Consider a partially linear regression model with an unknown vector parameter , an unknown function g(·), and unknown heteroscedastic error variances. Chen, You<SUP>[23]</SUP> proposed a semiparametri...Consider a partially linear regression model with an unknown vector parameter , an unknown function g(·), and unknown heteroscedastic error variances. Chen, You<SUP>[23]</SUP> proposed a semiparametric generalized least squares estimator (SGLSE) for , which takes the heteroscedasticity into account to increase efficiency. For inference based on this SGLSE, it is necessary to construct a consistent estimator for its asymptotic covariance matrix. However, when there exists within-group correlation, the traditional delta method and the delete-1 jackknife estimation fail to offer such a consistent estimator. In this paper, by deleting grouped partial residuals a delete-group jackknife method is examined. It is shown that the delete-group jackknife method indeed can provide a consistent estimator for the asymptotic covariance matrix in the presence of within-group correlations. This result is an extension of that in [21].展开更多
Background: Laparoscopic hepatectomy for hepatocellular carcinoma(HCC) located in segment Ⅵ, Ⅶ, or Ⅷ of the liver is usually difficult because of poor operative exposure, due to the unique anatomical structure. In ...Background: Laparoscopic hepatectomy for hepatocellular carcinoma(HCC) located in segment Ⅵ, Ⅶ, or Ⅷ of the liver is usually difficult because of poor operative exposure, due to the unique anatomical structure. In this study, we evaluated the practice of laparoscopic hepatectomy with the left jackknife position for patients with HCC located in segment Ⅵ, Ⅶ, or Ⅷ.Methods: A total of 10 patients were enrolled to undergo laparoscopic hepatectomy with the left jackknife position.Tumors located in segment Ⅵ, Ⅶ, or Ⅷ were assessed by preoperative dynamic computed tomography or magnetic resonance imaging. Operation time, intraoperative blood loss, postoperative fasting time, postoperative drainage time, major postoperative complications, and duration of postoperative hospital stay were recorded.Results: All surgeries were successfully completed. None of the patients required conversion to open surgery during the procedure, and no serious postoperative complications were observed.The median tumor size was 31 mm(range 23-41 mm) in diameter, the mean operation time was 166 ± 38 min, the mean intraoperative blood loss was220 ± 135 mL, and the median postoperative hospital stay was 4 days(range 2-7 days).Conclusions: For HCC located in segment Ⅵ, Ⅶ, or Ⅷ, laparoscopic hepatectomy with this novel position—the left jackknife position—is safe and effective during tumor resection by exposing a sufficient operating field.Trial registration ClinicalTrials.gov ID:展开更多
The purpose of this study was to examine the burnout levels of research assistants in Ondokuz Mayis University and to examine the results of multiple linear regression model based on the results obtained from Maslach ...The purpose of this study was to examine the burnout levels of research assistants in Ondokuz Mayis University and to examine the results of multiple linear regression model based on the results obtained from Maslach Burnout Scale with Jackknife Method in terms of validity and generalizability. To do this, a questionnaire was given to 11 research assistants working at Ondokuz Mayis University and the burnout scores of this questionnaire were taken as the dependent variable of the multiple linear regression model. The variable of burnout was explained with the variables of age, weekly hours of classes taught, monthly average credit card debt, numbers of published articles and reports, gender, marital status, number of children and the departments of the research assistants. Dummy variables were assigned to the variables of gender, marital status, number of children and the departments of the research assistants and thus, they were made quantitative. The significance of the model as a result of multiple linear regressions was examined through backward elimination method. After this, for the five explanatory variables which influenced the variable of burnout, standardized model coefficients and coefficients of determination, and 95% confidence intervals of these values were estimated through Jackknife Method and the generalizability of the parameter estimation results of these variables on population was researched.展开更多
文摘Consider a partially linear regression model with an unknown vector parameter , an unknown function g(·), and unknown heteroscedastic error variances. Chen, You<SUP>[23]</SUP> proposed a semiparametric generalized least squares estimator (SGLSE) for , which takes the heteroscedasticity into account to increase efficiency. For inference based on this SGLSE, it is necessary to construct a consistent estimator for its asymptotic covariance matrix. However, when there exists within-group correlation, the traditional delta method and the delete-1 jackknife estimation fail to offer such a consistent estimator. In this paper, by deleting grouped partial residuals a delete-group jackknife method is examined. It is shown that the delete-group jackknife method indeed can provide a consistent estimator for the asymptotic covariance matrix in the presence of within-group correlations. This result is an extension of that in [21].
基金supported by the National Natural Science Foundation of China(No:81602143)
文摘Background: Laparoscopic hepatectomy for hepatocellular carcinoma(HCC) located in segment Ⅵ, Ⅶ, or Ⅷ of the liver is usually difficult because of poor operative exposure, due to the unique anatomical structure. In this study, we evaluated the practice of laparoscopic hepatectomy with the left jackknife position for patients with HCC located in segment Ⅵ, Ⅶ, or Ⅷ.Methods: A total of 10 patients were enrolled to undergo laparoscopic hepatectomy with the left jackknife position.Tumors located in segment Ⅵ, Ⅶ, or Ⅷ were assessed by preoperative dynamic computed tomography or magnetic resonance imaging. Operation time, intraoperative blood loss, postoperative fasting time, postoperative drainage time, major postoperative complications, and duration of postoperative hospital stay were recorded.Results: All surgeries were successfully completed. None of the patients required conversion to open surgery during the procedure, and no serious postoperative complications were observed.The median tumor size was 31 mm(range 23-41 mm) in diameter, the mean operation time was 166 ± 38 min, the mean intraoperative blood loss was220 ± 135 mL, and the median postoperative hospital stay was 4 days(range 2-7 days).Conclusions: For HCC located in segment Ⅵ, Ⅶ, or Ⅷ, laparoscopic hepatectomy with this novel position—the left jackknife position—is safe and effective during tumor resection by exposing a sufficient operating field.Trial registration ClinicalTrials.gov ID:
文摘The purpose of this study was to examine the burnout levels of research assistants in Ondokuz Mayis University and to examine the results of multiple linear regression model based on the results obtained from Maslach Burnout Scale with Jackknife Method in terms of validity and generalizability. To do this, a questionnaire was given to 11 research assistants working at Ondokuz Mayis University and the burnout scores of this questionnaire were taken as the dependent variable of the multiple linear regression model. The variable of burnout was explained with the variables of age, weekly hours of classes taught, monthly average credit card debt, numbers of published articles and reports, gender, marital status, number of children and the departments of the research assistants. Dummy variables were assigned to the variables of gender, marital status, number of children and the departments of the research assistants and thus, they were made quantitative. The significance of the model as a result of multiple linear regressions was examined through backward elimination method. After this, for the five explanatory variables which influenced the variable of burnout, standardized model coefficients and coefficients of determination, and 95% confidence intervals of these values were estimated through Jackknife Method and the generalizability of the parameter estimation results of these variables on population was researched.
