When is a parasite not a parasite? Effects of larval tick burdens on white-footed mouse survival

Many animal species can carry considerable burdens of ectoparasites: parasites living on the outside of a host's body. Ectoparasite infestation can decrease host survival, but the magnitude and even direction of survival effects can vary depending on the type of ectoparasite and the nature and duration of the association. When ectoparasites also serve as vectors of pathogens, the effects of ectoparasite infestation on host survival have the potential to alter disease dynamics by regulating host populations and stabilizing transmission. We quantified the impact of larval Ixodes scapularis tick burdens on both within-season and overwinter survival of white-footed mice (Peromyscus leucopus) using a hierarchical Bayesian capture-mark-recapture model. I. scapularis and P. leucopus are, respectively, vectors and competent reservoirs for the causative agents of Lyme disease, anaplasmosis, and babesiosis. Using a data set of 5587 individual mouse capture histories over sixteen years, we found little evidence for any effect of tick burdens on either within-season or overwinter mouse survival probabilities. In male mice, tick burdens were positively correlated with within-season survival probabilities. Mean maximum tick burdens were also positively correlated with population rates of change during the concurrent breeding season. The apparent indifference of mice to high tick burdens may contribute to their effectiveness as reservoir hosts for several human zoonotic pathogens.Fil: Hersh, Michelle H.. Cary Institute of Ecosystem Studies; Estados Unidos. Bard College. Program in Biology; Estados Unidos. Sarah Lawrence College; Estados UnidosFil: LaDeau, Shannon L.. Cary Institute of Ecosystem Studies; Estados UnidosFil: Previtali, Maria Andrea. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Ostfeld, Richard S.. Cary Institute of Ecosystem Studies; Estados Unido

Scintillating double beta decay bolometers

We present the results obtained in the development of scintillating Double Beta Decay bolometers. Several Mo and Cd based crystals were tested with the bolometric technique. The scintillation light was measured through a second independent bolometer. A 140 g CdWO_4 crystal was run in a 417 h live time measurement. Thanks to the scintillation light, the alpha background is easily discriminated resulting in zero counts above the 2615 keV gamma line of Thallium 208. These results, combined with an extremely easy light detector operation, represent the first tangible proof demonstrating the feasibility of this kind of technique.Comment: 15 pages, 8 figure

Size scaling of the addition spectra in silicon quantum dots

We investigate small artificial quantum dots obtained by geometrically controlled resistive confinement in low mobility silicon-on-insulator nanowires. Addition spectra were recorded at low temperature for various dot areas fixed by lithography. We compare the standard deviation of the addition spectra with theory in the high electron concentration regime. We find that the standard deviation scales as the inverse area of the dot and its absolute value is comparable to the energy spacing of the one particle spectrum.Comment: 4 pages, 5 figure

Analysis of a possible application of a new process for oxygen enriched air production

A new process for oxygen enriched air (EA) production has been applied to Claus Process. This process is simple and requires few process units. Matlab and Aspen Hysys have been used for simulations and system sizing. The results demonstrate that it could be an alternative to traditional EA processes from an economical point of view

Critical Current Density in Superconducting Nb-Ti Strands in the 100 mT to 11 T Applied Field Range

The knowledge of the critical current density in a wide temperature and applied magnetic field range is a crucial issue for the design of a superconducting magnet, especially for determining both current and temperature margins. The critical current density of LHC-type Nb-Ti strands of 0.82 and 0.48 mm diameter was measured by means of critical current and magnetization measurements at both 4.2 K and 1.9 K and for a broad magnetic field range (up to 11 T). For the magnetic field range common to both measurement methods, critical current density values as extracted from transport current and from magnetization data are compared and found fairly consistent. Our experimental data are compared to other sets from literature and to scaling laws as well

Laser surface structuring of AZ31 Mg alloy for controlled wettability

Structured surfaces exhibit functional properties that can enhance the performance of a bioimplant in terms of biocompatibility, adhesion, or corrosion behavior. In order to tailor the surface property, chemical and physical methods can be used in a sequence of many steps. On the other hand, laser surface processing can provide a single step solution to achieve the designated surface function with the use of simpler equipment and high repeatability. This work provides the details on the surface structuring of AZ31, a biocompatible and biodegradable Mg alloy, by a single-step laser surface structuring based on remelting. The surfaces are characterized in terms of topography, chemistry, and physical integrity, as well as the effective change in the surface wetting behavior is demonstrated. The results imply a great potential in local or complete surface structuring of medical implants for functionalization by the flexible positioning of the laser beam

Critical Current Studies on Deformed Nb-Ti Strands

The Nb-Ti hard conductors used in LHC dipole and quadrupole magnets are Rutherford cables composed of several tens of strands. During the cabling process, the strands are severely compacted especially at the thin edge of the cable. In order to assess, on the whole wire length, the deformation effect on the transport current of the wires, LHC-type Nb-Ti superconducting strands of various types were flattened by means of rollers. The critical current was then measured as a function of deformation and applied magnetic field at both 4.3 K and 1.9 K. The measurements were performed for both orientations (flat face perpendicular or parallel to magnetic field). The critical current density anisotropy of such deformed strands and the correlation with magnetization effects are discussed. This study permits to better understand and to quantify the critical current degradation of few percent observed in strands due to cabling. Comparisons with wires extracted from Rutherford cables are presented

Measurements of the effect of collisions on transverse beam halo diffusion in the Tevatron and in the LHC

Beam-beam forces and collision optics can strongly affect beam lifetime, dynamic aperture, and halo formation in particle colliders. Extensive analytical and numerical simulations are carried out in the design and operational stage of a machine to quantify these effects, but experimental data is scarce. The technique of small-step collimator scans was applied to the Fermilab Tevatron collider and to the CERN Large Hadron Collider to study the effect of collisions on transverse beam halo dynamics. We describe the technique and present a summary of the first results on the dependence of the halo diffusion coefficient on betatron amplitude in the Tevatron and in the LHC.Comment: 4 pages, 2 figures. Submitted to the Proceedings of the ICFA Mini-Workshop on Beam-beam Effects in Hadron Colliders (BB2013), Geneva, Switzerland, 18-22 March 201