bluuebunny/crossref_metadata_2025 huggingface dataset:
Initial Characterization of Hydrogen Sulfide Effects in Female Sexual Function
Authors: Srilatha Balasubramanian , Hu Lingxu , Adaikan Ganesan P. , Moore Philip K.
Published: April 2009

Introduction

In our male animal models, hydrogen sulfide (H2S) displayed significant vasodilatory and smooth muscle relaxant effects suggestive of an endogenous physiological role in erectile process.

Aim

In this first exploratory study, we aimed to identify the existence and mechanism of H2S pathway in female sexual physiology.

Methods

Vaginal and clitoral cavernosal smooth muscle strips from New Zealand white rabbits (N = 12) were exposed to stable H2S donor, sodium hydrosulfide hydrate (NaHS.xH2O, 100 µM–1.6 mM), in isometric tension studies. The NaHS responses were repeated after incubations with (i) Nω-nitro-L-arginine (50 µM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) (10 µM) or cis-N-[2-phenylcyclopentyl]-azacyclotridec-1-en-2-amine (MDL 12,330A) (10 µM); and (ii) potassium chloride medium (high K+ 60 mM/low K+ 10 mM), tetraethylammonium (10 mM) or glibenclamide (100 µM). Relaxant effect of NaHS was also compared with those of nitroglycerine (0.18–78.2 µM) and sildenafil (0.084–25.3 µM). Additionally, samples (N = 16) were collected for estimations of plasma and tissue H2S and expression levels of cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS) proteins.

Main Outcome Measures

In vitro evidences for H2S formation and its physiopharmacological effects.

Results

NaHS produced significant concentration-dependent relaxation of vaginal and cavernosal smooth muscles with inhibitions by combination of ODQ and MDL 12,330A (26.4%), Nω-nitro-L-arginine (22.2%), high K+ (15.1%) or glibenclamide (10.1%). Based on molar potency, NaHS was 18.3 and 6.3 times weaker than nitroglycerine and sildenafil, respectively. Quantitative assays indicated that plasma H2S level was 16.5 ± 2.58 µM, and H2S was synthesized in the clitoral and vaginal smooth muscles (1.8 and 3.9 nmol/mg soluble protein compared with 26.5 nmol/mg in the liver: positive control). Similarly, western blotting identified the protein expression bands of CSE (44.5 kDa) and CBS (63 kDa) in these genital tissue samples.

Conclusion

These pilot studies clearly indicate the smooth muscle relaxant effect of H2S in female genital tract, mediating through cyclic adenosine 3′:5′-monophosphate, nitric oxide-cyclic guanosine monophosphate and K+ATP channels. Taken together with biochemical and molecular evidences for endogenous formation, H2S pathway could be a contributing factor in female sexual responses.
Approved Hormonal Treatments for HSDD: An Unmet Medical Need
Authors: Snabes Michael C. , Simes Stephen M.
Published: April 2009

Introduction

Despite a high prevalence of hypoactive sexual desire disorder (HSDD), no medical treatment is available in the United States for this condition.

Aim

To identify the current prescribing pattern of off-label testosterone use in treating HSDD.

Main Outcome Measures

Quantitation of Intercontinental Marketing Services (IMS) prescription data to identify testosterone prescriptions written for women and a summary of response to queries to opinion leaders and practicing physicians.

Methods

Interviews and an opinion poll of gynecologists and family medicine physicians on current medical treatment of HSDD.

Results

The IMS prescription review showed that: two million testosterone prescriptions were written for women in 2006 and 2007—many physicians have prescribed compounded testosterone. Based on a summary of the physicians’ survey: on average, patients of all ages, but particularly menopausal women, have at least moderate awareness of HSDD. More than 80% of physicians believe there is a need or great need for a Food and Drug Administration- (FDA) approved HSDD treatment. Ninety percent of physicians surveyed would prescribe an approved HSDD product over currently prescribed therapy.

Conclusions

In the context of increased regulatory scrutiny, increasing off-label use of testosterone, formulation and dosing issues, increased patient awareness of FSD and HSDD, and overall favorable physician sentiment, the completion of the LibiGel® clinical development program and an FDA approval will meet the demand for the first safe and effective FDA-approved treatment of HSDD in postmenopausal women.
AKINβ1 is Involved in the Regulation of Nitrogen Metabolism and Sugar Signaling in Arabidopsis
Authors: Li Xiao‐Fang , Li Yu‐Ju , An Ying‐Hui , Xiong Li‐Jun , Shao Xing‐Hua , Wang Yang , Sun Yue
Published: April 2009

Sucrose non‐fermenting‐1‐related protein kinase 1 (SnRK1) has been located at the heart of the control of metabolism and development in plants. The active SnRK1 form is usually a heterotrimeric complex. Subcellular localization and specific target of the SnRK1 kinase are regulated by specific beta subunits. In Arabidopsis, there are at least seven genes encoding beta subunits, of which the regulatory functions are not yet clear. Here, we tried to study the function of one beta subunit, AKINβ1. It showed that AKINβ1 expression was dramatically induced by ammonia nitrate but not potassium nitrate, and the investigation of AKINβ1 transgenic Arabidopsis and T‐DNA insertion lines showed that AKINβ1 negatively regulated the activity of nitrate ruductase and was positively involved in sugar repression in early seedling development. Meanwhile AKINβ1 expression was reduced upon sugar treatment (including mannitol) and did not affect the activity of sucrose phosphate synthase. The results indicate that AKINβ1 is involved in the regulation of nitrogen metabolism and sugar signaling.
Revisiting the origin of the high metallicities of sub-damped Lyman-alpha systems
Authors: Dessauges-Zavadsky Miroslava , Ellison Sara L. , Murphy Michael T.
Published: April 2009

Sub-damped Lyman-alpha systems (sub-DLAs) have previously been found to exhibit a steeper metallicity evolution than the classical damped Lyman-alpha systems (DLAs), evolving to close to solar metallicity by z∼ 1. From new high-resolution spectra of 17 sub-DLAs, we have increased the number of measurements of [Fe/H] at z < 1.7 by 25 per cent and compiled the most complete literature sample of sub-DLA and DLA abundances to date. We find that sub-DLAs are indeed significantly more metal-rich than DLAs, but only at z < 1.7; the metallicity distributions of sub-DLAs and DLAs at z > 1.7 are statistically consistent. We also present the first evidence that sub-DLAs follow a velocity width–metallicity correlation over the same velocity range as DLAs, but the relation is offset to higher metallicities than the DLA relation. On the basis of these results, we revisit the previous explanation that the systematically higher metallicities observed in sub-DLAs are indicative of higher host galaxy masses. We discuss the various problems that this interpretation encounters and conclude that in general sub-DLAs are not uniquely synonymous with massive galaxies. We rule out physically related sources of bias (dust, environment, ionization effects) and examine systematics associated with the selection and analysis of low-redshift sub-DLAs. We propose that the high metallicities of sub-DLAs at z < 1.7 that drives an apparently steep evolution may be due to the selection of most low-redshift sub-DLAs based on their high Mgii equivalent widths.
Case–control study for the identification of virological factors associated with fulminant hepatitis B
Authors: Kusakabe Atsunori , Tanaka Yasuhito , Mochida Satoshi , Nakayama Nobuaki , Inoue Kazuaki , Sata Michio , Isoda Norio , Kang Jong‐Hon , Sumino Yasukiyo , Yatsuhashi Hiroshi , Takikawa Yasuhiro , Kaneko Shuichi , Yamada Gotaro , Karino Yoshiyasu , Tanaka Eiji , Kato Junji , Sakaida Isao , Izumi Namiki , Sugauchi Fuminaka , Nojiri Shunsuke , Joh Takashi , Miyakawa Yuzo , Mizokami Masashi
Published: April 2009

Background:  Host and viral factors can promote the development of fulminant hepatitis B (FHB), but there have been no case–control studies for figuring out virological parameters that can distinguish FHB.

Methods:  In a case–control study, virological factors associated with the development of FHB were sought in 50 patients with FH developed by transient hepatitis B virus (HBV) infection (FH‐T) and 50 with acute self‐limited hepatitis B (AHB) who were matched for sex and age. In addition, 12 patients with FH developed by acute exacerbation (AE) of asymptomatic HBV carrier (ASC) (FH‐C) were also compared with 12 patients without FH by AE of chronic hepatitis B (AE‐C).

Results:  Higher HBV DNA levels, subgenotype B1/Bj, A1762T/G1764A, G1896A, G1899A and A2339G mutation were significantly more frequent (P < 0.05), while hepatitis B e‐antigen was less frequent in the FH‐T patients than AHB. In multivariate analysis, G1896A mutation (odds ratio [OR], 13.53; 95% confidence interval [CI], 2.75–66.64), serum HBV DNA more than 5.23 log copies/mL (OR, 5.14; 95% CI, 1.10–24.15) and total bilirubin more than 10.35 mg/mL (OR, 7.81; 95% CI, 1.77–34.51) were independently associated with a fulminant outcome by transient HBV infection. On the other hand, in comparison with the patients between FH‐C and AE‐C groups, there was no significant difference of virological factors associated with the development of FHB.

Conclusion:  A number of virological factors have been defined that may distinguish FH‐T from AHB in a case–control study. The pathogenic mechanism of FHB between transient HBV infection and AE of ASC would be different.
A Method to Improve Platform Leveraging in a Market Segmentation Grid for an Existing Product Line
Authors: Farrell Ronald S. , Simpson Timothy W.
Published: April 2009

This paper describes a method for improving commonality in a highly customized low volume product line whose members were originally developed one at a time to meet specific customer requirements. Rather than focusing on redesign of the entire product line, which can often be cost prohibitive, the method is part of a strategy to redesign a limited set of component parts that have the highest potential for cost savings. The method involves a four-step methodology: (1) determine an optimal component solution for each member artifact of an existing market segment grid, (2) test the feasibility of using each optimal component as a platform for the other artifacts, (3) formulate an optimization problem around the feasibility statistics whose solution is a product platform portfolio, and (4) solve the optimization problem for the platform portfolio that can span the existing market segment grid most cost effectively. The proposed method is applied to an example involving the redesign of actuator mounting yokes for an existing set of valves that are used in nuclear power plants. The methodology shows promise for determining a product platform mix that maximizes cost effectiveness yet meets performance requirements.
Design for Manufacturing of 3D Heterogeneous Objects With Processing Time Consideration
Authors: Hu Yuna , Blouin Vincent Y. , Fadel Georges M.
Published: April 2009

Rapid prototyping (RP) technology, such as laser engineering net shaping, can be used to fabricate heterogeneous objects with various levels of gradient variations in material composition. These objects are engineered to achieve a potentially enhanced functional performance. Past research on the design of such objects has focused on representation, modeling, and desired functional performance. However, the inherent constraints in RP processes, such as system capability and processing dwell time, lead to heterogeneous objects that may not meet the designer’s original intent. To overcome this situation, the research presented in this paper focuses on the identification and implementation of manufacturing concerns into the design process. Previous work on a 2D disk brake rotor design has shown that processing dwell time is one of the critical factors that affect manufacturability. This paper focuses on incorporating the processing time into the optimization design for manufacturing of 3D heterogeneous objects. A node-based finite element modeling technique is used for the representation and analysis. The multicriteria design problem corresponds to finding the nodal material compositions with minimized structural weight, maximized structural stiffness, and minimized extra processing time used to deposit the multimaterial subjected to stress constraints. The optimizer used in this research is a self-adaptive, real-valued evolutionary strategy, which is well suited for this type of multimodal problem. A 3D I-beam made of two materials, aluminum for lightweight and steel for better strength characteristics, is used to illustrate the trade-off between manufacturability and functionality.
The Synthesis of Dyads With One Prismatic Joint
Authors: Chen Chao , Bai Shaoping , Angeles Jorge
Published: April 2009

The classic Burmester problem aims at finding the geometric parameters of a planar four-bar linkage for a prescribed set of finitely separated poses. The synthesis related to the Burmester problem deals with revolute-revolute (RR), prismatic-revolute (PR), and revolute-prismatic (RP) dyads. A PR dyad is a special case of the RR dyad, namely, a dyad of this kind with its fixed joint center at infinity; a similar interpretation applies to the RP dyad. The special nature of dyads with one P joint warrants a special treatment, outside of the general methods of four-bar linkage synthesis, which target mainly RR dyads. In proposing robust computational means to synthesize PR and RP dyads, we adopt an invariant formulation, which, additionally, sheds light on the underlying geometry.
The Influence of Large-Scale, High-Intensity Turbulence on Vane Aerodynamic Losses, Wake Growth, and the Exit Turbulence Parameters
Authors: Ames F. E. , Plesniak M. W.
Published: April 2009

An experimental research program was undertaken to examine the influence of large-scale high-intensity turbulence on vane exit losses, wake growth, and exit turbulence characteristics. The experiment was conducted in a four-vane linear cascade at an exit Reynolds number of 800,000 based on chord length and an exit Mach number of 0.27. Exit measurements were made for four inlet turbulence conditions including a low-turbulence case (Tu ≈ 1 percent), a grid-generated turbulence case (Tu ≈ 7.5. percent) and two levels of large-scale turbulence generated with a mock combustor (Tu ≈ 12 and 8 percent). Exit total pressure surveys were taken at two locations to quantify total pressure losses. The suction surface boundary layer was also traversed to determine losses due to boundary layer growth. Losses occurred in the core of the flow for the elevated turbulence cases. The elevated free-stream turbulence was found to have a significant effect on wake growth. Generally, the wakes subjected to elevated free-stream turbulence were broader and had smaller peak velocity deficits. Reynolds stress profiles exhibited asymmetry in peak amplitudes about the wake centerline, which are attributable to differences in the evolution of the boundary layers on the pressure and suction surfaces of the vanes. The overall level of turbulence and dissipation inside the wakes and in the free stream was determined to document the rotor inlet boundary conditions. This is useful information for assessing rotor heat transfer and aerodynamics. Eddy diffusivities and mixing lengths were estimated using X-wire measurements of turbulent shear stress. The free-stream turbulence was found to strongly affect eddy diffusivities, and thus wake mixing. At the last measuring position, the average eddy diffusivity in the wake of the high-turbulence close combustor configuration (Tu ≈ 12) was three times that of the low turbulence wake.
Unsteady Flow Field Due to Nozzle Wake Interaction With the Rotor in an Axial Flow Turbine: Part I—Rotor Passage Flow Field
Authors: Zaccaria M. A. , Lakshminarayana B.
Published: April 2009

The flow field in turbine rotor passages is complex with unsteadiness caused by the aerodynamic interaction of the nozzle and rotor flow fields. The two-dimensional steady and unsteady flow field at midspan in an axial flow turbine rotor has been investigated experimentally using an LDV with emphasis on the interaction of the nozzle wake with the rotor flow field. The flow field in the rotor passage is presented in Part I. while the flow field downstream of the rotor is presented in Part II. Measurements were acquired at 37 axial locations from just upstream of the rotor to one chord downstream of the rotor. The time-averaged flow field and the unsteadiness caused by the wake have been captured. As the nozzle wake travels through the rotor flow field, the nozzle wake becomes distorted with the region of the nozzle wake near the rotor suction surface moving faster than the region near the rotor pressure surface, resulting in a highly distorted wake. The wake is found to be spread out along the rotor pressure surface, as it convects downstream of midchord. The magnitude of the nozzle wake velocity defect grows until close to midchord, after which it decreases. High values of unresolved unsteadiness were observed at the rotor leading edge. This is due to the large flow gradients near the leading edge and the interaction of the nozzle wake with the rotor leading edge. High values of unresolved unsteadiness were also observed near the rotor pressure surface. This increase in unresolved unsteadiness is caused by the interaction of the nozzle wake with the flow near the rotor pressure surface.
Boundary Layer Development in Axial Compressors and Turbines: Part 3 of 4— LP Turbines
Authors: Halstead D. E. , Wisler D. C. , Okiishi T. H. , Walker G. J. , Hodson H. P. , Shin H.-W.
Published: April 2009

This is Part Three of a four-part paper. It begins with Section 11.0 and continues to describe the comprehensive experiments and computational analyses that have led to a detailed picture of boundary layer development on airfoil surfaces in multistage turbomachinery. In this part, we present the experimental evidence that we used to construct the composite picture for LP turbines that was given in the discussion in Section 5.0 of Part 1. We present and interpret the data from the surface hot-film gages and the boundary layer surveys for the baseline operating condition. We then show how this picture changes with variations in Reynolds number, airfoil loading, and nozzle–nozzle clocking.
Measurement of Gust Response on a Turbine Cascade
Authors: Kurkov A. P. , Lucci B. L.
Published: April 2009

The paper presents benchmark experimental data on a gust response of an annular turbine cascade. The experiment was particularly designed to provide data for comparison with the results of a typical linearized gust-response analysis. Reduced frequency, Mach number, and incidence were varied independently. Except for the lowest reduced frequency, the gust velocity distribution was nearly sinusoidal. For the high-inlet-velocity series of tests, the cascade was near choking. The mean flow was documented by measuring blade surface pressures and the cascade exit flow. High-response pressure transducers were used to measure the unsteady pressure distribution. Inlet-velocity components and turbulence parameters were measured using hot wire. In addition to the synchronous time-averaged pressure spectra, typical power spectra are included for several representative conditions.
Free Vortex Theory for Efficiency Calculations From Annular Cascade Data
Authors: Main A. J. , Oldfield M. L. G. , Lock G. D. , Jones T. V.
Published: April 2009

This paper describes a new three-dimensional theory to calculate the efficiency or loss of nozzle guide vane annular cascades from experimental area traverse measurements of the compressible downstream flow. To calculate such an efficiency, it is necessary to mix out the measured flow computationally to either a uniform state or one that is a function of radius only. When this is done by conserving momentum, mass, and energy flow, there is a remaining degree of freedom in that the radial distribution of circumferential velocity can be chosen. This extra freedom does not arise in two-dimensional cascades. The new method mixes the flow out to a free (i.e., irrotational) vortex. This is preferred to existing methods in that it gives a physically realistic flow and also provides a unique, lossless, isentropic reference flow. The annular cascade efficiency is then uniquely defined as the ratio of the mixed-out experimental kinetic energy flux to the ideal isentropic kinetic energy flux at the same mean radius static pressure. The mathematical derivation of this method is presented. This new theory has been used to process data obtained from a large, transonic, annular cascade in a blowdown tunnel. A four-hole pyramid probe, mounted on a computer-controlled traverse, has been used to map the passage flowfield downstream of the nozzle guide vanes. Losses calculated by the new method are compared with those calculated from the same data using earlier analysis methods.
Simulation of Heat Transfer From Flow With High Free-Stream Turbulence to Turbine Blades
Authors: Fridman E.
Published: April 2009

The present investigation is devoted to one of the most difficult problems in the gas turbine industry: predicting the heat transfer to turbine blades. It is known that one of the important factors that affects heat transfer coefficients is a significant level of turbulence in the flow that surrounds a turbine blade. The influence of free-stream turbulence on heat transfer coefficients for a flat plate boundary layer with zero pressure gradient or in the vicinity of the stagnation point of a circular cylinder is investigated numerically. An algebraic relaxation-length model of turbulence is applied in order to simulate real situations in flows with a high level of free-stream turbulence. The results, temperature and velocity profiles, and heat transfer and drag coefficients, are compared with available experimental data. The proposed method is recommended for practical calculations of heat transfer coefficients on turbine blades.
Effect of Periodic Wake Passing on Film Effectiveness of Discrete Cooling Holes Around the Leading Edge of a Blunt Body
Authors: Funazaki K. , Yokota M. , Yamawaki S.
Published: April 2009

Detailed studies are conducted on film effectiveness of discrete cooling holes around the leading edge of a blunt body that is subjected to periodically incoming wakes as well as free-stream turbulence with various levels of intensity. The cooling holes have a configuration similar to that of typical turbine blades except for the spanwise inclination angle. Secondary air is heated so that the temperature difference between the mainstream and secondary air is about 20 K. In this case, the air density ratio of the mainstream and secondary air becomes less than unity, therefore the flow condition encountered in an actual aero-engine cannot be simulated in terms of the density ratio. A spoke-wheel type wake generator is used in this study. In addition, three types of turbulence grids are used to elevate the free-stream turbulence intensity. We adopt three blowing ratios of the secondary air to the mainstream. For each of the blowing ratios, wall temperatures around the surface of the test model are measured by thermocouples situated inside the model. The temperature is visualized using liquid crystals in order to obtain qualitative information of film effectiveness distribution.
Heat Transfer and Film Cooling Effectiveness in a Linear Airfoil Cascade
Authors: Abuaf N. , Bunker R. , Lee C. P.
Published: April 2009

A warm (315°C) wind tunnel test facility equipped with a linear cascade of film cooled vane airfoils was used in the simultaneous determination of the local gas side heat transfer coefficients and the adiabatic film cooling effectiveness. The test rig can be operated in either a steady-state or a transient mode. The steady-state operation provides adiabatic film cooling effectiveness values while the transient mode generates data for the determination of the local heat transfer coefficients from the temperature–time variations and of the film effectiveness from the steady wall temperatures within the same aerothermal environment. The linear cascade consists of five airfoils. The 14 percent cascade inlet free-stream turbulence intensity is generated by a perforated plate, positioned upstream of the airfoil leading edge. For the first transient tests, five cylinders having roughly the same blockage as the initial 20 percent axial chord of the airfoils were used. The cylinder stagnation point heat transfer coefficients compare well with values calculated from correlations. Static pressure distributions measured over an instrumented airfoil agree with inviscid predictions. Heat transfer coefficients and adiabatic film cooling effectiveness results were obtained with a smooth airfoil having three separate film injection locations, two along the suction side, and the third one covering the leading edge showerhead region. Near the film injection locations, the heat transfer coefficients increase with the blowing film. At the termination of the film cooled airfoil tests, the film holes were plugged and heat transfer tests were conducted with non-film cooled airfoils. These results agree with boundary layer code predictions.
Total-Coverage Discrete Hole Wall Cooling
Authors: Cho H. H. , Goldstein R. J.
Published: April 2009

The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length-to-diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 0 to 3 hole diameters, and for Reynolds numbers of 60 to 13,700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two in-line layers, the transfer coefficient affected by the gap spacing is approximately 100 percent higher on the windward surface of the second wall and is about 20 percent lower on the inside hole surface than that with a single layer. The transfer coefficient on the leeward surface is not affected by upstream flow conditions due probably to strong recirculation in the wake flow.
Effect of Velocity and Temperature Distribution at the Hole Exit on Film Cooling of Turbine Blades
Authors: Garg V. K. , Gaugler R. E.
Published: April 2009

An existing three-dimensional Navier–Stokes code (Arnone et al., 1991), modified to include film cooling considerations (Garg and Gaugler, 1994), has been used to study the effect of coolant velocity and temperature distribution at the hole exit on the heat transfer coefficient on three film-cooled turbine blades, namely, the C3X vane, the VKI rotor, and the ACE rotor. Results are also compared with the experimental data for all the blades. Moreover, Mayle’s transition criterion (1991), Forest’s model for augmentation of leading edge heat transfer due to free-stream turbulence (1977), and Crawford’s model for augmentation of eddy viscosity due to film cooling (Crawford et al., 1980) are used. Use of Mayle’s and Forest’s models is relevant only for the ACE rotor due to the absence of showerhead cooling on this rotor. It is found that, in some cases, the effect of distribution of coolant velocity and temperature at the hole exit can be as much as 60 percent on the heat transfer coefficient at the blade suction surface, and 50 percent at the pressure surface. Also, different effects are observed on the pressure and suction surface depending upon the blade as well as upon the hole shape, conical or cylindrical.
Effects of Free-Stream Turbulence on the Instantaneous Heat Transfer in a Wall Jet Flow
Authors: Yavuzkurt S.
Published: April 2009

This is a preliminary study in order to understand how free-stream turbulence increases heat transfer. Effects of free-stream turbulence on instantaneous heat transfer were investigated in a wall jet flow. Heat transfer traces obtained by a hot-film probe flush-mounted with the surface showed an intermittent structure with definite peaks at certain time intervals. The number of peaks per unit time increased with increasing turbulence intensity. A wall jet test rig was designed and built. The initial thickness and the velocity of the wall jet were 10 cm and 24.4 m/s, respectively. The hot-film probe, which was flush with the surfaces, was positioned at 10 cm intervals on the surface in the flow direction. The profiles of mean velocity and axial component of the Reynolds stress were measured with a horizontal hot-wire probe. Space correlation coefficients for u′ and q′ were obtained in the vertical direction to the wall. This paper concentrates on the effects of turbulence level on instantaneous heat transfer at the wall. It is speculated that the intermittent structures of the heat transfer traces are related to burst phenomena and increase in heat transfer is due to increased ejections (bursts) at the wall with increasing turbulence levels.
Turbulent Flow Heat Transfer and Friction in a Rectangular Channel With Varying Numbers of Ribbed Walls
Authors: Chandra P. R. , Niland M. E. , Han J. C.
Published: April 2009

An experimental study of wall heat transfer and friction characteristics of a fully developed turbulent air flow in a rectangular channel with transverse ribs on one, two, and four walls is reported. Tests were performed for Reynolds numbers ranging from 10,000 to 80,000. The pitch-to-rib height ratio, P/e, was kept at 8 and rib height-to-channel hydraulic diameter ratio, e/Dh, was kept at 0.0625. The channel length-to-hydraulic diameter ratio, L/Dh, was 15. The heat transfer coefficient and friction factor values were enhanced with the increase in the number of ribbed walls. The friction roughness function, R(e+), was almost constant over the entire range of tests performed and was within comparable limits of the previously published data. The heat transfer roughness function, G(e+), decreased with additional ribbed walls and compared well with previous work in this area. Friction data obtained experimentally for the case with four ribbed walls compared well with the values predicted by the assumed theoretical relationship used in the present study and past publications. Results of this investigation could be used in various applications of internal channel turbulent flows involving different numbers of roughened walls.
An Experimental Investigation of the Rib Surface-Averaged Heat Transfer Coefficient in a Rib-Roughened Square Passage
Authors: Taslim M. E. , Wadsworth C. M.
Published: April 2009

Turbine blade cooling, a common practice in modern aircraft engines, is accomplished, among other methods, by passing the cooling air through an often serpentine passage in the core of the blade. Furthermore, to enhance the heat transfer coefficient, these passages are roughened with rib-shaped turbulence promoters (turbulators). Considerable data are available on the heat transfer coefficient on the passage surface between the ribs. However, the heat transfer coefficients on the surface of the ribs themselves have not been investigated to the same extent. In small aircraft engines with small cooling passages and relatively large ribs, the rib surfaces comprise a large portion of the passage heat transfer area. Therefore, an accurate account of the heat transfer coefficient on the rib surfaces is critical in the overall design of the blade cooling system. The objective of this experimental investigation was to conduct a series of 13 tests to measure the rib surface-averaged heat transfer coefficient, hrib, in a square duct roughened with staggered 90 deg ribs. To investigate the effects that blockage ratio, e/Dh and pitch-to-height ratio, S/e, have on hrib and passage friction factor, three rib geometries corresponding to blockage ratios of 0.133, 0.167, and 0.25 were tested for pitch-to-height ratios of 5, 7, 8.5, and 10. Comparisons were made between the rib average heat transfer coefficient and that on the wall surface between two ribs, hfloor, reported previously. Heat transfer coefficients of the upstream-most rib and that of a typical rib located in the middle of the rib-roughened region of the passage wall were also compared. It is concluded that: 1 The rib average heat transfer coefficient is much higher than that for the area between the ribs; 2 similar to the heat transfer coefficient on the surface between the ribs, the average rib heat transfer coefficient increases with the blockage ratio; 3 a pitch-to-height ratios of 8.5 consistently produced the highest rib average heat transfer coefficients amongst all tested; 4 under otherwise identical conditions, ribs in upstream-most position produced lower heat transfer coefficients than the midchannel positions, 5 the upstream-most rib average heat transfer coefficients decreased with the blockage ratio; and 6 thermal performance decreased with increased blockage ratio. While a pitch-to-height ratio of 8.5 and 10 had the highest thermal performance for the smallest rib geometry, thermal performance of high blockage ribs did not change significantly with the pitch-to-height ratio.
Entropic Evidence for Linguistic Structure in the Indus Script
Authors: Rao Rajesh P. N. , Yadav Nisha , Vahia Mayank N. , Joglekar Hrishikesh , Adhikari R. , Mahadevan Iravatham
Published: April 2009

Analysis of the pattern of symbols confirms the linguistic role of ancient signs.
Magnetic Field Sensing Beyond the Standard Quantum Limit Using 10-Spin NOON States
Authors: Jones Jonathan A. , Karlen Steven D. , Fitzsimons Joseph , Ardavan Arzhang , Benjamin Simon C. , Briggs G. Andrew D. , Morton John J. L.
Published: April 2009

Quantum-Enhanced Measurement

The single electron spin in a molecule, atom, or quantum dot precesses in a magnetic field and so can be used as a magnetic field sensor. As the number of spins in a sensor increases, so too does the sensitivity. Quantum mechanical entanglement of the spin ensemble should then allow the sensitivity to increase much more than would be expected from a simple increase in the number of individual spins in the ensemble. Using the highly symmetric molecule, trimethyl phosphite, a molecule containing a central P atom surrounded by nine hydrogen atoms,

Jones
et al.

(p.
1166
, published online 23 April) quantum mechanically entangled the 10 spins (or qubits) to generate a nearly 10-fold enhancement in the magnetic field sensitivity. The results pave the way for the further development of quantum sensors.
Crystal Structure of the Nuclear Export Receptor CRM1 in Complex with Snurportin1 and RanGTP
Authors: Monecke Thomas , Güttler Thomas , Neumann Piotr , Dickmanns Achim , Görlich Dirk , Ficner Ralf
Published: April 2009

Nuclear Import/Export Receptor

Nuclear transport receptors constantly shuttle cargo between the nucleus and the cytoplasm through nuclear pore complexes. In the nucleus, RanGTP promotes the dissociation of cargo from importins, which import cargo into the nucleus (where RanGTP is guanosine 5′ triphosphate–bound Ran). Conversely, nuclear RanGTP promotes cargo-binding to exportins, which export cargo from the nucleus. Cargo is released from exportins in the cytoplasm upon hydrolysis of RanGTP. Cytoplasmically assembled RNA splicing components enter the nucleus together with an import adapter snurportin 1 (SPN1), but how then does the import adapter release its cargo and exit the nucleus to collect further cargo? The nuclear exportin CRM1 exports a broad range of substrates—including SPN1, ribosomes, and many regulatory proteins.

Monecke
et al.

(p.
1087
) describe the crystal structure of CRM1 bound to SPN1 and RanGTP. The structure shows that SPN1 cannot simultaneously bind its import cargo and the exportin CRM1, ensuring that only cargo-free SPN1 is returned to the cytoplasm. There are no direct contacts between Ran and SPN1 in the ternary complex, suggesting that RanGTP promotes cargo-binding through long-range conformational changes in CRM1.
Production and biochemical and molecular characterization of a keratinolytic serine protease from chicken feather-degradingBacillus licheniformisRPk
Authors: Fakhfakh Nahed , Kanoun Safia , Manni Laila , Nasri Moncef
Published: April 2009

A novel feather-degrading bacterium was isolated from a polluted river and identified as Bacillus licheniformis RPk. The isolate exhibited high proteinase production when grown in chicken-feather media. Complete feather degradation was achieved during cultivation. Maximum protease activity (4150 U/mL with casein as a substrate and 37.35 U/mL with keratin as a substrate) was obtained when the strain was grown in a medium containing 7.5 g/L chicken feathers, 2 g/L yeast extract, 0.5 g/L NaCl, 0.1 g/L MgSO4·7H2O, 0.7 g/L KH2PO4, and 1.4 g/L K2HPO4for 48 h with agitation of 200 rev/min at 37 °C. The major protease produced by B. licheniformis RPk was purified to homogeneity by a 3-step procedure. The molecular mass of the purified enzyme was estimated to be 32 kDa by SDS–PAGE and gel filtration. The optimum pH and temperature for the caseinolytic activity were around 11.0 and 65 °C, respectively. The optimum pH and temperature for the keratinolytic activity were 9.0 and 60 °C, respectively. The activity of the enzyme was totally lost in the presence of phenylmethylsulfonyl fluoride, which suggests that the purified enzyme is a serine protease. The thermostability of the enzyme was considerably enhanced in the presence of Ca2+at temperatures >50 °C. The kerRP gene, which encodes the keratinolytic protease, was isolated, and its DNA sequence was determined. The deduced amino acid sequence revealed that the keratinase KerRP differs from KerA of B. licheniformis PWD-1, subtilisin Carlsberg, and keratinase of B. licheniformis by 2, 4, and 62 amino acids, respectively.
Fungi from two forests of southern India: a comparative study of endophytes, phellophytes, and leaf litter fungi
Authors: Suryanarayanan T. S. , Thirumalai E. , Prakash C. P. , Rajulu M. B. Govinda , Thirunavukkarasu N.
Published: April 2009

The species diversity and distribution of 3 ecological groups of fungi (viz., foliar endophytes, phellophytes, and leaf litter fungi of 6 tree hosts of a dry thorn forest and 6 tree hosts of an evergreen forest of southern India) were studied. As the methods of sampling and the isolation procedure were maintained constant, the results could be compared across hosts and fungal assemblages. The diversity of endophytes was less in both forests, owing to host recurrence. The litter fungi showed a higher diversity in both forests when compared with endophytes or phellophytes. There was little overlap between the species assemblages of the 3 ecological groups of fungi. Hence, to be cost effective, diversity estimation exercises for fungi in the tropics should include different fungal substrates rather than one substrate (or ecological group); it appears that even small sample sizes of different substrates would provide an approximation that is the near-real species diversity, rather than using large sample sizes of any one particular indicator group of fungi.
Construction and analysis of pathogenicity island deletion mutants of Erwinia amylovora
Authors: Zhao Youfu , Sundin George W. , Wang Dongping
Published: April 2009

An easy gene-knockout technique, PCR-based one-step inactivation of chromosomal genes, is widely used in Escherichia coli and related enterobacteria to construct mutants. In this study, we adapted this technique to construct genomic island and large operon deletion mutants of Erwinia amylovora , including the 33.4 kb hrp-type III secretion (T3SS) pathogenicity island (PAI1) and the 15.8 kb amylovoran biosynthesis (AMS) operon. Deletion of 2 novel T3SS pathogenicity islands (PAI2 and PAI3) and an operon encoding a type II secretion system (T2SS) demonstrated that these determinants are not involved in virulence in plants. Co-inoculation experiments demonstrated that the hrp-T3SS and AMS deletion mutants could complement each other. These results further confirmed that the one-step inactivation technique can be used to generate large deletions in E. amylovora.
The role of heparan sulfate on adhesion of 47 and 51 kDa outer membrane proteins ofHelicobacter pylorito gastric cancer cellsThis study was done in memory of the late Dr. Roberto Carlos Vazquez-Juarez.
Authors: López-Bolaños Claudia C. , Guzmán-Murillo Maria A. , Ruiz-Bustos Eduardo , Ascencio Felipe
Published: April 2009

Helicobacter pylori is a common gastrointestinal pathogenic bacterium in humans and the usual preference for the stomach’s outer membrane proteins (OMPs) are antigens involved in the adhesion process. Through SDS–PAGE and blotting analyses, using horseradish peroxidase-labeled heparan sulfate (HRP-HS) as a probe, we identified H. pylori OMPs with affinity for heparan sulfate (OMP-HS). Biotin–streptavidin bacterial-adhesion assay was used to evaluate participation of OMP-HS in the adhesion of H. pylori to semi-confluent HeLa S3 and Kato III cell monolayers. The results provide evidence that induction of antibodies against 2 OMP-HSs (HSBP-47 and HSBP-51) could reduce binding of H. pylori to both cell lines and induce detachment of cell-bound bacteria from infected cultured cells.
Enumeration of the contaminating bacterial microbiota in unfermented pasteurized milks enriched with probiotic bacteria
Authors: Champagne C. P. , Raymond Y. , Gonthier J. , Audet P.
Published: April 2009

Pasteurized and unfermented milks supplemented with probiotic bacteria are appearing on the market. It then becomes a challenge to ascertain the undesirable contamination microbiota in the presence of a largely superior population of probiotic bacteria. A method to enumerate the contaminating microbial microbiota in such probiotic-enriched milks was developed. The probiotic cultures, Lactobacillus rhamnosus Lb-Immuni-T™ and Bifidobacterium animalis subsp. lactis BB-12®, were added to a pasteurized unfermented milk to reach a minimum of 1 billion CFU per 250 mL portion, as ascertained by plating on de Man – Rogosa – Sharpe (MRS) agar in anaerobic conditions. No growth of B. animalis subsp. lactis BB-12 was noted on plate count agar (PCA) or Petrifilm™ plates, and the presence of this culture did not affect standard plate counts (SPC) of contaminating bacteria. However, L. rhamnosus formed colonies on PCA and Petrifilm™ plates. Attempts were thus made to inhibit the growth of the probiotic lactobacilli in PCA. The addition of 2% sodium phosphate (SP) or 5% glycerophosphate (GP) inhibited the growth of the lactobacilli in broths, but pin-point colonies of L. rhamnosus Lb-Immuni-T nevertheless appeared on PCA supplemented with phosphates. SPC could be obtained on PCA + 2% SP by only counting the large colonies, but this resulted in a significant (4.4 fold) underestimation of SPC values. On Petrifilm™ AC, at dilutions 0 to 2, all colonies were considered as being contaminants, while at dilutions 3 and 4, only large colonies were counted for SPC determinations. There was a direct correlation (R2 = 0.99) between SPC values with Petrifilm™ in uninoculated milks and those obtained on probiotic-enriched milks. The high correlation obtained over the 102 to 106 CFU/mL range of SPC values show that this Petrifilm™ method is appropriate to evaluate the microbiological quality of pasteurized milks enriched with L. rhamnosus Lb-Immuni-T and B. animalis subsp. lactis BB-12.
Inhibition ofListeria monocytogenesby a combination of chitosan and divergicin M35
Authors: Benabbou R. , Zihler A. , Desbiens M. , Kheadr E. , Subirade M. , Fliss I.
Published: April 2009

The antimicrobial activities of the class IIa bacteriocin divergicin M35 and several types of chitosan against Listeria monocytogenes were quantified by agar diffusion, critical micro-dilution, and viable count and observed by electron microscopy. Antimicrobial activity of chitosan depended on its molecular mass (MM) and the pH. Three chitosans with MM values of 2, 20, and 100 kDa and 87.4% degree of deacetylation (DDA) were chosen for further study, based on high anti-listerial activity at pH 4.5. Electron microscopy suggested that the mechanism of anti-listerial activity also varied with the MM. Low-MM chitosan appeared to inhibit L. monocytogenes by affecting cell permeability and growth, whereas medium- and high-MM chitosan may form a barrier on the cell surface that prevents entry of nutrients. The minimum inhibitory concentrations (MICs) of 2, 20, and 100 kDa chitosan and divergicin M35 against a divergicin-resistant strain of L. monocytogenes (LSD 535) were 2.5, 2.5, 0.625, and 0.25 mg/mL, respectively. The combination of any of these 3 chitosans and divergicin M35 appeared to have an additive effect against L. monocytogenes, as determined by fractional inhibitory concentration (FIC) index. This study provides useful data for the development of chitosan films incorporating divergicin M35 for inhibiting L. monocytogenes in foods.
Chitinase and β-1,3-glucanase enzyme production by the mycoparasiteClonostachys roseaf.catenulataagainst fungal plant pathogens
Authors: Chatterton Syama , Punja Zamir K.
Published: April 2009

Clonostachys rosea f. catenulata (syn. Gliocladium catenulatum ) is an effective fungal biological agent against Fusarium root and stem rot and Pythium damping-off diseases on cucumber plants. Both chitinase and β-1,3-glucanase enzymes were produced when C. rosea was grown on a synthetic medium containing chitin or laminarin as a sole carbon source, respectively. Chitinase production was also induced by Fusarium cell walls, while β-1,3-glucanase activity was induced by both Fusarium and Pythium cell walls, as well as by growth on homogenized cucumber roots and on low-carbon media. Mycelial growth of Fusarium and Pythium, when exposed to C. rosea culture filtrates that contain glucanase activity, was significantly reduced compared with the controls, and cell walls of both pathogens were degraded. On excised cucumber roots, hyphae of C. rosea formed appressorium-like structures and coiled around hyphae of Pythium. In culture, C. rosea caused localized degradation of Fusarium hyphae. Cucumber root tissues colonized by C. rosea showed higher levels of β-1,3-glucanase activity at 7 days post-application compared with untreated controls. To determine if this activity was derived from C. rosea, glucanase isoforms were separated on activity gels. Fungal culture filtrates and root extracts contained the same predominant 20 kDa isoform. Reverse-transcription polymerase chain reaction (RT-PCR) using primers designed to amplify a β-1,3-glucanase gene in C. rosea confirmed glucanase expression on roots. These results show that C. rosea produces β-1,3-glucanase in situ, which can degrade hyphae of Fusarium and Pythium and contribute to biological control efficacy.