4,783 research outputs found
Factorial Invariance of the Brief Symptom Inventory-18 (BSI-18) for Adults of Mexican Descent across Nativity Status, Language Format, and Gender
The cultural equivalence of psychological outcome measures remains a major area of investigation. The current study sought to test the factor structure and factorial invariance of the Brief Symptom Inventory-18 (BSI-18) with a sample of adult individuals of Mexican descent (N = 923) across nativity status (U.S.- vs. foreign-born), language format (English vs. Spanish), and gender. The results show that 1-factor and 3-factor measurement models provided a good fit to the data; however, a single-factor model was deemed more appropriate and parsimonious. Tests of measurement invariance and invariance of factor variances (i.e., structural invariance) indicated at least partial measurement invariance across gender, nativity status, and language format. These findings suggest that the BSI-18 operates in a similar fashion among adults of Mexican descent regardless of nativity status, language format of the survey, and gender. Clinical and practical implications for use of the BSI-18 with Latino populations are discussed
The use of multilayer network analysis in animal behaviour
Network analysis has driven key developments in research on animal behaviour
by providing quantitative methods to study the social structures of animal
groups and populations. A recent formalism, known as \emph{multilayer network
analysis}, has advanced the study of multifaceted networked systems in many
disciplines. It offers novel ways to study and quantify animal behaviour as
connected 'layers' of interactions. In this article, we review common questions
in animal behaviour that can be studied using a multilayer approach, and we
link these questions to specific analyses. We outline the types of behavioural
data and questions that may be suitable to study using multilayer network
analysis. We detail several multilayer methods, which can provide new insights
into questions about animal sociality at individual, group, population, and
evolutionary levels of organisation. We give examples for how to implement
multilayer methods to demonstrate how taking a multilayer approach can alter
inferences about social structure and the positions of individuals within such
a structure. Finally, we discuss caveats to undertaking multilayer network
analysis in the study of animal social networks, and we call attention to
methodological challenges for the application of these approaches. Our aim is
to instigate the study of new questions about animal sociality using the new
toolbox of multilayer network analysis.Comment: Thoroughly revised; title changed slightl
Petrology and Geochronology of Metamorphic Zircon
Zircon is unusually well suited for investigating metamorphic processes because it is readily analyzed for UâPb ages, it harbors diverse mineral inclusions, and its chemistry can be linked to metamorphic parageneses and PâT paths. Metamorphic zircon chemistry and ages are relevant only at the subâgrain micron scale, and consequently many analytical methods, such as depth profiling, have been developed to exploit such spatially resolute inforÂmation. Here we review how metamorphic zircon grows, and how its chemistry and inclusion assemblages may be used to link the age of a zircon domain to its metamorphic PâT condition. Domainâspecific ages and inclusion assemblages from ultrahighâpressure (UHP) zircons constrain rates of subduction and exhumation. Textures and chemistry of zircon and garnet from highâ and ultrahigh temperature (UHT) rocks reveal petrogenetic implications of deep crustal heating, melting, and melt crystallization. Trace elements, inclusion assemblages, and oxygen isotopes in zircon show that dehydration reactions may catalyze zircon growth during subduction. Future research should include identifying natural systems that constrain diffusion rates, determining crystalâchemical controls on trace element uptake in zircon and garnet for understanding how rare earth budgets and patterns change during metamorphism, and identifying underlying principles that govern the dissolution and reprecipitation of zircon during metamorphism
Professional decision-making in medicine: Development of a new measure and preliminary evidence of validity
INTRODUCTION: This study developed a new Professional Decision-Making in Medicine Measure that assesses the use of effective decision-making strategies: seek help, manage emotions, recognize consequences and rules, and test assumptions and motives. The aim was to develop a content valid measure and obtain initial evidence for construct validity so that the measure could be used in future research or educational assessment.
METHODS: Clinical scenario-based items were developed based on a review of the literature and interviews with physicians. For each item, respondents are tasked with selecting two responses (out of six plausible options) that they would choose in that situation. Three of the six options reflect a decision-making strategy; these responses are scored as correct. Data were collected from a sample of 318 fourth-year medical students in the United States. They completed a 16-item version of the measure (Form A) and measures of social desirability, moral disengagement, and professionalism attitudes. Professionalism ratings from clerkships were also obtained. A sub-group (n = 63) completed a second 16-item measure (Form B) to pilot test the instrument, as two test forms are useful for pre-posttest designs.
RESULTS: Scores on the new measure indicated that, on average, participants answered 75% of items correctly. Evidence for construct validity included the lack of correlation between scores on the measure and socially desirable responding, negative correlation with moral disengagement, and modest to low correlations with professionalism attitudes. A positive correlation was observed with a clerkship rating focused on professionalism in peer interactions.
CONCLUSIONS: These findings demonstrate modest proficiency in the use of decision-making strategies among fourth-year medical students. Additional research using the Professional Decision-Making Measure should explore scores among physicians in various career stages, and the causes and correlates of scores. Educators could utilize the measure to assess courses that teach decision-making strategies
Broad Sterile Neutrinos & the Reactor/Gallium Tension
Significant evidence exists for the apparent disappearance of electron-type
neutrinos in radioactive source experiments. Yet, interpreted within the
standard `3+1 sterile neutrino scenario', precision short-baseline measurements
of electron antineutrinos from nuclear reactors strongly disagree with these
results. Recently, it has been demonstrated that allowing for a finite
wavepacket size for the reactor neutrinos can ameliorate such a tension,
however the smallness of the required wavepackets is a subject of intense
debate. In this work, we demonstrate that a `broad' sterile neutrino may relax
this tension in much the same way. Such a phenomenological possibility can
arise in plausible hidden sector scenarios, such as a clockwork-style sector,
for which we provide a concrete microscopic model
Regular Language Distance and Entropy
This paper addresses the problem of determining the distance between two regular languages. It will show how to expand Jaccard distance, which works on finite sets, to potentially-infinite regular languages.
The entropy of a regular language plays a large role in the extension. Much of the paper is spent investigating the entropy of a regular language. This includes addressing issues that have required previous authors to rely on the upper limit of Shannon\u27s traditional formulation of channel capacity, because its limit does not always exist. The paper also includes proposing a new limit based formulation for the entropy of a regular language and proves that formulation to both exist and be equivalent to Shannon\u27s original formulation (when it exists). Additionally, the proposed formulation is shown to equal an analogous but formally quite different notion of topological entropy from Symbolic Dynamics -- consequently also showing Shannon\u27s original formulation to be
equivalent to topological entropy.
Surprisingly, the natural Jaccard-like entropy distance is trivial in most cases. Instead, the entropy sum distance metric is suggested, and shown to be granular in certain situations
Xeroderma Pigmentosum Group C Deficiency Alters Cigarette Smoke DNA Damage Cell Fate and Accelerates Emphysema Development
Cigarette smoke (CS) exposure is a major risk factor for the development of emphysema, a common disease characterized by loss of cells comprising the lung parenchyma. The mechanisms of cell injury leading to emphysema are not completely understood but are thought to involve persistent cytotoxic or mutagenic DNA damage induced by CS. Using complementary cell culture and mouse models of CS exposure, we investigated the role of the DNA repair protein, xeroderma pigmentosum group C (XPC), on CS-induced DNA damage repair and emphysema. Expression of XPC was decreased in mouse lungs after chronic CS exposure and XPC knockdown in cultured human lung epithelial cells decreased their survival after CS exposure due to activation of the intrinsic apoptosis pathway. Similarly, cell autophagy and apoptosis were increased in XPC-deficient mouse lungs and were further increased by CS exposure. XPC deficiency was associated with structural and functional changes characteristic of emphysema, which were worsened by age, similar to levels observed with chronic CS exposure. Taken together, these findings suggest that repair of DNA damage by XPC plays an important and previously unrecognized role in the maintenance of alveolar structures. These findings support that loss of XPC, possibly due to chronic CS exposure, promotes emphysema development and further supports a link between DNA damage, impaired DNA repair, and development of emphysema
Postmenopausal Women With Greater Paracardial Fat Have More Coronary Artery Calcification Than Premenopausal Women: The Study of Women's Health Across the Nation (SWAN) Cardiovascular Fat Ancillary Study.
BackgroundVolumes of paracardial adipose tissue (PAT) and epicardial adipose tissue (EAT) are greater after menopause. Interestingly, PAT but not EAT is associated with estradiol decline, suggesting a potential role of menopause in PAT accumulation. We assessed whether volumes of heart fat depot (EAT and PAT) were associated with coronary artery calcification (CAC) in women at midlife and whether these associations were modified by menopausal status and estradiol levels.Methods and resultsEAT and PAT volumes and CAC were measured using electron beam computed tomography scans. CAC was evaluated as (1) the presence of CAC (CAC Agatston score â„10) and (2) the extent of any CAC (log CAC Agatston score >0). The study included 478 women aged 50.9 years (58% pre- or early perimenopausal, 10% late perimenopausal, and 32% postmenopausal). EAT was significantly associated with CAC measures, and these associations were not modified by menopausal status or estradiol. In contrast, associations between PAT and CAC measures were modified by menopausal status (interaction-Pâ€0.01). Independent of study covariates including other adiposity measures, each 1-SD unit increase in log PAT was associated with 102% higher risk of CAC presence (P=0.04) and an 80% increase in CAC extent (P=0.008) in postmenopausal women compared with pre- or early perimenopausal women. Additional adjustment for estradiol and hormone therapy attenuated these differences. Moreover, the association between PAT and CAC extent was stronger in women with lower estradiol levels (interaction P=0.004).ConclusionsThe findings suggest that PAT is a potential menopause-specific coronary artery disease risk marker, supporting the need to monitor and target this fat depot for intervention in women at midlife
The contribution of halo white dwarf binaries to the laser interferometer space antenna signal
Galactic double white dwarfs were postulated as a source of confusion limited noise for the Laser Interferometer Space Antenna (LISA), the future space-based gravitational wave observatory. Until very recently, the Galactic population consisted of a relatively well-studied disk population, a somewhat studied smaller bulge population and a mostly unknown, but potentially large halo population. It has been argued that the halo population may produce a signal that is much stronger (factor of ĂąËÂŒ5 in spectral amplitude) than the disk population. However, this surprising result was not based on an actual calculation of a halo white dwarf population, but was derived on (1) the assumption that one can extrapolate the halo population properties from those of the disk population and (2) the postulated (unrealistically) high number of white dwarfs in the halo. We perform the first calculation of a halo white dwarf population using population synthesis models. Our comparison with the signal arising from double white dwarfs in the Galactic disk+bulge clearly shows that it is impossible for the double white dwarf halo signal to exceed that of the rest of the Galaxy. Using microlensing results to give an upper limit on the content of white dwarfs in the halo (ĂąËÂŒ30% baryonic mass in white dwarfs), our predicted halo signal is a factor of 10 lower than the disk+bulge signal. Even in the implausible case, where all of the baryonic halo mass is found in white dwarfs, the halo signal does not become comparable to that of the disk+bulge, and thus would still have a negligible effect on the detection of other LISA sources. Ă© 2009. The American Astronomical Society. All rights reserved
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