Myopia is a significant public health problem and its prevalence is increasing over time and genetic factors in disease development are important. The prevalence and incidence of myopia within sampled population often...Myopia is a significant public health problem and its prevalence is increasing over time and genetic factors in disease development are important. The prevalence and incidence of myopia within sampled population often varies with age, country, sec race, ethnicity, occupation, environment, and other factors. Myopia growth is under a combination of genes and their products in time and space to complete the coordination role of the guidance. Myopia-related genes include about 70 genetic loci to which primary myopias have been mapped, although the number is constantly increasing and depends to some extent on definition. Of these, several are associated with additional abnormalities, mostly as part of developmental syndromes. These tend to result from mutations in genes encoding transcriptional activators, and most of these have been identified by sequencing candidate genes in patients with developmental anomalies. Currently, collagen alpha-1 chain of type I(COL1A1), collagen alpha-1 chain of type II(COL2A1), actin, alpha, cardiac muscle 1 (ACTC1), paired box gene 6 (PAX6) and NIPBL (nipped-B homolog), and so on have been mapped. Myopia is most commonly treated with spectacles or glasses. The most common surgical procedure performed to correct myopia is laser keratomileusis (LASIK). This review of the recent advances on epidemiology, genetic locations and treatments of myopia are summarized.展开更多
In refractive surgery, the cubic spline fit for the transition zone breaks down for myopia and myopic meridians in mixed astigmatism as in many cases the cubic spline function runs into negative values. In this paper,...In refractive surgery, the cubic spline fit for the transition zone breaks down for myopia and myopic meridians in mixed astigmatism as in many cases the cubic spline function runs into negative values. In this paper, the complementary error function is proposed instead of the cubic spline function as the transition zone function, due to the availability of analytical expression of its derivatives and the nonnegativity fact. It is shown that with the use of the complementary error function, transition zones for all refractive types work correctly.展开更多
This study investigated the effects of different error treatments—overt correction and self-correction—on the usage of English tenses of Thai undergraduate students. Both treatments were given through CALL. Levels o...This study investigated the effects of different error treatments—overt correction and self-correction—on the usage of English tenses of Thai undergraduate students. Both treatments were given through CALL. Levels of the students (High, Moderate, and Low) served as a moderator variable. The study was conducted with 219 first-year undergraduates of Huachiew Chalermprakiet University in a 2x3 factorial design. At the beginning of the study, all subjects were pre-tested by using the Test of English Tenses Usage (TETU) developed by the researcher. After they completed 9 CALL lessons in 3 weeks, the post-test was conducted. Two-way Analysis of Variance (ANOVA) and descriptive statistics were used to analyze and to explain the data. Results showed that the error treatment factor did not have a significant effect on the usage of tenses while the level factor did. The interaction effect between the treatment and the level was not found. The three tenses that showed the highest percentage of correct answers: Simple Present, Present Continuous, and Past Continuous, while the most difficult tenses for them were Present Perfect and Past Perfect.展开更多
Usually, Chinese EFL students make satisfactory progress in reading, grammar and writing. However, it is very difficult for them to transmit messages, exchange thoughts in English. I conducted a questionnaire in Inner...Usually, Chinese EFL students make satisfactory progress in reading, grammar and writing. However, it is very difficult for them to transmit messages, exchange thoughts in English. I conducted a questionnaire in Inner Mongolia Teachers’ University and found out that when the students come to speak English, they tend to appear frustrated, lack confidence on the grounds of fear of making errors, which may be closely related to the teachers’ attitudes towards students’ errors. Therefore, it is essential for English teachers to have proper attitudes to errors in English teaching. The paper discusses some important strategies on whether, when and how speaking errors should be corrected based on some researchers’ views and on a small scale of experiment for the purpose of helping teachers deal with students’ errors effectively in communication.展开更多
Consider an observed binary regressor D and an unobserved binary vari- able D＊, both of which affect some other variable Y. This paper considers nonpara- metric identification and estimation of the effect of D on Y, ...Consider an observed binary regressor D and an unobserved binary vari- able D＊, both of which affect some other variable Y. This paper considers nonpara- metric identification and estimation of the effect of D on Y, conditioning on D＊ = 0. For example, suppose Y is a person＇s wage, the unobserved D＊ indicates if the person has been to college, and the observed D indicates whether the individual claims to have been to college. This paper then identifies and estimates the difference in av- erage wages between those who falsely claim college experience versus those who tell the truth about not having college. We estimate this average effect of lying to be about 6% to 20%. Nonparametric identification without observing D＊ is obtained ei- ther by observing a variable V that is roughly analogous to an instrument for ordinary measurement error, or by imposing restrictions on model error moments.展开更多
文摘Myopia is a significant public health problem and its prevalence is increasing over time and genetic factors in disease development are important. The prevalence and incidence of myopia within sampled population often varies with age, country, sec race, ethnicity, occupation, environment, and other factors. Myopia growth is under a combination of genes and their products in time and space to complete the coordination role of the guidance. Myopia-related genes include about 70 genetic loci to which primary myopias have been mapped, although the number is constantly increasing and depends to some extent on definition. Of these, several are associated with additional abnormalities, mostly as part of developmental syndromes. These tend to result from mutations in genes encoding transcriptional activators, and most of these have been identified by sequencing candidate genes in patients with developmental anomalies. Currently, collagen alpha-1 chain of type I(COL1A1), collagen alpha-1 chain of type II(COL2A1), actin, alpha, cardiac muscle 1 (ACTC1), paired box gene 6 (PAX6) and NIPBL (nipped-B homolog), and so on have been mapped. Myopia is most commonly treated with spectacles or glasses. The most common surgical procedure performed to correct myopia is laser keratomileusis (LASIK). This review of the recent advances on epidemiology, genetic locations and treatments of myopia are summarized.
文摘In refractive surgery, the cubic spline fit for the transition zone breaks down for myopia and myopic meridians in mixed astigmatism as in many cases the cubic spline function runs into negative values. In this paper, the complementary error function is proposed instead of the cubic spline function as the transition zone function, due to the availability of analytical expression of its derivatives and the nonnegativity fact. It is shown that with the use of the complementary error function, transition zones for all refractive types work correctly.
文摘This study investigated the effects of different error treatments—overt correction and self-correction—on the usage of English tenses of Thai undergraduate students. Both treatments were given through CALL. Levels of the students (High, Moderate, and Low) served as a moderator variable. The study was conducted with 219 first-year undergraduates of Huachiew Chalermprakiet University in a 2x3 factorial design. At the beginning of the study, all subjects were pre-tested by using the Test of English Tenses Usage (TETU) developed by the researcher. After they completed 9 CALL lessons in 3 weeks, the post-test was conducted. Two-way Analysis of Variance (ANOVA) and descriptive statistics were used to analyze and to explain the data. Results showed that the error treatment factor did not have a significant effect on the usage of tenses while the level factor did. The interaction effect between the treatment and the level was not found. The three tenses that showed the highest percentage of correct answers: Simple Present, Present Continuous, and Past Continuous, while the most difficult tenses for them were Present Perfect and Past Perfect.
文摘Usually, Chinese EFL students make satisfactory progress in reading, grammar and writing. However, it is very difficult for them to transmit messages, exchange thoughts in English. I conducted a questionnaire in Inner Mongolia Teachers’ University and found out that when the students come to speak English, they tend to appear frustrated, lack confidence on the grounds of fear of making errors, which may be closely related to the teachers’ attitudes towards students’ errors. Therefore, it is essential for English teachers to have proper attitudes to errors in English teaching. The paper discusses some important strategies on whether, when and how speaking errors should be corrected based on some researchers’ views and on a small scale of experiment for the purpose of helping teachers deal with students’ errors effectively in communication.
文摘Consider an observed binary regressor D and an unobserved binary vari- able D＊, both of which affect some other variable Y. This paper considers nonpara- metric identification and estimation of the effect of D on Y, conditioning on D＊ = 0. For example, suppose Y is a person＇s wage, the unobserved D＊ indicates if the person has been to college, and the observed D indicates whether the individual claims to have been to college. This paper then identifies and estimates the difference in av- erage wages between those who falsely claim college experience versus those who tell the truth about not having college. We estimate this average effect of lying to be about 6% to 20%. Nonparametric identification without observing D＊ is obtained ei- ther by observing a variable V that is roughly analogous to an instrument for ordinary measurement error, or by imposing restrictions on model error moments.
