Black hole entropy quantization

Ever since the pioneer works of Bekenstein and Hawking, black hole entropy has been known to have a quantum origin. Furthermore, it has long been argued by Bekenstein that entropy should be quantized in discrete (equidistant) steps given its identification with horizon area in (semi-)classical general relativity and the properties of area as an adiabatic invariant. This lead to the suggestion that black hole area should also be quantized in equidistant steps to account for the discrete black hole entropy. Here we shall show that loop quantum gravity, in which area is {\it not} quantized in equidistant steps can nevertheless be consistent with Bekenstein's equidistant entropy proposal in a subtle way. For that we perform a detailed analysis of the number of microstates compatible with a given area and show consistency with the Bekenstein framework when an oscillatory behavior in the entropy-area relation is properly interpreted.Comment: 4 pages, 4 figures. Version to be published in PR

Current State of Basic and Translational Cardiovascular Research in Spain

European Union's FP7 (CardioNext ITN-608027, HEALTH. 2011-278967), European Union's Horizon 2020 (GA633765, RIA73152, AC16/00021, and AC16/00091), the Spanish Ministerio de Economia, Industria y Competitividad (MEIC) with cofunding from the Fondo Europeo de Desarrollo Regional (FEDER; SAF2015-65722-R, SAF2016-79490-R, SAF2013-49663-EXP, RTC-2015-4398-1, and RTC-2016-4911-1), the Carlos III Institute of Health-Fondo de Investigacion Sanitaria (PI16/02110, PI16/00123, DTS17/00136, and DTS15/00095), Fundacion BBVA, Mutua Madrilena Foundation, Spanish Society of Cardiology, the Fundacio Marato TV3 (122/C/2015), and the Progeria Research Foundation (Established Investigator Award 2014-52). The CNIC is supported by the MEIC and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505).S

Combinatorics of the SU(2) black hole entropy in loop quantum gravity

We use the combinatorial and number-theoretical methods developed in previous works by the authors to study black hole entropy in the new proposal put forth by Engle, Noui, and Pérez. Specifically, we give the generating functions relevant for the computation of the entropy and use them to derive its asymptotic behavior, including the value of the Immirzi parameter and the coefficient of the logarithmic correction.The authors want to thank Alejandro Pérez for interesting discussions on this subject. The work was partially supported by the Spanish MICINN research grants FIS2008-01980, FIS2008-03221, FIS2008-06078-C03-02 and ESP2007-66542-C04-01, and the Consolider-Ingenio 2010 Program CPAN (CSD2007-00042). I.A. has been partially supported by RGI founds of the Center of Gravitation and Cosmology at the University of Wisconsin-Milwaukee

Virtual reality training platform for flexible ureterorenoscopy interventions with a minimally invasive surgical robot

The total number of ureteroscopy (URS) interventions during the past years has dramatically increased due to the ongoing technological advances and the benefits associated with these techniques. However, the current URS procedure presents some drawbacks to urologic surgeons. The LITHOS project was created with the main objective of developing a surgical robotic system for flexible ureterorenoscopic lithotripsy interventions, offering a technological solution that meets the real needs of both patients and surgeons in this type of procedures. In this paper, a virtual reality environment for flexible ureterorenoscopy interventions is presented. The proposed environment provides a suitable training platform for surgeons manipulating the surgical robotic system

Entorno didáctico de bajo coste para formación en tecnologías de cirugía guiada por imagen y robótica

Este trabajo de investigación presenta un nuevo entorno didáctico de bajo coste para la formación ingenieril de temáticas de cirugía guiada por imagen y robótica. Con este entorno se pretende mejorar la motivación y autonomía del alumnado, que hasta el momento se hallaba acotada debido al alto componente teórico de las sesiones impartidas. El entorno está formado por un phantom, una herramienta software, un sistema robótico y un manipulador que permite obtener una realimentación háptica. Se ha llevado a cabo una experiencia piloto en la asignatura de cuarto curso "Simulación y planificación quirúrgica" del Grado de Ingeniería Biomédica de la Universidad Politécnica de Madrid. Los resultados de las encuestas llevadas a cabo muestran que la nueva metodología mejora en todos los casos los valores obtenidos usando la metodología clásica basada en la clase magistral y prácticas

Loop quantum gravity and Planck-size black hole entropy

The Loop Quantum Gravity (LQG) program is briefly reviewed and one of its main applications, namely the counting of black hole entropy within the framework is considered. In particular, recent results for Planck size black holes are reviewed. These results are consistent with an asymptotic linear relation (that fixes uniquely a free parameter of the theory) and a logarithmic correction with a coefficient equal to -1/2. The account is tailored as an introduction to the subject for non-experts.Comment: 21 pages, 5 figures. Contribution to the Proceedings of the NEB XII International Conferenc

Black hole state degeneracy in Loop Quantum Gravity

The combinatorial problem of counting the black hole quantum states within the Isolated Horizon framework in Loop Quantum Gravity is analyzed. A qualitative understanding of the origin of the band structure shown by the degeneracy spectrum, which is responsible for the black hole entropy quantization, is reached. Even when motivated by simple considerations, this picture allows to obtain analytical expressions for the most relevant quantities associated to this effect.Comment: 22 pages, 7 figure

Ex-situ genetic conservation of Pinus nigra salzmannii endangered populations from the Spanish Central Range: abstract

Publishe

Human colon-derived soluble factors modulate gut microbiota composition

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).-- et al.The commensal microbiota modulates immunological and metabolic aspects of the intestinal mucosa contributing to development of human gut diseases including inflammatory bowel disease. The host/microbiota interaction often referred to as a crosstalk, mainly focuses on the effect of the microbiota on the host neglecting effects that the host could elicit on the commensals. Colonic microenvironments from three human healthy controls (obtained from the proximal and distal colon, both in resting conditions and after immune - IL-15-and microbiota - LPS-in vitro challenges) were used to condition a stable fecal population. Subsequent 16S rRNA gene-based analyses were performed to study the effect induced by the host on the microbiota composition and function. Non-supervised principal component analysis (PCA) showed that all microbiotas, which had been conditioned with colonic microenvironments clustered together in terms of relative microbial composition, suggesting that soluble factors were modulating a stable fecal population independently from the treatment or the origin. Our findings confirmed that the host intestinal microenvironment has the capacity to modulate the gut microbiota composition via yet unidentified soluble factors. These findings indicate that an appropriate understanding of the factors of the host mucosal microenvironment affecting microbiota composition and function could improve therapeutic manipulation of the microbiota composition.BS and AH were recipients of a Ramón y Cajal postdoctoral contract and a FPI grant, respectively, from the Spanish Ministry of Economy and Competitiveness. The authors gratefully acknowledge the support of the Biotechnology and Biological Sciences Research Council (BBSRC). This research was funded by the BBSRC Institute Strategic Programme for Gut Health and Food Safety BB/J004529/1. This research was also funded by Grants AGL2010-14952 and AGL2013-44039-R from the Spanish “Plan Estatal de I + D + i,” and by Grant EM2014/046 from the “Plan galego de investigación, innovación e crecemento 2011-2015.”Peer Reviewe

A model for evaluation of generic competences in engineering: application to the problem. Solving competence at the technical University of Madrid.

The competence evaluation promoted by the European High Education Area entails a very important methodological change that requires guiding support to help teachers carry out this new and complex task. In this regard, the Technical University of Madrid (UPM, by its Spanish acronym) has financed a series of coordinated projects with a two-fold objective: a) To develop a model for teaching and evaluating core competences that is useful and easily applicable to its different degrees, and b) to provide support to teachers by creating an area within the Website for Educational Innovation where they can search for information on the model corresponding to each core competence approved by UPM. Information available on each competence includes its definition, the formulation of indicators providing evidence on the level of acquisition, the recommended teaching and evaluation methodology, examples of evaluation rules for the different levels of competence acquisition, and descriptions of best practices. These best practices correspond to pilot tests applied to several of the academic subjects conducted at UPM in order to validate the model. This work describes the general procedure that was used and presents the model developed specifically for the problem-solving competence. Some of the pilot experiences are also summarised and their results analyse