O2 : Estudi d'accessibilitat del repositori documental de la UOC

Els repositoris de documents són una font important d'informació per a in­vestigadors, universitaris, docents, i per qualsevol persona que vulgui ac­cedir a informació contrastada sobre qualsevol temàtica. És important que aquesta informació sigui accessible a tothom, i gràcies a Internet s'ha trobat el mitjà vehicular perquè això sigui possible. Ara bé, un cop tenim el mitjà per arribar-­hi, cal que el destí, els programaris contenidors dels repositoris, també siguin accessibles. Amb aquest propòsit, aquest treball recull la informació recaptada de l'avaluació d'una mostra de pàgines del repositori de la UOC. Aquesta avaluació s'ha fet seguint les directrius marcades per la W3C (World Wide Web Consortium), mitjançant el seu grup de treball WAI (Web Accessibility Initiative) i amb la versió 2.0 del recull de directrius WCAG (Web Content Accessibility Guidelines).

Accessibilitat web : un estudi sobre el Repositori O2 de la UOC

Són objectius d'aquest Treball Final de Carrera, en primer lloc, avaluar l'accessibilitat del programari de codi lliure Dspace que utilitza la UOC per gestionar les seves publicacions digitals. En segon lloc, avaluar l'accessibilitat de cinc planes web del Repositori Institucional O2 de la UOC, a les quals s'aplicaran les directrius WCAG 1.0 i WCAG 2.0, amb l'ajut de cinc eines d'avaluació automàtica.

Anà lisi d'accessibilitat WCAG 2.0 del repositori institucional de la UOC (O2)

Estudi sobre repositoris institucionals de documents digitals i anàlisi de 5 pàgines web del repositori institucional de la UOC (O2) en base a la guia d'accessibilitat per a continguts web (WCAG 2.0), que consta de 4 principis, 12 pautes i 61 criteris de conformitat.

Dynamic responses of O2 uptake at the onset and end of exercise in trained subjects.

Inconsistencies about dynamic asymmetry between the on- and off-transient responses in .VO2 are found in the literature. Therefore the purpose of this study was to examine .VO2on- and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (<VT) and heavy (>VT) intensities. .VO2 kinetics in exercise and recovery were better described by a single exponential model (<VT) or by a double exponential with two time delays (>VT). For moderate exercise, we found a symmetry of .VO2 kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (<VT and >VT). Our results do not support a dynamically linear system model of .VO2 during cycling exercise in the heavy-intensity domain.

Addition of inspiratory resistance increases the amplitude of the slow component of O2 uptake kinetics.

The contribution of respiratory muscle work to the development of the O(2) consumption (Vo(2)) slow component is a point of controversy because it has been shown that the increased ventilation in hypoxia is not associated with a concomitant increase in Vo(2) slow component. The first purpose of this study was thus to test the hypothesis of a direct relationship between respiratory muscle work and Vo(2) slow component by manipulating inspiratory resistance. Because the conditions for a Vo(2) slow component specific to respiratory muscle can be reached during intense exercise, the second purpose was to determine whether respiratory muscles behave like limb muscles during heavy exercise. Ten trained subjects performed two 8-min constant-load heavy cycling exercises with and without a threshold valve in random order. Vo(2) was measured breath by breath by using a fast gas exchange analyzer, and the Vo(2) response was modeled after removal of the cardiodynamic phase by using two monoexponential functions. As anticipated, when total work was slightly increased with loaded inspiratory resistance, slight increases in base Vo(2), the primary phase amplitude, and peak Vo(2) were noted (14.2%, P < 0.01; 3.5%, P > 0.05; and 8.3%, P < 0.01, respectively). The bootstrap method revealed small coefficients of variation for the model parameter, including the slow-component amplitude and delay (15 and 19%, respectively), indicating an accurate determination for this critical parameter. The amplitude of the Vo(2) slow component displayed a 27% increase from 8.1 +/- 3.6 to 10.3 +/- 3.4 ml. min(-1). kg(-1) (P < 0.01) with the addition of inspiratory resistance. Taken together, this increase and the lack of any differences in minute volume and ventilatory parameters between the two experimental conditions suggest the occurrence of a Vo(2) slow component specific to the respiratory muscles in loaded condition.

Catálogo de datos oceanográficos (T, S y O2) por estaciones del año en diferentes profundidades frente a la costa peruana, periodo 1970-1985

Tomando como referencia los 0, 50, 100, 200 metros de profundidad promediados por cuadrados Marsden y por estaciones en los años 1970-19785. Se presenta información básica de la temperatura, salinidad y oxígeno en cartas horizontales.

Ab initio study of NOx compounds adsorption on SnO2 surface

An ab initio study of the adsorption processes on NOx compounds on (1 1 0) SnO2 surface is presented with the aim of providing theoretical hints for the development of improved NOx gas sensors. From first principles calculations (DFT¿GGA approximation), the most relevant NO and NO2 adsorption processes are analyzed by means of the estimation of their adsorption energies. The resulting values and the developed model are also corroborated with experimental desorption temperatures for NO and NO2, allowing us to explain the temperature-programmed desorption experiments. The interference of the SO2 poisoning agent on the studied processes is discussed and the adsorption site blocking consequences on sensing response are analyzed.

Effects of erythropoietin on muscle O2 transport during exercise in patients with chronic renal failure.

Erythropoietin (rHuEPO) has proven to be effective in the treatment of anemia of chronic renal failure (CRF). Despite improving the quality of life, peak oxygen uptake after rHuEPO therapy is not improved as much as the increase in hemoglobin concentration ([Hb)] would predict. We hypothesized that this discrepancy is due to failure of O2 transport rates to rise in a manner proportional to [Hb]. To test this, eight patients with CRF undergoing regular hemodialysis were studied pre- and post-rHuEPO ([Hb] = 7.5 +/- 1.0 vs. 12.5 +/- 1.0 g x dl-1) using a standard incremental cycle exercise protocol. A group of 12 healthy sedentary subjects of similar age and anthropometric characteristics served as controls. Arterial and femoral venous blood gas data were obtained and coupled with simultaneous measurements of femoral venous blood flow (Qleg) by thermodilution to obtain O2 delivery and oxygen uptake (VO2). Despite a 68% increase in [Hb], peak VO2 increased by only 33%. This could be explained largely by reduced peak leg blood flow, limiting the gain in O2 delivery to 37%. At peak VO2, after rHuEPO, O2 supply limitation of maximal VO2 was found to occur, permitting the calculation of a value for muscle O2 conductance from capillary to mitochondria (DO2). While DO2 was slightly improved after rHuEPO, it was only 67% of that of sedentary control subjects. This kept maximal oxygen extraction at only 70%. Two important conclusions can be reached from this study. First, the increase in [Hb] produced by rHuEPO is accompanied by a significant reduction in peak blood flow to exercising muscle, which limits the gain in oxygen transport. Second, even after restoration of [Hb], O2 conductance from the muscle capillary to the mitochondria remains considerably below normal.

O2 consumption by the fick method. Methodologic factors.

This study aimed to compare O2 consumption (VO2) determination by the gas-exchange (VO2GE) and Fick (VO2F) methods in cardiac surgical patients. A total of 10 mechanically ventilated postoperative patients were studied prospectively. Thermodilution was performed using three randomly applied techniques: room temperature saline injected at end expiration, room temperature saline randomly injected in the respiratory cycle, and iced saline injected at end expiration. The influence of the number of thermodilution determinations was assessed by comparing results from 2 and 10 injections. The variability of VO2F was greater than that of VO2GE. There was no bias between VO2GE and VO2F values using injectate at room temperature. Accuracy and precision were not improved by increasing the number of cardiac output determinations from 2 to 10. A significant bias was observed using ice-cold injectate, VO2F being 18.0 +/- 15.4 ml/min/m2 lower than VO2GE (p = 0.001). Published results when comparing VO2F and VO2GE are discrepant. However, a significant bias was found in all studies using cold injectate, with lower VO2F values. We conclude that iced injectate should not be used to assess VO2 in critically ill patients.

O2, the Oberta in Open Access : institutional repository

Tríptic informatiu sobre la publicació de documents amb accés obert en el repositori institucional de la UOC, O2 (La Oberta en obert). Aquest informa sobre quins documents hi poden publicar els membres de la comunitat UOC, com fer-ho i els serveis de valor afegit per a tots els usuaris (web 2.0, subscripció per RSS o correu electrònic, exportació al gestor bibliogràfic Refworks, etc.) i per a la recerca (lligam amb l'aplicació d'avaluació de la recerca GIR i informació del factor d'impacte de la revista a SCOPUS, IN-RECS/IN-RECJ i MIAR).

O2, la Oberta en abierto : repositorio institucional

Tríptic informatiu sobre la publicació de documents amb accés obert en el repositori institucional de la UOC, O2 (La Oberta en obert). Aquest informa sobre quins documents hi poden publicar els membres de la comunitat UOC, com fer-ho i els serveis de valor afegit per a tots els usuaris (web 2.0, subscripció per RSS o correu electrònic, exportació al gestor bibliogràfic Refworks, etc.) i per a la recerca (lligam amb l'aplicació d'avaluació de la recerca GIR i informació del factor d'impacte de la revista a SCOPUS, IN-RECS/IN-RECJ i MIAR).

O2, l'Oberta en obert : el repositori institucional

Tríptic informatiu sobre la publicació de documents amb accés obert en el repositori institucional de la UOC, O2 (La Oberta en obert). Aquest informa sobre quins documents hi poden publicar els membres de la comunitat UOC, com fer-ho i els serveis de valor afegit per a tots els usuaris (web 2.0, subscripció per RSS o correu electrònic, exportació al gestor bibliogràfic Refworks, etc.) i per a la recerca (lligam amb l'aplicació d'avaluació de la recerca GIR i informació del factor d'impacte de la revista a SCOPUS, IN-RECS/IN-RECJ i MIAR).

Ventilation, Oxidative Stress, and Nitric Oxide in Hypobaric versus Normobaric Hypoxia.

PURPOSE: Slight differences in physiological responses and nitric oxide (NO) have been reported at rest between hypobaric hypoxia (HH) and normobaric hypoxia (NH) during short exposure.Our study reports NO and oxidative stress at rest and physiological responses during moderate exercise in HH versus NH. METHODS: Ten subjects were randomly exposed for 24 h to HH (3000 m; FIO2, 20.9%; BP, 530 ± 6 mm Hg) or to NH (FIO2, 14.7%; BP, 720 ± 1 mm Hg). Before and every 8 h during the hypoxic exposures, pulse oxygen saturation (SpO2), HR, and gas exchanges were measured during a 6-min submaximal cycling exercise. At rest, the partial pressure of exhaled NO, blood nitrate and nitrite (NOx), plasma levels of oxidative stress, and pH levels were additionally measured. RESULTS: During exercise, minute ventilation was lower in HH compared with NH (-13% after 8 h, P < 0.05). End-tidal CO2 pressure was lower (P < 0.01) than PRE both in HH and NH but decreased less in HH than that in NH (-25% vs -37%, P < 0.05).At rest, exhaled NO and NOx decreased in HH (-46% and -36% after 24 h, respectively, P < 0.05) whereas stable in NH. By contrast, oxidative stress was higher in HH than that in NH after 24 h (P < 0.05). The plasma pH level was stable in HH but increased in NH (P < 0.01). When compared with prenormoxic values, SpO2, HR, oxygen consumption, breathing frequency, and end-tidal O2 pressure showed similar changes in HH and NH. CONCLUSION: Lower ventilatory responses to a similar hypoxic stimulus during rest and exercise in HH versus NH were sustained for 24 h and associated with lower plasma pH level, exaggerated oxidative stress, and impaired NO bioavailability.

FCC-yksikön NOx-päästöjen hallinta

Työssä tutkittiin typen oksidien (NOx) päästöjen muodostumista ja NOx-päästöjen poistomenetelmiä leijukatalyyttisessa krakkausyksikössä (FCC). Koeajossa Porvoon öljynjalostamon FCC-yksikössä tutkittiin NOx-päästöjen hallintaa CO-promoottorin (CO:n palamista edistävä lisäaine) annostelun avulla. Kirjallisuusosassa käsiteltiin NOx-päästöjen muodostumista FCC-yksikön regeneraattorissa. Katalyyttisten lisäaineiden vaikutusta NOx-päästöjen muodostumiseen tarkasteltiin laajasti. Katalyyttisten lisäaineiden ohella käsiteltiin muitakin NOx-päästöjen poistomenetelmiä. Koeajojen tarkoituksena oli optimoida FCC-yksikön katalyyttikiertoon annosteltavan CO-promoottorin määrä. CO-promoottorin sisältämä platina lisää NOx-päästöjen muodostumista regeneraattorissa, mutta vähentää jälkipalamista. Jälkipalamisen vuoksi regeneraattorin ylimenolinjan lämpötila nousee. Regeneraattorin ylimenolinjan lämpötila oli CO-promoottorin vähentämistä rajoittava tekijä, NOx-päästöjä pyrittiin vähentämään ilman merkittävää jälkipalamisen kasvua. Tuorekatalyytin platinapitoisuuden pienentäminen vähentää merkittävästi NOx-päästöjä.