Comparing two independent binomial proportions by a modified chi square test

When using the chi square test to compare the proportions of successes in two independent binomial samples, a new continuity correction is proposed, which equals half the size of the smaller sample. Exact computations of unconditional tail-probabilities, together with a theoretical argument, show that this correction is more appropriate than the YATES correction. This version of the chi square test is still conservative, but less so, and as a consequence more powerful, than the YATES corrected test.     

Environmental factors and host genetic variation shape the fungal endophyte communities within needles of Scots pine (Pinus sylvestris)

To determine the role of environmental and host genetic factors in shaping fungal endophyte communities we used culturing and metabarcoding techniques to quantify fungal taxa within healthy Scots pine (Pinus sylvestris) needles in a 7-y old provenance-progeny trial replicated at three sites. Both methods revealed a community of ascomycete and basidiomycete taxa dominated by the needle pathogen Lophodermium seditiosum. Differences in fungal endophyte taxon composition and diversity indices were highly significant among trial sites. Within two sites, fungal endophyte communities varied significantly among provenances. Furthermore, the communities differed significantly among maternal families within provenances in 11/15 and 7/15 comparisons involving culture and metabarcoding data respectively. We conclude that both environmental and host genetic variation shape the fungal endophyte community of P. sylvestris needles.     

Social facilitation of exploratory foraging behavior in capuchin monkeys (Cebus apella)

Much of the research on animal social learning focuses on complex cognitive functions such as imitation and emulation. When compelling evidence for such processes is not forthcoming, simpler processes are often assumed but rarely directly tested for. In this study we address the phenomenon of social facilitation, whereby the presence of a feeding conspecific is hypothesized to affect the motivation and behavior of the subject, elevating the likelihood of exploration and discovery in relation to the task at hand. Using a novel foraging task, sufficiently challenging that only just over half the subjects successfully gained food from it, we compared the performance of capuchin monkeys working either alone, or in a “social” condition where an actively feeding conspecific was in an adjacent chamber. Although similar numbers of subjects in these conditions were eventually successful during the 20 trials presented, the latency to successful solution of the task was over three times faster for monkeys in the social condition. The minority of monkeys that failed to learn (9/23) were then exposed to a proficient model. Only those older than 5 years provided evidence of learning from this. Accordingly, we obtained evidence for the social facilitation the study was designed to test for, and limited supplementary evidence for social learning in the older individuals who had not learned individually. These results are discussed in relation to other recent evidence for social learning in monkeys. Am. J. Primatol. 71:419–426, 2009. © 2009 Wiley‐Liss, Inc.     

Automated Insulin Delivery Systems as a Treatment for Type 2 Diabetes Mellitus: A Review

ObjectiveApproximately 6.3% of the worldwide population has type 2 diabetes mellitus (T2DM), and the number of people requiring insulin is increasing. Automated insulin delivery (AID) systems integrate continuous subcutaneous insulin infusion and continuous glucose monitoring with a predictive control algorithm to provide more physiologic glycemic control. Personalized glycemic targets are recommended in T2DM owing to the heterogeneity of the disease. Based on the success of hybrid closed-loop systems in improving glycemic control and safety in type 1 diabetes mellitus, there has been further interest in the use of these systems in people with T2DM.MethodsWe performed a review of AID systems with a focus on the T2DM population.ResultsIn 5 randomized controlled trials, AID systems improve time in range and reduce glycemic variability, without increasing insulin requirements or the risk of hypoglycemia.ConclusionAID systems in T2DM are safe and effective in hospitalized and closely monitored settings. Home studies of longer duration are required to assess for long-term benefit and identify target populations of benefit.     

Lipoprotein(a) and Atherosclerotic Cardiovascular Disease,the Impact of Available Lipid-Lowering Medications on Lipoprotein(a): An Update on New Therapies

ObjectiveTo review evidence of existing and new pharmacological therapies for lowering lipoprotein(a) (Lp[a]) concentrations and their impact on clinically relevant outcomes.MethodsWe searched for literature pertaining to Lp(a) and pharmacological treatments in PubMed. We reviewed articles published between 1963 and 2020.ResultsWe found that statins significantly increased Lp(a) concentrations. Therapies that demonstrated varying degrees of Lp(a) reduction included ezetimibe, niacin, proprotein convertase subtilisin/kexin type 9 inhibitors, lipoprotein apheresis, fibrates, aspirin, hormone replacement therapy, antisense oligonucleotide therapy, and small interfering RNA therapy. There was limited data from large observational studies and post hoc analyses showing the potential benefits of these therapies in improving cardiovascular outcomes.ConclusionThere are multiple lipid-lowering agents currently being used to treat hyperlipidemia that also have a Lp(a)-lowering effect. Two RNA therapies specifically targeted to lower Lp(a) are being investigated in phase 3 clinical trials and, thus far, have shown promising results. However, evidence is lacking to determine the clinical relevance of reducing Lp(a). At present, there is a need for large-scale, randomized, controlled trials to evaluate cardiovascular outcomes associated with lowering Lp(a).