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应用不同醋酸地塞米松剂量和不同猪源隐孢子虫sucp株卵囊剂量建立了昆明系小鼠感染模型。结果表明,用DEX免疫抑制的感染小鼠均排出隐孢子虫卵囊,非免疫抑制感染组和空白对照组小鼠均没有排出卵囊。卵囊排出高峰期平均在感染后第5~12 d,高峰期的OPG值为5.53×105~17.97×105。组织切片和扫描电镜观察结果显示,在十二指肠、空肠和回肠都有隐孢子虫虫体寄生,其中回肠黏膜微绒毛上的虫体数量较多。合适的卵囊和DEX剂量为每只17日龄小白鼠感染10×105个猪源隐孢子虫卵囊和灌胃DEX 0.03 mg/d。 相似文献
3.
A growing body of research has linked exposure to violence to violent behavior, but few studies have examined the impact of the timing of exposure to violence on violent behavior among inner city, minority youth. Theoretical insights derived from developmental psychology and psychopathology (DPP) and Agnew’s general strain theory (GST) give contrasting accounts of whether exposure to violence has a short term or long term impact on violent behavior. Five waves of data collected from African American youth living in twelve high poverty inner city neighborhoods was used to examine how the timing of exposure to violence over a four year time period impacts year five violent behavior. Multivariate results support GST’s contention that more proximal exposure to violence has a larger impact on violent behavior. The theoretical and practical implications of the findings for adolescent development in high poverty settings are discussed.
相似文献
Richard SpanoEmail: |
4.
采用一步法长距离RT-PCR克隆了IBDV Gt株全基因组,对其核苷酸和氨基酸序列进行了系统分析。在IBDV Gt株全基因组中引入分子标签,且在基因组两端分别引入锤头状核酶结构(HamRz)和丁肝病毒核酶结构(HdvRz)。将带有分子标签和核酶结构的IBDV基因组插入载体pCAGGS的β肌动蛋白启动子下游,构建了IBDV真核表达载体pCAGGmGtAHRT和pCAG-GmGtBHRT,为IBDV新型高效拯救平台的构建及基于此的病毒基因功能奠定了基础。 相似文献
5.
From within an organizational strain perspective, this paper examines the effects of managerial succession, CEO background, decentralized management, and product dominant strategies on the reported corporate antitrust offending levels of 43 basic manufacturing companies over a 22-year period. In the aggregate, findings suggest that past illegal involvement predicts future offending; companies headed by finance and administrative CEOs have higher offending levels than do firms headed by CEOs from other backgrounds; a turnover in top management generally decreases offending levels; the pursuit of product dominant strategies increases the number of anticompetitive acts; and offending levels are unrelated to whether new leaders are recruited from within or outside the firm, whether the CEO is also Chair of the Board of Directors, or whether management is centralized or decentralized. The effects of some variables on corporate offending interact with firm performance. 相似文献
6.
Strain,Negative Emotions,and Deviant Coping Among African Americans: A Test of General Strain Theory
Although previous research on Agnew's (1992) general strain theory (GST) tends to yield significant effects of strain on negative emotions as well as deviance and crime, results tend to be mixed with regard to (1) the effects of negative emotions on deviance and crime and (2) conditioning factors that Agnew suggests affect the selection of coping strategies. To address these issues, we test hypotheses, derived from GST, about the relationships among strain, negative emotions, and deviant coping by analyzing data from a nationally representative sample of African American adults. Ordinary least squares regression results generally support our hypotheses. First, fully mediating the effects of strain on deviant coping, negative emotions have consistently significant effects on deviance, regardless of whether we use composite or separate measures of inner- and outer-directed emotions and deviance. Interestingly, as hypothesized, the same-directed effects of negative emotions on deviant coping are larger than the opposite-directed ones. Second, while self-esteem and self-efficacy as conditioning factors generally fail to receive empirical support, religiosity is found to significantly buffer the effects of negative emotions on deviance. Implications of our findings for further development of GST are discussed. 相似文献
7.
Robert Agnew 《Journal of Quantitative Criminology》1989,5(4):373-387
Agnew's (1985) revised strain theory argues that delinquency results from the inability to escape legally from painful or aversive situations. There is much indirect support for the theory, with experimental and survey data indicating that delinquency is associated with a wide variety of aversive situations. The experimental data, however, are of questionable generalizability and the survey data are primarily cross sectional in nature, leaving unresolved the issue of causal direction. This study examines the relationship between environmental adversity and delinquency using longitudinal data from a nationally representative sample of adolescent boys. A distribution-free method (arbitrary generalized least squares) is used to estimate a covariance structure model depicting a reciprocal relationship between adversity and delinquency. The results support the revised strain theory: environmental adversity has a causal effect on delinquency, but delinquency does not have an effect on adversity. 相似文献
8.
Swider C Maguire K Rickenbach M Montgomery M Ducote MJ Marhefka CA 《Journal of forensic sciences》2012,57(4):923-931
Following the September 11, 2001 terrorist attacks, letters containing Bacillus anthracis were distributed through the United States postal system killing five people. A complex forensic investigation commenced to identify the perpetrator of these mailings. A novel liquid chromatography/mass spectrometry protocol for the qualitative detection of trace levels of meglumine and diatrizoate in dried spore preparations of B. anthracis was developed. Meglumine and diatrizoate are components of radiographic imaging products that have been used to purify bacterial spores. Two separate chromatographic assays using multiple mass spectrometric analyses were developed for the detection of meglumine and diatrizoate. The assays achieved limits of detection for meglumine and diatrizoate of 1.00 and 10.0 ng/mL, respectively. Bacillus cereus T strain spores were effectively used as a surrogate for B. anthracis spores during method development and validation. This protocol was successfully applied to limited evidentiary B. anthracis spore material, providing probative information to the investigators. 相似文献
9.
《Justice Quarterly》2012,29(2):283-312
Hypotheses from General Strain theory are addressed using data from a random sample of adults in Raleigh, NC. Analyses examine three issues: (1) whether strain predicts self‐projected criminal behavior; controlling for past self‐reported crime; (2) whether negative emotions mediate the relationship between strain and projected crime; and (3) whether social support and criminal peers serve as contingencies or mediators for strain in predicting criminality. Results are generally consistent with previous studies focusing on youth. Three of four measures of strain are found to predict the crime measures. However, that relationship is not mediated by negative emotion and the measures of social support and criminal peers do not act as contingencies or mediators. The results suggest that strain may not operate through negative emotions and that theoretical refinement is needed to identify which potential contingencies are likely to be operating under various circumstances. 相似文献
10.
为研究绵羊睾丸支持细胞对山羊痘病毒的增殖特性,采用胶原酶Ⅳ和胰酶两步法分离绵羊睾丸支持细胞,通过倒置显微镜进行形态学观察、细胞染色鉴定以及特异性表达ABP蛋白鉴定,然后接种山羊痘病毒疫苗株。结果显示,分离的原代细胞24 h可长满单层,用0.05%的胰酶消化处理3次可得到纯度约为80%的睾丸支持细胞;油红O染色可观察到绵羊睾丸支持细胞的细胞质含有大量脂肪滴,细胞核可见双极小体;HE染色后细胞核为蓝色,细胞质呈红色或粉红色。ABP蛋白间接免疫荧光可观察到在绵羊睾丸支持细胞的细胞质和细胞核周围有绿色荧光,经显微镜下计数其纯度达80%以上。接种山羊痘病毒疫苗株后第4天有90%细胞产生病变,细胞变圆,细胞聚集成簇状,细胞收缩、细胞核出现空泡化。qPCR扩增Ct值为18.81,Ct值低于其他细胞传代数值。结论,本研究成功分离培养了绵羊睾丸支持细胞,该细胞能较好地培养山羊痘病毒疫苗株,对羊痘疫苗的生产有一定的现实意义。 相似文献