384 research outputs found
A randomised open-label study of tiagabine given two or three times daily in refractory epilepsy
SummaryEfficacy and tolerability of tiagabine was evaluated in patients with non-controlled partial seizures in a multicentre, open-label, parallel group study. Tiagabine was administered either two (b.i.d.) or three times daily (t.i.d.) as adjunctive therapy and titrated stepwise to a target of 40mg/day during a 12-week, fixed-schedule titration period; this was followed by a 12-week flexible continuation period. The primary efficacy endpoint was the proportion of patients completing the fixed-schedule titration period. A total of 243 patients were randomised and received treatment, 123 to b.i.d. and 120 to t.i.d. dosing. Fewer patients in the b.i.d. (76 and 62%) than in the t.i.d. (87 and 72%) group completed the fixed-schedule titration period (OR: 0.562; 95% CI: 0.309â1.008; P=0.0532). The median percentage decrease in all types of seizure (excluding status epilepticus) during the fixed schedule titration period was 33.4% for the b.i.d. and 23.8% for the t.i.d. groups (P=0.9634; Van Elteren's test). The proportion of responders was similar for the b.i.d. and t.i.d. groups. There were no significant differences between dosage regimens in the change in median seizure rates from baseline. Adverse events were more frequent during the titration than the continuation period. Most events were mild and related to the central nervous system. Although their incidence was similar between treatment groups, severity was more frequent in the b.i.d. group. Our results suggest that during titration tiagabine is better tolerated with t.i.d. dosing, but during long-term maintenance, a t.i.d. schedule is as effective and well tolerated as b.i.d
School-based targeted prevention compared to specialist mental health treatment for youth anxiety
Background
The âFRIENDS for lifeâ program (FRIENDS) is a 10-session cognitive behavioral therapy (CBT) program used for prevention and treatment of youth anxiety. There is discussion about whether FRIENDS is best applied as prevention or as treatment.
Methods
We compared FRIENDS delivered in schools as targeted prevention to a previous specialist mental health clinic trial. The targeted prevention sample (N = 82; Mage = 11.6 years, SD = 2.1; 75.0% girls) was identified and recruited by school nurses in collaboration with a community psychologist. The clinical sample (N = 88, Mage = 11.7 years, SD = 2.1; 54.5% girls) was recruited for a randomized controlled trial from community child- and adolescent psychiatric outpatient clinics and was diagnosed with anxiety disorders.
Results
Both samples showed significantly reduced anxiety symptoms from baseline to postintervention, with medium mean effect sizes across raters (youths and parents) and timepoints (post; 12-months follow-up). Baseline youth-reported anxiety symptom levels were similar between the samples, whereas parent-reported youth anxiety was higher in the clinical sample.
Conclusions
The study suggests that self-reported anxiety levels may not differ between youth recruited in schools and in clinic settings. The results indicate promising results of the FRIENDS program when delivered in schools by less specialized health personnel from the school health services, as well as when delivered in clinics by trained mental health professionals.publishedVersio
Dimeric FcÎłR ectodomains detect pathogenic anti-platelet factor 4-heparin antibodies in heparin-induced thromobocytopenia
Background
Heparinâinduced thrombocytopenia (HIT) is a major and potentially fatal consequence of antibodies produced against platelet factor 4 (PF4)âheparin complexes following heparin exposure. Not all antiâPF4âheparin antibodies are pathogenic, so overdiagnosis can occur, with resulting inappropriate use of alternative anticoagulation therapies that have associated risks of bleeding. However, definitive platelet functional assays are not widely available for routine analysis.
Objectives
To assess the utility of dimeric recombinant soluble FcÎłRIIa (rsFcÎłRIIa) ectodomains for detecting HIT antibodies.
Patients/Methods
Plasma from 27 suspected HIT patients were tested for pathogenic antiâPF4âheparin antibodies by binding of a novel dimeric FcÎłRIIa ectodomain probe. Plasmas were also tested by the use of PF4âheparin IgG ELISA, the HemosIL AcuStar HIT IgGâspecific assay, and a serotonin release assay (SRA).
Results
The dimeric rsFcÎłRIIa test produced no false positives and excluded four samples that were positive by IgG ELISA. In this small patient cohort, the novel assay correctly assigned 93% of the suspected HIT patients, with two of the HIT patients being scored as false negatives. The improved discrimination of the novel assay over the IgG ELISA, which scored four false positives, supports the mechanistic interpretation that binding of dimeric rsFcÎłRIIa detects pairs of closely spaced IgG antibodies in PF4âheparin immune complexes.
Conclusions
This study found the cellâfree, functionâbased dimeric rsFcÎłRIIa assay to be convenient, simple, and potentially predictive of HIT. The assay had improved specificity over the IgG ELISA, and correlated strongly with the AcuStar HIT IgGâspecific assay, warranting further evaluation of its potential to identify HIT in larger patient cohorts
Embodied learning: Responding to AIDS in Lesotho's education sector
This is an Author's Accepted Manuscript of an article published in Children's Geographies, 7(1), 2009. Copyright @ 2009 Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/14733280802630981.In contrast to pre-colonial practices, education in Lesotho's formal school system has historically assumed a Cartesian separation of mind and body, the disciplining of students' bodies serving principally to facilitate cognitive learning. Lesotho has among the highest HIV-prevalence rates worldwide, and AIDS has both direct and indirect impacts on the bodies of many children. Thus, students' bodies can no longer be taken for granted but present a challenge for education. Schools are increasingly seen as a key point of intervention to reduce young people's risk of contracting the disease and also to assist them to cope with its consequences: there is growing recognition that such goals require more than cognitive learning. The approaches adopted, however, range from those that posit a linear and causal relationship between knowledge, attitudes and practices (so-called âKAPâ approaches, in which the role of schools is principally to inculcate the pre-requisite knowledge) to âlife skills programmesâ that advocate a more embodied learning practice in schools. Based on interviews with policy-makers and practitioners and a variety of documentary sources, this paper examines a series of school-based AIDS interventions, arguing that they represent a less radical departure from âeducation for the mindâ than might appear to be the case. The paper concludes that most interventions serve to cast on children responsibility for averting a social risk, and to ânormaliseâ aberrant children's bodies to ensure they conform to what the cognitively-oriented education system expects
The Anatomy of a Magnetar: XMM Monitoring of the Transient Anomalous X-ray Pulsar XTE J1810-197
We present the latest results from a multi-epoch timing and spectral study of
the Transient Anomalous X-ray Pulsar XTE J1810-197. We have acquired seven
observations of this pulsar with the Newton X-ray Multi-mirror Mission
(XMM-Newton) over the course of two and a half years, to follow the spectral
evolution as the source fades from outburst. The spectrum is arguably best
characterized by a two-temperature blackbody whose luminosities are decreasing
exponentially with tau_1 = 870 days and tau_2 = 280 days, respectively. The
temperatures of these components are currently cooling at a rate of 22% per
year from a nearly constant value recorded at earlier epochs of kT_1 = 0.25 keV
and kT_2 = 0.67 keV, respectively. The new data show that the temperature T_1
and luminosity of that component have nearly returned to their historic
quiescent levels and that its pulsed fraction, which has steadily decreased
with time, is now consistent with the previous lack of detected pulsations in
quiescence. We also summarize the detections of radio emission from XTE
J1810-197, the first confirmed for any AXP. We consider possible models for the
emission geometry and mechanisms of XTE J1810-197.Comment: 8 pages, 7 figures, 1 table, latex. To appear in the proceedings of
"Isolated Neutron Stars", Astrophysics & Space Science, in pres
Two-soliton collisions in a near-integrable lattice system
We examine collisions between identical solitons in a weakly perturbed
Ablowitz-Ladik (AL) model, augmented by either onsite cubic nonlinearity (which
corresponds to the Salerno model, and may be realized as an array of strongly
overlapping nonlinear optical waveguides), or a quintic perturbation, or both.
Complex dependences of the outcomes of the collisions on the initial phase
difference between the solitons and location of the collision point are
observed. Large changes of amplitudes and velocities of the colliding solitons
are generated by weak perturbations, showing that the elasticity of soliton
collisions in the AL model is fragile (for instance, the Salerno's perturbation
with the relative strength of 0.08 can give rise to a change of the solitons'
amplitudes by a factor exceeding 2). Exact and approximate conservation laws in
the perturbed system are examined, with a conclusion that the small
perturbations very weakly affect the norm and energy conservation, but
completely destroy the conservation of the lattice momentum, which is explained
by the absence of the translational symmetry in generic nonintegrable lattice
models. Data collected for a very large number of collisions correlate with
this conclusion. Asymmetry of the collisions (which is explained by the
dependence on the location of the central point of the collision relative to
the lattice, and on the phase difference between the solitons) is investigated
too, showing that the nonintegrability-induced effects grow almost linearly
with the perturbation strength. Different perturbations (cubic and quintic
ones) produce virtually identical collision-induced effects, which makes it
possible to compensate them, thus finding a special perturbed system with
almost elastic soliton collisions.Comment: Phys. Rev. E, in pres
Testing the Gaussian expansion method in exactly solvable matrix models
The Gaussian expansion has been developed since early 80s as a powerful
analytical method, which enables nonperturbative studies of various systems
using `perturbative' calculations. Recently the method has been used to suggest
that 4d space-time is generated dynamically in a matrix model formulation of
superstring theory. Here we clarify the nature of the method by applying it to
exactly solvable one-matrix models with various kinds of potential including
the ones unbounded from below and of the double-well type. We also formulate a
prescription to include a linear term in the Gaussian action in a way
consistent with the loop expansion, and test it in some concrete examples. We
discuss a case where we obtain two distinct plateaus in the parameter space of
the Gaussian action, corresponding to different large-N solutions. This
clarifies the situation encountered in the dynamical determination of the
space-time dimensionality in the previous works.Comment: 30 pages, 15 figures, LaTeX; added references for section
Unveiling Soft Gamma-Ray Repeaters with INTEGRAL
Thanks to INTEGRAL's long exposures of the Galactic Plane, the two brightest
Soft Gamma-Ray Repeaters, SGR 1806-20 and SGR 1900+14, have been monitored and
studied in detail for the first time at hard-X/soft gamma rays.
This has produced a wealth of new scientific results, which we will review
here. Since SGR 1806-20 was particularly active during the last two years, more
than 300 short bursts have been observed with INTEGRAL. and their
characteristics have been studied with unprecedented sensitivity in the 15-200
keV range. A hardness-intensity anticorrelation within the bursts has been
discovered and the overall Number-Intensity distribution of the bursts has been
determined. In addition, a particularly active state, during which ~100 bursts
were emitted in ~10 minutes, has been observed on October 5 2004, indicating
that the source activity was rapidly increasing. This eventually led to the
Giant Flare of December 27th 2004, for which a possible soft gamma-ray (>80
keV) early afterglow has been detected.
The deep observations allowed us to discover the persistent emission in hard
X-rays (20-150 keV) from 1806-20 and 1900+14, the latter being in a quiescent
state, and to directly compare the spectral characteristics of all Magnetars
(two SGRs and three Anomalous X-ray Pulsars) detected with INTEGRAL.Comment: 8 pages, 7 figures, Presented at the conference "Isolated Neutron
Stars: from the Surface to the Interior", London, UK, 24-28 April 200
Higher Order Evaluation of the Critical Temperature for Interacting Homogeneous Dilute Bose Gases
We use the nonperturbative linear \delta expansion method to evaluate
analytically the coefficients c_1 and c_2^{\prime \prime} which appear in the
expansion for the transition temperature for a dilute, homogeneous, three
dimensional Bose gas given by T_c= T_0 \{1 + c_1 a n^{1/3} + [ c_2^{\prime}
\ln(a n^{1/3}) +c_2^{\prime \prime} ] a^2 n^{2/3} + {\cal O} (a^3 n)\}, where
T_0 is the result for an ideal gas, a is the s-wave scattering length and n is
the number density. In a previous work the same method has been used to
evaluate c_1 to order-\delta^2 with the result c_1= 3.06. Here, we push the
calculation to the next two orders obtaining c_1=2.45 at order-\delta^3 and
c_1=1.48 at order-\delta^4. Analysing the topology of the graphs involved we
discuss how our results relate to other nonperturbative analytical methods such
as the self-consistent resummation and the 1/N approximations. At the same
orders we obtain c_2^{\prime\prime}=101.4, c_2^{\prime \prime}=98.2 and
c_2^{\prime \prime}=82.9. Our analytical results seem to support the recent
Monte Carlo estimates c_1=1.32 \pm 0.02 and c_2^{\prime \prime}= 75.7 \pm 0.4.Comment: 29 pages, 3 eps figures. Minor changes, one reference added. Version
in press Physical Review A (2002
Distributed fibre-optic monitoring of an Osterberg-cell pile test in London
This paper presents a case study of an Osterberg-cell test of a pile located at the Isle of Dogs in London, which was heavily instrumented with distributed optical-fibre sensors, strain gauges, displacement transducers and extensometers. Special emphasis is given on the data from fibre optics, which offers an advantage due to their spatially continuous nature. The data show a clear development of shaft friction with the applied load and also some unexpected pileâsoil slip within two of the soil layers, which is attributed to the development of a filter cake due to the long construction time. Relevant finite-element analyses are also conducted in an attempt to further understand the mechanisms of pileâsoil slip, which highlight its importance in predicting the vertical displacements. Finally, some comments are included on the observed behaviour of the founding chalk layer. </jats:p
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