Acoustic Beam Characterization and Selection for Optimized Underwater Communication

To increase underwater acoustic signal detectability and conserve energy, nodes leverage directional transmissions. In addition, nodes operate in a three-dimensional (3D) environment that is categorized as inhomogeneous where a propagating signal changes its direction based on the observed sound speed profile (SSP). Coupling 3D directional transmission with frequent node drifts and the varying underwater SSP complicates the process of selecting suitable transmission angles to maintain underwater communication links. Fundamentally, utilizing directional transmission while nodes are drifting causes breaks in established communication links and thus nodes need to find new angles to reestablish these links. Moreover, selecting arbitrary transmission angles may lead to overlapping beams or result in leaving an underwater region uncovered. To tackle the abovementioned challenges, this paper proposes an autonomous beam selection approach that optimizes underwater communication by selecting non-overlapping beams while mitigating the possibility of missing a region, i.e., maximize coverage. Such optimization is achieved by utilizing a structured angle selection mechanism that accounts for the capability of the used transducer. Moreover, we introduce an algorithm suited for resource constrained nodes to classify rays into different types. Then we divide the underwater medium into regions where each region is identified by the limits of the coverage area of each ray type. Finally, we utilize the limits of these regions to aid nodes in selecting the best ray to reestablish communication with drifted nodes. We validate our contribution through simulation where actual SSPs are leveraged to validate the beam classification process.

Textile Concentric Ring Electrodes: Influence of Position and Electrode Size on Cardiac Activity Monitoring

Continuous ECG monitoring can play an important role in the rapid detection of pathological signatures and arrhythmias. Current systems use electrodes with limitations in wearable long-term applications and spatial selectivity. In this work, two sizes of textile concentric ring electrodes (TCRE42 and TCRE50) were developed and tested for monitoring cardiac activity. The low-cost devices were found to be easy to implement and to potentially have the advantages of textile electrodes for being lightweight, stretchable, adjustable, washable, and long-lasting. Both TCREs yielded similar signal detectability of different ECG waves. The optimal P wave recording area (OPA) for detecting signals was on the upper right chest. Although the absolute signal amplitude of TCRE records was smaller than that of lead II, normalized amplitude in the OPA is similar for T wave and higher for P wave. The TCREs also allowed better analysis of P wave morphology and were able to detect more right and left atrial depolarization waves. TCRE48 showed slightly better detectability, normalized amplitude, and spatial selectivity than TCRE50 within the OPA. The authors consider the TCRE suitable for use in ubiquitous mobile health care systems, especially for atrial activity monitoring and diagnosis.

Choice of choice models: Theory of signal detectability outperforms Bradley-Terry-Luce choice model

Identifying the best framework for two-choice decision-making has been a goal of psychology theory for many decades (Bohil, Szalma, & Hancock, 2015; Macmillan & Creelman, 1991). There are two main candidates: the theory of signal detectability (TSD) (Swets, Tanner Jr, & Birdsall, 1961; Thurstone, 1927) based on a normal distribution/probit function, and the choice-model theory (Link, 1975; Luce, 1959) that uses the logistic distribution/logit function. A probit link function, and hence TSD, was shown to have a better Bayesian Goodness of Fit than the logit function for every one of eighteen diverse psychology data sets (Open-Science-Collaboration, 2015a), conclusions having been obtained using Generalized Linear Mixed Models (Lindstrom & Bates, 1990; Nelder & Wedderburn, 1972) . These findings are important, not only for the psychology of perceptual, cognitive and social decision-making, but for any science that use binary proportions to measure effectiveness, as well as the meta-analysis of such studies.

Choice of choice models: Theory of signal detectability outperforms Bradley-Terry-Luce choice model

Identifying the best framework for two-choice decision-making has been a goal of psychology theory for many decades (Bohil, Szalma, & Hancock, 2015; Macmillan & Creelman, 1991). There are two main candidates: the theory of signal detectability (TSD) (Swets, Tanner Jr, & Birdsall, 1961; Thurstone, 1927) based on a normal distribution/probit function, and the choice-model theory (Link, 1975; Luce, 1959) that uses the logistic distribution/logit function. A probit link function, and hence TSD, was shown to have a better Bayesian Goodness of Fit than the logit function for every one of eighteen diverse psychology data sets (Open-Science-Collaboration, 2015a), conclusions having been obtained using Generalized Linear Mixed Models (Lindstrom & Bates, 1990; Nelder & Wedderburn, 1972) . These findings are important, not only for the psychology of perceptual, cognitive and social decision-making, but for any science that use binary proportions to measure effectiveness, as well as the meta-analysis of such studies.

Comparison of Neuropsychological Functioning Between Adults With Early- and Late-Onset DSM-5 ADHD

Objective: We aimed to compare the visually dependent neuropsychological functioning among adults with Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) ADHD who recalled symptom onset by and after age 7 and non-ADHD controls. Method: We divided the participants, aged 17 to 40 years, into three groups—(a) ADHD, onset <7 years (early-onset, n = 142); (b) ADHD, onset between 7 and <12 years (late-onset, n = 41); (c) non-ADHD controls ( n = 148)—and compared their neuropsychological functioning, measured by the Cambridge Neuropsychological Testing Automated Battery. Results: Both ADHD groups had deficits in attention and signal detectability, spatial working memory, and short-term spatial memory, but only the early-onset group showed deficits in alertness, set-shifting, and planning after controlling for age, sex, and psychiatric comorbidities. There was no statistical difference between the two ADHD groups in neuropsychological functioning. Conclusion: DSM-5 criteria for diagnosing adult ADHD are not too lax regarding neuropsychological functioning.

The Effect of Citicoline Supplementation on Motor Speed and Attention in Adolescent Males

Objective: This study assessed the effects of citicoline, a nutraceutical, on attention, psychomotor function, and impulsivity in healthy adolescent males. Method: Seventy-five healthy adolescent males were randomly assigned to either the citicoline group ( n = 51 with 250 or 500 mg citicoline) or placebo ( n = 24). Participants completed the Ruff 2&7 Selective Attention Test, Finger Tap Test, and the Computerized Performance Test, Second Edition (CPT-II) at baseline and after 28 days of supplementation. Results: Individuals receiving citicoline exhibited improved attention ( p = 0.02) and increased psychomotor speed ( p = 0.03) compared with those receiving placebo. Higher weight-adjusted dose significantly predicted increased accuracy on an attention task ( p = 0.01), improved signal detectability on a computerized attention task ( p = 0.03), and decreased impulsivity ( p = 0.01). Discussion: Adolescent males receiving 28 days of Cognizin® citicoline showed improved attention and psychomotor speed and reduced impulsivity compared to adolescent males who received placebo.