bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of a vertical cavity quantum cascade phonon laser structure
Authors: Maryam W. , Akimov A. V. , Campion R. P. , Kent A. J.
Published: July 2013

Driven primarily by scientific curiosity, but also by the potential applications of intense sources of coherent sound, researchers have targeted the phonon laser (saser) since the invention of the optical laser over 50 years ago. Here we fabricate a vertical cavity structure designed to operate as a saser oscillator device at a frequency of 325 GHz. It is based on a semiconductor superlattice gain medium, inside a multimode cavity between two acoustic Bragg reflectors. We measure the acoustic output of the device as a function of time after applying electrical pumping. The emission builds in intensity reaching a steady state on a timescale of order 0.1 μs. We show that the results are consistent with a model of the dynamics of a saser cavity exactly analogous to the models used for describing laser dynamics. We also obtain estimates for the gain coefficient, steady-state acoustic power output and efficiency of the device.
Relationship between urinary sodium excretion and serum aldosterone in patients with diabetes in the presence and absence of modifiers of the renin–angiotensin–aldosterone system
Authors: Libianto Renata , Jerums George , Lam Que , Chen Angela , Baqar Sara , Pyrlis Felicity , Macisaac Richard J. , Moran John , Ekinci Elif I.
Published: July 2013

Although low dietary salt intake has beneficial effects on BP (blood pressure), low 24hUNa (24 h urinary sodium excretion), the most accurate estimate of dietary salt intake, is associated with increased mortality in people with diabetes. In the non-diabetic population, low salt intake is associated with increased RAAS (renin–angiotensin–aldosterone system) activity. In this cross-sectional study, we examined the relationship between 24hUNa, PRA (plasma renin activity), serum aldosterone and BNP (brain natriuretic peptide) in patients with diabetes. Clinical characteristics, 24hUNa, PRA, serum aldosterone and BNP were recorded in 222 consecutive patients (77% with Type 2 diabetes) attending a diabetes clinic at a tertiary hospital. The relationship between 24hUNa, serum aldosterone, PRA, BNP, urinary potassium excretion, serum potassium, serum sodium, eGFR (estimated glomerular filtration rate), urinary albumin excretion and HbA1c (glycated haemoglobin) was examined by a multivariable regression model. Levels of 24hUNa significantly predicted serum aldosterone in a linear fashion (R2=0.20, P=0.002). In the subgroup of patients (n=46) not taking RAAS-modifying agents, this relationship was also observed (R2=0.10, P=0.03), and the effect of 24hUNa on serum aldosterone was found to be more pronounced than in the whole cohort (coefficient=−0.0014, compared with −0.0008). There was no demonstrable relationship between 24hUNa and PRA or BNP. Low 24hUNa is associated with increased serum aldosterone in people with diabetes, in the presence and absence of RAAS-modifying agents. This raises the possibility that stimulation of the RAAS may be a mechanism that contributes to adverse outcomes observed in patients with low 24hUNa.
A compact hexapole state-selector for NO radicals
Authors: Kirste Moritz , Haak Henrik , Meijer Gerard , van de Meerakker Sebastiaan Y. T.
Published: July 2013

Focusing of molecular beams using an electrostatic hexapole is a mature technique to produce samples of state-selected molecules. The ability to efficiently focus molecules depends on the properties of the molecular species of interest, the length of the hexapole state selector, as well as on the maximum electric field strength that can be achieved in these devices. In particular for species with a small effective dipole moment such as nitric oxide (NO), hexapole state selectors of several meters in length are required to focus the beam. We report on a novel design for an electrostatic hexapole state-selector that allows for a maximum electric field strength of 260 kV/cm, reducing significantly the length of the hexapole that is required to focus the beam. We demonstrate the focusing of a molecular beam of NO radicals (X 2Π1/2, v = 0, J = 1/2, f) using a hexapole of only 30 cm length. A beamstop is integrated inside the hexapole at the geometric center of the device where the molecular trajectories have the largest deviation from the beam axis, effectively blocking the carrier gas of the molecular beam at minimum loss of NO density. The performance of the hexapole state-selector is investigated by state-selective laser induced fluorescence detection, as well as by two-dimensional imaging of the focused packet of NO radicals. The resulting packet of NO radicals has a density of 9 ± 3 × 1010 cm−3 and a state purity of 99%.
Stability of steady gravity waves generated by a moving localised pressure disturbance in water of finite depth
Authors: Grimshaw Roger , Maleewong Montri
Published: July 2013

We study the stability of the steady waves forced by a moving localised pressure disturbance in water of finite depth. The steady waves take the form of a downstream wavetrain for subcritical flow, but for supercritical flow there is a solution branch for each specified forcing term, which has two localised solitary-like solutions for each Froude number, a small-amplitude and a large-amplitude solution. Our main purpose is to numerically investigate the stability of these steady waves by simulating the unsteady development from appropriate initial conditions. We use a forced Korteweg-de Vries model valid in the transcritical regime for weak forcing, and a fully nonlinear boundary integral simulation. The simulations using the forced Korteweg-de Vries model are in good agreement with the fully nonlinear simulations when the Froude number is near unity for small pressure forcing, as expected. We find that the steady subcritical downstream wavetrain is stable. For supercritical flow, the small-amplitude solitary-like wave which has bifurcated from a uniform flow is stable, whereas the large-amplitude solitary-like wave which has bifurcated from a free solitary wave is unstable. Furthermore, here a difference between the forced Korteweg-de Vries model and the fully nonlinear simulations is revealed. For moderate and large pressure forcing, the forced Korteweg-de Vries model predicts a stable solitary wave moving away from the pressure forcing, while the nonlinear simulation shows that this wave evolves to a breaking wave.
Time-dependent experimental analysis of a thermal transpiration rarefied gas flow
Authors: Rojas-Cárdenas Marcos , Graur Irina , Perrier Pierre , Méolans J. Gilbert
Published: July 2013

Thermal transpiration is the macroscopic movement induced in a rarefied gas by a temperature gradient. The gas moves from the lower to the higher temperature zone. An original method is proposed here to measure the stationary mass flow rate of gas created by thermal transpiration in a micro-tube heated at its outlet. In addition, by means of a time-dependent study, parameters such as the pressure variation, the pressure variation speed, and the characteristic time of the system are analyzed. The experimental system is composed of a glass tube of circular cross section and two reservoirs positioned one at the inlet and one at the outlet of the capillary. The reservoirs are connected to two fast response time capacitance diaphragm gauges. By monitoring the pressure variation with time inside both reservoirs, it is possible to measure the macroscopic movement of the gas along the tube. Three gases, nitrogen, argon, and helium, are studied and three temperature differences ΔT = 37, 53.5, and 71 K are applied to the tube. The analyzed gas rarefaction conditions vary from near free molecular to slip regime. Finally, Poiseuille counter flows consistent with the experimental zero flow conditions of the thermal transpiration process are proved to be possible.
Stochastic-field cavitation model
Authors: Dumond J. , Magagnato F. , Class A.
Published: July 2013

Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian “particles” or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.
On the fly first principles study of the classical scattering of an Ar atom from the LiF(100) surface
Authors: Azuri Asaf , Pollak Eli
Published: July 2013

A density functional theory with dispersion corrections is used to study the scattering of an Ar atom on the LiF(100) surface. On the fly classical trajectories are propagated to study the in-plane angular and energy loss distributions of the scattered Ar atom. The computations are carried out for a frozen surface and a surface in which the crystal atoms are initially at T = 0 K. Two dimensional as well as three dimensional computations are presented. We find that the results agree qualitatively with measured experimental results. These computations show the impact of three dimensional effects on the scattering such as narrowing of the angular distance between rainbow peaks and inversion of asymmetry properties of the angular distribution. The computations also reaffirm the prediction that one should observe energy loss rainbows in the scattering of Ar from the LiF(100) surface.
The algebraic index theorem and deformation quantization of Lagrange-Finsler and Einstein spaces
Authors: Vacaru Sergiu I.
Published: July 2013

Various types of Lagrange and Finsler geometries, Einstein gravity, and modifications, can be modelled by nonholonomic distributions on tangent bundles/manifolds when the fundamental geometric objects are adapted to nonlinear connection structures. We can convert such geometries and physical theories into almost Kähler/Poisson structures on (co)tangent bundles. This allows us to apply deformation quantization formalism to almost symplectic connections induced by Lagrange–Finsler and/or Einstein fundamental geometric objects. There are constructed respective nonholonomic versions of the trace density maps for the zeroth Hochschild homology of deformation quantization of distinguished algebras (in this work, adapted to nonlinear connection structure). Our main result consists in an algebraic index theorem for Lagrange–Finsler and Einstein spaces. Finally, we show how the Einstein field equations for gravity theories and geometric mechanics models can be imbedded into the formalism of deformation quantization and index theorem.
Alteration of gas phase ion polarizabilities upon hydration in high dielectric liquids
Authors: Buyukdagli Sahin , Ala-Nissila T.
Published: July 2013

We investigate the modification of gas phase ion polarizabilities upon solvation in polar solvents and ionic liquids. To this aim, we develop a classical electrostatic theory of charged liquids composed of solvent molecules modeled as finite size dipoles, and embedding polarizable ions that consist of Drude oscillators. In qualitative agreement with ab initio calculations of polar solvents and ionic liquids, the hydration energy of a polarizable ion in both types of dielectric liquid is shown to favor the expansion of its electronic cloud. Namely, the ion carrying no dipole moment in the gas phase acquires a dipole moment in the liquid environment, but its electron cloud also reaches an enhanced rigidity. We find that the overall effect is an increase of the gas phase polarizability upon hydration. In the specific case of ionic liquids, it is shown that this hydration process is driven by a collective solvation mechanism where the dipole moment of a polarizable ion induced by its interaction with surrounding ions self-consistently adds to the polarization of the liquid, thereby amplifying the dielectric permittivity of the medium in a substantial way. We propose this self-consistent hydration as the underlying mechanism behind the high dielectric permittivities of ionic liquids composed of small charges with negligible gas phase dipole moment. Hydration being a correlation effect, the emerging picture indicates that electrostatic correlations cannot be neglected in polarizable liquids.
Enhancement of the maximum energy density in atomic layer deposited oxide based thin film capacitors
Authors: Spahr Holger , Nowak Christine , Hirschberg Felix , Reinker Johannes , Kowalsky Wolfgang , Hente Dirk , Johannes Hans-Hermann
Published: July 2013

Thin film capacitors on areas up to 6 mm2 have been measured regarding capacitance density, relative permittivity, and electrical breakdown. The maximum storable energy density of the thin film capacitors will be discussed as a parameter to evaluate the thin film capacitors applicability. Therefore the measurements of the layer thickness, capacitance density, and the breakdown voltage were combined to achieve the maximum storable areal and volume energy density depending on the dielectric layer thickness. Thickness dependent volume energy densities of up to 50 J/cm3 for pure Al2O3 and 60 J/cm3 for Al2O3/TiO2 nanolaminates were reached.
Effect of density of localized states on the ovonic threshold switching characteristics of the amorphous GeSe films
Authors: Ahn Hyung-Woo , Seok Jeong Doo , Cheong Byung-ki , Lee Hosuk , Lee Hosun , Kim Su-dong , Shin Sang-Yeol , Kim Donghwan , Lee Suyoun
Published: July 2013

We investigated the effect of nitrogen (N) doping on the threshold voltage of an ovonic threshold switching device using amorphous GeSe. Using the spectroscopic ellipsometry, we found that the addition of N brought about significant changes in electronic structure of GeSe, such as the density of localized states and the band gap energy. Besides, it was observed that the characteristics of OTS devices strongly depended on the doping of N, which could be attributed to those changes in electronic structure suggesting a method to modulate the threshold voltage of the device.
Effects of substrate-induced-strain on the electrical properties and laser induced voltages of tilted La0.67Ca0.33MnO3 thin films
Authors: Ma Ji , Zhang Hui , Chen Qingming , Liu Xiang
Published: July 2013

La0.67Ca0.33MnO3 thin films have been prepared on vicinal cut LaAlO3, (LaAlO3)0.3-(SrAlTaO6)0.7, and SrTiO3 (001) substrates by pulsed laser deposition. The influence of the substrate on the electrical transport properties and laser induced voltage (LIV) effect of the films was investigated. The high insulator to metal transition temperature Tp (263.6 K) and large peak voltage of LIV signal (2.328 V) were observed in the film grown on LaAlO3 substrate. The compressive strain and large Seebeck coefficient anisotropy ΔS (3.62 μV/K) induced by LaAlO3 are thought to be responsible for this result.
Exciton polarizability and absorption spectra in CdSe/ZnS nanocrystal quantum dots in electric fields
Authors: Wu Shudong , Xia Weiwei
Published: July 2013

The effects of an external electric field on the exciton polarizability and absorption spectra in CdSe/ZnS nanocrystal quantum dots have been investigated theoretically by using an exact diagonalization method within the effective-mass approximation. The results show that the application of an external electric field causes the splitting of degenerated states introducing new interband transitions (1s-1p0 and 1p0-1s), resulting in the increase of the excitonic absorption coefficients of the 1s-1p0 and 1p0-1s transitions due to the enhancement of the electric-field-induced coupling between the 1s and 1p0 states. The excitonic absorption intensity of 1s-1s, 1p-1-1p-1, and 1p1-1p1 transitions decreases with the increase of the electric field strength. A red-shift in the absorption spectra of 1s-1s, 1p-1-1p-1, 1p1-1p1, 1s-1p0, and 1p0-1s interband transitions is observed while the absorption peak of 1p0-1p0 interband transition is first blue-shifted and then red-shifted with increasing the electric field strength, which is attributed to the quantum-confined Stark effect (QCSE). The exciton polarizability increases monotonically with increasing the dot radius. The fitting expressions of the Stark shift and exciton polarizability have been proposed for the interband transitions in the strong confinement regime. Therefore, the emission wavelength and intensity of the output of optoelectronic nanodevices can be manipulated using an external electric field.
Increase of mobility in dual gate amorphous-InGaZnO4 thin-film transistors by pseudo-doping
Authors: Park Si Hyung , Mativenga Mallory , Jang Jin
Published: July 2013

Dual gate amorphous-InGaZnO4 (a-IGZO) thin-film transistors (TFTs) with a bottom gate that covers the whole channel and a top gate that covers only a small portion of the channel are investigated. It is shown that if the larger gate (bottom gate) is held at constant positive bias, while the smaller gate (top gate) drives the TFT, not only does the VTH shift negatively but the on-current also increases, resulting in dramatic increase in field-effect mobility (μFE). The μFE reaches ∼70 cm2/V·s with a bottom gate potential of 15 V—confirming that the carrier mobility of a-IGZO TFTs can be significantly increased by electron doping in the channel. In such a configuration, the larger bottom gate acts as an electron supplier—effectively raising the conductivity of the a-IGZO layer (pseudo-doping). The smaller one works in the usual way, which is to either deplete of or accumulate the channel with carriers.
Compressive-tensile deformation of nanocrystalline nickel at high pressure and temperature conditions
Authors: Yu Xiaohui , Wang Yuejian , Zhang Jianzhong , Xu Hongwu , Zhao Yusheng
Published: July 2013

We conducted uniaxial compressive and tensile deformation on nanocrystalline Ni at a confining pressure of 6 GPa and temperatures up to 900 °C. The determined compressive yield strength is 0.8 GPa, identical to the tensile yield strength obtained in the same deformation experiment, indicating that the Bauschinger effect is absent in nanocrystalline Ni. The yield strength obtained at 6 GPa is also comparable to that at ambient pressure, suggesting that the dislocation-mediated mechanisms are no longer activated during plastic deformation. Based on peak intensity and peak width analyses, grain rotation and grain growth are main factors underlying the plastic deformation.
Local probing of magnetoelectric coupling and magnetoelastic control of switching in BiFeO3-CoFe2O4 thin-film nanocomposite
Authors: Yan Feng , Chen Guannan , Lu Li , Finkel Peter , Spanier Jonathan E.
Published: July 2013

We report on the combination of piezoresponse force microscopy (PFM), magnetic force microscopy, and local ferroelectric switching with magnetic field for the study of a thin-film magnetoelectric (ME) nanocomposite. The collection of PFM under an applied variable magnetic field within a polycrystalline perovskite-spinel BiFeO3-CoFe2O4 (BFO-CFO) 0-3 type thin-film nanocomposite enables quantitative and proximal measurement of magnetoelastic strain-driven ME response. Combination of measurement of the as-grown strain state with local measurements of microstructure and macroscopic magnetization permits local mapping of ME coupling.
Periodic reversal of magneto-optic Faraday rotation on uniaxial birefringence crystal with ultrathin magnetic films
Authors: Su C. W. , Chang S. C. , Chang Y. C.
Published: July 2013

An experimental approach of inclined incidence magneto-optic Faraday effect observed in the polar plane is applied. Three samples containing ferromagnetic cobalt ultrathin films on a semiconductor zinc oxide (0001) single crystal substrate with in-plane and out-of-plane anisotropy are evaluated. Through the fine adjustment of crossed polarizers in the magneto-optic effect measurement completely recorded the detail optical and magneto-optical responses from the birefringent crystal substrate and the magnetic film, especially for the signal induced from the substrate with uniaxial optical axis. The angle dependency of interference phenomena periodically from the optical and magneto-optical responses is attributed to the birefringence even in the absence of a magnetic field. The new type of observation finds that the transmission Faraday intensity in the oblique incidence includes a combination of polarization rotations, which results from optical compensation from the substrate and magneto-optical Faraday effects from the film. The samples grown at different rates and examined by this method exhibit magnetic structure discriminations. This result can be applied in the advanced polarized-light technologies to enhance the spatial resolution of magnetic surfaces with microstructural information under various magnetic field direction.
Standing surface acoustic waves in LiNbO3 studied by time resolved X-ray diffraction at Petra III
Authors: Reusch T. , Schülein F. , Bömer C. , Osterhoff M. , Beerlink A. , Krenner H. J. , Wixforth A. , Salditt T.
Published: July 2013

We have carried out time resolved stroboscopic diffraction experiments on standing surface acoustic waves (SAWs) of Rayleigh type on a LiNbO3 substrate. A novel timing system has been developed and commissioned at the storage ring Petra III of Desy, allowing for phase locked stroboscopic diffraction experiments applicable to a broad range of timescales and experimental conditions. The combination of atomic structural resolution with temporal resolution on the picosecond time scale allows for the observation of the atomistic displacements for each time (or phase) point within the SAW period. A seamless transition between dynamical and kinematic scattering regimes as a function of the instantaneous surface amplitude induced by the standing SAW is observed. The interpretation and control of the experiment, in particular disentangling the diffraction effects (kinematic to dynamical diffraction regime) from possible non-linear surface effects is unambiguously enabled by the precise control of phase between the standing SAW and the synchrotron bunches. The example illustrates the great flexibility and universality of the presented timing system, opening up new opportunities for a broad range of time resolved experiments.
Competitive In and Ga incorporations for InxGa1-xN (0.29<x<0.36) nanorods grown at a moderate temperature
Authors: Hamad S. M. , Norman D. P. , Chen Q. Y. , Keles F. , Seo H. W.
Published: July 2013

The kinetics of In and Ga incorporation into wurtzite InxGa1−xN nanorods, grown by plasma-assisted MBE under N-rich conditions at a moderate temperature, has been systematically investigated with Ga-flux set as a growth parameter at three distinct values while varying In-flux. The interplay of Ga and In fluxes in their contributions to the incorporation was found to disagree with the empirical Böttcher's formula, of which the reliability is based on the assumption of preeminent Ga incorporation. The competition between Ga and In for incorporations involves, we believe, the displacement of In from the weaker In-N bonds by Ga to form the Ga-N bonds at high In and Ga fluxes.
Diffusion coefficients of fluorescent organic molecules in inert gases
Authors: Rolin Cedric , Forrest Stephen R.
Published: July 2013

We use arrested-flow pulse broadening to measure the diffusion coefficients of four archetype organic semiconductors in two carrier gases, N2 and Ar, with a precision of 5%. The measurements are realized by the injection and transport of pulses of organic molecules in an organic vapor phase deposition chamber, followed by their detection using laser induced fluorescence that dynamically measures the organic concentration in the gas phase. Measurements show that the diffusivity of tris(8-hydroxyquinoline) aluminum (Alq3) in N2 and Ar varies as the square of the temperature and inversely with pressure over a large range of gas conditions. We show that classical Chapman-Enskog theory can be used to approximate the diffusivity with an accuracy that depends on the physical dimensions of the organic molecular species, with the most accurate predictions for spherical and rigid molecules such as Alq3.
The influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 4. Gastrointestinal parasitism
Authors: McGregor B. A. , Presidente P. J. A. , Campbell N. J.
Published: July 2013

Gastrointestinal nematodes limit the growth, production and welfare of goats but there are few reliable sources of information for recommending management practices across flocks. The effects of animal species (Angora goat, Merino sheep, mixed-grazed goats and mixed-grazed sheep at the ratio of 1 : 1) and stocking rate (SR: 7.5, 10, 12.5 animals/ha) on gastrointestinal parasitism were determined in a replicated experiment on improved annual temperate pastures in southern Australia, from 1981 to 1984. Detailed monitoring of gastrointestinal nematodes was undertaken on animals before, during (five times per year) and at the conclusion of studies using faecal strongyle egg counts (WEC) and total worm counts. Sheep had a greater proportion of nematodes as Teladorsagia spp. and goats a greater incidence of Trichostrongylus spp. Both goats and sheep developed resistance to Nematodirus spp. during the experiment. WEC was similar in goats and sheep at the start of the experimental period but, thereafter, was consistently greater in goats than in sheep. While WEC was highly related to total worm count, the regressions for sheep and goats were different. Increasing the SR increased the WEC of goats and mixed-grazed goats but not of sheep. During the experiment, WEC declined at 7 and 10 animals/ha but increased at 12.5/ha. Mixed grazing with goats provided beneficial effects for sheep at all stocking rates, but the effects for goats were dependent on the stocking rate, being beneficial at 7.5 and 10/ha but harmful at 12.5/ha. The WEC of separately grazed goats were generally higher than the WEC of mixed grazed goats. The WEC of mixed sheep were lower than those of separately grazed sheep. During the experiment, the WEC of mixed grazed sheep declined faster than the WEC of separately grazed sheep but the WEC of separately grazed goats at 12.5/ha and of mixed grazed goats at 10 and 12.5/ha increased. Under the environmental and pastoral conditions examined, Angora wether goats should not be grazed at SR above those recommended for wether sheep. In the present study, the impact of gastrointestinal-nematode infections in goats was reduced at lower SR. Further, mixed grazing of Angora wether goats with wether sheep at or below the recommended SR resulted in reduced gastrointestinal parasitism for both sheep and goats, compared with monospecific grazing conditions. Goats did not represent a gastrointestinal-nematode hazard to sheep.
Variations in atmospheric CO2growth rates coupled with tropical temperature
Authors: Wang Weile , Ciais Philippe , Nemani Ramakrishna R. , Canadell Josep G. , Piao Shilong , Sitch Stephen , White Michael A. , Hashimoto Hirofumi , Milesi Cristina , Myneni Ranga B.
Published: July 2013

Previous studies have highlighted the occurrence and intensity of El Niño–Southern Oscillation as important drivers of the interannual variability of the atmospheric CO2growth rate, but the underlying biogeophysical mechanisms governing such connections remain unclear. Here we show a strong and persistent coupling (r2≈ 0.50) between interannual variations of the CO2growth rate and tropical land–surface air temperature during 1959 to 2011, with a 1 °C tropical temperature anomaly leading to a 3.5 ± 0.6 Petagrams of carbon per year (PgC/y) CO2growth-rate anomaly on average. Analysis of simulation results from Dynamic Global Vegetation Models suggests that this temperature–CO2coupling is contributed mainly by the additive responses of heterotrophic respiration (Rh) and net primary production (NPP) to temperature variations in tropical ecosystems. However, we find a weaker and less consistent (r2≈ 0.25) interannual coupling between CO2growth rate and tropical land precipitation than diagnosed from the Dynamic Global Vegetation Models, likely resulting from the subtractive responses of tropical Rh and NPP to precipitation anomalies that partly offset each other in the net ecosystem exchange (i.e., net ecosystem exchange ≈ Rh − NPP). Variations in other climate variables (e.g., large-scale cloudiness) and natural disturbances (e.g., volcanic eruptions) may induce transient reductions in the temperature–CO2coupling, but the relationship is robust during the past 50 y and shows full recovery within a few years after any such major variability event. Therefore, it provides an important diagnostic tool for improved understanding of the contemporary and future global carbon cycle.
Prevalence and Predictors of Compliance with Discontinuation of Airborne Isolation in Patients with Suspected Pulmonary Tuberculosis
Authors: Thomas Benjamin S. , Bello Erlaine F. , Seto Todd B.
Published: July 2013

Objective.

Examine the use of airborne isolation by identifying reasons for nontimely discontinuation and predictors of compliance with Centers for Disease Control and Prevention (CDC) guidelines. Compliance with guidelines should result in timely (within 48 hours) discontinuation of isolation in patients without infectious pulmonary tuberculosis (TB).

Design.

Retrospective, observational study.

Setting.

A private, university-affiliated, tertiary-care medical center.

Patients.

All patients in airborne isolation for suspected pulmonary TB from June through December 2011.

Method.

Chart reviews were performed to identify airborne isolation practices and delayed (greater than 48 hours) or very delayed (greater than 72 hours) discontinuation. We used descriptive statistics and logistic regression to determine independent predictors of nontimely discontinuation of isolation.

Results.

We identified 113 patients (mean age ± standard deviation, 59.8 ± 17.7 years; male sex, 75.2%; white race, 15.9%; mean collection interval ± standard deviation, 21.4 ± 12.9 hours). Delayed and very delayed isolation discontinuation was noted in 81% and 49% of patients, respectively. No significant differences in demographic characteristics and clinical characteristics were identified between groups. Predictors of timely (within 48 hours) airborne isolation discontinuation included use of alternate diagnosis for discontinuation of isolation (P = .02), early infectious diseases (ID) consultation (P = .03), pulmonary consultation (P = .02), average sputum collection interval less than 24 hours (P = .03), and need for more than 1 induced sputum specimen (P = .05). Adjusting for potential confounders, pulmonary consultation (odds ratio [OR] [95% confidence interval (CI)], 0.14 [0.03-0.58]), alternate diagnosis for discontinuation of isolation (OR [95% CI], 4.5 [1.3-15.8]), and early ID consultation (OR [95% CI], 4.0 [1.1-14.8]) were independently associated with timely discontinuation.

Conclusions.

Timely airborne isolation discontinuation occurs in only 18.6% of cases and is an opportunity for cost savings, improved efficiency, and potentially patient safety and satisfaction.
Secular Trends in Gram-Negative Resistance among Urinary Tract Infection Hospitalizations in the United States, 2000–2009
Authors: Zilberberg Marya D. , Shorr Andrew F.
Published: July 2013

Objective.

Urinary tract infections (UTIs) are common among hospitalized patients. Selection of an appropriate antibiotic for this infection requires knowledge of both its general microbiology and the epidemiology of drug-resistant organisms. We sought to determine secular trends in UTI hospitalizations that involve gram-negative (GN) multidrug-resistant Pseudomonas aeruginosa (MDR-PA), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (EC) and Klebsiella pneumoniae(KP), and carbapenem-resistant Enterobacteriaceae (CRE).

Design.

Survey.

Patients.

Patients with UTI in US hospitals between 2000 and 2009.

Methods.

We first derived the total number of UTI hospitalizations in the United States from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample database years 2000–2009. Based on a literature review, we then determined what proportion of all UTIs arise due to each of the organisms of interest, irrespective of resistance pattern. Finally, we assessed the prevalence of resistance within each pathogen based on the Eurofins Surveillance Network database 2000–2009. Susceptibility patterns served as phenotypic surrogates for resistance.

Results.

Between 2000 and 2009, the frequency of UTI hospitalizations increased by approximately 50%, from 53 to 77 cases per 1,000 hospitalizations. Infections due to all GN bacteria followed a similar trajectory, whereas those caused by resistant GN pathogens increased by approximately 50% (MDR-PA) to approximately 300% (ESBL). CRE emerged and reached 0.5 cases per 1,000 hospitalizations in this 10-year period.

Conclusions.

The epidemiology and microbiology of GN UTI hospitalizations has shifted over the past decade. The proportion of all hospitalizations involving this infection has climbed. Resistant GN bacteria are becoming more prevalent and are implicated in an increasing proportion of UTIs among hospitalized patients.
A new role for RINT-1 in SNARE complex assembly at thetrans-Golgi network in coordination with the COG complex
Authors: Arasaki Kohei , Takagi Daichi , Furuno Akiko , Sohda Miwa , Misumi Yoshio , Wakana Yuichi , Inoue Hiroki , Tagaya Mitsuo
Published: July 2013

Docking and fusion of transport vesicles/carriers with the target membrane involve a tethering factor–mediated initial contact followed by soluble N-ethylmaleimide–sensitive factor attachment protein receptor (SNARE)–catalyzed membrane fusion. The multisubunit tethering CATCHR family complexes (Dsl1, COG, exocyst, and GARP complexes) share very low sequence homology among subunits despite likely evolving from a common ancestor and participate in fundamentally different membrane trafficking pathways. Yeast Tip20, as a subunit of the Dsl1 complex, has been implicated in retrograde transport from the Golgi apparatus to the endoplasmic reticulum. Our previous study showed that RINT-1, the mammalian counterpart of yeast Tip20, mediates the association of ZW10 (mammalian Dsl1) with endoplasmic reticulum–localized SNARE proteins. In the present study, we show that RINT-1 is also required for endosome-to–trans-Golgi network trafficking. RINT-1 uncomplexed with ZW10 interacts with the COG complex, another member of the CATCHR family complex, and regulates SNARE complex assembly at the trans-Golgi network. This additional role for RINT-1 may in part reflect adaptation to the demand for more diverse transport routes from endosomes to the trans-Golgi network in mammals compared with those in a unicellular organism, yeast. The present findings highlight a new role of RINT-1 in coordination with the COG complex.
WASH is required for lysosomal recycling and efficient autophagic and phagocytic digestion
Authors: King Jason S. , Gueho Aurélie , Hagedorn Monica , Gopaldass Navin , Leuba Florence , Soldati Thierry , Insall Robert H.
Published: July 2013

Wiskott-Aldrich syndrome protein and SCAR homologue (WASH) is an important regulator of vesicle trafficking. By generating actin on the surface of intracellular vesicles, WASH is able to directly regulate endosomal sorting and maturation. We report that, in Dictyostelium, WASH is also required for the lysosomal digestion of both phagocytic and autophagic cargo. Consequently, Dictyostelium cells lacking WASH are unable to grow on many bacteria or to digest their own cytoplasm to survive starvation. WASH is required for efficient phagosomal proteolysis, and proteomic analysis demonstrates that this is due to reduced delivery of lysosomal hydrolases. Both protease and lipase delivery are disrupted, and lipid catabolism is also perturbed. Starvation-induced autophagy therefore leads to phospholipid accumulation within WASH-null lysosomes. This causes the formation of multilamellar bodies typical of many lysosomal storage diseases. Mechanistically, we show that, in cells lacking WASH, cathepsin D becomes trapped in a late endosomal compartment, unable to be recycled to nascent phagosomes and autophagosomes. WASH is therefore required for the maturation of lysosomes to a stage at which hydrolases can be retrieved and reused.
Identification and characterization ofDrosophilaSnurportin reveals a role for the import receptor Moleskin/importin-7 in snRNP biogenesis
Authors: Natalizio Amanda Hicks , Matera A. Gregory
Published: July 2013

Nuclear import is an essential step in small nuclear ribonucleoprotein (snRNP) biogenesis. Snurportin1 (SPN1), the import adaptor, binds to trimethylguanosine (TMG) caps on spliceosomal small nuclear RNAs. Previous studies indicated that vertebrate snRNP import requires importin-β, the transport receptor that binds directly to SPN1. We identify CG42303/snup as the Drosophila orthologue of human snurportin1 (SNUPN). Of interest, the importin-β binding (IBB) domain of SPN1, which is essential for TMG cap–mediated snRNP import in humans, is not well conserved in flies. Consistent with its lack of an IBB domain, we find that Drosophila SNUP (dSNUP) does not interact with Ketel/importin-β. Fruit fly snRNPs also fail to bind Ketel; however, the importin-7 orthologue Moleskin (Msk) physically associates with both dSNUP and spliceosomal snRNPs and localizes to nuclear Cajal bodies. Strikingly, we find that msk-null mutants are depleted of the snRNP assembly factor, survival motor neuron, and the Cajal body marker, coilin. Consistent with a loss of snRNP import function, long-lived msk larvae show an accumulation of TMG cap signal in the cytoplasm. These data indicate that Ketel/importin-β does not play a significant role in Drosophila snRNP import and demonstrate a crucial function for Msk in snRNP biogenesis.
Thinking Equality Today: Badiou, Rancière, Nancy
Authors: Watkin Christopher
Published: July 2013

Recent work on Alain Badiou and Jacques Rancière has rightly identified equality both as a central theme in their own thinking and as the key notion in contemporary radical political thought more broadly, but a focus on the differences between their respective accounts of equality has failed to clarify a major problem that they share. The problem is that human equality is said to rest on a particular human capacity, leaving Badiou's axiomatic equality and Rancière's assumed equality vulnerable to the charge of having a blind spot for some of society's most vulnerable. This article introduces an alternative understanding of equality drawn from the thought of Jean-Luc Nancy, an equality that does not rely on a human capacity to guarantee or verify it but rests on Nancy's notion of sense. The article explores the advantages of Nancy's account of equality in relation to sense over and against an alternative reading that focuses on Nancy's evocation of the suffering human body, before addressing, in conclusion, the problems with which Nancy's idea of equality will have to grapple, and why, despite these problems, it is still preferable to the Badiouian and Rancièrian approaches.
La Captation théâtrale, le plus pur des théâtres? Le cas d'
‘Art’
de Yasmina Reza
Authors: Jaccomard Hélène
Published: July 2013

En son temps, André Bazin avait comparé sur le plan de leur théâtralité respective le théâtre et le théâtre
filmé
, expression qui recouvrait les films tirés de textes théâtraux aboutissant parfois à des ‘croisements féconds’, c'est-à-dire à un cinéma et un théâtre
impurs
. Ce qui est plus courant de nos jours, c'est le théâtre
capté
, lorsqu'une représentation enregistrée en public est montée sous forme de film pour être retransmise au cinéma, à la télévision ou diffusée sur support numérique. Une réflexion sur la théâtralité de ce type de film est encore à faire. En se référant aux remarquables intuitions de Bazin, le présent article se propose de jeter les bases d'une analyse théorique et pratique du théâtre capté, en étudiant le langage cinématographique de la captation d'une pièce à succès,
‘Art’
de Yasmina Reza, c'est-à-dire sa bande-image et sa bande-son. On s'interroge au final sur la question du plaisir devant le film de la captation, qui restitue fidèlement les réactions sonores de la salle de théâtre.
Crystal structure of Junin virus nucleoprotein
Authors: Zhang Yinjie , Li Le , Liu Xiang , Dong Shishang , Wang Wenming , Huo Tong , Guo Yu , Rao Zihe , Yang Cheng
Published: July 2013

Junin virus (JUNV) has been identified as the aetiological agent of Argentine haemorrhagic fever (AHF), which is a serious public health problem with approximately 5 million people at risk. It is treated as a potential bioterrorism agent because of its rapid transmission by aerosols. JUNV is a negative-sense ssRNA virus that belongs to the genus Arenavirus within the family Arenaviridae, and its genomic RNA contains two segments encoding four proteins. Among these, the nucleoprotein (NP) has essential roles in viral RNA synthesis and immune suppression, but the molecular mechanisms of its actions are only partially understood. Here, we determined a 2.2 Å crystal structure of the C-terminal domain of JUNV NP. This structure showed high similarity to the Lassa fever virus (LASV) NP C-terminal domain. However, both the structure and function of JUNV NP showed differences compared with LASV NP. This study extends our structural insight into the negative-sense ssRNA virus NPs.
Agricultural risks and risk management in the current context of Chinese economy
Authors: Holly Wang H.
Published: July 2013

Purpose

The purpose of this paper is to provide a big picture of the current context of Chinese economy, the government policies on agriculture, and the role of agricultural risks and risk management against this background.

Design/methodology/approach

The new Chinese economic challenges are laid out upfront. Relevant agricultural issues are then provided, with statistics; next, risks and risk management topics are introduced and controversial issues in agriculture are discussed. Relevant policies reflected in the State Council's No. 1 documents in both 2012 and 2013 are introduced and filled in each section.

Findings

The Chinese economy may slow down after decades of fast development. Food security is still a top priority, even with the income rise. Increased labor cost may transform Chinese agriculture from the traditional labor intensive field management into a modern agriculture characterized by high input use and larger scale.

Research limitations/implications

The research implication is directing economists focusing on Chinese agricultural risks to grasp the opportunity of the Chinese government investing in agricultural research and development, to look more broadly, to involve multidisciplinary research with the natural sciences, and to refer to the situation of modern agriculture.

Practical implications

There are some policy implications. Further liberalization of land ownership is called for, as is the development of infrastructure.

Originality/value

This paper addresses the objectives in putting agricultural risks and risk management into the overall big picture of the Chinese economy and government policies.
Modelling “shallow loss” crop revenue programs
Authors: Paulson Nicholas D. , Woodard Joshua D. , Babcock Bruce
Published: July 2013

Purpose

The purpose of this paper is to investigate changes proposed in 2012 to commodity programs for the new Farm Bill. Both the Senate and House Agriculture Committee versions of the new Farm Bill eliminate current commodity programs including direct payments, create new revenue‐based commodity program options designed to cover “shallow” revenue losses, and also introduce supplemental crop insurance coverage for shallow revenue losses.

Design/methodology/approach

This paper documents the payment functions for the new revenue programs proposed in both the Senate and House Ag Committee Farm Bills, and also estimates expected payments for each using a model based on historical county yield data, farmer‐level risk rates from RMA, and commodity price levels from the March 2012 CBO baseline projections.

Findings

The authors find significant variation in expected per acre payment across programs, crops, and regions. In general, the Senate's bill would be expected to be preferred over the House's bill for corn and soybean producers, particularly those in the Midwest. Also, the RLC program in the House's Bill typically would be projected to pay much less than the Senate's SCO or ARC programs for most producers in the Midwest.

Originality/value

This study develops an extensive nationwide model of county and farm yield and price risks for the five major US crops and employs the model to evaluate expected payment rates and the distribution of payments under the House and Senate Farm Bill proposals. These analyses are important for program evaluation and should be of great interest to producers and policymakers.
Gender issues for people with intellectual disabilities and mental health problems: asking what service users and staff think
Authors: Stenfert Kroese Biza , Rose John , Heer Kuljit , O’Brien Alexis
Published: July 2013

Purpose

The current qualitative study aims to investigate service users’, support staff's and community team members’ views of gender differences in cause and presentation of mental health problems, whether current services respond differently to men and women with mental health problems and areas in which services can become more gender sensitive.

Design/methodology/approach

Two focus groups were conducted with service users with intellectual disabilities and mental health problems in addition to two focus groups with a variety of staff. Subsequently, individual interviews were conducted with both male and female staff members employed in residential and community intellectual disability services. The number of participants totalled 54 (16 service users and 38 staff). Thematic analysis was adopted in order to identify dominant themes in the discourse of these stakeholder groups.

Findings

The analysis produced a number of themes which include: compliance versus challenge; vulnerability; expression of emotion; gender equality; same sex support; caring qualities; and boundaries.

Originality/value

A number of suggestions for improving services are discussed in the context of the current findings.