7,610 research outputs found
Experimental observation of the 'Tilting Mode' of an array of vortices in a dilute Bose-Einstein Condensate
We have measured the precession frequency of a vortex lattice in a
Bose-Einstein condensate of 87Rb atoms. The observed mode corresponds to a
collective motion in which all the vortices in the array are tilted by a small
angle with respect to the z-axis (the symmetry axis of the trapping potential)
and synchronously rotate about this axis. This motion corresponds to excitation
of a Kelvin wave along the core of each vortex and we have verified that it has
the handedness expected for such helical waves, i.e. precession in the opposite
sense to the rotational flow around the vortices. The experimental method used
to excite this collective mode closely resembles that used to study the
scissors mode and excitation of the scissors mode for a condensate containing a
vortex array was used to determine the angular momentum of the system. Indeed,
the collective tilting of the array that we have observed has previously been
referred to as an `anomalous' scissors mode.Comment: 5 pages, 7 figures to be published in PR
The core structure of presolar graphite onions
Of the ``presolar particles'' extracted from carbonaceous chondrite
dissolution residues, i.e. of those particles which show isotopic evidence of
solidification in the neighborhood of other stars prior to the origin of our
solar system, one subset has an interesting concentric
graphite-rim/graphene-core structure. We show here that single graphene sheet
defects in the onion cores (e.g. cyclopentane loops) may be observable edge-on
by HREM. This could allow a closer look at models for their formation, and in
particular strengthen the possibility that growth of these assemblages proceeds
atom-by-atom with the aid of such in-plane defects, under conditions of growth
(e.g. radiation fluxes or grain temperature) which discourage the graphite
layering that dominates subsequent formation of the rim.Comment: 4 pages, 7 figures, 11 refs, see also
http://www.umsl.edu/~fraundor/isocore.htm
Clinical efficacy, radiographic and safety findings through 2 years of golimumab treatment in patients with active psoriatic arthritis: results from a long-term extension of the randomised, placebo-controlled GO-REVEAL study
Objectives: To assess long-term golimumab efficacy/safety in patients with active psoriatic arthritis (PsA).<p></p>
Methods Adult PsA patients (≥3 swollen, ≥3 tender joints, active psoriasis) were randomly assigned to subcutaneous injections of placebo, golimumab 50â
mg or 100â
mg every 4â
weeks (q4wks) through week 20. All patients received golimumab 50 or 100â
mg beginning week 24. Findings through 2â
years are reported. Efficacy evaluations included ≥20% improvement in American College of Rheumatology (ACR20) response, good/moderate response in Disease Activity Scores incorporating 28 joints and C-reactive protein (DAS28-CRP), ≥75% improvement in Psoriasis Area and Severity Index (PASI75) and changes in PsA-modified Sharp/van der Heijde scores (SHS).<p></p>
Results: Golimumab treatment through 2â
years was effective in maintaining clinical response (response rates: ACR20 63%â70%, DAS28-CRP 77%â86%, PASI75 56%â72%) and inhibiting radiographic progression (mean change in PsA-modified SHS in golimumab-treated patients: â0.36), with no clear difference between doses. No new safety signals were identified through 2â
years. With the study's tuberculosis screening and prophylactic measures, no patient developed active tuberculosis through 2â
years.<p></p>
Conclusions: Golimumab 50 and 100â
mg for up to 2â
years yielded sustained clinical and radiographic efficacy when administered to patients with active PsA. Increasing the golimumab dose from 50 to 100â
mg q4wks added limited benefit. Golimumab safety through up to 2â
years was consistent with other antitumour necrosis factor α agents used to treat PsA. Treatment of patients with latent tuberculosis identified at baseline appeared to be effective in inhibiting the development of active tuberculosis.<p></p>
Growth in densely populated Asia: implications for primary product exporters
Economic growth and integration in Asia is rapidly increasing the global economic importance of the region. To the extent that this growth continues and is strongest in natural resource-poor Asian economies, it will add to global demand for imports of primary products, to the benefit of (especially nearby) resource-abundant countries. How will global production, consumption and trade patterns change by 2030 in the course of such economic developments and structural changes? We address this question using the GTAP model and Version 8.1 of the 2007 GTAP database, together with supplementary data from a range of sources, to support projections of the global economy from 2007 to 2030 under various scenarios. Factor endowments and real gross domestic product are assumed to grow at exogenous rates, and trade-related policies are kept unchanged to generate a core baseline, which is compared with an alternative slower growth scenario. We also consider the impact of several policy changes aimed at increasing China's agricultural self-sufficiency relative to the 2030 baseline. Policy implications for countries of the Asia-Pacific region are drawn out in the final section
Infrared Spectroscopy of Molecular Supernova Remnants
We present Infrared Space Observatory spectroscopy of sites in the supernova
remnants W28, W44, and 3C391, where blast waves are impacting molecular clouds.
Atomic fine-structure lines were detected from C, N, O, Si, P, and Fe. The S(3)
and S(9) lines of H2 were detected for all three remnants. The observations
require both shocks into gas with moderate (~ 100 /cm3) and high (~10,000 /cm3)
pre-shock densities, with the moderate density shocks producing the ionic lines
and the high density shock producing the molecular lines. No single shock model
can account for all of the observed lines, even at the order of magnitude
level. We find that the principal coolants of radiative supernova shocks in
moderate-density gas are the far-infrared continuum from dust grains surviving
the shock, followed by collisionally-excited [O I] 63.2 and [Si II] 34.8 micron
lines. The principal coolant of the high-density shocks is
collisionally-excited H2 rotational and ro-vibrational line emission. We
systematically examine the ground-state fine structure of all cosmically
abundant elements, to explain the presence or lack of all atomic fine lines in
our spectra in terms of the atomic structure, interstellar abundances, and a
moderate-density, partially-ionized plasma. The [P II] line at 60.6 microns is
the first known astronomical detection. There is one bright unidentified line
in our spectra, at 74.26 microns. The presence of bright [Si II] and [Fe II]
lines requires partial destruction of the dust. The required gas-phase
abundance of Fe suggests 15-30% of the Fe-bearing grains were destroyed. The
infrared continuum brightness requires ~1 Msun of dust survives the shock,
suggesting about 1/3 of the dust mass was destroyed, in agreement with the
depletion estimate and with theoretical models for dust destruction.Comment: 40 pages; 10 figures; accepted by ApJ July 11, 200
Thrilled to have âbagged a bargainâ or âbitterâ and âvery frustratingâ? Exploring consumer attitudes to value and deals in tourism
Similar to most global tourism markets, UK consumers adjusted their behavior during the global financial crisis, emphasizing value for money in travel choices. However, there is little evidence concerning consumersâ value-seeking behavior and especially how deals, discounts, and other sales promotions influence tourist decision making. This project explores concepts of value consciousness and deal proneness to shed light on attitudes toward monetary value in travel purchases. Using focus groups, the study found that deals and discounts frequently underpin some tourist choices, but that value consciousness is related to deal proneness, and interactions between the two could result in negative, positive, or mixed emotions. This relationship was captured through a dynamic categorization of touristsâ attitudes and behavior into four approaches to deals and value, namely, deals (1) as a way of life, (2) as a bonus, (3) as a problem, and (4) as toxic. The categories were dynamic in that individuals could move across them. The implications for tourism marketers are outlined
3',5'-Cyclic Adenosine Monophosphate- and Ca2+-Calmodulin-Dependent Endogenous Protein Phosphorylation Activity in Membranes of the Bovine Chromaffin Secretory Vesicles: Identification of Two Phosphorylated Components as Tyrosine Hydroxylase and Protein Kinase Regulatory Subunit Type II
Abstract: Membranes of the secretory vesicles from bovine adrenal medulla were investigated for the presence of the endogenous protein phosphorylation activity. Seven phosphoprotein bands in the molecular weight range of 250,000 to 30,000 were observed by means of the sodium dodecyl sulphate electrophoresis and autoradiography. On the basis of the criteria of molecular weight, selective stimulation of the phosphorylation by cyclic AMP (as compared with cyclic GMP) and immunoprecipitation by specific antibodies, band 5 (molecular weight 60,300) was found to represent the phosphorylated form of the secretory vesicle-bound tyrosine hydroxylase. The electrophoretic mobility, the stimulatory and inhibitory effects of cyclic AMP in presence of Mg2+ and Zn,2+ respectively, and immunoreactivity toward antibodies showed band 6 to contain two forms of the regulatory subunits of the type II cyclic AMP-dependent protein kinase, distinguishable by their molecular weights (56,000 and 52,000, respectively). Phosphorylation of band 7 (molecular weight 29,800) was stimulated about 2 to 3 times by Ca2+ and calmodulin in the concentration range of both agents believed to occur in the secretory tissues under physiological conditions
Clinical Symptoms of Skin, Nails, and Joints Manifest Independently in Patients with Concomitant Psoriasis and Psoriatic Arthritis
This study correlated assessment tools for evaluating the severity of skin, nail, and joint symptoms in patients with psoriasis (Pso) and psoriatic arthritis (PsA). Adults with plaque Pso (with or without PsA) were enrolled from four U.S. institutions. Patients were evaluated using a novel 10-area Linear Psoriasis Area and Severity Index (XL-PASI), Psoriatic Arthritis Assessment (PsAA), Psoriatic Arthritis Screening and Evaluation Questionnaire (PASE), Nail Assessment (NA) and Joint Assessment (JA) tools, Psoriasis Weighted Extent and Severity Index (PWESI), and Lattice Physician Global Assessment (LS-PGA). Correlations between assessment tools and individual items in the assessment tools were performed. Data from 180 patients (55 with PsA) were analyzed. Highest correlations between tools (râ=â0.77â0.88) were between the XL-PASI, PWESI and LS-PGA. Individual items in the XL-PASI correlated with items in the PWESI for extent skin symptoms, but not for all body areas. Overall, correlations were seen between hands and feet, between face and scalp, and between buttocks, chest, and back. Only low correlation was seen between items assessing joint symptoms with items assessing skin symptoms. These data support the notion that the complex phenotype of psoriatic disease requires instruments that assess the severity of skin, nails, and joints separately
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