Marijuana use among young people in an era of policy change: what does recent evidence tell us?

R25 DA030310 - National Institute on Drug Abus

Reliability modeling of a 1-out-of-2 system: Research with diverse Off-the-shelf SQL database servers

Fault tolerance via design diversity is often the only viable way of achieving sufficient dependability levels when using off-the-shelf components. We have reported previously on studies with bug reports of four open-source and commercial off-the-shelf database servers and later release of two of them. The results were very promising for designers of fault-tolerant solutions that wish to employ diverse servers: very few bugs caused failures in more than one server and none caused failure in more than two. In this paper we offer details of two approaches we have studied to construct reliability growth models for a 1-out-of-2 fault-tolerant server which utilize the bug reports. The models presented are of practical significance to system designers wishing to employ diversity with off-the-shelf components since often the bug reports are the only direct dependability evidence available to them

c-Myc induced changes in higher order rDNA structure accompany growth factor stimulation of quiescent cells

Human c-Myc is believed to be a high level coordinator of protein synthesis capacity and cell growth rate, capable of activating transcription by all three nuclear RNA Polymerases. Direct activation of rDNA transcription by c-Myc is functionally conserved in rat cells, despite high divergence in non-coding rDNA sequences, suggesting that this coordinating role is likely to be a general within mammals. Upon re-feeding of starved cells, c-Myc activity enhances the efficiency of RNA Polymerase I and SL1/TIF-1B recruitment to the rDNA and rapidly induces higher order gene loop structures in rDNA chromatin that juxtapose upstream and downstream rDNA sequences. Furthermore c-Myc induced gene-loop formation in rDNA genes occurs independently of rDNA transcription, implying that it may be an early step in the re-programming of quiescent cells as they enter the growth cycle

Behavioral risk profiles of homeschooled adolescents in the United States: a nationally representative examination of substance use related outcomes

BACKGROUND: The homeschool population continues to grow in size and now accounts for 3.4% of all students in the United States. OBJECTIVE: Given the heterogeneous nature of the population, this study examines the relationship between different types of homeschoolers and a number of substance use related outcomes. METHODS: To conduct this study, we used pooled data (2002–2013) from the National Survey on Drug Use and Health (NSDUH). Respondents aged 12–17 who reported they had been homeschooled at any time during the previous 12 months were classified as homeschoolers (N = 1,321). Latent profile analysis (LPA) was conducted to identify latent subgroups of homeschoolers and multinomial regression was executed to assess the relationship between the subgroups and perceived substance use risk, availability, and past 12-month use. RESULTS: The LPA yielded four subgroups, which were summarized as (1) highly religious and engaged, (2) limited parental monitoring, (3) high parental warmth and support, and (4) secular permissive. Of these, the highly religious and engaged subgroup was the least likely to report using substances. CONCLUSION: The results underscore the variation that exists among homeschoolers and the importance of examining the relationship between different types of homeschoolers and outcomes of interest

Handgun carrying among youth in the United States

Despite a wealth of research finding that adolescents who carry handguns are involved in risky behaviors, there has been little exploration into the heterogeneity of this behavior. Using a pooled sample of 12- to 17-year-olds from the National Study on Drug Use and Health who report past-year handgun carrying (N = 7,872), this study identified four subgroups of handgun carriers: low risk (n = 3,831; 47.93%), alcohol and marijuana users (n = 1,591; 20.16%), fighters (n = 1,430; 19.40%), and severe externalizers (n = 1,020, 12.51%). These subgroups differed on demographic, behavioral, and psychosocial characteristics. Findings are discussed in light of prevention and focused deterrence

Quantum state transfer between a Bose-Einstein condensate and an optomechanical mirror

In this paper we describe a scheme for state transfer between a trapped atomic Bose condensate and an optomechanical end-mirror mediated by a cavity field. Coupling between the mirror and the cold gas arises from the fact that the cavity field can produce density oscillations in the gas which in turn acts as an internal Bragg mirror for the field. After adiabatic elimination of the cavity field we find that the hybrid system of the gas and mirror is described by a beam splitter Hamiltonian that allows for state transfer, but only if the quantum nature of the cavity field is retained