Characterizing Polytobacco Use Trajectories and Their Associations With Substance Use and Mental Health Across Mid-Adolescence.

Background:Polytobacco product use is suspected to be common, dynamic across time, and increase risk for adverse behavioral outcomes. We statistically modeled characteristic types of polytobacco use trajectories during mid-adolescence and tested their prospective association with substance use and mental health problems. Methods:Adolescents (N = 3393) in Los Angeles, CA, were surveyed semiannually from 9th to 11th grade. Past 6-month combustible cigarette, e-cigarette, or hookah use (yes/no) over four assessments were analyzed using parallel growth mixture modeling to identify a parsimonious set of polytobacco use trajectories. A tobacco product use trajectory group was used to predict substance use and mental health at the fifth assessment. Results:Three profiles were identified: (1) tobacco nonusers (N = 2291, 67.5%) with the lowest use prevalence (<3%) of all products across all timepoints; (2) polyproduct users (N = 920, 27.1%) with moderate use prevalence of each product (8-35%) that escalated for combustible cigarettes but decreased for e-cigarettes and hookah across time; and (3) chronic polyproduct users (N = 182, 5.4%) with high prevalence of each product use (38-86%) that escalated for combustible cigarettes and e-cigarettes. Nonusers, polyproduct users, and chronic polyproduct users reported successively higher alcohol, marijuana, and illicit drug use and ADHD at the final follow-up, respectively. Both tobacco using groups (vs. nonusers) reported greater odds of depression and anxiety at the final follow-up but did not differ from each other. Conclusions:Adolescent polytobacco use may involve a common moderate risk trajectory and a less common high-risk chronic trajectory. Both trajectories predict substance use and mental health symptomology. Implications:Variation in use and co-use of combustible cigarette, e-cigarette, and hookah use in mid-adolescence can be parsimoniously characterized by a small set common trajectory profiles in which polyproduct use are predominant patterns of tobacco product use, which predict adverse behavioral outcomes. Prevention and policy addressing polytobacco use (relative to single product use) may be optimal tobacco control strategies for youth, which may in turn prevent other forms of substance use and mental health problems

Factors relating to patronage of purchasing cooperatives by 107 Middle Tennessee farmers

Many students divide the administration of cooperative associations into two distinct parts or functions. J. W. Jones’¹ divisions are as follows: “First, business administration, which includes financing, processing and merchandising the commodities handled, and supervision of credits and collections and second, membership administration which includes the maintenance of agreeable human relationships.” Membership relations have been an area of great importance in cooperative associations as well as in other business organizations. J. P. Warbasse² in his book, Problems of Cooperation, considers the errors of educational and social work real causes of the failure of many societies

Oxidation of the 1‐naphthyl radical C₁₀H₇• with oxygen: Thermochemistry, kinetics, and possible reaction pathways

The reaction of the 1-naphthyl radical C10H7• (A2•) with molecular (3O2) and atomic oxygen, as part of the oxidation reactions of naphthalene, is examined using ab-initio and DFT quantum chemistry calculations. The study focuses on pathways that produce the intermediate final products CO, phenyl and C2H2, which may constitute a repetitive reaction sequence for the successive diminution of six-membered rings also in larger polycyclic aromatic hydrocarbons. The primary attack of 3O2 on the 1-naphthyl radical leads to a peroxy radical C10H7OO• (A2OO•), which undergoes further propagation and/or chain branching reactions. The thermochemistry of intermediates and transition state structures is investigated as well as the identification of all plausible reaction pathways for the A2• + O2 / A2• + O systems. Structures and enthalpies of formation for the involved species are reported along with transition state barriers and reaction pathways. Standard enthalpies of formation are calculated using ab initio (CBS-QB3) and DFT calculations (B3LYP, M06, APFD). The reaction of A2• with 3O2 opens six main consecutive reaction channels with new ones not currently considered in oxidation mechanisms. The reaction paths comprise important exothermic chain branching reactions and the formation of unsaturated oxygenated hydrocarbon intermediates. The primary attack of 3O2 at the A2• radical has a well depth of some 50 kcal mol−1 while the six consecutive channels exhibit energy barriers below the energy of the A2• radical. The kinetic parameters of each path are determined using chemical activation analysis based on the canonical transition state theory calculations. The investigated reactions could serve as part of a comprehensive mechanism for the oxidation of naphthalene. The principal result from this study is that the consecutive reactions of the A2• radical, viz. the channels conducting to a phenyl radical C6H5•, CO2, CO (which oxidized to CO2) and C2H2 are by orders of magnitude faster than the activation of naphthalene by oxygen (A2 + O2 → A2• + HO2)

Exploring the anisotropic HISQ (aHISQ) action

The fate of heavy quarkonia states in quark-gluon plasma is encoded in the temperature dependence of their spectral functions. Reconstruction of spectral functions from Euclidean lattice correlators is an ill-posed problem. Despite a variety of techniques developed recently, many questions remain unresolved. It is known that the situation may be improved using anisotropic ensembles that provide finer resolution in the temporal direction. To date, the effort focused on Wilson fermions. We report on our first study with anisotropic improved staggered quarks. To compute the spectrum of the anisotropic Highly Improved Staggered Quarks (aHISQ) we generated a library of anisotropic pure gauge ensembles. We discuss the gauge anisotropy tuning that is performed with the Wilson and Symanzik gradient flow, as well as tuning of the strange quark mass and quark anisotropy with aHISQ, using spectrum measurements on quenched ensembles. Finally, we discuss the impact of anisotropy on pion taste splittings for aHISQ.Comment: 8 pages, 4 figures, The 40th International Symposium on Lattice Field Theory (Lattice 2023), July 31st - August 4th, 2023, Fermi National Accelerator Laborator

A CFD Study of the Performance of Horizontal Dilution Tubes

Since about 20 years, horizontal dilution tubes are in use to study soot formation close to the main reaction zone, in order to characterize the properties of nascent soot nanoparticles and to obtain insight into the soot formation process. In this study, the performance of horizontal dilution tubes, both free standing and embedded, is investigated by RANS and LES. The flame gas enters the dilutionctube through a pinhole and, in experimental studies, it is claimed to mix quickly with the cold, inert gas flow in the dilution tube. Previously, the distortion of the flow and temperature profiles around the dilution tube were investigated. Here, the orifice flow as well as the dilution process inside the tube are studied. The volume flow through the orifice is shown to be proportional to the square root of the pressure drop. The discharge coefficient is the range 0.9 0.3 in the cold air (calibration) case and drops to 0.35 under hot (flame) conditions. The resulting dilution ratio is roughly a factor of 5 below typical literature data. The gas sample is found to remain in the wall boundary layer and, the mixing process is not complete at the end of the dilution tube. Turbulence decays rapidly behind the tube inlet and, in the main body of the tube, the flow is in the laminar to turbulent transition regime. Turbulence increases significantly in the outlet section which has much smaller pipe cross sections. Despite its relatively low Reynolds number, the outlet flow to the particle sizer (or to the gas analyzer) is clearly turbulent and, interactions with the wall are probable. The results are in agreement with previouscfindings from laminar jets in crossflow. Guidelines for optimization of the sampling conditions are suggested