123 research outputs found

    Flat directions, doublet-triplet splitting, the monopole problem, and all that

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    We discuss a supersymmetric SU(6) grand unified theory with the GUT flat direction being lifted by soft supersymmetry breaking, and the doublet-triplet splitting being achieved with Higgs as a pseudo-Goldstone boson. The theory offers a simple solution to the false vacuum and monopole problems.Comment: Latex, 11 pages, no figures. Improved version, more discussion on 1/M_Pl corrections and unwanted relics, new reference

    Measurement of the Running of the Electromagnetic Coupling at Large Momentum-Transfer at LEP

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    The evolution of the electromagnetic coupling, alpha, in the momentum-transfer range 1800GeV^2 < -Q^2 < 21600GeV^2 is studied with about 40000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies 189-209GeV. The running of alpha is parametrised as: alpha(Q^2) = alpha_0/(1-C Delta alpha(Q^2)), where alpha_0=\alpha(Q^2=0) is the fine-structure constant and C=1 corresponds to the evolution expected in QED. A fit to the differential cross section of the e+e- ->e+e- process for scattering angles in the range |cos theta|<0.9 excludes the hypothesis of a constant value of alpha, C=0, and validates the QED prediction with the result: C = 1.05 +/- 0.07 +/- 0.14, where the first uncertainty is statistical and the second systematic

    Situating 1816, the ‘year without summer’, in the UK

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    The immediate local impacts of the eruption of Mount Tambora, Sumbawa, Indonesia in April 1815 were devastating, resulting in the loss of an estimated 60 000 lives on this and neighbouring islands. However, the longer term effects of the largest known historical eruption on global weather and climate and the related consequences for human health and wellbeing have maintained the prominence of the eruption in public memory. Among the most notable effects were global weather anomalies the following year, which has come to be referred to as ‘the year without summer’. Scholars across the sciences and humanities continue to investigate the eruption, seeking insights into the likely meteorological and societal impacts of future volcanic eruptions. The bicentenary of the ‘year without summer’ in 2016 provides a timely moment to revisit this weather episode. In this paper, we draw on a range of archival materials and contemporary publications to reconstruct the weather year and explore how the summer of 1816 was experienced and recorded across the UK. We also wish to demonstrate the importance of historical contingency in understanding the potential implications of the event at the local level, and of situating events within their appropriate temporal context. We do this by considering the summer of 1816 as set against the wider weather and cultural contexts of the 1810s. Our findings illustrate that in a UK context, summer 1816 was characterised by unusual and extreme weather events. Importantly it also took place within a sequence of years that were similarly replete with anomalous and challenging weather conditions

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Sexual Relationships in Hispanic Countries: a Literature Review

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    This is a pre-print of an article published in Current Sexual Health Reports. The final authenticated version is available online at: https://doi.org/10.1007/s11930-020-00272-6Purpose of Review: Sexuality is a complex dimension for which culture seems to play an important role, particularly in countries that are more traditional. This review summarizes the knowledge about sexual relationships in Hispanic countries, considering sexual debut, attitudes, behaviors, and satisfaction. Recent Findings: In line with the literature reviewed, the sexual double standard seems to be continuing to influence sexual relationships. Some countries show more open expressions of sexuality based on the level of gender inequality or sexualized context, and within countries, variables such as religious commitment, family characteristics, and access to resources may play important roles in sexuality. Summary: Future research, policies, and interventions should consider these specific characteristics, including these forms of expression of sexuality, in the adjustment of cross-cultural and cross-national strategies

    Precision tau physics

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    Precise measurements of the lepton properties provide stringent tests of the Standard Model and accurate determinations of its parameters. We overview the present status of tau physics, highlighting the most recent developments, and discuss the prospects for future improvements. The leptonic decays of the tau lepton probe the structure of the weak currents and the universality of their couplings to the W boson. The universality of the leptonic Z couplings has also been tested through Z -> l(+)l(-) decays. The hadronic tau decay modes constitute an ideal tool for studying low-energy effects of the strong interaction in very clean conditions. Accurate determinations of the QCD coupling and the Cabibbo mixing V-us have been obtained with tau data. The large mass of the tau opens the possibility to study many kinematically-allowed exclusive decay modes and extract relevant dynamical information. Violations of flavour and CP conservation laws can also be searched for with tau decays. Related subjects such as μdecays, the electron and muon anomalous magnetic moments, neutrino mixing and B-meson decays into tau leptons are briefly covered. Being one the fermions most strongly coupled to the scalar sector, the tau lepton is playing now a very important role at the LHC as a tool to test the Higgs properties and search for new physics at higher scales

    States Of Discontent

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    Latin America’s recent inclusionary turn centers on changing relationships between the popular sectors and the state. Yet the new inclusion unfolds in a region in which most states are weak and prone to severe pathologies, such as corruption, inefficiency, and particularism. The first part of the chapter outlines an argument, developed at more length elsewhere, regarding how “state crises” helped drive the consolidation of three distinct party system trajectories among the eight South American countries where the Left would eventually win power. The second part of the chapter argues that these trajectories differed in three ways that likely conditioned how the concomitant inclusionary Left turn unfolded in each case: the institutionalization of left-wing parties, the occurrence of state transformation via constitutional reform, and the level of state capacity. The discussion helps highlight the central role of the state and its pathologies in both driving alternative paths of political development and in conditioning the politics of inclusion. By putting the emphasis on the state and its pathologies, we can better consider not just the sources of sociopolitical exclusion but also the limits of sociopolitical inclusion

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Studies of Hadronic Event Structure in e+e- Annihilation from 30 GeV to 209 GeV with the L3 Detector

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    In this Report, QCD results obtained from a study of hadronic event structure in high energy e^+e^- interactions with the L3 detector are presented. The operation of the LEP collider at many different collision energies from 91 GeV to 209 GeV offers a unique opportunity to test QCD by measuring the energy dependence of different observables. The main results concern the measurement of the strong coupling constant, \alpha_s, from hadronic event shapes and the study of effects of soft gluon coherence through charged particle multiplicity and momentum distributions.Comment: To appear in Physics Report
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