Holographic zero sound at finite temperature in the Sakai-Sugimoto model

In this paper, we study the fate of the holographic zero sound mode at finite temperature and non-zero baryon density in the deconfined phase of the Sakai-Sugimoto model of holographic QCD. We establish the existence of such a mode for a wide range of temperatures and investigate the dispersion relation, quasi-normal modes, and spectral functions of the collective excitations in four different regimes, namely, the collisionless quantum, collisionless thermal, and two distinct hydrodynamic regimes. For sufficiently high temperatures, the zero sound completely disappears, and the low energy physics is dominated by an emergent diffusive mode. We compare our findings to Landau-Fermi liquid theory and to other holographic models.Comment: 1+24 pages, 19 figures, PDFTeX, v2: some comments and references added, v3: some clarifications relating to the different regimes added, matches version accepted for publication in JHEP, v4: corrected typo in eq. (3.18

Planning search and rescue missions for UAV teams

The coordination of multiple Unmanned Aerial Vehicles (UAVs) to carry out aerial surveys is a major challenge for emergency responders. In particular, UAVs have to fly over kilometre-scale areas while trying to discover casualties as quickly as possible. To aid in this process, it is desirable to exploit the increasing availability of data about a disaster from sources such as crowd reports, satellite re- mote sensing, or manned reconnaissance. In particular, such inform- ation can be a valuable resource to drive the planning of UAV flight paths over a space in order to discover people who are in danger. However challenges of computational tractability remain when plan- ning over the very large action spaces that result. To overcome these, we introduce the survivor discovery problem and present as our solu- tion, the first example of a continuous factored coordinated Monte Carlo tree search algorithm. Our evaluation against state of the art benchmarks show that our algorithm, Co-CMCTS, is able to localise more casualties faster than standard approaches by 7% or more on simulations with real-world data

Laboratorios virtuales de la licenciatura de ingeniería en sistemas computacionales de la Facultad de Ingeniería

Durante los últimos 20 años las tecnologías de la información (TIC‘s) han tenido una gran influencia en el proceso de enseñanza-aprendizaje en todos los niveles de educación en nuestro país. La influencia de estas proporciona en la actualidad nuevos esquemas y herramientas que abren un abanico de posibilidades, tanto para los docentes como para los alumnos. Este proyecto hace uso de una plataforma que permitirá la creación de máquinas virtuales para la mejor comprensión y realización de actividades en distintas asignaturas de la licenciatura de Ingeniería en Sistemas Computacionales; sin embargo, esta herramienta puede ser explotada en cualquier disciplina y con esto fomentar el uso de nuevos entornos de aprendizaje en los alumnos. En este proyecto utilizaremos Vmware ESXi 6.0.0 para la creación de la plataforma virtual y el VMware vSphere 5.0 para la conexión de los clientes a las máquina virtuales. El eje central del proyecto estará basado en el uso y gestión de las máquinas virtuales; los cuales permiten desarrollar nuevos escenarios de formación de conocimientos y así contribuir en la formación de las competencias de los alumnos. Con lo anterior, se lleva a cabo la formación de competencias, en cuyo estándar (modelo flexible basado en competencias), se basa la Universidad Autónoma de Campeche desde el 2009. Con este proyecto se pretende difundir el uso de las nuevas tecnologías, de las máquinas virtuales y proporcionar espacios flexibles para el desarrollo académico en la comunidad de nuestra facultad

Modulated Instability in Five-Dimensional U(1) Charged AdS Black Hole with R**2-term

We study the effect of R**2 term to the modulated instability in the U(1) charged black hole in five-dimensional Anti-de Sitter space-time. We consider the first-order corrections of R**2 term to the background and the linear order perturbations in the equations of motion. From the analysis, we clarify the effect of R**2 term in the modulated instability, and conclude that fluctuations are stable in the whole bulk in the range of values the coefficient of R**2 term can take.Comment: 19 pages, 1 figures; (v4) Published version in JHE

Childcare, choice and social class: Caring for young children in the UK

This paper draws on the results of two qualitative research projects examining parental engagements with the childcare market in the UK. Both projects are located in the same two London localities. One project focuses on professional middle class parents, and the other on working class families, and we discuss the key importance of social class in shaping parents' differential engagement with the childcare market, and their understandings of the role childcare plays in their children's lives. We identify and discuss the different "circuits" of care (Ball et al 1995) available to and used by families living physically close to each other, but in social class terms living in different worlds. We also consider parents' relationships with carers, and their social networks. We conclude that in order to fully understand childcare policies and practices and families' experiences of care, an analysis which encompasses social class and the workings of the childcare market is needed

Objetivos de aprendizaje en videos de la facultad de ingeniería, Universidad Autónoma de Campeche.

Las Tecnologías de Información y Comunicación (TIC‘s) forman parte de la vida de la mayoría de las personas. Hoy en día, el uso de estas tecnologías en los ambientes educativos está siendo demandado debido al impacto. Debido a lo anterior, se han desarrollado diversas plataformas que promueven el aprendizaje en redes y que funcionan como repositorios de contenido académico con el aval de prestigiosas universidades que son accesibles en línea fomentando la vinculación y el intercambio de conocimiento. Una de las herramientas más usadas en las plataformas son los Objetos de Aprendizaje(OA) que por su naturaleza basada en la programación orientada a objetos resultan una estrategia efectiva para lograr objetivos educativos, presentando información independiente que contribuye a un objetivo con mayor jerarquía agrupándose o reutilizándose en diversos contextos. Sin embargo, se suele encontrar OA que carecen de una estructura pedagógica, debido a que los docentes no emplean una metodología que los oriente en el proceso. El reto de muchos profesores es plasmar su conocimiento en plataformas que faciliten la distribución, sean atractivas y confiables; así contribuir a la red de conocimiento y al mismo tiempo fortalecer los materiales didácticos de sus programas educativos. El presente trabajo genera una metodología que guía al docente en la creación de objetos de aprendizajes en video de calidad accesibles en línea. Se propone una metodología de desarrollo que basada el trabajo colaborativo donde interviene un docente experto en contenido, un diseñador instruccional y un desarrollador tecnológico

Striped instability of a holographic Fermi-like liquid

We consider a holographic description of a system of strongly-coupled fermions in 2+1 dimensions based on a D7-brane probe in the background of D3-branes. The black hole embedding represents a Fermi-like liquid. We study the excitations of the Fermi liquid system. Above a critical density which depends on the temperature, the system becomes unstable towards an inhomogeneous modulated phase which is similar to a charge density and spin wave state. The essence of this instability can be effectively described by a Maxwell-axion theory with a background electric field. We also consider the fate of zero sound at non-zero temperature.Comment: 16 pages, 9 figures; v2: added discussion and one figure. Typos correcte

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age