A comparison of two systems that code infant affective expression.

The Monadic Phases Coding System (MP) and the Maximally Discriminative Facial Movement Coding System (MAX) are both widely used to define and quantify categories of infant affective behavior. To evaluate the validity of extrapolating research findings from one system to another, we used both systems to code videotapes of 12 four-month-old infants engaged in mother–infant interaction. Interobserver agreement was higher with MP; interobserver reliability was equivalent. Point estimates for the percentages of negative and positive, but not interest, expressions were equivalent. MP and MAX generally agreed about the type of expression presented. Intersystem correlations supported the concurrent, but not discriminant, validity of MP and MAX categories. Interest expressions were not orthogonal to negative and positive affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New closed-form expressions for SNR estimates of Nakagami fading channels by the method of moments

Method of moments has been a parameter estimation technique appropriate to calculate signal-to-noise ratio (SNR) estimates in fading channel models in which an optimal technique like maximum likelihood estimation is not mathematically tractable. In this article, the ratio of the second moment squared to the fourth moment of the received signal envelope is considered to calculate an exact expression for the SNR estimate in Nakagami-m fading channel for M-QAM and \(\theta \)-MQAM modulations as well as expressions to evaluate the variance and the mean of the estimate. The paper presents two useful contributions for SNR estimation theory on Nakagami fading. Besides the exact algebraic expression for the estimate for a generalized QAM modulation scheme, its performance is evaluated through a statistical linearization argument.     

Antifeedant and toxic effects of sesquiterpenes fromSenecio palmensis to colorado potato beetle

A bioassay-guided fractionation of the aerial parts ofSenecio palmensis resulted in the isolation of two sesquiterpenes, 2,10-bisaboladien-1-one and 11-acetoxy-5-angeloyloxy-silphinen-3-one. The bisabolene and the silphinene represented 0.012% and 0.024% of the plant dry weight, respectively. Both compounds showed antifeedant activity againstLeptinotarsa decemlineata larvae and adults in short-term choice and no-choice bioassays. Both compounds were also tested against different species of phytopathogenic fungi. The beetles were more sensitive to these compounds in choice than in no-choice assays, with a gradient of increasing sensitivity from second instars to adults. Bisabolene was 45 times less active as an antifeedant than juglone, which was tested as a positive control. The silphinen was more active than the bisabolene, with a range of activity similar to juglone. Furthermore, exposure of fourth instars to these compounds over a 24-hr period resulted in reduced feeding and growth rates. To distinguish between antifeedant and toxic effects, growth efficiencies were calculated as the slope of the regression of relative growth rate on relative consumption rate. The comparison of these results with those of antifeedant simulation and contact toxicity bioassays indicates that feeding inhibition is the primary mode of action of the bisabolene, while the silphinene shows both antifeedant and toxic effects.     

Botulin toxins in the treatment of spasmodic torticollis

Hereditary nonpolyposis colorectal cancer (HNPCC) results from an inherited defect in one of the genes responsible for repair of errors that occur during DNA replication. Affected individuals have high risk for cancers of the colon and certain extracolonic sites. It appears that HNPCC patients form adenomas at about the same rate s the general population and there is some circumstantial evidence that adenoma is the precursor to colorectal carcinoma in the syndrome. It is hypothesized that HNPCC features accelerated progression from colonic adenoma to carcinoma, a process theoretically driven by the inability to repair DNA mismatches. Evidence in support of the "Aggressive Adenoma" in HNPCC is provided. We discuss our recommendations for colonoscopic surveillance on an annual basis for HNPCC gene-positive individuals, and for genetic counseling.     

Integrating a collaboration script and group awareness to support group regulation and emotions towards collaborative problem solving

International Journal of Computer-Supported Collaborative Learning - The research landscape displays increasing awareness of the important role of self-regulation and emotions in the process of...     

Removal of Direct Yellow 27 Dye by Ionic Flocculation: The Use of an Environmentally Friendly Surfactant

The presence of dyes is one of the main contributors to the organic load in textile effluents. In this study a mixture of surfactants, produced from animal/vegetable fats, was used to remove the Direct Yellow 27 dye from a synthetic wastewater through an ionic flocculation process. It was evaluated the effect of contact time, temperature, and surfactant concentration on dye removal efficiency. It was also evaluated the kinetics, equilibrium, and diffusion mechanism of the process. The kinetics of the process was well described by both Pseudo-second order and Elovich models. The transport of dye molecules to the surfactant flocs is controlled by the external layer. Equilibrium data showed a good fit to the Langmuir model. A removal rate of 93% was achieved in a single stage, after 5 h of contact time.     

A step-up/step-down direct current to direct current converter for high-power,high-current applications

This work proposes the conception of a nonisolated direct current (DC)-DC buck-boost converter employing the three-state switching cell. Similarly to interleaving, it is possible to achieve higher power levels than that regarding the classical buck-boost converter, but prominent advantages over the interleaved approach result, ie, the input current is continuous for duty ratios higher than 0.5; good current sharing is achieved without the need of special control schemes; and the active switches are connected to the same reference node as the input voltage source, as there is no need to use isolated drive circuitry. A thorough quantitative and qualitative analysis is carried for the entire range of the duty cycle D, considering that the proposed converter presents distinct behaviors for D < 0.5 and D > 0.5. An experimental prototype is developed and evaluated, while the results are discussed in detail.     

The impact of rapid release cycles on the integration delay of fixed issues

The release frequency of software projects has increased in recent years. Adopters of so-called rapid releases—short release cycles, often on the order of weeks, days, or even hours—claim that they can deliver fixed issues (i.e., implemented bug fixes and new features) to users more quickly. However, there is little empirical evidence to support these claims. In fact, our prior work shows that code integration phases may introduce delays for rapidly releasing projects—98% of the fixed issues in the rapidly releasing Firefox project had their integration delayed by at least one release. To better understand the impact that rapid release cycles have on the integration delay of fixed issues, we perform a comparative study of traditional and rapid release cycles. Our comparative study has two parts: (i) a quantitative empirical analysis of 72,114 issue reports from the Firefox project, and a (ii) qualitative study involving 37 participants, who are contributors of the Firefox, Eclipse, and ArgoUML projects. Our study is divided into quantitative and qualitative analyses. Quantitative analyses reveal that, surprisingly, fixed issues take a median of 54% (57 days) longer to be integrated in rapid Firefox releases than the traditional ones. To investigate the factors that are related to integration delay in traditional and rapid release cycles, we train regression models that model whether a fixed issue will have its integration delayed or not. Our explanatory models achieve good discrimination (ROC areas of 0.80–0.84) and calibration scores (Brier scores of 0.05–0.16) for rapid and traditional releases. Our explanatory models indicate that (i) traditional releases prioritize the integration of backlog issues, while (ii) rapid releases prioritize issues that were fixed in the current release cycle. Complementary qualitative analyses reveal that participants’ perception about integration delay is tightly related to activities that involve decision making, risk management, and team collaboration. Moreover, the allure of shipping fixed issues faster is a main motivator for adopting rapid release cycles among participants (although this motivation is not supported by our quantitative analysis). Furthermore, to explain why traditional releases deliver fixed issues more quickly, our participants point out the rush for integration in traditional releases and the increased time that is invested on polishing issues in rapid releases. Our results suggest that rapid release cycles may not be a silver bullet for the rapid delivery of new content to users. Instead, our results suggest that the benefits of rapid releases are increased software stability and user feedback.