11,390 research outputs found
An invitation to grieve: reconsidering critical incident responses by support teams in the school setting
This paper proposes that consideration could be given to an invitational intervention rather than an expectational intervention when support personnel respond to a critical incident in schools. Intuitively many practitioners know that it is necessary for guidance/counselling personnel to intervene in schools in and following times of trauma. Most educational authorities in Australia have mandated the formulation of a critical incident intervention plan. This paper defines the term critical incident and then outlines current intervention processes, discussing the efficacy of debriefing interventions. Recent literature suggests that even though it is accepted that a planned intervention is necessary, there is scant evidence as to the effectiveness of debriefing interventions in stemming later symptoms of post traumatic stress disorder. The authors of this paper advocate for an expressive therapy intervention that is invitational rather than expectational, arguing that not all people respond to trauma in the same way and to expect that they will need to recall and retell what has happened is most likely a dangerous assumption. A model of invitation using Howard Gardner’s (1983) multiple intelligences is proposed so that students are invited to grieve and understand emotionally what is happening to them following a critical incident
Natural entropy fluctuations discriminate similar looking electric signals emitted from systems of different dynamics
Complexity measures are introduced, that quantify the change of the natural
entropy fluctuations at different length scales in time-series emitted from
systems operating far from equilibrium. They identify impending sudden cardiac
death (SD) by analyzing fifteen minutes electrocardiograms, and comparing to
those of truly healthy humans (H). These measures seem to be complementary to
the ones suggested recently [Phys. Rev. E {\bf 70}, 011106 (2004)] and
altogether enable the classification of individuals into three categories: H,
heart disease patients and SD. All the SD individuals, who exhibit critical
dynamics, result in a common behavior.Comment: Published in Physical Review
Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy
The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference
Partiality, revisited: the partiality monad as a quotient inductive-inductive type
Capretta's delay monad can be used to model partial computations, but it has the "wrong" notion of built-in equality, strong bisimilarity. An alternative is to quotient the delay monad by the "right" notion of equality, weak bisimilarity. However, recent work by Chapman et al. suggests that it is impossible to define a monad structure on the resulting construction in common forms of type theory without assuming (instances of) the axiom of countable choice. Using an idea from homotopy type theory - a higher inductive-inductive type - we construct a partiality monad without relying on countable choice. We prove that, in the presence of countable choice, our partiality monad is equivalent to the delay monad quotiented by weak bisimilarity. Furthermore we outline several applications
First XMM-Newton Observations of the Globular Cluster M22
We have examined preliminary data of the globular cluster, M22, from the EPIC
MOS detectors on board XMM-Newton. We have detected 27 X-ray sources within the
centre of the field of view, 24 of which are new detections. Three sources were
found within the core of the cluster. From spectral analysis of the X-ray
sources, it is possible that the object at the centre of the core is a
quiescent X-ray transient and those lying further out are maybe cataclysmic
variables.Comment: 6 pages, 3 figures, accepted to be published in Astronomy and
Astrophysic
Instability of the symmetric Couette-flow in a granular gas: hydrodynamic field profiles and transport
We investigate the inelastic hard disk gas sheared by two parallel bumpy
walls (Couette-flow). In our molecular dynamic simulations we found a
sensitivity to the asymmetries of the initial condition of the particle places
and velocities and an asymmetric stationary state, where the deviation from
(anti)symmetric hydrodynamic fields is stronger as the normal restitution
coefficient decreases. For the better understanding of this sensitivity we
carried out a linear stability analysis of the former kinetic theoretical
solution [Jenkins and Richman: J. Fluid. Mech. {\bf 171} (1986)] and found it
to be unstable. The effect of this asymmetry on the self-diffusion coefficient
is also discussed.Comment: 9 pages RevTeX, 14 postscript figures, sent to Phys. Rev.
An XMM-Newton observation of the globular cluster Omega Centauri
We report on a deep XMM-Newton EPIC observation of the globular cluster Omega
Cen performed on August 13th, 2001. We have detected 11 and 27 faint X-ray
sources in the core and half mass radii, searching down to a luminosity of 1.3
x 10^{31} erg s^{-1} in the 0.5-5 keV range. Most sources have bolometric X-ray
luminosities between ~ 10^{31}-10^{32} erg s^{-1}. We present the color-color
and hardness-intensity diagrams of the source sample, as well as high-quality
EPIC spectra of the brightest objects of the field; including the two candidate
Cataclysmic Variables (CVs) in the core and the quiescent neutron star low-mass
X-ray binary candidate. The spectra of the latter objects fully support their
previous classification. We show that the bulk of sources are hard and
spectrally similar to CVs. The lack of soft faint sources might be related to
the absence of millisecond pulsars in the cluster. The XMM-Newton observations
reveal the presence of an excess of sources well outside the core of the
cluster where several RS CVn binaries have already been found. We have also
analyzed a publicly available Chandra ACIS-I observation performed on January
24-25th, 2000, to improve the XMM-Newton source positions and to search for
source intensity variations between the two data sets. 63 XMM-Newton sources
have a Chandra counterpart, and 15 sources within the half-mass radius have
shown time variability. Overall, the general properties of the faint X-ray
sources in Omega Cen suggest that they are predominantly CVs and active
binaries (RS CVn or BY Dra).Comment: 21 pages, 2 color figures, 8 B&W figures. Accepted for publication in
Astronomy and Astrophysic
Semileptonic B decays to excited charmed mesons
Exclusive semileptonic B decays into excited charmed mesons are investigated
at order in the heavy quark effective theory. Differential
decay rates for each helicity state of the four lightest excited mesons
(, , , and ) are examined. At zero recoil,
corrections to the matrix elements of the weak currents can
be written in terms of the leading Isgur-Wise functions for the corresponding
transition and meson mass splittings. A model independent prediction is found
for the slope parameter of the decay rate into helicity zero at zero
recoil. The differential decay rates are predicted, including
corrections with some model dependence away from zero
recoil and including order corrections. Ratios of various exclusive
branching ratios are computed. Matrix elements of the weak currents between
mesons and other excited charmed mesons are discussed at zero recoil to order
. These amplitudes vanish at leading order, and can be
written at order in terms of local matrix elements.
Applications to decay sum rules and factorization are presented.Comment: 39 pages revtex including 10 figures, uses epsf. Substantial
improvements throughout the pape
XMM-Newton X-ray and optical observations of the globular clusters M 55 and NGC 3201
We have observed two low concentration Galactic globular clusters with the
X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction
of M 55 and 62 in the field of view of NGC 3201. Using the statistical Log
N-Log S relationship of extragalactic sources derived from XMM-Newton Lockman
Hole observations, to estimate the background source population, we estimate
that very few of the sources (1.5+/-1.0) in the field of view of M 55 actually
belong to the cluster. These sources are located in the centre of the cluster
as we expect if the cluster has undergone mass segregation. NGC 3201 has
approximately 15 related sources, which are centrally located but are not
constrained to lie within the half mass radius. The sources belonging to this
cluster can lie up to 5 core radii from the centre of the cluster which could
imply that this cluster has been perturbed. Using X-ray (and optical, in the
case of M 55) colours, spectral and timing analysis (where possible) and
comparing these observations to previous X-ray observations, we find evidence
for sources in each cluster that could be cataclysmic variables, active
binaries, millisecond pulsars and possible evidence for a quiescent low mass
X-ray binary with a neutron star primary, even though we do not expect any such
objects in either of the clusters, due to their low central concentrations. The
majority of the other sources are background sources, such as AGN.Comment: 12 pages, 7 figures, accepted to be published in A&
Heavy- to light-meson transition form factors
Semileptonic heavy -> heavy and heavy -> light meson transitions are studied
as a phenomenological application of a heavy-quark limit of Dyson-Schwinger
equations. Employing two parameters: E, the difference between the mass of the
heavy meson and the effective-mass of the heavy quark; and Lambda, the width of
the heavy-meson Bethe-Salpeter amplitude, we calculate f_+(t) for all decays on
their entire kinematically accessible t-domain. Our study favours f_B in the
range 0.135-0.17 GeV and with E=0.44 GeV and 1/Lambda = 0.14 fm we obtain
f_+^{B pi}(0) = 0.46. As a result of neglecting 1/m_c-corrections, we estimate
that our calculated values of \rho^2 = 0.87 and f_+^{DK}(0)=0.62 are too low by
approximately 15%. However, the bulk of these corrections should cancel in our
calculated values of Br(D -> \pi l nu)/Br(D -> K l nu)=0.13 and f_+^{D
pi}(0)/f_+^{DK}(0) = 1.16.Comment: 26 pages, 3 figures, REVTE
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