We characterize here the MJ1541 gene product from Methanocaldococcus jannaschii, an enzyme that was annotated as a 5=-methylthioadenosine/S-adenosylhomocysteine deaminase (EC 3.5.4.31/3.5.4.28). The MJ1541 gene product catalyzes the conversion of 5=-deoxyadenosine to 5=-deoxyinosine as its major product but will also deaminate 5=-methylthioadenosine, S-adenosylhomocysteine, and adenosine to a small extent. On the basis of these findings, we are naming this new enzyme 5=-deoxyadenosine deaminase (DadD). The K m for 5=-deoxyadenosine was found to be 14.0 ؎ 1.2 M with a k cat /K m of 9.1 ؋ 10 9 M ؊1 s ؊1 . Radical S-adenosylmethionine (SAM) enzymes account for nearly 2% of the M. jannaschii genome, where the major SAM derived products is 5=-deoxyadenosine. Since 5=-dA has been demonstrated to be an inhibitor of radical SAM enzymes; a pathway for removing this product must be present. We propose here that DadD is involved in the recycling of 5=-deoxyadenosine, whereupon the 5=-deoxyribose moiety of 5=-deoxyinosine is further metabolized to deoxyhexoses used for the biosynthesis of aromatic amino acids in methanogens.

Putative mechanisms of action for the possible beneficial effects of yoga for PTSD-related symptomatology and clinical implications are discussed.

This study investigated how technology use impacts academic performance. A proposed model postulated that academic performance could be predicted by a cognitive independent variable-executive functioning problems-and an affective independent variable-technological anxiety or FOMO (fear of missing out)-mediated by how students choose to use technology. An unobtrusive smartphone application called "Instant Quantified Self" monitored daily smartphone unlocks and daily minutes of use. Other mediators included self-reported smartphone use, self-observed studying attention, self-reported multitasking preference, and a classroom digital metacognition tool that assessed the student's ability to understand the ramifications of technology use in the classroom that is not relevant to the learning process. Two hundred sixteen participants collected an average of 56 days of "Instant" application data, demonstrating that their smartphone was unlocked more than 60 times a day for three to four minutes each time for a total of 220 daily minutes of use. Results indicated that executive functioning problems predicted academic course performance mediated by studying attention and a single classroom digital metacognition subscale concerning availability of strategies of when to use mobile phones during lectures. FOMO predicted performance directly as well as mediated by a second classroom digital metacognition concerning attitudes toward mobile phone use during lectures. Implications for college students and professors include increasing metacognition about technology use in the classroom and taking "tech breaks" to reduce technology anxiety. El papel del funcionamiento ejecutivo y de la ansiedad tecnológica (FOMO) en el desempeño académico universitario mediatizado por la utilización de la tecnología y los hábitos multi-tarea R E S U M E N Este estudio analiza la repercusión del uso de la tecnología en el desempeño académico. Se propuso un modelo que postulaba que el desempeño académico podía predecirse mediante una variable independiente cognitiva (los problemas de funcionamiento ejecutivo) y una variable independiente afectiva (la ansiedad tecnológica o FOMO-el miedo a perderse algo), influido por el modo como los alumnos elegían utilizar la tecnología. Mediante una aplicación para móvil no intrusiva, denominada "Yo cuantificado instantáneo" seguía los desbloqueos diarios del móvil y los minutos de uso. Había otros mediadores, como el uso del móvil según el usuario, la atención en el estudio según la observa el usuario, preferencias de multi-tarea según el usuario y una nueva herramienta de medida digital en el aula para analizar la capacidad del alumno para entender las ramificaciones del uso de la tecnología en el aula que no es relevante para el proceso de aprendizaje. Un total de 216 participantes recogieron datos de la aplicación "instantánea" durante una media de 56 días, mostrando que su teléfono móvil era desbloqueado más de 60 veces al día entre tres y cuatro minutos cada vez durante un total de 220 minutos diarios de us...

Adolescent opioid misuse is a public health crisis, particularly among clinical populations of youth with substance misuse histories. Given the negative and often lethal consequences associated with opioid misuse among adolescents, it is essential to identify the risk and protective factors underlying early opioid misuse to inform targeted prevention efforts. Understanding the role of parental risk and protective factors is particularly paramount during the developmental stage of adolescence. Using a social-ecological framework, this study explored the associations between individual, peer, family, community, and school-level risk and protective factors and opioid use among adolescents with histories of substance use disorders (SUDs). Further, we explored the potential moderating role of poor parental monitoring in the associations between the aforementioned risk and protective factors and adolescent opioid use. Participants included 294 adolescents (Mage = 16 years; 45% female) who were recently discharged from substance use treatment, and their parents (n = 323). Results indicated that lifetime opioid use was significantly more likely among adolescents endorsing antisocial traits and those whose parents reported histories of substance abuse. Additionally, adolescents reporting more perceived availability of substances were significantly more likely to report lifetime opioid use compared to those reporting lower perceived availability of substances. Results did not indicate any significant moderation effects of parental monitoring on any associations between risk factors and lifetime opioid use. Findings generally did not support social-ecological indicators of opioid use in this high-risk population of adolescents, signaling that the social-ecological variables tested may not be salient risk factors among adolescents with SUD histories. We discuss these findings in terms of continuing care options for adolescents with SUD histories that target adolescents’ antisocial traits, perceived availability of substances, and parent histories of substance abuse, including practical implications for working with families of adolescents with SUD histories.

No abstract