Light bending and X-ray echoes from behind a supermassive black hole.

The innermost regions of accretion disks around black holes are strongly irradiated by X-rays that are emitted from a highly variable, compact corona, in the immediate vicinity of the black hole1-3. The X-rays that are seen reflected from the disk4, and the time delays, as variations in the X-ray emission echo or 'reverberate' off the disk5,6, provide a view of the environment just outside the event horizon. I Zwicky 1 (I Zw 1) is a nearby narrow-line Seyfert 1 galaxy7,8. Previous studies of the reverberation of X-rays from its accretion disk revealed that the corona is composed of two components: an extended, slowly varying component extending over the surface of the inner accretion disk, and a collimated core, with luminosity fluctuations propagating upwards from its base, which dominates the more rapid variability9,10. Here we report observations of X-ray flares emitted from around the supermassive black hole in I Zw 1. X-ray reflection from the accretion disk is detected through a relativistically broadened iron K line and Compton hump in the X-ray emission spectrum. Analysis of the X-ray flares reveals short flashes of photons consistent with the re-emergence of emission from behind the black hole. The energy shifts of these photons identify their origins from different parts of the disk11,12. These are photons that reverberate off the far side of the disk, and are bent around the black hole and magnified by the strong gravitational field. Observing photons bent around the black hole confirms a key prediction of general relativity.

Associations of changes in fat free mass with risk for type 2 diabetes: Hispanic Community Health Study/Study of Latinos.

AIMS: To determine whether loss of muscle mass (approximated using fat free mass [FFM]) is associated with risk for type 2 diabetes mellitus (T2DM) in Hispanic/Latino adults in the United States. METHODS: Participants were Hispanic/Latino adults (18-74-year-olds) who completed Visit 2 of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL; multi-site, prospective cohort study; 6.1-year follow-up) and did not have T2DM at baseline (n = 6264). At baseline and Visit 2, FFM was measured using bioelectrical impedance analysis and fasting glucose, HbA1c, and fasting insulin were measured by examiners. Diabetes was defined according to American Diabetes Association criteria. Survey-weighted Poisson regression models examined the association of percent change in relative FFM (%ΔFFM) with incident prediabetes and T2DM. Survey-weighted multivariable regression models examined associations of %ΔFFM with changes in glucose and insulin measures. RESULTS: Relative FFM declined by 2.1% between visits. %ΔFFM was inversely associated with incident prediabetes (p-for-trend = 0.001) and with changes in glucose and insulin measures (p-for-trend <0.0001). Findings were null, except for HOMA-IR, after adjustment for changes in adiposity measures. Associations were generally stronger for individuals with baseline overweight/obesity. CONCLUSIONS: Reducing loss of FFM during adulthood may reduce prediabetes risk (primarily insulin resistance), particularly among individuals with overweight/obesity.

Family function and eating behaviours among Hispanic/Latino youth: results from the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth).

OBJECTIVE: To elucidate mechanisms across family function, home environment and eating behaviours within sociocultural context among Hispanic youth. DESIGN: Two models tested via path analysis (youth fruit and vegetable (FV) consumption; empty energy consumption) using data from the Study of Latino Youth (2011-2013). SETTING: Chicago, IL; Miami, FL; Bronx, NY; San Diego, CA. PARTICIPANTS: Youth (8-16-year-olds), n 1466. RESULTS: Youth ate 2·4 servings of FV per d and received 27 % of total energy from empty energies. Perceiving higher acculturative stress was indirectly associated with lower FV consumption via a pathway of low family function and family support for FV (ß = -0·013, P < 0·001) and via lower family closeness and family support (ß = -0·004, P = 0·004). Being >12-year-olds was indirectly associated with lower FV consumption via lower family closeness and family support (ß = -0·006, P < 0·001). Household food security was indirectly associated with greater FV consumption via family closeness and family support (ß = 0·005, P = 0·003). In contrast, perceiving higher acculturative stress was indirectly associated with higher empty energy consumption (via family closeness and family support: ß = 0·003, P = 0·028 and via low family function and low family support: ß = 0·008, P = 0·05). Being older was associated with higher consumption of empty energies via family closeness (related to family support: ß = 0·04, P = 0·016; parenting strategies for eating: ß = 0·002, P = 0·049). CONCLUSIONS: Findings suggest pathways of influence across demographic and sociocultural context, family dynamics and home environment. The directionality of these associations needs confirmation using longitudinal data.

Trait anger, cynical hostility and inflammation in Latinas: variations by anger type?

Anger and hostility are psychological factors that appear to play a salient role in relation to cardiovascular disease (CVD) risk; however, their association with risk within the Latino population remains relatively unexplored. The current study examined associations between overall trait anger, anger subdimensions (i.e., anger temperament and anger reaction) and cynical hostility with sICAM-1, a marker of cellular adhesion and systemic inflammation related to CVD risk, in a sample of 294 middleaged Mexican-American women. Results showed no association between trait anger or anger temperament and sICAM-1. Anger reaction was marginally associated with sICAM-1 (ß=4.77, p=.06). Cynical hostility was significantly associated with sICAM-1 (ß=5.89, p=.04) even after controlling for demographic, biological and behavioral covariates. The current study provides evidence that specific aspects of anger and hostility relate to physiological pathways that potentially influence CVD risk. Findings are discussed in light of contextual cultural factors.

Broad line emission from iron K- and L-shell transitions in the active galaxy 1H 0707-495.

Since the 1995 discovery of the broad iron K-line emission from the Seyfert galaxy MCG-6-30-15 (ref. 1), broad iron K lines have been found in emission from several other Seyfert galaxies, from accreting stellar-mass black holes and even from accreting neutron stars. The iron K line is prominent in the reflection spectrum created by the hard-X-ray continuum irradiating dense accreting matter. Relativistic distortion of the line makes it sensitive to the strong gravity and spin of the black hole. The accompanying iron L-line emission should be detectable when the iron abundance is high. Here we report the presence of both iron K and iron L emission in the spectrum of the narrow-line Seyfert 1 galaxy 1H 0707-495. The bright iron L emission has enabled us to detect a reverberation lag of about 30 s between the direct X-ray continuum and its reflection from matter falling into the black hole. The observed reverberation timescale is comparable to the light-crossing time of the innermost radii around a supermassive black hole. The combination of spectral and timing data on 1H 0707-495 provides strong evidence that we are witnessing emission from matter within a gravitational radius, or a fraction of a light minute, from the event horizon of a rapidly spinning, massive black hole.

Educational attainment and coronary and aortic calcification in postmenopausal women.

OBJECTIVE: Low socioeconomic status is a risk factor for clinical coronary heart disease, a relatively crude outcome associated with important biases. By avoiding these biases, subclinical assessments could facilitate efforts to understand the association between socioeconomic status and coronary disease. The current study 1) evaluated the nature of the associations between educational attainment and subclinical atherosclerosis and 2) examined if biologic, behavioral, and psychosocial factors mediated these associations. METHODS: Participants were 308 women from the Healthy Women Study who underwent a clinic examination of risk factors either 5 (N = 32) or 8 (N = 276) years after the menopausal transition. Aortic and coronary calcification were measured using electron beam tomography. RESULTS: Logistic regression analysis with orthogonal polynomials revealed a marginally significant linear trend for coronary calcification, with the more educated groups showing lower calcification than the less educated groups. A significant linear trend was also observed for aortic calcification. In addition, a marginally significant quadratic trend was observed for aortic calcification so that the effect began to reverse at the highest level of education. Measured risk factors were associated with education and with the calcification outcomes, but they explained little of the associations between educational attainment and coronary or aortic calcification. None of the factors tested met the minimum criterion for mediation. CONCLUSIONS: The findings show that lower education is associated with greater early stage atherosclerosis. Subclinical assessments, such as electron beam tomography, represent useful alternatives for studies of socioeconomic status and coronary artery disease.

Cardiovascular and electrodermal responses to support and provocation: interpersonal methods in the study of psychophysiological reactivity.

This study examined the joint and independent effects of experimentally manipulated social contexts and individual differences in hostility and perceived social support on physiological responses to a social stressor, while illustrating the use of the interpersonal circumplex for integrative social psychophysiological research. Undergraduate women completed a speech task in a supportive, neutral, or provoking context and completed measures of hostility and perceived social support. The provoking context evoked the largest blood pressure and heart rate (HR) responses, followed by the neutral and the supportive context. Social context also influenced HR and electrodermal reactivity during task preparation. Hostility elicited higher systolic blood pressure (SBP) reactivity during preparation, speech, and recovery. Perceived social support interacted with context to affect SBP and HR during speech and preparation. The roles of interpersonal characteristics and contexts in the physiological stress response and the utility of interpersonal methods in studying these associations are discussed.

Hostility and cardiovascular reactivity during marital interaction.

OBJECTIVE: Prior studies demonstrate that hostile persons respond to social stressors with heightened cardiovascular responses. This study examined the effects of individual differences in hostility and two experimentally manipulated social stressors on cardiovascular reactivity during marital interaction. METHODS: Sixty couples participated in a discussion task under conditions of high or low evaluative threat and while either agreeing or disagreeing with each other. Individual differences in hostility were assessed with the Buss-Perry Aggression Questionnaire. Participants' appraisal of their spouses' behavior during the interaction task was assessed with a standardized measure. Systolic and diastolic blood pressure and heart rate responses were recorded. RESULTS: Among husbands, hostility was associated with greater systolic blood pressure reactivity under high, but not low, threat. Appraisals suggested that this might be due to husbands' efforts to assert dominance in the interaction. Wives' hostility scores were unrelated to cardiovascular reactivity, but wives disagreeing with hostile husbands showed greater heart rate reactivity. CONCLUSIONS: Heightened cardiovascular reactivity to stressful marital interactions among hostile men provides additional evidence of the viability of this psychophysiologic mechanism as a link between hostility and health. The lack of effects among wives suggests sex differences in the social psychophysiology of hostility. Interpersonal concepts and methods are useful in the study of psychosocial risk factors and mechanisms.

Do negative emotions mediate the association between socioeconomic status and health?

In this chapter, we examine the possibility that negative emotions contribute to the relationship between socioeconomic status (SES) and health. A model of the associations among SES, emotion, and health is presented first. We then review the evidence for this model, showing associations of SES with depression, hopelessness, anxiety, and hostile affect and cognition, and of these negative emotions with disease. Notably, most of the data supporting the model provide only indirect evidence that negative emotions serve as a key contributor to the proposed associations. We, therefore, conclude with recommendations for longitudinal research, especially in children, that will more directly and comprehensively examine negative emotions as possible mediators of the SES and health relationship.

Agency, communion, and cardiovascular reactivity during marital interaction.

The concepts of agency and communion have been used to describe sex differences in vulnerability to specific stressor domains. This study examined blood pressure and heart rate responses of 60 married couples to experimental manipulations of disagreement (i.e., communion stressor) and achievement challenge (i.e., agency stressor). Consistent with predictions, disagreement elicited heightened cardiovascular reactivity among wives, but not husbands. In contrast, the achievement challenge elicited heightened cardiovascular reactivity among husbands, but not wives. Participants' responses to a circumplex measure of interpersonal appraisal were consistent with the interpretation of differential responses to agency and communion stressors. Results are congruent with a situational approach to sex differences in cardiovascular reactivity and illustrate the utility of interpersonal methods in the explication of psychosocial risk for cardiovascular disease.

Construct validation of health-relevant personality traits: interpersonal circumplex and five-factor model analyses of the Aggression Questionnaire.

The general literature on personality traits as risk factors for physical illness--as well as the specific literature on health consequences of anger, hostility, and aggressive behavior--often suffers from incomplete or inconsistent construct validation of personality measures. This study illustrates the utility of two conceptual tools in this regard--the five-factor model and the interpersonal circumplex. The similarities and differences among anger, hostility, verbal aggressiveness, and physical aggressiveness as measured by the Buss and Perry (1992) Aggression Questionnaire were identified. Results support the interpretation of anger and hostility as primarily reflecting neurotic hostility and antagonistic hostility to a lesser extent. In contrast, verbal and physical aggressiveness can he seen as primarily reflecting antagonistic hostility, and to a lesser extent neurotic hostility. Further, verbal aggressiveness was associated with hostile dominance, whereas hostility was associated with hostile submissiveness. These findings identify potentially important distinctions among these related constructs and illustrate the potential integrative value of standard validation procedures.

Interpersonal control and cardiovascular reactivity: goals, behavioral expression, and the moderating effects of sex.

Cardiovascular responses to stressful stimuli have been implicated in the development of cardiovascular disease. However, the effects of social stressors on short-term changes in blood pressure and heart rate (i.e., cardiovascular reactivity [CVR]) are not well understood. The independent effects of an incentive to exert interpersonal influence and the expression of socially controlling behavior on CVR were examined in 96 undergraduates. For men, both the incentive to exert influence and the enactment of a controlling interpersonal style produced larger increases in systolic blood pressure. By contrast, although the incentive to be influential increased women's CVR, the enactment of a cooperative role produced the largest increases in blood pressure among women. The effects of social dominance on CVR, sex differences in CVR, and interpersonal approaches to the study of these psychophysiological mechanisms are discussed.

The circadian rhythm of temperature during light treatment for winter depression.

Circadian rhythm abnormalities have been implicated in winter seasonal affective disorder. We examined the circadian temperature rhythm of 22 patients with winter depression and 10 normal controls who had participated in various high-intensity light treatment experiments. We did not find abnormalities in the baseline phase or amplitude of the temperature rhythm in patients compared to controls. Nor did we find abnormalities in the phase-shifting response to morning light. There was some evidence that the "phase-delayed" half of the patients responded poorly to phase advances produced by morning light, whereas the "phase-advanced" half of the patients responded poorly when their rhythms delayed. However, the antidepressant responses during the best week (week of lowest depression score) were unrelated to temperature rhythm phase shifts. In general, there was not strong support for a relationship between circadian rhythms changes and antidepressant response.

Circadian rhythms during gradually delaying and advancing sleep and light schedules.

The circadian rhythms of the night shift worker show very little phase shift in response to the daytime sleep and night work schedule. One strategy for producing circadian adaptation may be to use appropriately timed exposure to high-intensity light. We attempted to shift the circadian temperature rhythms of seven normal subjects while they followed a sleep schedule that gradually delayed (2 h per day) until sleep occurred during the daytime, as is customary for workers during the night shift. After 5 days, the sleep schedule was gradually advanced back to baseline. High illuminance light (2 h per day) and the attenuation or avoidance of sunlight were timed to facilitate temperature rhythm phase shifts. In general, the temperature rhythm did not shift along with the sleep-wake schedule, but appeared either to free run or remain entrained to the natural 24-h zeitgebers. This study showed how difficult it can be to shift human circadian rhythms in the field, when subjects are exposed to competing 24-hr zeitgebers.