Blackboard Rules for Coordinating Context-aware Applications in Mobile Ad Hoc Networks

Thanks to improvements in wireless communication technologies and increasing computing power in hand-held devices, mobile ad hoc networks are becoming an ever-more present reality. Coordination languages are expected to become important means in supporting this type of interaction. To this extent we argue the interest of the Bach coordination language as a middleware that can handle and react to context changes as well as cope with unpredictable physical interruptions that occur in opportunistic network connections. More concretely, our proposal is based on blackboard rules that model declaratively the actions to be taken once the blackboard content reaches a predefined state, but also that manage the engagement and disengagement of hosts and transient sharing of blackboards. The idea of reactiveness has already been introduced in previous work, but as will be appreciated by the reader, this article presents a new perspective, more focused on a declarative setting.Comment: In Proceedings FOCLASA 2012, arXiv:1208.432

Avoiding lodging in irrigated spring wheat. I. Stem and root structural requirements

A model of the lodging process has been successfully adapted for use on spring wheat grown in North-West Mexico (NWM). The lodging model was used to estimate the lodging-associated traits required to enable spring wheat grown in NWM with a typical yield of 6 t ha−1 and plant height of 0.7 m to achieve a lodging return period of 25 years. Target traits included a root plate spread of 51 mm and stem strength of the bottom internode of 268 N mm. These target traits increased to 54.5 mm and 325 N mm, respectively, for a crop yielding 10 t ha−1. Analysis of multiple genotypes across three growing seasons enabled relationships between both stem strength and root plate spread with structural dry matter to be quantified. A NWM lodging resistant ideotype yielding 6 t ha−1 would require 3.93 t ha−1 of structural stem biomass and 1.10 t ha−1 of root biomass in the top 10 cm of soil, which would result in a harvest index (HI) of 0.46 after accounting for chaff and leaf biomass. A crop yielding 10 t ha−1 would achieve a HI of 0.54 for 0.7 m tall plants or 0.41 for more typical 1.0 m tall plants. This study indicates that for plant breeders to achieve both high yields and lodging-proofness they must either breed for greater total biomass or develop high yielding germplasm from shorter crops

Inhibition Deficits Are Modulated by Age and CGG Repeat Length in Carriers of the \u3ci\u3eFMR1\u3c/i\u3e Premutation Allele Who Are Mothers of Children With Fragile X Syndrome

Individuals who carry a premutation (PM) allele on the FMR1 gene may experience executive limitations associated with their genetic status, including inhibition deficits. However, poor understanding of individualized risk factors has limited clinical management of this group, particularly in mothers who carry the PM allele who have children with fragile X syndrome (FXS). The present study examined CGG repeat length and age as factors that may account for variable expressivity of inhibition deficits. Participants were 134 carriers of the PM allele who were mothers of children with FXS. Inhibition skills were measured using both self-report and direct behavioral assessments. Increased vulnerability for inhibition deficits was observed at mid-range CGG lengths of approximately 80-100 repeats, with some evidence of a second zone of vulnerability occurring at approximately 130-140 CGG repeats. Risk associated with the genotype also became more pronounced with older age. This study identifies personalized risk factors that may be used to tailor the clinical management of executive deficits in carriers of the PM allele. Inhibition deficits may contribute to poor outcomes in carriers of the PM allele and their families, particularly in midlife and early old age, and clinical monitoring may be warranted

The 4-dimensional plant: effects of wind-induced canopy movement on light fluctuations and photosynthesis

Physical perturbation of a plant canopy brought about by wind is a ubiquitous phenomenon and yet its biological importance has often been overlooked. This is partly due to the complexity of the issue at hand: wind-induced movement (or mechanical excitation) is a stochastic process which is difficult to measure and quantify; plant motion is dependent upon canopy architectural features which, until recently, were difficult to accurately represent and model in 3-dimensions; light patterning throughout a canopy is difficult to compute at high-resolutions, especially when confounded by other environmental variables. Recent studies have reinforced the expectation that canopy architecture is a strong determinant of productivity and yield; however, links between the architectural properties of the plant and its mechanical properties, particularly its response to wind, are relatively unknown. As a result, biologically relevant data relating canopy architecture, light- dynamics, and short-scale photosynthetic responses in the canopy setting are scarce. Here, we hypothesize that wind-induced movement will have large consequences for the photosynthetic productivity of our crops due to its influence on light patterning. To address this issue, in this study we combined high resolution 3D reconstructions of a plant canopy with a simple representation of canopy perturbation as a result of wind using solid body rotation in order to explore the potential effects on light patterning, interception, and photosynthetic productivity. We looked at two different scenarios: firstly a constant distortion where a rice canopy was subject to a permanent distortion throughout the whole day; and secondly, a dynamic distortion, where the canopy was distorted in incremental steps between two extremes at set time points in the day. We find that mechanical canopy excitation substantially alters light dynamics; light distribution and modeled canopy carbon gain. We then discuss methods required for accurate modeling of mechanical canopy excitation (here coined the 4-dimensional plant) and some associated biological and applied implications of such techniques. We hypothesize that biomechanical plant properties are a specific adaptation to achieve wind-induced photosynthetic enhancement and we outline how traits facilitating canopy excitation could be used as a route for improving crop yield

The earth is flat (p < 0.05): significance thresholds and the crisis of unreplicable research

The widespread use of ‘statistical significance’ as a license for making a claim of a scientific finding leads to considerable distortion of the scientific process (according to the American Statistical Association). We review why degrading p -values into ‘significant’ and ‘nonsignificant’ contributes to making studies irreproducible, or to making them seem irreproducible. A major problem is that we tend to take small p -values at face value, but mistrust results with larger p -values. In either case, p -values tell little about reliability of research, because they are hardly replicable even if an alternative hypothesis is true. Also significance ( p ≤ 0.05) is hardly replicable: at a good statistical power of 80%, two studies will be ‘conflicting’, meaning that one is significant and the other is not, in one third of the cases if there is a true effect. A replication can therefore not be interpreted as having failed only because it is nonsignificant. Many apparent replication failures may thus reflect faulty judgment based on significance thresholds rather than a crisis of unreplicable research. Reliable conclusions on replicability and practical importance of a finding can only be drawn using cumulative evidence from multiple independent studies. However, applying significance thresholds makes cumulative knowledge unreliable. One reason is that with anything but ideal statistical power, significant effect sizes will be biased upwards. Interpreting inflated significant results while ignoring nonsignificant results will thus lead to wrong conclusions. But current incentives to hunt for significance lead to selective reporting and to publication bias against nonsignificant findings. Data dredging, p -hacking, and publication bias should be addressed by removing fixed significance thresholds. Consistent with the recommendations of the late Ronald Fisher, p -values should be interpreted as graded measures of the strength of evidence against the null hypothesis. Also larger p -values offer some evidence against the null hypothesis, and they cannot be interpreted as supporting the null hypothesis, falsely concluding that ‘there is no effect’. Information on possible true effect sizes that are compatible with the data must be obtained from the point estimate, e.g., from a sample average, and from the interval estimate, such as a confidence interval. We review how confusion about interpretation of larger p -values can be traced back to historical disputes among the founders of modern statistics. We further discuss potential arguments against removing significance thresholds, for example that decision rules should rather be more stringent, that sample sizes could decrease, or that p -values should better be completely abandoned. We conclude that whatever method of statistical inference we use, dichotomous threshold thinking must give way to non-automated informed judgment

Current and Past Immunodeficiency Are Associated with Higher Hospitalization Rates among Persons on Virologically Suppressive Antiretroviral Therapy for up to 11 Years

Background: Persons with human immunodeficiency virus (PWH) with persistently low CD4 counts despite efficacious antiretroviral therapy could have higher hospitalization risk. Methods: In 6 US and Canadian clinical cohorts, PWH with virologic suppression for ≥1 year in 2005-2015 were followed until virologic failure, loss to follow-up, death, or study end. Stratified by early (years 2-5) and long-term (years 6-11) suppression and lowest presuppression CD4 count 500 cells/μL had aIRRs of 1.44 during early suppression (95% confidence interval [CI], 1.01-2.06), and 1.67 (95% CI, 1.03-2.72) during long-term suppression. Among patients with lowest presuppression CD4 count ≥200 (56%), patients with current CD4 351-500 vs >500 cells/μL had an aIRR of 1.22 (95% CI,. 93-1.60) during early suppression and 2.09 (95% CI, 1.18-3.70) during long-term suppression. Conclusions: Virologically suppressed patients with lower CD4 counts experienced higher hospitalization rates and could potentially benefit from targeted clinical management strategies