3,253 research outputs found

    Superconducting properties of the attractive Hubbard model

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    A self-consistent set of equations for the one-electron self-energy in the ladder approximation is derived for the attractive Hubbard model in the superconducting state. The equations provide an extension of a T-matrix formalism recently used to study the effect of electron correlations on normal-state properties. An approximation to the set of equations is solved numerically in the intermediate coupling regime, and the one-particle spectral functions are found to have four peaks. This feature is traced back to a peak in the self-energy, which is related to the formation of real-space bound states. For comparison we extend the moment approach to the superconducting state and discuss the crossover from the weak (BCS) to the intermediate coupling regime from the perspective of single-particle spectral densities.Comment: RevTeX format, 8 figures. Accepted for publication in Z.Phys.

    Sobre la biología del águila calzada Hieraëtus pennatus (Gmelin, 1788) en Navarra

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    Trata el presente trabajo de aspectos de la Biología del Águila calzada (Hieraétus pennatus) durante el período reproductor según observaciones realizadas en unos parajes de la zona media de Navarra. Comienza con la descripción del sistema de trabajo y posteriormente, se describe la especie, su habitat, distribución geográfica y estatus en Navarra. Según fechas de observación de los autores se trata de la fenología de migración. Un capítulo más extenso describe el comportamiento territorial y nupcial de la especie y se dan todos los datos básicos relativos a fechas de puesta de huevos, nacimiento de los pollos, período de dependencia con sus padres etc. Se citan observaciones originales relativas a la agresividad entre los pollos en varias especies de rapaces. Se dan datos sobre alimentación de las especies y el trabajo acaba describiendo los cambios de los individuos que compusieron una pareja de águilas calzadas que nidificó en el mismo bosque durante 17 años, pudiéndose estudiar, por ello, la productividad de tal pareja en dicho período de tiempo

    Comparison and Uniqueness Results for the Periodic Boundary Value Problem for Linear First-Order Differential Equations Subject to a Functional Perturbation

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    This is a post-peer-review, pre-copyedit version of a chapter published in Area I. et al. (eds) Nonlinear Analysis and Boundary Value Problems. NABVP 2018. Springer Proceedings in Mathematics & Statistics, vol 292. Springer, Cham. The final authenticated version is available online at: https://doi.org/10.1007/978-3-030-26987-6_14We improve some comparison results for the periodic boundary value problem related to a first-order differential equation perturbed by a functional term. The comparison results presented cover many cases as differential equations with delay, differential equations with maxima and integro-differential equations. The interesting case of functional perturbation with piecewise constant arguments is also analyzed

    Microbial catabolic activities are naturally selected by metabolic energy harvest rate

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    The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate

    PCV33 COST-EFFECTIVENESS MODEL TO EVALUATE MANAGED VENTRICULAR PACING (MVP) IMPLANTED IN A SPANISH AMBULATORY SURGERY PROGRAM

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    Exploring the natural history of intrinsic capacity impairments: longitudinal patterns in the 10/66 study

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    Backgroundintrinsic capacity (IC) is a construct encompassing people’s physical and mental abilities. There is an implicit link amongst IC domains: cognition, locomotion, nutrition, sensory and psychological. However, little is known about the integration of the domains.Objectivesto investigate patterns in the presentation and evolution of IC domain impairments in low-and-middle-income countries and if such patterns were associated with adverse outcomes.Methodssecondary analyses of the first two waves of the 10/66 study (population-based surveys conducted in eight urban and four rural catchment areas in Cuba, Dominican Republic, Puerto Rico, Venezuela, Peru, Mexico and China). We applied latent transition analysis on IC to find latent statuses (latent clusters) of IC domain impairments. We evaluated the longitudinal association of the latent statuses with the risk of frailty, disability and mortality, and tested concurrent and predictive validity.Resultsamongst 14,923 participants included, the four latent statuses were: high IC (43%), low deterioration with impaired locomotion (17%), high deterioration without cognitive impairment (22%), and high deterioration with cognitive impairment (18%). A total of 61% of the participants worsened over time, 35% were stable, and 3% improved to a healthier status.Participants with deteriorated IC had a significantly higher risk of frailty, disability and dementia than people with high IC. There was strong concurrent and predictive validity. (Mortality Hazard Ratio = 4.60, 95%CI 4.16; 5.09; Harrel’s C = 0.73 (95%CI 0.72;0.74)).Conclusionshalf of the study population had high IC at baseline, and most participants followed a worsening trend. Four qualitatively different IC statuses or statuses were characterised by low and high levels of deterioration associated with their risk of disability and frailty. Locomotion and cognition impairments showed other trends than psychological and nutrition domains across the latent statuses

    Study of Beauveria bassiana growth, blastospore yield, desiccation-tolerance, viability and toxic activity using different liquid media

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    Beauveria bassiana was grown on three liquid media containing casaminoacids, corn steep liquor or peptone. After incubation, the blastospore counts reached 6.38 × 109 blastospores/ml, in the medium containing sucrose and corn steep liquor, which was significantly higher than the obtained with media containing casaminoacids or peptone. The medium containing corn steep liquor produced predominately submerged conidia, meanwhile the other media produced blastospores. The blastospores produced in the medium containing casaminoacids presented faster germination rates, than the blastospores produced in media containing corn steep liquor or peptone, although, after airdrying, were observed significant reductions on the viability of blastospores produced in the media composed by casaminoacids or peptone, but the spores produced in the medium with corn steep liquor were not affected. For storage of blastospores at 4 and 26°C after some months, the blastospores produced in the medium with casaminoacids showed the highest viability at 26°C, whereas at 4°C the counts of viable blastospores produced in medium containing corn steep liquor were significantly higher than the counts of blastospores produced in the other media with casaminoacids or peptone. The blastospores maintained for six months at 4°C showed high mortality against third-instar Plutella xylostella larvae.Key words: Beauveria bassiana, liquid media, fermentation, short times of propagation, biological control, entomopathogen fungus

    Perampanel outcomes at different stages of treatment in people with focal and generalized epilepsy treated in clinical practice: Evidence from the PERMIT study

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    IntroductionThe PERMIT study is the largest pooled analysis of perampanel (PER) clinical practice data conducted to date.MethodsThis post-hoc analysis of PERMIT investigated the effectiveness, safety and tolerability of PER when used as early add-on therapy (after failure of one or two previous antiseizure medications) in comparison with late add-on therapy (after failure of three or more previous antiseizure medications). Retention and effectiveness were assessed after 3, 6, and 12 months, and at the last visit (last observation carried forward). Effectiveness was assessed by seizure type (total seizures, focal seizures, generalized tonic-clonic seizures [GTCS]) and assessments included seizure freedom rate and responder rate. Safety and tolerability were assessed by evaluating adverse events (AEs) and discontinuation due to AEs.ResultsThe Full Analysis Set included 1184 and 2861 PWE treated with PER as early and late add-on therapy, respectively. Compared to the late add-on subgroup, the early add-on subgroup was characterized by later mean age at epilepsy onset, shorter mean duration of epilepsy, lower rates of intellectual disability and psychiatric comorbidity, and lower frequency of seizures per month, suggesting a less severe form of epilepsy in this subgroup. After 12 months, retention was significantly higher in the early versus late add-on subgroup (67.7% vs. 62.4%; p = 0.004). At the last visit, responder rates in the early versus late add-on subgroup were significantly higher for total seizures (68.2% vs. 39.3%; p &amp;lt; 0.001), focal seizures (65.0% vs. 36.8%; p &amp;lt; 0.001) and GTCS (83.7% vs. 67.2%; p &amp;lt; 0.001), as were seizure freedom rates (total seizures, 35.9% vs. 11.9% [p &amp;lt; 0.001]; focal seizures, 29.4% vs. 8.7% [p &amp;lt; 0.001]; GTCS, 69.0% vs. 48.1% [p &amp;lt; 0.001]). Incidence of AEs was significantly lower in the early versus late add-on subgroup (42.1% vs. 54.7%; p &amp;lt; 0.001), as was the rate of discontinuation due to AEs over 12 months (15.0% vs. 18.1%; p = 0.031).DiscussionThis study demonstrated that PER was effective and generally well tolerated when initiated as early or late add-on therapy, but it was significantly more effective and better tolerated when initiated early. These findings support PER's use as a broad-spectrum, early add-on therapy for use in PWE with focal and generalized seizures.</jats:sec
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