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.

On the number of K3,3-minor-free and maximal K3,3-minor-free graphs

"Vegeu el resum a l'inici del document del fitxer adjunt."

Classical predictive electrodynamics of two charges with radiation: Energy and 3. momentum balance and scattering crossections-II

We deal with a classical predictive mechanical system of two spinless charges where radiation is considered and there are no external fields. The terms (2,2)Paa of the expansion in the charges of the HamiltonJacobi momenta are calculated. Using these, together with known previous results, we can obtain the paa up to the fourth order. Then we have calculated the radiated energy and the 3-momentum in a scattering process as functions of the impact parameter and the incident energy for the former and 3-momentum for the latter. Scattering cross-sections are also calculated. Good agreement with well known results, including those of quantum electrodynamics, has been found.

Teacher training in "multicultural" Sweden

This paper builds on the experience of the on-going, mainly ethnographic, research project called Teacher training in’ multicultural’ Sweden. Class, gender and ethnicity. In this multi-disciplinary project a number of scholars conduct research through participant observation in, and through the study and analysis of documents from, a number of teacher training colleges in Sweden. In this paper I will use empirical material gathered from two teacher training colleges to discuss this basic issue. One college is situated in a suburb outside Stockholm and it consciously portrays itself as a college for ‘multicultural’ students who will later teach in ‘multicultural’ suburbs. The other college is situated in a small town and although ‘multiculturalism’ is seen as important in the educational system students with mainly ‘Swedish’ background are recruited. In the first college ‘differences’ are lauded and students are encouraged to ponder upon and develop their ethnic profile. In the second ‘similarities’ are more taken for granted. I will argue, however, that within these colleges ‘differences’ and ’similarities’ are not only discussed but actually created against a backdrop of macro-constraints which are not much scrutinized within these colleges.

Aplicació web per a gestió de pressuposts a Ncora

El projecte que s’ha presentat correspon a la titulació d’Enginyeria en Informàtica i conté diversos aspectes relacionats al desenvolupament d’una aplicació web per a gestionar els pressupostos de l’empresa Ncora. Es presenta un estudi i anàlisi de requeriments, una compra de servidors, una instal·lació i configuració dels servidors en l’entorn hardware del núvol de Ncora, un anàlisi i disseny de la base de dades i un desenvolupament a mida de l’aplicació software. L’objectiu principal del projecte és l’estalvi de temps en la creació de pressupostos i la ràpida cerca de pressupostos fets així com dels seus components.

Tensión Creativa aplicada al Análisis de Competencias a Alumnos de Ingeniería

This article reflects the analysis of personal and social competences through the study and analysis of creative tensión in engineering students, using a computer application called Cycloid. The main objective was to compare the students' creative tensión by asigning them the task of being the project leader of a given project: their own university major. The process consisted of evaluating, through special surveys, a group of students to know the current situation of competences, using fuzzy logic analysis. From this self-knowledge, provided by the survey, students can know their strong and weak characteristics regarding their study habits. Results showed that tolerance to stress and to language courses are the weaker points. This application is useful for the design of study strategies that students themselves can do to better face their courses

Conjugation of genetically-engineered protein phosphatases to magnetic particles for okadaic acid detection

This work presents the functional characterisation of a protein phosphatase 2A (PP2A) catalytic subunit obtained by genetic engineering and its conjugation to magnetic particles (MPs) via metal coordination chemistry for the subsequent development of assays for diarrheic lipophilic marine toxins. Colorimetric assays with free enzyme have allowed the determination of the best enzyme activity stabiliser, which is glycerol at 10%. They have also demonstrated that the recombinant enzyme can be as sensitive towards okadaic acid (OA) (LOD=2.3μg/L) and dinophysistoxin-1 (DTX-1) (LOD=15.2μg/L) as a commercial PP2A and, moreover, it has a higher operational stability, which makes possible to perform the protein phosphatase inhibition assay (PPIA) with a lower enzyme amount. Once conjugated to MPs, the PP2A catalytic subunit still retains its enzyme activity and it can also be inhibited by OA (LOD=30.1μg/L).

El discurs polític: la immigració com a pretext

El treball és una d’anàlisi del discurs polític que apareix en els programes electorals dels candidats a les presidencials franceses 2012, centrant l’atenció en el terme immigration. L’objectiu és identificar de quina manera expressen la seva ideologia, concretar les semblances, les divergències i els matisos que determinen en els seus discursos.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.

Statistical Reviewers Improve Reporting in Biomedical Articles: a Randomized Trial.

Background. Although peer review is widely considered to be the most credible way of selecting manuscripts and improving the quality of accepted papers in scientific journals, there is little evidence to support its use. Our aim was to estimate the effects on manuscript quality of either adding a statistical peer reviewer or suggesting the use of checklists such as CONSORT or STARD to clinical reviewers or both. Methodology and Principal Findings. Interventions were defined as 1) the addition of a statistical reviewer to the clinical peer review process, and 2) suggesting reporting guidelines to reviewers; with"no statistical expert" and"no checklist" as controls. The two interventions were crossed in a 262 balanced factorial design including original research articles consecutively selected, between May 2004 and March 2005, by the Medicina Clinica (Barc) editorial committee. We randomized manuscripts to minimize differences in terms of baseline quality and type of study (intervention, longitudinal, cross-sectional, others). Sample-size calculations indicated that 100 papers provide an 80% power to test a 55% standardized difference. We specified the main outcome as the increment in quality of papers as measured on the Goodman Scale. Two blinded evaluators rated the quality of manuscripts at initial submission and final post peer review version. Of the 327 manuscripts submitted to the journal, 131 were accepted for further review, and 129 were randomized. Of those, 14 that were lost to follow-up showed no differences in initial quality to the followed-up papers. Hence, 115 were included in the main analysis, with 16 rejected for publication after peer review. 21 (18.3%) of the 115 included papers were interventions, 46 (40.0%) were longitudinal designs, 28 (24.3%) cross-sectional and 20 (17.4%) others. The 16 (13.9%) rejected papers had a significantly lower initial score on the overall Goodman scale than accepted papers (difference 15.0, 95% CI: 4.6- 24.4). The effect of suggesting a guideline to the reviewers had no effect on change in overall quality as measured by the Goodman scale (0.9, 95% CI: 20.3+2.1). The estimated effect of adding a statistical reviewer was 5.5 (95% CI: 4.3-6.7), showing a significant improvement in quality. Conclusions and Significance. This prospective randomized study shows the positive effect of adding a statistical reviewer to the field-expert peers in improving manuscript quality. We did not find a statistically significant positive effect by suggesting reviewers use reporting guidelines.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.

Empirical welfare analysis: when preferences matter

Fleurbaey and Maniquet have proposed the criteria of conditional equality and of egalitarian equivalence to assess the equity among individuals in an ordinal setting. Empirical applications are rare and only partially consistent with their framework. We propose a new empirical approach that relies on individual preferences, is consistent with the ordinal criteria and enables to compare them with the cardinal criteria. We estimate a utility function that incorporates individual heterogeneous preferences, obtain ordinal measures of well-being and apply conditional equality and egalitarian equivalence. We then propose two cardinal measures of well-being, that are comparable with the ordinal model, to compute Roemer’s and Van de gaer’s criteria. Finally we compare the characteristics of the worst-off displayed by each criterion. We apply this model to a sample of US micro data and obtain that about 18% of the worst-off are not common to all criteria.