Search results for "DOP"
showing 10 items of 4870 documents
Attitudes and perceptions of faculty members in the process adopting innovation: The OpenCourseWare initiative at the University of Valencia, Spain
2014
The OpenCourseWare project, an open learning resource repository, was established at the University of Valencia between 2008 and2009. It initially consisted of only 10 subjects, none of which was in the field of Health Sciences. The objective of this research was toinvestigate the attitudes and perceptions of faculty members in the field of Health Sciences with regard to the project to identify strategies to increase its use and expand its coverage. We applied Rogers’ innovation-diffusion theory along with a qualitative approach using theoretical sampling, semi-structured interviews and open coding. The results indicate the existence of two categories of faculty members. In the first group,…
Influence of ventral tegmental area (A10 region) on flight behaviour elicited by hypothalamic stimulation in the cat.
1993
The influence of the ventral tegmental area (VTA) (dopaminergic A10 group neurons) on flight behaviour, induced by hypothalamic stimulation, was studied in the cat. Co-stimulation of hypothalamus and VTA (ipsi- or contralateral) induced an increase of the flight latency. Slow-motion analysis of flight behaviour showed that this increase was due to the augmentation of the fixation latency (FL) whereas the upright latency (UL) was not modified. Sulpiride injection (50 mg/kg i.p.) provoked the disappearance of VTA effect without affecting the basal behavioural sequence. The results show that DA A10 group neurons increase the attentive component of the flight reaction, suggesting a possible inf…
Antidoping Science
2018
The ineffectiveness of antidoping programs in elite sport, largely due to human and political factors, is leading to a new resolve and greater transparency of antidoping authorities and those stakeholders interested in drug-free sport. The perception by the public, athletes, and the World Anti-Doping Agency (WADA) of antidoping science and current drug testing programs in elite sport varies widely from "ineffective" to "robust and reliable." Here, we discuss why a careful and considered reevaluation of the underlying premise of antidoping science is needed to bring this unique application of predictive/diagnostic science more in line with other areas of medicine. We show how the validity of…
Synthesis and Characterization of Iron-Doped ZrSiO4 Solid Solutions from Gels
2011
The mechanism of formation and the structural features of tetragonal Fe–ZrO2-amorphous silica composites and particulated Fe-doped ZrSiO4 solid solutions were studied. A series of specimens with compositions Fex–ZrSiO4, 0 ≤ x ≤ 0.10 were prepared by sol–gel techniques and thermally annealed over the range of temperature between 400°C and 1600°C. Results confirmed the formation of tetragonal Fe–ZrO2 solid solution as first crystalline phase on the whole process leading to Fe-doped ZrSiO4 solid solution. The annealing temperature for the preparation of Fe-containing ZrSiO4 solid solutions was dependent on the nominal amount of iron. The Fex–ZrSiO4 solid solutions, with 0.02 < x < 0.08, were a…
Transition metal ions luminescence in neutron irradiated magnesium oxide
2010
The results of investigation of the photoluminescence (PL), its excitation and optical absorption of MgO crystals doped with different concentrations of transition metals exposed to fast neutron irradiation and after annealing are presented. It is suggested that the 440 nm photoluminescence band belongs to the complex V−OH-Fe3+ center with tetragonal symmetry, the ~730 nm PL band observed in the irradiated MgO crystals is connected with defects, generated as a result of decay of the complex V−OH-Fe3+ centers. The near infrared luminescence bands in MgO crystals are connected with Fe3+-Fe3+ exchange coupled pairs.
2-Hydroxyoleic Acid Induces ER Stress and Autophagy in Various Human Glioma Cell Lines
2012
Background: 2-Hydroxyoleic acid is a synthetic fatty acid with potent anti-cancer activity which does not induce undesired side effects. However, the molecular and cellular mechanisms by which this compound selectively kills human glioma cancer cells without killing normal cells is not fully understood. The present study was designed to determine the molecular bases underlying the potency against 1321N1, SF-767 and U118 human glioma cell lines growth without affecting non cancer MRC-5 cells. Methodology/Principal Findings: The cellular levels of endoplasmic reticulum (ER) stress, unfolded protein response (UPR) and autophagy markers were determined by quantitative RT-PCR and immunoblotting …
Protective effect of paraoxonase-2 against endoplasmic reticulum stress-induced apoptosis is lost upon disturbance of calcium homoeostasis
2008
PON2 (paraoxonase-2) is a ubiquitously expressed antioxidative protein which is largely found in the ER (endoplasmic reticulum). Addressing the cytoprotective functions of PON2, we observed that PON2 overexpression provided significant resistance to ER-stress-induced caspase 3 activation when the ER stress was induced by interference with protein modification (by tunicamycin or dithiothreitol), but not when ER stress was induced by disturbance of Ca2+ homoeostasis (by thapsigargin or A23187). When analysing the underlying molecular events, we found an activation of the PON2 promoter in response to all tested ER-stress-inducing stimuli. However, only tunicamycin and dithiothreitol resulted i…
Modulation of intracellular calcium concentrations and T cell activation by prickly pear polyphenols.
2004
Opuntia ficus indica (prickly pear) polyphenolic compounds (OFPC) triggered an increase in [Ca2+]i in human Jurkat T-cell lines. Furthermore, OFPC-induced rise in [Ca2+]i was significantly curtailed in calcium-free buffer (0% Ca2+) as compared to that in 100% Ca2+ medium. Preincubation of cells with tyrphostin A9, an inhibitor of Ca2+ release-activated Ca2+ (CRAC) channels, significantly diminished the OFPC-induced sustained response on the increases in [Ca2+]i. Lanthanum and nifedipine, the respective inhibitors of voltage-dependent and L-type calcium channels, failed to curtail significantly the OFPC-induced calcium response. As OFPC still stimulated increases in [Ca2+]i in 0% Ca2+ medium…
Regulation of calcium signalling by docosahexaenoic acid in human T-cells: implication of CRAC channels
2000
Abstract We elucidated the role of docosahexaenoic acid (DHA) on the increases in free intracellular calcium concentrations, [Ca2+]i, in human (Jurkat) T-cell lines. DHA evoked an increase in [Ca2+]i in a dose-dependent manner in these cells. Anti-CD3 antibody, known to stimulate increases in Ca2+ from endoplasmic reticulum (ER) via the production of inositol trisphosphate, also evoked increases in [Ca2+]i in Jurkat T-cells. We also used thapsigargin which inhibits Ca2+-ATPase of the ER and, therefore, increases Ca2+ in the cytosol. Interestingly, addition of DHA during the thapsigargin-induced peak response exerted an additive effect on the increases in [Ca2+]i in human T-cells, indicating…
Role of three isoforms of phospholipase A2in capacitative calcium influx in human T-cells
2002
The present study was conducted on human Jurkat T-cell lines in order to elucidate the role of phospholipase A2 in capacitative calcium entry. We have employed thapsigargin (TG) that induces increases in [Ca2+]i by emptying the calcium pool of endoplasmic reticulum, followed by capacitative calcium entry. We designed a Ca2+ free/Ca2+ reintroduction (CFCR) protocol for the experiments, conducted in Ca2+-free medium. By employing CFCR protocol, we observed that addition of exogenous arachidonic acid (AA) stimulated TG-induced capacitative calcium influx. The liberation of endogenous AA and its autocrine action seems to be implicated during TG-induced capacitative calcium influx: TG potentiate…