Dose-Response Model for 13 Strains of Salmonella

Data from a human feeding trial with healthy men were used to develop a dose-response model for 13 strains of Salmonella and to determine the effects of strain variation on the shape of the dose-response curve. Dose-response data for individual strains were fit to a three-phase linear model to determine minimum, median, and maximum illness doses, which were used to define Pert distributions in a computer simulation model. Pert distributions for illness dose of individual strains were combined in an Excel spreadsheet using a discrete distribution to model strain prevalence. In addition, a discrete distribution was used to model dose groups and thus create a model that simulated human feeding trials. During simulation of the model with @Risk, an illness dose and a dose consumed were randomly assigned to each consumption event in the simulated feeding trial and if the illness dose was greater than the dose consumed then the model predicted no illness, otherwise the model predicted that an illness would occur. To verify the dose-response model predictions, the original feeding trial was simulated. The dose-response model predicted a median of 69 (range of 43-101) illnesses compared to 74 in the original trial. Thus, its predictions were in agreement with the data used to develop it. However, predictions of the model are only valid for eggnog, healthy men, and the strains and doses of Salmonella used to develop it. When multiple strains of Salmonella were simulated together, the predicted dose-response curves were irregular in shape. Thus, the sigmoid shape of dose-response curves in feeding trials with one strain of Salmonella may not accurately reflect dose response in naturally contaminated food where multiple strains may be present.     

肇庆地区冬种马铃薯形态指标、光合速率与块茎产量相关性研究

对2种来源冬种马铃薯的形态指标、光合速率与块茎产量指标进行比较,并对其相关性进行研究.结果表明：冬种马铃薯的不同繁育株系在肇庆地区的地域适应性存在差异.冬种马铃薯的形态指标、光合速率及块茎产量均呈不同程度的正相关.采收前冬种马铃薯的株高、基径、根长、不定根数、叶片数、净光合速率、块茎数和块茎产量测定参数均可作为马铃薯产量的预测指标.     

早熟夏玉米高产杂交种主要农艺性状分析

通过对山东省70～80年代早熟夏玉米高产杂交种主要农艺性状的分析,认为高产杂交种产量潜力的增加主要是由于提高了籽粒的千粒重,增强了品种的抗病性和因株型紧凑而增加了密度,其次是增加了穗长和穗粒数,但与穗行数无关。今后,早熟玉米育种应以大粒、抗病和紧凑株型为主要目标。     

Bullying victimization,negative emotions,and substance use: utilizing general strain theory to examine the undesirable outcomes of childhood bullying victimization in adolescence and young adulthood

Bullying victimization has been directly associated with a variety of negative outcomes, but there are still many unknowns as to how deleterious emotional states resulting from victimization influence other undesirable events. The current study draws on Agnew’s general strain theory to examine multiple outcomes of youth victimized by repeated bullying prior to adolescence. Data from the National Longitudinal Survey of Youth 1997 were used to examine indicators of diminished moods and negative emotions on substance use for bullying victims in adolescence and again during young adulthood. Findings from various LISERL models indicate that bullying victimization directly increases diminished moods for males and females in adolescence. Additionally, childhood bullying victimization directly increases substance use in adolescence and young adulthood for males but not females. Finally, diminished moods in adolescence and negative emotions in young adulthood increase substance use for females but not for males. Policy implications and limitations for this analysis are discussed.     

Emotional labour,collectivism and strain: a comparison of Turkish and U.S. service employees

ABSTRACT

Global growth in service employment highlights the need to understand how cross-cultural differences impact emotional labour processes for service employees. The current study investigates these differences by examining the impact of national and individual level collectivistic values on emotional labour strategies and employee strain (emotional strain, turnover intentions, job satisfaction, and organisational commitment). Cross-sectional data was collected from U.S. (n?=?191) and Turkish (n?=?249) customer service employees. Results indicate that collectivism impacts the process model of emotional labour via direct and interaction effects. Collectivism was associated with higher emotional labour engagement and lower employee strains. Surface acting was uncorrelated with Turkish employees’ strain, though moderated regression analyses revealed interaction effects associated with national and individual level collectivism. These results suggest that collectivistic values may serve as a buffer against harmful effects associated with surface acting. This study is the first to directly compare emotional labour processes in U.S. and Turkish service employees and expand the process model of emotional labour to include collectivism. The theoretical implications of this expanded model are discussed, along with future research directions and practical applications of these findings.     

2008年美国金融危机中联储局的非传统应对措施

2008年美国遭遇自上世纪30年代经济大萧条以来最为严重的一次金融危机,姑且不论过去数年,联储局的货币政策或监管措施是否有瑕疵,在2008年危机日益恶化,眼见整个美国金融市场功能即将崩溃之际,联储局运用了传统功能以外的机制,发挥了一个中央银行面对瞬息变化的金融体系应有的弹性。联储局的权力虽然让它看起来像是宪法中规定美国政府三个部门外的＂第四个部门＂,但是2008年一连串的行动,确实也是度过此次危机的关键。这些行动纵然有美中不足之处,但达到了向银行与交易商提供资金以缓和＂去杠杆化＂过程的目的,并且改善信用市场的流动性以舒解融资渠道,扩充了商业融资渠道,防止金融机构资产负债的失衡。     

舌侧正畸牙齿移动的数值模拟

针对目前口腔舌侧正畸中,手术方案的制定以及牙齿移动的预测主要依靠医生经验,缺少定量的数据,可预期效 果差等缺点,提出了舌侧正畸牙齿移动数值计算模型,建立包括牙齿、牙周膜、皮质骨和松质骨的三维有限元模型,模拟 在不同的舌侧正畸力作用下,牙齿整体移动时牙周膜内表面的应变分布,并对牙周膜颈部和根尖部的应变加权值与现有 研究中牙齿移动量的实验数据进行拟合,通过颈部和根尖部的移动来确定牙齿整体的移动,在三维软件中实现对牙齿移 动的过程的模拟,得到移动后的模型作为下一个阶段计算的初始模型。实现了舌侧正畸牙齿移动的动态过程的模拟,该 数值模拟方法可以为舌侧正畸制定方案和预测效果提供参考。     

Job–Family Role Strain Among Low-Wage Workers

This exploratory study aimed to identify the personal, family, and job characteristics associated with low-wage employees job–family role strain. Data were collected from both English and non-English speaking workers at one hotel site. Multivariate data analyses revealed that different sets of circumstances create job–family strain for employees. Supervisor support was independently associated with two of the three job–family strain variables while other job factors emerged as significant when interacting with demographic variables. Findings suggest that structural factors associated with managing work and family responsibilities may more accurately measure job–family role strain for this worker population. The study provides further evidence that the concept of job–family role strain is inherently complex, warranting further investigation, especially for employees in low-wage earning jobs.     

基于光子晶体光纤的法布里-珀罗干涉传感器(英文)

光子晶体光纤作为新一代光纤和传统光纤相比具有许多独特的优点,因此研究基于光子晶体光纤的传感器已成为光纤传感技术领域的一个热点。该文在国际上首次报道了系列基于光子晶体光纤的法布里-珀罗干涉传感器,包括基于空芯光子晶体光纤的法布里-珀罗干涉应变、温度传感器;基于实心单模光子晶体光纤的法布里-珀罗干涉温度、折射率传感器;基于飞秒和157nm激光器微加工制作的实心光子晶体光纤法布里-珀罗干涉高温应变传感器。这些新型光子晶体光纤干涉传感器具有对温度不敏感、精度高、可靠性好、耐恶劣环境等突出优点,可望在能源、交通、航天航空、生化等领域得到重要应用。     

火焰拉伸率对层流燃烧速度的影响

将层流火焰消耗速度的概念与反应进程变量(progress variable)的定义相结合,给出了积分层流燃烧速度的广义定义.在准一维稳态系统中,分析了积分层流燃烧速度与未燃气体位移速度和已燃气体位移速度之间的关系.对甲烷空气和丙烷空气拉伸层流预混火焰在常温常压下进行了数值计算,研究不同当量比时,火焰拉伸率对层流燃烧速度的影响.通过火焰前锋放热率的积分层流燃烧速度和燃料消耗率的积分层流燃烧速度进行比较,结果表明,低拉伸火焰的马克斯坦数(Markstein number)与渐进分析一致,也与球形火焰获得的实验数据吻合.