. Consequently, strategies to promote well-being and mental health in the work environment should be a priority. Work routines were modified after the COVID-19 pandemic set in and assessing these changes is essential to maintain workers’ mental health. By so doing, it is possible to promote general well-being and post-traumatic recovery and reduce stress levels

    Broadcast spawning coral <i>Mussismilia hispida</i> can vertically transfer its associated bacterial core

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    The hologenome theory of evolution (HTE), which is under fierce debate, presupposes that parts of the microbiome are transmitted from one generation to the next [vertical transmission (VT)], which may also influence the evolution of the holobiont. Even though bacteria have previously been described in early life stages of corals, these early life stages (larvae) could have been inoculated in the water and not inside the parental colony (through gametes) carrying the parental microbiome. How Symbiodinium is transmitted to offspring is also not clear, as only one study has described this mechanism in spawners. All other studies refer to incubators. To explore the VT hypothesis and the key components being transferred, colonies of the broadcast spawner species Mussismilia hispida were kept in nurseries until spawning. Gamete bundles, larvae and adult corals were analyzed to identify their associated microbiota with respect to composition and location. Symbiodinium and bacteria were detected by sequencing in gametes and coral planula larvae. However, no cells were detected using microscopy at the gamete stage, which could be related to the absence of those cells inside the oocytes/dispersed in the mucus or to a low resolution of our approach. A preliminary survey of Symbiodinium diversity indicated that parental colonies harbored Symbiodinium clades B, C and G, whereas only clade B was found in oocytes and planula larvae [5 days after fertilization (a.f.)]. The core bacterial populations found in the bundles, planula larvae and parental colonies were identified as members of the genera Burkholderia, Pseudomonas, Acinetobacter, Ralstonia, Inquilinus and Bacillus, suggesting that these populations could be vertically transferred through the mucus. The collective data suggest that spawner corals, such as M. hispida, can transmit Symbiodinium cells and the bacterial core to their offspring by a coral gamete (and that this gamete, with its bacterial load, is released into the water), supporting the HTE. However, more data are required to indicate the stability of the transmitted populations to indicate whether the holobiont can be considered a unit of natural selection or a symbiotic assemblage of independently evolving organisms

    Mechanical pruning and soil organic amending in two terroirs. Effects on wine chemical composition and sensory profile

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    The knowledge about the interaction between mechanical pruning and soil organic amending is still scarce. This study aimed to examine the effects of the interaction between these two practices on wine quality. Syrah grapes from two trial fields in Portugal subjected to two different pruning systems (mechanical pruning; hand spur pruning) and five different organic amendment treatments (control, biochar, municipal solid waste compost, cattle manure, and sewage sludge) were harvested and vinified for four years. Mechanical pruning significantly reduced wine alcoholic strength, pH, and total anthocyanins. Mechanical pruning and organic amendments, tendentially reduced wine total phenols and tannin power, known as an “estimation of the astringency potential of the wines”. Tasters found low but significant differences in global appreciation with the pruning system. Sludge tended to reduce wine global appreciation more than municipal solid waste compost and cattle manure, while biochar had no effect on tasters’ preference when compared to the control. There was strong relation between yield and tasters’ preference only above 6 kg/vine and 8 kg/vine depending on the terroir. Mechanical pruning tendentially has significant effects on wine quality when yield raises above a certain level. Thus, with this pruning system, the choice of the organic amendment and its amount must be done considering the destiny of the produced grapes. To the best of our knowledge, effects of the interaction of mechanical pruning with soil organic amending on wine quality are a noveltyinfo:eu-repo/semantics/publishedVersio

    Ação de estimulantes e reguladores vegetais no crescimento de girassol

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    This experiment was carried out to determine the effects of Cytozyme (1 ml.1-1), Ergostim (2 ml.1-1), Figaron (1 ml.1-1) and Multiprop (1 ml.1-1) on growth of Helianthus annuus cv. Anhandy, under laboratory conditions. Measurements realized 7 days after application of growth substances in sunflower plants with 21 days of age, cultivated on pots, showed that Ergostim promoted higher growth of sunflower hypocotyl, Multipropand Figaron increased development of sunflower hypocotyl in relation to check.Com o objetivo de estudar os efeitos de estimulantes e reguladores vegetais, sob condições de laboratório, no desenvolvimento da radícula e do hipocótilo de Helianthus annuus cv. Anhandy, plantas com 21 dias de idade, cultivadas em vaso, foram pulverizadas com Cytozyme 1 ml. 1-1, Ergostim 2 ml.1-1, Figaron 1 ml.1-1 e Multiprop 1 ml.1-1, além do controle. Sete dias depois verificou-se que Ergostim promoveu a maior variação no crescimento do hipocótilo, sendo que Multiprop e Figaron também incrementaram o desenvolvimento. Cytozyme causou significativo aumento no comprimento do hipocótilo do girassol com relação ao controle
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