Screening of Serum Dilution and Determination of Normal Range of Antibodies against Rabies Viruses in Dog Sera

[ Objective] To screen a suitable serum dilution and determine the normal range of antibodies against rabies viruses （RV） in dog serum. [Method]A sensitive, specific and suitable serum dilution was screened. A total of 812 dog serum samples were collected from Changchun, Nanning and Uuzhou regions, and then they were diluted with above screened serum dilution and evaluated by indirect enzyme-linked immunosorbont assay （ELISA）. The positive and negative standard dog sara from the World Organization for Animal Health （OIE） were used as controls. The serum samples with different A450 were randomly selected and the anti-RV serum titers were detected by rapid fluorescent focus inhibition test （RFFIT）. According to the A450 of dog sera, the normal A450 range of negative serum and 95% confidence intervals were calculated with SPSS 10.0 software, and the regression equation of OIE standards was established. [ Result] The screened serum dilution was sensitive and specific; at least 756 negative serum samples were obtained; the normal range and 95% confidence interval of negative serum were 0.127 3 ± 0.059 8 and 0.078 1 -0.172 3, respectively; and the regression equation was A450 = 1.139 serum titer （IU） ±0.470. [ Conclusion] These results lay a foundation for thecontrolling of dog rabies endemic and the development of ELISA kits of dog antibodies against RV.

Feature Extraction of Radar Range Profiles Based on Normalized Central Moments

The normalized central moments are widely used in pattern recognition because of scale and translation invariance. The moduli of normalized central moments of the 1-dimensional complex range profiles are used here as feature vector for radar target recognition. The common feature extraction method for high resolution range profile obtained by using Fourier-modified direct Mellin transform is inefficient and unsatisfactory in recognition rate And. generally speaking, the automatic target recognition method based on inverse synthetic aperture radar 2-dimensional imaging is not competent for real time object identification task because it needs complicated motion compensation which is sometimes too difficult to carry out. While the method applied here is competent for real-time recognition because of its computational efficiency. The result of processing experimental data indicates that this method is good at recognition.

Heart Rate Distribution and Cause-specific Death in General Population of South China

Objectives To analyses heart rate （HR） distribution of healthy adults in the south China community and evaluate relative risk of HR to total cause of death and cardiac cerebral vascular death. Methods Analytical data come from the baseline survey and follow-up visits in the PRC-USA Collaborative Study of Cardiovascular Epidemiology in urban and rural samples of Guangzhou. The baseline survey was initiated in 1983 and 1984, and rescanned in 1987 and 1988. Since 1991 Follow-up visits for endpoint events were carried once every two years. Average follow-up year was 16.2 from baseline to 2000. People excluded from cardiac cerebral vascular disease, diabetes and other various chronic diseases were regarded as ＂healthy adults＂. Heart rates of these subjects were measured on resting electrocardiogram. Endpoint evens include： total cause of death, first attack of coronary disease and cerebral vascular events. SAS software was used for analysis. Cox Proportional Hazards model was used to evaluate the impact of HR on total death and cardiac cerebral vascular disease. Results A total of 4570 men and women aged 35-55 years from urban and rural Guangzhou were investigated. 3493 healthy subjects were enrolled in the analysis, including 1694 men and 1799 women. Mean oftheHRis （67.9 ±10.6） beats/min （bpm） in the whole population, （66.3±10.7）bpm in men and （69.3± 10.4） in women. The 52 percentile of the HR was 51 in men and 54 in women. The 952 percentile of the HR was 85 in men and 88 in women. Single correlation analysis showed there was negative relationship between age and HR, but it was only statistical significant in female. Analysis with Cox Proportional Hazards model show that HR 〈 50 bpm tops the risk of total causes of death （1.725）and HR 50-59 bpm decreased the risk of total causes of death （0.843）. Relative risk of cardiac cerebral vascular events exceeds 1 when HR 〈 50 and 〉90 bpm （1.486 and 7.008 respectively）. It was less than 1 in other groups but there was no significant difference between each group. Conclusions Traditional normal range of HR in adult should be adjusted. In certain extent lower HR is advantageous to decrease cardiac cerebral vascular events, total causes of death and has better prognosis.

Heart failure with reduced,mildly reduced,or preserved left ventricular ejection fraction:Has reasoning been lost?

Left ventricular(LV)ejection fraction(LVEF),defined as LV stroke volume divided by end-diastolic volume,has been systematically used for the diagnosis,classification,and management of heart failure(HF)over the last three decades.HF is classified as HF with reduced LVEF,HF with midrange or mildly reduced LVEF,and HF with preserved LVEF using arbitrary,continuously changing LVEF cutoffs.A prerequisite for using this LVEF-based terminology is knowledge of the LVEF normal range,which is lacking and may lead to erroneous conclusions in HF,especially at the higher end of the LVEF spectrum.