75 research outputs found

    N=2 Supersymmetric Kinks and real algebraic curves

    Get PDF
    The kinks of the (1+1)-dimensional Wess-Zumino model with polynomic superpotential are investigated and shown to be related to real algebraic curves.Comment: 8 pages, LaTeX, epsfig, 4 figures include

    Factorization of supersymmetric Hamiltonians in curvilinear coordinates

    Get PDF
    Planar supersymmetric quantum mechanical systems with separable spectral problem in curvilinear coordinates are analyzed in full generality. We explicitly construct the supersymmetric extension of the Euler/Pauli Hamiltonian describing the motion of a light particle in the field of two heavy fixed Coulombian centers. We shall also show how the SUSY Kepler/Coulomb problem arises in two different limits of this problem: either, the two centers collapse in one center - a problem separable in polar coordinates -, or, one of the two centers flies to infinity - to meet the Coulomb problem separable in parabolic coordinates.Comment: 13 pages. Based on the talk presented by M.A. Gonzalez Leon at the 7th International Conference on Quantum Theory and Symmetries (QTS7), August 07-13, 2011, Prague, Czech Republi

    Diversity of introduced terrestrial flatworms in the Iberian Peninsula: a cautionary tale

    Get PDF
    Many tropical terrestrial planarians (Platyhelminthes, Geoplanidae) have been introduced around the globe. One of these species is known to cause significant decline in earthworm populations, resulting in a reduction of ecological functions that earthworms provide. Flatworms, additionally, are a potential risk to other species that have the same dietary needs. Hence, the planarian invasion might cause significant economic losses in agriculture and damage to the ecosystem. In the Iberian Peninsula only Bipalium kewenseMoseley, 1878 had been cited till 2007. Fromthat year on, four more species have been cited, and several reports of the presence of these animals in particular gardens have been received. In the present study we have: (1) analyzed the animals sent by non-specialists and also the presence of terrestrial planarians in plant nurseries and garden centers; (2) identified their species through morphological and phylogenetic molecular analyses, including representatives of their areas of origin; (3) revised their dietary sources and (4) used Species DistributionModeling (SDM) for one species to evaluate the risk of its introduction to natural areas. The results have shown the presence of at least ten species of alien terrestrial planarians, fromall its phylogenetic range. International plant trade is the source of these animals, and many garden centers are acting as reservoirs. Also, landscape restoration to reintroduce autochthonous plants has facilitated their introduction close to natural forests and agricultural fields. In conclusion, there is a need to take measures on plant trade and to have special care in the treatment of restored habitat

    New scalar field models and their defect solutions

    Get PDF
    Preprint[EN] In this work we introduce new scalar field models and study the defect solutions they may engender. The investigation is based on the deformation procedure, which greatly simplify the calculations, leading us to new models together with the corresponding solutions in a simple and powerful manner. [ES] En este trabajo presentamos nuevos modelos de campo escalar y estudiar los defectos las soluciones que pueden generar. La investigación se basa en el procedimiento de deformación, que simplifican en gran medida los cálculos, nos conduce a nuevos modelos junto con las soluciones correspondientes de una manera sencilla y de gran alcance

    Generalized Zeta Functions and One-loop Corrections to Quantum Kink Masses

    Get PDF
    A method for describing the quantum kink states in the semi-classical limit of several (1+1)-dimensional field theoretical models is developed. We use the generalized zeta function regularization method to compute the one-loop quantum correction to the masses of the kink in the sine-Gordon and cubic sinh-Gordon models and another two P(ϕ)2{\rm P}(\phi)_2 systems with polynomial self-interactions.Comment: 29 pages, 4 figures; version to appear in Nucl. Phys.

    Deformed defects for scalar fields with polynomial interactions

    Get PDF
    In this paper we use the deformation procedure introduced in former work on deformed defects to investigate several new models for real scalar field. We introduce an interesting deformation function, from which we obtain two distinct families of models, labeled by the parameters that identify the deformation function. We investigate these models, which identify a broad class of polynomial interactions. We find exact solutions describing global defects, and we study the corresponding stability very carefully.Comment: 8 pages, 5 eps figures, to appear in PR

    Hand motor fatigability induced by a simple isometric task in spinal cord injury

    Get PDF
    [Abstract] This study aimed: (1) to evaluate the hand motor fatigability in people with spinal cord injury (SCI) and compare it with measurements obtained form an able-bodied population; (2) to compare the hand motor fatigability in people with tetraplegia and in people with paraplegia; and (3) to analyse if motor fatigability is different in people with SCI with and without clinical significant perceived fatigability. Materials and methods: 96 participants with SCI (40 cervical and 56 thoracolumbar) and 63 able-bodied controls performed a simple hand isometric task to assess motor fatigability. The Fatigue Severity Scale was used for perceived fatigability evaluation. Results: The main results of this study can be summarized as follows: (1) the waning in muscle force (motor fatigability) during a fatiguing task is similar in controls and participants with SCI; (2) the motor fatigability is influenced by the maximal muscle force (measured at the beginning of the task); and (3) the perceived fatigability and the motor fatigability are largely independent in the individuals with SCI. Conclusion: Our findings suggest that the capability to maintain a prolonged effort is preserved in SCI, and this capacity depends on the residual maximal muscle force in people with SCI.Instituto de Salud Carlos III; ICI20/0007

    Physicochemical Quality, Antioxidant Capacity and Nutritional Value in Tuberous Roots of Some Wild Dahlia Species

    Get PDF
    The aim of this research was to evaluate the physicochemical quality, antioxidant capacity and nutritional value in tuberous roots of some wild dahlia species. The experiment was carried out in the Department of Plant Science of the Autonomous University Chapingo, Mexico. Plants were established in a randomized complete block design with five replications. The total soluble solids (TSS), titratable acidity (TA), vitamin C (VC), total phenols (TP), antioxidant capacity (AC), inulin and its proximate composition were evaluated. Among the materials analyzed, the most outstanding wild species were Dahlia campanulata, D. coccinea and D. brevis, where D. campanulata stood out for its concentration of VC (0.05 mg 100 g-1), AC (1.88 mg VCEAC g-1), inulin, DM and TC (72.25, 24.38 and 88.37%, respectively), however, the inulin content was similar to D. coccinea (66.17%), which was also outstanding with respect to the content of TP (1.74 mg GA g-1). Likewise, D. brevis presented the highest values of RFi (5.49%) and A (78.42%). According to our results, the tuberous roots of wild dahlia species can be used as food, as well as being a source of selection of traits of nutraceutic interest for genetic improvement

    The burden of hospital malnutrition in Spain: methods and development of the PREDyCES® study

    Get PDF
    It is well known that hospital malnutrition is a highly prevalent condition associated to increase morbidity and mortality as well as related healthcare costs. Although previous studies have already measured the prevalence and/or costs of hospital nutrition in our country, their local focus (at regional or even hospital level) make that the true prevalence and economic impact of hospital malnutrition for the National Health System remain unknown in Spain. The PREDyCES® (Prevalence of hospital malnutrition and associated costs in Spain) study was aimed to assess the prevalence of hospital malnutrition in Spain and to estimate related costs. Some aspects made this study unique: a) It was the first study in a representative sample of hospitals of Spain; b) different measures to assess hospital malnutrition (NRS2002, MNA as well as anthropometric and biochemical markers) where used both at admission and discharge and, c) the economic consequences of malnutrition where estimated using the perspective of the Spanish National Health System.Es bien sabido que la desnutrición hospitalaria es un proceso altamente prevalente asociado al aumento de la morbilidad y mortalidad, así como a elevados costes sanitarios. Aunque estudios previos han medido la prevalencia y/o los costes de la nutrición hospitalaria en nuestro país, su enfoque local (regional o incluso a nivel hospitalario) hacen que la verdadera prevalencia e impacto económico de la desnutrición hospitalaria para el Sistema Nacional de Salud sean aún desconocidos en España. El objetivo del estudio PREDyCES® (Prevalencia de la Desnutrición hospitalaria y los Costes asociados en ESpaña) fue evaluar la prevalencia de la desnutrición hospitalaria en España y estimar sus costes asociados. Algunos aspectos de este estudio lo hicieron singular: a) Fue el primer estudio de este tipo con una muestra representativa de los hospitales de España, b) se utilizaron diferente medidas para evaluar la desnutrición hospitalaria (NRS 2002, MNA, así como marcadores antropométricos y bioquímicos) tanto en el momento del ingreso como al alta hospitalaria y, c) se estimaron las consecuencias económicas de la desnutrición desde la perspectiva del Sistema Nacional de Salud español
    corecore