The depths of despair among US adults entering midlife

Objectives. To test whether indicators of despair are rising among US adults as they age toward midlife and whether this rise is concentrated among low-educated Whites and in rural areas. Methods. We used data from the National Longitudinal Study of Adolescent to Adult Health, a nationally representative study of US adolescents in 1994. Our sample was restricted to individuals who participated in 1 or more of 5 waves (1994-2017) and self-identified as non-Hispanic White, non-Hispanic Black, or Hispanic (n = 18 446).We examined change in indicators of despair from adolescence to adulthood using multilevel regression analysis, testing for differences by race/ethnicity, education, and rurality. Results. We found evidence of rising despair among this cohort over the past decade. This increase was not restricted to low-educated Whites or to rural areas. Conclusions. Results suggest that generally rising despair among the young adult cohort now reaching midlife that cuts across racial/ethnic, educational, and geographic groups may presage rising midlife mortality for these subgroups in the next decade

Race/Ethnicity, Gender, and Trajectories of Depressive Symptoms Across Early- and Mid-Life Among the Add Health Cohort

While disparities in depressive symptoms by race/ethnicity and gender have been documented, left unclear is how such status characteristics intersect to influence mental health, particularly across early life and among a diverse set of population subgroups. This study investigates how intra- and inter-individual trends in depressive symptoms unfold across a 30-year span (ages 12–42) and are structured by the intersection of race/ethnicity and gender among White, Black, Hispanic, and Asian American young adults (N = 18,566). Analyses use data from the National Longitudinal Study of Adolescent to Adult Health, a nationally representative study of adolescents who have been followed through their fourth decade of life. We draw on Waves I–IV and a representative subsample of the brand new Wave V data. Growth curve models indicated depressive symptoms decreased across adolescence and young adulthood before increasing in the early 30s. Racial/ethnic minorities reported more depressive symptoms than Whites. Women reported more depressive symptoms than men and experienced especially steep increases in their late 30s. Racial/ethnic-gender disparities remained stable with age, except for Hispanic-White disparities among women and Asian American-White disparities among men, which narrowed with age. Overall, findings demonstrate dynamic inequalities across a longer period of the life span than was previously known, as well as heterogeneity in trajectories of poor mental health within and between racial/ethnic-gender groups. Results also suggest that Black and Asian American women experience the highest mental health risks and that interventions for reducing disparities in depressive symptoms should focus on adults in their late 20s/early 30s, particularly women of color

Analytic theory of the Rayleigh-Taylor instability in a uniform density plasma-filled ion diode

The J-vector x B-vector forces associated with the surface current of a plasma-filled ion diode will accelerate this plasma fill toward the anode surface. It is well known that such a configuration with a high I is susceptible to the hydromagnetic Rayleigh-Taylor instability in certain geometries. A number of ion diode plasma sources have been proposed, most of which have a falling density going away from the wall. A somewhat more unstable case, however, is that of uniform density. In this report we attempt to establish an upper limit on this effect with a simple analytic model in which a uniform-density plasma is accelerated by the magnetic field anticipated in a PBFA-II diode. We estimate the number of linear e-foldings experienced by an unstable surface as well as the most damaging wavelength initial perturbation. This model, which accounts approximately for stabilization due to field diffusion, suggests that even with a uniform fill, densities in excess of a few 10/sup 15/ are probably not damaged by the instability. In addition, even lower densities might be tolerated if perturbations near the most damaging wavelength can be kept very small

THE SANDIA X-RAY LASER PROGRAM

Le laser au rayon X en train d'être développé aux Laboratoires Sandia utilise un rayonnement keV intense, produit par la compression cylindrique ("Z-pinch") d'une bouffée de gaz, pour obtenir les ions de la série isoélectronique F par la photoionisation des ions Ne. Les populations des niveaux de la configuration (2p)5(3p) et de la configuration (2p)5(3s) sont inverties par des processus de recombinaison des ions. Une enveloppe annulaire de stagnation maintient la séparation entre la source du rayonnement et le plasma étant lasé. Une couche mince d'aluminium ou sodium sert pour changer la longueur d'onde du rayonnement. La méthode pour arriver aux dimensions et à la densité du laser au rayon X est décrite.The Sandia X-ray Laser Program is based on the use of intense keV radiation produced by gas puff, Z-pinch implosions to photoionize Ne-like ions to F-like ions. A 3p-3s population inversion is generated via recombination processes. An annular stagnation shell is used to separate the imploding pump source from the lasant. We are also developing a converter technology for examining the Na-Ne line matching scheme. Design considerations and some computational results are presented

Z-PINCH IMPLOSION DRIVEN X-RAY LASER RESEARCH

In experiments performed during the past two years on Proto II (a 10-TW pulsed-power accelerator), we imploded annular plasmas onto thin-walled annular x-ray laser targets in order to create a radiation pump source for x-ray laser physics studies. This Z-pinch must be axially uniform and must efficiently produce the pump radiation without destroying the laser medium on the cylindrical axis of symmetry. To characterize the pump source x-rays and lasant conditions, we regularly field a large number of x-ray diagnostics. In recent experiments, we produced over 15 kJ of ≥1-keV pump radiation with an imploding neon gas-puff load. We are considering both recombination and resonance-pumped x-ray laser schemes

Negative in-plane and out-of-plane magnetoresistivities in optimally doped Bi2Sr2Ca0.8Y0.2Cu2O8+d single crystal

Both the in-plane and out-of-plane magnetoresistivities have been measured in the normal state of an optimally doped Bi2Sr2Ca0.8Y0.2Cu2O8+d single crystal with a magnetic field applied parallel and perpendicular to the CuO2 planes. Whatever the magnetic field and the current directions are, a negative magnetoresistivity is obtained over a wide range of temperature above the critical temperature Tc. For the in-plane and out-of-plane measurements, the non-dominant orbital contribution to magnetoresistivity suggests the substantial role played by the spin degrees of freedom.Comment: 4 pages, 3 figures accepted for publication in Physical Revue

Trends in the detection of aquatic non-indigenous species across global marine, estuarine and freshwater ecosystems: a 50-year perspective

Aim The introduction of aquatic non-indigenous species (ANS) has become a major driver for global changes in species biogeography. We examined spatial patterns and temporal trends of ANS detections since 1965 to inform conservation policy and management. Location Global. Methods We assembled an extensive dataset of first records of detection of ANS (1965–2015) across 49 aquatic ecosystems, including the (a) year of first collection, (b) population status and (c) potential pathway(s) of introduction. Data were analysed at global and regional levels to assess patterns of detection rate, richness and transport pathways. Results An annual mean of 43 (±16 SD) primary detections of ANS occurred—one new detection every 8.4 days for 50 years. The global rate of detections was relatively stable during 1965–1995, but increased rapidly after this time, peaking at roughly 66 primary detections per year during 2005–2010 and then declining marginally. Detection rates were variable within and across regions through time. Arthropods, molluscs and fishes were the most frequently reported ANS. Most ANS were likely introduced as stowaways in ships’ ballast water or biofouling, although direct evidence is typically absent. Main conclusions This synthesis highlights the magnitude of recent ANS detections, yet almost certainly represents an underestimate as many ANS go unreported due to limited search effort and diminishing taxonomic expertise. Temporal rates of detection are also confounded by reporting lags, likely contributing to the lower detection rate observed in recent years. There is a critical need to implement standardized, repeated methods across regions and taxa to improve the quality of global-scale comparisons and sustain core measures over longer time-scales. It will be fundamental to fill in knowledge gaps given that invasion data representing broad regions of the world's oceans are not yet readily available and to maintain knowledge pipelines for adaptive management