396 research outputs found

    \pi N scattering in relativistic baryon chiral perturbation theory revisited

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    We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of Infrared Regularization up to {\cal O}(q^3) in the chiral expansion, where q is a generic small momentum. We describe the low-energy phase shifts with a similar quality as previously achieved with Heavy Baryon Chiral Perturbation Theory, \sqrt{s}\lesssim1.14 GeV. New values are provided for the {\cal O}(q^2) and {\cal O}(q^3) low-energy constants, which are compared with previous determinations. This is also the case for the scattering lengths and volumes. Finally, we have unitarized the previous amplitudes and as a result the energy range where data are reproduced increases significantly.Comment: 26 pages, 5 figures, 5 table

    Some cultural consequences in Spain of the Spanish Invasion of Morocco 1859-60

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    This article argues is a contribution to the study of interrelationships between colonialism, art, and literature in the nineteenth century. The article argues that the Spanish invasion of Morocco in 1859 led to contradictions and tensions within liberal nationalism, not least because of concerns about the tensions between the need for military reassertion of Spain and the respect for the independence of nations. This led to some reconfiguration of Spanish intellectuals' already complex relationship with North Africa and Islam. A major, perhaps surprising consequence of this reconfiguration, was some equation of Moroccan identity with a monotonous surface that was resistant to the gaze. In consequence, the Catalan painter Fortuny's crucial experience of Morocco led him to value near blank surfaces, and thus to make a major contribution to the origins of modern art

    Analog gravity from field theory normal modes?

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    We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the large number of ``analog models'' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is something more fundamental going on. Indeed, linearization of a classical field theory (a field theoretic ``normal mode analysis'') results in fluctuations whose propagation is governed by a Lorentzian-signature curved spacetime ``effective metric''. For a single scalar field, this procedure results in a unique effective metric, which is quite sufficient for simulating kinematic aspects of general relativity (up to and including Hawking radiation). Quantizing the linearized fluctuations, the one-loop effective action contains a term proportional to the Einstein--Hilbert action, suggesting that while classical physics is responsible for generating an ``effective geometry'', quantum physics can be argued to induce an ``effective dynamics''. The situation is strongly reminiscent of Sakharov's ``induced gravity'' scenario, and suggests that Einstein gravity is an emergent low-energy long-distance phenomenon that is insensitive to the details of the high-energy short-distance physics. (We mean this in the same sense that hydrodynamics is a long-distance emergent phenomenon, many of whose predictions are insensitive to the short-distance cutoff implicit in molecular dynamics.)Comment: Revtex 4 (beta 5); 12 pages in single-column forma

    Population of Merging Compact Binaries Inferred Using Gravitational Waves through GWTC-3

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    We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star–black hole mergers. We infer the binary neutron star merger rate to be between 10 and 1700  Gpc−3 yr−1 and the neutron star–black hole merger rate to be between 7.8 and 140  Gpc−3 yr−1, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods used in this work. We infer the binary black hole merger rate, allowing for evolution with redshift, to be between 17.9 and 44  Gpc−3 yr−1 at a fiducial redshift (z=0.2). The rate of binary black hole mergers is observed to increase with redshift at a rate proportional to (1+z)κ with κ=2.9+1.7−1.8 for z≲1. Using both binary neutron star and neutron star–black hole binaries, we obtain a broad, relatively flat neutron star mass distribution extending from 1.2+0.1−0.2 to 2.0+0.3−0.3M⊙. We confidently determine that the merger rate as a function of mass sharply declines after the expected maximum neutron star mass, but cannot yet confirm or rule out the existence of a lower mass gap between neutron stars and black holes. We also find the binary black hole mass distribution has localized over- and underdensities relative to a power-law distribution, with peaks emerging at chirp masses of 8.3+0.3−0.5 and 27.9+1.9−1.8M⊙. While we continue to find that the mass distribution of a binary’s more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above approximately 60M⊙, which would indicate the presence of a upper mass gap. Observed black hole spins are small, with half of spin magnitudes below χi≈0.25. While the majority of spins are preferentially aligned with the orbital angular momentum, we infer evidence of antialigned spins among the binary population. We observe an increase in spin magnitude for systems with more unequal-mass ratio. We also observe evidence of misalignment of spins relative to the orbital angular momentum

    (Un)becoming women: Indian factory women's counternarratives of gender

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    This paper portrays the life stories of five factory workers in Delhi whose life trajectories run counter to normative femininity. As daughters and wives, they are neglected, abandoned or rejected by their families; they live alone, with their parents past the age that is their natal right, with siblings, or with families and men who are not related to them. I explore the circulation of their counternarratives and how their gender transgressions go public through ordinary forms of talk, such as gossip and rumor. I argue that their move out of the normative is not produced by, but produces, their gender politics; that their agency emerges cognitively from the telling of their stories in tandem with their interlocutors' credulity and uptake; and that the site of gender politics for working class Indian women lies in the informal subaltern publics that are formed by the circulation of their stories. Contrary to the notion of a stable unitary subject that precedes the political, these women's counternarratives demonstrate the subject‐in‐process as a political effect. Their alterity does not exist outside the heteronormative gender order but demarcates the boundaries of its historicity, hinting at both the internal contradictions of existing gender relations and their future possibilities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112196/1/j.1467-954X.2011.02026.x.pd

    Uso de compuestos nutracéuticos en nuevas formulaciones de piensos acuícolas

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    Trabajo presentado en las X Jornadas de Acuicultura en el Litoral Suratlántico: Nuevos retos y perspectivas para la sostenibilidad de la acuicultura, celebrado entre el 22 y 23 de noviembre de 2023 en Huelva.[EN] Different strategies have been followed to improve the aquaculture of main European farmed fish, such as genetic selection, refinements in culture conditions or enhanced feed formulation and management. However, more knowledge is required to exploit fish phenotypic plasticity to obtain those that better match aquaculture or market conditions. The overall objective of this mini-review is to identify the latest productive traits recently performed, mainly in commercial carnivorous species, and underlying biological processes that would be susceptible to improve the competitivity of aquaculture sector through nutritional issues. Thus, this work is framed within the concepts of Circular Economy and Blue Growth, where it is intended to point out the use of natural compounds extracted from seaweeds, microalgae and by-products of the industry for their inclusion in aquafeeds, allowing a more efficient use of more sustainable vegetable protein sources, and also to evaluate if these nutraceutical compounds counteract detrimental effects observed by nutritional interventions or environmentally challenged.[ES] La producción acuícola ha seguido diferentes estrategias para su optimización a lo largo de las últimas décadas, como el desarrollo de la selección genética, la mejora de las condiciones de cultivo, o el avance en la formulación y gestión de los piensos. Sin embargo, se requiere más conocimiento para explotar la plasticidad fenotípica de los peces para obtener aquellos que se ajusten mejor a las condiciones de la acuicultura o del mercado. El objetivo general de esta mini-revisión es identificar los últimos avances realizados recientemente, principalmente en especies carnívoras comerciales, y los procesos biológicos subyacentes que serían susceptibles de mejorar la competitividad del sector acuícola a través de intervenciones nutricionales. Así, este trabajo se enmarca dentro de los conceptos de Economía Circular y Crecimiento Azul, donde se pretende señalar el uso de compuestos naturales extraídos de algas, microalgas y subproductos de la industria para su inclusión en alimentos acuícolas, permitiendo un uso más eficiente de fuentes de proteínas vegetales más sostenibles, y también evaluar si estos compuestos nutracéuticos son capaces de contrarrestar los efectos perjudiciales observados por las formulaciones inadecuadas o desafiados por factores ambientales estresantes.This work was supported by the Projects “FEDER-UCA18-107182”, “FisioBream-II Call for Young Researchers CEI⋅MAR 2019”, “ALGAE4FISH-CEI·MAR Empresa 2018”, “VALINVA-CEI·MAR Empresa 2019”, “SeriBlue-CEI·MAR Empresa 2020”, and co-financed by the spin-off LifeBioencapsulation S.L. (Almería) and Biotechnology Biopolym S.A. (Granada)

    Exploring Health Science Students’ Notions on Organ Donation and Transplantation: A Multicenter Study

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    The knowledge acquired during university education about organ donation and transplantation (ODT) decisively influences the information future health professionals transmit. This is important in ODT where the participation of the general public is essential to obtain organs. Objective: To determine notions of Spanish medicine and nursing students on ODT and its relationship with attitude toward ODT. Methods and Design: and design. We conducted a sociologic, multicenter, and observational study. The population for our study consisted of medical and nursing students in Spanish universities. Our database was the Collaborative International Donor Project, stratified by geographic area and academic course. A validated questionnaire (PCID-DTO-RIOS) was self-administered and completed anonymously. Our sample consisted of 9598 medical and 10, 566 nursing students (99% confidence interval; precision of ±1%), stratified by geographic area and year of study. Results: The completion rate for our study was 90%. Only 20% (n=3640) of students thought their notions on ODT were good; 41% (n=7531) thought their notions were normal; 36% (n=6550) thought their notions were scarce. Comparing groups, there were differences between those who believed that their notions on ODT were good (44% nursing vs 56% medical students; P < .000), and those who believed it scarce (54% nursing vs 46% medical students; P < .000). Notions on ODT were related with attitude toward the donation of one''s own organs: those who considered their notions were good were more in favor then those who considered it scarce (88% vs 72%; P < .000). Conclusion: Only 20% of Spanish medical and nursing students thought their notions on ODT were good. Having good knowledge is related to a favorable attitude towards ODT. Receiving specific information on the subject could improve their knowledge about ODT during their training

    Profile and professional expectations of medical students from 11 Latin American countries: the Red-LIRHUS project

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    Background Latin America is undergoing a human resource crisis in health care in terms of labor shortage, misdistribution and poor orientation to primary care. Workforce data are needed to inform the planning of long-term strategies to address this problem. This study aimed to evaluate the academic and motivational profile, as well as the professional expectations, of Latin American medical students. Results We conducted an observational, cross-sectional, multi-country study evaluating medical students from 11 Spanish-speaking countries in 2011–2012. Motivations to study medicine, migration intentions, intent to enter postgraduate programs, and perceptions regarding primary care were evaluated via a self-administered questionnaire. Outcomes were measured with pilot-tested questions and previously validated scales. A total of 11,072 valid surveys from 63 medical schools were gathered and analyzed. Conclusions This study describes the profile and expectations of the future workforce being trained in Latin America. The obtained information will be useful for governments and universities in planning strategies to improve their current state of affairs regarding human resources for health care professions

    Prognostic factors in left-sided endocarditis: results from the andalusian multicenter cohort

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    <p>Abstract</p> <p>Background</p> <p>Despite medical advances, mortality in infective endocarditis (IE) is still very high. Previous studies on prognosis in IE have observed conflicting results. The aim of this study was to identify predictors of in-hospital mortality in a large multicenter cohort of left-sided IE.</p> <p>Methods</p> <p>An observational multicenter study was conducted from January 1984 to December 2006 in seven hospitals in Andalusia, Spain. Seven hundred and five left-side IE patients were included. The main outcome measure was in-hospital mortality. Several prognostic factors were analysed by univariate tests and then by multilogistic regression model.</p> <p>Results</p> <p>The overall mortality was 29.5% (25.5% from 1984 to 1995 and 31.9% from 1996 to 2006; Odds Ratio 1.25; 95% Confidence Interval: 0.97-1.60; p = 0.07). In univariate analysis, age, comorbidity, especially chronic liver disease, prosthetic valve, virulent microorganism such as <it>Staphylococcus aureus</it>, <it>Streptococcus agalactiae </it>and fungi, and complications (septic shock, severe heart failure, renal insufficiency, neurologic manifestations and perivalvular extension) were related with higher mortality. Independent factors for mortality in multivariate analysis were: Charlson comorbidity score (OR: 1.2; 95% CI: 1.1-1.3), prosthetic endocarditis (OR: 1.9; CI: 1.2-3.1), <it>Staphylococcus aureus </it>aetiology (OR: 2.1; CI: 1.3-3.5), severe heart failure (OR: 5.4; CI: 3.3-8.8), neurologic manifestations (OR: 1.9; CI: 1.2-2.9), septic shock (OR: 4.2; CI: 2.3-7.7), perivalvular extension (OR: 2.4; CI: 1.3-4.5) and acute renal failure (OR: 1.69; CI: 1.0-2.6). Conversely, <it>Streptococcus viridans </it>group etiology (OR: 0.4; CI: 0.2-0.7) and surgical treatment (OR: 0.5; CI: 0.3-0.8) were protective factors.</p> <p>Conclusions</p> <p>Several characteristics of left-sided endocarditis enable selection of a patient group at higher risk of mortality. This group may benefit from more specialised attention in referral centers and should help to identify those patients who might benefit from more aggressive diagnostic and/or therapeutic procedures.</p
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