bluuebunny/crossref_metadata_2025 huggingface dataset:
Shock experiments on anhydrite and new constraints on the impact‐induced SOx release at the K‐Pg boundary
Authors: PRESCHER Clemens , LANGENHORST Falko , HORNEMANN Ulrich , DEUTSCH Alexander
Published: October 2011

Abstract– We have performed six shock experiments at nominal peak‐shock pressures of 12.5, 20, 33, 46.5, 64, and 85 GPa using polycrystalline anhydrite discs embedded in ARMCO‐Fe sample containers and the shock reverberation technique. The recovered samples were analyzed using X‐ray powder diffraction and transmission electron microscopy (TEM). The X‐ray diffraction patterns recorded on all samples are compatible with the anhydrite structure; extra‐peaks have not been observed. Peak intensities decrease and peak broadening increases progressively in the pressure range from 0 to 46.5 GPa. At higher pressures, peak broadening diminishes and the X‐ray diffraction pattern of the 85 GPa sample resembles essentially that of unshocked, well‐crystallized anhydrite. Related structural changes at the nanoscale include in the pressure regime up to 20 GPa “cold” deformation phenomena such as cracks and deformation twins. Dislocation density increases up to 33 GPa and the strain increases up to 46.5 GPa. In the pressure range from 46.5 to 85 GPa, high postshock temperatures caused annealing of the deformation features. Increasing density and size of voids in the anhydrite samples shocked at 64 and 85 GPa indicate partial decomposition of anhydrite. Recalculation of the peak‐shock pressure in the experiments to a more realistic natural loading path indicates the onset of degassing of anhydrite in the pressure range of 30–41 GPa.
Heterogeneous distributions of amino acids provide evidence of multiple sources within the Almahata Sitta parent body, asteroid 2008 TC3
Authors: BURTON Aaron S. , GLAVIN Daniel P. , CALLAHAN Michael P. , DWORKIN Jason P. , JENNISKENS Peter , SHADDAD Muawia H.
Published: October 2011

Abstract– Two new fragments of the Almahata Sitta meteorite and a sample of sand from the related strewn field in the Nubian Desert, Sudan, were analyzed for two to six carbon aliphatic primary amino acids by ultrahigh performance liquid chromatography with UV‐fluorescence detection and time‐of‐flight mass spectrometry (LC‐FT/ToF‐MS). The distribution of amino acids in fragment #25, an H5 ordinary chondrite, and fragment #27, a polymict ureilite, were compared with results from the previously analyzed fragment #4, also a polymict ureilite. All three meteorite fragments contain 180–270 parts‐per‐billion (ppb) of amino acids, roughly 1000‐fold lower than the total amino acid abundance of the Murchison carbonaceous chondrite. All of the Almahata Sitta fragments analyzed have amino acid distributions that differ from the Nubian Desert sand, which primarily contains l‐α‐amino acids. In addition, the meteorites contain several amino acids that were not detected in the sand, indicating that many of the amino acids are extraterrestrial in origin. Despite their petrological differences, meteorite fragments #25 and #27 contain similar amino acid compositions; however, the distribution of amino acids in fragment #27 was distinct from those in fragment #4, even though both are polymict ureilites from the same parent body. Unlike in CM2 and CR2/3 meteorites, there are low relative abundances of α‐amino acids in the Almahata Sitta meteorite fragments, which suggest that Strecker‐type chemistry was not a significant amino acid formation mechanism. Given the high temperatures that asteroid 2008 TC3 appears to have experienced and lack of evidence for aqueous alteration on the asteroid, it is possible that the extraterrestrial amino acids detected in Almahata Sitta were formed by Fischer‐Tropsch/Haber‐Bosch type gas‐grain reactions at elevated temperatures.
Heat Transfer Characteristics of an Impinging Jet in Crossflow
Authors: Wang Lei , Sundén Bengt , Borg Andreas , Abrahamsson Hans
Published: October 2011

The heat transfer characteristics of an impinging jet into a crossflow have been investigated by the liquid crystal thermography technique. The jet nozzle is circular and is inclined at 10 deg with respect to the target wall. In a turbulent flow regime, the effects of the jet Reynolds number, the velocity ratio, and the crossflow Reynolds number on the heat transfer are examined. The results show that the heat transfer patterns are strongly affected by the jet Reynolds number and the velocity ratio. For a given jet Reynolds number, it is found that the crossflow diminishes the peak Nusselt number in the jet impingement region. However, in the wall jet region, the results suggest that the local heat transfer is nearly independent of the crossflow Reynolds number.
Multiscale Part-Spectrum k-Distribution Database for Atomic Radiation in Hypersonic Nonequilibrium Flows
Authors: Bansal Ankit , Modest Michael
Published: October 2011

An accurate and compact part-spectrum k-distribution database has been developed for the two most important radiating species N and O encountered in hypersonic nonequilibrium flows. The database allows users to calculate the desired full-spectrum k-distributions through look-up and interpolation, providing an efficient means to perform radiative transfer calculations. A detailed methodology of the k-distribution data generation is presented. An optimized Gauss quadrature scheme is implemented for reducing the size of the database. The accuracy of the database is determined by comparing part-spectrum emissivities with those obtained from line-by-line calculations. The application of the database to construct full-spectrum k-distributions at arbitrary gas states is discussed. Heat transfer results for the stagnation line of the Stardust vehicle are discussed and CPU-time studies are presented, demonstrating the accuracy and efficiency of the k-distribution database.
Measurement and Modeling of Confined Jet Discharged Tangentially on a Concave Semicylindrical Hot Surface
Authors: Hamdan Mohammad O. , Elnajjar Emad , Haik Yousef
Published: October 2011

The paper investigates experimentally and numerically the heat transfer augmentation from a semicircular heated surface due to confined slot-jet impingement. For different Reynolds numbers, the average and local Nusselt numbers are calculated by reporting the heater thermal image obtained by an infrared camera, the inlet and outlet flow temperature via thermocouples, the flow rate via rotameter, and the pressure drop across the inlet and outlet flow via pressure transducers. The single enclosed jet flow is used to create a single cyclone inside the internal semicircular channel to promote the heat transfer at different jet Reynolds numbers (Rejet = 1000–5000). Three turbulence models, namely, the standard k – ɛ, k – ω and the Reynolds stress model (RSM) have been investigated in the present paper by comparing Nusselt number and normalized pressure drop distribution against the experimental data, helping ascertain on the relative merits of the adopted models. The computational fluid dynamics results show that the RSM turbulent model reasonably forecast the experimental data.
Growth mechanism of multilayer-graphene-capped, vertically aligned multiwalled carbon nanotube arrays
Authors: Matsuoka Yuki , Clark Ian T. , Yoshimura Masamichi
Published: October 2011

The authors describe a rigorous investigation of the growth mechanism of composite structures consisting of graphene multilayers supported by vertically aligned multiwalled carbon nanotubes (VA-MWCNTs). The synthesis was performed via chemical vapor deposition with ethanol as a carbon source and iron films ranging in thickness from 1 to 9 nm as the catalyst. The morphology of grown films was investigated using scanning electron microscopy and transmission electron microscopy (TEM), and the crystallinity was studied using TEM and Raman spectroscopy. Thicker Fe films (8 or 9 nm) yielded composite structures, thin Fe films (1 to 4 nm) produced pure VA-MWCNTs, and Fe layers between 5 and 7 nm produced an intermediate structure composed of bundles of VA-MWCNTs fused together at their tips. The authors present growth mechanisms for all three structures. The authors attribute the change from VA-MWCNT to intermediate/composite with higher Fe film thicknesses to the formation of graphitic layers at the initial growth stage.
Zirconium nitride films deposited in (Ar + N2 + H2) sputtering atmosphere: Optical, structural, and electrical properties
Authors: Signore M. A. , Valerini D. , Tapfer L. , Caretto G. , Rizzo A.
Published: October 2011

Zr–N films were grown on glass substrates via radio-frequency magnetron sputtering using an Ar + N2 + H2 mixture. Hydrogen was employed in order to reduce oxygen contamination coming from background pressure, as confirmed by secondary ion mass spectroscopy analysis. The tuned process parameter was the nitrogen flux percentage (RN2) in the mixture. The crystallographic structure of the films was studied using x-ray diffraction. The measurements show that the films deposited at low RN2 (lower than or equal to 50%) crystallize in the rocksalt ZrN structure. As RN2 exceeds 50%, the film exhibits the co-presence of ZrN and Zr3N4 (denoted as o-Zr3N4) phases. When the deposition is performed in only nitrogen atmosphere (RN2 = 100%), a broad peak located at 2θ ≈ 32.2° is mainly attributed to the contribution coming from (320) planes of the o-Zr3N4. An envelope method, based on the optical reflection and transmission spectra taken at normal incidence, has been applied for the optical characterization of the nitride films. Such a method allows the determination of the samples’ average thickness and optical constants (refractive index n and extinction coefficient k) in the ultraviolet-visible-near infrared regions. The evaluated thickness was about 2500 nm, which is in good agreement with the value obtained from profilometry. The absorption coefficient α was calculated from reflectance and transmittance spectra. The energy bandgap ranges from 2.3 eV to 2.4 eV. Electrical characterization was performed using capacitance-voltage measurements, which showed that the films evolve from insulating to semiconductor behavior when the nitrogen content in the sputtering atmosphere is decreased, confirming structural and optical results.
PEN/Si3N4 bilayer film for dc bus capacitors in power converters in hybrid electric vehicles
Authors: Zou Chen , Zhang Qiming , Zhang Shihai , Kushner Douglas , Zhou Xin , Bernard Richard , Orchard Raymond J.
Published: October 2011

High performance hybrid bilayer capacitor film has been developed by controlled deposition of silicon nitride (Si3N4) on polyethylene naphthalate (PEN). It was found that silicon nitride prepared with plasma-enhanced chemical vapor deposition can significantly increase the dielectric constant (K) and energy density of PEN by more than 20% and 50%, respectively. Moreover, the PEN/Si3N4 bilayer hybrid film also exhibits appropriate mechanical and thermal properties for capacitor winding. The high operating temperature and energy density of the PEN/Si3N4 bilayer dielectric film are very attractive for dc bus capacitors used in power inverters or converters found in hybrid electric vehicles, wind turbine generators, grid-tied photovoltaics, and smart grid, as well as pulsed power systems.
Stochastic Pulse Regulation in Bacterial Stress Response
Authors: Locke James C. W. , Young Jonathan W. , Fontes Michelle , Jiménez María Jesús Hernández , Elowitz Michael B.
Published: October 2011

Energy stress activates an alternative sigma factor in stochastic pulses and modulates pulse frequency to control activity.
The Influence of Late Quaternary Climate-Change Velocity on Species Endemism
Authors: Sandel B. , Arge L. , Dalsgaard B. , Davies R. G. , Gaston K. J. , Sutherland W. J. , Svenning J.-C.
Published: October 2011

Regions with low glacial-interglacial climate-change velocity were essential refuges for many small-ranged species.
Inspiratory muscle training lowers the oxygen cost of voluntary hyperpnea
Authors: Turner Louise A. , Tecklenburg-Lund Sandra L. , Chapman Robert F. , Stager Joel M. , Wilhite Daniel P. , Mickleborough Timothy D.
Published: October 2011

The purpose of this study was to determine if inspiratory muscle training (IMT) alters the oxygen cost of breathing (V̇o2RM) during voluntary hyperpnea. Sixteen male cyclists completed 6 wk of IMT using an inspiratory load of 50% (IMT) or 15% placebo (CON) of maximal inspiratory pressure (Pimax). Prior to training, a maximal incremental cycle ergometer test was performed to determine V̇o2and ventilation (V̇E) at multiple workloads. Pre- and post-training, subjects performed three separate 4-min bouts of voluntary eucapnic hyperpnea (mimic), matching V̇Ethat occurred at 50, 75, and 100% of V̇o2 max. Pimaxwas significantly increased ( P < 0.05) by 22.5 ± 8.7% from pre- to post-IMT and remained unchanged in the CON group. The V̇o2RMrequired during the mimic trial corresponded to 5.1 ± 2.5, 5.7 ± 1.4, and 11.7% ± 2.5% of the total V̇o2(V̇o2T) at ventilatory workloads equivalent to 50, 75, and 100% of V̇o2 max, respectively. Following IMT, the V̇o2RMrequirement significantly decreased ( P < 0.05) by 1.5% (4.2 ± 1.4% of V̇o2T) at 75% V̇o2 maxand 3.4% (8.1 ± 3.5% of V̇o2T) at 100% V̇o2 max. No significant changes were shown in the CON group. IMT significantly reduced the O2cost of voluntary hyperpnea, which suggests that a reduction in the O2requirement of the respiratory muscles following a period of IMT may facilitate increased O2availability to the active muscles during exercise. These data suggest that IMT may reduce the O2cost of ventilation during exercise, providing an insight into mechanism(s) underpinning the reported improvements in whole body endurance performance; however, this awaits further investigation.
Akt/mTOR Counteract the Antitumor Activities of Cixutumumab, an Anti-Insulin–like Growth Factor I Receptor Monoclonal Antibody
Authors: Shin Dong Hoon , Min Hye-Young , El-Naggar Adel K. , Lippman Scott M. , Glisson Bonnie , Lee Ho-Young
Published: October 2011

Recent reports have shown limited anticancer therapeutic efficacy of insulin-like growth factor receptor (IGF-1R)-targeted monoclonal antibodies (mAb), but the resistance mechanisms have not been completely identified. Because cooperation between epidermal growth factor receptor (EGFR) and IGF-IR could cause resistance to inhibitors of individual receptor tyrosine kinases, we investigated the involvement of EGFR signaling in resistance to IGF-1R mAb and the underlying mechanisms of action. Most head and neck squamous cell carcinoma (HNSCC) tissues had coexpression of total and phosphorylated IGF-1R and EGFR at high levels compared with paired adjacent normal tissues. Treatment with cixutumumab (IMC-A12), a fully humanized IgG1 mAb, induced activation of Akt and mTOR, resulting in de novo synthesis of EGFR, Akt1, and survivin proteins and activation of the EGFR pathway in cixutumumab-resistant HNSCC and non–small cell lung cancer (NSCLC) cells. Targeting mTOR and EGFR pathways by treatment with rapamycin and cetuximab (an anti-EGFR mAb), respectively, prevented cixutumumab-induced expression of EGFR, Akt, and survivin and induced synergistic antitumor effects in vitro and in vivo. These data show that resistance to IGF-1R inhibition by mAbs is associated with Akt/mTOR-directed enhanced synthesis of EGFR, Akt1, and survivin. Our findings suggest that Akt/mTOR might be effective targets to overcome the resistance to IGF-1R mAbs in HNSCC and NSCLC. Mol Cancer Ther; 10(12); 2437–48. ©2011 AACR.
Hydrogen Sulfide as Endothelium-Derived Hyperpolarizing Factor Sulfhydrates Potassium Channels
Authors: Mustafa Asif K. , Sikka Gautam , Gazi Sadia K. , Steppan Jochen , Jung Sung M. , Bhunia Anil K. , Barodka Viachaslau M. , Gazi Farah K. , Barrow Roxanne K. , Wang Rui , Amzel L. Mario , Berkowitz Dan E. , Snyder Solomon H.
Published: October 2011

Rationale:

Nitric oxide, the classic endothelium-derived relaxing factor (EDRF), acts through cyclic GMP and calcium without notably affecting membrane potential. A major component of EDRF activity derives from hyperpolarization and is termed endothelium-derived hyperpolarizing factor (EDHF). Hydrogen sulfide (H
2
S) is a prominent EDRF, since mice lacking its biosynthetic enzyme, cystathionine γ-lyase (CSE), display pronounced hypertension with deficient vasorelaxant responses to acetylcholine.

Objective:

The purpose of this study was to determine if H
2
S is a major physiological EDHF.

Methods and Results:

We now show that H
2
S is a major EDHF because in blood vessels of CSE-deleted mice, hyperpolarization is virtually abolished. H
2
S acts by covalently modifying (sulfhydrating) the ATP-sensitive potassium channel, as mutating the site of sulfhydration prevents H
2
S-elicited hyperpolarization. The endothelial intermediate conductance (IK
Ca
) and small conductance (SK
Ca
) potassium channels mediate in part the effects of H
2
S, as selective IK
Ca
and SK
Ca
channel inhibitors, charybdotoxin and apamin, inhibit glibenclamide-insensitive, H
2
S-induced vasorelaxation.

Conclusions:

H
2
S is a major EDHF that causes vascular endothelial and smooth muscle cell hyperpolarization and vasorelaxation by activating the ATP-sensitive, intermediate conductance and small conductance potassium channels through cysteine
S
-sulfhydration. Because EDHF activity is a principal determinant of vasorelaxation in numerous vascular beds, drugs influencing H
2
S biosynthesis offer therapeutic potential.
Epidemiology and Outcomes of Fever Burden Among Patients With Acute Ischemic Stroke
Authors: Phipps Michael S. , Desai Rani A. , Wira Charles , Bravata Dawn M.
Published: October 2011

Background and Purpose—

Although fever following ischemic stroke is common and has been associated with poor patient outcomes, little is known about which aspects of fever (eg, frequency, severity, or duration) are most associated with outcomes.

Methods—

We used data from a retrospective cohort of acute ischemic stroke patients who were admitted to 1 of 5 hospitals (1998–2003). A fever event was defined as a period with a temperature ≥100.0°F (37.8°C). Fever burden was defined as the maximum temperature (T
max
) minus 100.0°F, multiplied by the number of days with a fever. Fever burden (in degree-days) was categorized as low (0.1–2.0), medium (2.1–4.0), or high (≥4.0). Logistic regression was used to evaluate the adjusted association of any fever episode and fever burden with the combined outcome of in-hospital mortality or discharge to hospice.

Results—

Among 1361 stroke patients, 483 patients (35.5%) had ≥1 fever event. Among febrile patients, the median T
max
was 100.9°F (range, 100.0–106.6°F), 87% had ≤2 events and median total fever days was 2. Patients with any fever event had higher combined outcome rates after adjusting for demographics, stroke severity, and clinical characteristics: adjusted odds ratio (aOR), 2.7 (95% CI, 1.6–4.4). Higher fever burden was also associated with the combined outcome: high burden aOR, 6.7 (95% CI, 3.6–12.7); medium burden aOR, 3.9 (95% CI, 1.9–8.2); and low burden aOR, 1.2 (95%CI, 0.6–2.3) versus no fever.

Conclusions—

This study confirms that poststroke fever occurs commonly and demonstrates that patients with high fever burden have a 6-fold increased odds of death or discharge to hospice.
Age and Outcomes After Carotid Stenting and Endarterectomy
Authors: Voeks Jenifer H. , Howard George , Roubin Gary S. , Malas Mahmoud B. , Cohen David J. , Sternbergh W. Charles , Aronow Herbert D. , Eskandari Mark K. , Sheffet Alice J. , Lal Brajesh K. , Meschia James F. , Brott Thomas G. ,   for the CREST Investigators
Published: October 2011

Background and Purpose—

High stroke event rates among carotid artery stenting (CAS)-treated patients in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) lead-in registry generated an a priori hypothesis that age may modify the relative efficacy of CAS versus carotid endarterectomy (CEA). In the primary CREST report, we previously noted significant effect modification by age. Here we extend this investigation by examining the relative efficacy of the components of the primary end point, the treatment-specific impact of age, and contributors to the increasing risk in CAS-treated patients at older ages.

Methods—

Among 2502 CREST patients with high-grade carotid stenosis, proportional hazards models were used to examine the impact of age on the CAS-to-CEA relative efficacy, and the impact of age on risk within CAS-treated and CEA-treated patients.

Results—

Age acted as a treatment effect modifier for the primary end point (
P interaction
=0.02), with the efficacy of CAS and CEA approximately equal at age 70 years. For CAS, risk for the primary end point increased with age (
P
<0.0001) by 1.77-times (95% confidence interval, 1.38–2.28) per 10-year increment; however, there was no evidence of increased risk for CEA-treated patients (
P
=0.27). Stroke events were the primary contributor to the overall effect modification (
P interaction
=0.033), with equal risk at ≈64 years. The treatment-by-age interaction for CAS and CEA was not altered by symptomatic status (
P
=0.96) or by sex (
P
=0.45).

Conclusions—

Outcomes after CAS versus CEA were related to patient age, attributable to increasing risk for stroke after CAS at older ages. Patient age should be an important consideration when choosing between the 2 procedures for treating carotid stenosis.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00004732.
Representativeness of the Get With The Guidelines–Stroke Registry
Authors: Reeves Mathew J. , Fonarow Gregg C. , Smith Eric E. , Pan Wenqin , Olson DaiWai , Hernandez Adrian F. , Peterson Eric D. , Schwamm Lee H.
Published: October 2011

Background and Purpose—

Get With The Guidelines (GWTG)—Stroke is a large quality improvement-based registry of acute stroke; however, its generalizability is unclear. We used fee-for-service Medicare claims to ascertain the representativeness of ischemic stroke admissions in GWTG-Stroke.

Methods—

All 228 815 ischemic stroke admissions aged ≥65 years enrolled in GWTG-Stroke between April 2003 and December 2007 were linked to 926 756 unique fee-for-service Medicare patients with ischemic stroke (primary International Classification of Diseases, 9th Revision discharge code 434 or 436) from the same period. Patient characteristics and in-hospital outcomes were compared between the linked GWTG-Stroke Medicare cohort and the remaining unlinked Medicare cohort. Characteristics of GWTG-Stroke hospitals were compared with non-GWTG-Stroke hospitals.

Results—

A total of 144 344 of the 228,815 GWTG-Stroke admissions (63.1%) were successfully linked to the 926 756 Medicare ischemic stroke beneficiaries, leaving 782 412 unlinked Medicare patients. Differences in patient characteristics, including age, race, gender, and comorbidities, between the linked and unlinked Medicare cohorts were minimal. Length of stay and rate of discharge home were almost identical between the linked and unlinked groups; however, in-hospital mortality was slightly lower in the linked Medicare cohort (6.3%) compared with the unlinked cohort (7.0%). There were large differences in hospital characteristics between GWTG-Stroke and non-GWTG-Stroke hospitals; GWTG-Stroke hospitals tended to be larger, urban, teaching centers.

Conclusions—

Despite substantial differences between GWTG-Stroke and non-GWTG-Stroke hospitals, Medicare beneficiaries with acute ischemic stroke entered in the GWTG-Stroke program were similar to other Medicare beneficiaries. These data suggest that the Medicare-aged GWTG-Stroke ischemic stroke admissions are generally representative of the national fee-for-service Medicare ischemic stroke population.
Influence of Socioeconomic Status on Distance Traveled and Care After Stroke
Authors: Ahuja Christopher , Mamdani Muhammad , Saposnik Gustavo ,   for the Stroke Outcomes Research Canada working group
Published: October 2011

Background and Purpose—

Vital to maintaining an efficient delivery of services is an understanding of patient travel patterns during an acute ischemic stroke. Socioeconomic status may influence access to stroke care, including transportation and admission to different facility types.

Methods—

We analyzed all acute ischemic stroke admissions between 2003 and 2007 through the Discharge Abstract Database, a national database containing patient-level sociodemographic, diagnostic, procedural, and administrative information across Canada. Socioeconomic status was defined in neighborhood quintiles according to Statistics Canada. Distances between patients and facilities were derived from postal codes. A principal diagnosis of ischemic stroke was identified using the International Classification of Diseases (versions 9 and 10). Analysis of variance and regression analyses were performed with adjustment for demographic characteristics.

Results—

Admitted to acute care institutions were 243 410 patients with ischemic stroke. Mean patient age was 72.8 and 49.5% were male; 44.2% traveled beyond their closest center, amounting to an average 7.2 km additional distance traveled. Socioeconomic status quintile had minimal effect on travel patterns, with the lowest socioeconomic status accessing the closest center most frequently (odds ratio, 1.19; 95% confidence interval [CI], 1.13–1.16). Increased utilization of the closest hospital occurred with academic (odds ratio, 6.90; 95% CI, 6.69–7.11) or high-volume (odds ratio, 1.93; 95% CI, 1.88–1.98) facilities. Older patients (β=0.28; 95% CI, 0.27–0.28), expert destination facility (β=0.13; 95% CI, 0.12–0.14), and ambulance use increased travel beyond the closest center.

Conclusions—

Patients tend to choose care facilities based on hospital expertise; investment promoting improved regional facilities may be of greatest benefit to patients. Socioeconomic status has little bearing on travel patterns associated with stroke in Canada. These findings may assist in allocating funding to centers and improving patient care.
Impact of Flow-Dependent Horizontal Diffusion on Resolved Convection in AROME
Authors: Bengtsson Lisa , Tijm Sander , Váňa Filip , Svensson Gunilla
Published: October 2011

Horizontal diffusion in numerical weather prediction models is, in general, applied to reduce numerical noise at the smallest atmospheric scales. In convection-permitting models, with horizontal grid spacing on the order of 1–3 km, horizontal diffusion can improve the model skill of physical parameters such as convective precipitation. For instance, studies using the convection-permitting Applications of Research to Operations at Mesoscale model (AROME) have shown an improvement in forecasts of large precipitation amounts when horizontal diffusion is applied to falling hydrometeors. The nonphysical nature of such a procedure is undesirable, however. Within the current AROME, horizontal diffusion is imposed using linear spectral horizontal diffusion on dynamical model fields. This spectral diffusion is complemented by nonlinear, flow-dependent, horizontal diffusion applied on turbulent kinetic energy, cloud water, cloud ice, rain, snow, and graupel. In this study, nonlinear flow-dependent diffusion is applied to the dynamical model fields rather than diffusing the already predicted falling hydrometeors. In particular, the characteristics of deep convection are investigated. Results indicate that, for the same amount of diffusive damping, the maximum convective updrafts remain strong for both the current and proposed methods of horizontal diffusion. Diffusing the falling hydrometeors is necessary to see a reduction in rain intensity, but a more physically justified solution can be obtained by increasing the amount of damping on the smallest atmospheric scales using the nonlinear, flow-dependent, diffusion scheme. In doing so, a reduction in vertical velocity was found, resulting in a reduction in maximum rain intensity.
Measuring the Impact of Observations on the Predictability of the Kuroshio Extension in a Shallow-Water Model
Authors: Kramer Werner , Dijkstra Henk A. , Pierini Stefano , van Leeuwen Peter Jan
Published: October 2011

In this paper, sequential importance sampling is used to assess the impact of observations on an ensemble prediction for the decadal path transitions of the Kuroshio Extension. This particle-filtering approach gives access to the probability density of the state vector, which allows the predictive power—an entropy-based measure—of the ensemble prediction to be determined. The proposed setup makes use of an ensemble that, at each time, samples the climatological probability distribution. Then, in a postprocessing step, the impact of different sets of observations is measured by the increase in predictive power of the ensemble over the climatological signal during one year. The method is applied in an identical-twin experiment for the Kuroshio Extension using a reduced-gravity shallow-water model. This study investigates the impact of assimilating velocity observations from different locations during the elongated and the contracted meandering states of the Kuroshio Extension. Optimal observation locations correspond to regions with strong potential vorticity gradients. For the elongated state the optimal location is in the first meander of the Kuroshio Extension. During the contracted state it is located south of Japan, where the Kuroshio separates from the coast.
Formation and Photocatalytic Decomposition of a Pellicle on Anatase Surfaces
Authors: Rupp F. , Haupt M. , Eichler M. , Doering C. , Klostermann H. , Scheideler L. , Lachmann S. , Oehr C. , Wendel H.P. , Decker E. , Geis-Gerstorfer J. , von Ohle C.
Published: October 2011

The acquired dental pellicle plays a critical role in the adhesion and detachment of dental plaque bacteria. It has been reported that titanium dioxide biomaterials decompose single-protein films by photocatalysis. However, it is not known whether this can also be achieved with complex structured pellicle films. This in vitro study investigated in real-time the formation and photocatalytic decomposition of human pellicle at anatase-saliva interfaces. Nanostructured polycrystalline anatase layers were deposited on titanium-coated quartz crystals by magnetron-sputtering, serving as a model for titanium implant surfaces. The quartz crystals were used as acoustic sensors in a quartz-crystal microbalance (QCM) system with dissipation. In situ UV irradiation of pellicle-covered anatase caused a statistically significant decrease of the adsorbed salivary mass. In contrast, photocatalytic decomposition of pellicle could not be observed on reference titanium surfaces. Wettability characterization revealed superhydrophilicity of anatase upon UV irradiation, whereas titanium was unaffected. XPS measurements provide further information concerning the decomposition of the salivary films. The results suggest that the photocatalytic activity of polycrystalline anatase-modified biomaterial surfaces is able to decompose complex structured macromolecular pellicle films. Therefore, this study opens the way to surface modifications supporting therapeutic approaches of biofilm removal.
Ramsay-Curve Differential Item Functioning
Authors: Woods Carol M.
Published: October 2011

Differential item functioning (DIF) occurs when an item on a test, questionnaire, or interview has different measurement properties for one group of people versus another, irrespective of true group-mean differences on the constructs being measured. This article is focused on item response theory based likelihood ratio testing for DIF (IRT-LR or IRT-LR-DIF). Historically, the models have been fitted assuming the latent variables for both reference and focal groups are normal, but this is unnecessary. A new variation, called Ramsay-curve DIF (RC-DIF), is introduced here. In RC-DIF, the latent density for both groups is estimated simultaneously with the item parameters. Similar approaches in which the density for only one group is estimated, or the densities are estimated as empirical histograms (EHs), are also studied. Free software is available from the author to test each item individually for DIF with the latent densities estimated as EHs or RCs. A simulation study shows that these methods improve results compared with assuming normality mistakenly, and an empirical example illustrates the procedures.
On the buckling analysis of isotropic, transversely isotropic, and laminated rectangular plates via Reddy plate theory: an exact closed-form procedure
Authors: Hosseini-Hashemi Sh , Atashipour S R , Fadaee M
Published: October 2011

Based on Reddy's third-order shear deformation theory, an exact closed-form solution is proposed to describe linear buckling of transversely isotropic laminated rectangular plates under either mono- or bi-axial compressive in-plane loads. To this end, the coupled governing equations are exactly converted to two sets of uncoupled equations for in-plane and transverse deformations of symmetric laminated plates. The new uncoupled equations are analytically solved by applying both Navier and Lévy-type solution methods. The validity and high accuracy of the current exact solution are evaluated by comparing the present results with their counterparts reported in literature.
Gender, Socioeconomic Status, and Self-Rated Health in a Transitional Middle-Income Setting
Authors: Seubsman Sam-ang , Kelly Matthew James , Yiengprugsawan Vasoontara , Sleigh Adrian C. ,   and the Thai Cohort Study Team
Published: October 2011

Poor self-rated health (SRH) correlates strongly with mortality. In developed countries, women generally report worse SRH than males. Few studies have reported on SRH in developing countries. The authors report on SRH in Thailand, a middle-income developing country.The data were derived from a large nationwide cohort of 87 134 adult Open University students (54% female, median age 29 years). The authors included questions on socioeconomic and demographic factors that could influence SRH. The Thai cohort in this study mirrors patterns found in developed countries, with females reporting more frequent “poor” or “very poor” SRH (odds ratio = 1.35; 95% confidence interval = 1.26-1.44). Cohort males had better SRH than females, but levels were more sensitive to socioeconomic status. Income and education had little influence on SRH for females. Among educated Thai adults, females rate their health to be worse than males, and unlike males, this perception is relatively unaffected by socioeconomic status.
Health Care Financing in Asia
Authors: Kwon Soonman
Published: October 2011

This article examines the major elements of health care financing such as financial risk protection, resource generation, resource pooling, and purchasing and payment; provides key lessons; and discusses the challenges for health care financing systems of Asian countries. With the exception of Japan, Korea, Taiwan, and Thailand, most health care systems of Asia provide very limited financial risk protection. The role of public prepaid schemes such as tax and social health insurance is minimal, and out-of-pocket payment is a major source of financing. The large informal sector is a major challenge to the extension of population coverage in many low-income countries of Asia, which must seek the optimal mix of tax subsidy and health insurance for universal coverage. Implementation of effective payment systems to control the behavior of health care providers is also a key factor in the success of health care financing reform in Asia.
Urban–Rural and Socioeconomic Variations in the Knowledge of STIs and AIDS Among Bangladeshi Adolescents
Authors: Gani M. Showkat , Chowdhury A. Mushtaque R. , Nyström Lennarth
Published: October 2011

This study used data from the Bangladesh Adolescents Survey 2005 to identify socioeconomic and urban–rural determinants of knowledge regarding sexually transmitted infections (STIs) including HIV/AIDS transmission. A cluster sampling of 11 986 adolescents was conducted from April to August 2005. Data were analyzed using SPSS applying principle component analysis, multivariate logistic regression analysis, and prevalence ratios (PRs) with 95% confidence intervals (CIs). Overall knowledge of transmission of STIs was poor (4.5%), showing urban adolescents having twice the knowledge of rural adolescents (PR = 1.9; 95% CI = 1.6-2.2). HIV/AIDS knowledge level was high (68%), with a 40% higher knowledge among urban adolescents (PR = 1.4; 95% CI = 1.3-1.4). Probability of knowledge of STIs and HIV/AIDS transmission was lowest in 12- to 14-year-old uneducated female household workers of the poorest socioeconomic status in rural settings (0.0002 and 0.064, respectively). The urban–rural factor was more important than the socioeconomic factor. Health promotion and education programs can play an important role in improving the sexual reproductive health knowledge situation.
Life course transitions and the future of fandom
Authors: Harrington C. Lee , Bielby Denise D. , Bardo Anthony R.
Published: October 2011

We explore the future of media fandom through integrating insights from gerontology, human development, fan studies, and marketing. Given population aging and the dismantling of the normative 20th-century life course, along with rapid changes in the extent to which our lives are mediated, fandom is undergoing significant modification. We focus on how new findings on emotional maturation over the life course and scholarly identification of self-narrativization as a resource for 21st-century aging suggest ways that fandom may change over time.
‘Here come the cops’: Policing the resistance in rap music
Authors: Nielson Erik
Published: October 2011

When rap music broke into the mainstream in the late 1980s, it was quickly hailed as a vehicle for political resistance against the blatant social and racial inequalities in the United States. However, a closer look at even the most ostensibly rebellious and confrontational songs reveals that the resistive potential within rap music was often undermined, or at least complicated, by the pervasive culture of policing and surveillance from which it emerged. Through close readings of classic tracks by Ice Cube, Goodie Mob and the Geto Boys, this article argues that traditional scholarly formulations of rap-as-resistance need rethinking, and that we must account for the aggressive strategies of social control that have been integral in shaping, and often circumscribing, the kinds of defiance that rap embraces.
Re-examination of the emissivity of diesel flames
Authors: Kamimoto T , Murayama Y
Published: October 2011

In the Hottel and Broughton equation, the spectral emissivity of soot in flames in the visible wavelength range is characterized by an index α = 1.39, which represents the effect of wavelength on extinction (Hottel and Broughton, 1932). In this study, the spectral specific extinction for diesel soot is examined first by focusing on soot layers sampled on a quartz window from the engine cylinder, and α = 1.38 is obtained. To examine the physics governing the value of α = 1.38, a calculation of spectral extinction is performed using the Rayleigh–Debye–Gans (RDG) theory of soot aggregate scattering with an assumption of constant refractive index. The calculated spectral extinction provides α = 1.31 close to α = 1.38, suggesting that scattering, as well as absorption, contributes largely to the spectral extinction of diesel soot. The attenuation of line-of-sight beam intensity due to out-scattering and the augmentation of the beam intensity as a result of scattering of incoming radiation from other regions are investigated using soot aggregate scattering theory. Based on this approach, a new formula of apparent spectral emissivity εa is proposed, allowing a theoretical explanation of the physical meaning of the KL factor defined in the Hottel and Broughton equation, which has remained vague for many years. Finally the two-colour flame temperature and the KL factor in a production engine are calculated using the new emissivity formula and are compared with those obtained using the conventional emissivity formula. The result shows that the two-colour method using the conventional emissivity formula remains quite useful, and provides values of temperature and KL factor within 1–2 per cent of those obtained with the new emissivity formula.
Low-Dose (1 μg/kg) Clonidine Premedication and Hypotension After Carotid Artery Surgery
Authors: Pandazi Ageliki , Karamanis Periandros , Sidiropoulou Tatiana , Matsota Paraskevi , Papasideris Christos , Niokou Dimitra , Kostopanagiotou Georgia
Published: October 2011

We investigated the role of low-dose clonidine intravenous (IV) premedication in arterial pressure variation during and after carotid endarterectomy (CEA). A total of 84 patients, American Society of Anesthesiologists (ASA) II-III, scheduled for elective CEA under general anesthesia participated in this study. The patients were divided into 2 groups: group P (n = 42) and group C (n = 42) and received N/S 0.9% (placebo) or clonidine 1 μg/kg IV, respectively, 15 minutes before induction of anesthesia. Recovery times, number of patients needed to be treated for circulatory events (hypertension, hypotension, and bradycardia), number of circulatory events per patient, and consumption of vasoactive drugs (nitroglycerine, phenylphrine, and atropine) intraoperatively and the first 6 hours postoperatively were recorded. Significantly less hypertensive episodes were observed intraoperatively, but more hypotensive episodes were observed postoperatively in patients receiving clonidine. Intravenous premedication with low-dose clonidine (1 μg/kg) seems to be effective in preventing hypertensive episodes during CEA under general anesthesia but seems to increase the incidence of hypotension postoperatively.
On nonlinear stability in various random normed spaces
Authors: Rassias John Michael , Saadati Reza , Sadeghi Ghadir , Vahidi J
Published: October 2011

In this article, we prove the nonlinear stability of the quartic functional equation

1
6
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+
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)

+
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(

4
x
-
y

)

=

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0
6

9
f

x
+

y

3

+
f

(

x
+
2
y

)

(1)

+
1
3
6
f

(

x
-
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)

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1
3
9
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f

(

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+
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)

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f

(

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(2)

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in the setting of random normed spaces Furthermore, the interdisciplinary relation among the theory of random spaces, the theory of non-Archimedean space, the theory of fixed point theory, the theory of intuitionistic spaces and the theory of functional equations are also presented in the article.
The rgg
0182
gene encodes a transcriptional regulator required for the full Streptococcus thermophilusLMG18311 thermal adaptation
Authors: Henry Romain , Bruneau Emmanuelle , Gardan Rozenn , Bertin Stéphane , Fleuchot Betty , Decaris Bernard , Leblond-Bourget Nathalie
Published: October 2011

Background

Streptococcus thermophilus is an important starter strain for the production of yogurt and cheeses. The analysis of sequenced genomes of four strains of S. thermophilus indicates that they contain several genes of the rgg familly potentially encoding transcriptional regulators. Some of the Rgg proteins are known to be involved in bacterial stress adaptation.

Results

In this study, we demonstrated that Streptococcus thermophilus thermal stress adaptation required the rgg

0182
gene which transcription depends on the culture medium and the growth temperature. This gene encoded a protein showing similarity with members of the Rgg family transcriptional regulator. Our data confirmed that Rgg0182 is a transcriptional regulator controlling the expression of its neighboring genes as well as chaperones and proteases encoding genes. Therefore, analysis of a Δrgg

0182
mutant revealed that this protein played a role in the heat shock adaptation of Streptococcus thermophilus LMG18311.

Conclusions

These data showed the importance of the Rgg0182 transcriptional regulator on the survival of S. thermophilus during dairy processes and more specifically during changes in temperature.
Analysis of changes in the association of income and the utilization of curative health services in Mexico between 2000 and 2006
Authors: Danese-dlSantos Laura G , Sosa-Rubí Sandra G , Valencia-Mendoza Atanacio
Published: October 2011

Background

A common characteristic of health systems in most developing countries is unequal access to health services. As a result, members of the poorest population groups often do not receive formal attention for health services, because they cannot afford it. In 2001 in Mexico, to address income-related differences in the use of health services, the government launched a major healthcare reform, which includes a health insurance program called Seguro Popular, aimed at improving healthcare access among poor, uninsured residents. This paper analyzes the before and after changes in the demand for curative ambulatory health services focusing on the association of income-related characteristics and the utilization of formal healthcare providers vs. no healthcare service utilization.

Methods

By using two nationally representative health surveys (ENSA-2000 and ENSANUT-2006), we modeled an individual's decision when experiencing an illness to use services provided by the (1) Ministry of Health (MoH), (2) social security, (3) private entities, or (4) to not use formal services (no healthcare service utilization).

Results

Poorer individuals were more likely in 2006 than in 2000 to respond to an illness by using formal healthcare providers. Trends in provider selection differed, however. The probability of using public services from the MoH increased among the poorest population, while the findings indicated an increase in utilization of private health services among members of low- and middle-income groups. No significant change was seen among formal workers -covered by social security services-, regardless of socioeconomic status.

Conclusions

Overall, for 2006 the Mexican population appears less differentiated in using healthcare across economic groups than in 2000. This may be related, in part, to the implementation of Seguro Popular, which seems to be stimulating healthcare demand among the poorest and previously uninsured segment of the population. Still, public health authorities need to address the remaining income-related healthcare utilization differences, the differences in quality between public and private health services, and the general perception that MoH facilities offer inferior services.
Tannin extracts from immature fruits of Terminalia chebula Fructus Retz. promote cutaneous wound healing in rats
Authors: Li Kun , Diao Yunpeng , Zhang Houli , Wang Shouyu , Zhang Zhen , Yu Bo , Huang Shanshan , Yang Hong
Published: October 2011

Background

Tannins extracted from immature fruits of Terminalia chebula Fructus Retz. are considered as effective components promoting the process of wound healing. The objective of this study is to explore the optimal extraction and purification technology (OEPT) of tannins, while studying the use of this drug in the treatment of a cutaneous wound of rat as well as its antibacterial effects.

Methods

The content of tannin extracts was measured by the casein method, and antibacterial ability was studied by the micro-dilution method in vitro. In wound healing experiment, animals in group I, II and II were treated with vaseline ointment, tannin extracts (tannin content: 81%) and erythromycin ointment, respectively (5 mg of ointment were applied on each wound). To evaluate the process of wound healing, selected pharmacological and biochemical parameters were applied.

Results

After optimal extraction and purification, content of tannin extracts was increased to 81%. Tannin extracts showed the inhibition of Staphylococcus aureus and Klebsiella Pneumonia in vitro. After excision of wounds, on days 7 and 10, the percent of wound contraction of group was higher than that of group . After being hurt with wounds, on days 3, 7, and 10, the wound healing quality of group was found to be better than that of group in terms of granulation formation and collagen organization. After wound creation, on day 3, the vascular endothelial growth factor expression of group was higher than that of group .

Conclusion

The results suggest that tannin extracts from dried immature fruits of Terminalia chebula Fructus Retz. can promote cutaneous wound healing in rats, probably resulting from a powerful anti-bacterial and angiogenic activity of the extracts.