Running-phase state in a Josephson washboard potential

We investigate the dynamics of the phase variable of an ideal underdamped Josephson junction in switching current experiments. These experiments have provided the first evidence for macroscopic quantum tunneling in large Josephson junctions and are currently used for state read-out of superconducting qubits. We calculate the shape of the resulting macroscopic wavepacket and find that the propagation of the wavepacket long enough after a switching event leads to an average voltage increasing linearly with time.Comment: 6 pages, 3 figure

A phenomenological analysis of azimuthal asymmetries in unpolarized semi-inclusive deep inelastic scattering

We present a phenomenological analysis of the cos-phi and cos-2phi asymmetries in unpolarized semi-inclusive deep inelastic scattering, based on the recent multidimensional data released by the COMPASS and HERMES Collaborations. In the TMD framework, valid at relatively low transverse momenta, these asymmetries arise from intrinsic transverse momentum and transverse spin effects, and from their correlations. The role of the Cahn and Boer-Mulders effects in both azimuthal moments is explored up to order 1/Q. As the kinematics of the present experiments is dominated by the low-Q^2 region, higher-twist contributions turn out to be important, affecting the results of our fits.Comment: 18 pages, 5 figures, one paragraph added at the end of Section IV, one reference added. PRD versio

Wild ruminants as reservoirs of domestic livestock gastrointestinal T nematodes

Gastrointestinal nematode (GIN) infections in cattle cause appetite suppression which leads to poor feed conversion, reduced weight gain and reduced milk production. Overuse and exclusive reliance on anthelmintic drugs has resulted in widespread resistance in many parasitic nematode species infecting livestock making control increasingly difficult. Wild ruminants are competent hosts of a number of nematode species that typically infect and are best adapted for cattle, sheep, and goats. Thus, the potential exists for wild ruminants to act as reservoirs in the translocation of domestic GIN, including those carrying anthelmintic resistance mutations as well as susceptible genotypes. The potential for parasite exchange is heightened by interfaces or ecotones between managed and wild rangelands, and by perturbations linked to climate warming that can increasingly alter the distributions of wild ungulates and their interactions with domestic and free-ranging ruminants. To investigate the extent to which wild ruminants harbour parasites capable of infecting domestic ruminants we first performed an epidemiological study of feces from wildlife hosts that spanned 16 states and included white-tailed deer (85 % of the samples), pronghorn, elk, mule deer, bighorn sheep, moose, cattle, and caribou across the United States. All samples were cultured to third stage larvae and nematode DNA was isolated and PCR amplified. Among the 548 wild ruminant samples received, 33 % (181 samples) were positive for nematode DNA, among which half (84 samples) contained DNA from GIN species commonly found in cattle. DNA from cattle GIN species was detected in 46 % of samples from the Northeast, 42 % from the Southeast, 10 % from the Midwest, 0 % from the Southwest and 11 % from the West. Deep amplicon sequencing of the ITS-2 rDNA indicated that Ostertagia and Trichostrongylus were present in 90 % and 69 % of the nematode DNA positive samples, respectively, whereas Haemonchus, Cooperia and Oesophagostomum were present in 26 %, 2 % and 10 % of the samples, respectively. These data clearly show that wild ruminants commonly harbour multiple parasite species whose primary hosts are domestic cattle, and suggest that further work is warranted to investigate their specific roles in the management of anthelmintic resistance

Determination Of Diffusion And Adsorption Coefficients For Some Contaminants In Clayey Soil And Rock: Laboratory Determination And Field Evaluation

A laboratory diffusion test determination of diffusion coefficient (D) and adsorption coefficient (K{dollar}\sb{lcub}\rm d{rcub}{dollar}) for various inorganic and organic species in a saturated, undisturbed, clayey soil is presented. Diffusion tests conducted for inorganic species (Cl{dollar}\sp-{dollar}, Na{dollar}\sp+{dollar}, K{dollar}\sp+{dollar}, Mg{dollar}\sp{lcub}2+{rcub}{dollar}, and Ca{dollar}\sp{lcub}2+{rcub}{dollar}), involved placing domestic landfill leachate on top of a layer of clay and allowing the chemical constituents to diffuse into the soil. The mathematical model POLLUTE was then used to back-figure (D) and (K{dollar}\sb{lcub}\rm d{rcub}{dollar}) for each species by fitting: (1) the variation in species concentration with time in the source leachate, and (2) the variation in pore water concentration with depth in the soil layer at the end of the test. Similar tests using a single salt dissolved in distilled water as the source solution, indicated that both D and K{dollar}\sb{lcub}\rm d{rcub}{dollar} of a given species are significantly influenced by the types and amounts of co-diffusing species present in the initial source solution.;Diffusion tests conducted for organic species (acetone, 1,4-dioxane, aniline, chloroform, and toluene), involved diffusion of the species from a source solution placed on one side of a clay plug, into a distilled water collector solution on the opposite side. Using POLLUTE, D and K{dollar}\sb{lcub}\rm d{rcub}{dollar} were then determined by fitting the measured concentration variation with time in both the source and collector solution. The test gave good results for the more soluble species: acetone, 1,4-dioxane, and aniline. The more hydrophobic species (chloroform and toluene), however, gave high D and K{dollar}\sb{lcub}\rm d{rcub}{dollar} values, partly due to adsorption of the species onto the walls of the diffusion cell.;In addition to the laboratory study, an investigation of inorganic contaminant diffusion below an existing industrial landfill site was conducted by analyzing soil and pore water specimens from the clay layer underlying the waste. Concentration profiles for Cl{dollar}\sp-{dollar}, So{dollar}\sb4\sp{lcub}2-{rcub}{dollar}, Na{dollar}\sp+{dollar}, Ca{dollar}\sp{lcub}2+{rcub}{dollar} and Mg{dollar}\sp{lcub}2+{rcub}{dollar}, showed above background levels to a depth of 1.4 m below the waste after 11 years of migration. K{dollar}\sp+{dollar}, B, and NH{dollar}\sb3{dollar}-N profiles, penetrated to less than 0.5 m below the waste. Field profiles for Na{dollar}\sp+{dollar}, K{dollar}\sp+{dollar}, Cl{dollar}\sp-{dollar}, and SO{dollar}\sb4\sp{lcub}2-{rcub}{dollar} were then compared with those predicted using POLLUTE with D and K{dollar}\sb{lcub}\rm d{rcub}{dollar} values obtained from diffusion tests using leachate and natural uncontaminated clay from the site. By assuming simple boundary conditions such as a constant source concentration, calculated profiles overestimated the upper part of the measured concentration profile, but reasonably predicted the depth of penetration.;Finally, a laboratory diffusion test determination of Cl{dollar}\sp-{dollar} diffusion coefficient in samples of intact, saturated shale and mudstone is presented. These tests were performed by placing distilled water in contact with core samples having a high initial Cl{dollar}\sp-{dollar} concentration. Chloride was then permitted to diffuse out of the sample and into the distilled water. At the end of the test the sample was sectioned, and the Cl{dollar}\sp-{dollar} profile measured. Provided that there is no significant moisture uptake from the distilled water reservoir, the diffusion profile developed could be adequately fitted using POLLUTE, and the diffusion coefficient determined

Low-temperature transport through a quantum dot between two superconductor leads

We consider a quantum dot coupled to two BCS superconductors with same gap energies $\Delta$. The transport properties are investigated by means of infinite-$U$ noncrossing approximation. In equilibrium density of states, Kondo effect shows up as two sharp peaks around the gap bounds. Application of a finite voltage bias leads these peaks to split, leaving suppressed peaks near the edges of energy gap of each lead. The clearest signatures of the Kondo effect in transport are three peaks in the nonlinear differential conductance: one around zero bias, another two at biases $\pm 2\Delta$. This result is consistent with recent experiment. We also predict that with decreasing temperature, the differential conductances at biases $\pm 2\Delta$ anomalously increase, while the linear conductance descends.Comment: replaced with revised versio

Transverse-momentum distributions in a diquark spectator model

All the leading-twist parton distribution functions are calculated in a spectator model of the nucleon, using scalar and axial-vector diquarks. Single gluon rescattering is used to generate T-odd distribution functions. Different choices for the diquark polarization states are considered, as well as a few options for the form factor at the nucleon-quark-diquark vertex. The results are listed in analytic form and interpreted in terms of light-cone wave functions. The model parameters are fixed by reproducing the phenomenological parametrization of unpolarized and helicity parton distributions at the lowest available scale. Predictions for the other parton densities are given and, whenever possible, compared with available phenomenological parametrizations.Comment: 42 pages, 13 figures in .eps format. RevTeX style. Minor typos corrected, added one referenc

To Accompany and to Observe: Engaged Scholarship and Social Change Vis-à-Vis Sub-Saharan Transmigration in Morocco

In this interview with Sabina Barone, Mehdi Alioua—Sociology Professor at the Université Internationale de Rabat (International University of Rabat), Morocco—reflects on the transformations that Sub-Saharan African migration has brought to Moroccan society over the last two decades, in particular with reference to identity and the denominations of the foreign others, the internal and regional dynamics of (im)mobility, and the challenges to social coexistence and national migration policies. He proposes conceptual categories such as “transmigrant,” “migration by stages,” and “migratory crossroads” to capture the complexity of the mobile experiences unfolding in Morocco. Based on his trajectory of engaged scholarship in favor of migrants and refugees, he calls for a renewed South-South and North-South academic collaboration and cross-fertilization through small scale, bottom-up research made possible by friendship among scholars

Dispersionless motion in a driven periodic potential

Recently, dispersionless (coherent) motion of (noninteracting) massive Brownian particles, at intermediate time scales, was reported in a sinusoidal potential with a constant tilt. The coherent motion persists for a finite length of time before the motion becomes diffusive. We show that such coherent motion can be obtained repeatedly by applying an external zero-mean square-wave drive of appropriate period and amplitude, instead of a constant tilt. Thus, the cumulative duration of coherent motion of particles is prolonged. Moreover, by taking an appropriate combination of periods of the external field, one can postpone the beginning of the coherent motion and can even have coherent motion at a lower value of position dispersion than in the constant tilt case.Comment: 4 pages, 4 figure

Developmental Exposure of Rats to Chlorpyrifos Elicits Sex-Selective Hyperlipidemia and Hyperinsulinemia in Adulthood

Developmental exposure to chlorpyrifos alters cell signaling both in the brain and in peripheral tissues, affecting the responses to a variety of neurotransmitters and hormones. We administered 1 mg/kg/day chlorpyrifos to rats on postnatal days 1–4, a regimen below the threshold for systemic toxicity. When tested in adulthood, chlorpyrifos-exposed animals displayed elevations in plasma cholesterol and triglycerides, without underlying alterations in nonesterified free fatty acids and glycerol. This effect was restricted to males. Similarly, in the postprandial state, male rats showed hyperinsulinemia in the face of normal circulating glucose levels but demonstrated appropriate reduction of circulating insulin concentrations after fasting. These outcomes and sex selectivity resemble earlier findings at the cellular level, which identified hepatic hyperresponsiveness to gluconeogenic inputs from β-adrenoceptors or glucagon receptors. Our results thus indicate that apparently subtoxic neonatal chlorpyrifos exposure, devoid of effects on viability or growth but within the parameters of human fetal or neonatal exposures, produce a metabolic pattern for plasma lipids and insulin that resembles the major adult risk factors for atherosclerosis and type 2 diabetes mellitus