Basement and Regional Structure Along Strike of the Queen Charlotte Fault in the Context of Modern and Historical Earthquake Ruptures

The Queen Charlotte fault (QCF) is a dextral transform system located offshore of southeastern Alaska and western Canada, accommodating similar to 4.4 cm/yr of relative motion between the Pacific and North American plates. Oblique convergence along the fault increases southward, and how this convergence is accommodated is still debated. Using seismic reflection data, we interpret offshore basement structure, faulting, and stratigraphy to provide a geological context for two recent earthquakes, an M-w 7.5 strike-slip event near Craig, Alaska, and an M-w 7.8 thrust event near Haida Gwaii, Canada. We map downwarped Pacific oceanic crust near 54 degrees N, between the two rupture zones. Observed downwarping decreases north and south of 54 degrees N, parallel to the strike of the QCF. Bending of the Pacific plate here may have initiated with increased convergence rates due to a plate motion change at similar to 6 Ma. Tectonic reconstruction implies convergence-driven Pacific plate flexure, beginning at 6 Ma south of a 10 degrees bend the QCF (which is currently at 53.2 degrees N) and lasting until the plate translated past the bend by similar to 2 Ma. Normal-faulted approximately late Miocene sediment above the deep flexural depression at 54 degrees N, topped by relatively undeformed Pleistocene and younger sediment, supports this model. Aftershocks of the Haida Gwaii event indicate a normal-faulting stress regime, suggesting present-day plate flexure and underthrusting, which is also consistent with reconstruction of past conditions. We thus favor a Pacific plate underthrusting model to initiate flexure and accommodation space for sediment loading. In addition, mapped structures indicate two possible fault segment boundaries along the QCF at 53.2 degrees N and at 56 degrees N.USGS Earthquake Hazards External Grants ProgramNational Earthquake Hazards Reduction ProgramUTIG Ewing/Worzel FellowshipInstitute for Geophysic

Determinants of early alcohol and drug use among young women in alcoholism treatment

Substance abuse experimentation may be one of several types of problem behaviors. Data from 99 Caucasian women interviewed in alcoholism treatment (19-29 years old) were used to test a developmental model of substance experimentation. Responders were classified into three groups based on their use prior to age 15: nonusers, users of alcohol only, and users of alcohol and other drugs. Family history of alcoholism was not related to childhood anxiety and impulse control problems. Childhood anxiety and impulse control problems predicted adolescent emotional and impulse control problems but did not differentiate early experimenters. Whereas adolescent emotional problems were not related to early experimentation, early drug and alcohol users were significantly more likely to have engaged in other impulsive behaviors (e.g., running away from home, trouble with school authorities) than were nonusers or users of alcohol only. Alcoholism prevention programs, therefore, would do well to target youth who exhibit acting-out behaviors as a high-risk group for early alcohol and drug use.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31925/1/0000878.pd

Sexually Transmitted Infection History among Adolescents Presenting to the Emergency Department

BACKGROUND: Adolescents and young adults account for about half of the annual diagnoses of sexually transmitted infections (STI) in the United States. Screening and treatment for STIs, as well as prevention, are needed in health-care settings to help offset the costs of untreated STIs. OBJECTIVE: Our aim was to evaluate the prevalence and correlates of self-reported STI history among adolescents presenting to an emergency department (ED). METHODS: Over two and a half years, 4389 youth (aged 14-20 years) presenting to the ED completed screening measures for a randomized controlled trial. About half (56%) reported lifetime sexual intercourse and were included in analyses examining sexual risk behaviors (e.g., inconsistent condom use), and relationships of STI history with demographics (sex, age, race, school enrollment), reason for ED presentation (i.e., medical or injury), and substance use. RESULTS: Among sexually active youth, 10% reported that a medical professional had ever told them they had an STI (212 females, 35 males). Using logistic regression, female sex, older age, non-Caucasian race, not being enrolled in school, medically related ED chief complaint, and inconsistent condom use were associated with increased odds of self-reported STI history. CONCLUSIONS: One in 10 sexually active youth in the ED reported a prior diagnosed STI. Previous STI was significantly higher among females than males. ED providers inquiring about inconsistent condom use and previous STI among male and female adolescents may be one strategy to focus biological testing resources and improve screening for current STI

A randomized controlled trial testing the efficacy of a brief cannabis universal prevention program among adolescents in primary care

Aims To examine the efficacy of a brief intervention delivered by a therapist ( TBI ) or a computer ( CBI ) in preventing cannabis use among adolescents in urban primary care clinics. Design A randomized controlled trial comparing: CBI and TBI versus control. Setting Urban primary care clinics in the U nited S tates. Participants Research staff recruited 714 adolescents (aged 12–18 years) who reported no life‐time cannabis use on a screening survey for this study, which included a baseline survey, randomization (stratified by gender and grade) to conditions (control; CBI ; TBI ) and 3‐, 6‐ and 12‐month assessments. Measurements Using an intent‐to‐treat approach, primary outcomes were cannabis use (any, frequency); secondary outcomes included frequency of other drug use, severity of alcohol use and frequency of delinquency (among 85% completing follow‐ups). Findings Compared with controls, CBI participants had significantly lower rates of any cannabis use over 12 months (24.16%, 16.82%, respectively, P  < 0.05), frequency of cannabis use at 3 and 6 months ( P  < 0.05) and other drug use at 3 months ( P  < 0.01). Compared with controls, TBI participants did not differ in cannabis use or frequency, but had significantly less other drug use at 3 months ( P  < 0.05), alcohol use at 6 months ( P  < 0.01) and delinquency at 3 months ( P  < 0.01). Conclusions Among adolescents in urban primary care in the U nited S tates, a computer brief intervention appeared to prevent and reduce cannabis use. Both computer and therapist delivered brief interventions appeared to have small effects in reducing other risk behaviors, but these dissipated over time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106949/1/add12469.pd

Alcohol, Tobacco, and Other Drugs: Future Directions for Screening and Intervention in the Emergency Department

This article is a product of a breakout session on injury prevention from the 2009 Academic Emergency Medicine consensus conference on “Public Health in the ED: Screening, Surveillance, and Intervention.” The emergency department (ED) is an important entry portal into the medical care system. Given the epidemiology of substance use among ED patients, the delivery of effective brief interventions (BIs) for alcohol, drug, and tobacco use in the ED has the potential to have a large public health impact. To date, the results of randomized controlled trials of interventional studies in the ED setting for substance use have been mixed in regard to alcohol and understudied in the area of tobacco and other drugs. As a result, there are more questions remaining than answered. The work group developed the following research recommendations that are essential for the field of screening and BI for alcohol, tobacco, and other drugs in the ED. 1) Screening—develop and validate brief and practical screening instruments for ED patients and determine the optimal method for the administration of screening instruments. 2) Key components and delivery methods for intervention—conduct research on the effectiveness of screening, brief intervention, and referral to treatment (SBIRT) in the ED on outcomes (e.g., consumption, associated risk behaviors, and medical psychosocial consequences) including minimum dose needed, key components, optimal delivery method, interventions focused on multiple risk behaviors and tailored based on assessment, and strategies for addressing polysubstance use. 3) Effectiveness among patient subgroups—conduct research to determine which patients are most likely to benefit from a BI for substance use, including research on moderators and mediators of intervention effectiveness, and examine special populations using culturally and developmentally appropriate interventions. 4) Referral strategies—a) promote prospective effectiveness trials to test best strategies to facilitate referrals and access from the ED to preventive services, community resources, and substance abuse and mental health treatment; b) examine impact of available community services; c) examine the role of stigma of referral and follow-up; and d) examine alternatives to specialized treatment referral. 5) Translation—conduct translational and cost-effectiveness research of proven efficacious interventions, with attention to fidelity, to move ED SBIRT from research to practice.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78664/1/j.1553-2712.2009.00552.x.pd

Basement and Regional Structure Along Strike of the Queen Charlotte Fault in the Context of Modern and Historical Earthquake Ruptures

The Queen Charlotte fault (QCF) is a dextral transform system located offshore of southeastern Alaska and western Canada, accommodating ∼4.4 cm/yr of relative motion between the Pacific and North American plates. Oblique convergence along the fault increases southward, and how this convergence is accommodated is still debated. Using seismic reflection data, we interpret offshore basement structure, faulting, and stratigraphy to provide a geological context for two recent earthquakes, an M[subscript w] 7.5 strike-slip event near Craig, Alaska, and an M[subscript w] 7.8 thrust event near Haida Gwaii, Canada. We map downwarped Pacific oceanic crust near 54° N, between the two rupture zones. Observed downwarping decreases north and south of 54° N, parallel to the strike of the QCF. Bending of the Pacific plate here may have initiated with increased convergence rates due to a plate motion change at ∼6 Ma. Tectonic reconstruction implies convergence-driven Pacific plate flexure, beginning at 6 Ma south of a 10° bend the QCF (which is currently at 53.2° N) and lasting until the plate translated past the bend by ∼2 Ma. Normal-faulted approximately late Miocene sediment above the deep flexural depression at 54° N, topped by relatively undeformed Pleistocene and younger sediment, supports this model. Aftershocks of the Haida Gwaii event indicate a normal-faulting stress regime, suggesting present-day plate flexure and underthrusting, which is also consistent with reconstruction of past conditions. We thus favor a Pacific plate underthrusting model to initiate flexure and accommodation space for sediment loading. In addition, mapped structures indicate two possible fault segment boundaries along the QCF at 53.2° N and at 56° N

An Abrupt Transition in the Mechanical Response of the Upper Crust to Transpression along the Queen Charlotte Fault

The Queen Charlotte Fault (QCF) is a major strike-slip fault that forms the boundary between the Pacific and North American plates from 51° to 58° N. Near 53.2° N, the angle of oblique convergence predicted by the Mid-Ocean Ridge VELocity (MORVEL) interplate pole of rotation decreases from >15° in the south to <15° in the north. South of 53.2° N, the convergent component of plate motion results in the formation of a 40 km wide terrace on the Pacific plate west of QCF and earthquakes with thrust mechanisms (including the 2012 Haida Gwaii earthquake sequence) are observed. North of 53.2° N, in the primary rupture zone of the M 8.1 strike-slip earthquake of 1949, the linear terrace disappears, and topography of the continental slope west of the QCF is characterized by a complex pattern of ridges and basins that trend obliquely to the primary trace of the QCF. Deformation within the Pacific plate appears to occur primarily through strike-slip faulting with a minor thrust component on secondary synthetic faults. The orientations of these secondary faults, as determined from seismic reflection and bathymetric data, are consistent with the reactivation of faults originally formed as ridge-parallel normal faults and as thrust faults formed parallel to the QCF south of the bend at 53.2° N and subsequently translated to the north. We suggest that an oblique convergence angle of 15° represents a critical threshold separating distinct crustal responses to transpression. This result is consistent with theoretical and analog strain models of transpressive plate boundaries. The sharpness of this transition along the QCF, in contrast to purely continental transform boundaries, may be facilitated by the relatively simple structure of oceanic crust and the presence of pre-existing, optimally oriented faults in the young Pacific plate

The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>This is the second in a series of three articles documenting the geographical distribution of 41 dominant vector species (DVS) of human malaria. The first paper addressed the DVS of the Americas and the third will consider those of the Asian Pacific Region. Here, the DVS of Africa, Europe and the Middle East are discussed. The continent of Africa experiences the bulk of the global malaria burden due in part to the presence of the <it>An. gambiae </it>complex. <it>Anopheles gambiae </it>is one of four DVS within the <it>An. gambiae </it>complex, the others being <it>An. arabiensis </it>and the coastal <it>An. merus </it>and <it>An. melas</it>. There are a further three, highly anthropophilic DVS in Africa, <it>An. funestus</it>, <it>An. moucheti </it>and <it>An. nili</it>. Conversely, across Europe and the Middle East, malaria transmission is low and frequently absent, despite the presence of six DVS. To help control malaria in Africa and the Middle East, or to identify the risk of its re-emergence in Europe, the contemporary distribution and bionomics of the relevant DVS are needed.</p> <p>Results</p> <p>A contemporary database of occurrence data, compiled from the formal literature and other relevant resources, resulted in the collation of information for seven DVS from 44 countries in Africa containing 4234 geo-referenced, independent sites. In Europe and the Middle East, six DVS were identified from 2784 geo-referenced sites across 49 countries. These occurrence data were combined with expert opinion ranges and a suite of environmental and climatic variables of relevance to anopheline ecology to produce predictive distribution maps using the Boosted Regression Tree (BRT) method.</p> <p>Conclusions</p> <p>The predicted geographic extent for the following DVS (or species/suspected species complex*) is provided for Africa: <it>Anopheles </it>(<it>Cellia</it>) <it>arabiensis</it>, <it>An. </it>(<it>Cel.</it>) <it>funestus*</it>, <it>An. </it>(<it>Cel.</it>) <it>gambiae</it>, <it>An. </it>(<it>Cel.</it>) <it>melas</it>, <it>An. </it>(<it>Cel.</it>) <it>merus</it>, <it>An. </it>(<it>Cel.</it>) <it>moucheti </it>and <it>An. </it>(<it>Cel.</it>) <it>nili*</it>, and in the European and Middle Eastern Region: <it>An. </it>(<it>Anopheles</it>) <it>atroparvus</it>, <it>An. </it>(<it>Ano.</it>) <it>labranchiae</it>, <it>An. </it>(<it>Ano.</it>) <it>messeae</it>, <it>An. </it>(<it>Ano.</it>) <it>sacharovi</it>, <it>An. </it>(<it>Cel.</it>) <it>sergentii </it>and <it>An. </it>(<it>Cel.</it>) <it>superpictus*</it>. These maps are presented alongside a bionomics summary for each species relevant to its control.</p

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202

Dissecting the Shared Genetic Architecture of Suicide Attempt, Psychiatric Disorders, and Known Risk Factors

Background Suicide is a leading cause of death worldwide, and nonfatal suicide attempts, which occur far more frequently, are a major source of disability and social and economic burden. Both have substantial genetic etiology, which is partially shared and partially distinct from that of related psychiatric disorders. Methods We conducted a genome-wide association study (GWAS) of 29,782 suicide attempt (SA) cases and 519,961 controls in the International Suicide Genetics Consortium (ISGC). The GWAS of SA was conditioned on psychiatric disorders using GWAS summary statistics via multitrait-based conditional and joint analysis, to remove genetic effects on SA mediated by psychiatric disorders. We investigated the shared and divergent genetic architectures of SA, psychiatric disorders, and other known risk factors. Results Two loci reached genome-wide significance for SA: the major histocompatibility complex and an intergenic locus on chromosome 7, the latter of which remained associated with SA after conditioning on psychiatric disorders and replicated in an independent cohort from the Million Veteran Program. This locus has been implicated in risk-taking behavior, smoking, and insomnia. SA showed strong genetic correlation with psychiatric disorders, particularly major depression, and also with smoking, pain, risk-taking behavior, sleep disturbances, lower educational attainment, reproductive traits, lower socioeconomic status, and poorer general health. After conditioning on psychiatric disorders, the genetic correlations between SA and psychiatric disorders decreased, whereas those with nonpsychiatric traits remained largely unchanged. Conclusions Our results identify a risk locus that contributes more strongly to SA than other phenotypes and suggest a shared underlying biology between SA and known risk factors that is not mediated by psychiatric disorders.Peer reviewe