bluuebunny/crossref_metadata_2025 huggingface dataset:
Approximate Synthesis of Spatial Linkages
Authors: Denavit J. , Hartenberg R. S.
Published: October 2011

Freudenstein’s approximate synthesis of planar four-bar linkages is generalized to spatial linkages, and the conditions under which this generalization is applicable are expressed. Three cases of synthesis of spatial linkages to generate functions of one variable between nonparallel axes are considered in detail: (a) The spherical four-bar linkage; (b) a variation of the four-bar linkage in which two turning pairs are replaced by ball-and-socket joints, a linkage which may be designed to generate arbitrary functions with up to seven accuracy points; and (c) a second variation of the four-bar linkage where three turning pairs are replaced by cylinder pairs, a linkage capable of being designed to generate a variable-pitch helical motion with three accuracy points.
Heat-Exchanger Tube-Sheet Design—3. U-Tube and Bayonet-Tube Sheets
Authors: Gardner Karl A.
Published: October 2011

Tube sheets of U-tube and bayonet-tube exchangers differ from those of floating-head exchangers in that they receive no external support from the staying or column action of the tubes. The strengthening effect of tube-bending reaction is here investigated, evaluated quantitatively, and presented in the form of simple design factors. These factors are functions of a parameter ua, a measure of the relative “barreling” rigidity of the tube bundle as compared to the flexural rigidity of the tube sheet. With stiff tubes and flexible tube sheets (high ua) the reinforcement due to tube bending is considerable and, in the central region of the tube sheet, the deflection and curvature are essentially independent of any tube-sheet property. At low ua the benefit gained is negligible.
Correlation of Theoretical and Photothermoelastic Results on Thermal Stresses in Idealized Wing Structures
Authors: Tramposch Herbert , Gerard George
Published: October 2011

After a rather complete exploratory program described in previous papers, the photothermoelastic method was applied to the experimental evaluation of thermal-stress theories. The new technique was correlated with several theories which analyzed the transient thermal stresses in idealized wing structures of high-speed aircraft. Various theories were investigated which represented the same idealized wing models and differed from each other only in the simplifying assumptions regarding the temperature distributions in skin and webs. The theories were evaluated by duplicating the boundary and initial conditions on plastic models and then by correlating the theories with the observed fringe orders in nondimensional form. A significant general conclusion was reached after correlating the available theories and experimental results. Owing to simplifying assumptions concerning the thermal behavior in the flanges, thermal stresses predicted by the available theories are all higher than the experimental observation. In some cases the discrepancy is as great as 30 per cent.
Transient Thermal Stresses in a Semi-Infinite Slab
Authors: Jaunzemis W. , Sternberg E.
Published: October 2011

This investigation is concerned with the transient temperature and thermal-stress distribution generated in a semi-infinite slab if a finite segment of its edge is subjected to a sudden uniform change in temperature. The slab is supposed to be free from external loads and its faces are assumed to be insulated. Exact solutions in series form are obtained both for the heat-conduction problem and for the associated thermoelastic problem. The latter is treated quasi-statically within the classical two-dimensional theory of elasticity. The thermal stresses appropriate to the generalized plane-stress solution vanish identically in the limit as time tends to infinity. The space and time dependence of these stresses is examined in some detail with a view toward tracing the evolution of this well-known, steady-state degeneracy. Finally, the results corresponding to an instantaneous heating or cooling of a portion of the boundary are used to study the effect upon the stresses of gradual changes in the surface temperature.
Note on the Assessment of Flow Disturbances at a Blunt Body Traveling at Supersonic Speeds Owing to Flow Disturbances in Free Stream
Authors: Morkovin M. V.
Published: October 2011

For the purposes of assessing the magnitude of flow disturbances which would affect conditions on a blunt nose of a body moving at supersonic speeds, the detached shock is approximated by a purely normal shock. The disturbances downstream of the shock are expressed in terms of the “free-stream” disturbances by considering sinusoidal fluctuations. Pressure fluctuations generated by interactions of entropy-temperature disturbances with the normal shock may be considerable at high Mach numbers, but their effect on the transition of a laminar boundary layer to a turbulent one is a matter of speculation. However, conjectures that reflections of such pressure waves between the body and the shock wave might lead to high resonant amplifications are definitely disproved.
On the Annular Damper for a Freely Precessing Gyroscope
Authors: Carrier G. F. , Miles J. W.
Published: October 2011

The dynamics of a damper that has been used to eliminate the free precession of flying, spinning objects are analyzed. There are three regimes in which the details of the mechanisms by which the viscous fluid dissipates the precessional energy differ markedly, and the fluid motion and energy-dissipation rate are described quantitatively for each regime.
A Study of the Stability of Externally Pressurized Gas Bearings
Authors: Licht Lazar , Elrod Harold
Published: October 2011

The subject of this paper is the stability of externally pressurized gas bearings. The pertinent equations of motion are linearized and the stability criteria stated in terms of small deviations from the equilibrium operating point. The flow in the bearing clearance is treated on a distributed rather than on a lumped-parameter basis. Results obtained from present analysis when compared with those previously arrived at by means of simplified analyses [1, 3] show a marked divergence in the limiting values of parameters which influence the stability of the bearing. These results and divergences are discussed in terms of permissible compression volume, pressure ratios, supply-nozzle size, length of annular clearance, and bearing mass.
The Vibration Response of a Linear Undamped System Resting on a Nonlinear Spring
Authors: Paslay P. R. , Gurtin M. E.
Published: October 2011

The steady-state, undamped-displacement-amplitude response of a linear system on a single nonlinear spring due to a force excitation which varies sinusoidally with time is investigated. The force-displacement relation of the spring is F=k(x+εx3)(1) The Fourier component of the displacement-amplitude response of the system at the forcing frequency and its third harmonic are considered.
Elastic Equilibrium of a Plate With a Reinforced Elliptical Hole
Authors: Levin Eugene
Published: October 2011

An infinite thin plate with an elliptical hole reinforced by a confocal elliptical ring is subjected to loads in the plane. A solution to the generalized plane-stress problem is obtained using the complex variable techniques of Muskhelishvili. The result is presented in a form well suited to evaluation by digital computers. Specialization to a circular hole with a negligibly thin reinforcement is shown to be in agreement with results obtained by other authors.
A Method of Solution for the Elastic Quarter-Plane
Authors: Hete´nyi M.
Published: October 2011

It is shown in this paper that for given loads on the elastic quarter-plane the prescribed boundary conditions can be fulfilled by repeated superposition of known solutions for the elastic half-plane. This leads to a sequence of infinite integrals of a simple recursion pattern. The solution is exact, since the sequence may be continued to obtain any required accuracy. Solutions are derived in this manner for three types of boundary loads: (a) concentrated normal force, (b) concentrated tangential force, and (c) partially distributed uniform loading.
Thermal Stress in a Viscoelastic-Plastic Plate With Temperature-Dependent Yield Stress
Authors: Landau H. G. , Weiner J. H. , Zwicky E. E.
Published: October 2011

Equations are given for the determination of transient and residual stresses in plates subject to transient temperature distributions, based on the assumption of a viscoelastic, perfectly plastic material obeying a von Mises temperature-dependent yield condition. A numerical procedure for integrating the equations is developed and applied to the case of a symmetrically cooled plate. It is found that, for steel, viscoelasticity has little effect on the residual stress distribution, but the temperature dependence of yield stress is important. The types of residual stress distribution after cooling are similar to those for an elastic-plastic material with constant yield stress, and for this case the residual stress is given approximately by formulas developed earlier for a slowly varying heat input.
A Method of Numerical Evaluation of a Large Determinant
Authors: Crossley F. R. E. , Germen U¨stu¨n
Published: October 2011

When solving problems in the vibration of a close-coupled system, there arises the need to expand a tridiagonal determinant of the type of equation (1). A very quick and accurate means of accomplishing this expansion is provided by the following numerical procedure, which can readily be adapted to computer programming.
The Additional Deflection of a Cantilever Due to the Elasticity of the Support
Authors: O’Donnell W. J.
Published: October 2011

A beam is cantilevered from a semi-infinite solid with neutral axis normal to its bounding plane (two-dimensional problem). Deformation of the supporting solid allows the beam to rotate about the built-in end, producing a deflection in addition to that caused by bending and shear in the beam itself. Results of tests designed to measure this additional deflection are presented and compared with various theoretical values. Calculated deflections, based on classical bending and shear-deflection theory, are also compared with measured deflections. An experimentally verified expression for the additional deflection of a cantilever due to the elasticity of the support is given.
Elastic Instability of Rectangular Sandwich Panel of Orthotropic Core With Different Face Thicknesses and Materials
Authors: Chang C. C. , Ebcioglu I. K.
Published: October 2011

This paper treats the instability of rectangular sandwich panels with nonisotropic cores and faces of different materials or thicknesses. The simply supported panel is loaded with a uniform edge compression. The solution is expressed in terms of a major buckling coefficient, given as the ratio of the critical lateral buckling load to the critical cylindrical buckling load, which is a function of several nondimensional parameters. A single family of curves shows the buckling behavior for all parameters. The effect of a moderate temperature differential between the two faces can be approximately considered by modifying their moduli of elasticity in accordance with their temperature levels. Besides the regular panel instability, a zone of core shear instability is determined and discussed in detail. Numerical examples are presented to illustrate the application of the analysis.
Modeling of Large Transient Elastic and Plastic Deformations of Structures Subjected to Blast Loading
Authors: Baker W. E.
Published: October 2011

In this paper, a model law is developed for scaling of response to blast loading of structures which undergo large elastic and plastic deformations. The geometrical scaling of response predicted by this law is verified by a series of experiments on small cantilever beams.
Shock Spectra of a Nonlinear System
Authors: Thomson W. T.
Published: October 2011

The peak response under pulse excitation, of a single-degree-of-freedom system with nonlinear spring approximated by two straight lines, is analytically determined. Shock spectra for the step and delta function are developed with damping as parameter. For the rectangular pulse excitation, the shock spectra for zero damping are presented with pulse duration as a parameter. For the arbitrary pulse shape, a general procedure is discussed and illustrated for the sine pulse of differing pulse duration. Generalized phase-plane plots associated with the problem are included. The shock spectra presented are applicable only when the first peak corresponds to the maximum response, thereby avoiding the questions of unloading.
Forced Flexural Vibrations of Sandwich Plates in Plane Strain
Authors: Yu Yi-Yuan
Published: October 2011

On the basis of the new flexural theory of elastic sandwich plates recently developed [1–3], the problem of general forced flexural vibration of sandwich plates in the plane-strain case is solved. The classical method of separation of variables combined with the Mindlin-Goodman procedure [4] for treating time-dependent boundary conditions is used. As an example, the results are made use of in solving the problem of a simply supported sandwich plate in plane strain with one of the two end sections prescribed a transverse deflection varying with time.
Extensional Vibrations and Waves in a Circular Disk and a Semi-Infinite Plate
Authors: Gazis D. C. , Mindlin R. D.
Published: October 2011

A set of approximate equations of extensional motion of elastic plates is solved for the case of axially symmetric vibrations of a circular disk and the results are compared with experiments performed by E. A. G. Shaw. Special attention is given to a new mode of vibration, discovered by Shaw, in which the deformation is predominantly at the edge of the disk. It is shown how this mode arises from the complex conjugate roots of the frequency equation of an infinite plate. The properties of the edge-mode are examined in detail in a study of the reflection of straight-crested extensional waves at the edge of a semi-infinite plate.
On a Special Class of Self-Sustained Oscillations
Authors: Klotter K. , Kreyszig E.
Published: October 2011

This paper deals with the “modified van der Pol differential equations” q¨ − (sgn q˙) (δ/2)q˙2 h(q) + κ2f(q) = 0, where h(q) and f(q) are suitable functions. It is shown that there exists a unique limit cycle. For the limit amplitude both lower and upper bounds are established in the case of unrestricted values δ. For small values δ the limit amplitude can be calculated immediately.
Stress-Displacement Relations for Shell Membranes in Oblique Co-Ordinates
Authors: Galletly G. D.
Published: October 2011

In this note the relations between the internal forces in a shell membrane and the corresponding deformations are derived for shells with oblique rectilinear planforms. The derivation is an extension of that previously given for rectangular planforms.
Transient Heat Conduction in a Rod of Finite Length With Variable Thermal Properties
Authors: Chu W. H. , Abramson H. N.
Published: October 2011

This paper presents a theoretical solution for transient heat conduction in a rod of finite length with variable thermal properties. A numerical procedure is developed and the results of one example are presented and compared with the corresponding solution for the case of constant properties. Application to the problem of determination of thermophysical properties is discussed briefly.
Thermal Stresses in an Elastic, Work-Hardening Sphere
Authors: Hwang Chintsun
Published: October 2011

In this paper, a method is presented for obtaining the transient thermal-stress distribution and the residual stresses in a spherical body where the time-dependent temperature distribution is symmetrical with respect to the center of the sphere. The material is assumed to be elastoplastic, while in the plastic range it work-hardens isotropically. The von Mises yield condition is used. The thermal and mechanical properties of the material are assumed to be temperature independent. The problem is reduced to a single nonlinear differential equation which is solved numerically on the NCR 304 digital computer. Several sets of numerical data representing various degrees of work-hardening in the spherical bodies during a cooling process are presented.
Sinusoidal Excitation of a System With Bilinear Hysteresis
Authors: Caughey T. K.
Published: October 2011

Many physical systems exhibit hysteresis which may be adequately described by a bilinear hysteresis model. This paper considers the response of such a system to sinusoidal excitation. It is shown that the system exhibits a soft-type resonance with stable, single-valued response curves. For such a system it is shown that there exists a critical value of the excitation, above which unbounded resonance occurs.
Random Excitation of a System With Bilinear Hysteresis
Authors: Caughey T. K.
Published: October 2011

An analysis is made of the response of a system with bilinear hysteresis to random excitation. It is shown that for moderately large inputs, the additional damping created by the bilinear hysteresis decreases the mean squared deflection compared with that for a linear system with the same viscous damping. However, for large inputs, the decrease in the stiffness of the system due to the bilinear hysteresis causes the mean squared deflection to increase over that for the equivalent linear system.
Vibrations of Elastic Sandwich Cylindrical Shells
Authors: Yu Yi-Yuan
Published: October 2011

Previous treatment of vibration of elastic sandwich plates [1–6] is extended in this paper to the vibration study of sandwich cylindrical shells. General theory is developed. Simplified equations are applied to the investigation of axially symmetric and torsional vibrations.
Flexural Stress Waves in an Infinite Elastic Plate Due to a Suddenly Applied Concentrated Transverse Load
Authors: Miklowitz Julius
Published: October 2011

The problem solved is that of an infinite plate subjected to a suddenly applied concentrated transverse shear load. The solution is derived from a plate theory that incorporates, in addition to bending, the effect of shear force and rotatory inertia on the deflection. These added effects give the present theory true wave character along with greater accuracy in the waves predicted. Numerical evaluation of the solution brings out the effects of dispersion and distortion on the moment and shear-force response of the plate. A criterion is developed for judging the accuracy of this response. It is based on a comparison, employing the stationary phase method, of the present approximate and exact (three-dimensional) theories.
Plastic Analysis of Circular Conical Shells
Authors: Hodge P. G.
Published: October 2011

A right circular conical shell of edge angle α is subjected to a concentrated load Q directed along the axis. The collapse load is found to be Q = 2πM0 cos2 α, independently of the size or support conditions of the shell. Some solutions are also obtained for the case where the load is distributed over a finite area. Bounds are found on the collapse load of a general rotationally symmetric shell under a concentrated load.
The Penetration of Hard-Steel Spheres Into Plane Metal Surfaces
Authors: Goldsmith Werner , Lyman Peter T.
Published: October 2011

An experimental investigation was undertaken to determine the force-indentation relations governing the contact of hard-steel balls and plane surfaces of various metals both under static and dynamic conditions, the latter involving the Hopkinson-bar technique, with maximum elastic strain rates of 500 sec−1. Excellent correlation was obtained between the measured permanent crater diameter at the contact point and that calculated from strain-gage data by means of an equation treating the bar as a one-dimensional member. A comparison also was effected between the static and dynamic force-indentation curves, the Hertz law of contact, and a relation based upon the concept of a constant flow pressure in the plastic regime.
Flow of Liquid Metal Past a Porous Flat Plate
Authors: Horvay G.
Published: October 2011

A simple boundary-layer approximation formula is derived for the temperature distribution in liquid metal which flows past a porous flat plate at zero incidence at velocity U and is sucked into it at velocity V.
Analysis Methodology for Vortex-Induced Motion (VIM) of a Monocolumn Platform Applying the Hilbert–Huang Transform Method
Authors: Gonçalves Rodolfo T. , Franzini Guilherme R. , Rosetti Guilherme F. , Fujarra André L. C. , Nishimoto Kazuo
Published: October 2011

Vortex-induced motion (VIM) is a highly nonlinear dynamic phenomenon. Usual spectral analysis methods, using the Fourier transform, rely on the hypotheses of linear and stationary dynamics. A method to treat nonstationary signals that emerge from nonlinear systems is denoted Hilbert–Huang transform (HHT) method. The development of an analysis methodology to study the VIM of a monocolumn production, storage, and offloading system using HHT is presented. The purposes of the present methodology are to improve the statistics analysis of VIM. The results showed to be comparable to results obtained from a traditional analysis (mean of the 10% highest peaks) particularly for the motions in the transverse direction, although the difference between the results from the traditional analysis for the motions in the in-line direction showed a difference of around 25%. The results from the HHT analysis are more reliable than the traditional ones, owing to the larger number of points to calculate the statistics characteristics. These results may be used to design risers and mooring lines, as well as to obtain VIM parameters to calibrate numerical predictions.
Simulation of Heat Transfer and System Behavior in a Supercritical CO2 Based Thermosyphon: Effect of Pipe Diameter
Authors: Chen Lin , Zhang Xin-Rong
Published: October 2011

This paper deals with the natural convective circulation thermosyphon with supercritical CO2 flow. New heat transport model aiming at supercritical thermosyphon heat transfer and stability is proposed and numerically studied. Two-dimensional rectangular natural circulation loop model is set up and the effect of pipe diameter is systematically analyzed. Finite volume method is used to solve the conservative equations with supercritical turbulence model incorporated. It is found that supercritical CO2 thermosyphon can achieve high Reynolds flow as 104–105 even temperature differences between source and sink is small. Stabilized flow is found for larger pipe diameter group due to the developed flow field and enhanced heat transfer. Heat transport at cooler side can be enhanced at higher operating temperature and be critical for the stabilization of the supercritical thermosyphon. Correlations of flow and heat transfer are reexamined and good agreements with classical reports are also obtained in the present study.
Effect of Surface Microstructure on Microchannel Heat Transfer Performance
Authors: Liu Yang , Cui Jing , Li WeiZhong , Zhang Ning
Published: October 2011

In this paper, forced convection heat transfer occurring in microchannels with different microstructures is investigated numerically. It is found that vortices will appear in the microstructure grooves. The influence of microchannel geometries on heat transfer performance is evaluated by Nusselt number and the entrance effect is noted for all geometries. Compared with the plain plate surface, a much more moderate decrease of local Nusselt number can be found for all the grooved microstructures, indicating more uniform heat transfer intensity along the flowing direction. The results also suggest that the heat transfer performance improves with inlet Reynolds number. The V-shaped grooved microstructure possesses the highest heat transfer performance. Compared with the plain plate surface, averaged Nusselt number can be increased by about 1.6 times. Through the field synergy principle analysis, we find that it is the synergy between temperature gradient and velocity that results in different heat transfer performance for different microstructures.
Morton Effect Induced Synchronous Instability in Mid-Span Rotor–Bearing Systems, Part 2: Models and Simulations
Authors: Guo Zenglin , Kirk Gordon
Published: October 2011

The mechanism of the Morton Effect induced synchronous instability has been discussed in Part 1, using an assumption of isotropic linear bearings. The second part of the current study will now focus on the more realistic systems, mid-span rotors supported by the hydrodynamic journal bearings. First, the models to calculate the thermal bending of the shaft and the temperature distribution across the journal surface are established. This can be used to calculate the equivalent thermal imbalance. The calculations of the temperature difference and its equivalent thermal imbalance using hydrodynamic plain journal bearing models are conducted and discussed with the comparison to the analytical results obtained in Part 1. It shows that the thermal imbalance induced by the Morton Effect may increase to the level of the mechanical imbalance and then its influence on the system stability should be included. The suggested thermal bending model also partially explains that the mid-span rotors are less liable to be influenced by the Morton Effect induced instability than are the overhung configurations, because of the restraining effect between two supports. Finally, a symmetric mid-span rotor - hydrodynamic journal bearing system is calculated to show its stability performance. The results show the inclusion of the Morton Effect may lead to an unstable operation of the system. Considering the existence of the oil film self-induced vibration due to the dynamic characteristics of fluid film bearings, the Morton Effect may make a further negative impact on the stability of the system. The simulation results of the unbalance response show that the Morton Effect changes the shapes of the whirling orbits and makes them no longer the standard elliptical orbits around the static equilibriums.
Minimizing Contamination in Commercial Mass Production of Metal Injection Molded Pure Titanium
Authors: Chalermkarnnon P. , Manonukul A. , Muenya N. , Nakayama H. , Fujiwara M.
Published: October 2011

Metal injection molding (MIM) has been used in manufacturing highly complex metal parts but has had far less application for titanium which is a reactive metal. The implementation of titanium MIM on a mass production scale still raises many difficulties due to the contamination from processes, especially in case of manufacturing titanium parts on existing steel-based part production lines. The effects of material contamination in commercially-pure (CP) titanium parts have been studied and the trial production of titanium parts on a commercial MIM production line has been carried out. Steel-based feedstocks gathering on titanium green parts diffused into the titanium giving rise to liquid phase sintering, which disfigured the appearance of the titanium products. The trial production of titanium parts on a steel-based mass production line resulted in products with poor mechanical properties compared with those produced under laboratory conditions. The contamination by steel during the process resulted in the formation of a Ti–Fe solid solution phase at localized areas in the parts, decreasing the elongation to below 4%. Methods to reduce contamination in the mass production line have been carefully applied and acceptable properties, e.g., elongation about 18%, of titanium parts successfully achieved. CP titanium parts can be manufactured via well-controlled production in the steel-based MIM factory.
Fabrication of ultra-high-density nanodot array patterns (∼3 Tbits/in.2) using electron-beam lithography
Authors: Lee Min-Hyun , Kim Hyun-Mi , Cho Seong-Yong , Lim Kipil , Park Soo-Yeon , Jong Lee Jae , Kim Ki-Bum
Published: October 2011

The authors fabricated 15 nm pitch scale high-density dot patterns on a Si substrate using a hydrogen silsesquioxane electron-beam (e-beam) resist, vacuum treatment as a prebake, and vertical sidewall etching. The e-beam lithography was performed at 100 keV. The dot density fabricated was close to 3 Tbits/in.,2 which is one of the highest density patterns reported thus far. The process window was quite wide and the result can be easily and routinely duplicated.
Individualizing Asthma Treatment
Authors: Damani Samir
Published: October 2011

A genome-wide association study identifies a new predictive genetic variant for response to a common asthma treatment.
Spotlight on the Silent Lady Killer
Authors: Evans-Molina Carmella
Published: October 2011

A new method fluorescently labels ovarian tumors for easy surgical removal.
Genome Sequence of Mycoplasma capricolum subsp. capripneumoniae Strain M1601
Authors: Chu Yuefeng , Gao Pengchen , Zhao Ping , He Ying , Liao Nancy , Jackman Shaun , Zhao Yongjun , Birol Inanc , Duan Xiaobo , Lu Zhongxin
Published: October 2011

Mycoplasma capricolum
subsp.
capripneumoniae
is the causative agent of contagious caprine pleuropneumonia, a devastating disease of goats listed by the World Organization for Animal Health. Here we report the first complete genome sequence of this organism (strain M1601, a clinically isolated strain from China).
Genome Sequence of Desulfosporosinus sp. OT, an Acidophilic Sulfate-Reducing Bacterium from Copper Mining Waste in Norilsk, Northern Siberia
Authors: Abicht Helge K. , Mancini Stefano , Karnachuk Olga V. , Solioz Marc
Published: October 2011

We have sequenced the genome of
Desulfosporosinus
sp. OT, a Gram-positive, acidophilic sulfate-reducing Firmicute isolated from copper tailing sediment in the Norilsk mining-smelting area in Northern Siberia, Russia. This represents the first sequenced genome of a
Desulfosporosinus
species. The genome has a size of 5.7 Mb and encodes 6,222 putative proteins.
Genome Sequence of Leuconostoc carnosum KCTC 3525
Authors: Nam Seong-Hyeuk , Kim Aeri , Choi Sang-Haeng , Kang Aram , Kim Dong-Wook , Kim Ryong Nam , Kim Dae-Soo , Park Hong-Seog
Published: October 2011

We announce the draft genome sequence of the type strain
Leuconostoc carnosum
KCTC 3525 (3,234,408 bp with a G+C content of 40.9%), one of the most prevalent lactic acid bacteria present during the manufacturing process of vacuum-packaged meats, which consists of 2,407 large contigs (>500 bp in size). The genome sequence was obtained by a whole-genome shotgun strategy using Roche 454 GS (FLX Titanium) pyrosequencing, and all of the reads were assembled using Newbler Assembler 2.3.
Genome Sequence of Corynebacterium glutamicum S9114, a Strain for Industrial Production of Glutamate
Authors: Lv Yangyong , Wu Zhanhong , Han Shuangyan , Lin Ying , Zheng Suiping
Published: October 2011

Here we report the genome sequence of
Corynebacterium glutamicum
S9114, an industrial producer widely used in production of glutamate in China. Preliminary comparison with the sequences of the
Corynebacterium glutamicum
strains ATCC 13032 and R revealed some notable mutagenesis that might be related to the high yield of glutamate.
Satellite RNA-Derived Small Interfering RNA satsiR-12 Targeting the 3′ Untranslated Region of Cucumber Mosaic Virus Triggers Viral RNAs for Degradation
Authors: Zhu Hui , Duan Cheng-Guo , Hou Wei-Na , Du Quan-Sheng , Lv Dian-Qiu , Fang Rong-Xiang , Guo Hui-Shan
Published: October 2011

RNA silencing provides protection against RNA viruses by targeting both the helper virus and its satellite RNA (satRNA). Virus-derived small interfering RNAs (vsiRNAs) bound with Argonaute (AGO) proteins are presumed participants in the silencing process. Here, we show that a vsiRNA targeted to virus RNAs triggers the host RNA-dependent RNA polymerase 6 (RDR6)-mediated degradation of viral RNAs. We confirmed that satRNA-derived small interfering RNAs (satsiRNAs) could be associated with different AGO proteins
in planta
. The most frequently cloned satsiRNA, satsiR-12, was predicted to imperfectly match to
Cucumber mosaic virus
(CMV) RNAs in the upstream area of the 3′ untranslated region (3′ UTR). Moreover, an artificial satsiR-12 (asatsiR-12) mediated cleavage of a green fluorescent protein (GFP) sensor construct harboring the satsiR-12 target site. asatsiR-12 also mediated reduction of viral RNAs in 2b-deficient CMV (CMVΔ2b)-infected
Nicotiana
benthamiana
. The reduction was not observed in CMVΔ2b-infected RDR6i plants, in which RDR6 was silenced. Following infection with 2b-containing CMV, the reduction in viral RNAs was not observed in plants of either genotype, indicating that the asatsiR-12-mediated reduction of viral RNAs in the presence of RDR6 was inhibited by the 2b protein. Our results suggest that satsiR-12 targeting the 3′ UTR of CMV RNAs triggered RDR6-dependent antiviral silencing. Competition experiments with wild-type CMV RNAs and anti-satsiR-12 mutant RNA1 in the presence of 2b and satRNA demonstrate the inhibitory effect of the 2b protein on the satsiR-12-related degradation of CMV RNAs, revealing a substantial suppressor function of the 2b protein in native CMV infection. Our data provide evidence for the important biological functions of satsiRNAs in homeostatic interactions among the host, virus, and satRNA in the final outcome of viral infection.
The Sociomicrobiology of Antivirulence Drug Resistance: a Proof of Concept
Authors: Mellbye Brett , Schuster Martin
Published: October 2011

Antivirulence drugs disarm rather than kill pathogens and are thought to alleviate the problem of resistance, although there is no evidence to support this notion. Quorum sensing (QS) often controls cooperative virulence factor production and is therefore an attractive antivirulence target, for which inhibitors (QSI) have been developed. We designed a proof-of-principle experiment to investigate the impact of bacterial social interactions on the evolution of QSI resistance. We cocultured
Pseudomonas aeruginosa
QS-deficient mutants with small proportions of the QS-proficient wild type, which in the absence of QSI mimic QSI-sensitive and -resistant variants, respectively. We employed two different QS-dependent nutrients that are degraded by extracellular (public) and cell-associated (private) enzymes. QS mutants (QSI-sensitive mimics) behaved as social cheaters that delayed population growth and prevented enrichment of wild-type cooperators (QSI-resistant mimics) only when nutrient acquisition was public, suggesting that QSI resistance would not spread. This highlights the potential for antivirulence strategies that target cooperative behaviors and provides a conceptual framework for future studies.
New Antibody Weapons against an Old Foe
Authors: Benach Jorge L.
Published: October 2011

Antibodies have been used in a diagnostic capacity for many diseases and for identifying serotypes within single species of pathogens, notably between the multiple capsular polysaccharide serotypes ofStreptococcus pneumoniae. For many years, the functions of antibodies in infection were thought to be limited to the opsonization of microorganisms followed by phagocytosis and to the fixing of complement. The thought that antibodies could have other functions has emerged only recently. The study by Yano and coworkers from the laboratory of Liise-anne Pirofski published inmBio[M. Yano, S. Gohil, J. R. Coleman, C. Manix, and L.-A. Pirofski, mBio 2(5):e00176-11, 2011] identifies one mechanism whereby nonopsonic antibodies enhance the transformation competence of twoS. pneumoniaeserotypes, which leads to an increase in genetic exchange and bacterial variability with a resulting population reduction through fratricide. These new and revealing antibody functions will add another chapter to the burgeoning story of the diversity and versatility of the immune response to bacteria.
Fluid inclusion and stable isotope constraints on the origin of Wernecke Breccia and associated iron oxide – copper – gold mineralization, Yukon
Authors: Hunt Julie A. , Baker Tim , Cleverley James , Davidson Garry J. , Fallick Anthony E. , Thorkelson Derek J.
Published: October 2011

Iron oxide – Cu ± Au ± U ± Co (IOCG) mineralization is associated with numerous Proterozoic breccia bodies, collectively known as Wernecke Breccia, in Yukon Territory, Canada. Multiphase breccia zones occur in areas underlain by Paleoproterozoic Wernecke Supergroup metasedimentary rocks and are associated with widespread sodic, potassic, and carbonate alteration assemblages. Fluid inclusion data indicate syn-breccia fluids were hot (185–350 °C) saline (24–42 wt.% NaCl equivalent) NaCl–CaCl2–H2O brines. Estimates of fluid pressure vary from 0.4 to 2.4 kbar (1 kbar = 100 MPa). Carbon and oxygen isotopic compositions of breccia-related carbonates range from ~–11‰ to +1.5‰ (Pee Dee belemnite (PDB)) and –2‰ to 20‰ (Vienna standard mean ocean water (V-SMOW); δ18Owater ~–8‰ to +15‰), respectively. δ13C and δ18O values for host Wernecke Supergroup limestone/dolostone vary from ~–2‰ to 1.6‰ and 12‰ to 25‰, respectively. Sulfur isotopic compositions of hydrothermal sulfides and sulfate vary from ~–12‰ to +13‰ and +8‰ to +17‰ (Cañon Diablo Troilite (CDT)), respectively. Syn-breccia biotite, muscovite, and actinolite have δD and δ18O values of ~–141‰ to –18‰ and +7‰ to +12‰ (V-SMOW; δ18Owater ~7‰ to 11‰), respectively. The Wernecke Breccias and the associated IOCG mineralization appear to have formed from largely nonmagmatic fluids — based on isotopic, fluid inclusion, and geological data. The emerging hypothesis is that periodic overpressuring of dominantly formational/metamorphic water led to repeated brecciation and mineral precipitation. The weight of overlying sedimentary rocks led to elevated fluid temperatures and pressures; fluid flow may have been driven by tectonics and (or) gravity with metals scavenged from host strata.
First evidence of percids (Teleostei: Perciformes) in the Miocene of North America
Authors: Murray Alison M. , Divay Julien D.
Published: October 2011

Miocene sediments of southern Saskatchewan have long been known for the mammalian fauna they have produced, but little or nothing has been reported of the associated fish material. Recent examination of this material collected over half a century ago has revealed the presence of a walleye fish. Walleyes and other members of the family Percidae had previously been thought to have arrived in North America as late as the Pleistocene, and only in the last few years has evidence been found demonstrating their existence in North America in the Pliocene. The Pliocene material, from Arctic Canada, indicated that percids may have invaded North America from Europe during the late Tertiary via the Bering Isthmus. The material presented here shows that in fact percids were already in more southern areas of Canada about 10 million years prior to the Arctic walleye.
Do β3-adrenergic receptors play a role in guinea pig detrusor smooth muscle excitability and contractility?
Authors: Afeli Serge A. Y. , Hristov Kiril L. , Petkov Georgi V.
Published: October 2011

In many species, β3-adrenergic receptors (β3-ARs) have been reported to play a primary role in pharmacologically induced detrusor smooth muscle (DSM) relaxation. However, their role in guinea pig DSM remains controversial. The aim of this study was to investigate whether β3-ARs are expressed in guinea pig DSM and to evaluate how BRL37344 and L-755,507, two selective β3-AR agonists, modulate guinea pig DSM excitability and contractility. We used a combined experimental approach including RT-PCR, patch-clamp electrophysiology, and isometric DSM tension recordings. β3-AR mRNA message was detected in freshly isolated guinea pig DSM single cells. BRL37344 but not L-755,507 caused a slight decrease in DSM spontaneous phasic contraction amplitude and frequency in a concentration-dependent manner. In the presence of atropine (1 μM), only the spontaneous phasic contractions frequency was inhibited by BRL37344 at higher concentrations. Both BRL37344 and L-755,507 significantly decreased DSM carbachol-induced phasic and tonic contractions in a concentration-dependent manner. However, only BRL37344 inhibitory effect was partially antagonized by SR59230A (10 μM), a β3-AR antagonist. In the presence of atropine, BRL37344 and L-755,507 had no inhibitory effect on electrical field stimulation-induced contractions. Patch-clamp experiments showed that BRL37344 (100 μM) did not affect the DSM cell resting membrane potential and K+ conductance. Although β3-ARs are expressed at the mRNA level, they play a minor to no role in guinea pig DSM spontaneous contractility without affecting cell excitability. However, BRL37344 and L-755,507 have pronounced inhibitory effects on guinea pig DSM carbachol-induced contractions. The study outlines important DSM β3-ARs species differences.
Synthesis and Characterization of 1D Ceria Nanomaterials for CO Oxidation and Steam Reforming of Methanol
Authors: Chowdhury Sujan , Lin Kuen-Song
Published: October 2011

Novel one-dimensional (1D) ceria nanostructure has been investigated as a promising and practical approach for the reforming of methanol reaction. Size and shape of the ceria nanomaterials are directly involved with the catalytic activities. Several general synthesis routes as including soft and hard template-assemble phenomenon for the preparation of 1D cerium oxide are discussed. This preparation phenomenon is consisting with low cost and ecofriendly. Nanometer-sized 1D structure provides a high-surface area that can interact with methanol and carbon-monoxide reaction. Overall, nanometer-sized structure provides desirable properties, such as easy recovery and regeneration. As a result, the use of 1D cerium has been suitable for catalytic application of reforming. In this paper, we describe the 1D cerium oxide syntheses route and then summarize their properties in the field of CO oxidation and steam reforming of methanol approach.
A Case of Worsening Deep Cerebral Venous Sinus Thrombosis Managed by Intrasinus Thrombolysis
Authors: Sood Nidhi , Sood Nikhil , Talkad Arun
Published: October 2011

Cerebral venous sinus thrombosis (CVST) is an uncommon condition with severe consequences. Although we do not know the exact incidence and prevalence of CVST, it is an important diagnosis. Over the past decade, it has been diagnosed more frequently due to greater awareness and availability of noninvasive diagnostic techniques. Furthermore, routine diagnostic neuroimaging has been used to monitor the clinical progress of these patients, especially in deteriorating cases. In order to decrease morbidity and mortality, an understanding of CVST treatment options is important. Treatment of extensive intracranial venous sinus thrombosis with intrasinus infusion of recombinant tissue plasminogen activator (rt-PA) is relatively controversial as there are no clear guidelines in regards to appropriate therapeutic management. We report a case of successful intrasinus thrombolysis of deep cerebral sinus thrombosis (DCST) resulting in rapid radiographic improvement associated with complete clinical recovery.
Achievements and Challenges of CdS/CdTe Solar Cells
Authors: Fang Zhou , Wang Xiao Chen , Wu Hong Cai , Zhao Ce Zhou
Published: October 2011

Thin film CdS/CdTe has long been regarded as one promising choice for the development of cost-effective and reliable solar cells. Efficiency as high as 16.5% has been achieved in CdS/CdTe heterojunction structure in laboratory in 2001, and current techniques for CdS/CdTe solar cells gradually step toward commercialization. This paper reviews some novel techniques mainly within two years to solve this problem from aspects of promotion of fabrication technology, structural modification, and choice of back contact materials.
Ethnicity and Race Variations in Receipt of Surgery among Veterans with and without Depression
Authors: Copeland Laurel A. , Zeber John E. , Pugh Mary Jo , Phillips Karon L. , Lawrence Valerie A.
Published: October 2011

To examine equity in one aspect of care provision in the Veterans Health Administration, this study analyzed factors associated with receipt of coronary artery bypass graft (CABG), vascular, hip/knee, or digestive system surgeries during FY2006–2009. A random sample of patients (N=317,072) included 9% with depression, 17% African-American patients, 5% Hispanics, and 5% women. In the four-year followup, 18,334 patients (6%) experienced surgery: 3,109 hip/knee, 3,755 digestive, 1,899 CABG, and 11,330 vascular operations. Patients with preexisting depression were less likely to have surgery than nondepressed patients (4% versus 6%). In covariate-adjusted analyses, minority patients were slightly less likely to receive vascular operations compared to white patients (HispanicOR=0.88,P<.01; African-AmericanOR=0.93,P<.01) but more likely to undergo digestive system procedures. Some race-/ethnicity-related disparities of care for cardiovascular disease may persist for veterans using the VHA.
Prevalence of and Barriers to Dual-Contraceptive Methods Use among Married Men and Women Living with HIV in India
Authors: Chakrapani Venkatesan , Kershaw Trace , Shunmugam Murali , Newman Peter A. , Cornman Deborah H. , Dubrow Robert
Published: October 2011

Objective. To describe the prevalence and correlates of dual-contraceptive methods use (condomsandaneffectivepregnancy prevention method) and barriers to their use among married persons living with HIV (PLHIV) in India.Methods. We conducted a quantitative survey (93 men, 97 women), 25 in-depth interviews, seven focus groups, and five key informant interviews.Results. Prevalence of dual- contraceptive method use increased from 5% before HIV diagnosis to 23% after diagnosis (P < 0.001). Condoms were the most common contraceptive method, with prevalence increasing from 13% before diagnosis to 92% after diagnosis (P < 0.001). Barriers to using noncondom contraceptives were lack of discussion about noncondom contraceptives by health care providers, lack of acceptability of noncondom contraceptives among PLHIV, and lack of involvement of husbands in family planning counseling.Conclusion. There is a need for interventions, including training of health care providers, to increase dual-contraceptive methods use among married PLHIV.
Streptococcus thermophilus ST28 Ameliorates Colitis in Mice Partially by Suppression of Inflammatory Th17 Cells
Authors: Ogita Tasuku , Nakashima Megumi , Morita Hidetoshi , Saito Yasuo , Suzuki Takuya , Tanabe Soichi
Published: October 2011

The effects of Streptococcus thermophilus ST28 on cytokine production by murine splenocytes stimulated with transforming growth factor‐β plus interleukin‐ (IL‐) 6 were evaluated. The addition of ST28 significantly repressed IL‐17 production compared to ATCC 19258 (type strain). ST28 also decreased the number of Th17 cells in the stimulated splenocytes. The anti‐inflammatory effects of ST28 administration were evaluated in mice with colitis induced by dextran sodium sulphate (DSS). Oral treatment of mice with ST28 ameliorated the intestinal lesions by DSS. Upon DSS treatment, IL‐17 production in lamina propria lymphocytes (LPLs) was induced, but ST28 significantly decreased its production. ST28 also decreased the percentage of Th17 cells in LPL from DSS‐induced colitis. The present results imply that ST28 suppresses the Th17 response in inflamed intestines and would be useful in the treatment of Th17‐mediated diseases, such as inflammatory bowel disease.