The objective of Performance-Based Earthquake Engineering （PBEE） is the analysis of performance objectives with a specified annual probability of exceedance. Increasingly undesirable performance is caused by increas...The objective of Performance-Based Earthquake Engineering （PBEE） is the analysis of performance objectives with a specified annual probability of exceedance. Increasingly undesirable performance is caused by increasing levels of strong ground motion having decreasing annual probabilities of exceedance. The development of this methodology includes three steps： （1） evaluation of the distribution of ground motion at a site; （2） evaluation of the distribution of system response; （3） evaluation of the probability of exceeding decision variables within a given time period, given appropriate damage measures. The work has taken a systematic approach to determine the impact of increasing levels of detail in site characterization on the accuracy of ground motion and site effects predictions. Complementary studies have investigated the use of the following models for evaluating site effects： （1） amplification factors defined on the basis of generalized site categories, （2） one-dimensional ground response analysis, and （3） two-dimensional ground response analysis for surface topography on ground motion. The paper provides a brief synthesis of ground motion and site effects analysis procedures within a Performance-Based Design framework. It focuses about the influence on the evaluation of site effects in some active regions by different shear waves velocity measurements Down Hole （D-H）, Cross Hole （C-H）, Seismic Dilatometer Marchetti Test （SDMT） and by different variation of shear modulus and damping ratio with strain level and depth from different laboratory dynamic tests for soil characterization： Resonant Column Test （RCT）, Cyclic Loading Torsional Shear Test （CLTST）.展开更多
AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscop...AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscopy within 72 h were enrolled. Clinical and basic laboratory parameters were prospectively collected. Predictive factors for the types of UGIB were identified by univariate and multivariate analyses and were used to generate the UGIB Etiology Score. The best cutoff of the score was defined from the receiver operating curve and prospectively validated in another set of patients with UGIB. RESULTS： Among 261 patients with UGIB, 47 （18%） had variceal and 214 （82%） had non-variceal bleeding. Univariate analysis identified 27 distinct parameters significantly associated with the types of UGIB. Logistic regression analysis identified only 3 independent factors for predicting variceal bleeding; previous diagnosis of cirrhosis or signs of chronic liver disease （OR 22.4, 95% CI 8.3-60.4, P 〈 0.001）, red vomitus （OR 4.6, 95% CI 1.8-11.9, P = 0.02）, and red nasogastric （NG） aspirate （OR 3.3, 95% CI 1.3-8.3, P = 0.011）. The UGIB Etiology Score was calculated from （3.1× previous diagnosis of cirrhosis or signs of chronic liver disease） ＋ （1.5× red vomitus） ＋ （1.2× red NG aspirate）, when 1 and 0 are used for the presence and absence of each factor, respectively. Using a cutoff ≥ 3.1, the sensitivity, specificity, accuracy, positive predictive value （PPV）, and negative predictive value （NPV） in predicting variceal bleeding were 85%, 81%, 82%, 50%, and 96%, respectively. The score was prospectively validated in cases （46 variceal and 149 another set of 195 UGIB non-variceal bleeding）. The PPV and NPV of a score ≥ 3.1 for variceal bleeding were 79% and 97%, respectively. CONCLUSION： The UGIB Etiology Score, composed of 3 parameters, using a cutoff ≥ 3.1 accurately predicted variceal bleeding and may help to guide the choice of initial therapy for UGIB before endoscopy.展开更多
The purpose of this research is to identify and examine the achievement gaps between students. Over the past thirty years, emphasis has been placed on achievement levels of students in this country. State test results...The purpose of this research is to identify and examine the achievement gaps between students. Over the past thirty years, emphasis has been placed on achievement levels of students in this country. State test results, SAT Scores, ACT scores and other assessment instruments have been used to determine performance standards and test results for students. Data analyzed for White students compared to African American and Hispanic students have provided critical information in identifying academic progress and skill deficits for all students. This article will highlight some of the achievement gaps which exit among White, African American and Hispanic Students. Recommendations will also be emphasized to help improve student achievement levels in an effort to close the achievement gap.展开更多
文摘The objective of Performance-Based Earthquake Engineering （PBEE） is the analysis of performance objectives with a specified annual probability of exceedance. Increasingly undesirable performance is caused by increasing levels of strong ground motion having decreasing annual probabilities of exceedance. The development of this methodology includes three steps： （1） evaluation of the distribution of ground motion at a site; （2） evaluation of the distribution of system response; （3） evaluation of the probability of exceeding decision variables within a given time period, given appropriate damage measures. The work has taken a systematic approach to determine the impact of increasing levels of detail in site characterization on the accuracy of ground motion and site effects predictions. Complementary studies have investigated the use of the following models for evaluating site effects： （1） amplification factors defined on the basis of generalized site categories, （2） one-dimensional ground response analysis, and （3） two-dimensional ground response analysis for surface topography on ground motion. The paper provides a brief synthesis of ground motion and site effects analysis procedures within a Performance-Based Design framework. It focuses about the influence on the evaluation of site effects in some active regions by different shear waves velocity measurements Down Hole （D-H）, Cross Hole （C-H）, Seismic Dilatometer Marchetti Test （SDMT） and by different variation of shear modulus and damping ratio with strain level and depth from different laboratory dynamic tests for soil characterization： Resonant Column Test （RCT）, Cyclic Loading Torsional Shear Test （CLTST）.
文摘AIM： To identify clinical parameters, and develop an Upper Gastrointesinal Bleeding （UGIB） Etiology Score for predicting the types of UGIB and validate the score. METHODS： Patients with UGIB who underwent endoscopy within 72 h were enrolled. Clinical and basic laboratory parameters were prospectively collected. Predictive factors for the types of UGIB were identified by univariate and multivariate analyses and were used to generate the UGIB Etiology Score. The best cutoff of the score was defined from the receiver operating curve and prospectively validated in another set of patients with UGIB. RESULTS： Among 261 patients with UGIB, 47 （18%） had variceal and 214 （82%） had non-variceal bleeding. Univariate analysis identified 27 distinct parameters significantly associated with the types of UGIB. Logistic regression analysis identified only 3 independent factors for predicting variceal bleeding; previous diagnosis of cirrhosis or signs of chronic liver disease （OR 22.4, 95% CI 8.3-60.4, P 〈 0.001）, red vomitus （OR 4.6, 95% CI 1.8-11.9, P = 0.02）, and red nasogastric （NG） aspirate （OR 3.3, 95% CI 1.3-8.3, P = 0.011）. The UGIB Etiology Score was calculated from （3.1× previous diagnosis of cirrhosis or signs of chronic liver disease） ＋ （1.5× red vomitus） ＋ （1.2× red NG aspirate）, when 1 and 0 are used for the presence and absence of each factor, respectively. Using a cutoff ≥ 3.1, the sensitivity, specificity, accuracy, positive predictive value （PPV）, and negative predictive value （NPV） in predicting variceal bleeding were 85%, 81%, 82%, 50%, and 96%, respectively. The score was prospectively validated in cases （46 variceal and 149 another set of 195 UGIB non-variceal bleeding）. The PPV and NPV of a score ≥ 3.1 for variceal bleeding were 79% and 97%, respectively. CONCLUSION： The UGIB Etiology Score, composed of 3 parameters, using a cutoff ≥ 3.1 accurately predicted variceal bleeding and may help to guide the choice of initial therapy for UGIB before endoscopy.
文摘The purpose of this research is to identify and examine the achievement gaps between students. Over the past thirty years, emphasis has been placed on achievement levels of students in this country. State test results, SAT Scores, ACT scores and other assessment instruments have been used to determine performance standards and test results for students. Data analyzed for White students compared to African American and Hispanic students have provided critical information in identifying academic progress and skill deficits for all students. This article will highlight some of the achievement gaps which exit among White, African American and Hispanic Students. Recommendations will also be emphasized to help improve student achievement levels in an effort to close the achievement gap.
