974 research outputs found
Spacelab Charcoal Analyses
This report describes analytical methods and results obtained from chemical analysis of 31 charcoal samples in five sets. Each set was obtained from a single scrubber used to filter ambient air on board a Spacelab mission. Analysis of the charcoal samples was conducted by thermal desorption followed by gas chromatography/mass spectrometry (GC/MS). All samples were analyzed using identical methods. The method used for these analyses was able to detect compounds independent of their polarity or volatility. In addition to the charcoal samples, analyses of three Environmental Control and Life Support System (ECLSS) water samples were conducted specifically for trimethylamine
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Pre-operative psychiatric morbidity in people undergoing cataract surgery.
Background. The aim of our research was to examine the impact of depressive symptomatology and cognitive impairment on visual function and symptoms in patients with cataract. Material and methods. Demographic details, ophthalmological details, Snellen acuity, cataract symptoms, visual function, depressive symptomatology, cognitive impairment and quality of life were measured in 72 elderly subjects attending the pre-assessment cataract clinic at the Herts and Essex Hospital, Bishops Stortford, England. Results. Subjects with depressive symptomatology were significantly more affected by symptoms of cataract (Spearman = 0.039, p<0.05) and had poorer visual functioning (Spearman = 0.023, p<0.05) than their non-depressed counterparts, despite no significant difference in visual acuity between the two groups. There were no significant differences for subjects with cognitive impairment and cataract symptoms (Spearman = 0.700, NS) or visual functioning (Spearman = 0.158, NS). Conclusions. The study supports the hypothesis that depressive symptomatology is related to pre-operative cataract symptoms and visual functioning, but did not confirm that cognitive impairment was related to pre-operative cataract symptoms or level of visual function
Regular dendritic patterns induced by non-local time-periodic forcing
The dynamic response of dendritic solidification to spatially homogeneous
time-periodic forcing has been studied. Phase-field calculations performed in
two dimensions (2D) and experiments on thin (quasi 2D) liquid crystal layers
show that the frequency of dendritic side-branching can be tuned by oscillatory
pressure or heating. The sensitivity of this phenomenon to the relevant
parameters, the frequency and amplitude of the modulation, the initial
undercooling and the anisotropies of the interfacial free energy and molecule
attachment kinetics, has been explored. It has been demonstrated that besides
the side-branching mode synchronous with external forcing as emerging from the
linear Wentzel-Kramers-Brillouin analysis, modes that oscillate with higher
harmonic frequencies are also present with perceptible amplitudes.Comment: 15 pages, 23 figures, Submitted to Phys. Rev.
Narrative exposure therapy for survivors of human trafficking: feasibility randomised controlled trial
Background
Human trafficking is a grave human rights violation and a major public health concern. Survivors present with high rates of mental health problems including post-traumatic stress disorder (PTSD). Studies of effective treatments for PTSD in survivors of human trafficking are lacking. Narrative exposure therapy (NET) is an effective PTSD treatment for multiple, prolonged and complex trauma, but its efficacy has not been rigorously tested in survivors of human trafficking.
Aims
To test the feasibility and acceptability of a randomised controlled trial (RCT) offering NET as a treatment for PTSD in trafficking survivors with a history of multiple traumatic events, as well as providing preliminary evidence regarding its efficacy (trial registration: ISRCTN95136302).
Method
A single-blind RCT compared NET with a wait-list control in survivors of trafficking with PTSD (n = 25). In the NET arm of the study, participants attended a mean of 17 sessions.
Results
NET was well tolerated by participants. There were significant reductions in PTSD, depression and anxiety symptoms post-treatment in the NET group but no significant change in the wait-list group.
Conclusions
The results indicate that NET is a promising and acceptable treatment for trafficking survivors. Psychological therapy in an RCT design can be safely delivered to this vulnerable group, although modifications are required to ensure their holistic needs are properly addressed
Persistent global power fluctuations near a dynamic transition in electroconvection
This is a study of the global fluctuations in power dissipation and light
transmission through a liquid crystal just above the onset of
electroconvection.
The source of the fluctuations is found to be the creation and annihilation
of defects. They are spatially uncorrelated and yet temporally correlated. The
temporal correlation is seen to persist for extremely long times. There seems
to be an especially close relation between defect creation/annihilat ion in
electroconvection and thermal plumes in Rayleigh-B\'enard convection
A molecular basis of analgesic tolerance to cannabinoids
Clinical usage of cannabinoids in chronic pain states is limited by their central side effects and the pharmacodynamic tolerance that sets in after repeated dosage. Analgesic tolerance to cannabinoids in vivo could be caused by agonist-induced downregulation and intracellular trafficking of cannabinoid receptors, but little is known about the molecular mechanisms involved. We show here that the type 1 cannabinoid receptor (CB1) interacts physically with G-protein-associated sorting protein 1 (GASP1), a protein that sorts receptors in lysosomal compartments destined for degradation. CB1 - GASP1 interaction was observed to be required for agonist-induced downregulation of CB1 in spinal neurons ex vivo as well as in vivo. Importantly, uncoupling CB1 from GASP1 in mice in vivo abrogated tolerance toward cannabinoid-induced analgesia. These results suggest that GASP1 is a key regulator of the fate of CB1 after agonist exposure in the nervous system and critically determines analgesic tolerance to cannabinoids
Phase-field model for Hele-Shaw flows with arbitrary viscosity contrast. I. Theoretical approach
We present a phase-field model for the dynamics of the interface between two
inmiscible fluids with arbitrary viscosity contrast in a rectangular Hele-Shaw
cell. With asymptotic matching techniques we check the model to yield the right
Hele-Shaw equations in the sharp-interface limit and compute the corrections to
these equations to first order in the interface thickness. We also compute the
effect of such corrections on the linear dispersion relation of the planar
interface. We discuss in detail the conditions on the interface thickness to
control the accuracy and convergence of the phase-field model to the limiting
Hele-Shaw dynamics. In particular, the convergence appears to be slower for
high viscosity contrasts.Comment: 17 pages in revtex. changes: 1 reference adde
The Current-Temperature Phase Diagram of Layered Superconductors
The behavior of clean layered superconductors in the presence of a finite
electric current and in zero-magnetic field behavior is addressed. The
structure of the current temperature phase diagram and the properties of each
of the four regions will be explained. We will discuss the expected current
voltage and resistance characteristics of each region as well as the effects of
finite size and weak disorder on the phase diagram. In addition, the reason for
which a weakly non-ohmic region exists above the transition temperature will be
explained.Comment: 8 pages (RevTeX), 4 encapsulated postscript figure
3D Lowest Landau Level Theory Applied to YBCO Magnetization and Specific Heat Data: Implications for the Critical Behavior in the H-T Plane
We study the applicability of magnetization and specific heat equations
derived from a lowest-Landau-level (LLL) calculation, to the high-temperature
superconducting (HTSC) materials of the YBaCuO (YBCO)
family. We find that significant information about these materials can be
obtained from this analysis, even though the three-dimensional LLL functions
are not quite as successful in describing them as the corresponding
two-dimensional functions are in describing data for the more anisotropic HTSC
Bi- and Tl-based materials. The results discussed include scaling fits, an
alternative explanation for data claimed as evidence for a second order flux
lattice melting transition, and reasons why 3DXY scaling may have less
significance than previously believed. We also demonstrate how 3DXY scaling
does not describe the specific heat data of YBCO samples in the critical
region. Throughout the paper, the importance of checking the actual scaling
functions, not merely scaling behavior, is stressed.Comment: RevTeX; 10 double-columned pages with 7 figures embedded. (A total of
10 postscript files for the figures.) Submitted to Physical Review
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