Cow-level evaluation of a kinetics ELISA with multiple cutoff values to detect fecal shedding of Mycobacterium avium subspecies paratuberculosis in New York State dairy cows

In control programs for Mycobacterium avium subsp. paratuberculosis (Map), the infection status of the cows in a herd is often obtained by testing (a sample of) the herd with an ELISA that may lack some sensitivity and specificity but that is fast and inexpensive. In New York State (NYS), an unabsorbed kinetics ELISA (KELA) has been used extensively for Map control. The objective of this study was to determine the relative sensitivity and specificity of the KELA for detection of fecal shedding of Map for the NYS dairy cow population, taking into account possible confounders such as different antigen batches and Map prevalence in a herd.

The data for the study consisted of all serum samples from NYS dairy cows with concurrent fecal culture results submitted to the NY Animal Health Diagnostic Laboratory (NYAHDL) between 1991 and 1996 (n = 10,562). The data represented cows with different levels of fecal shedding from herds with different within-herd Map prevalence, including herds that were whole herd fecal culture negative on repeated testing.

The cutoff values were based on the predictive value for fecal shedding obtained with a multiple logistic regression model that included variables for the three antigen batches and the Map prevalence in the herd. The KELA could not distinguish between non-shedders and low shedders (≤30 total colony forming units (TCFU)) and thus the predictive value of the KELA to detect moderate to heavy fecal shedders (>30 TCFU) was modeled. The three cutoff values of 65, 135 and 170 were based on low (<0.2), moderate (<0.80) and high (>0.95) probabilities for moderate to heavy fecal shedding. The sensitivity and specificity values relative to culture were 67% and 95.2%, 31% and 99.7%, and 11% and 99.9% for the three cutoff values, respectively. Cutoff values for the KELA decreased for herds with increasing within-herd Map prevalence. For the best positive predictive value of a KELA for moderate to heavy fecal shedding, the cutoff values should be determined based on the apparent within-herd prevalence in a herd.     

大学生村官胜任力模型构建研究

综合采用文献分析、理论研究和深度访谈等方法,从政治思想、心理品质、知识和能力等4个维度初步构建包含25项要素的大学生"村官"胜任力模型。在此基础上,科学设计大学生"村官"胜任力调查问卷,运用SPSS和LISREL软件对调查所得数据进行信度和效度分析,以此对模型加以验证。分析结果表明,该模型具有较强的科学性与合理性,符合预先的理论构想。     

大黄有效期的研究

[目的]对中药材大黄的有效期进行研究.[方法]选用易氧化变色的大黄,通过经典恒温试验,采用HPLC测定大黄酸、大黄素、大黄素甲醚、芦荟大黄素的含量,并研究该药有效成分含量的变化规律.[结果]经典恒温法测定的大黄酸、大黄素、大黄素甲醚、芦荟大黄素含量变化符合一级反应规律.在20℃的储藏条件下,大黄有效成分的含量变化速度常数为K=1.585×10-5,该批大黄有效期为687 d.[结论]用经典恒温法预测中药材大黄有效期,结论可靠.     

基于CVM的耕地保护外部性估算与检验

为了科学评估耕地保护的外部性, 在耕地利用效益体系重构和耕地保护外部性界定的基础上, 基于条件价值评估法(CVM)构建了耕地保护外部性测度、分析和检验一体化的方法体系, 并以河南省焦作市为研究区域进行了实证应用。研究结果表明: ①耕地生态社会效益属于一种纯粹的、具有正外部性和私人(主要为农户)联合提供的混合类跨区域性公共物品, 可以运用CVM等非市场价值评估法进行估算。②受访者的支付意愿较大程度地受社会经济发展水平的制约和影响, 农户和城镇居民对耕地生态社会效益认知度的高低是造成城镇居民与农户支付率差异的重要影响因素。③基于CVM测算出的焦作市耕地整体外部性为1.91亿元·a^-1, 耕地保护外部性为993.7元·hm^-2·a^-1, 该测算结果可作为耕地保护外部性补偿的最低标准。④CVM的有效性与可靠性检验是CVM理论、方法和实践内容的重要组成部分, 可通过问卷设计优化、预调查、问卷内容修正、合理的询价方式、不同估算方法的对照分析、同一方法重复试验等手段进行有效性与可靠性检验; 检验结果表明, CVM进行耕地保护外部性估算的可靠性和有效性较高。     

基于CVM的耕地保护外部性估算与检验

为了科学评估耕地保护的外部性,在耕地利用效益体系重构和耕地保护外部性界定的基础上,基于条件价值评估法(CVM)构建了耕地保护外部性测度、分析和检验一体化的方法体系,并以河南省焦作市为研究区域进行了实证应用。研究结果表明:1耕地生态社会效益属于一种纯粹的、具有正外部性和私人(主要为农户)联合提供的混合类跨区域性公共物品,可以运用CVM等非市场价值评估法进行估算。2受访者的支付意愿较大程度地受社会经济发展水平的制约和影响,农户和城镇居民对耕地生态社会效益认知度的高低是造成城镇居民与农户支付率差异的重要影响因素。3基于CVM测算出的焦作市耕地整体外部性为1.91亿元·a-1,耕地保护外部性为993.7元·hm-2·a-1,该测算结果可作为耕地保护外部性补偿的最低标准。4CVM的有效性与可靠性检验是CVM理论、方法和实践内容的重要组成部分,可通过问卷设计优化、预调查、问卷内容修正、合理的询价方式、不同估算方法的对照分析、同一方法重复试验等手段进行有效性与可靠性检验;检验结果表明,CVM进行耕地保护外部性估算的可靠性和有效性较高。     

土壤无机磷形态及有效性研究进展

综述了国内外近几年来土壤无机磷形态及有效性的研究进展,介绍了影响土壤无机磷形态及其转化固定和有效性的因子,并对土壤无机磷的转化固定机制作了简要论述。     

模糊集对分析中对立刻划的有效性分析

模糊熵函数适合于度量模糊集合的模糊度，本文利用模糊熵定义了模糊集对分析中的两次对立刻划的有效度，并作了初步分析．     

Participatory analysis of seasonal incidences of diseases of cattle, disease vectors and rainfall in southern Sudan

During an investigation into a chronic wasting disease in southern Sudanese cattle, a participatory appraisal method called a ‘seasonal calendar’ was used to understand local perceptions of seasonal variations in cattle diseases, disease vectors, intermediate hosts and rainfall. Repetition of a standardized seasonal calendar with Dinka informants demonstrated good reproducibility of the method. Comparison of rainfall data produced by seasonal calendars and objective measures of rainfall demonstrated good validity of the seasonal calendar method. Subjective assessment of seasonal calendar scoring patterns by veterinarians indicated that herders’ perceptions of seasonal populations of biting flies, ticks and snails were similar to modern veterinary knowledge. The uses of seasonal calendars in veterinary epidemiology are discussed.     

Diagnostic validity of cervical precancerous lesions by liquid-based cytology technique combined with high-risk HPV-DNA detection

AIM: To investigate liquid-based cytology technique (LCT) combined with high-risk human papilloma virus DNA (HPV-DNA) detection for diagnosis of cervical precancerous lesions. METHODS: Screening of cervical cancer was performed by LCT combined with HPV-DNA detection in 6 521 women at the age of 19~65 in our hospital for physical examination from December 2007 to December 2010. Eighteen high-risk HPV isoform genes were detected by HPV typing gene chip detection system. The women with positive detection underwent colposcopic cervical biopsies. The women with negative detection also underwent colposcopic cervical biopsies if the operation was of their own accord. RESULTS: The LCT positive results (≥ASCUS) were observed in 152 cases and HPV positive results were obtained in 86 cases. The women with both 2 positive results were found in 42 cases. The women with both LCT and HPV negative results were determined in 6 325 cases. In 152 cases of LCT positive and 86 cases of HPV positive women, the positive results of pathological biopsy (≥CINI) were 112 and 68 cases, respectively. Thirty-four cases in the 42 cases of both LCT and HPV positive women were conformed by pathological biopsy. In 6 325 women with negative results of LCT and HPV detection, 2 000 were perform pathological biopsy according to their own accord and only 1 had positive result. The diagnostic sensitivity of LCT for cervical precancerous lesions was 76.19% with the specificity of 98.05%. The diagnostic sensitivity of HPV detection for precancerous lesions of uterine cervix was 46.26% with the specificity of 99.12%. Combination of the 2 methods to diagnose cervical precancerous lesions made the sensitivity increase to 99.32% with the specificity of 99.61%. CONCLUSION: Liquid-based cytology technique combined with high-risk HPV-DNA detection is better than each of the single technique for screening precancerous lesion of cervical carcinoma.     

Comparison between dairy cow disease incidence in data registered by farmers and in data from a disease-recording system based on veterinary reporting

Sweden has a national disease-recording system based on veterinary reporting. From this system, all cattle-disease records are transferred to the dairy industry cattle database (DDD) where they are used for several purposes including research and dairy-health statistics. Our objective was to evaluate the completeness of this data source by comparing it with disease data registered by dairy farmers. The proportion of veterinary-treated disease events was estimated, by diagnosis. Disease incidence in the DDD was compared, by diagnosis and age, with disease data registered by the farmers. Comparison was made, by diagnosis, for (i) all disease events and (ii) those reported as veterinary-treated.Disease events, defined as “observed deviations in health, from the normal” were recorded by the farmers during January, April, July and October 2004. For the diagnoses calving problems, peripartum disorders, puerperal paresis and retained placenta, incidence proportions (IP) with 95% confidence intervals (CIs) were estimated. For all other disease problems, incidence rates (IR) were used.In total, 177 farmers reported at least 1 month and 148 reported all 4 months. Fifty-four percent of all disease events in the farmers’ data were reported as veterinary-treated. For several of the most common diagnoses, the IRs and IPs for all events were significantly higher in farmers’ data than in the DDD. Examples are, in cows: clinical mastitis, cough, gastro-intestinal disorders and lameness in hoof and limb; and in young stock: cough and gastro-intestinal disorders. For veterinary-treated events only, significant differences with higher IR in the farmers’ data were found in young stock for sporadic cough and sporadic gastro-intestinal disorders. The diagnosis “other disorders” had significantly more events in the DDD than in farmers’ data, i.e. veterinarians tended to choose more unspecific diagnoses than the farmers. This result indicates that the true completeness is likely to be higher than our estimate.We conclude that for the time period studied there was differential under-reporting associated with the diagnosis, the age of the animal and whether the herd was served by a state-employed or private veterinarian.