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The "structural disconnection" hypothesis of cognitive aging suggests that deterioration of white matter (WM), especially myelin, results in cognitive decline, yet in vivo evidence is inconclusive. We examined age differences in WM microstructure using Myelin Water Imaging and Diffusion Tensor Imaging in 141 healthy participants (age 20–79). We used the Virginia Cognitive Aging Project and the NIH Toolbox® to generate composites for memory, processing speed, and executive function. Voxel-wise analyses showed that lower myelin water fraction (MWF), predominantly in prefrontal WM, genu of the corpus callosum, and posterior limb of the internal capsule was associated with reduced memory performance after controlling for age, sex, and education. In structural equation modeling, MWF in the prefrontal white matter and genu of the corpus callosum significantly mediated the effect of age on memory, whereas fractional anisotropy (FA) did not. Our findings support the disconnection hypothesis, showing that myelin decline contributes to age-related memory loss and opens avenues for interventions targeting myelin health. • Myelin in prefrontal areas predicts memory performance. • Myelin, but not fractional anisotropy, mediates the age-memory relationship. • Myelin-cognition associations persist after adjusting for age. • Fractional anisotropy does not predict memory beyond age. [ABSTRACT FROM AUTHOR]

Social impairments are common across many psychiatric conditions. Standardized dyadic assessments intended to elicit social affiliation between unacquainted partners are used to elucidate mechanisms that disrupt relationship formation and inform possible treatment targets; however, the psychometric properties of such paradigms remain poorly understood. This study evaluated the psychometric properties of a controlled social affiliation paradigm intended to induce connectedness between a target participant and trained confederate. Individuals with an anxiety or depressive disorder diagnosis (clinical group; n = 132) and those without (control group; n = 35) interacted face-to-face with a trained confederate; partners took turns answering a series of increasingly intimate questions about themselves. Social connectedness, affect, and affiliative behavior measures were collected during the interaction. Participant symptom and social functioning measures were collected to examine validity. The paradigm elicited escalating social connectedness throughout the task for both participants and confederates. Parallel forms (i.e., different question sets) elicited similar affiliation outcomes. Self-reported (but not behavioral) affiliation differed across some demographic variables (e.g., participant gender, Hispanic ethnicity). Within-task affiliation measures were associated with one another and with global social connectedness and social anxiety symptom measures, but not with somatic anxiety measures. Clinical participants reported lower social affiliation and positive affect reactivity and higher negative affect reactivity than healthy participants. These findings provide initial psychometric support for a standardized and controlled dyadic affiliation paradigm that could be used to reliably probe social disconnection mechanisms across psychopathology. [ABSTRACT FROM AUTHOR]

Wisdom has gained increasing interest among researchers as a personality trait relevant to well-being and mental health. We previously reported development of a new 24-item San Diego Wisdom Scale (SD-WISE), with good to excellent psychometric properties, comprised of six subscales: pro-social behaviors, emotional regulation, self-reflection (insight), tolerance for divergent values (acceptance of uncertainty), decisiveness, and social advising. There is controversy about whether spirituality is a marker of wisdom. The present cross-sectional study sought to address that question by developing a new SD-WISE subscale of spirituality and examining its associations with various relevant measures. Data were collected from a national-level sample of 1,786 community-dwelling adults age 20–82 years, as part of an Amazon M-Turk cohort. Participants completed the 24-item SD-WISE along with several subscales of a commonly used Brief Multidimensional Measure of Religiousness/Spirituality, along with validated scales for well-being, resilience, happiness, depression, anxiety, loneliness, and social network. Using latent variable models, we developed a Spirituality subscale, which demonstrated acceptable psychometric properties including a unidimensional factor structure and good reliability. Spirituality correlated positively with age and was higher in women than in men. The expanded 28-item, 7-subscale SD-WISE total score (called the Jeste-Thomas Wisdom Index or JTWI) demonstrated acceptable psychometric properties. The Spirituality subscale was positively correlated with good mental health and well-being, and negatively correlated with poor mental health. However, compared to other components of wisdom, the Spirituality factor showed weaker (i.e., small-to-medium vs. medium-to-large) association with the SD-WISE higher-order Wisdom factor (JTWI). Similar to other components as well as overall wisdom, spirituality is significantly associated with better mental health and well-being, and may add to the predictive utility of the total wisdom score. Spirituality is, however, a weaker contributor to overall wisdom than components like pro-social behaviors and emotional regulation. Longitudinal studies of larger and more diverse samples are needed to explore mediation effects of these constructs on well-being and health. [ABSTRACT FROM AUTHOR]

Abstract Wisdom is an ancient concept that has gained new interest among clinical researchers as a complex trait relevant to well-being and healthy aging. As the empirical data regarding wisdom have grown, several measures have been used to assess an individual's level of wisdom. However, none of these measures has been based on a construct of wisdom with neurobiological underpinnings. We sought to develop a new scale, the San Diego Wisdom Scale (SD-WISE), which builds upon recent gains in the understanding of psychological and neurobiological models of the trait. Data were collected from 524 community-dwelling adults age 25–104 years as part of a structured multi-cohort study of adult lifespan. Participants were administered the SD-WISE along with two existing measures of wisdom that have been shown to have good psychometric properties. Factor analyses confirmed the hypothesized measurement model. SD-WISE total scores were reliable, demonstrated convergent and discriminant validity, and correlated, as hypothesized, negatively with emotional distress, but positively with well-being. However, the magnitudes of these associations were small, suggesting that the SD-WISE is not just a global measure of mental state. The results support the reliability and validity of SD-WISE scores. Study limitations are discussed. The SD-WISE, with good psychometric properties, a brief administration time, and a measurement model that is consistent with commonly cited content domains of wisdom based on a putative neurobiological model, may be useful in clinical practice as well as in bio-psycho-social research, especially investigations into the neurobiology of wisdom and experimental interventions to enhance wisdom. [ABSTRACT FROM AUTHOR]

We report detailed results of Arecibo and Goldstone radar observations of 30 mainbelt asteroids (MBAs) during 1980-1995. In addition to estimates of radar cross section, radar albedo, and circular polarization ratio, we obtain new constraints on pole direction for several asteroids, with those for 21 Lutetia being particularly restrictive. We carry out statistical analyses of disk-integrated properties (radar albedo and polarization ratio) of all 37 radar-observed MBAs. M asteroids seem to have higher radar albedos and a wider range of albedos than do asteroids from the other taxonomic classes; there is no evidence that C and S MBAs have different albedo distributions; and there is some suggestion, worthy of future study, that primitive B, F, G, and P asteroids are not as radar-bright as C and S objects. There is no statistically significant evidence that different taxonomic classes have different polarization ratio distributions, despite suggestions to the contrary based on visual inspection of these distributions. The similarity between the C and S albedo distributions implies similar near-surface regolith bulk densities. The hypothesis of ordinary chondritic composition for the S-class asteroids is reasonably consistent with the radar data, provided that these asteroids have typical lunar porosities. Nevertheless, it is possible that some of these targets have high-porosity regoliths of stony-iron composition. Our M-class sample presumably contains both metallic objects (such as 216 Kleopatra and, probably, 16 Psyche) and less metallic objects. Key Words: asteroids; radar.

Circadian rhythm disturbances, especially circadian phase delays are associated with impulsive behaviors and have been implicated in psychiatric disorders. Chronotype is a developmentally regulated proxy measure of circadian phase. Past studies have investigated the relationship between chronotype and trauma and found that trauma is associated with evening chronotypes, suggesting the course of chronotype development may be affected by adverse childhood experiences (ACEs). However, the relationships among chronotype, impulsivity and ACEs have largely been studied in a pairwise manner using small, cross-sectional cohorts. We hypothesized that in a cohort of high-risk youth, childhood trauma would be associated with later chronotype, and later chronotype would be associated with higher rates of impulsivity. We analyzed a cross-sectional sample (n = 966) from Year 2 of adolescents at high risk for psychiatric disorders from the ABCD study who were characterized for chronotype, stressful life events, and impulsivity. We used a hierarchical regression model to examine the relationship between chronotype, stressful life events, and impulsivity using the Munich Chronotype Questionnaire (MCTQ), the Life Events Scale, Urgency, Premeditation, Perseverance and Sensation Seeking (UPPS) Impulsive Behavior scale. We found associations between eveningness, stressful life events, and all dimensions of impulsivity. Increased eveningness was associated with a higher number of stressful life events and increased impulsivity. Understanding the role of stressful life events and impulsivity in those predisposed towards eveningness is useful because it may improve our understanding of the biological mechanisms that contribute to psychiatric disorders, and lead to better prevention and treatment efforts using interventions such as increased lifestyle regularity and daytime light exposure. • Impulsivity, later chronotype, stressful life events.→poor mental/physical health • Evening chronotype, stressful life events, and impulsivity are interrelated. • Investigation may help identify interventions to promote mental health & wellbeing. • Future work in prospective studies to clarify these factors will be essential. [ABSTRACT FROM AUTHOR]

We report Doppler-only (cw) and delay-Doppler radar observations of Bacchus obtained at Goldstone at a transmitter frequency of 8510 MHz (3.5 cm) on 1996 March 22, 24, and 29. Weighted, optimally filtered sums of cw and delay-Doppler echoes achieve signal-to-noise ratios of [approximately]80 and [approximately]25, respectively, and cover about 180 [degrees] of rotation phase (period = 14.90 h; Pravec et al. 1998). Our cw observations place up to four 2-Hz-resolution cells on Bacchus at echo powers greater than two standard deviations of the noise. Delay-Doppler observations typically place about ten 0.5-[[micro]seconds] (75-m) x 1-Hz cells on Bacchus above the same threshold. A weighted sum of ali cw spectra gives an OC radar cross section of [Mathematical Expression Omitted] and a circular polarization ratio of 0.21 [+ or -] 0.01. The dispersion of the echoes in time delay indicates a lower bound on Bacchus' maximum pole-on breadth of 0.6 km that is consistent with the echo bandwidth (6 [+ or -] 2 Hz) and rotation period. Echo spectra on March 22 and delay-Doppler images on all three days show a central deficit of echo power that provides strong evidence for a bifurcation in the shape. Inversion of delay-Doppler images, cw spectra, and optical lightcurves obtained at Ondrejov Observatory yields single-lobe and two-lobe models that define lower and upper bounds on the degree of bifurcation. Both shape models have a prominent central concavity, modestly asymmetric shapes, and similar physical dimensions, spin vectors, and radar and optical geometric albedos. We adopt the more conservative single-lobe shape model as our working model and explore its implications. It has a radar-derived sidereal rotation period [P.sub.sid] = 15.0 [+ or -] 0.2 h and a north pole within a few tens of degrees of ecliptic longitude [Lambda] = 24 [degrees] and ecliptic latitude [Beta] = -26 [degrees]; retrograde rotation is likely. It has dimensions of 1.11 x 0.53 x 0.50 km, an effective diameter (the diameter of a sphere with the same volume as the model) [Mathematical Expression Omitted], and radar and optical geometric albedos [Mathematical Expression Omitted] and [Mathematical Expression Omitted], respectively, that are larger than most estimated for other asteroids. Bacchus' low circular polarization ratio and high radar albedo are consistent with nearly regolith-free ordinary chondrite and basaltic achondrite compositions, but its high optical geometric albedo seems inconsistent with an ordinary chondrite composition and may favor a V-class composition. Bacchus has less structural complexity at centimeter-to-decimeter spatial scales and its near-surface is more dense (either more metal, lower porosity, or both) than the average radar-detected near-Earth asteroid. Key Words: asteroids; radar; Bacchus.

We report Doppler-only (cw) radar observations of near-Earth asteroid 1991 CS obtained at Goldstone at a transmitter frequency of 8510 MHz (3.5 cm) on 1996 August 26, 27, 28, and 29. Weighted, optimally filtered sums of cw echoes achieve signal-to-noise ratios in excess of 300 per day and thoroughly cover the asteroid in rotation phase (synodic period = 2.39 h, obtained photometrically by P. Pravec et al. 1998, Icarus 136, 124-153). A weighted sum of all cw spectra gives an OC radar cross section of 0.24 [+ or -] 0.08 [km.sup.2] and a circular polarization ratio of 0.28 [+ or -] 0.001. Our observations place up to 50 0.98-Hz resolution cells on 1991 CS at echo powers greater than 2 standard deviations of the noise. Variations of [approximately]10 Hz in the echo's 2-[Sigma] bandwidth are evident on each day and are consistent with the rotation period. Inversion of echo edge frequencies yields convex hulls of the pole-on silhouette for each day. The hulls have a mean elongation and rms dispersion of 1.18 [+ or -] 0.02 and place a lower bound on the maximum pole-on dimension of 1.3 km/cos [Delta], where [Delta] is the angle between the radar line-of-sight and the asteroid's apparent equator. The hulls suggest that 1991 CS has the least elongated pole-on silhouette of any of the nine near-Earth asteroids for which similar shape information from radar observations is available. If we assume that the projected area of 1991 CS is the same as that of a sphere with a diameter of 1.1 km, equal to the lower bound on the minimum breadth of the pole-on silhouette on August 28 and 29, then 1991 CS's radar cross section and absolute magnitude of 17.5 correspond to upper limits on the radar and optical geometric albedos of 0.25 and 0.14 that are consistent with its S-class taxonomy. The circular polarization ratio and radar albedo do not vary substantially as a function of rotation phase, suggesting that the near-surface of 1991 CS is relatively uniform. Among the 20 S-class asteroid radar detections previously reported, the circular polarization ratio of 1991 CS is greater than 11, comparable to 4, and less than 5. Key Words: asteroids; radar; 1991 CS.

We report initial results of daily delay/Doppler observations of Toutatis with the Goldstone 8510-MHz (3.5-cm) radar during Nov. 25-Dec. 3, 1996. Using the physical model of Toutatis derived from 1992 radar observations (Hudson and Ostro 1995, Science 270, 8486) to analyze the new data, we obtain refined estimates of the asteroid's orbit, spin state, and surface properties. The asteroid's centimeter-to-decameter surface characteristics are strikingly uniform. The disc-integrated circular polarization (SC/OC) ratio [[Mu].sub.C] averages 0.29 [+ or -] 0.01 and is independent of rotational orientation at the several percent level. Dual-polarization images reveal a slight drop in [[Mu].sub.C] at echo leading edges, which we interpret as the signature of a smooth surface component. The OC radar albedo averages 0.24 [+ or -] 0.03; it depends on rotational orientation, as expected from the asteroid's angular scattering behavior (limb-darkening slightly more than Lambertian). The OC albedo of a sphere with Toutatis' radar properties would be 0.21, or three times the lunar value. The radar properties and available nonradar constraints are consistent with Toutatis' surface having a smooth component that is at least 1/3 covered by rocks at least as large as the wavelength. If this S-class asteroid is mineralogically similar to stony-iron meteorites, then the smooth surface component probably is regolith whose porosity resembles that of lunar soil. If the mineralogy is ordinary chondritic, then the smooth surface component is probably solid with not much more than a centimeter of overlying regolith. We report delay-Doppler astrometry referenced to the asteroid's center of mass (COM) for each day of our experiment. An orbit solution that incorporates those measurements as well as the radar astrometry reported by Ostro et al. (1995, Science 270, 80-83) and 588 optical astrometric observations from 1988 through March 1997 has weighted rms residuals of 0.98 arcs, 0.10 Hz (1.8 mm [s.sup.-1] in radial velocity), and 0.49 [[micro]seconds] in time delay (73 m in range). Integration of that orbit into the past and future shows that Toutatis' pattern of close approaches to Venus, Earth, and Mars is highly asymmetric about the current epoch. The probability of the orbit intersecting Earth is zero for at least the next six centuries. Toutatis will make its closest planetary approach since at least 1353 and until at least 2562 on Sep. 29, 2004, when the closest COM-to-COM separation of Earth and Toutatis will be 1,549,834 [+ or -] 10 km (4.0 lunar distances). We use refined spin-state parameters and the 1995 shape model to generate 'movies' that predict the asteroid's rotational motion during its 2004 close approach, in geocentric and inertial frames. Key Words: asteroids; radar; Toutatis.

Abstract: When using functional brain imaging to study neuropsychiatric patients an important challenge is determining whether the imaging task assesses individual differences with equal precision in healthy control and impaired patient groups. Classical test theory (CTT) requires separate reliability studies of patients and controls to determine equivalent measurement precision with additional studies to determine measurement precision for different levels of disease severity. Unlike CTT, item response theory (IRT) provides estimates of measurement error for different levels of ability, without the need for separate studies, and can determine if different tests are equivalently difficult when investigating differential deficits between groups. To determine the potential value of IRT in functional brain imaging, IRT was applied to behavioral data obtained during a multi-center functional MRI (fMRI) study of working memory (WM). Average item difficulty was approximately one standard deviation below the ability scale mean, supporting the task''s sensitivity to individual differences within the ability range of patients with WM impairment, but not within the range of most controls. The correlation of IRT estimated ability with fMRI activation during the task recognition period supported the linkage of the latent IRT scale to brain activation data. IRT can meaningfully contribute to the design of fMRI tasks. [Copyright &y& Elsevier]

Perceived younger age is associated with positive health outcomes in existing literature. Few studies have examined these associations using a wide range of variables in large sample of adults of all ages. The objective of present study was to characterize the discrepancy between chronological age (CA) and subjective age (SA) in a large sample of community-dwelling adults across the lifespan, investigate associations with mental, physical, and cognitive health, and examine how it is related to a broad array of psychosocial variables relevant to well-being. Cross-sectional data from 1,004 individuals aged 21–100+ years from the Successful AGing Evaluation (SAGE) study were used for this analysis. Data included self-report measures of physical health (SF-36 – Physical Component), mental health composite score (created using CES-D Happiness scale, Satisfaction with Life Scale, SF-36 Mental Component, Brief Symptom Inventory Anxiety Scale, Patient Health Questionnaire-9, and Perceived Stress Scale), Telephone Interview for Cognitive Status - modified (TICS-m), and validated measures of various positive psychological variables such as meaning in life and optimism. On average, SA was 11.5 years younger than CA (SD 11.3). The discrepancy increased with CA. A younger SA compared to CA was associated with better mental and physical health in all age groups and was positively associated with measures of presence of meaning in life, successful aging, optimism, personal mastery, resilience, curiosity, hope, and social support. The association between age discrepancy and cognitive functioning was not statistically significant. These findings indicate that SA is potentially valuable for the purposes of clinical assessment and intervention, and this possibility should be investigated in future research. [ABSTRACT FROM AUTHOR]

Suicide is a serious public health problem, including among U.S. Army personnel. There is great interest in discovering objective predictors of suicide and non-fatal suicidal behaviors. The current study examined the association between neurocognitive functioning and pre-military history of suicide attempts (SA) and post-enlistment onset of SA. Methods: New Soldiers reporting for Basic Combat Training (N = 38,507) completed a comprehensive computerized neurocognitive assessment battery and self-report questionnaires. A subset of Soldiers (n = 6216) completed a follow-up survey, including assessment of lifetime SA, 3–7 years later. Six hundred eighty-nine Soldiers indicated lifetime SA at baseline and 210 Soldiers indicated new-onset SA at follow-up. Regression analyses, adjusted for demographic variables, revealed significant bivariate associations between neurocognitive performance on measures of sustained attention, impulsivity, working memory, and emotion recognition and lifetime SA at baseline. In a multivariable model including each of these measures as predictors, poorer impulse control and quicker response times on an emotion recognition measure were significantly and independently associated with increased odds of lifetime SA. A second model predicted new-onset SA at follow-up for Soldiers who did not indicate a history of SA at baseline. Poorer impulse control on a measure of sustained attention was predictive of new-onset SA. Limitations: Effect sizes are small and of unlikely clinical predictive utility. We simultaneously examined multiple neurocognitive domains as predictors of SA in a large, representative sample of new Army Soldiers. Impulsivity most strongly predicted past and future SA over and beyond other implicated cognitive-emotional domains. • Several cognitive-emotional domains predict lifetime suicide attempt in U.S. Soldiers. • Impulsivity is most strongly and uniquely related to pre-military suicide attempt in new Soldiers. • Poorer impulse control was also prospectively associated with new-onset suicide attempt. [ABSTRACT FROM AUTHOR]

Objective The assessment and remediation of boundary-challenged healthcare professionals is enhanced through examination of individual risk factors. We assessed three such factors--attachment style, childhood trauma and maladaptive beliefs--in 100 attendees (mostly physicians) of a CME professional boundaries course. We propose a theoretical model which draws a causal arc from childhood maltreatment through insecure attachment and maladaptive beliefs to elevated risk for boundary violations. Methods We administered the Experiences in Close Relationship Questionnaire (ECR-R), Childhood Trauma Questionnaire (CTQ), and Young Schema Questionnaire (YSQ) to 100 healthcare professionals (mostly physicians) attending a CME course on professional boundaries. Experts rated participant autobiographies to determine attachment style and early adversities. Correlations and relationships among self- and expert ratings and between different risk factors were examined. Results Five percent of participants reported CTQ total scores in the moderate to severe range; eleven percent reported moderate to severe emotional neglect or emotional abuse. Average attachment anxiety and attachment avoidance were low, and more than half of participants were rated “secure” by experts. Childhood maltreatment was correlated with attachment anxiety and avoidance and predicted expert-rated insecure attachment and maladaptive beliefs. Conclusion Our findings support a potential link between childhood adversity and boundary difficulties, partly mediated by insecure attachment and early maladaptive beliefs. Furthermore, these results suggest that boundary education programs and professional wellness programs may be enhanced with a focus on sequelae of childhood maltreatment, attachment and common maladaptive thinking patterns. [ABSTRACT FROM AUTHOR]