886 resultados para Difference-in-Difference
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This Article does not have an abstract.
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Acute physical exercise is associated with increased oxygen consumption, which could result in an increased formation of reactive oxygen species (ROS). ROS can react with several organic structures, namely DNA, causing strand breaks and a variety of modified bases in DNA. Physical exercise training seems to decrease the incidence of oxidative stress-associated diseases, and is considered as a key component of a healthy lifestyle. This is a result of exercise-induced adaptation, which has been associated with the possible increase in antioxidant activity and in oxidative damage repair enzymes, leading to an improved physiological function and enhanced resistance to oxidative stress (Radak et al. 2008). Human 8-oxoguanine DNA glycosylase 1 (hOGG1) is involved in the base excision repair (BER) pathway and encodes an enzyme responsible for removing the most common product of oxidative damage in DNA, 8-hydroxyguanine (8-OH-G). The genetic polymorphism of hOGG1 at codon 326 results in a serine (Ser) to cysteine (Cys) amino acid substitution (Ser326Cys). It has been suggested that the carriers of at least one hOGG1Cys variant allele exhibit lower 8-OH-G excision activity than the wild-type (Wilson et al. 2011). The aim of this study was to investigate the possible influence of hOGG1 Ser326Cys polymorphism on DNA damage and repair activity in response to 16 weeks of combined physical exercise training, in thirty healthy Caucasian men. Comet assay was carried out using peripheral blood lymphocytes and enabled the evaluation of DNA damage, both strand breaks and FPG-sensitive sites, and DNA repair activity. Genotypes were determined by PCR-RFLP analysis. The subjects with Ser/Ser genotype were considered as wild-type group (n=20), Ser/Cys and Cys/Cys genotype were analyzed together as mutant group (n=10). Regarding differences between pre and post-training in the wild-type group, the results showed a significant decrease in DNA strand breaks (DNA SBs) (p=0.002) and also in FPG-sensitive sites (p=0.017). No significant differences were observed in weight (p=0.389) and in lipid peroxidation (MDA) (p=0.102). A significant increase in total antioxidant capacity (evaluated by ABTS) was observed (p=0.010). Regarding mutant group, the results showed a significant decrease in DNA SBs (p=0.008) and in weight (p=0.028). No significant differences were observed in FPG-sensitive sites (p=0.916), in ABTS (p=0.074) and in MDA (p=0.086). No significant changes in DNA repair activity were observed in both genotype groups. This preliminary study suggests the possibility of different responses in DNA damage to physical exercise training, considering the hOGG1 Ser326Cys polymorphism.
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The knowledge-based society we live in has stressed the importance of human capital and brought talent to the top of most wanted skills, especially to companies who want to succeed in turbulent environments worldwide. In fact, streams, sequences of decisions and resource commitments characterize the day-to-day of multinational companies (MNCs). Such decision-making activities encompass major strategic moves like internationalization and new market entries or diversification and acquisitions. In most companies, these strategic decisions are extensively discussed and debated and are generally framed, formulated, and articulated in specialized language often developed by the best minds in the company. Yet the language used in such deliberations, in detailing and enacting the implementation strategy is usually taken for granted and receives little if any explicit attention (Brannen & Doz, 2012) an can still be a “forgotten factor” (Marschan et al. 1997). Literature on language management and international business refers to lack of awareness of business managers of the impact that language can have not only in communication effectiveness but especially in knowledge transfer and knowledge management in business environments. In the context of MNCs, management is, for many different reasons, more complex and demanding than that of a national company, mainly because of diversity factors inherent to internationalization, namely geographical and cultural spaces, i.e, varied mindsets. Moreover, the way of functioning, and managing language, of the MNC depends on its vision, its values and its internationalization model, i.e on in the way the MNE adapts to and controls the new markets, which can vary essentially from a more ethnocentric to a more pluricentric focus. Regardless of the internationalization model followed by the MNC, communication between different business units is essential to achieve unity in diversity and business sustainability. For the business flow and prosperity, inter-subsidiary, intra-company and company-client (customers, suppliers, governments, municipalities, etc..) communication must work in various directions and levels of the organization. If not well managed, this diversity can be a barrier to global coordination and create turbulent environments, even if a good technological support is available (Feely et al., 2002: 4). According to Marchan-Piekkari (1999) the tongue can be both (i) a barrier, (ii) a facilitator and (iii) a source of power. Moreover, the lack of preparation for the barriers of linguistic diversity can lead to various costs, including negotiations’ failure and failure on internationalization.. On the other hand, communication and language fluency is not just a message transfer procedure, but above all a knowledge transfer process, which requires extra-linguistic skills (persuasion, assertiveness …) in order to promote credibility of both parties. For this reason, MNCs need a common code to communicate and trade information inside and outside the company, which will require one or more strategies, in order to overcome possible barriers and organization distortions.
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Every month we see to be published dozens of scientific papers about etiology and physiopathology of CP, imaging, treatment, survival, quality of life of patients and of mothers (just a few) and so on. Papers dealing with the feelings and the problems of siblings of children and adults with CP in the most important scientific journals are extremely rare. However in internet we can find the sites of the most important Cerebral Palsy Societies, like the British, the Australian and the American ones already devoting a special attention to the issue of siblings; we also can see several interesting blogs of parents sharing their experiences not only with the handicapped child but also with the siblings, even counseling some books written for children giving practical advices how to deal and live with a handicapped sibling. What was a surprise to me were the several sites of adults having a disabled sibling, frequently with CP, in a new situation: without parents to care them.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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In this paper, we investigate whether being part of the euro area influences the conditional probability of going through a sudden stop or a bonanza of capital flows. Our sample period is from 1995 until 2014. We identify these two phenomena and we evaluate which push and pull factors help predict the conditional probability of experiencing one of them. We find that most countries had significant capital inflows until 2008 and that there were more sudden stops during the recent financial crisis than in any other moment in our sample. The factors that better help forecast the conditional probability of a sudden stop are global uncertainty (represented by the push factor “Volatility Index”), and the domestic economic activity (pull factors “GDP growth” and “consumer confidence”). An indicator of country risk (pull factor “change in credit rating”) is the most significant one for predicting bonanzas. Ultimately, we find no evidence that being part of the euro area influences the conditional probability of going through a sudden stop or a bonanza.
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The difference between the statutory and effective tax rate for listed groups is a complex variable influenced by a variety of factors. This paper aims to analyze whether this difference exists for listed groups in the German market and tests which factors have an impact on it. Thus the sample consists of 130 corporations listed in the three major German stock indices. The findings suggest that the companies that pay less than the statutory rate clearly outweigh the ones that pay more, and that the income earned from associated companies has a significant impact on this difference.
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Breastfeeding is the natural and safe way of feeding small infants, providing nutritional, immunological, psychological and economic recognized and unquestionable advantages. These qualities are especially important in premature infants, because of their vulnerability. Despite highly desirable, there is, in general, little success in breastfeeding preterm infants, especially in special care neonatal units. There are evidences that a high supportive hospital environment, with an interdisciplinary team, makes possible to these infants to be breastfed. In this article, the authors present an up-to-date review about the components of human milk and its unique characteristics, as well as describes aspects that make the breast milk particularly suitable for feeding the premature newborn.
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PURPOSE: To assess differences in the in-hospital mortality (HM) rate between men and women with unstable angina pectoris (UA) according to age, depression of the ST segment, history of previous acute myocardial infarction (AMI), and risk factors for coronary heart disease. METHODS: From October 96 to March 98, 261 patients with UA were selected. Logistic regression models were developed to adjust the association between sex and HM for possible influence of covariables, such as hypertension, diabetes mellitus, dyslipidemia, sedentary lifestyle, smoking, and familial history of early coronary heart disease. RESULTS: HM due to UA was approximately three times higher in women (9.3%; 12/129) than in men (3.0%; 4/132) accounting for a relative risk of 3.07; 95% confidence interval (CI) =1.02-9.27. In logistic regression models, the association between sex and death was not significantly altered when the following parameters were considered: age, depression of the ST segment, history of previous AMI and risk factors for coronary heart disease. The nonadjusted and adjusted odds ratio (OR) for the distinct covariables were 3.28 (CI 95%=1.03-10.45) and 3.14 (CI = 95% = 0.88-11.20), respectively. CONCLUSION: Similarly to AMI, HM in UA is higher in women than in men. Age, risk factors for coronary heart disease, and depression of the ST segment in the electrocardiogram on patients' admission to the hospital did not significantly influence the association between sex and death.
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We construct estimates of educational attainment for a sample of OECD countries using previously unexploited sources. We follow a heuristic approach to obtain plausible time profiles for attainment levels by removing sharp breaks in the data that seem to reflect changes in classification criteria. We then construct indicators of the information content of our series and a number of previously available data sets and examine their performance in several growth specifications. We find a clear positive correlation between data quality and the size and significance of human capital coefficients in growth regressions. Using an extension of the classical errors in variables model, we construct a set of meta-estimates of the coefficient of years of schooling in an aggregate Cobb-Douglas production function. Our results suggest that, after correcting for measurement error bias, the value of this parameter is well above 0.50.
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Elevated high-sensitivity C-reactive protein (hs-CRP) concentration is associated with an increased risk of cardiovascular disease but this association seems to be largely mediated via conventional cardiovascular risk factors. In particular, the association between hs-CRP and obesity has been extensively demonstrated and correlations are stronger in women than men. We used fractional polynomials-a method that allows flexible modeling of non linear relations-to investigate the dose/response mathematical relationship between hs-CRP and several indicators of adiposity in Caucasians (Switzerland) and Africans (Seychelles) surveyed in two population-based studies. This relationship was non-linear exhibiting a steeper slope for low levels of hs-CRP and a higher level in women. The observed sex difference in the relationship between hs-CRP and adiposity almost disappeared upon adjustment for leptin, suggesting that these sex differences might be partially mediated, by leptin. All these relationship were similar in Caucasians and Africans. This is the first report on a non-linear relation, stratified by gender, between hs-CRP and adiposity.
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We use a panel of over 120,000 Chinese firms of different ownership types over the period 2000-2007 to analyze the linkages between investment in fixed and working capital and financing constraints. We find that those firms characterized by high working capital display high sensitivities of investment in working capital to cash flow (WKS) and low sensitivities of investment in fixed capital to cash flow (FKS). We then construct and analyze firm-level FKS and WKS measures and find that, despite severe external financing constraints, those firms with low FKS and high WKS exhibit the highest fixed investment rates. This suggests that good working capital management may help firms to alleviate the effects of financing constraints on fixed investment.
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The effects of structural breaks in dynamic panels are more complicated than in time series models as the bias can be either negative or positive. This paper focuses on the effects of mean shifts in otherwise stationary processes within an instrumental variable panel estimation framework. We show the sources of the bias and a Monte Carlo analysis calibrated on United States bank lending data demonstrates the size of the bias for a range of auto-regressive parameters. We also propose additional moment conditions that can be used to reduce the biases caused by shifts in the mean of the data.
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Rapport de synthèse : Cette recherche s'intéresse (1) au port et à l'utilisation d'armes chez les adolescents ainsi que (2) aux rôles des facteurs environnementaux et individuels dans la violence juvénile. Les données étaient tirés de SMASH 2002 (Swiss multicenter adolescent survey on health 2002), étude dans laquelle un échantillon représentatif de 7548 étudiants et apprentis âgés entre 16 et 20 ans vivant en Suisse ont été interrogés Dans une première étude, les adolescents ayant porté une arme (couteau, masse, coup de poing américain, pistolet/autre arme à feu, spray) durant l'année précédant l'enquête étaient comparés avec ceux n'ayant pas porté d'arme. Ensuite, dans le sous-échantillon de porteurs d'armes, ceux ayant uniquement porté l'arme étaient comparés avec ceux ayant utilisé une arme dans une bagarre. Des facteurs individuels, familiaux, scolaires et sociaux ont été étudiés à l'aide d'analyses bivariées et multivariées. 13.7% des jeunes vivant en Suisse ont porté une arme dans l'année précédant l'enquête. 6.2% des filles porteuses d'armes et 19.9% des garçons porteurs d'armes ont fait usage de l'arme dans une bagarre. Chez les garçons et chez les filles, les porteurs d'armes étaient plus souvent délinquants et victimes de violence physique. Les garçons porteurs d'armes étaient plus souvent des apprentis, à la recherche de sensations fortes, porteurs de tatouages, avaient une mauvaise relation avec leurs parents, étaient dans des bagarres sous l'influence de substances, et avaient des relations sexuelles à risque. En comparaison avec les porteuses d'armes, les filles utilisatrices d'armes étaient plus souvent fumeuses quotidiennes. Les garçons ayant utilisé leur arme étaient plus souvent nés à l'étranger, vivaient dans un milieu urbain, étaient des apprentis, avaient un mauvais contexte scolaire, avaient des relations sexuelles à risque et étaient impliqués dans des bagarres sous l'influence de substances. Nos résultats montrent que porter une arme est un comportement relativement fréquent chez les adolescents vivant en Suisse et qu'une proportion non négligeable de ces porteurs d'armes ont utilisé l'arme dans une bagarre. De ce fait, une discussion sur le port d'arme devrait être incluse dans l'entretien clinique ainsi que dans les programmes de prévention visant les adolescents. Dans une deuxième étude, la violence juvénile était définie comme présente si l'adolescent avait commis au moins un des quatre délits suivants durant l'année précédant l'enquête: attaquer un adulte, arracher ou voler quelque chose, porter une arme ou utiliser une arme dans une bagarre. Des niveaux écologiques étaient testés et résultaient en un modèle à trois niveaux pour les garçons (niveau individuel, niveau classe et niveau école) et, à cause d'une faible prévalence de la violence chez les filles, en un modèle à un niveau (individuel) pour les filles. Des variables dépendantes étaient attribuées à chaque niveau, en se basant sur la littérature. Le modèle multiniveaux des garçons montrait que le niveau école (10%) et le niveau classe (24%) comptaient pour plus d'un tiers de la variance inter-individuelle dans le comportement violent. Les facteurs associés à ce comportement chez les filles étaient être victime de violence physique et la recherche de sensations fortes. Pour les garçons, les facteurs explicatifs de la violence étaient pratiquer des relations sexuelles à risque, être à la recherche de sensations fortes, être victime de violence physique, avoir une mauvaise relation avec les parents, être déprimé et vivre dans une famille monoparentale au niveau individuel, la violence et les actes antisociaux au niveau de la classe et être apprenti au niveau de l'école. Des interventions au niveau de la classe ainsi qu'un règlement explicit en ce qui concerne la violence et d'autres comportements à risque dans des écoles devraient être prioritaires pour la prévention de la violence chez les adolescents. En outre, la prévention devrait tenir compte des différences entre les sexes.