Characterization of off-axis fishbones

Repetitive bursting instabilities with strong frequency chirping occur in highbeta, beam-heated plasmas with safety factor q > 1 in the DIII-D tokamak. Although the mode structures differ, in many ways, the off-axis fishbones are similar to the q = 1 fishbones first observed on the Poloidal Divertor Experiment (PDX). The modes are driven by energetic trapped ions at the fastion precession frequency. During a burst, the frequency changes most rapidly as the mode reaches its maximum amplitude. Larger amplitude bursts have larger growth rates and frequency chirps. Unlike PDX fishbones, the decay phase is highly variable and is usually shorter than the growth phase. Also, the waveform is highly distorted by higher harmonics during the latter portion of a burst. The radial mode structure alters its shape during the burst. Like PDX fishbones, the modes expel trapped ions in a ‘beacon’ with a definite phase relationship relative to the mode. Seven types of loss detectors measure the beacon. The losses scale linearly with mode amplitude. The neutron rate changes most rapidly at maximum mode amplitude but, depending on the loss diagnostic, the losses often peak a few cycles later. The non-ambipolar fast-ion losses cause a sudden change in toroidal rotation frequency across the entire plasma. In addition to an overall drop, the neutron signal oscillates in response to the wave. Unlike the beacon of lost particles, which maintains a fixed phase relative to the mode, the phase of the neutron oscillations steadily increases throughout the burst, with the greatest phase slippage occurring in the highly nonlinear phase near maximum mode amplitudeUS Department of Energy SC-G903402, DE-FC02-04ER54698, DE-FG02-07ER5491

Prevalence of Injuries Among Medicaid Enrolled Infants Prior to Child Abuse and Neglect

Prior research has identified common injuries among children who experience child maltreatment; however, most of this work has focused on inpatient settings and has excluded many cases of neglect. This study examines the prevalence of injuries that occur prior to a diagnosis of child maltreatment, as well as the proportion of children with well-child visits prior to the injury and child maltreatment diagnosis. Based on a secondary analysis of Medicaid data from four states, we found that among infants with 12 months of continuous enrollment (N = 4817), 30.6% of those diagnosed with maltreatment were previously diagnosed with an injury. Among infants diagnosed with child maltreatment, 88.4% had at least one well-child visit prior to the maltreatment diagnosis. Among children with a maltreatment diagnosis and a prior injury, 84% had at least one well-child visit preceding the injury. These results indicate that most children had at least one well-child visit prior to being diagnosed with child maltreatment or an injury, indicating opportunities for prevention

Directed acyclic graphs: An under-utilized tool for child maltreatment research

Background: Child maltreatment research involves modeling complex relationships between multiple interrelated variables. Directed acyclic graphs (DAGs) are one tool child maltreatment researchers can use to think through relationships among the variables operative in a causal research question and to make decisions about the optimal analytic strategy to minimize potential sources of bias. Objective: The purpose of this paper is to highlight the utility of DAGs for child maltreatment research and to provide a practical resource to facilitate and support the use of DAGs in child maltreatment research. Results: We first provide an overview of DAG terminology and concepts relevant to child maltreatment research. We describe DAG construction and define specific types of variables within the context of DAGs including confounders, mediators, and colliders, detailing the manner in which each type of variable can be used to inform study design and analysis. We then describe four specific scenarios in which DAGs may yield valuable insights for child maltreatment research: (1) identifying covariates to include in multivariable models to adjust for confounding; (2) identifying unintended effects of adjusting for a mediator; (3) identifying unintended effects of adjusting for multiple types of maltreatment; and (4) identifying potential selection bias in data specific to children involved in the child welfare system. Conclusions: Overall, DAGs have the potential to help strengthen and advance the child maltreatment research and practice agenda by increasing transparency about assumptions, illuminating potential sources of bias, and enhancing the interpretability of results for translation to evidence-based practice

Identifying conservation units after large-scale land clearing: a spatio-temporal molecular survey of endangered white-tailed black cockatoos (Calyptorhynchus spp.)

Aim: We examined how the threatened and endemic white-tailed black cockatoos of Western Australia have responded genetically to recent and comprehensive habitat loss with the ultimate aim of identifying units for conservation. We assessed the population structure, connectivity and genetic diversity at spatial and temporal scales for Calyptorhynchus baudinii and C. latirostris, which have undergone dramatic population declines. Genetic comparisons of pre- and post-population decline were carried out by including historical samples dating back to 1920. We examined samples collected from across 700 km of their distribution and sampled approximately 1% of the current population census size to produce significant insights into the population genetics of white-tailed black cockatoos and generate genetic information crucial for conservation management. Location: Southwest corner of Western Australia. Methods: Six hundred and eighty-four cockatoo samples were collected from 1920 to 2010 and profiled with 19 microsatellites to identify spatial population structure and loss of genetic diversity.Results: The temporal and spatial microsatellite data illustrated that the geographically defined genetic structuring in white-tailed black cockatoos is likely to represent a recent phenomenon. We identified: (1) spatial population substructure east and west of extensively cleared habitat (>95,800 km2), but the historical samples clustered with the current western population, regardless of origin, (2) a regional loss of allelic diversity over 3–4 generations for the current eastern population, (3) a lack of a genetic signal of the recent population decline, but perhaps a mid-Holocene population collapse and lastly, (4) limited genetic differentiation between the two currently recognized white-tailed black-cockatoo species suggests a review of taxonomy and/or management units should be undertaken. Main conclusion: Based on extensive spatio-temporal sampling, we have demonstrated that recent anthropogenic habitat modifications have affected the genetic structure of a long-lived and highly mobile species. Our results have identified areas of high conservation value and the importance of maintaining native vegetation migration corridors

Hysteresis relation between turbulence and temperature modulation during the heat pulse propagation into a magnetic island in DIII-D

The hysteresis relation between turbulence and temperature modulation during the heat pulse propagation into a magnetic island is studied for the first time in toroidal plasmas. Lissajous curves of the density fluctuation (˜n/n) and the electron temperature (Te) modulation show that the (˜n/n) propagation is faster than the heat pulse propagation near the O point of the magnetic island. This faster ˜n/n propagation is experimental evidence of the turbulence spreading from the X point to the O point of the magnetic island

Trends in unintentional polysubstance overdose deaths and individual and community correlates of polysubstance overdose, North Carolina, 2009-2018

Background: Polysubstance involvement is increasing among fatal drug overdoses. However, little is known about the epidemiology of polysubstance drug overdoses. This paper describes emerging trends in unintentional polysubstance overdose deaths in North Carolina (NC) and examines associations with individual and community factors. Methods: Using 2009–2018 NC death certificate data, we identified unintentional drug overdose deaths and commonly involved substances (opioids, stimulants, benzodiazepines, alcohol, and antiepileptics). We examined polysubstance combinations, comparing opioid and non-opioid involved deaths. We examined individual level correlates from death certificate data and community level correlates from the American Community Survey and Robert Wood Johnson Foundation County Health Rankings to quantify associations. Results: From 2009–2018, 53 % of opioid and 19 % of non-opioid overdose deaths involved multiple substances. During this period, polysubstance overdose death increased dramatically, from 2.9 to 12.1 per 100,000 persons, with the greatest increases among drug combinations involving stimulants. The most common polysubstance combinations were: opioids and stimulants (12.1 % of overdose deaths); opioids and benzodiazepines (9.0 %); opioids and alcohol (5.1 %); opioids, stimulants, and benzodiazepines (3.1 %); and opioids, benzodiazepines, and antiepileptics (2.2 %). Compared to overdoses involving opioids alone, overdoses involving combinations of opioids, stimulants, and benzodiazepines involved younger individuals (53.7 % in 15−34 years of age vs. 40.7 %). Men comprised two-thirds of overdoses involving opioids alone, however, overdoses involving opioids, benzodiazepines, and antiepileptics were predominantly among women (60.6 %). Conclusions: Polysubstance involvement has increased among overdose deaths in NC. These findings can be used to inform public health interventions addressing polysubstance deaths and associated individual and community level factors

Preconception and Prenatal Predictors of Early Experiences of Risk and Protection Among Alaska Children

Objectives: Our objective was to identify preconception and prenatal predictors of early experiences of co-occurring risk and protective factors to help target prevention efforts to the highest-need families prior to the birth of the child. Methods: Data were from the Alaska Longitudinal Child Abuse and Neglect Linkage project and the 2012–2014 Alaska Child Understanding Behaviors Survey. We used latent class analysis and Vermunt’s three-step approach to examine predictors of latent classes of risk and protective factors among Alaska children. Results: Among children of Alaska Native/American Indian mothers, financial (OR 2.02, 95% CI 1.04, 3.90) and partner stress (OR 2.06, 95% CI 1.02, 4.10) prior to childbirth, maternal education < 12 years (OR 2.29, 95% CI 1.05, 4.96), and maternal substance use (OR 2.52, 95% CI 1.30, 4.89) were associated with a higher likelihood of membership in a high risk/moderate protection class as compared to a low socioeconomic status/high protection class. Among children of non-Native mothers, partner stress prior to childbirth (OR 3.92, 95% CI 1.08, 14.19), maternal education < 12 years (OR 2.69, 95% CI 1.24, 5.81), maternal substance use (OR 2.69, 95% CI 1.24, 5.81), younger maternal age (OR 0.87, 95% CI 0.80, 0.95), and a greater number of children (OR 1.62, 95% CI 1.09, 2.41) were associated with a higher likelihood of membership in a moderate risk/high protection class as compared to a low risk/moderate protection class. Conclusions: Results can inform eligibility criteria for prenatal home visiting programs and prenatal screening in Alaska to ensure prevention programming and referrals are directed to families most in need of additional support

Heterogeneity in Risk and Protection Among Alaska Native/American Indian and Non-Native Children

Currently, little is known about patterns of co-occurring risk and protective factors among young children. Understanding variations in co-occurring risk and protective factors among children in Alaska is important as experiences of collective trauma may contribute to differences in the intersection of risk and protective factors between Alaska Native/American Indian (AN/AI) and non-Native children. Using data from the Alaska Longitudinal Child Abuse and Neglect Linkage (ALCANLink) project, a linkage of the 2009–2011 Alaska Pregnancy Risk Assessment Monitoring System survey and administrative data sources, and the 2012–2014 Childhood Understanding Behaviors Survey, we conducted latent class analysis to identify classes of AN/AI (N = 593) and non-Native (N = 1018) children in terms of seven risk factors (poverty, maternal depression, maternal binge drinking, parental incarceration, intimate partner violence exposure, other violence exposure, child maltreatment) and four protective factors (father figure involvement, reading by adults, family meals, peer interactions) experienced prior to age 3 years. We identified two classes among AN/AI children: (1) high risk-moderate protection (29.1%) and (2) low socioeconomic status-high protection (70.9%). We identified two classes among non-Native children: (1) moderate risk-high protection (32.9%) and (2) low risk-high protection (67.1%). A test of invariance revealed that risk and protective factor probabilities differed significantly for corresponding classes of AN/AI and non-Native children. Overall, results demonstrate heterogeneity within and between AN/AI and non-Native children in early experiences of risk and protection and suggest that interventions will be more effective if tailored to the experiences and developmental needs of specific groups of Alaska children

Trajectories of child protective services contact among Alaska Native/American Indian and non-Native children

Background: Contact with child protective services (CPS) functions as an independent marker of child vulnerability. Alaska children are an important population for understanding patterns of CPS contact given high rates of contact overall and among specific demographic groups. Objective: We aimed to identify longitudinal trajectory classes of CPS contact among Alaska Native/American Indian (AN/AI) and non-Native children and examine preconception and prenatal risk factors associated with identified classes. Participants and setting: We used data from the Alaska Longitudinal Child Abuse and Neglect Linkage (ALCANLink) project, a linkage of 2009–2011 Alaska Pregnancy Risk Assessment Monitoring System (PRAMS) births with administrative data including CPS records. Methods: We conducted growth mixture modeling to identify trajectory classes of CPS contact from birth to age five years. We used Vermunt's three-step approach to examine associations with preconception and prenatal risk factors. Results: Among AN/AI children, we identified three classes: 1) no/low CPS contact (75.4%); 2) continuous CPS contact (19.6%), and 3) early, decreasing CPS contact (5.0%). Among non-Native children, we identified four classes: 1) no CPS contact (81.3%); 2) low, increasing CPS contact (9.5%); 3) early, rapid decline CPS contact (5.8%); and 4) high, decreasing CPS contact (3.3%). Maternal substance use had the largest impact on probabilities of class membership, increasing the probability of membership in classes characterized by CPS contact, among both AN/AI and non-Native children. Conclusions: Results reveal heterogeneity in longitudinal patterns CPS contact across early childhood among Alaska children and identify maternal substance use as an important target for primary prevention