Anàlisi i disseny estructural d'uns esquís

Aquest treball de final de grau sorgeix d’unir dos dels temes de gran interès per part meva: la resistència de materials i l’esquí. Aquest projecte es centra en el disseny, càlcul, simulació i construcció d’uns esquís. Es realitzaran càlculs teòrics amb els coneixements i conceptes adquirits a les assignatures de Resistència de materials i Ampliació de resistència de materials. La primera part del treball consisteix en un anàlisi i explicació de tots els elements que intervenen en el funcionament, comportament i construcció d’un esquí. Destacant els materials constructius, la seva influència i aportació al comportament d’aquest sobre la neu... així com els diferents mètodes constructius i geometries possibles i com aquestes condicionen la resposta de l’esquí. Finalment es fa un estudi per determinar quines són les forces presents en un esquí quan aquest està sobre la neu en diferents situacions. A la segona part es fa un disseny preliminar de l’esquí segons els criteris de disseny escollits. Se’n determina la geometria, mides, forma... A continuació es fa una selecció dels materials que s’utilitzaran en la construcció de l’esquí, determinant-ne les seves característiques i propietats mecàniques. Seguidament es fa un càlcul dels esforços i tensions presents en l’esquí en les diferents situacions especificades. Aquests càlculs són verificats mitjançant el programari de càlcul ANSYS. Finalment, a la tercera part, es fan algunes optimitzacions pel que fa a materials, i geometria de l’esquí, i, finalment, es porta a terme la seva construcció seguint els criteris i resultats obtinguts al llarg del trebal

Analysis of cooperation in the public goods setting

This is an experimental study aimed to analyze which incentive -punishment or reward-is better at promoting cooperation under the possibility to free-ride in the framework of the financing of public goods. The main tool that has been used to conduct this study is the Public Goods Game experiment with two of its variations. In the first variation, punishment opportunities were allowed and, in the second one, rewarding opportunities were present. This methodology has allowed the comparison of both incentives against each other and against the standard PGG, revealing their weaknesses and advantages. In line with former research, results have verified that individuals, on average, provide levels of contributions halfway the free-riding and the full provision scenario. Also, while both incentives have been able to prevent the decline of cooperation observed in the standard game, punishment has promoted the highest mean contributions and reward the highest mean payoffs. For such reason, it has been far from easy to determine which one is better overall. In conclusion, this study provides evidence that both punishment and reward can succeed at sustaining cooperation in the PGG setting, although reward can be the optimal force at delivering higher payoffs

Superior Electrocatalytic Activity of MoS2-Graphene as Superlattice

[EN] Evidence by selected area diffraction patterns shows the successful preparation of large area (cm x cm) MoS2/graphene heterojunctions in coincidence of the MoS2 and graphene hexagons (superlattice). The electrodes of MoS2/graphene in superlattice configuration show improved catalytic activity for H-2 and O-2 evolution with smaller overpotential of +0.34 V for the overall water splitting when compared with analogous MoS2/graphene heterojunction with random stacking.This research was funded by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-68653-CO2-R1) and Generalitat Valenciana (Prometeo 2017-083).Rendon-Patiño, A.; Domenech-Carbó, A.; Primo Arnau, AM.; García Gómez, H. (2020). Superior Electrocatalytic Activity of MoS2-Graphene as Superlattice. Nanomaterials. 10(5):1-9. https://doi.org/10.3390/nano10050839S1910

A Novel Typing Method for Streptococcus pneumoniae Using Selected Surface Proteins

The diverse pneumococcal diseases are associated with different pneumococcal lineages, or clonal complexes. Nevertheless, intra-clonal genomic variability, which influences pathogenicity, has been reported for surface virulence factors. These factors constitute the communication interface between the pathogen and its host and their corresponding genes are subjected to strong selective pressures affecting functionality and immunogenicity. First, the presence and allelic dispersion of 97 outer protein families were screened in 19 complete pneumococcal genomes. Seventeen families were deemed variable and were then examined in 216 draft genomes. This procedure allowed the generation of binary vectors with 17 positions and the classification of strains into surfotypes. They represent the outer protein subsets with the highest inter-strain discriminative power. A total of 116 non-redundant surfotypes were identified. Those sharing a critical number of common protein features were hierarchically clustered into 18 surfogroups. Most clonal complexes with comparable epidemiological characteristics belonged to the same or similar surfogroups. However, the very large CC156 clonal complex was dispersed over several surfogroups. In order to establish a relationship between surfogroup and pathogenicity, the surfotypes of 95 clinical isolates with different serogroup/serotype combinations were analyzed. We found a significant correlation between surfogroup and type of pathogenic behavior (primary invasive, opportunistic invasive, and non-invasive). We conclude that the virulent behavior of S. pneumoniae is related to the activity of collections of, rather than individual, surface virulence factors. Since surfotypes evolve faster than MLSTs and directly reflect virulence potential, this novel typing protocol is appropriate for the identification of emerging clones.This work was supported by a Miguel Servet contract from the Spanish Ministry of Health to AM, Plan Nacional de I+D+I of the Ministry of Science and Innovation (BIO2011-25343, BIO2014-555462-R, SAF2012-39444-C02), Fondo de Investigaciones Sanitarias de la Seguridad Social (PI11/00763) and Fondo Europeo de Desarrollo Regional (FEDER). CIBER Enfermedades Respiratorias is an initiative of the Instituto de Salud Carlos III.Peer reviewedPeer Reviewe

Proton Motive Force Disruptors Block Bacterial Competence and Horizontal Gene Transfer

Streptococcus pneumoniae is a commensal of the human nasopharynx that can also cause severe antibiotic-resistant infections. Antibiotics drive the spread of resistance by inducing S. pneumoniae competence, in which bacteria express the transformation machinery that facilitates uptake of exogenous DNA and horizontal gene transfer (HGT). We performed a high-throughput screen and identified potent inhibitors of S. pneumoniae competence, called COM-blockers. COM-blockers limit competence by inhibiting the proton motive force (PMF), thereby disrupting export of a quorum-sensing peptide that regulates the transformation machinery. Known chemical PMF disruptors and alterations in pH homeostasis similarly inhibit competence. COM-blockers limit transformation of clinical multi-drug-resistant strains and HGT in infected mice. At their active concentrations, COM-blockers do not affect growth, compromise antibiotic activity, or elicit detectable resistance. COM-blockers provide an experimental tool to inhibit competence and other PMF-involved processes and could help reduce the spread of virulence factors and antibiotic resistance in bacteria. VIDEO ABSTRACT.</p

Invasive pneumococcal disease in healthy adults: increase of empyema associated with the clonal-type Sweden1-ST306

Background: Adult invasive pneumococcal disease (IPD) occurs mainly in the elderly and patients with co-morbidities. Little is known about the clinical characteristics, serotypes and genotypes causing IPD in healthy adults. Methods: We studied 745 culture-proven cases of IPD in adult patients aged 18-64 years (1996-2010). Patients were included in two groups: 1.) adults with co-morbidities, and 2.) healthy adults, who had no prior or coincident diagnosis of a chronic or immunosuppressive underlying disease. Microbiological studies included pneumococcal serotyping and genotyping. Results: Of 745 IPD episodes, 525 (70%) occurred in patients with co-morbidities and 220 (30%) in healthy adults. The healthy adults with IPD were often smokers (56%) or alcohol abusers (18%). As compared to patients with co-morbidities, the healthy adults had (P,0.05): younger age (43.5+/213.1 vs. 48.7+/211.3 years); higher proportions of women (45% vs.24%), pneumonia with empyema (15% vs. 7%) and infection with non-PCV7 serotypes including serotypes 1 (25% vs. 5%), 7F (13% vs. 4%), and 5 (7% vs. 2%); and lower mortality (5% vs. 20%). Empyema was more frequently caused by serotype 1. No death occurred among 79 patients with serotype 1 IPD. There was an emergence of virulent clonal-types Sweden1-ST306 and Netherlands7F-ST191. The vaccine serotype coverage with the PCV13 was higher in healthy adults than in patients with co-morbidities: 82% and 56%, respectively, P,0.001. Conclusion: In this clinical study, one-third of adults with IPD had no underlying chronic or immunosuppressive diseases (healthy adults). They were often smokers and alcohol abusers, and frequently presents with pneumonia and empyema caused by virulent clones of non-PCV7 serotypes such as the Sweden1-ST306. Thus, implementing tobacco and alcohol abuse-cessation measures and a proper pneumococcal vaccination, such as PCV13 policy, in active smokers and alcohol abusers may diminish the burden of IPD in adults

Disease isolates of Streptococcus pseudopneumoniae and non-typeable S. pneumoniae presumptively identified as atypical S. pneumoniae in Spain

We aimed to obtain insights on the nature of a collection of isolates presumptively identified as atypical Streptococcus pneumoniae recovered from invasive and non-invasive infections in Spain. One-hundred and thirty-two isolates were characterized by: optochin susceptibility in ambient and CO2-enriched atmosphere; bile solubility; PCR-based assays targeting pneumococcal genes lytA, ply, pspA, cpsA, Spn9802, aliB-like ORF2, and a specific 16S rRNA region; multilocus sequence analysis; and antimicrobial susceptibility. By multilocus sequence analysis, 61 isolates were S. pseudopneumoniae, 34 were pneumococci, 13 were S. mitis, and 24 remained unclassified as non-pneumococci. Among S. pseudopneumoniae isolates, 51 (83.6%) were collected from respiratory tract samples; eight isolates were obtained from sterile sources. High frequency of non-susceptibility to penicillin (60.7%) and erythromycin (42.6%) was found. Only 50.8% of the S. pseudopneumoniae isolates displayed the typical optochin phenotype originally described for this species. None harbored the cpsA gene or the pneumococcal typical lytA restriction fragment length polymorphism. The Spn9802 and the specific 16S rRNA regions were detected among the majority of the S. pseudopneumoniae isolates (n = 59 and n = 49, respectively). The ply and pspA genes were rarely found. A high genetic diversity was found and 59 profiles were identified. Among the S. pneumoniae, 23 were capsulated and 11 were non-typeable. Three non-typeable isolates, associated to international non-capsulated lineages, were recovered from invasive disease sources. In conclusion, half of the atypical pneumococcal clinical isolates were, in fact, S. pseudopneumoniae and one-fourth were other streptococci. We identified S. pseudopneumoniae and non-typeable pneumococci as cause of disease in Spain including invasive disease