2A). In all infected birds, histopathologic lesions were evident, although markedly different in samples collected at different times postinfection. At early stages (days 4 selleck chemicals llc to 8 p.i.), acute pancreatitis with necrotic acinar cells and massive inflammatory infiltration composed of macrophages, heterophils, lymphocytes, and plasma cells dominated over areas of healthy/uninvolved/spared tissue (Fig. 2B). From day 8 p.i., these necrotic inflammatory lesions/necrotic inflammatory areas were gradually replaced by ductule hyperplasia and lymphocytic infiltration with a mild degree of fibroplasia. At later stages (day 17 p.i), extensive fibrosis with lymphoid nodules replaced pancreatic parenchyma, and disruption of the normal architecture of the organ was evident (Fig. 2C).
Variable numbers of necrotic acinar cells were observed during the entire experimental period. Obstructive d
Clinical researchers regularly face the problem of a significant number of patients refusing to participate in a study or subsequently failing to return a questionnaire containing important information. In randomized clinical trials with a reasonable sample size, adequate blinding and concealment, and intention to treat analysis, these difficulties may limit the generalizability of findings. In observational research, however, if nonresponse is selective, ie, nonrespondents are not just a random sample of the sample, then estimates might be biased.1 The term ��nonrespondent bias�� (also referred to as volunteer bias, nonresponse bias [also used with different meanings], or nonparticipation bias) was first used in 1979 in a classic paper describing 9 potential biases of interest,2 and usage of this term has increased over time.
3 A clear divergence of nonrespondents from respondents is a necessary condition for nonrespondent bias.1 Given the high frequency and proportion of nonrespondents in studies, efforts have been made to find out if such divergences exist and, if so, whether they are associated with certain characteristics. Several demographic parameters have been thoroughly investigated.4�C8 However, data on personality characteristics that potentially influence nonrespondent bias are scarce. In this study, we examined 2 novel personality characteristics��avoidance coping and negative affectivity.
In avoidant coping, individuals react to a demanding situation by distraction or social diversion, Drug_discovery particularly if the situation constitutes a difficulty that must be solved.9 This strategy may be useful in moderation: gaining distance from an obstacle by participating in social activities may help in more easily finding a solution later on. However, extensive avoidance coping may result in unresolved situations. Highly avoidant patients might attempt to escape from anything suggestive of their illness and might thus be more prone to postpone completion of a questionnaire.