4,380 research outputs found
Slow and fast components in the X-ray light curves of Gamma-Ray Bursts
Gamma-ray burst light curves show quite different patterns: from very simple
to extremely complex. We present a temporal and spectral study of the light
curves in three energy bands (2-5, 5-10, 10-26 keV) of ten GRBs detected by the
Wide Field Cameras on board BeppoSAX. For some events the time profiles are
characterized by peaks superposed on a slowly evolving pedestal, which in some
cases becomes less apparent at higher energies. We describe this behaviour with
the presence of two components (slow and fast) having different variability
time scales. We modelled the time evolution of slow components by means of an
analytical function able to describe asymmetric rising and decaying profiles.
The residual light curves, after the subtraction of the slow components,
generally show structures more similar to the original curves in the highest
energy band. Spectral study of these two components was performed evaluating
their hardness ratios, used also to derive photon indices. Slow components are
found generally softer than the fast ones suggesting that their origin is
likely different. Being typical photon indices lower than those of the
afterglows there is no evidence that the emission processes are similar.
Another interesting possibility is that slow components can be related to the
presence of a hot photosphere having a thermal spectrum with kT around a few
keV superposed to a rapid variable non-thermal emission of the fast component.Comment: 16 pages, 20 figures (18 color, 2 B&W), accepted for publication in
Astronomy and Astrophysic
Medico-legal and criminological suicide diagnosis on historical cases: testing a new methodology
This work proposes a new combination of criteria for the suicide diagnosis applied to these three famous historical cases: Judas Iscariot, Antony and Cleopatra, Vincent Van Gogh. The specific criteria (suicide statistics and dynamics, correlation of types of injury and how they were produced, evidence gathered during official inspections in loco, and previous psychiatric disorders in the victim) have been applied to famous historical cases from different socio-cultural contexts and epochs in order to tackle the issue of suicide without prejudice. The results confirm the essential role of systematic analysis of all elements from an equivocal death crime scene investigation to be able to distinguish suicide from homicide or natural and accidental death. The scores obtained in each three examined case emphasize the relevance of every single criterion of the methodology for different scenarios
Functional biases in GRB's spectral parameter correlations
Gamma Ray Bursts (GRBs) show evidence of different spectral shapes, light
curves, duration, host galaxies and they explode within a wide redshift range.
However, the most of them seems to follow very tight correlations among some
observed quantities relating to their energetic. If true, these correlations
have significant implications on burst physics, giving constraints on
theoretical models. Moreover, several suggestions have been made to use these
correlations in order to calibrate GRBs as standard candles and to constrain
the cosmological parameters. We investigate the cosmological relation between
low energy index in GRBs prompt spectra and the redshift . We
present a statistical analysis of the relation between the total isotropic
energy and the peak energy (also known as Amati relation) in
GRBs spectra searching for possible functional biases. Possible implications on
the vs relation of the vs correlation are
evaluated. We used MonteCarlo simulations and the boostrap method to evaluate
how large are the effects of functional biases on the vs . We
show that high values of the linear correlation coefficent, up to about 0.8, in
the vs relation are obtained for random generated samples of
GRBs, confirming the relevance of functional biases. Astrophysical consequences
from vs relation are then to be revised after a more accurate
and possibly bias free analysis.Comment: 6 pages, 6 figures, conference poster session: "070228: The Next
Decade of Gamma-Ray Burst Afterglows", Amsterdam, March 2007, MNRAS submitte
Constitutional Limitations on State-Imposed Continuing Competency Requirements for Licensed Professionals
The role of attitude, control and intention to explain fruit and vegetable intake among racial/ethnic minority women with low socioeconomic status
OBJECTIVE: Fruit and Vegetable (FV) intake-a modi able risk factor for chronic diseases-is lower among racial/ethnic minorities and low Socio- Economic Status (SES) groups when compared to other populations. The Theory of Planned Behavior (TPB) is one theoretical model studied to explain and in uence individual health behaviors, including FV intake, in middle class populations, but not exclusively in diverse, low SES groups. This cross-sectional study evaluated the utility of select TPB variables to explain intention to consume and intake of FV in this population.
DESIGN: Demographics, BMI, select TPB variables, and FV intake were measured via survey. Bivariate analyses were conducted to explore relationships between variables. Hierarchical regression analyses were used to t two models: one to explain intention and one to explain behavior with regard to FV vegetable intake.
RESULTS: Participants (n=114) age 25-69 years and were mostly African American/Black and Hispanic (21.9% and 73%, respectively). The TPB variable perceived behavioral control was the only signi cant predictor of intention to consume FV (OR=2.55, 95% CI OR: 1.23, 5.27), and with BMI, FV intake (R2=0.08; F [2,130] =5.72, p=0.0042).
CONCLUSION: Perceived behavioral control and BMI are the most signi cant predictors of FV intake but explain only 8% of the variability in intake in our cohort. Our results support prior research which suggests an attenuation of the intention-behavior relationship by SES, and may question the utility of the TPB as it is currently operationalized as a foundational model for future health behavior change research and programs in low SES racial/ethnic minorities
Pilot and feasibility test of an implementation intention intervention to improve fruit and vegetable intake among women with low socioeconomic status
Fruit and vegetable intake (FVI), a modifiable risk factor for chronic diseases, is lower in low socioeconomic status (SES) populations. Implementation intentions (a specific type of planning that extends the Theory of Planned Behavior) has been studied to improve FVI, but not exclusively with low SES groups. Using mixed methods, we evaluated the feasibility, acceptability, and preliminary efficacy of an implementation intention intervention (versus a general plan) to increase FVI in women with low SES. For the pilot randomized controlled trial, demographics, body mass index, attitude, perceived behavioral control, goal intention strength, and FVI were measured at baseline and FVI again 1-month following the intervention. Feasibility data were collected for recruitment, randomization, retention, and assessment procedures and compared to predetermined targets. Semi-structured interview data was analyzed for emergent themes regarding acceptability of the trial. Preliminary efficacy of the intervention to improve FVI was analyzed descriptively. Feasibility targets were met for randomization (100% vs. ≥80% target), retention (93.5% vs. ≥70% target) and the assessment metrics missing data points (2% vs. ≤10% target) and days from intervention to follow up (mean=69.2, sd=42.6 vs.days). Targets for recruitment were not met with the exception of participants giving informed consent (100% vs. ≥70% target). Participants described the intervention as enjoyable and reported behavioral constructs outside of those measured as important to improve FVI. Limited efficacy analysis suggested that both groups increased their FVI (experimental: +0.17 servings per day, 95% CI: -0.85, 1.20; control: +0.50 servings per day, 95% CI: -0.56, 1.58). Further research which examines interventions based upon behavior change models to improve dietary health behaviors in marginalized groups is needed
The CLT Panels in Structural Restoration: Characteristics and Technical Regulations
Wood can represent a valid and important alternative to the most commonly
used structural materials for the restoration of masonry buildings, with a view to efficient, effective and "conscious" renovation. Today, the modern technologies allows to overcome the structural limits of solid wood due to its own anisotropy. The use of composite wood elements makes possible to obtain excellent mechanical performances that consent to evaluate aspects such as the use of low environmental impact retrofit strategies. The aim of this work is the analysis of mechanical parameters related to CLT (cross laminated timber) panels in order to determine their possible use in the structural restoration of masonry buildings. The CLT panels consist of solid wood planks superimposed so that each layer has the fibres rotated ninety degrees with respect to the adjacent layer. The layers (always in odd number and at least three) can be connected by discrete joints, pins and nails, or glued together. This onfiguration enables to product large structural elements with considerable thickness. Two different experimental test campaigns were carried out on samples of panels with three and five glued layers. The purpose of experimentation activities was to evaluate the bending deformation of the wooden elements and shear strength of the bonding sections. All the tests were processed according to the provisions contained in the UNI standards. The test results were then compared with different theoretical calculation models to determine the one that best represents the tested material. The tests outcomes have shown that some characteristics of the material, such as the remarkable ductility, open different scenarios of use for the CLT panels in the field of structural restoration of masonry buildings
Applied linguistics as a manifestation of exo-, meso- and endo-symbiosis
An assumption is made that applied linguistics may be viewed as an outcome of an interplay of a dichotomy of endogenous and exogenous symbionts, mediated by important mesogenous symbionts acting jointly within the domain of language and communication. All of them form a system of bifurcations which may generally be called ‘a flow tool-language design’ or The Bifurcational Model of Symbiosis (BiMoS). In this model, bifurcations form a ‘grammar of bifurcations’ whose power is symbiotic in the overall functioning of language. Furthermore, the occurrence of the above mentioned types of symbionts on the language side allows for a division of ‘linguolabourese’ (or the whole ‘life of language’ as opposed to ‘instrumentolabourese’, or the whole ‘life of tools’) into three more or less distinct and interconnected areas of symbiosis: the exogenous area, the mesogenous area, and the endogenous area, respectively. The afore mentioned areas further justify a division of linguistics into three respective types: exogenous (exo-) linguistics, mesogenous (meso-) linguistics, and endogenous (endo-) linguistics. Their subdomains of interest vary but are highly interconnected, blended and synergistic. Applied linguistics is viewed here as belonging predominantly to (or taking theoretical and practical interest in) the mesogenous and endogenous areas of linguolabourese, though it is strongly supported by the underlying exogenous area.An assumption is made that applied linguistics may be viewed as an outcome of an interplay of a dichotomy of endogenous and exogenous symbionts, mediated by important mesogenous symbionts acting jointly within the domain of language and communication. All of them form a system of bifurcations which may generally be called ‘a flow tool-language design’ or The Bifurcational Model of Symbiosis (BiMoS). In this model, bifurcations form a ‘grammar of bifurcations’ whose power is symbiotic in the overall functioning of language. Furthermore, the occurrence of the above mentioned types of symbionts on the language side allows for a division of ‘linguolabourese’ (or the whole ‘life of language’ as opposed to ‘instrumentolabourese’, or the whole ‘life of tools’) into three more or less distinct and interconnected areas of symbiosis: the exogenous area, the mesogenous area, and the endogenous area, respectively. The afore mentioned areas further justify a division of linguistics into three respective types: exogenous (exo-) linguistics, mesogenous (meso-) linguistics, and endogenous (endo-) linguistics. Their subdomains of interest vary but are highly interconnected, blended and synergistic. Applied linguistics is viewed here as belonging predominantly to (or taking theoretical and practical interest in) the mesogenous and endogenous areas of linguolabourese, though it is strongly supported by the underlying exogenous area
Relationships Between Black-Legged Kittiwake Nest-Site Characteristics and Susceptibility to Predation by Large Gulls
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