257 research outputs found
Seismic Response to Injection Well Stimulation in a High-Temperature, High-Permeability Reservoir
Fluid injection into the Earth's crust can induce seismic events that cause damage to local infrastructure but also offer valuable insight into seismogenesis. The factors that influence the magnitude, location, and number of induced events remain poorly understood but include injection flow rate and pressure as well as reservoir temperature and permeability. The relationship between injection parameters and injection-induced seismicity in high-temperature, high-permeability reservoirs has not been extensively studied. Here we focus on the Ngatamariki geothermal field in the central TaupĆ Volcanic Zone, New Zealand, where three stimulation/injection tests have occurred since 2012. We present a catalog of seismicity from 2012 to 2015 created using a matched-filter detection technique. We analyze the stress state in the reservoir during the injection tests from first motion-derived focal mechanisms, yielding an average direction of maximum horizontal compressive stress (SHmax) consistent with the regional NE-SW trend. However, there is significant variation in the direction of maximum compressive stress (Ï1), which may reflect geological differences between wells. We use the ratio of injection flow rate to overpressure, referred to as injectivity index, as a proxy for near-well permeability and compare changes in injectivity index to spatiotemporal characteristics of seismicity accompanying each test. Observed increases in injectivity index are generally poorly correlated with seismicity, suggesting that the locations of microearthquakes are not coincident with the zone of stimulation (i.e., increased permeability). Our findings augment a growing body of work suggesting that aseismic opening or slip, rather than seismic shear, is the active process driving well stimulation in many environments
Physical activity mediates the association between personality and biomarkers of inflammation
Objectives: The current study investigated whether personality traits and facets were associated with interleukin-6, C-reactive protein, and fibrinogen, and whether physical activity mediated the relationship between personality and biomarkers of inflammation. Methods: Personality was assessed in the Midlife Development in the United States study using the Multi-Dimensional Personality Questionnaire and Midlife Development Inventory personality scale. Data were included from 960 participants (mean age = 57.86 years, standard deviation = 11.46). Personality was assessed from 2004 to 2009. Serum levels of interleukin-6, fibrinogen, and C-reactive protein were assessed in 2005â2009 as part of the Midlife Development in the United States biomarkers subproject. Results: Lower neuroticism was associated with elevated interleukin-6, and achievement was associated with lower fibrinogen. Higher physical activity was associated with lower interleukin-6 and C-reactive protein. Mediation models suggested that physical activity mediated the associations between achievement and both interleukin-6 and C-reactive protein. Discussion: Physical activity is an important factor in the Health Behavior Model of personality and explains some of the associations between personality and inflammation. These findings contribute to the fields of aging and health by linking individual difference factors to markers of inflammation, and showing that these processes may function partially through specific behaviors, in this case physical activity
Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015).
BACKGROUND: Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (NâŻ=âŻ1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB.
METHODS: Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (nâŻ=âŻ251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; nâŻ=âŻ315), and the Early Growth and Development Study (NâŻ=âŻ625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (nâŻ=âŻ654) and female (nâŻ=âŻ537) infants, separately.
RESULTS: Mean birth weight and length of gestation were 3277âŻg (SDâŻ=âŻ543) and 37.8âŻweeks (SDâŻ=âŻ2.0), respectively. Rates of prenatal use were as follows: any use, nâŻ=âŻ748 (62.8%); MJ use, nâŻ=âŻ273 (22.9%); TOB use, nâŻ=âŻ608 (51.0%); co-use of MJ and TOB, nâŻ=âŻ230 (19.3%); ALC use, nâŻ=âŻ464 (39.0%); and OTH use nâŻ=âŻ115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE)âŻ=âŻ-84.367(38.271), 95% C.I. -159.453 to -9.281, pâŻ=âŻ.028], any TOB use [B(SE)âŻ=âŻ-0.99.416(34.418), 95% C.I. -166.942 to -31.889, pâŻ=âŻ.004], and each cigarette/day in mean TOB use [B(SE)âŻ=âŻ-12.233(3.427), 95% C.I. -18.995 to -5.510, pâŻ\u3câŻ.001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE)âŻ=âŻ-153.1 (54.20); 95% C.I. -259.5 to -46.7, pâŻ=âŻ.005], but not female infants [B(SE)âŻ=âŻ8.3(53.1), 95% C.I. -96.024 to 112.551, pâŻ=âŻ.876]. TOB, MJ, and their co-use were not associated with length of gestation.
CONCLUSIONS: In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes
Variability Modifies Life Satisfaction\u27s Association With Mortality Risk In Older Adults
Greater life satisfaction is associated with greater longevity, but its variability across time has not been examined relative to longevity. We investigated whether mean life satisfaction across time, variability in life satisfaction across time, and their interaction were associated with mortality over 9 years of follow-up. Participants were 4,458 Australians initially at least 50 years old. During the follow-up, 546 people died. After we adjusted for age, greater mean life satisfaction was associated with a reduction in mortality risk, and greater variability in life satisfaction was associated with an increase in mortality risk. These findings were qualified by a significant interaction such that individuals with low mean satisfaction and high variability in satisfaction had the greatest risk of mortality over the follow-up period. In combination with mean life satisfaction, variability in life satisfaction is relevant for mortality risk among older adults. Considering intraindividual variability provides additional insight into associations between psychological characteristics and health
Non-commutative flux representation for loop quantum gravity
The Hilbert space of loop quantum gravity is usually described in terms of
cylindrical functionals of the gauge connection, the electric fluxes acting as
non-commuting derivation operators. It has long been believed that this
non-commutativity prevents a dual flux (or triad) representation of loop
quantum gravity to exist. We show here, instead, that such a representation can
be explicitly defined, by means of a non-commutative Fourier transform defined
on the loop gravity state space. In this dual representation, flux operators
act by *-multiplication and holonomy operators act by translation. We describe
the gauge invariant dual states and discuss their geometrical meaning. Finally,
we apply the construction to the simpler case of a U(1) gauge group and compare
the resulting flux representation with the triad representation used in loop
quantum cosmology.Comment: 12 pages, matches published versio
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Do Cherished Children Age Successfully? Longitudinal Findings From the Veterans Affairs Normative Aging Study
Although early adversity has been linked to worse mental and physical health in adulthood, few studies have investigated the pathways through which positive and negative dimensions of early experiences can jointly influence psychological well-being in later life. This study examined: (a) profiles of early experiences across multiple domains, (b) the relations of these profiles to hedonic and eudaimonic well-being in later life, and (c) whether midlife social support mediated these relations. We first conducted latent class analysis of early experiences using data from 1,076 men in the VA Normative Aging Study who completed the Childhood Experiences Scale (age: M = 69, SD = 7). Analyses yielded 3 profiles of early experiences, labeled as cherished (strong support and some losses), harshly disciplined (harsh parental discipline, low positive reinforcement, and nonnormative stressors), and ordinary (few stressors and low parental attention). Next, we applied structural equation modeling to data on a subset of this sample assessed 7 years later on hedonic and eudaimonic well-being (n = 496; age: M = 76, SD = 7). In general, the cherished group reported stronger qualitative social support in midlife than the harshly disciplined and ordinary groups, which in turn was related to greater hedonic (life satisfaction, positive affect) and eudaimonic (competence, positive relations with others) well-being in later life. The cherished group also reported higher autonomy than the ordinary group, but this association was independent of midlife social support. Our findings suggest that experiencing adversity in the context of a nurturing early environment can promote successful aging through the maintenance of supportive relationships in midlife.This is the publisherâs final pdf. The published article is copyrighted by the American Psychological Association and can be found at: http://dx.doi.org/10.1037/pag0000050
This article may not exactly replicate the final version published in the APA journal. It is not the copy of record.Keywords: early adversity, latent class analysis, eudaimonic well-being, successful aging, hedonic well-bein
Who settles for less? Subjective dispositions, objective circumstances, and housing satisfaction
In recent years there has been growing interest in individualsâ self-perceptions of their wellbeing on the grounds that these complement well-established objective indicators of welfare. However, individualsâ assessments depend on both objective circumstances and subjective, idiosyncratic dispositions, such as aspirations and expectations. We add to the literature by formulating a modelling strategy that uncovers how these subjective dispositions differ across socio-demographic groups. This is then tested using housing satisfaction data from a large-scale household panel survey from Australia. We find that there are significant differences in the way in which individuals with different characteristics rate the same objective reality. For instance, male, older, migrant, and Indigenous individuals rate equal housing conditions more favourably than female, younger, Australian-born, and non-Indigenous individuals. These findings have important implications for how self-reported housing satisfaction, and wellbeing data in general, are to be used to inform evidence-based policy
Background Independent Quantum Gravity: A Status Report
The goal of this article is to present an introduction to loop quantum
gravity -a background independent, non-perturbative approach to the problem of
unification of general relativity and quantum physics, based on a quantum
theory of geometry. Our presentation is pedagogical. Thus, in addition to
providing a bird's eye view of the present status of the subject, the article
should also serve as a vehicle to enter the field and explore it in detail. To
aid non-experts, very little is assumed beyond elements of general relativity,
gauge theories and quantum field theory. While the article is essentially
self-contained, the emphasis is on communicating the underlying ideas and the
significance of results rather than on presenting systematic derivations and
detailed proofs. (These can be found in the listed references.) The subject can
be approached in different ways. We have chosen one which is deeply rooted in
well established physics and also has sufficient mathematical precision to
ensure that there are no hidden infinities. In order to keep the article to a
reasonable size, and to avoid overwhelming non-experts, we have had to leave
out several interesting topics, results and viewpoints; this is meant to be an
introduction to the subject rather than an exhaustive review of it.Comment: 125 pages, 5 figures (eps format), the final version published in CQ
Trajectories of Big Five Personality Traits: A Coordinated Analysis of 16 Longitudinal Samples
This study assessed change in selfâreported Big Five personality traits. We conducted a coordinated integrative data analysis using data from 16 longitudinal samples, comprising a total sample of over 60 000 participants. We coordinated models across multiple datasets and fit identical multiâlevel growth models to assess and compare the extent of trait change over time. Quadratic change was assessed in a subset of samples with four or more measurement occasions. Across studies, the linear trajectory models revealed declines in conscientiousness, extraversion, and openness. Nonâlinear models suggested lateâlife increases in neuroticism. Metaâanalytic summaries indicated that the fixed effects of personality change are somewhat heterogeneous and that the variability in trait change is partially explained by sample age, country of origin, and personality measurement method. We also found mixed evidence for predictors of change, specifically for sex and baseline age. This study demonstrates the importance of coordinated conceptual replications for accelerating the accumulation of robust and reliable findings in the lifespan developmental psychological sciences. © 2020 European Association of Personality PsychologyPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/1/per2259.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/2/per2259-sup-0001-Data_S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/3/per2259-sup-0002-Open_Practices_Disclosure_Form.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/4/per2259_am.pd
Personality Predicts Mortality Risk: An Integrative Data Analysis of 15 International Longitudinal Studies
This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR<1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research.Funding support for this project was provided by the National Institute on Aging: P01-AG043362 (Integrative Analysis of Longitudinal Studies of Aging (IALSA), [Scott M. Hofer (PI)]), and Daniel K. Mroczek (CoInvestigator
and Project Leader of the IALSA Personality & Health
Project, as well as R01-AG018436 [Personality & Well-Being Trajectories in Adulthood, Daniel K. Mroczek, PI])
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