4,560 research outputs found
Covariant q-differential operators and unitary highest weight representations for U_q su(n,n)
We investigate a one-parameter family of quantum Harish-Chandra modules of
U_q sl(2n). This family is an analog of the holomorphic discrete series of
representations of the group SU(n,n) for the quantum group U_q su(n, n). We
introduce a q-analog of "the wave" operator (a determinant-type differential
operator) and prove certain covariance property of its powers. This result is
applied to the study of some quotients of the above-mentioned quantum
Harish-Chandra modules. We also prove an analog of a known result by J.Faraut
and A.Koranyi on the expansion of reproducing kernels which determines the
analytic continuation of the holomorphic discrete series.Comment: 26 page
Supercooled Liquid Dynamics Studied via Shear-Mechanical Spectroscopy
We report dynamical shear-modulus measurements for five glass-forming liquids
(pentaphenyl trimethyl trisiloxane, diethyl phthalate, dibutyl phthalate,
1,2-propanediol, and m-touluidine). The shear-mechanical spectra are obtained
by the piezoelectric shear-modulus gauge (PSG) method. This technique allows
one to measure the shear modulus ( Pa) of the liquid within a
frequency range from 1 mHz to 10 kHz. We analyze the frequency-dependent
response functions to investigate whether time-temperature superposition (TTS)
is obeyed. We also study the shear-modulus loss-peak position and its
high-frequency part. It has been suggested that when TTS applies, the
high-frequency side of the imaginary part of the dielectric response decreases
like a power law of the frequency with an exponent -1/2. This conjecture is
analyzed on the basis of the shear mechanical data. We find that TTS is obeyed
for pentaphenyl trimethyl trisiloxane and in 1,2-propanediol while in the
remaining liquids evidence of a mechanical process is found. Although
the the high-frequency power law behavior of the shear-loss
may approach a limiting value of when lowering the temperature, we
find that the exponent lies systematically above this value (around 0.4). For
the two liquids without beta relaxation (pentaphenyl trimethyl trisiloxane and
1,2-propanediol) we also test the shoving model prediction, according to which
the the relaxation-time activation energy is proportional to the instantaneous
shear modulus. We find that the data are well described by this model.Comment: 7 pages, 6 figure
Needs and preferences among patients with high-grade glioma and their caregivers - A longitudinal mixed methods study
Ultra-large bandwidth hollow-core guiding in all-silica Bragg fibers with nano-supports
We demonstrate a new class of hollow-core Bragg fibers that are composed of
concentric cylindrical silica rings separated by nanoscale support bridges. We
theoretically predict and experimentally observe hollow-core confinement over
an octave frequency range. The bandwidth of bandgap guiding in this new class
of Bragg fibers exceeds that of other hollow-core fibers reported in the
literature. With only three rings of silica cladding layers, these Bragg fibers
achieve propagation loss of the order of 1 dB/m.Comment: 9 pages including 5 figure
Freshwater flux to Sermilik Fjord, SE Greenland
Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 &plusmn; 4.9&times;10<sup>9</sup> m<sup>3</sup> y<sup>−1</sup> was found (1999–2008), with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier), 11% from terrestrial surface runoff (from melt water and rain), 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 &plusmn; 0.4&times;10<sup>9</sup> m<sup>3</sup> y<sup>−1</sup> in 1999 to 5.9 &plusmn; 0.9&times;10<sup>9</sup> m<sup>3</sup> y<sup>−1</sup> in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations
Diagnostic stability among chronic patients with functional psychoses: an epidemiological and clinical study
<p>Abstract</p> <p>Background</p> <p>Diagnostic stability and illness course of chronic non-organic psychoses are complex phenomena and only few risk factors or predictors are known that can be used reliably. This study investigates the diagnostic stability during the entire course of illness in patients with non-organic psychoses and attempts to identify non-psychopathological risk factors or predictors.</p> <p>Method</p> <p>100 patients with functional psychosis were initially characterised using the Operational Criteria Checklist for Psychotic Illness and Affective Illness (OPCRIT), medical records and health registers. To study the stability of diagnoses (i.e. shifts per time), we used registry data to define four measures of diagnostic variation that were subsequently examined in relation to four possible measures of time (i.e. observation periods or hospitalisation events). Afterwards, we identified putative co-variables and predictors of the best measures of diagnostic stability.</p> <p>Results</p> <p>All four measures of diagnostic variation are very strongly associated with numbers-of-hospitalisations and less so with duration-of-illness, duration-of-hospitalisation and with year-of-first-admission. The four measures of diagnostic variation corrected for numbers-of-hospitalisations were therefore used to study the diagnostic stability. Conventional predictors of illness course – e.g. age-of-onset and premorbid-functioning – are not significantly associated with stability. Only somatic-comorbidity is significantly associated with two measures of stability, while family-history-of-psychiatric-illness and global-assessment-of-functioning (GAF) scale score show a trend. However, the traditional variables age-of-first-admission, civil-status, first-diagnosis-being-schizophrenia and somatic-comorbidity are able to explain two-fifth of the variation in numbers-of-hospitalisations.</p> <p>Conclusion</p> <p>Diagnostic stability is closely linked with the contact between patient and the healthcare system. This could very likely be due to fluctuation of disease manifestation over time or presence of co-morbid psychiatric illness in combination with rigid diagnostic criteria that are unable to capture the multiple psychopathologies of the functional psychoses that results in differential diagnoses and therefore diagnostic instability. Not surprisingly, somatic-comorbidity was found to be a predictor of diagnostic variation thereby being a non-psychiatric confounder.</p
Patterns and localized structures in bistable semiconductor resonators
We report experiments on spatial switching dynamics and steady state
structures of passive nonlinear semiconductor resonators of large Fresnel
number. Extended patterns and switching front dynamics are observed and
investigated. Evidence of localization of structures is given.Comment: 5 pages with 9 figure
HLA class I-redirected anti-tumour CD4+T-cells require a higher TCR binding affinity for optimal activity than CD8+T-cells
CD4+ T helper cells are a valuable component of the immune response towards cancer. Unfortunately, natural tumour-specific CD4+ T-cells occur in low frequency, express relatively low affinity T-cell receptors (TCRs) and show poor reactivity towards cognate antigen. In addition, the lack of human leukocyte antigen (HLA) class II expression on most cancers dictates that these cells are often unable to respond to tumour cells directly. These deficiencies can be overcome by transducing primary CD4+ T-cells with tumour-specific HLA class I-restricted TCRs prior to adoptive transfer. The lack of help from the coreceptor CD8 glycoprotein in CD4+ cells might result in these cells requiring a different optimal TCR binding affinity. Here we compared primary CD4+ and CD8+ T-cells expressing wildtype and a range of affinity-enhanced TCRs specific for the HLA A*0201-restricted NY-ESO-1- and gp100 tumour antigens. Our major findings are: (i) redirected primary CD4+ T-cells expressing TCRs of sufficiently high affinity exhibit a wide range of effector functions, including cytotoxicity, in response to cognate peptide; and, (ii) optimal TCR binding affinity is higher in CD4+ T-cells than CD8+ T-cells. These results indicate that the CD4+ T-cell component of current adoptive therapies using TCRs optimised for CD8+ T-cells is below par and that there is room for substantial improvement. This article is protected by copyright. All rights reserved
Volatile compounds of maari, a fermented product from baobab (Adansonia digitata L.) seeds
The volatile compounds associated with baobab seeds fermentation for Maari production were extracted and analysed by Likens-Nickerson simultaneous steam distillation-extraction method and gas chromatography-mass spectrometry (GC-MS), respectively. Furthermore, the titratable acidity, tannin content and proximate composition were evaluated. A total of 96 compounds were identified with esters, acids, alcohols and ketones being quantitatively the major groups. Fermentation led to an increase in the concentration of total volatile compounds from 121.6 in unfermented cooked seeds to 809.1 mg kg-1 in the fermented product. Drying resulted in a significant loss of up to 80.7% of the total volatiles.Key words: Volatile compounds, maari, baobab, fermentation
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