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INTRODUCTION: Tobacco companies have devoted increased resources in recent years to developing and marketing heated tobacco products (HTPs) as alternatives to combustible products like cigarettes. However, little is known about correlates of awareness and use of these products in American young adults. METHODS: Two thousand four hundred ninety-seven young adults (mean age = 21.6) completed survey items on HTP awareness and lifetime use in 2018-2019. Logistic regression models compared young adults who were (1) unaware of HTPs (reference group) with those who were, (2) aware of HTPs, and (3) had ever used HTPs on demographic, tobacco, and other substance use characteristics. Among current smokers, these groups were compared on cigarette use, dependence, and readiness to quit. RESULTS: Approximately 12% of respondents (n = 293) were aware of HTPs, and 5% (n = 134) reported lifetime HTP use. Controlling for demographics, HTP awareness and use were both associated with greater use of all types of tobacco products, number of different tobacco products, and use of marijuana and other drugs. Among current smokers, HTP awareness and use correlated with heavier cigarette consumption, greater dependence, and past-month marijuana use, but not with recent quit attempts or thinking about quitting cigarettes. CONCLUSIONS: Awareness and use of HTPs among young adults were associated with greater use of tobacco products and other substances and, among current smokers, with greater cigarette dependence (but not cessation-related factors). As these products become increasingly available in the United States, additional surveillance and monitoring activities are needed to better understand use patterns, consequences, and reasons for using HTPs. IMPLICATIONS: Few studies have examined factors associated with awareness and use of heated tobacco products (HTPs) among US young adults. HTP awareness and lifetime use correlated with a range of factors, including male gender, white race/ethnicity, and tobacco and other substance use. Lifetime use of HTPs was low (5%); most lifetime HTP users reported history of other tobacco use, but a sizeable minority (14%) reported no other tobacco product use history. Among current cigarette smokers, cigarette dependence, poly-tobacco use, and marijuana use-but not cigarette cessation attempts or contemplation-were associated with greater likelihood of awareness and use of HTPs.

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BACKGROUND: Longitudinal studies report associations between use of electronic cigarettes (ECs) and cigarettes over time among young people, but do not distinguish within- from between-person effects, which complicates interpretation of findings. Further, the role of shared risk factors, such as substance use and mental health, in explaining longitudinal associations between EC and cigarette use remains unclear. This study used within- and between-person analyses to assess longitudinal associations between youths' EC and cigarette use and shared risk factors. METHODS: Between 2015 and 2017, 2039 youths completed three Web-based surveys, allowing us to model EC and cigarette use from ages 16 to 20. Auto-regressive latent growth models with structured residuals (ALT-SR) examined both between-person and within-person associations between past-month frequency of EC use, cigarette use, and third variables (alcohol and marijuana use, mental health symptoms) over time. RESULTS: Models revealed robust reciprocal associations between EC and cigarette use, such that more frequent EC use at one time predicted more frequent cigarette use at the subsequent time, and vice versa. Between-person analyses showed associations between shared risk factors and both EC and cigarette use. However, shared risk factors did not predict frequency of subsequent EC and cigarette use in within-person analyses. CONCLUSIONS: Findings add to a growing body of research suggesting that EC use among youth is prospectively associated with progression toward greater cigarette use. Shared risk factors may help explain differences in EC and cigarette use patterns between young people, but do not appear to influence longitudinal trajectories of EC and cigarette use within individuals. IMPLICATIONS: This study examined within- and between-person associations between e-cigarette use, cigarette use, and shared risk factors (alcohol use, marijuana use, mental health symptoms) in a longitudinal cohort of youths. Within- and between-person analyses revealed reciprocal prospective associations between e-cigarette and cigarette use, suggesting a progression toward more frequent use of both products over time. The shared risk factors examined here did not affect escalations in e-cigarette or cigarette use over time within individuals, but likely influence which youths use these products. Findings add to a growing body of evidence suggesting that e-cigarette use increases subsequent cigarette use in young people.

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Muchos instrumentos se crean con el propósito principal de evaluar sujetos con relación a un solo rasgo. Sin embargo, los rasgos psicológicos son frecuentemente complejos y contienen manifestaciones de dominio específico. Como tal, muchos instrumentos brindan información que son consistentes tanto con las estructuras unidimensionales como las multidimensionales. Por desgracia, muchas veces, los investigadores aplicados hacen determinaciones sobre la estructura final basado únicamente en los índices de ajuste obtenidos a partir de modelos de ecuaciones estructurales. Dado que los índices de ajuste generalmente favorecen al modelo bifactor sobre los modelos de medición competidores, es imperativo que los investigadores hacen uso de la información disponible que los modelos bifactor tienen para ofrecer con el fin de calcular los índices informativos incluyendo coeficientes de confiabilidad omega, confiabilidad del constructo, varianza común explicada, y el porcentaje de correlaciones no contaminadas. Dichos índices proporcionan información acerca de la fuerza tanto de los factores generales como de los factores específicos con el fin de sacar conclusiones acerca de la dimensionalidad y la puntuación global de las escalas (y subescalas). En este documento, se describen estos índices y ofrecen un nuevo módulo que facilita su cálculo.

Many instruments are created with the primary purpose of scaling individuals on a single trait. However psychological traits are often complex and contain domain specific manifestations. As such, many instruments produce data that are consistent with both unidimensional and multidimensional structures. Unfortunately, oftentimes, applied researchers make determinations about the final structure based solely on fit indices obtained from structural equation models. Given that fit indices generally favor the bifactor model over comping measurement models it is imperative that researchers make use of the available information the bifactor has to offer in order to compute informative indices including omega reliability coefficients, construct reliability, explained common variance, and percentage of uncontaminated correlations. Said indices provide unique information about the strength of both the general and specific factors in order to draw conclusions about dimensionality and overall scoring of scales (and subscales). Herein, we describe these indices and offer a new module which easily facilitates their computation.

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Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation or both. Here, we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming.

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PURPOSE: To determine the feasibility of the surgical procedure and to collect some safety data regarding the bioelectronics of a novel micro drug pump for intravitreal drug delivery in a Beagle dog model for up to 1 year. METHODS: Thirteen Beagle dogs were assigned to two groups. The experimental group (n = 11) underwent pars plana implantation of MicroPump; the body of which was sutured episclerally, while its catheter was secured at a pars plana sclerotomy. The control group (n = 2) underwent sham surgeries in the form of a temporary suturing of the MicroPump, including placement of the pars plana tube. Baseline and follow-up exams included ophthalmic examination and imaging. The experimental animals were euthanized and explanted at predetermined time points after surgery (1, 3, and 12 months), while the control animals were euthanized at 3 months. All operated eyes were submitted for histopathology. RESULTS: Eyes were scored according to a modified McDonald-Shadduck system and ophthalmic imaging. Neither the implanted eyes nor the control eyes showed clinically significant pathological changes beyond the expected surgical changes. The operated eyes showed neither significant inflammatory reaction nor tissue ingrowth through the sclerotomy site compared with the fellow eyes. CONCLUSION: This study shows that the Replenish Posterior MicroPump could be successfully implanted with good safety profile in this animal model. TRANSLATIONAL RELEVANCE: The results of this study in a Beagle dog model are supportive of the biocompatibility of Replenish MicroPump and pave the way to the use of these devices for ocular automated drug delivery after further testing in larger animal models.