A new type of double function optical circulator for double fibers is proposed in this paper. Two fiber tips and lens twice are employed in this kind of device as the coupling system for what is believed to be the fir...A new type of double function optical circulator for double fibers is proposed in this paper. Two fiber tips and lens twice are employed in this kind of device as the coupling system for what is believed to be the first time. Because two fiber tips and lens twice are used, the function of optical circulator is duplicated in comparison with conventional optical circulator with single fiber tip. Thus the optical circulator has a low cost and a small volume comparatively. Excess loss of the coupling system and the misalignment of the lens twice in angular error and the position error to the developed circulator are analyzed and discussed by using Gauss wave and double integral in theory. The analysis results show that the excess loss is zero when each distance is equal to f between every adjacent： fraction and without misalignment error in the coupling system. In addition, the excess loss is increasing with increment of the distance error and the angular error. The errors of the angular of the optical axis to lens and the distance between the SL to lens are the main source of the excess loss. The higher the errors are, the higher the excess loss is. It＇s very important for reducing the misalignment errors in the coupling system with high ratio of coupling to achieve low excess loss. Details of design and excess loss in the coupling system of this circulator are presented.展开更多
<strong>Background:</strong> In the treatment of morbid obesity bariatric surgery has become the method of choice. Dopamine is the primary modulator of the brain’s reward system and plays an essential rol...<strong>Background:</strong> In the treatment of morbid obesity bariatric surgery has become the method of choice. Dopamine is the primary modulator of the brain’s reward system and plays an essential role in the regulation of food intake. The role of dopamine is well documented in weight regulation and food intake in both animal models and humans. Still, the role of dopamine has not been well studied for weight loss. Catechol-O-methyltransferase (COMT) degrades catecholamines and estrogens are both known to be important risk factors for cardiovascular diseases and consequently obesity. The gene coding for COMT contains a Val108/158Met polymorphism that exerts a considerable influence on enzymatic activity. We hypothesized that this polymorphism might influence weight loss in obese patients, who previously underwent gastric banding surgery. In obesity research, it is known that women tend to lose more weight than men, and weight before surgery might also affect the outcome of weight loss efforts. Several studies have shown that physical activity (PA) plays an important role in maintaining weight as well as in both non-surgical and surgical weight loss. Therefore, we examined whether gender, age, weight before surgery and PA are good predictor variables for the outcome of surgical weight loss. <strong>Methods:</strong> One to six years after bariatric surgery 74 adults underwent a semi-structured interview. In a second step data on the post-surgical PA level were collected with the Moorehead-Ardelt Quality of Life Questionnaire. Finally, mouth swabs were used for genotyping. <strong>Results:</strong> 54 women and 20 men were enrolled between January 2004 and September 2009. Short-term EWL in the mid-activity genotype dopamine group (GA) was significantly higher (p = 0.007) than was short-term EWL in the low-activity genotype dopamine group (AA) or in the high-activity genotype dopamine group (GG). However, there were no significant differences between the COMT groups with respect to long-term EWL. Long-term we determined that EWL is significantly positively influenced by PA and negatively by gender. The effect of EWL was more pronounced in female than in male subjects. <strong>Conclusion:</strong> Various individual genotypes of the COMT polymorphism (Val108/158Met) make an impact only on short-term EWL, but not on long-term EWL. However, gender and PA proved to be good surgical weight loss predictors for long-term EWL.展开更多
The rharginal recursive equations on excess-of-loss reinsurance treaty are investignted, under the assumption that the number of claims belongs to the family consisting of Poisson, binomial and negative binomial, and ...The rharginal recursive equations on excess-of-loss reinsurance treaty are investignted, under the assumption that the number of claims belongs to the family consisting of Poisson, binomial and negative binomial, and that the severity distribution has bounded continuous density function. On conditional of the numbers of claims associated with the reinsurer and the cedent, some recursive equations are obtained for the marginal distributions of the total payments of the reinsurer and the cedent.展开更多
文摘A new type of double function optical circulator for double fibers is proposed in this paper. Two fiber tips and lens twice are employed in this kind of device as the coupling system for what is believed to be the first time. Because two fiber tips and lens twice are used, the function of optical circulator is duplicated in comparison with conventional optical circulator with single fiber tip. Thus the optical circulator has a low cost and a small volume comparatively. Excess loss of the coupling system and the misalignment of the lens twice in angular error and the position error to the developed circulator are analyzed and discussed by using Gauss wave and double integral in theory. The analysis results show that the excess loss is zero when each distance is equal to f between every adjacent： fraction and without misalignment error in the coupling system. In addition, the excess loss is increasing with increment of the distance error and the angular error. The errors of the angular of the optical axis to lens and the distance between the SL to lens are the main source of the excess loss. The higher the errors are, the higher the excess loss is. It＇s very important for reducing the misalignment errors in the coupling system with high ratio of coupling to achieve low excess loss. Details of design and excess loss in the coupling system of this circulator are presented.
文摘<strong>Background:</strong> In the treatment of morbid obesity bariatric surgery has become the method of choice. Dopamine is the primary modulator of the brain’s reward system and plays an essential role in the regulation of food intake. The role of dopamine is well documented in weight regulation and food intake in both animal models and humans. Still, the role of dopamine has not been well studied for weight loss. Catechol-O-methyltransferase (COMT) degrades catecholamines and estrogens are both known to be important risk factors for cardiovascular diseases and consequently obesity. The gene coding for COMT contains a Val108/158Met polymorphism that exerts a considerable influence on enzymatic activity. We hypothesized that this polymorphism might influence weight loss in obese patients, who previously underwent gastric banding surgery. In obesity research, it is known that women tend to lose more weight than men, and weight before surgery might also affect the outcome of weight loss efforts. Several studies have shown that physical activity (PA) plays an important role in maintaining weight as well as in both non-surgical and surgical weight loss. Therefore, we examined whether gender, age, weight before surgery and PA are good predictor variables for the outcome of surgical weight loss. <strong>Methods:</strong> One to six years after bariatric surgery 74 adults underwent a semi-structured interview. In a second step data on the post-surgical PA level were collected with the Moorehead-Ardelt Quality of Life Questionnaire. Finally, mouth swabs were used for genotyping. <strong>Results:</strong> 54 women and 20 men were enrolled between January 2004 and September 2009. Short-term EWL in the mid-activity genotype dopamine group (GA) was significantly higher (p = 0.007) than was short-term EWL in the low-activity genotype dopamine group (AA) or in the high-activity genotype dopamine group (GG). However, there were no significant differences between the COMT groups with respect to long-term EWL. Long-term we determined that EWL is significantly positively influenced by PA and negatively by gender. The effect of EWL was more pronounced in female than in male subjects. <strong>Conclusion:</strong> Various individual genotypes of the COMT polymorphism (Val108/158Met) make an impact only on short-term EWL, but not on long-term EWL. However, gender and PA proved to be good surgical weight loss predictors for long-term EWL.
基金Project supported by the National Natural Science Foundation of China (Nos. 10471008, 19831020)
文摘The rharginal recursive equations on excess-of-loss reinsurance treaty are investignted, under the assumption that the number of claims belongs to the family consisting of Poisson, binomial and negative binomial, and that the severity distribution has bounded continuous density function. On conditional of the numbers of claims associated with the reinsurer and the cedent, some recursive equations are obtained for the marginal distributions of the total payments of the reinsurer and the cedent.
