Signatures of CP violation in the presence of multiple b-pair production at hadron colliders

We calculate the production of two b-quark pairs in hadron collisions. Sources of multiple pairs are multiple interactions and higher order perturbative QCD mechanisms. We subsequently investigate the competing effects of multiple b-pair production on measurements of CP violation: (i) the increase in event rate with multiple b-pair cross sections which may reach values of the order of 1 b in the presence of multiple interactions and (ii) the dilution of b versus b tagging efficiency because of the presence of events with four B mesons. The impact of multiple B-meson production is small unless the cross section for producing a single pair exceeds 1 mb. We show that even for larger values of the cross section the competing effects (i) and (ii) roughly compensate so that there is no loss in the precision with which CP-violating CKM angles can be determined.

Membrane interaction of polymyxin B and synthetic analogues studied in biomimetic systems: implications for antibacterial action

Membrane-active antimicrobial peptides, such as polymyxin B (PxB), are currently in the spotlight as potential candidates toovercome bacterial resistance. We have designed synthetic analogs ofPxB in order to determine the structural requirements for membraneaction. Since the mechanism of action of PxB involves interaction withboth the outer membrane and the cytoplasmic membrane of Gramnegative bacteria, we have used an approach based on mimicking theouter layers of these membranes using monolayers, Langmuir-Blodgettfilms and unilamelar vesicles, and applying a battery of biophysicalmethods in order to dissect the different events of membraneinteraction. Collectively, results indicate that the PxB analogues act inthe bacterial membrane by the same mechanism than PxB, and that cationic amphipathicity determines peptide activity.

Membrane interaction of polymyxin B and synthetic analogues studied in biomimetic systems: implications for antibacterial action

Membrane-active antimicrobial peptides, such as polymyxin B (PxB), are currently in the spotlight as potential candidates toovercome bacterial resistance. We have designed synthetic analogs ofPxB in order to determine the structural requirements for membraneaction. Since the mechanism of action of PxB involves interaction withboth the outer membrane and the cytoplasmic membrane of Gramnegative bacteria, we have used an approach based on mimicking theouter layers of these membranes using monolayers, Langmuir-Blodgettfilms and unilamelar vesicles, and applying a battery of biophysicalmethods in order to dissect the different events of membraneinteraction. Collectively, results indicate that the PxB analogues act inthe bacterial membrane by the same mechanism than PxB, and that cationic amphipathicity determines peptide activity.

Ancient DNA analysis of 8000 B.C. near eastern farmers supports an early neolithic pioneer maritime colonization of Mainland Europe through Cyprus and the Aegean Islands

The genetic impact associated to the Neolithic spread in Europe has been widely debated over the last 20 years. Within this context, ancient DNA studies have provided a more reliable picture by directly analyzing the protagonist populations at different regions in Europe. However, the lack of available data from the original Near Eastern farmers has limited the achieved conclusions, preventing the formulation of continental models of Neolithic expansion. Here we address this issue by presenting mitochondrial DNA data of the original Near-Eastern Neolithic communities with the aim of providing the adequate background for the interpretation of Neolithic genetic data from European samples. Sixty-three skeletons from the Pre Pottery Neolithic B (PPNB) sites of Tell Halula, Tell Ramad and Dja'de El Mughara dating between 8,700-6,600 cal. B.C. were analyzed, and 15 validated mitochondrial DNA profiles were recovered. In order to estimate the demographic contribution of the first farmers to both Central European and Western Mediterranean Neolithic cultures, haplotype and haplogroup diversities in the PPNB sample were compared using phylogeographic and population genetic analyses to available ancient DNA data from human remains belonging to the Linearbandkeramik-Alföldi Vonaldiszes Kerámia and Cardial/Epicardial cultures. We also searched for possible signatures of the original Neolithic expansion over the modern Near Eastern and South European genetic pools, and tried to infer possible routes of expansion by comparing the obtained results to a database of 60 modern populations from both regions. Comparisons performed among the 3 ancient datasets allowed us to identify K and N-derived mitochondrial DNA haplogroups as potential markers of the Neolithic expansion, whose genetic signature would have reached both the Iberian coasts and the Central European plain. Moreover, the observed genetic affinities between the PPNB samples and the modern populations of Cyprus and Crete seem to suggest that the Neolithic was first introduced into Europe through pioneer seafaring colonization.

'Making Science Understandable'. Divulgació científica i mediació editorial: el cas de The Wisdom of the Body de Walter B. Cannon (1871-1945)

The present paper aims at an historical reconstruction, in the framework of the publishing industry in the years between the two World Wars, of the role played by the publisher William W. Norton in the genesis, published in 1932, and new edition in 1938, of Walter B. Cannon"s book The Wisdom of the Body. With the analysis of this case study, we aimed at contributing to the current criticism of the «dominant view», which tries, in an uncritical manner, that scientific popularization follows an ineluctable, continuous and linear evolution.

'Making Science Understandable'. Divulgació científica i mediació editorial: el cas de The Wisdom of the Body de Walter B. Cannon (1871-1945)

The present paper aims at an historical reconstruction, in the framework of the publishing industry in the years between the two World Wars, of the role played by the publisher William W. Norton in the genesis, published in 1932, and new edition in 1938, of Walter B. Cannon"s book The Wisdom of the Body. With the analysis of this case study, we aimed at contributing to the current criticism of the «dominant view», which tries, in an uncritical manner, that scientific popularization follows an ineluctable, continuous and linear evolution.

Stability and consistency of coping in adolescence: A longitudinal study

This study analyzed stability and consistency of coping among adolescents. The objectives were twofold: a) to analyze temporal stability and cross-situational consistency of coping responses after a 17- month interval, taking into account gender, age and type of stressor. b) To analyze the relative weight of contextual versus dispositional factors in predicting future coping. A cohort of 341 adolescents (51% girls and 49% boys aged between 12 and 16) were assessed twice by means of the Coping Responses Inventory - Youth. The results indicated that the coping responses were quite stable over time at the group level, but with important within-subject differences. Girls showed slightly more stability than boys. Among the girls, Avoidance coping showed as much stability as consistency and Approach coping showed more stability than consistency. Among the boys, Avoidance coping showed more stability than consistency, and Approach coping showed both low stability and low consistency. Among the boys, the coping used at Time 1 barely predicted that used at Time 2; in contrast, among the girls, the type of coping used in the past, especially Avoidance coping, predicted the coping that would be used in the future.

New insights into cellular prion protein (PrPc) functions: the 'ying and yang' of a relevant protein.

The conversion of cellular prion protein (PrPc), a GPI-anchored protein, into a protease-K-resistant and infective form (generally termed PrPsc) is mainly responsible for Transmissible Spongiform Encephalopathies (TSEs), characterized by neuronal degeneration and progressive loss of basic brain functions. Although PrPc is expressed by a wide range of tissues throughout the body, the complete repertoire of its functions has not been fully determined. Recent studies have confirmed its participation in basic physiological processes such as cell proliferation and the regulation of cellular homeostasis. Other studies indicate that PrPc interacts with several molecules to activate signaling cascades with a high number of cellular effects. To determine PrPc functions, transgenic mouse models have been generated in the last decade. In particular, mice lacking specific domains of the PrPc protein have revealed the contribution of these domains to neurodegenerative processes. A dual role of PrPc has been shown, since most authors report protective roles for this protein while others describe pro-apoptotic functions. In this review, we summarize new findings on PrPc functions, especially those related to neural degeneration and cell signaling.