Predicting Intermediate Storage Performance for Workflow Applications

Configuring a storage system to better serve an application is a challenging task complicated by a multidimensional, discrete configuration space and the high cost of space exploration (e.g., by running the application with different storage configurations). To enable selecting the best configuration in a reasonable time, we design an end-to-end performance prediction mechanism that estimates the turn-around time of an application using storage system under a given configuration. This approach focuses on a generic object-based storage system design, supports exploring the impact of optimizations targeting workflow applications (e.g., various data placement schemes) in addition to other, more traditional, configuration knobs (e.g., stripe size or replication level), and models the system operation at data-chunk and control message level. This paper presents our experience to date with designing and using this prediction mechanism. We evaluate this mechanism using micro- as well as synthetic benchmarks mimicking real workflow applications, and a real application.. A preliminary evaluation shows that we are on a good track to meet our objectives: it can scale to model a workflow application run on an entire cluster while offering an over 200x speedup factor (normalized by resource) compared to running the actual application, and can achieve, in the limited number of scenarios we study, a prediction accuracy that enables identifying the best storage system configuration

Continuous Uniform Finite Time Stabilization of Planar Controllable Systems

Continuous homogeneous controllers are utilized in a full state feedback setting for the uniform finite time stabilization of a perturbed double integrator in the presence of uniformly decaying piecewise continuous disturbances. Semiglobal strong $\mathcal{C}^1$ Lyapunov functions are identified to establish uniform asymptotic stability of the closed-loop planar system. Uniform finite time stability is then proved by extending the homogeneity principle of discontinuous systems to the continuous case with uniformly decaying piecewise continuous nonhomogeneous disturbances. A finite upper bound on the settling time is also computed. The results extend the existing literature on homogeneity and finite time stability by both presenting uniform finite time stabilization and dealing with a broader class of nonhomogeneous disturbances for planar controllable systems while also proposing a new class of homogeneous continuous controllers

Isotopic Production Cross Sections in Proton-Nucleus Collisions at 200 MeV

Intermediate mass fragments (IMF) from the interaction of $^{27}$Al, $^{59}$Co and $^{197}$Au with 200 MeV protons were measured in an angular range from 20 degree to 120 degree in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double differential cross sections, energy differential cross sections and total cross sections were extracted.Comment: accepted by Phys. Rev.

Investigating the Magnetic Structure of Interplanetary Coronal Mass Ejections using Simultaneous Multi-Spacecraft In situ Measurements

In situ measurements from spacecraft typically provide a time series at a single location through coronal mass ejections (CMEs) and they have been one of the main methods to investigate CMEs. CME properties derived from these in situ measurements are affected by temporal changes that occur as the CME passes over the spacecraft, such as radial expansion and ageing, as well as spatial variations within a CME. This study uses multi-spacecraft measurements of the same CME at close separations to investigate both the spatial variability (how different a CME profile is when probed by two spacecraft close to each other) and the so-called ageing effect (the effect of the time evolution on in situ properties). We compile a database of 19 events from the past four decades measured by two spacecraft with a radial separation <0.2 au and an angular separation <10{\deg}. We find that the average magnetic field strength measured by the two spacecraft differs by 18% of the typical average value, which highlights non-negligible spatial or temporal variations. For one particular event, measurements taken by the two spacecraft allow us to quantify and significantly reduce the ageing effect to estimate the asymmetry of the magnetic field strength profile. This study reveals that single-spacecraft time series near 1 au can be strongly affected by ageing and that correcting for self-similar expansion does not capture the whole ageing effect.Comment: Accepted for publication at ApJ. 18 pages, 6 figures, 2 table

The Tunisian traditional rabbit breeding system versus the commercial system: an epidemiological perspective

[EN] Rabbit breeding is practiced in many hot climate countries and contributes in terms of agricultural activities to rural development. In Tunisia two different rabbit breeding systems can be identified - the "traditional" (an integrated free range and underground system) and the "commercial" (employing sheds and wire net cages) practice. 24 Tunisian rabbitries (10 traditional and 14 commercial) were included in an epidemiological study aimed at comparing the prevalence of pathogenic bacteria responsible for upper respiratory and digestive diseases in the two breeding systems. A total of 128 adult rabbits (mean age of 9.4 months) were tested using deep nasal and rectal swabs. Symptoms of nasal discharge and/or diarrhea were recorded. 281 bacterial strains were isolated in total, 138 in commercial and 143 in traditional farms. The bacteria most frequently isolated (61.2%) were Gram-positive strains, which included Streptococcus sp. (22.8%), coagulase negative Staphylococcus sp. (17.8%) and coagulase-positive Staphylococcus (17.4%) strains. Among the Gram-negative isolated bacteria, Escherichia coli was the most frequent (12.5%), followed by Proteus sp. (5.7%). The two Salmonella strains isolated were Salmonella bongori (found in the commercial system), and Salmonella typhimurium definitive phage-type (DT) 104 (found in the traditional farming system). The absence of Pasteurella multocida in the list of isolated bacteria may be directly correlated to the method of conserving the samples (storage at freezing temperature). The coagulase-positive Staphylococcus strains were frequently isolated (73.5%) from healthy rabbits, but seldom from rabbits with rhinitis (18.4%) or diarrhea (8.2%). Staphylococcus aureus strains were recovered at a higher rate in commercial farms (21%) in comparison with traditional (11.9%) farms. However, this difference was not statistically significant. Four Staphylococcus aureus strains, all belonging to commercial farms, proved positive when tested for enterotoxin production. The antimicrobial susceptibility of isolated Staphylococcus aureus strains was also investigated. Most of the antibiotics tested were very effective: the highest level of susceptibility was observed with enrofloxacin (100%). The low performance of Tunisian traditional rabbit rearing has been linked to the high mortality rate, which may possibly be due to the increased presence of pathogens at the rabbit flock level. However, this was not confirmed by the results of our study due to the fact that the bacterial contamination seems to be comparable in both the traditional and the commercial breeding systems.Belli, P.; Fontana, E.; Sommariva, M.; Scarpelli, L.; Ricci, C.; Luzi, F.; Haddad, B. (2008). The Tunisian traditional rabbit breeding system versus the commercial system: an epidemiological perspective. World Rabbit Science. 16(4). doi:10.4995/wrs.2008.617SWORD16

On the Absorption of X-rays in the Interstellar Medium

We present an improved model for the absorption of X-rays in the ISM intended for use with data from future X-ray missions with larger effective areas and increased energy resolution such as Chandra and XMM, in the energy range above 100eV. Compared to previous work, our formalism includes recent updates to the photoionization cross section and revised abundances of the interstellar medium, as well as a treatment of interstellar grains and the H2molecule. We review the theoretical and observational motivations behind these updates and provide a subroutine for the X-ray spectral analysis program XSPEC that incorporates our model.Comment: ApJ, in press, for associated software see http://astro.uni-tuebingen.de/nh

Implementação de diagnóstico por PCR para Fusarium oxysporum f. sp. cubense (raça 4).

O mal-do-panamá é um dos principais problemas fitossanitários da bananeira, causado pelo Fusarium oxysporum f. sp. cubense. A única alternativa eficiente para o controle da doença tem sido a utilização de variedades resistentes, o que nem sempre é possível. O surgimento de novas raças é preocupação constante

Isospin Diffusion in 58^{58}Ni-Induced Reactions at Intermediate Energies

Isospin diffusion is probed as a function of the dissipated energy by studying two systems $^{58}$Ni+$^{58}$Ni and $^{58}$Ni+$^{197}$Au, over the incident energy range 52-74\AM. Experimental data are compared with the results of a microscopic transport model with two different parameterizations of the symmetry energy term. A better overall agreement between data and simulations is obtained when using a symmetry term with a potential part linearly increasing with nuclear density. The isospin equilibration time at 52 \AM{} is estimated to 130$\pm$10 fm/$c$