Evaluating The Effectiveness Of An Anti-Texting-While-Driving Training Program For Young Drivers: The Role Of Adhd Symptomatology

A long-standing challenge for public health and safety is that motor vehicle crashes (MVCs) are the leading cause of death for U.S. teenagers, a population with disproportionately high crash involvement relative to other road users. Quantitative and qualitative research has identified distracted driving as a significant contributor to young drivers’ overrepresentation in MVCs. This study was designed in the context of this notable public health concern, and the primary goal was to examine psychological factors that are hypothesized, via the Theory of Planned Behavior, to underlie teenage drivers’ decisions to text-while-driving (TWD) with a focus on the influence of ADHD symptoms. The psychological factors of interest were attitudes toward TWD, perceptions of crash risk while TWD, self-perceptions of competence as a driver, and perceptions of task performance. The aims of this project were addressed through a program evaluation of an experiential driver training program designed to educate young novice drivers on the dangers associated with TWD. This program, Turn Off Texting (TOT), was designed and run by the Youth Safety Council of Vermont and the Vermont Department of Motor Vehicles, Safety and Education Unit. Participants included 1203 high school teenagers who participated in 42 TOT program demonstrations across Vermont. The first aim of this study was to examine the influence of ADHD symptoms on psychological factors and behavioral intentions while controlling for and examining the effects of age, gender, and driving experience. ADHD symptoms were associated with more favorable attitudes toward TWD, greater intentions to TWD in the future, and lesser intentions to intervene on a distracted driver in the future. Male gender and increased driving experience also tended to be associated with riskier attitudes, perceptions, and intentions. The second aim of this work was to examine if the psychological factors mediate the associations between ADHD symptoms and the two behavioral intention variables. Results from multiple mediation models showed that only attitudes toward TWD mediated the relations for both intentions to TWD and to intervene in the future. ADHD symptoms continued to have a direct effect on behavioral intentions even when accounting for the indirect effects of the psychological factors; these findings suggest a direct relation of ADHD symptoms and an indirect relation via attitudes. The third and final aim of this study was to investigate the influence of ADHD symptoms, as well as age, gender, and driving experience, on the rate of change in the psychological factors and behavioral intention variables over the course of the TOT program. Findings from two-level regression models showed that the TOT program generally was effective in its goal to produce safer views in regards to the psychological factors and intended behaviors. As hypothesized, ADHD symptoms were associated with less change toward safer attitudes, perceptions of crash risk, and both intentions to TWD and intentions to intervene in the future; the influences of male gender and increased driving experience were similar in their associations with less change toward safer attitudes, perceptions, and intentions. The findings from this study’s three aims have important implications for the development and continued evaluation of specialized driver training programs. Namely, attitudes toward TWD are a viable target for intervention given this factor’s direct and indirect (in the association of ADHD symptoms) effect on intended behavior. Increasing ADHD symptoms and male gender were associated with less change over the course of the program, which represent two areas for more specialized intervention and study

Low-energy structures of zinc borohydride Zn(BH4_4)2_2

We present a systematic study of the low-energy structures of zinc borohydride, a crystalline material proposed for the hydrogen storage purpose. In addition to the previously proposed structures, many new low-energy structures of zinc borohydride are found by utilizing the minima-hopping method. We identify a new dynamically stable structure which belongs to the $I4_122$ space group as the most stable phase of zinc borohydride at low temperatures. A low transition barrier between $I4_122$ and $P1$, the two lowest-lying phases of zinc borohydride is predicted, implying that a coexistence of low-lying phases of zinc borohydride is possible at ambient conditions. An analysis based on the simulated X-ray diffraction pattern reveals that the $I4_122$ structure exhibits the same major features as the experimentally synthesized zinc borohydride samples.Comment: Version accepted by Phys. Rev. B. Manuscript has 8 pages, 5 figures, 2 tables (with 6 pages, 5 figures, 2 tables in supplemental material

Coding for Racetrack Memories

Racetrack memory is a new technology which utilizes magnetic domains along a nanoscopic wire in order to obtain extremely high storage density. In racetrack memory, each magnetic domain can store a single bit of information, which can be sensed by a reading port (head). The memory has a tape-like structure which supports a shift operation that moves the domains to be read sequentially by the head. In order to increase the memory's speed, prior work studied how to minimize the latency of the shift operation, while the no less important reliability of this operation has received only a little attention. In this work we design codes which combat shift errors in racetrack memory, called position errors. Namely, shifting the domains is not an error-free operation and the domains may be over-shifted or are not shifted, which can be modeled as deletions and sticky insertions. While it is possible to use conventional deletion and insertion-correcting codes, we tackle this problem with the special structure of racetrack memory, where the domains can be read by multiple heads. Each head outputs a noisy version of the stored data and the multiple outputs are combined in order to reconstruct the data. Under this paradigm, we will show that it is possible to correct, with at most a single bit of redundancy, $d$ deletions with $d+1$ heads if the heads are well-separated. Similar results are provided for burst of deletions, sticky insertions and combinations of both deletions and sticky insertions

Deep learning applied to computational mechanics: A comprehensive review, state of the art, and the classics

Three recent breakthroughs due to AI in arts and science serve as motivation: An award winning digital image, protein folding, fast matrix multiplication. Many recent developments in artificial neural networks, particularly deep learning (DL), applied and relevant to computational mechanics (solid, fluids, finite-element technology) are reviewed in detail. Both hybrid and pure machine learning (ML) methods are discussed. Hybrid methods combine traditional PDE discretizations with ML methods either (1) to help model complex nonlinear constitutive relations, (2) to nonlinearly reduce the model order for efficient simulation (turbulence), or (3) to accelerate the simulation by predicting certain components in the traditional integration methods. Here, methods (1) and (2) relied on Long-Short-Term Memory (LSTM) architecture, with method (3) relying on convolutional neural networks. Pure ML methods to solve (nonlinear) PDEs are represented by Physics-Informed Neural network (PINN) methods, which could be combined with attention mechanism to address discontinuous solutions. Both LSTM and attention architectures, together with modern and generalized classic optimizers to include stochasticity for DL networks, are extensively reviewed. Kernel machines, including Gaussian processes, are provided to sufficient depth for more advanced works such as shallow networks with infinite width. Not only addressing experts, readers are assumed familiar with computational mechanics, but not with DL, whose concepts and applications are built up from the basics, aiming at bringing first-time learners quickly to the forefront of research. History and limitations of AI are recounted and discussed, with particular attention at pointing out misstatements or misconceptions of the classics, even in well-known references. Positioning and pointing control of a large-deformable beam is given as an example.Comment: 275 pages, 158 figures. Appeared online on 2023.03.01 at CMES-Computer Modeling in Engineering & Science

Stem cells and fluid flow drive cyst formation in an invertebrate excretory organ.

Cystic kidney diseases (CKDs) affect millions of people worldwide. The defining pathological features are fluid-filled cysts developing from nephric tubules due to defective flow sensing, cell proliferation and differentiation. The underlying molecular mechanisms, however, remain poorly understood, and the derived excretory systems of established invertebrate models (Caenorhabditis elegans and Drosophila melanogaster) are unsuitable to model CKDs. Systematic structure/function comparisons revealed that the combination of ultrafiltration and flow-associated filtrate modification that is central to CKD etiology is remarkably conserved between the planarian excretory system and the vertebrate nephron. Consistently, both RNA-mediated genetic interference (RNAi) of planarian orthologues of human CKD genes and inhibition of tubule flow led to tubular cystogenesis that share many features with vertebrate CKDs, suggesting deep mechanistic conservation. Our results demonstrate a common evolutionary origin of animal excretory systems and establish planarians as a novel and experimentally accessible invertebrate model for the study of human kidney pathologies

The ATF3 Transcription Factor Is a Short-Lived Substrate of the Arg/N-Degron Pathway

The Arg/N-degron pathway targets proteins for degradation by recognizing their specific N-terminal residues or, alternatively, their non-N-terminal degrons. In mammals, this pathway is mediated by the UBR1, UBR2, UBR4, and UBR5 E3 ubiquitin ligases, and by the p62 regulator of autophagy. UBR1 and UBR2 are sequelogous, functionally overlapping, and dominate the targeting of Arg/N-degron substrates in examined cell lines. We constructed, here, mouse strains in which the double mutant [UBR1^(–/–)UBR2^(–/–)] genotype can be induced conditionally, in adult mice. We also constructed human [UBR1^(–/–)UBR2^(–/–)] HEK293T cell lines that unconditionally lack UBR1/UBR2. ATF3 is a basic leucine zipper transcription factor that regulates hundreds of genes and can act as either a repressor or an activator of transcription. Using the above double-mutant mice and human cells, we found that the levels of endogenous, untagged ATF3 were significantly higher in both of these [UBR1^(–/–)UBR2^(–/–)] settings than in wild-type cells. We also show, through chase-degradation assays with [UBR1^(–/–)UBR2^(–/–)] and wild-type human cells, that the Arg/N-degron pathway mediates a large fraction of ATF3 degradation. Furthermore, we used split-ubiquitin and another protein interaction assay to detect the binding of ATF3 to both UBR1 and UBR2, in agreement with the UBR1/UBR2-mediated degradation of endogenous ATF3. Full-length 24 kDa ATF3 binds to ∼100 kDa fragments of 200 kDa UBR1 and UBR2 but does not bind (in the setting of interaction assays) to full-length UBR1/UBR2. These and other binding patterns, whose mechanics remain to be understood, may signify a conditional (regulated) degradation of ATF3 by the Arg/N-degron pathway

Formyl-methionine as a degradation signal at the N-termini of bacterial proteins

In bacteria, all nascent proteins bear the pretranslationally formed N-terminal formyl-methionine (fMet) residue. The fMet residue is cotranslationally deformylated by a ribosome-associated deformylase. The formylation of N-terminal Met in bacterial proteins is not strictly essential for either translation or cell viability. Moreover, protein synthesis by the cytosolic ribosomes of eukaryotes does not involve the formylation of N-terminal Met. What, then, is the main biological function of this metabolically costly, transient, and not strictly essential modification of N‑terminal Met, and why has Met formylation not been eliminated during bacterial evolution? One possibility is that the similarity of the formyl and acetyl groups, their identical locations in N‑terminally formylated (Nt‑formylated) and Nt-acetylated proteins, and the recently discovered proteolytic function of Nt-acetylation in eukaryotes might also signify a proteolytic role of Nt‑formylation in bacteria. We addressed this hypothesis about fMet‑based degradation signals, termed fMet/N-degrons, using specific E. coli mutants, pulse-chase degradation assays, and protein reporters whose deformylation was altered, through site-directed mutagenesis, to be either rapid or relatively slow. Our findings strongly suggest that the formylated N-terminal fMet can act as a degradation signal, largely a cotranslational one. One likely function of fMet/N-degrons is the control of protein quality. In bacteria, the rate of polypeptide chain elongation is nearly an order of magnitude higher than in eukaryotes. We suggest that the faster emergence of nascent proteins from bacterial ribosomes is one mechanistic and evolutionary reason for the pretranslational design of bacterial fMet/N‑degrons, in contrast to the cotranslational design of analogous Ac/N‑degrons in eukaryotes