5,148 research outputs found

    Possible experimental signatures at the LHC of strongly interacting electro-weak symmetry breaking

    Get PDF
    If electro-weak symmetry is broken by a new strongly interacting sector, new physics will probably manifest itself in gauge boson scattering at the LHC. The relevant dynamics is well described in terms of an effective lagrangian. We discuss the probable size of the coefficients of the relevant operators under a combination of model-independent constraints and reasonable assumptions based on two models of the strongly interacting sector. We compare these values with LHC sensitivity and argue that they will be too small to be seen. Therefore, the presence of vector and scalar resonances required by unitarity will be the only characteristic signature. We analyze the most likely masses and widths of these resonances.Comment: 14 pages, pdftex, 5 figures, improved discussion of bounds, 1 footnote remove

    On the stability of thick brane worlds non-minimally coupled to gravity

    Full text link
    We analyze a class of 5D models where a 3 brane is generated by a bulk scalar field non minimally coupled to gravity. We show that perturbative stability of such branes is normally guaranteed although non minimal couplings are not innocuous in general. After the physical states are identified the linearized equations for propagating modes are evaluated into a Schroedinger form and supersymmetric quantum mechanics provides the absence of tachyons. The spectrum contains a tower of spin 2 and spin 0 fields with continuous masses starting from zero ones. For regular geometries the scalar spectrum contains a state with zero mass which is always non normalizable. The propagating massive scalar states are repelled off the brane due to a centrifugal potential.Comment: 15 page

    The bearable compositeness of leptons

    Get PDF
    Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charged lepton flavor and CP violating observables. We put forward a U(1)3 × CP symmetry of the composite sector, in order to allow the new physics to be not far above the TeV scale. This hypothesis effectively suppresses the new contributions to the electron EDM and μ → eγ, by far the most constraining observables, and results in a novel pattern of flavor violation and neutrino masses. The CP violation in the elementary-composite mixing is shown to induce a CKM phase of the correct size, as well as order-one phases in the PMNS matrix. We compare with the alternative possibility of introducing multiple scales of compositeness for leptons, that also allow to evade flavor and CP constraints. Finally, we examine violations of lepton flavor universality in B-meson semi-leptonic decays. The neutral-current anomalies can be accommodated, predicting strong correlations among different lepton flavors, with a few channels close to the experimental sensitivity

    Distribution of Relaxation Times Based on Lasso Regression: A Tool for High-Resolution Analysis of IMPS Data in Photoelectrochemical Systems

    Get PDF
    Intensity-modulated photocurrent spectroscopy (IMPS) has been largely employed in semiconductor characterization for solar energy conversion devices to probe the operando behavior with widely available facilities. However, the implementation of IMPS data analysis to complex structures, whether based on the physical rate constant model (RCM) or the assumption-free distribution of relaxation times (DRT), is generally limited to a semi-quantitative description of the charge carrier kinetics of the system. In this study, a new algorithm for the analysis of IMPS data is developed, providing unprecedented time resolution to the investigation of μs to s charge carrier dynamics in semiconductor-based systems used in photoelectrochemistry and photovoltaics. The algorithm, based on the previously developed DRT analysis, is herein modified with a Lasso regression method and available to the reader free of charge. A validation of this new algorithm is performed on a α-Fe2O3 photoanode for photoelectrochemical water splitting, identified as a standard platform in the field, highlighting multiple potential-dependent charge transfer paths, otherwise hidden in the conventional IMPS data analysis

    Business of Fashion, Textiles & Technology: Summary Report: Mapping the UK Fashion, Textiles and Technology Ecosystem

    Get PDF
    The UK fashion, apparel and textiles industry is a globally competitive growth sector. The 2015 Value of Fashion report by Oxford Economics, commissioned by the British Fashion Council, found that the direct economic value of a flourishing sector including retail, manufacturing and textiles was £28.1 billion – and calculated its indirect impact at a further £22.6 billion, making a total contribution to gross domestic product of over £50 billion[3]. However, it is less well understood than other creative industries. The final product is generally perceived as catwalk-related in some way. In order to shift that perception, the Business of Fashion, Textiles and Technology (BFTT) report considers the fashion, textiles and technology industry as a wide range of intersecting sectors, spanning – quite literally – from agriculture to advertising. To date, the industry has been constrained by lack of innovation in business strategy and the late adoption of technology. These structural factors have severely limited investment in research, development and knowledge exchange within the broader Fashion, Textiles and Technology (FTT) ecosystem. Currently, the industry lacks robust data and compelling evidence compared to other creative industries regarding research and development (R&D) opportunities, business growth options, job creation and investment. Official data sources on the fashion industry are limited to ‘designer fashion’, which is conflated with ‘other design’ activity, and focuses on established brands and large retailers, and unrelated textiles manufacturers. In response to this deficit and to concerns around R&D, identified through the development of the BFTT creative R&D partnership proposal (2017), the BFTT’s first task was to launch a UK-wide survey of the FTT ecosystem (2019). Approximately one year later, the survey consultation (the launch of which preceded Covid-19 and Britain’s exit from the EU) had engaged over 2,400 small, medium and micro businesses (SMEs) and over 100 stakeholders and intermediaries, including industry specialists, trade bodies and workspace providers. The consultation received 814 survey responses and led to 65 stakeholder interviews, making it one of the most extensive baseline studies to date on FTT SMEs. BFTT surveyed and interviewed across the entire UK fashion and wider apparel value chain. Therefore, this report for the first time positions the UK sector as not weighted toward fashion only. It illustrates the textile, materials and technology elements as key parts of this ecosystem and shows the industry is highly heterogeneous, made up of intersecting textiles and technology companies that inform an array of multiple sectors

    In vitro selection of resistance in Streptococcus pneumoniae at in vivo fluoroquinolone concentrations

    Get PDF
    Methods: Twenty strains of S. pneumoniae susceptible to fluoroquinolones were used. The frequencies of spontaneous single-step mutations at plasma and epithelial lining fluid (ELF) peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial subcultures on agar plates containing a linear gradient from peak to trough antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. Resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing gyrA, gyrB, parC and parE genes. Results: Levofloxacin and moxifloxacin showed the lowest frequencies of mutations (median <10 211 ) at plasma peak and at ELF concentrations, while medians ranging from 10 28 to 10 26 were observed for ciprofloxacin and prulifloxacin. In a multi-step selection assay, ciprofloxacin and prulifloxacin selected for the highest number of resistant strains (19 and 31, respectively). No selection of resistance was observed for levofloxacin at ELF concentrations and for moxifloxacin at plasma and ELF concentrations. Mutations in parC, parE and gyrA genes were found in ciprofloxacin- and prulifloxacinresistant strains, while only parC mutations were found for levofloxacin. Conclusions: Levofloxacin and moxifloxacin are characterized by a lower propensity to select in vitro for resistance in S. pneumoniae than ciprofloxacin and prulifloxacin, when tested at plasma and lung concentrations

    The Submillimeter Properties of the 1 Ms Chandra Deep Field North X-ray Sample

    Get PDF
    We present submillimeter observations for 136 of the 370 X-ray sources detected in the 1 Ms exposure of the Chandra Deep Field North. Ten of the X-ray sources are significantly detected in the submillimeter. The average X-ray source in the sample has a significant 850 micron flux of 1.69+/-0.27 mJy. This value shows little dependence on the 2-8 keV flux from 5e-16 erg/cm^2/s to 1e-14 erg/cm^2/s. The ensemble of X-ray sources contribute about 10% of the extragalactic background light at 850 microns. The submillimeter excess is found to be strongest in the optically faint X-ray sources that are also seen at 20 cm, which is consistent with these X-ray sources being obscured and at high redshift (z>1).Comment: 5 pages, submitted to The Astrophysical Journal Letter

    Biomass from microalgae: The potential of domestication towards sustainable biofactories

    Get PDF
    Interest in bulk biomass from microalgae, for the extraction of high-value nutraceuticals, bio-products, animal feed and as a source of renewable fuels, is high. Advantages of microalgal vs. plant biomass production include higher yield, use of non-arable land, recovery of nutrients from wastewater, efficient carbon capture and faster development of new domesticated strains. Moreover, adaptation to a wide range of environmental conditions evolved a great genetic diversity within this polyphyletic group, making microalgae a rich source of interesting and useful metabolites. Microalgae have the potential to satisfy many global demands; however, realization of this potential requires a decrease of the current production costs. Average productivity of the most common industrial strains is far lower than maximal theoretical estimations, suggesting that identification of factors limiting biomass yield and removing bottlenecks are pivotal in domestication strategies aimed to make algal-derived bio-products profitable on the industrial scale. In particular, the light-to-biomass conversion efficiency represents a major constraint to finally fill the gap between theoretical and industrial productivity. In this respect, recent results suggest that significant yield enhancement is feasible. Full realization of this potential requires further advances in cultivation techniques, together with genetic manipulation of both algal physiology and metabolic networks, to maximize the efficiency with which solar energy is converted into biomass and bio-products. In this review, we draft the molecular events of photosynthesis which regulate the conversion of light into biomass, and discuss how these can be targeted to enhance productivity through mutagenesis, strain selection or genetic engineering. We outline major successes reached, and promising strategies to achieving significant contributions to future microalgae-based biotechnology
    • …
    corecore