5,515 research outputs found

    Lectures on mathematical aspects of (twisted) supersymmetric gauge theories

    Full text link
    Supersymmetric gauge theories have played a central role in applications of quantum field theory to mathematics. Topologically twisted supersymmetric gauge theories often admit a rigorous mathematical description: for example, the Donaldson invariants of a 4-manifold can be interpreted as the correlation functions of a topologically twisted N=2 gauge theory. The aim of these lectures is to describe a mathematical formulation of partially-twisted supersymmetric gauge theories (in perturbation theory). These partially twisted theories are intermediate in complexity between the physical theory and the topologically twisted theories. Moreover, we will sketch how the operators of such a theory form a two complex dimensional analog of a vertex algebra. Finally, we will consider a deformation of the N=1 theory and discuss its relation to the Yangian, as explained in arXiv:1308.0370 and arXiv:1303.2632.Comment: Notes from a lecture series by the first author at the Les Houches Winter School on Mathematical Physics in 2012. To appear in the proceedings of this conference. Related to papers arXiv:1308.0370, arXiv:1303.2632, and arXiv:1111.423

    Point-of-care ultrasonography—An essential skill for medical graduates?

    Full text link
    The recent proliferation of point-of-care ultrasonography (POCUS) in the clinical practice of many medical specialties has exposed persistent barriers to education, training and standardisation. Specialist training curriculums are already overwhelming, having grossly insufficient time available for the specialist trainees and for the small number of available trainers alike to incorporate POCUS into postgraduate education. The logical solution to overcome these barriers could be to incorporate basic POCUS education and training into the undergraduate university curriculums, introducing longitudinal integration with other relevant medical sciences. The Australasian Society of Ultrasound in Medicine already has well-established educational programmes in POCUS with standardised assessment of competency, which could potentially offer the basis for symbiosis with the Australian and New Zealand medical schools

    Equivalences between GIT quotients of Landau-Ginzburg B-models

    Full text link
    We define the category of B-branes in a (not necessarily affine) Landau-Ginzburg B-model, incorporating the notion of R-charge. Our definition is a direct generalization of the category of perfect complexes. We then consider pairs of Landau-Ginzburg B-models that arise as different GIT quotients of a vector space by a one-dimensional torus, and show that for each such pair the two categories of B-branes are quasi-equivalent. In fact we produce a whole set of quasi-equivalences indexed by the integers, and show that the resulting auto-equivalences are all spherical twists.Comment: v3: Added two references. Final version, to appear in Comm. Math. Phy

    Analysis of the Thermodynamic Phase Transition of Tracked Convective Clouds Based on Geostationary Satellite Observations

    Get PDF
    Clouds are liquid at temperature greater than 0°C and ice at temperature below −38°C. Between these two thresholds, the temperature of the cloud thermodynamic phase transition from liquid to ice is difficult to predict and the theory and numerical models do not agree: Microphysical, dynamical, and meteorological parameters influence the glaciation temperature. We temporally track optical and microphysical properties of 796 clouds over Europe from 2004 to 2015 with the space‐based instrument Spinning Enhanced Visible and Infrared Imager on board the geostationary METEOSAT second generation satellites. We define the glaciation temperature as the mean between the cloud top temperature of those consecutive images for which a thermodynamic phase change in at least one pixel is observed for a given cloud object. We find that, on average, isolated convective clouds over Europe freeze at −21.6°C. Furthermore, we analyze the temporal evolution of a set of cloud properties and we retrieve glaciation temperatures binned by meteorological and microphysical regimes: For example, the glaciation temperature increases up to 11°C when cloud droplets are large, in line with previous studies. Moreover, the correlations between the parameters characterizing the glaciation temperature are compared and analyzed and a statistical study based on principal component analysis shows that after the cloud top height, the cloud droplet size is the most important parameter to determine the glaciation temperature

    Coating selection program - Theory

    Get PDF
    Heat balance equations for optimizing optical coating patterns for spacecraft temperature control syste

    Absolute photoionization cross section measurements of the Kr I-isoelectronic sequence

    Get PDF
    Photoionization spectra have been recorded in the 4s, 4p and 3d resonance regions for the Kr Iisoelectronic sequence using both the dual laser produced plasma technique (at DCU) to produce photoabsorption spectra, and the merged ion beam and synchrotron radiation technique (at ASTRID) to measure absolute photoionization cross sections. Profile parameters are compared for the 4s − np resonances of Rb+ and Sr2+. Many new 4p " ns, md transitions are identified with the aid of Hartree-Fock calculations, and consistent quantum defects are observed for the various ns and md Rydberg series. Absolute single and double photoionization cross sections recorded in the 3d region for Rb+ and Sr2+ ions show preferential decay via double photoionization. This is only the second report where both the DLP technique and the merged beam technique have been used simultaneously to record photoionization spectra, and the advantages of both techniques (i.e. better resolution in the case of DLP and values for absolute photoionization cross sections in the case of the merged beam technique) are highlighted

    Evolving localizations in reaction-diffusion cellular automata

    Full text link
    We consider hexagonal cellular automata with immediate cell neighbourhood and three cell-states. Every cell calculates its next state depending on the integral representation of states in its neighbourhood, i.e. how many neighbours are in each one state. We employ evolutionary algorithms to breed local transition functions that support mobile localizations (gliders), and characterize sets of the functions selected in terms of quasi-chemical systems. Analysis of the set of functions evolved allows to speculate that mobile localizations are likely to emerge in the quasi-chemical systems with limited diffusion of one reagent, a small number of molecules is required for amplification of travelling localizations, and reactions leading to stationary localizations involve relatively equal amount of quasi-chemical species. Techniques developed can be applied in cascading signals in nature-inspired spatially extended computing devices, and phenomenological studies and classification of non-linear discrete systems.Comment: Accepted for publication in Int. J. Modern Physics

    Reef Rescue Marine Monitoring Program: Report of AIMS Activities: inshore coral reef monitoring 2012. Report for Great Barrier Reef Marine Park Authority

    Get PDF
    The coral reef monitoring component of the Reef Rescue Marine Monitoring Program (MMP) undertaken in 2012 was a continuation of activities under previous arrangements from 2005 to 2011. The coral monitoring program surveyed the cover of benthic organisms, the numbers of coral genera, the number of juvenile-sized coral colonies and sediment quality at inshore reef locations in four Natural Resource Management (NRM) regions: Wet Tropics; Burdekin; Mackay Whitsunday; and Fitzroy. Monitoring of coral recruitment also continued at three core reef sites in each of the four Regions. The completion of the eighth inshore coral reef survey under the MMP allows for updated assessments of the overall condition of inshore coral reef communities

    Community interventions to reduce child mortality in Dhanusha, Nepal: study protocol for a cluster randomized controlled trial

    Get PDF
    Background: Neonatal mortality remains high in rural Nepal. Previous work suggests that local women's groups can effect significant improvement through community mobilisation. The possibility of identification and management of newborn infections by community-based workers has also arisen.Methods/Design: The objective of this trial is to evaluate the effects on newborn health of two community-based interventions involving Female Community Health Volunteers.MIRA Dhanusha community groups: a participatory intervention with women's groups. MIRA Dhanusha sepsis management: training of community volunteers in the recognition and management of neonatal sepsis. The study design is a cluster randomized controlled trial involving 60 village development committee clusters allocated 1:1 to two interventions in a factorial design.MIRA Dhanusha community groups: Female Community Health Volunteers (FCHVs) are supported in convening monthly women's groups. Nine groups per cluster (270 in total) work through two action research cycles in which they (i) identify local issues around maternity, newborn health and nutrition, (ii) prioritise key problems, (iii) develop strategies to address them, (iv) implement the strategies, and (v) evaluate their success. Cycle 1 focuses on maternal and newborn health and cycle 2 on nutrition in pregnancy and infancy and associated postpartum care practices. MIRA Dhanusha sepsis management: FCHVs are trained to care for vulnerable newborn infants. They (i) identify local births, (ii) identify low birth weight infants, (iii) identify possible newborn infection, (iv) manage the process of treatment with oral antibiotics and referral to a health facility to receive parenteral gentamicin, and (v) follow up infants and support families.Primary outcome: neonatal mortality rates. Secondary outcomes: MIRA Dhanusha community group: stillbirth, infant and under-two mortality rates, care practices and health care seeking behaviour, maternal diet, breastfeeding and complementary feeding practices, maternal and under-2 anthropometric status. MIRA Dhanusha sepsis management: identification and treatment of neonatal sepsis by community health volunteers, infection-specific neonatal mortality
    • 

    corecore