74 resultados para Fama-MacBeth regressions


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This study utilised the preload paradigm to evaluate whether dietary restraint, impulsivity, or their interaction significantly predicts heightened food consumption among male and/or female participants. Following a high calorie preload, 79 participants aged 18 to 40 (53 females and 26 males) completed a deceptive taste test and questionnaires measuring restraint and impulsivity levels. A series of hierarchical regressions were run, controlling for self-rated hunger levels. A significant negative association between level of restraint and food consumption post-preload was found for males, but this relationship was not significant for female participants. The hypothesis that impulsivity would directly predict heightened food consumption was not supported for either gender. However, impulsivity was found to significantly moderate the relationship between restraint and food intake in the male sample, but not the female, providing partial support for this hypothesis. Potential reasons for this gender-specific interaction effect of impulsivity and restraint for food consumption are discussed. More broadly, present findings highlight the need for further consideration of the role of impulsivity in undermining food intake of restrained eaters. Future research should also consider how preload effects may differ across gender.

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Gastrointestinal nematodes limit the growth, production and welfare of goats but there are few reliable sources of information for recommending management practices across flocks. The effects of animal species (Angora goat, Merino sheep, mixed-grazed goats and mixed-grazed sheep at the ratio of 1:1) and stocking rate (SR: 7.5, 10, 12.5 animals/ha) on gastrointestinal parasitism were determined in a replicated experiment on improved annual temperate pastures in southern Australia, from 1981 to 1984. Detailed monitoring of gastrointestinal nematodes was undertaken on animals before, during (five times per year) and at the conclusion of studies using faecal strongyle egg counts (WEC) and total worm counts. Sheep had a greater proportion of nematodes as Teladorsagia spp. and goats a greater incidence of Trichostrongylus spp. Both goats and sheep developed resistance to Nematodirus spp. during the experiment. WEC was similar in goats and sheep at the start of the experimental period but, thereafter, was consistently greater in goats than in sheep. While WEC was highly related to total worm count, the regressions for sheep and goats were different. Increasing the SR increased the WEC of goats and mixed-grazed goats but not of sheep. During the experiment, WEC declined at 7 and 10 animals/ha but increased at 12.5/ha. Mixed grazing with goats provided beneficial effects for sheep at all stocking rates, but the effects for goats were dependent on the stocking rate, being beneficial at 7.5 and 10/ha but harmful at 12.5/ha. The WEC of separately grazed goats were generally higher than the WEC of mixed grazed goats. The WEC of mixed sheep were lower than those of separately grazed sheep. During the experiment, the WEC of mixed grazed sheep declined faster than the WEC of separately grazed sheep but the WEC of separately grazed goats at 12.5/ha and of mixed grazed goats at 10 and 12.5/ha increased. Under the environmental and pastoral conditions examined, Angora wether goats should not be grazed at SR above those recommended for wether sheep. In the present study, the impact of gastrointestinal-nematode infections in goats was reduced at lower SR. Further, mixed grazing of Angora wether goats with wether sheep at or below the recommended SR resulted in reduced gastrointestinal parasitism for both sheep and goats, compared with monospecific grazing conditions. Goats did not represent a gastrointestinal-nematode hazard to sheep. © 2014 CSIRO.

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The management of a firm's green operations is increasingly important for marketing strategists. The purpose of this study is to investigate the cross-influences of green marketing strategy and the key internal green functional areas in a firm. We use the antecedents of marketing strategy and identify relationships between green marketing strategy and key supporting internal environmental operations of firms with respect to (1) green suppliers, (2) environmental resource management, (3) green research and development, and (4) environmental manufacturing processes and procedures. The statistical techniques of parallel analysis, factor analysis and multiple regressions are used to analyze data collected from 332 firms. The results identify that among the four functional areas of firms adopting green marketing strategy. Two are more likely to influence green marketing strategy – supplier selection and research and development. Implications are discussed. The findings contribute to the theory of green marketing strategy. Future research is recommended.

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Aim: The aim of the present study was to examine migration- and socioeconomic-related influences on obesity among African migrant adolescents in Melbourne, Australia. Methods: Anthropometric data were collected from 99 parents and 100 adolescent offspring who also completed questionnaires eliciting demographic, socioeconomic and migration data. Multiple linear regressions were used to assess the relationship between migration- and socioeconomic-related factors and adolescent body mass index (BMI). Results: Only gender and parental BMI were associated with adolescent BMI after adjusting for adolescent age, adolescent gender, religion, parental BMI, parental education level and annual income. Boys (β=-1.45; P < 0.05) had lower BMI than girls. Parental and adolescent BMI were positively associated (β = 0.11; P < 0.05). In examining migration-related factors and adolescent BMI, after adjusting for gender and parental BMI, parental acculturation patterns and pre-migration life environment were associated with adolescent BMI, explaining, respectively, 6.5 and 4.0% of the variance in BMI. An integrated parental acculturation pattern was negatively associated with adolescent BMI (β=-0.17; P < 0.05) while adolescents whose parents came from rural areas had a higher BMI (β = 1.48; P < 0.05) than those whose parents came from urban areas. Adolescent acculturation patterns and length of stay in Australia were non-significantly associated with their BMI. Conclusions: Gender, pre-migration life environment and parental acculturation patterns seem to influence the prevalence of overweight and obesity among African migrant adolescents. Culturally competent obesity prevention programmes targeted towards African adolescents should consider these aspects in their design and delivery; however, further research is required to determine their relative contributions to African adolescent obesity in Australia.

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Objectives: To (a) assess the statistical power of nursing research to detect small, medium, and large effect sizes; (b) estimate the experiment-wise Type I error rate in these studies; and (c) assess the extent to which (i) a priori power analyses, (ii) effect sizes (and interpretations thereof), and (iii) confidence intervals were reported. Design: Statistical review. Data sources: Papers published in the 2011 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. Review methods: Papers were assessed for statistical power, control of experiment-wise Type I error, reporting of a priori power analyses, reporting and interpretation of effect sizes, and reporting of confidence intervals. The analyses were based on 333 papers, from which 10,337 inferential statistics were identified. Results: The median power to detect small, medium, and large effect sizes was .40 (interquartile range [. IQR]. = .24-.71), .98 (IQR= .85-1.00), and 1.00 (IQR= 1.00-1.00), respectively. The median experiment-wise Type I error rate was .54 (IQR= .26-.80). A priori power analyses were reported in 28% of papers. Effect sizes were routinely reported for Spearman's rank correlations (100% of papers in which this test was used), Poisson regressions (100%), odds ratios (100%), Kendall's tau correlations (100%), Pearson's correlations (99%), logistic regressions (98%), structural equation modelling/confirmatory factor analyses/path analyses (97%), and linear regressions (83%), but were reported less often for two-proportion z tests (50%), analyses of variance/analyses of covariance/multivariate analyses of variance (18%), t tests (8%), Wilcoxon's tests (8%), Chi-squared tests (8%), and Fisher's exact tests (7%), and not reported for sign tests, Friedman's tests, McNemar's tests, multi-level models, and Kruskal-Wallis tests. Effect sizes were infrequently interpreted. Confidence intervals were reported in 28% of papers. Conclusion: The use, reporting, and interpretation of inferential statistics in nursing research need substantial improvement. Most importantly, researchers should abandon the misleading practice of interpreting the results from inferential tests based solely on whether they are statistically significant (or not) and, instead, focus on reporting and interpreting effect sizes, confidence intervals, and significance levels. Nursing researchers also need to conduct and report a priori power analyses, and to address the issue of Type I experiment-wise error inflation in their studies. © 2013 .

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BACKGROUND: Controlling feeding practices are linked to children's self-regulatory eating practices and weight status. Maternal reports of controlling feeding practices are not always significantly related to independently rated mealtime observations. However, prior studies only assessed 1 mealtime observation, which may not be representative of typical mealtime settings or routines. OBJECTIVES: The first aim was to examine associations between reported and observed maternal pressure to eat and restriction feeding practices at baseline (T1) and after ∼12 mo (T2). The second aim was to evaluate relations between maternal and child factors [e.g., concern about child weight, child temperament, child body mass index (BMI)-for-age z scores (BMIz)] at T1 and reported and observed maternal pressure to eat and restriction feeding practices (T1 and T2). The third aim was to assess prospective associations between maternal feeding practices (T1) and child eating behaviors (T2) and child BMIz (T2). METHODS: A sample of 79 mother-child dyads in Victoria, Australia, participated in 2 lunchtime home observations (T1 and T2). BMI measures were collected during the visits. Child temperament, child eating behaviors, maternal parenting styles, and maternal feeding practices were evaluated at T1 and T2 via questionnaires. Associations were assessed with Pearson's correlation coefficients, paired t tests, and hierarchical regressions. RESULTS: Reported restriction (T1) was inversely associated with observed restriction at T1 (r = -0.24, P < 0.05). Reported pressure to eat (T2) was associated with observed pressure to eat (T2) (r = 0.48, P < 0.01) but only for mothers of girls. Maternal weight concern was associated with reported restriction at T1 (r = 0.29, P < 0.01) and T2 (r = 0.36, P < 0.01), whereas observed restriction (T1) was prospectively associated child BMI at T2 (β = -0.18, P < 0.05). CONCLUSIONS: Maternal reports may not always reflect feeding practices performed during mealtimes; it is possible some mothers may not be aware of their practices or observations may not capture covert controlling strategies.

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Background Cabazitaxel, abiraterone, and enzalutamide are survival-prolonging treatments in men with castration-resistant prostate cancer (CRPC) progressing following docetaxel chemotherapy. The sequential activity of these agents has not been studied and treatment sequencing remains a key dilemma for clinicians. Objective To describe the antitumour activity of cabazitaxel after docetaxel and next-generation endocrine agents. Design, setting, and participants We report on a cohort of 59 men with progressing CRPC treated with cabazitaxel, 37 of whom had received prior abiraterone and 9 of whom had received prior enzalutamide. Outcome measurements and statistical analysis Changes in prostate-specific antigen (PSA) level were used to determine activity on abiraterone, enzalutamide, and cabazitaxel treatment. Radiologic tumour regressions according to Response Evaluation Criteria in Solid Tumors (RECIST) and symptomatic benefit were evaluated for cabazitaxel therapy. Results and limitations The post-endocrine-therapy patients received abiraterone (n = 32), sequential abiraterone and enzalutamide (n = 5) or enzalutamide (n = 4). These patients received a median of 7 mo of abiraterone and 11 mo of enzalutamide. A median of six cabazitaxel cycles (range: 1-10 cycles) were delivered, with ≥50% PSA declines in 16 of 41 (39%) patients, soft tissue radiologic responses in 3 of 22 (14%) evaluable patients, and symptomatic benefit in 9 of 37 evaluable patients (24%). Median overall survival and progression-free survival were 15.8 and 4.6 mo, respectively. Antitumor activity on cabazitaxel was less favourable in the abiraterone- and enzalutamide-naïve cohort (n = 18), likely reflecting biologic differences in this cohort. These data were obtained from a retrospective analysis. Conclusions This is the first report of cabazitaxel activity in CRPC progressing after treatment with docetaxel and abiraterone or enzalutamide. We demonstrate significant cabazitaxel activity in this setting. Patient summary We looked at the antitumour activity of the chemotherapy drug cabazitaxel in men previously treated with docetaxel chemotherapy and the hormonal drugs abiraterone and enzalutamide. Cabazitaxel appeared active when given after abiraterone and enzalutamide. We can reassure men that cabazitaxel can be used after these novel endocrine treatments. © 2013 European Association of Urology.

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Purpose-The purpose of this paper is to investigate the relationships between components of the psychological contract, organisational justice, and negative affectivity (NA), with key employee outcomes (i.e. organisational commitment, job satisfaction, depression, and psychological distress) among allied health professionals. Design/methodology/approach-In total, 134 (response rate of 46 per cent) Australian allied health professional completed a questionnaire. Findings-Multiple regressions revealed that higher NA was associated with lower organisational commitment, lower job satisfaction, and higher levels of depression. The psychological contract variable, breach, was associated with depression. Informational justice was associated with organisational commitment. Distributive justice was associated with job satisfaction. Research limitations/implications-This research is limited by its cross-sectional design and that the data were self-reported. The results obtained suggest the potential utility of collecting longitudinal data to replicate and extend the results. Practical implications-While NA may be beyond management control, it may be ameliorated by attention to improving communication of management decisions and by sensitivity to the elements implicit in psychological contracts. The negative consequences of contract breach may be offset by informational and distributive justice. Originality/value-This study is one of the first to examine multiple measures of the psychological contract in addition to organisational justice and NA. Further, this study adds to the literature for allied health professionals, where little is known about factors contributing to their turnover.

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Despite the widespread use of ground rules in forensic interview guidelines, it is unknown whether children retain and apply these rules throughout narrative interviews. We evaluated the capacity of 260 five- to nine-year-olds to utilize three ground rules. At the beginning of the interview all children heard the rules; half also practiced them. Children then responded to open-ended prompts about a repeated laboratory event and were assessed for their application of the rules. Logistic regressions revealed that practice only benefitted the use of the "don't know" rule. Although the children accurately answered "don't understand" and "correct me" practice questions, practice appeared to give no greater benefit than just hearing the rules. Results suggest that the current format of ground rule practice in interview guidelines is appropriate for the "don't know" rule, but the other rules may require more extensive practice with this age group. Copyright © 2015 John Wiley & Sons, Ltd.

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In spite of the increased use of factor-augmented regressions in recent years, little is known regarding the relative merits of the two main approaches to estimation and inference, namely, the cross-sectional average and principal component estimators. By providing a formal comparison of the approaches, the current paper fills this gap in the literature.

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The bulk of existing work on the statistical forecasting of air quality is based on either neural networks or linear regressions, which are both subject to important drawbacks. In particular, while neural networks are complicated and prone to in-sample overfitting, linear regressions are highly dependent on the specification of the regression function. The present paper shows how combining linear regression forecasts can be used to circumvent all of these problems. The usefulness of the proposed combination approach is verified using both Monte Carlo simulation and an extensive application to air quality in Bogota, one of the largest and most polluted cities in Latin America. © 2014 Elsevier Ltd.

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Most empirical evidence suggests that the Fisher effect, stating that inflation and nominal interest rates should cointegrate with a unit slope on inflation, does not hold, a finding at odds with many theoretical models. This paper argues that these results can be attributed in part to the low power of univariate tests, and that the use of panel data can generate more powerful tests. For this purpose, we propose two new panel cointegration tests that can be applied under very general conditions, and that are shown by simulation to be more powerful than other existing tests. These tests are applied to a panel of quarterly data covering 20 OECD countries between 1980 and 2004. The evidence suggest that the Fisher effect cannot be rejected once the panel evidence on cointegration has been taken into account. Copyright © 2008 John Wiley & Sons, Ltd.

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This article proposes a bias-adjusted estimator for use in cointegrated panel regressions when the errors are cross-sectionally correlated through an unknown common factor structure. The asymptotic distribution of the new estimator is derived and is examined in small samples using Monte Carlo simulations. For the estimation of the number of factors, several information-based criteria are considered. The simulation results suggest that the new estimator performs well in comparison to existing ones. In our empirical application, we provide new evidence suggesting that the forward rate unbiasedness hypothesis cannot be rejected. © The Author 2007.

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This paper examines the small-sample performance of several information based criteria that can be employed to facilitate data dependent endogeneity correction in estimation of cointegrated panel regressions. The Monte Carlo evidence suggests that the criteria generally perform well but that there are differences of practical importance. In particular, the evidence suggests that, although the estimators of the cointegration vectors generally perform well, the criterion with best small-sample performance also leads to the best performing estimator. © Blackwell Publishing Ltd, 2005.