657 research outputs found
Validation of the English language version of the Violent Ideations Scale
This study used a within-participant design to evaluate the concurrent validity and test–retest reliability of the Violent Ideations Scale in a general population, English-speaking opportunistic sample. Data from 116 adult participants (M age = 33.7, SD = 11.9, male = 30 [25.9%]) were used to compare scores on the Violent Ideations Scale and Aggression Questionnaire and responses to the Schedule of Imagined Violence. A subgroup of 27 participants (M age = 37.2, SD = 13.6, male = 8 [29.6%]) completed the Violent Ideations Scale on a second occasion, 2 weeks later. The Violent Ideations Scale was found to correlate significantly with the Aggression Questionnaire subscale and total scores, with the strongest correlations being with physical aggression and total scores. Participants were more likely to be categorized as having experienced a violent ideation based on responses to the Violent Ideation Scale, compared with the Schedule of Imagined Violence, most likely due to the Schedule of Imagined Violence underestimating the prevalence of violent ideation. A significant, strong correlation was found between total Violent Ideations Scale scores at Time 1 and Time 2. Overall, the Violent Ideations Scale was found to have concurrent validity when compared with the Aggression Questionnaire and good test–retest reliability, suggesting that it would be suitable for use with a nonclinical, English-speaking sampl
Counselling in primary care : a systematic review of the evidence
Primary objective: To undertake a systematic review which aimed to locate, appraise and synthesise evidence to obtain a reliable overview of the clinical effectiveness, cost-effectiveness and user perspectives regarding counselling in primary care.
Main results: Evidence from 26 studies was presented as a narrative synthesis and demonstrated that counselling is effective in the short term, is as effective as CBT with typical heterogeneous primary care populations and more effective than routine primary care for the treatment of non-specific generic psychological problems, anxiety and depression. Counselling may reduce levels of referrals to psychiatric services, but does not appear to reduce medication, the number of GP consultations or overall
costs. Patients are highly satisfied with the counselling they have received in primary care and prefer counselling to medication for depression.
Conclusions and implications for future research: This review demonstrates the value of counselling as a valid
choice for primary care patients and as a broadly effective therapeutic intervention for a wide range of generic psychological conditions presenting in the primary care setting. More rigorous clinical and cost-effectiveness trials are needed together with surveys of more typical users of primary care services
Bifurcating spatial patterns arising from travelling waves in a tissue interaction model
We analyse a tissue interaction model recently proposed to account for pattern formation in the morphogenesis of skin organ primordia. We show that the model can exhibit travelling wave solutions which leave in their wake a spatially nonuniform, steady state solution
Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating
Traditionally stellar radiation has been the only heat source considered
capable of determining global climate on long timescales. Here we show that
terrestrial exoplanets orbiting low-mass stars may be tidally heated at high
enough levels to induce a runaway greenhouse for a long enough duration for all
the hydrogen to escape. Without hydrogen, the planet no longer has water and
cannot support life. We call these planets "Tidal Venuses," and the phenomenon
a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases
tidal heating. Hence, some planets may form with large eccentricity, with its
accompanying large tidal heating, and lose their water, but eventually settle
into nearly circular orbits (i.e. with negligible tidal heating) in the
habitable zone (HZ). However, these planets are not habitable as past tidal
heating desiccated them, and hence should not be ranked highly for detailed
follow-up observations aimed at detecting biosignatures. Planets orbiting stars
with masses <0.3 solar masses may be in danger of desiccation via tidal
heating. We apply these concepts to Gl 667C c, a ~4.5 Earth-mass planet
orbiting a 0.3 solar mass star at 0.12 AU. We find that it probably did not
lose its water via tidal heating as orbital stability is unlikely for the high
eccentricities required for the tidal greenhouse. As the inner edge of the HZ
is defined by the onset of a runaway or moist greenhouse powered by radiation,
our results represent a fundamental revision to the HZ for non-circular orbits.
In the appendices we review a) the moist and runaway greenhouses, b) hydrogen
escape, c) stellar mass-radius and mass-luminosity relations, d) terrestrial
planet mass-radius relations, and e) linear tidal theories. [abridged]Comment: 59 pages, 11 figures, accepted to Astrobiology. New version includes
an appendix on the water loss timescal
Generalized empty-interval method applied to a class of one-dimensional stochastic models
In this work we study, on a finite and periodic lattice, a class of
one-dimensional (bimolecular and single-species) reaction-diffusion models
which cannot be mapped onto free-fermion models.
We extend the conventional empty-interval method, also called
{\it interparticle distribution function} (IPDF) method, by introducing a
string function, which is simply related to relevant physical quantities.
As an illustration, we specifically consider a model which cannot be solved
directly by the conventional IPDF method and which can be viewed as a
generalization of the {\it voter} model and/or as an {\it epidemic} model. We
also consider the {\it reversible} diffusion-coagulation model with input of
particles and determine other reaction-diffusion models which can be mapped
onto the latter via suitable {\it similarity transformations}.
Finally we study the problem of the propagation of a wave-front from an
inhomogeneous initial configuration and note that the mean-field scenario
predicted by Fisher's equation is not valid for the one-dimensional
(microscopic) models under consideration.Comment: 19 pages, no figure. To appear in Physical Review E (November 2001
Semi-automatic enrichment of crowdsourced synonymy networks: the WISIGOTH system applied to Wiktionary
International audienceSemantic lexical resources are a mainstay of various Natural Language Processing applications. However, comprehensive and reliable resources are rare and not often freely available. Handcrafted resources are too costly for being a general solution while automatically-built resources need to be validated by experts or at least thoroughly evaluated. We propose in this paper a picture of the current situation with regard to lexical resources, their building and their evaluation. We give an in-depth description of Wiktionary, a freely available and collaboratively built multilingual dictionary. Wiktionary is presented here as a promising raw resource for NLP. We propose a semi-automatic approach based on random walks for enriching Wiktionary synonymy network that uses both endogenous and exogenous data. We take advantage of the wiki infrastructure to propose a validation "by crowds". Finally, we present an implementation called WISIGOTH, which supports our approach
Search for composite and exotic fermions at LEP 2
A search for unstable heavy fermions with the DELPHI detector at LEP is
reported. Sequential and non-canonical leptons, as well as excited leptons and
quarks, are considered. The data analysed correspond to an integrated
luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV
and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172
GeV and 161 GeV. The search for pair-produced new leptons establishes 95%
confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2,
depending on the channel. The search for singly produced excited leptons and
quarks establishes upper limits on the ratio of the coupling of the excited
fermio
Search for charginos in e+e- interactions at sqrt(s) = 189 GeV
An update of the searches for charginos and gravitinos is presented, based on
a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector
in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was
found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a
centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by
combining the chargino searches with neutralino searches at the Z resonance
implies a limit on the mass of the lightest neutralino which, for a heavy
sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure
Magnetized Kelvin-Helmholtz instability in the presence of a radiation field
The purpose of this study is to analyze the dynamical role of a radiation
field on the growth rate of the unstable Kelvin - Helmholtz (KH) perturbations.
As a first step toward this purpose, the analyze is done in a general way,
irrespective of applying the model to a specific astronomical system. The
transition zone between the two layers of the fluid is ignored. Then, we
perform a linear analysis and by imposing suitable boundary conditions and
considering a radiation field, we obtain appropriate dispersion relation.
Unstable modes are studied by solving the dispersion equation numerically, and
then growth rates of them are obtained. By analyzing our dispersion relation,
we show that for a wide range of the input parameters, the radiation field has
a destabilizing effect on KH instability. In eruptions of the galaxies or
supermassive stars, the radiation field is dynamically important and because of
the enhanced KH growth rates in the presence of the radiation; these eruptions
can inject more momentum and energy into their environment and excite more
turbulent motions.Comment: Accepted for publication in Astrophysics and Space Scienc
Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP
Promptly decaying lightest neutralinos and long-lived staus are searched for
in the context of light gravitino scenarios. It is assumed that the stau is the
next to lightest supersymmetric particle (NLSP) and that the lightest
neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector
at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of
the production of these particles is found. Hence, lower mass limits for both
kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is
found to be greater than 71.5 GeV/c^2. In the search for long-lived stau,
masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10
to 150 \eVcc . Combining this search with the searches for stable heavy leptons
and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc
may be set for the stau mas
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