Coliphage Field Kit : technical final report

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Group decision-making is optimal in adolescence

Abstract Group decision-making is required in early life in educational settings and central to a well-functioning society. However, there is little research on group decision-making in adolescence, despite the significant neuro-cognitive changes during this period. Researchers have studied adolescent decision-making in ‘static’ social contexts, such as risk-taking in the presence of peers, and largely deemed adolescent decision-making ‘sub-optimal’. It is not clear whether these findings generalise to more dynamic social contexts, such as the discussions required to reach a group decision. Here we test the optimality of group decision-making at different stages of adolescence. Pairs of male pre-to-early adolescents (8 to 13 years of age) and mid-to-late adolescents (14 to 17 years of age) together performed a low-level, perceptual decision-making task. Whenever their individual decisions differed, they were required to negotiate a joint decision. While there were developmental differences in individual performance, the joint performance of both adolescent groups was at adult levels (data obtained from a previous study). Both adolescent groups achieved a level of joint performance expected under optimal integration of their individual information into a joint decision. Young adolescents’ joint, but not individual, performance deteriorated over time. The results are consistent with recent findings attesting to the competencies, rather than the shortcomings, of adolescent social behaviour

Systematic re-evaluation of intraoperative motor-evoked potential suppression in scoliosis surgery

10.1186/s13013-018-0161-3Scoliosis and Spinal Disorders1311

Confidence matching in group decision-making

Most important decisions in our society are made by groups, from cabinets and commissions to boards and juries. When disagreement arises, opinions expressed with higher confidence tend to carry more weight1,2 . Although an individual’s degree of confidence often reflects the probability that their opinion is correct3,4, it can also vary with task-irrelevant psychological, social, cultural and demographic factors5–9. Therefore, to combine their opinions optimally, group members must adapt to each other’s individual biases and express their confidence according to a common metric10–12. However, solving this communication problem is computationally difficult. Here we show that pairs of individuals making group decisions meet this challenge by using a heuristic strategy that we call ‘confidence matching’: they match their communicated confidence so that certainty and uncertainty is stated in approximately equal measure by each party. Combining the behavioural data with computational modelling, we show that this strategy is effective when group members have similar levels of expertise, and that it is robust when group members have no insight into their relative levels of expertise. Confidence matching is, however, sub-optimal and can cause miscommunication about who is more likely to be correct. This herding behaviour is one reason why groups can fail to make good decisions10–12

3T3-L1 adipocytes induce dysfunction of MIN6 insulin-secreting cells via multiple pathways mediated by secretory factors in a co-culture system

Abstract Pancreatic b-cell dysfunction is an important pathological change in type 2 diabetes, which is tightly related to obesity. However, the direct role of adipose tissue in b-cell dysfunction has not been well understood. In this study, we examined the effects of 3T3-L1 adipocytes on MIN6 insulin-secreting cells in a co-culture system. MIN6 cells used here kept most of b-cell functions but less sensitive to glucose stimulation. Tolbutamide, the KATP channel blocker, was therefore used to stimulate insulin secretion in this report. MIN6 cells co-cultured with 3T3-L1 adipocytes had significantly reduced intracellular calcium concentration ([Ca2+]i) and lost the ability to secrete insulin in response to tolbutamide, compared to the control cells. 3T3-L1 adipocytes significantly decreased the expression of insulin, glucokinase and Kir6.2 genes but increased the expression of uncoupling protein-2 (UCP-2) in MIN6 cells after one week of co-culture, as measured by semi-quantitative RT-PCR. 3T3-L1 adipocyte-conditioned medium also significantly decreased insulin secretion and the expression of insulin, glucokinase and Kir6.2 genes in MIN6 cells. The conditioned medium also reduced tyrosine kinase activity in MIN6 cells. The inhibitor of protein tyrosine kinase, genistein, decreased the expression of glucokinase and Kir6.2 in MIN6 cells, while two free fatty acids, oleic acid and linoleic acids, were found to increase UCP-2 expression. The present study demonstrates that 3T3-L1 adipocytes directly impair insulin secretion and the expression of important genes in MIN6 cells. The effects of 3T3-L1 adipocytes on MIN6 cells are ascribed to secreted bioactive factors and may be mediated via multiple pathways, which include the upregulation of UCP-2 expression via free fatty acids, and downregulation of glucokinase and Kir6.2 expression via decreasing protein tyrosine kinase activity