Smoking and suicidal ideation among college students: Smoking expectancies as potential moderators.

Objective: In the present study, we sought to establish a link between suicidal ideation (SI) and smoking in college students, determine whether psychopathology accounted for the association, and determine whether smoking expectancies were moderators. Participants: Participants (N = 607) were identified as nonsmokers, exsmokers, infrequent smokers, or daily smokers. Methods: Participants were assessed for smoking patterns, smoking expectancies, psychopathology, SI, and past suicide attempts. Results: Daily smokers had the highest level of SI. There was a dose-response relationship between smoking and SI, such that the higher the daily smoking rate, the greater the SI, even when controlling for depression, alcohol use, and drug use. Trend-level results indicated that at lower smoking rates, elevated smoking-related negative affect reduction (NAR) expectancies were associated with lower SI, while elevated NAR expectancies in combination with higher smoking rates were associated with greater SI. Conclusion: Smoking cessation programs for college students should screen for SI.

The association between problematic alcohol use, risk perceptions, and e-cigarette use.

Background: Use of e-cigarettes among college students has escalated, in part due to the perception that they are less harmful than traditional cigarettes and have other benefits such as circumventing smoking bans. College students also drink more heavily than other age groups, and e-cigarettes are associated with alcohol, especially among students who engage in problematic drinking.Objective: The present study sought to determine if an interaction between problematic alcohol use and increased perceptions of benefits and decreased perceptions of risks of e-cigarettes would predict whether participants had ever used an e-cigarette.Method: The present study included 1,133 undergraduate college students surveyed between November 2014 - November 2016. Participants were primarily Caucasian (82.3%) and female (78.1%). Participants completed questionnaires regarding demographics, smoking status/history, and expectancies.Results: Higher levels of problematic drinking and higher perceived benefits of e-cigarette use were both associated with having tried e-cigarettes. This relationship was significant even when controlling for several covariates such as cigarettes smoking status. However, there was not a significant interaction between problematic alcohol use and perceived benefits or risks of e-cigarettes. There was also no relationship between risk perceptions of e-cigarettes and e-cigarettes use.Conclusions: Both problematic alcohol use and perception of benefits of e-cigarettes were associated with having tried an e-cigarette. This finding is problematic as the use of e-cigarettes may influence further engagement in risky behaviors including problematic drinking or transitioning to regular cigarette use. Thus, it is important to develop interventions to help college students develop more accurate risk perceptions about e-cigarettes.

Dual users of e-cigarettes and cigarettes have greater positive smoking expectancies than regular smokers: a study of smoking expectancies among college students.

Objective: In the present study, we sought to determine the differences among college students using e-cigarettes, cigarettes, or both products (dual users) on smoking outcome expectancies and the role of smoking expectancies and e-cigarette use in cessation attempts. Participants: We surveyed 1,370 undergraduate college students from November 2014 to November 2016. Methods: Participants completed questionnaires regarding demographics, smoking status/history, and expectancies. Results: Dual users reported significantly longer smoking histories and more past quit attempts than other smoking groups. Those reporting dual use reported higher expectancies on positive/negative reinforcement and appetite/weight control subscales of the SCQ. E-cigarette use was a negative predictor of cessation attempts. Conclusions: College students appear to be less motivated to use e-cigarettes for cessation and dual users endorsed higher levels of smoking expectancies previously shown to negatively impact treatment outcomes. Students, especially dual users, need targeted interventions to address the dangers of using tobacco products.

Financial strain mediates the relationship between socioeconomic status and smoking.

INTRODUCTION: Smoking is the leading cause of preventable death accounting for about 0.48 million deaths in the US every year. Across the socioeconomic status (SES) gradient smoking prevalence differs greatly, with those of lower SES smoking at much higher rates than those of higher SES. Previous studies have shown relationships between socioeconomic status, financial strain, and smoking. However, little research has explored the possibility that financial strain might mediate the relationship between socioeconomic status and smoking. Thus, the goal of the current study was to determine whether financial strain was a mediating factor in the relationship between socioeconomic status and smoking. METHODS: Participants (N=238) were primarily female (67.6%) and African-American adults (51.7%) from the Dallas metropolitan area. The majority of the sample reported that they did not currently smoke (n=164). Participants who reported currently smoking at baseline (n=74) smoked an average of 9.96 (SD=10.79) cigarettes per day. RESULTS: Analyses revealed that financial strain partially mediates the relationship between socioeconomic status and smoking status. Additionally, financial strain was found to significantly partially mediate the relationship between socioeconomic status and cigarettes smoked prospectively over the next 7 days. CONCLUSIONS: Overall, findings suggest that greater financial strain may be one factor that links SES with current smoking and smoking level among those who smoke.

Motivation and readiness for tobacco cessation among nicotine dependent postmenopausal females: A pilot study.

Despite considerable health risks due to lower levels of estrogen production and the compounding antiestrogenic effects of nicotine, postmenopausal females continue to smoke. These females face significant barriers to cessation, including negative affect, weight concerns, and menopausal symptom severity. The current pilot study explored the effect of negative affect, weight concerns, and menopausal symptom severity on motivation and readiness to quit smoking. Eighteen postmenopausal smokers were randomized to receive brief motivational interviewing (B-MI; n = 8) or control treatment (i.e., a 1-hour video, n = 10). Participants completed measures of negative affect, weight concerns, and menopausal symptoms, as well as measures of motivation and readiness to quit. Motivation and readiness to quit were reassessed one week following treatment. At baseline, weight concerns, specifically surrounding smoking to prevent overeating, were identified as related to increased motivation to quit smoking. Menopausal symptom severity, specifically somatic symptoms, assessed at baseline, was associated with increased readiness for cessation. B-MI did not increase motivation or readiness to quit; however, results indicate that cigarettes per day decreased from baseline to follow-up by approximately 20-30%. These results provide valuable insight into enhancing engagement in a cessation treatment among this population. (PsycINFO Database Record

Understanding the link between contingency management and smoking cessation: The roles of sex and self-efficacy.

INTRODUCTION: Little is known about the mechanisms linking contingency management (CM) treatment with smoking cessation, and recent research suggests that the CM approach is associated with better smoking cessation outcomes among females than males. The current study investigated self-efficacy as a potential mechanism through which CM treatment influences smoking cessation, and explored whether these relationships differed by sex. METHODS: Participants (N = 139) were primarily Black (63.3%) and female (57.6%) adults enrolled in a safety-net hospital smoking cessation program. Participants received usual care (UC), which included pharmacotherapy and counseling sessions (n = 66) or a CM intervention (UC + 4 weeks of small, abstinence contingent financial incentives; n = 73). Self-efficacy for quitting was measured on the day after quitting with the Self-Efficacy Scale/Confidence (SESC) questionnaire. Mediation analyses were conducted to evaluate the indirect effects of treatment group on biochemically-verified abstinence (4-weeks post-quit) via self-efficacy, and moderated mediation analyses were conducted to evaluate the moderating role of sex. RESULTS: Self-efficacy was not found to mediate the relations between CM treatment and smoking cessation in the overall sample. However, analyses indicated a significant moderating effect of sex on the indirect effect of treatment group on smoking cessation through self-efficacy (each of the 3 SESC subscales). Specifically, there was a stronger association between CM and greater self-efficacy among females than males. CONCLUSION: Findings suggest that CM treatment had a differing impact on self-efficacy among males and females, which in turn influenced the likelihood of smoking cessation.

Financial strain indirectly influences smoking cessation through withdrawal symptom severity.

BACKGROUND: Financial strain has an adverse impact on smoking cessation. However, the mechanisms through which financial strain influences cessation remain unclear. The purpose of the current study was to determine whether financial strain indirectly influenced smoking cessation through withdrawal symptom severity. METHODS: Participants (N=139) were primarily Black (63.3%) and female (57.6%) adults enrolled in a smoking cessation program at a safety-net hospital. A self-report financial strain questionnaire was completed one week prior to the scheduled quit date, and the Wisconsin Smoking Withdrawal Scale (WSWS) was completed on the day after the scheduled quit date. Biochemically-verified 7-day point prevalence abstinence was assessed four weeks after the scheduled quit date. Adjusted mediation analyses were conducted using the PROCESS macro for SPSS to evaluate the indirect effects of financial strain on smoking cessation via post-quit withdrawal symptom severity. RESULTS: Analyses indicated a significant indirect effect of financial strain on smoking cessation through total withdrawal symptom severity, B=0.027; 95% CI (0.003, 0.066); and specifically anger, B=0.035; 95% CI (0.008, 0.074), anxiety, B=0.021; 95% CI (0.001, 0.051), and sleep symptoms, B=0.015; 95% CI (0.005, 0.043). Greater pre-quit financial strain was associated with greater post-quit withdrawal symptom severity, which increased the likelihood of non-abstinence 4 weeks after the scheduled quit attempt. The direct effect of financial strain on smoking cessation was not significant in any of the mediation models. CONCLUSIONS: Findings: suggest that withdrawal severity is an underlying mechanism through which financial strain influences smoking cessation.

Electrical stimulation enhances the acetylcholine receptors available for neuromuscular junction formation.

Neuromuscular junctions (NMJ) are specialized synapses that link motor neurons with muscle fibers. These sites are fundamental to human muscle activity, controlling swallowing and breathing amongst many other vital functions. Study of this synapse formation is an essential area in neuroscience; the understanding of how neurons interact and control their targets during development and regeneration are fundamental questions. Existing data reveals that during initial stages of development neurons target and form synapses driven by biophysical and biochemical cues, and during later stages they require electrical activity to develop their functional interactions. The aim of this study was to investigate the effect of exogenous electrical stimulation (ES) electrodes directly in contact with cells, on the number and size of acetylcholine receptor (AChR) clusters available for NMJ formation. We used a novel in vitro model that utilizes a flexible electrical stimulation system and allows the systematic testing of several stimulation parameters simultaneously as well as the use of alternative electrode materials such as conductive polymers to deliver the stimulation. Functionality of NMJs under our co-culture conditions was demonstrated by monitoring changes in the responses of primary myoblasts to chemical stimulants that specifically target neuronal signaling. Our results suggest that biphasic electrical stimulation at 250Hz, 100µs pulse width and current density of 1mA/cm2 for 8h, applied via either gold-coated mylar or the conductive polymer PPy, significantly increased the number and size of AChRs clusters available for NMJ formation. This study supports the beneficial use of direct electrical stimulation as a strategic therapy for neuromuscular disorders. STATEMENT OF SIGNIFICANCE: The beneficial effects of electrical stimulation (ES) on human cells in vitro and in vivo have long been known. Although the effects of stimulation are clear and the therapeutic benefits are known, no uniform parameters exist with regard to the duration, frequency and amplitude of the ES. To this end, we are answering several important questions on the parameters for ES of nerve and muscle monocultures and co-cultures by probing the effects on the enhancement of acetylcholine receptors (AChR) clustering available for neuromuscular junction formation using a conductive platform. This work opens the possibility to combine electrical stimulus delivered via conductive polymer substrates, from which biomolecules could also be delivered, providing opportunities to further enhance the therapeutic effect.

Modeling huddling penguins.

We present a systematic and quantitative model of huddling penguins. In this mathematical model, each individual penguin in the huddle seeks only to reduce its own heat loss. Consequently, penguins on the boundary of the huddle that are most exposed to the wind move downwind to more sheltered locations along the boundary. In contrast, penguins in the interior of the huddle neither have the space to move nor experience a significant heat loss, and they therefore remain stationary. Through these individual movements, the entire huddle experiences a robust cumulative effect that we identify, describe, and quantify. This mathematical model requires a calculation of the wind flowing around the huddle and of the resulting temperature distribution. Both of these must be recomputed each time an individual penguin moves since the huddle shape changes. Using our simulation results, we find that the key parameters affecting the huddle dynamics are the number of penguins in the huddle, the wind strength, and the amount of uncertainty in the movement of the penguins. Moreover, we find that the lone assumption of individual penguins minimizing their own heat loss results in all penguins having approximately equal access to the warmth of the huddle.

Uptake, elimination, and relative distribution of perchlorate in various tissues of channel catfish.

This study was undertaken to determine the kinetics of uptake and elimination of perchlorate in channel catfish, Ictalurus punctatus. Perchlorate--an oxidizer used in solid fuel rockets, fireworks, and illuminating munitions--has been shown to effect thyroid function, causing hormone disruption and potential perturbations of metabolic activities. For the uptake study, catfish were exposed to 100 mg/L sodium perchlorate for 12 h to 5 d in the laboratory. Perchlorate in tissues was analyzed using ion chromatography. The highest perchlorate concentrations were found in the head and fillet, indicating that these tissues are the most important tissues to analyze when determining perchlorate uptake into large fish. To calculate uptake and elimination rate constants for fillet, gills, G-I tract, liver, and head, fish were exposed to 100 ppm sodium perchlorate for 5 days, and allowed to depurate in clean water for up to 20 days. The animals rapidly eliminated the perchlorate accumulated showing the highest elimination in fillet (Ke = 1.67 day(-1)) and lowest elimination in liver (Ke = 0.79 day(-1)).

Perchlorate in fish from a contaminated site in east-central Texas.

Perchlorate, a known thyroid endocrine disruptor, contaminates surface waters near military instillations where solid fuel rocket motors are manufactured or assembled. To assess potential perchlorate exposure to fish and the human population which may feed on them, fish were collected around the Naval Weapons Industrial Reserve Plant in McLennan County, TX, and analyzed for the presence of the perchlorate anion. The sampling sites included Lake Waco and Belton Lake, and several streams and rivers within their watersheds. The general tendency was that perchlorate was only found in a few species sampled, and perchlorate was not detected in every individual within these species. When detected in the fish, perchlorate tissue concentrations were greater than that in the water. This may be due to highly variable perchlorate concentrations in the water coupled with individual-level variation in elimination from the body, or to routes of exposure other than water.