Two-photon double ionization of neon using an intense attosecond pulse train

We present the first demonstration of two-photon double ionization of neon using an intense extreme ultraviolet (XUV) attosecond pulse train (APT) in a photon energy regime where both direct and sequential mechanisms are allowed. For an APT generated through high-order harmonic generation (HHG) in argon we achieve a total pulse energy close to 1 $\mu$J, a central energy of 35 eV and a total bandwidth of $\sim30$ eV. The APT is focused by broadband optics in a neon gas target to an intensity of $3\cdot10^{12}$W$\cdot$cm$^{-2}$. By tuning the photon energy across the threshold for the sequential process the double ionization signal can be turned on and off, indicating that the two-photon double ionization predominantly occurs through a sequential process. The demonstrated performance opens up possibilities for future XUV-XUV pump-probe experiments with attosecond temporal resolution in a photon energy range where it is possible to unravel the dynamics behind direct vs. sequential double ionization and the associated electron correlation effects

Diagnóstico situacional Hospital Gaspar García Laviana- Rivas y Ernesto Sequeira- Región Autónoma Atlántico Sur. Nicaragua. Año 2004.

Estudio de tipo descriptivo de corte transversal, en los Hospitales Ernesto Sequeira de la Región Autónoma del Atlántico Sur y Gaspar García Laviana de Rivas durante el año 2004. Se encontró que en ambos Hospitales brindan atención general, de prioridad Materno-Infantil, ubicados en las cabeceras de los departamentos; pertenecen al Segundo nivel de atención, con un nivel de complejidad básico, de referencias departamental para los centros de salud, cuyo propietario es el Ministerio de Salud. Con poblaciones objetivos mayores de 175,000 habitantes donde el 65% de las personas son niños o mujeres en edad de procrear. La cartera de servicios que ofertan ambos hospitales es acorde a su complejidad en las que se encuentran las cuatro especialidades básicas Medicina Interna, Cirugía General, Pediatría y Gineco obstetricia y los servicios de apoyo tales como: Farmacia, Radiología, Laboratorio así como en su estructura física cuenta con consultorios para consulta externa, emergencia, quirófanos, salas de parto y camas censables. El número de recursos humanos en cada hospital es mayor a 300 personas, donde el 55 al 60% es asistencial. En los recursos financieros el 80% del presupuesto proviene de fondo fiscal y el mayor gasto es en el pago de recursos humanos. El equipamiento asistencial de los hospitales se encuentra desfasado y obsoleto, entre el 20 al 40% en regular y muy mal estado y tienen más de un año de estar sin funcionamiento y no han sido reparados. El modelo de gestión de ambos hospitales es tradicional, sin implementación de herramientas gerenciales, ni toma de decisiones. La producción de servicios es baja en relación a su capacidad instalada

Production/maintenance cooperative scheduling using multi-agents and fuzzy logic

Within companies, production is directly concerned with the manufacturing schedule, but other services like sales, maintenance, purchasing or workforce management should also have an influence on this schedule. These services often have together a hierarchical relationship, i.e. the leading function (most of the time sales or production) generates constraints defining the framework within which the other functions have to satisfy their own objectives. We show how the multi-agent paradigm, often used in scheduling for its ability to distribute decision-making, can also provide a framework for making several functions cooperate in the schedule performance. Production and maintenance have been chosen as an example: having common resources (the machines), their activities are actually often conflicting. We show how to use a fuzzy logic in order to model the temporal degrees of freedom of the two functions, and show that this approach may allow one to obtain a schedule that provides a better compromise between the satisfaction of the respective objectives of the two functions

Can Thermoclines Be a Cue to Prey Distribution for Marine Top Predators? A Case Study with Little Penguins

The use of top predators as bio-platforms is a modern approach to understanding how physical changes in the environment may influence their foraging success. This study examined if the presence of thermoclines could be a reliable signal of resource availability for a marine top predator, the little penguin (Eudyptula minor). We studied weekly foraging activity of 43 breeding individual penguins equipped with accelerometers. These loggers also recorded water temperature, which we used to detect changes in thermal characteristics of their foraging zone over 5 weeks during the penguin’s guard phase. Data showed the thermocline was detected in the first 3 weeks of the study, which coincided with higher foraging efficiency. When a thermocline was not detected in the last two weeks, foraging efficiency decreased as well. We suggest that thermoclines can represent temporary markers of enhanced food availability for this top-predator to which they must optimally adjust their breeding cycle

Windscapes shape seabird instantaneous energy costs but adult behavior buffers impact on offspring

Acknowledgements K. Ashbrook, M. Barrueto, K. Elner, A. Hargreaves, S. Jacobs, G. Lancton, M. LeVaillant, E. Grosbellet, A. Moody, A. Ronston, J. Provencher, P. Smith, K. Woo and P. Woodward helped in the field. J. Nakoolak kept us safe from bears. N. Sapir and two anonymous reviewers provided very useful comments on an earlier version of our manuscript. R. Armstrong at the Nunavut Research Institute, M. Mallory at the Canadian Wildlife Service Northern Research Division and C. Eberl at National Wildlife Research Centre in Ottawa provided logistical support. F. Crenner, N. Chatelain and M. Brucker customized the GPS at the IPHC-CNRS. KHE received financial support through a NSERC Vanier Canada Graduate Scholarship, ACUNS Garfield Weston Northern Studies scholarship and AINA Jennifer Robinson Scholarship and JFH received NSERC Discovery Grant funding. J. Welcker generously loaned some accelerometers. All procedures were approved under the guidelines of the Canadian Council for Animal Care.Peer reviewedPublisher PD