Estimating arterial blood gases with the EABC® System (“Earlobe Arterialized Blood Collector”) in critically ill patients. A validation study.

The Earlobe Arterialized Blood Collector® is a minimally invasive system able to perform arterialized capillary blood gas analysis from the earlobe (EL). A prospective validation study was performed in 55 critical ill patients. Sampling failure rate was high (53.6%). Risk factors were age > 65 years, diabetes, vasoactive drug therapy and noradrenaline (NA) doses above 0.22 μg / kg / min. Multivariate analysis showed age > 65 years was the only factor independently associated with failure. Concordance analysis with arterial blood gases and Bland-Altman agreement evaluation were insufficient for validating the new system for all gasometrical variables.

Stratification of the severity of critically ill patients with classification trees

Background: Development of three classification trees (CT) based on the CART (Classification and Regression Trees), CHAID (Chi-Square Automatic Interaction Detection) and C4.5 methodologies for the calculation of probability of hospital mortality; the comparison of the results with the APACHE II, SAPS II and MPM II-24 scores, and with a model based on multiple logistic regression (LR). Methods: Retrospective study of 2864 patients. Random partition (70:30) into a Development Set (DS) n = 1808 and Validation Set (VS) n = 808. Their properties of discrimination are compared with the ROC curve (AUC CI 95%), Percent of correct classification (PCC CI 95%); and the calibration with the Calibration Curve and the Standardized Mortality Ratio (SMR CI 95%). Results: CTs are produced with a different selection of variables and decision rules: CART (5 variables and 8 decision rules), CHAID (7 variables and 15 rules) and C4.5 (6 variables and 10 rules). The common variables were: inotropic therapy, Glasgow, age, (A-a)O2 gradient and antecedent of chronic illness. In VS: all the models achieved acceptable discrimination with AUC above 0.7. CT: CART (0.75(0.71-0.81)), CHAID (0.76(0.72-0.79)) and C4.5 (0.76(0.73-0.80)). PCC: CART (72(69- 75)), CHAID (72(69-75)) and C4.5 (76(73-79)). Calibration (SMR) better in the CT: CART (1.04(0.95-1.31)), CHAID (1.06(0.97-1.15) and C4.5 (1.08(0.98-1.16)). Conclusion: With different methodologies of CTs, trees are generated with different selection of variables and decision rules. The CTs are easy to interpret, and they stratify the risk of hospital mortality. The CTs should be taken into account for the classification of the prognosis of critically ill patients.

A proof that all Seifert 3-manifold groups and all virtual surface groups are conjugacy separable

We prove that the fundamental group of any Seifert 3-manifold is conjugacy separable. That is, conjugates may be distinguished infinite quotients or, equivalently, conjugacy classes are closed in the pro-finite topology.

Not all university degrees yield the same return: private and social returns to higher education for males in Spain

In this paper we use micro data from the Spanish Family Expenditure Survey for 1990 to estimate, for the first time, the private and social rates of return of different university degrees in Spain. We compute internal rates of return and include investment on higher education financed by the public purse to estimate social rates of return. Our main finding is that, as presumed, there is large heterogeneity in rates of return amongst different university

1st National Accessiblity Plan 2004-2012: achieving equal opportunities and full participation through design for all

According to official statistics, disabled people in Spain number 3.5 million and make up 8.8% of the Spanish population. This group of people are increasingly being recognised as members of society with equal rights, and many of their demands are gradually being transformed into solutions that benefit society as a whole. One example is improved accessibility. Accessible built environments are more human and inclusive places, as well as being easier to get around. Improved accessibility is now recognised as a requirement shared by all members of society, although it is achieved thanks to the demands of disabled people and their representatives. The 1st National Accessibility Plan is a strategic framework for action aimed at ensuring that new products, services and built environments are designed to be accessible for as many people as possible (Design for All) and that existing ones are gradually duly adapted.

All-pay auction equilibria in contests

We analyze (non-deterministic) contests with anonymous contest success functions. There is no restriction on the number of contestants or on their valuations for the prize. We provide intuitive and easily verifiable conditions for the existence of an equilibrium with properties similar to the one of the (deterministic) all-pay auction. Since these conditions are fulfilled for a wide array of situations, the predictions of this equilibrium are very robust to the specific details of the contest. An application of this result contributes to fill a gap in the analysis of the popular Tullock rent- seeking game because it characterizes properties of an equilibrium for increasing returns to scale larger than two, for any number of contestants and in contests with or without a common value. Keywords: (non-) deterministic contest, all-pay auction, contest success functions. JEL Classification Numbers: C72 (Noncooperative Games), D72 (Economic Models of Political Processes: Rent-Seeking, Elections), D44 (Auctions).

In Search of a theory of debt management

A growing literature integrates theories of debt management into models of optimal fiscal policy. One promising theory argues that the composition of government debt should be chosen so that fluctuations in the market value of debt offset changes in expected future deficits. This complete market approach to debt management is valid even when the government only issues non-contingent bonds. A number of authors conclude from this approach that governments should issue long term debt and invest in short term assets. We argue that the conclusions of this approach are too fragile to serve as a basis for policy recommendations. This is because bonds at different maturities have highly correlated returns, causing the determination of the optimal portfolio to be ill-conditioned. To make this point concrete we examine the implications of this approach to debt management in various models, both analytically and using numerical methods calibrated to the US economy. We find the complete market approach recommends asset positions which are huge multiples of GDP. Introducing persistent shocks or capital accumulation only worsens this problem. Increasing the volatility of interest rates through habits partly reduces the size of these simulations we find no presumption that governments should issue long term debt ? policy recommendations can be easily reversed through small perturbations in the specification of shocks or small variations in the maturity of bonds issued. We further extend the literature by removing the assumption that governments every period costlessly repurchase all outstanding debt. This exacerbates the size of the required positions, worsens their volatility and in some cases produces instability in debt holdings. We conclude that it is very difficult to insulate fiscal policy from shocks by using the complete markets approach to debt management. Given the limited variability of the yield curve using maturities is a poor way to substitute for state contingent debt. The result is the positions recommended by this approach conflict with a number of features that we believe are important in making bond markets incomplete e.g allowing for transaction costs, liquidity effects, etc.. Until these features are all fully incorporated we remain in search of a theory of debt management capable of providing robust policy insights.

Label Space Reduction in All-Optical Label Switchiing Networks

Report for the scientific sojourn at the Department of Information Technology (INTEC) at the Ghent University, Belgium, from january to june 2007. All-Optical Label Swapping (AOLS) forms a key technology towards the implementation of All-Optical Packet Switching nodes (AOPS) for the future optical Internet. The capital expenditures of the deployment of AOLS increases with the size of the label spaces (i.e. the number of used labels), since a special optical device is needed for each recognized label on every node. Label space sizes are affected by the wayin which demands are routed. For instance, while shortest-path routing leads to the usage of fewer labels but high link utilization, minimum interference routing leads to the opposite. This project studies and proposes All-Optical Label Stacking (AOLStack), which is an extension of the AOLS architecture. AOLStack aims at reducing label spaces while easing the compromise with link utilization. In this project, an Integer Lineal Program is proposed with the objective of analyzing the softening of the aforementioned trade-off due to AOLStack. Furthermore, a heuristic aiming at finding good solutions in polynomial-time is proposed as well. Simulation results show that AOLStack either a) reduces the label spaces with a low increase in the link utilization or, similarly, b) uses better the residual bandwidth to decrease the number of labels even more.

Más allá de la ley de May: disparidades curvilíneas y conflicto intrapartidista. El caso de Cataluña

Este artículo pretende contribuir al debate sobre el papel que desempeñan los adherentes y activistas y, de modo especial, a intentar plantear de nuevo el problema de su influencia dentro del partido. Para ello se revisa el trabajo de May (1973), sus posteriores desarrollos empíricos, y se intenta comprobar su validez en los principales ejes que marcan la competencia política catalana. Una vez comprobada la existencia de disparidades ideológicas en el caso catalán, el papel se centra en discutir algunas de las limitaciones del modelo de May. Ello permite, a su vez, sugerir la necesidad de elaborar un nuevo modelo de conflicto partidista que tenga presente tanto las relaciones de poder verticales (entre dirigentes y activistas) como horizontales (entre los mismos dirigentes). Para mostrar empíricamente las debilidades señaladas en el modelo de May, el análisis termina con un caso estudio que intenta ilustrar la dificultad de asociar disparidades con conflicto interno.

Lovemarks: lealtad más allá de la razón

El present treball és un estudi a nivell global i individual sobre marques, i especialment les lovemarks, i els diferents vincles emocionals que motiven i impulsen el culte de determinats béns i serveis. L’estudi està enfocat a dos nivells: el del consumidor i el dels planificadors estratègics de marca.

Más allá de los blogs personales: el periodismo participativo en la prensa electrónica

La irrupció d’Internet i les Noves Tecnologies, juntament amb una sèrie de factors socials, polítics i econòmics, han redefinit la clàssica relació unidireccional entre els mitjans i les seves audiències. En aquest context de democratització informativa, el tradicional monopoli dels mitjans ha desaparegut en pro d’un accés i una participació més gran dels lectors a la informació. Aquesta nova modalitat periodística, denominada Periodisme Participatiu o 2.0, promou tota una sèrie de canals o vies de comunicació -xats, fòrums, enquestes, entrevistes, lectors informadors etc.- que ofereixen a l’usuari la possibilitat de convertir-se en receptors i emissors de les noticies alhora. Aquesta intervenció activa de les audiències en el procés informatiu ha alterat, irremediablement, els patrons de consum informatiu i la naturalesa del periodisme tradicional

Narraciones más allá del canon. El caso de Leni Riefenstahl

L'objectiu d'aquest treball s'articula dins de l'anàlisi estètic e històric de la concepció del cos humà i del seu cànon a partir del nexe que relaciona, el Classicisme Greco–romà i l'imaginari del Nazisme. En aquest sentit, la producció de Leni Riefenstahl –la mirada del Nacionalsocialisme– es vital per entendre el desenvolupament de tal nexe; i la nostra intenció ha estat articular un discurs intercomunicatiu entre ambdós imaginaris.

Reduction in catheter-related bloodstream infections in critically ill patients through a multiple system intervention.

Els catéters venosos centrals són necessaris per al maneig del pacient crític però poden ser l´origen d´una bacteriemia. Aquest estudi prospectiu de cohort té com a objectiu determinar la utilitat de l´aplicació d´unes mesures bàsiques de prevenció per disminuir la incidència de bacteriemia associada a catéter. Els resultats de l´estudi confirmen que l´aplicació d´aquest sistema d´intervenció múltiple basat en l´evidencia redueix de forma significativa les bacteriemies associades a catéter a la nostra UCI.

Más allá de una distinción dicotómica del apoyo a la democracia: diversos perfiles de no demócratas

El apoyo ciudadano a la democracia constituye un requisito fundamental de los modernos regímenes democráticos, tanto respecto de su estabilidad y consolidación como de la calidad de su funcionamiento. En este marco, la legitimidad democrática pertenece a la dimensión de creencias ciudadanas respecto de que la democracia y sus instituciones son las más apropiadas (de hecho, las únicas aceptables) como régimen de gobierno. Sin perjuicio de lo anterior, no todos los ciudadanos expresan este conjunto de actitudes positivas hacia el régimen democrático. En gran parte de las nuevas democracias un número considerable de personas o bien no entregan un apoyo abierto a la democracia o, expresan actitudes contradictorias hacia los regímenes democráticos. Este grupo de individuos ha sido normalmente tratado por la literatura como un solo grupo homogéneo, que responde sin más consideraciones a la etiqueta de “no demócratas”. Sin embargo, tal como esta investigación pretende demostrar, existen razones teóricas y empíricas para esperar que no haya un único perfil de ciudadanos que no apoya la democracia. Por el contrario, sería posible encontrar y analizar diversos perfiles de “no demócratas”, que explican sus diferencias de acuerdo a distintas objeciones hacia la democracia. Esto es, las razones que se tienen para no entregar un apoyo difuso a la democracia no serían las mismas en todos los casos. De esta forma se derivan las siguientes preguntas de investigación: ¿Cuáles son los argumentos teóricos y empíricos que permiten distinguir diversos tipos de “no demócratas”? ¿Cuáles son las distintas objeciones hacia la democracia (razones) que configuran estos perfiles diversos? Sin embargo, no basta con responder sólo a estas preguntas. Es necesario avanzar en esta línea argumental, preguntándose respecto de la relevancia de distinguir distintos perfiles de “no demócratas”. Así, surge una tercera pregunta: ¿Bajo qué circunstancias tiene relevancia efectuar una distinción entre quienes no apoyan la democracia?

Analitzador del tràfic de Xarxa per entorn Linux 'Sniff All'

L'objectiu d'aquest treball de final de carrera és clar pel que fa a la funcionalitat: es tracta de fer un analitzador de xarxa (vulgarment conegut com a detector) que funcioni en entorns Linux i amb interfícies d'usuari gràfiques.