The vegetative and reproductive (flowering) phases of Arabidopsis development are clearly separated. The onset of flowering is promoted by long photoperiods, but the constans (co) mutant flowers later than wild type under these conditions. The CO gene was isolated, and two zinc fingers that show a similar spacing of cysteines, but little direct homology, to members of the GATA1 family were identified in the amino acid sequence. co mutations were shown to affect amino acids that are conserved in both fingers. Some transgenic plants containing extra copies of CO flowered earlier than wild type, suggesting that CO activity is limiting on flowering time. Double mutants were constructed containing co and mutations affecting gibberellic acid responses, meristem identity, or phytochrome function, and their phenotypes suggested a model for the role of CO in promoting flowering.

Evidence-based health-care decision making requires comparisons of all relevant competing interventions. In the absence of randomized, controlled trials involving a direct comparison of all treatments of interest, indirect treatment comparisons and network meta-analysis provide useful evidence for judiciously selecting the best choice(s) of treatment. Mixed treatment comparisons, a special case of network meta-analysis, combine direct and indirect evidence for particular pairwise comparisons, thereby synthesizing a greater share of the available evidence than a traditional meta-analysis. This report from the ISPOR Indirect Treatment Comparisons Good Research Practices Task Force provides guidance on the interpretation of indirect treatment comparisons and network meta-analysis to assist policymakers and health-care professionals in using its findings for decision making. We start with an overview of how networks of randomized, controlled trials allow multiple treatment comparisons of competing interventions. Next, an introduction to the synthesis of the available evidence with a focus on terminology, assumptions, validity, and statistical methods is provided, followed by advice on critically reviewing and interpreting an indirect treatment comparison or network meta-analysis to inform decision making. We finish with a discussion of what to do if there are no direct or indirect treatment comparisons of randomized, controlled trials possible and a health-care decision still needs to be made.

The prevalence of incidentally detected pancreatic cysts on MR imaging is 13.5%, and increases with age. A majority of these cysts are not reported on MR imaging studies.

No abstract

Immune homeostasis in tissues is achieved through a delicate balance between pathogenic T cell responses directed at tissue-specific antigens and the ability of the tissue to inhibit these responses. The mechanisms by which tissues and the immune system communicate to establish and maintain immune homeostasis are currently unknown. Clinical evidence suggests that chronic or repeated exposure to self antigen within tissues leads to an attenuation of pathologic autoimmune responses, possibly as a means to mitigate inflammatory damage and preserve function. Many human organ-specific autoimmune diseases are characterized by the initial presentation of the disease being the most severe, with subsequent flares being of lesser severity and duration1. In fact, these diseases often spontaneously resolve, despite persistent tissue autoantigen expression2. In the practice of antigen-specific immunotherapy (antigen-SIT), allergens or self antigens are repeatedly injected in the skin, with a diminution of the inflammatory response occurring after each successive exposure3. Although these findings suggest that tissues acquire the ability to attenuate autoimmune reactions upon repeated responses to antigens, the mechanism by which this occurs is unknown. Here we show that upon expression of self antigen in a peripheral tissue, thymus-derived regulatory T cells (Treg cells) become activated, proliferate and differentiate into more potent suppressors, which mediate resolution of organ-specific autoimmunity. After resolution of the inflammatory response, activated Treg cells are maintained in the target tissue and are primed to attenuate subsequent autoimmune reactions when antigen is re-expressed. Thus, Treg cells function to confer ‘regulatory memory’ to the target tissue. These findings provide a framework for understanding how Treg cells respond when exposed to self antigen in peripheral tissues and offer mechanistic insight into how tissues regulate autoimmunity.

Context National public insurance for drugs is often based on evidence of comparative effectiveness and cost-effectiveness. This study describes how that evidence has been used across 3 jurisdictions (Australia, Canada, and Britain) that have been at the forefront of evidence-based coverage internationally.Objectives To describe how clinical and cost-effectiveness evidence is used in coverage decisions both within and across jurisdictions and to identify common issues in the process of evidence-based coverage.

Smoking places the patient at risk for increased time to union and complications. Previous smoking history also appears to increase the risk of osteomyelitis and increased time to union. The results highlight the need for orthopaedic surgeons to encourage their patients to enter a smoking cessation programs.

Purpose -This paper's aim is to examine the influence of perceived cost of sharing knowledge and affective trust in colleagues on the relationship between affective commitment and knowledge sharing.Design/methodology/approach -The methodology used was a survey of 496 employees from 15 organizations across ten industries.Findings -Affective trust in colleagues moderates the relationship between affective commitment and knowledge sharing and the relationship between cost of knowledge sharing and knowledge sharing.Research limitations/implications -Future researchers should operationalize the perceived cost of knowledge sharing construct to include other potential group barriers; for instance, politics and organizational barriers, management commitment and lack of trust.Practical implications -The findings of this study suggest that employees who value social relationships and social resources tend to view knowledge as a collectively owned commodity. As such, their knowledge sharing behavior reflects the model of reciprocal social exchanges.Social implications -The results of this study indicate that an organizational culture that encourages affect-based trust between colleagues will facilitate knowledge sharing.Originality/value -The paper bridges the gap between the literature on knowledge sharing, perceived cost of knowledge sharing, affective organizational commitment and trust in a single model.