20,018 research outputs found
Regulation of transforming growth factor-beta 1 gene expression by glucocorticoids in normal human T lymphocytes.
Glucocorticoids (GC) modulate immune function in a number of ways, including suppression of T cell proliferation and other IL-2-mediated T cell functions. These inhibitory effects are similar to those induced by transforming growth factor-beta 1 (TGF-beta 1), a cytokine with potent T cell inhibiting activities. We examined the hypothesis that GC effects may be at least partially achieved through modulation of the expression of the TGF-beta 1 gene in activated T cells. Normal T cells were cultured with or without purified phytohemagglutinin (PHA-p) and 4 beta-phorbol 12-myristate 13-acetate (PMA) in the presence or absence of the synthetic GC, dexamethasone (100-200 micrograms/ml). The production of latent and active forms of TGF beta by these cells were analyzed by immunoblotting and bioassays. The steady-state levels of TGF-beta 1 mRNA were analyzed in total RNA from these cells by Northern hybridizations using a human TGF-beta 1 cDNA. The results showed that dexamethasone caused an increase in TGF beta production and a dose-dependent two to fourfold increase in TGF-beta 1 mRNA in activated as well as in unstimulated T cells, 1 h after exposure of the cultures to the steroid. The increase in TGF-beta 1 mRNA levels by dexamethasone was further potentiated two to threefold by cycloheximide, suggesting that the steroid effect may be due to inhibition of the synthesis of proteins that decrease TGF-beta 1 gene transcription or the stability of its transcripts. Finally, in vitro nuclear transcription studies indicated the dexamethasone effects on TGF-beta 1 gene expression to be largely transcriptional
ANAEROBIC DIGESTION AS CENTRE OF DAIRY LIVESTOCK AND AGRICULTURE INTEGRATION: BASIS FOR MEDIUM-SCALE CDM PROJECTS DEVELOPMENT
Dairy producers should improve their activity with modern production techniques/technologies to meet the requirements of a stricter consumer market. In this sense, crop and livestock systems integration represents an interesting alternative for using the dairy farm available resources. This paper analyses the use of anaerobic digestion as basis for supplying energy, fertilizers and feed needs of a farming unit, by means of digestion products usage: biogas, which can be used in energy conversion systems to provide the required energy for processing/conservation equipment for milk and other farming products; and effluent, that can be used as a replacement for chemical fertilizers and for aquatic plants/fish feeding. Fossil fuels replacement by biogas can be classified as a Clean Development Mechanism (CDM) project, and economic resources obtained by carbon credits commercialisation may support the required production modernisation. The paper analyses the anaerobic digestion process, evaluating biogas in medium-scale dairy farms, as well as the quantification of carbon credits generated by introducing proper manure and culture remains management
Position-dependent-mass; Cylindrical coordinates, separability, exact solvability, and PT-symmetry
The kinetic energy operator with position-dependent-mass in cylindrical
coordinates is obtained. The separability of the corresponding Schr\"odinger
equation is discussed within radial cylindrical mass settings. Azimuthal
symmetry is assumed and spectral signatures of various z-dependent interaction
potentials (Hermitian and non-Hermitian PT-symmetric) are reported.Comment: 16 page
Quality is in the eye of the stakeholders: what do professional subtitlers and viewers think about subtitling?
Quality is a rather slippery concept, and its assessment in subtitling can be a challenging task, as its appreciation can easily
vary depending on the diferent stakeholders involved in the production and reception of subtitles. In this paper, we evaluate
quality indicators in subtitling as perceived by professional subtitlers and viewers. After exploring the various subtitle
parameters that can have an impact on the quality of the end product (such as line breaks, synchronisation, display rates),
we present the results of two qualitative studies conducted with professional subtitlers and subtitle viewers with diferent
audiovisual backgrounds. The results yield some similarities and discrepancies, particularly in the way in which the strategy
of condensation is perceived by the two groups, and they also help delineate the subtitle parameters that should be taken into
consideration in order to improve the creative process as well as the reception of subtitles
Shearing Interferometer for Quantifying the Coherence of Hard X-Ray Beams
We report a quantitative measurement of the full transverse coherence function of the 14.4 keV x-ray radiation produced by an undulator at the Swiss Light Source. An x-ray grating interferometer consisting of a beam splitter phase grating and an analyzer amplitude grating has been used to measure the degree of coherence as a function of the beam separation out to 30 m. Importantly, the technique provides a model-free and spatially resolved measurement of the complex coherence function and is not restricted to high resolution detectors and small fields of view. The spatial characterization of the wave front has important applications in discovering localized defects in beam line optics
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