bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the Impact of Efalizumab on Nail, Scalp and Palmoplantar Psoriasis and on Quality of Life: Results from a Multicentre, Open‐label, Phase IIIb/IV Trial
Authors: Katsambas Andreas , Peris Ketty , Vena Gino , Freidmann Peter , Wozel Gottfried , Daudén Esteban , Licu Daiana , Placchi Mauro , De La Brassinne Michel
Published: November 2009

This post‐approval, open‐label trial (n = 1266) assessed the efficacy of efalizumab, administered in accordance with the European label at that time, in patients with concomitant nail, scalp or palmoplantar psoriasis. Patients received subcutaneous efalizumab 1.0 mg/kg weekly for up to 20 weeks. By Week 12, an improvement from baseline of 50% or more was observed in 21.4% (181/844) of patients with nail psoriasis, 62.4% (718/1150) of patients with scalp psoriasis, and 51.4% (127/247) of patients with palmoplantar psoriasis. Quality of life improved throughout the trial, with a 50% median improvement in DLQI score after 12 weeks of treatment. Efalizumab showed promising efficacy in the treatment of nail, scalp and palmoplantar psoriasis, which was reflected in improvements in quality of life.
Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP): 24‐month experience with telemedicine screening
Authors: Murakami Yohko , Silva Ruwan A. , Jain Atul , Lad Eleonora M. , Gandhi Jarel , Moshfeghi Darius M.
Published: November 2009

Purpose:  To report the 24‐month experience of the Stanford University Network for Diagnosis of Retinopathy of Prematurity (SUNDROP) telemedicine initiative.

Methods:  Retrospective analysis of the SUNDROP archival data gathered between 1 December 2005 and 30 November 2007 to evaluate this diagnostic technology for ROP screening. One hundred and sixty consecutively enrolled infants meeting ROP examination criteria were screened with the RetCam II and evaluated by the SUNDROP reading centre at Stanford University. Nurses obtained five or six images in each eye. All patients also received a dilated examination within 1 week of discharge. Outcomes included treatment‐warranted retinopathy of prematurity (TW‐ROP) and anatomical outcomes.

Results:  In the initial 24‐month period, the SUNDROP telemedicine initiative has not missed any TW‐ROP. A total of 160 infants (320 eyes) were imaged, resulting in 669 exams and 7556 images. Seven infants were identified with TW‐ROP; six underwent laser photocoagulation and one regressed spontaneously. The sensitivity was 100%, with specificity of 99.4%. No patient progressed to retinal detachment or other adverse outcomes.

Conclusion:  The SUNDROP telemedicine screening initiative for ROP has been proven to have a high degree of sensitivity and specificity for the identification of treatment‐warranted disease. All cases of treatment‐warranted disease were captured. There were no adverse outcomes.
Homeland and Belonging among Cubans in Spain
Authors: Berg Mette Louise
Published: November 2009

Este artículo contribuye a los debates recientes en estudios de diáspora sobre la relación entre procesos de exclusión, experiencias de desplazamiento y memorias de país de origen existentes en la producción de subjetividades diaspóricas. El artículo concierne a la diáspora cubana en España, la cual consiste de aproximadamente 50,000 personas. Estas personas representan refutadas prácticas y discursos sobre origen y desplazamiento, sobre pertenecer y no pertenecer. En este artículo sostengo que la noción de “generación diaspórica” nos puede ayudar a entender los modos contrastantes en que los cubanos habitan diáspora. Las generaciones diaspóricas se basan en trayectorias de migración. Éstas ponen los aspectos temporales de la formación de la diáspora en primer plano y por encima de aspectos espaciales. Sostengo que para las dos generaciones más recientes de esta diáspora, prácticas y discursos de exclusión tanto en el país de origen como en el lugar de la diáspora igual que entre la primera generación de la diáspora han contribuido en la producción de subjetividades desterritorializadas.

This article is a contribution to recent debates within diaspora studies of the relationship between processes of exclusion, experiences of displacement, and memories of homeland in the production of diasporic subjectivities. It concerns the Cuban diaspora in Spain, consisting of approximately 50,000 people who represent contesting practices and discourses of home and away, belonging and not‐belonging. In the article I argue that to understand diasporic Cubans' contrastive modes of inhabiting Diaspora, the notion of “diasporic generations” is helpful. Diasporic generations are based on trajectories of migration, thus foregrounding the temporal aspects of Diaspora formation over spatial aspects. I argue that among the two most recent generations of this Diaspora, practices and discourses of exclusion in both homeland and diasporic location as well as among the first generation of the diaspora have led to the production of deterritorialized subjectivities.
Some Factors Influencing the Contact Behavior of Surfaces
Authors: Nuri K. A.
Published: November 2009

The contact behavior of metal surfaces has been studied by determining the normal approach of two contacting surfaces subjected to a normal load. By considering certain contact situations, the effects of such factors as the mode of asperity deformation, the population of asperities and their orientation over the surface have been examined. It has been demonstrated that the contact behavior is significantly influenced by these factors and that certain modifications should be introduced to the relevant theoretical treatment.
The Analysis and Performance of Pivoted Pad Journal Bearings Considering Thermal and Elastic Effects
Authors: Ettles C. M. McC.
Published: November 2009

A large number of variables are associated with the design of pivoted pad bearings that makes a generalised approach using charts most difficult. All design offices now have readily available on-line computer terminals that have access to library programs. The development of a library program for this type of bearing is described and discussed. The analysis considers the entire bearing as opposed to the superposition of results of individual pads. This simplifies the solution of the temperature field for each pad and allows the inclusion of turbulence, hot oil carry over and thermal and elastic distortion of each pad. The analysis is verified against three sets of independent experimental results. It is shown that the effect of pad bending is to lower the bearing damping so that the unbalance response is increased.
The Hollow Roller Bearing
Authors: Bowen W. L. , Bhateja C. P.
Published: November 2009

The paper deals with the unique functional characteristics that the use of hollow rolling elements induce in a radial type cylindrical roller bearing. The ability to consistently and successfully preload these hollow rollers between the inner and the outer races together with, of course, the necessary but usual degree of precision of the bearing components, provides an effective control of the shaft run-out. This makes the bearing especially suitable for high precision applications. The roller preloading also eliminates the need for a roller guidance from a retainer which, combined with the lighter rollers, generally means higher speed capabilities. In addition to the inherent superior rotational accuracy of the hollow roller bearing, it is also demonstrated as to why, contrary to the common belief, the preloading ability of the hollow rollers results in significant stiffness improvements over, say, a corresponding solid roller bearing. The significance of the roller hollowness is discussed with regard to the stiffness, load capacity and life characteristics of this bearing. Finally, the suitability of the various lubrication systems for this bearing are discussed.
Some Observations on the Relationship Between Lubricant Mechanical and Dielectric Transitions Under Pressure
Authors: Bair S. , Winer W. O.
Published: November 2009

Viscoelastic transition measurements of several lubricants by volume dilatometry to pressures of 1.75 GPa, dielectric transitions at atmospheric pressure on five fluids in a frequency range of 0.2 to 500 kHz and on two fluids in the same frequency range to pressures of 0.55 GPa are reported. Lines of constant rate dilatometry transition, constant rate dielectric transition and constant viscosity are shown to be essentially parallel on a temperature-pressure diagram.
Phase Change in Liquid Face Seals II—Isothermal and Adiabatic Bounds With Real Fluids
Authors: Hughes W. F. , Chao N. H.
Published: November 2009

Phase change effects in parallel and tapered liquid face seals are studied analytically. Both an isothermal and adiabatic model of low Reynolds number flow are considered by numerical integration of the descriptive equations for a real fluid. Real fluid thermodynamic properties are calculated for each step, using a computer program for the steam tables or thermodynamic properties of the fluid considered. Examples are presented for water. The general conclusions are: 1. For low leakage rate the isothermal model is more accurate and for high leakage rates the adiabatic model is more accurate. 2. Both parallel models, ordinarily neutrally stable with a liquid, yield the same general conclusions about stability. If the sealed fluid is near enough to saturation conditions, there will exist generally two values of the film gap, h, which yield the same separating force under a given set of operating conditions. For a given speed, face excursions about the larger value are stable, but excursions about the lower value are unstable, either growing to the larger h if displaced apart or collapsing if displaced together. 3. The transient of collapse is described by the adiabatic model which predicts a catastrophic collapse and then either failure or explosive return to a larger value of h. 4. Converging seals (ordinarily stable with a liquid at some given value of h) may become unstable, the phase change effect dominating the behavior and giving rise to collapse as described above. 5. The mass leakage rate is reduced significantly below the all liquid value when boiling occurs.
High Speed Cylindrical Rolling Element Bearing Analysis “CYBEAN”—Analytic Formulation
Authors: Kleckner R. J. , Pirvics J. , Castelli V.
Published: November 2009

This paper documents the analytic foundation and software architecture for the computerized mathematical simulation of high speed cylindrical rolling element bearing behavior. The software, CYBEAN (CYlindrical BEaring ANalysis), considers a flexible, variable geometry outer ring, EHD films, roller centrifugal and quasidynamic loads, roller tilt and skew, mounting fits, cage and flange interactions. The representation includes both steady state and time transient simulation of thermal interactions internal to and coupled with the surroundings of the bearing. A sample problem illustrating program use is presented.
The Pearson System of Distributions: Its Application to Non-Gaussian Surface Metrology and a Simple Wear Model
Authors: Spedding T. A. , King T. G. , Watson W. , Stout K. J.
Published: November 2009

The height distributions of surface profiles generated by some engineering production processes are discussed, and it is shown that they may usually be modelled by continuous distributions from the Pearson system. A simple profile truncation model for wear is proposed based upon previous experimental results. This model is applied to a number of Pearson distributions to predict post-wear surface finish parameters for initially non-Gaussian surfaces.
Optimal Mechanism Design Using the Gauss Constrained Method
Authors: Paradis M. J. , Willmert K. D.
Published: November 2009

Presented in this paper is an optimization technique for solving problems with objective functions which are sums of squared quantities with linear constraints. The technique is based on Gauss’ unconstrained method, but is able to move along constraint surfaces in such a way that when the technique terminates, the Kuhn-Tucker conditions are satisfied. The resulting approach, called the Gauss constrained method, is shown to be very efficient and effective in solving problems with highly nonlinear objective functions often existing in mechanism design problems.
Optimal Design of Tanker’s Pump and Piping Systems
Authors: Akagi S. , Ito K.
Published: November 2009

A computer-aided planning method is proposed to design pump and piping systems used for the tanker’s oil unloading process. The following two planning models are combined hierarchically for the purpose of investigating a system’s multiple design objectives simultaneously: (a) A multiobjective nonlinear optimal planning model is developed to determine the set of Pareto optimal solutions concerning pipe diameters and the pump head. In this model, the following two mutually conflicting and noncommensurable objective functions are minimized—the total piping system’s size, and the pump size. (b) A simulation model is developed to check the dynamic behavior of the oil unloading process, and the real unloading time is calculated together with oil level differences among tanks. The validity and effectiveness of the design method proposed here is ascertained through the numerical calculation for a real existing tanker’s pump and piping system.
Coverless Containers Using a Minimum of Plate Material
Authors: Spotts M. F.
Published: November 2009

This paper presents the optimization of a bin or tank that does not require a cover. A worthwhile saving of plate material for a given volume can be made by giving an outward flare to the sides. Another advantage is that the increased width at the top permits greater heaping of dry materials like coal or gravel. There is also a decreased possibility of spillage.
The Stability of the Motion of a Connecting Rod
Authors: Zhu Z. G. , Chen Y.
Published: November 2009

This paper presents the results of the investigation concerning the stability of the motion of a connecting rod. For simplicity in analysis, the rod is assumed to have a constant cross-sectional area. In the analysis a perturbation method was used, based on the assumption that the ratio of crank radius to the rod length is a small parameter. The successive approximations to the transverse motion of the rod satisfying the Mathieu-type of partial differential equations, from which expressions for instability regions of motion were derived. Numerical method was used in calculating several cases of the transverse vibrational response, both stable and unstable.
Synthesis of Bimodal Function Generating Mechanisms Without Branch Defect
Authors: Gupta K. C. , Tinubu S. O.
Published: November 2009

A theory is proposed for the synthesis of bimodal function generators which are free from the branch defect. It is applicable to planar as well as spatial linkages. Precision type synthesis has been considered for planar four-bar and spatial R-S-S-R linkages. Applications of the theory are illustrated by means of numerical examples.
An Experimental and Analytical Investigation of the Dynamic Response of a High-Speed Cam-Follower System. Part 2: A Combined, Lumped/Distributed Parameter Dynamic Model
Authors: Pisano A. P. , Freudenstein F.
Published: November 2009

Part 2 describes the development of a dynamic model of a high-speed cam-follower system in which the return spring is modeled as a distributed-parameter element. The dynamic response requires the solution of a coupled set of differential equations, one ordinary and one partial. The dynamic model has the unique capability of faithfully reproducing the effect of the higher harmonics of the cam lift curve on system performance. The model, which has been refined and verified with the aid of the results described in Part 1, is capable of accurately predicting both normal system response as well as pathological behavior associated with the onset of toss, bounce, and spring surge. In comparison, a lumped-parameter dynamic model (differing only in the modeling of the valve spring) does not adequately predict the onset of pathological behavior.
Into Mesh Lubrication of Spur Gears With Arbitrary Offset Oil Jet. Part 1: For Jet Velocity Less Than or Equal to Gear Velocity
Authors: Akin L. S. , Townsend D. P.
Published: November 2009

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or less than pitch line velocity. The analysis includes the case for the oil jet offset from the pitch point in the direction of the pinion and where the oil jet is inclined to intersect the common pitch point. Equations were developed for the minimum oil jet velocity required to impinge on the pinion or gear and the optimum oil jet velocity to obtain the maximum impingement depth. The optimum operating condition for best lubrication and cooling is provided when the oil jet velocity is equal to the gear pitch line velocity with both sides of the gear tooth cooled. When the jet velocity is reduced from pitch line velocity the drive side of the pinion and the unloaded side of the gear is cooled. When the jet velocity is much lower than the pitch line velocity the impingement depth is very small and may completely miss the pinion.
Computer-Aided Design of a Punch Assembly
Authors: Nguyen D. , Kaftanoglu B.
Published: November 2009

In the high-speed page printing systems used as peripherals to computers, the paper moves at a speed of around 30 in./s. The printing and punching of the paper has to be done when the paper is in motion. If the punching is not finished in a short enough time, the paper would get torn up by the punchette. In a typical punch assembly as used in modern page printing systems, a plunger is driven forward by the force of a solenoid. Plunger impacts the punchette which in turn punches a hole in the paper which is in motion. To minimize the flight time of the punchette with the object of increasing paper speed, the design parameters of the punch assembly must be carefully selected. In this paper, a model for the punch assembly is developed. The necessary equations for plunger and punchette motion are derived. The design parameters, such as the masses of the plunger and punchette, constants for springs used in the assembly, force generated by the solenoid, and the gap between the plunger and punchette, are varied using a Rosenbrock algorithm to minimize the flight time of the punchette. The results obtained indicate that by the use of a Computer-Aided Design approach optimal values of design parameters can be found before the development of prototypes and experiments.
Synthesis of Conjugated Surfaces for Sealing Systems
Authors: Litvin F. L. , Hukvari I. S. , Krueger J. E.
Published: November 2009

Sealing systems consisting of stationary seat and rotating seal surfaces are considered. The seal and seat surfaces may be in surface contact or in line contact. The geometry of different types of seal-seat surfaces is discussed: (a) with surface contact between conical and spherical surfaces and surfaces of revolution, (b) with line contact of a surface of revolution and a conical surface. A new method for synthesis of conjugated surfaces for sealing systems is proposed. The method is based on specific applications of the general theory of enveloped surfaces. Seal and seat surfaces synthesized by this method are in surface or line contact at the closed position and do not interfere with each other at any open position. Relations between design parameters of sealing systems to meet these requirements are developed. The method presented uses general assumptions and can be applied for various types of seal-seat surfaces. Examples of synthesis of seal-seat surfaces are provided.
The Undercutting of Hobbed Spur Gear Teeth
Authors: Mitchiner R. G. , Mabie H. H. , Moosavi-Rad H.
Published: November 2009

A general method is presented for the determination of the minimum number of teeth that can be cut in a spur gear without undercutting by a rounded-tooth tip hob. The minimum number of teeth to produce undercutting was investigated for three trochoid/tooth-profile relations: (1) trochoid tangent to the involute profile at the base circle, (2) trochoid tangent to a straight portion of the tooth flank, and (3) trochoid intersecting the involute profile at the base circle. It was found that in order to avoid undercutting, the minimum number of teeth cut into a gear occurs when the trochoid is tangent to the involute at the base circle. There is no set of hob parameters such that the trochoid intersects the involute profile at the base circle nor does the case of the trochoid being tangent to a straight flank exist. A set of figures representing the variation of the amount of undercutting versus the number of teeth, radius of hob-tooth tip, hob addendum, cutting pressure angle, and the corresponding derivatives are included for a typical gear.
Analysis of Road Induced Loads in Bicycle Frames
Authors: Wong M. G. , Hull M. L.
Published: November 2009

A five degree-of-freedom model of a bicycle and rider was developed to investigate the system response to inputs from the road as the first step in a unique fatigue failure analysis of a bicycle frame. Transfer functions relating the induced frame loads and the road input spectra are given, as are the frame load spectra for realistic levels of road inputs. The transfer functions show that the system is lightly damped and responds more strongly to inputs at the rear wheel than to inputs at the front. The load spectra show that the load picture is one of small fluctuations around a relatively large static offset.
Some Kinematic Structures for Robot Manipulator Designs
Authors: Earl C. F. , Rooney J.
Published: November 2009

Some kinematic structures suitable for use in robot manipulator designs are constructed in terms of components. General properties of kinematic structures are considered and a method for combining two structures given. Two types of component, namely actuation and distribution components, are specified. Modification of the kinematic structures is effected by transfer of drives. Existing designs for robot manipulators are examined in terms of their kinematic structures and some new designs are generated.
Kinematic and Force Analysis of Articulated Mechanical Hands
Authors: Salisbury J. K. , Roth B.
Published: November 2009

This paper deals with several of the basic concepts in the kinematics of mechanical hands. Several different types of finger contacts are modeled and used in a number synthesis of three-fingered hands. Screw theory is used to show which finger configurations allow complete immobilization of the gripped object relative to the fingers, and also allow for the manipulation of the object by the fingers while maintaining the grasp. Shown in this paper is how to determine the forces applied by the fingers on the object, and also how to compute the velocities of the fingers and the object. The analysis developed in this paper is shown to lead to a hand with three fingers, each with three turning joints, and having friction contacts with an object at three separate points.
On the Dynamic Analysis and Behavior of Industrial Robotic Manipulators With Elastic Members
Authors: Sunada W. H. , Dubowsky S.
Published: November 2009

This paper presents a method for analyzing the complete behavior of industrial robotic manipulators with complex-shape flexible links, including the effects of the manipulator’s control systems and actuators. The kinematics and dynamics of the manipulator are expressed in terms of 4 × 4 matrices. The distributed flexibility and mass properties of the links are obtained by using readily available finite-element models and programs. The resulting equations are transformed to produce a method which is computationally efficient through a procedure called Component Mode Synthesis. The method is applied to an actual industrial manipulator and the results are compared to experimental data, showing good correlation. Link flexibility is demonstrated to have significant impact on system performance and stability.
An Algorithm for the Workspace of a General n-R Robot
Authors: Tsai Y. C. , Soni A. H.
Published: November 2009

An algorithm is developed to determine the workspace on an arbitrary plane for an n-R robot. The algorithm is based on a linear optimization technique and on small incremental displacements applied to coordinate transformation equations relating the kinematic parameters of the n-R robot. The algorithm provides flexibility to let the user treat the robot hand as a point, a line, or a rigid-body. The revolute pairs of the robot may execute full or partial rotation. The proposed method may be extended to incorporate in a robot the existence of prismatic pairs along with revolute pairs.
Connectivity-Three Mechanical Couplings and the Algebraic Complexes They Trace
Authors: Fichter E. F.
Published: November 2009

The subject of this paper is the degree of the algebraic line complexes traced by mechanisms consisting of three connectivity-1 couplings arranged in series. A theorem which gives the degree is presented and proved. The theorem is applied to the eight mechanisms consisting only of single kinematic pairs (revolute and prismatic). In the discussions of some of these mechanisms the degree is determined independently of the proof of the theorem. The theorem is also applied to the mechanisms of some commercial robotic manipulators.
On the Workspace of Mechanical Manipulators
Authors: Yang D. C. H. , Lee T. W.
Published: November 2009

This paper presents an analytical investigation of manipulator workspace. The first part presents the derivation of a set of recursive equations in terms of motion and design parameters representing the workspace. These formulas are basic for the determination of the characteristics as well as the shape of workspace. The remainder of the paper concerns the investigation of the existence of hole and void in workspace. A set of criteria is formulated. Algorithms for implementing these criteria are developed. Manipulators with both unlimited and limited revolute joints are studied in this investigation.
On the Evaluation of Manipulator Workspace
Authors: Lee T. W. , Yang D. C. H.
Published: November 2009

This paper presents a theorem regarding manipulator workspace and, based on this theorem, a manipulator performance index is introduced. It is found that for a given manipulator structure the ratio of the volume of the workspace to the cube of its total link length is a constant. Algorithms for outlining the boundary profile of workspace and for quantitative evaluation of its volume are presented. A computer package, KAM, is developed, which implements the theories and algorithms developed in this investigation as well as in a companion paper [1]. Several specific examples are given to illustrate the application of the performance index and the capability of KAM.
Kinematic Precision of Gear Trains
Authors: Litvin F. L. , Goldrich R. N. , Coy J. J. , Zaretsky E. V.
Published: November 2009

Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. This paper explains a general method for the determination of kinematic precision of gear trains. The general method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general and approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular-arc (Wildhaber-Novikov) gears, and spiral-bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory.
Effect of Internal Material Damping on the Dynamics of a Slider-Crank Mechanism
Authors: Badlani M. , Midha A.
Published: November 2009

A study of the effect of internal material damping on the dynamic response behavior of a slider-crank mechanism is presented in this paper. In developing the governing equations of motion, an assumption of a linear viscoelastic model for the connecting rod is made. A perturbation approach is utilized for reducing these coupled axial and transverse nonlinear equations to a nonhomogeneous damped Mathieu equation, describing the transverse vibration of the connecting rod. Both steady-state and transient solutions are determined and compared to those obtained from the use of an undamped connecting rod. It is demonstrated that the viscoelastic material damping can have significant influence, both favorable and adverse, in attempting to attenuate the steady-state and transient response of the connecting rod. The response is computed for several combinations of the excitation parameter and the frequency ratio. The stability of the transverse vibration of the connecting rod is also investigated in this paper.
Dynamics of Planar, Elastic, High-Speed Mechanisms Considering Three-Dimensional Offset Geometry: Analytical and Experimental Investigations
Authors: Stamps F. R. , Bagci C.
Published: November 2009

Mechanisms in industrial applications in general operate as three-dimensional elastic systems, including planar mechanisms due to offsets between the planes of motion of links. This article investigates dynamic behaviors of planar mechanisms with offset geometry analytically and experimentally for dynamic stress and critical speed levels. Three-dimensional line element with irregular freedoms is used and generalized digital computer programs are prepared to perform kineto-elasto-static, dynamic stress, frequency, and critical speed analyses of three-dimensional mechanisms including the planar mechanisms with three-dimensional offsets. An experimental planar four-bar mechanism was tested for critical speed and elastodynamic stress levels with three levels of offsets. It has been determined that a mechanism experiences integer divisions of the integrated average of the three-dimensional fundamental natural frequency, ωinavg, within a cycle of the mechanism as critical speeds as well as its multiples. Recommended operating speeds of a mechanism are those in between two integer divisions of ωinavg at lower levels. Elastodynamic stress levels at these recommended speed levels are predicted analytically by kineto-elasto-static analysis and very conservatively even in the shock loading zones of the mechanism. The validity of the highly economical CGKES (Critical Geometry Kineto-Elasto-Statics) method for mechanisms having three-dimensional geometry is also verified by the experimental results.
On the Dynamics of Intermittent-Motion Mechanisms. Part 2: Geneva Mechanisms, Ratchets, and Escapements
Authors: Wang A. C. , Lee T. W.
Published: November 2009

The theory developed in Part 1 has been applied to the determination of the dynamic response of three typical types of intermittent-motion mechanisms, namely, Geneva mechanisms, ratchets, and escapements. Insight into the behavior of such mechanisms can be obtained by studying the characteristics of the mathematical model and by numerical experiments. The results, whenever possible, are illustrated by computer-plotted graphs. A comparative study with some limited current investigations on the same subject is provided.
Application of Optimal Control Theory to the Synthesis of High-Speed Cam-Follower Systems. Part 1: Optimality Criterion
Authors: Chew M. , Freudenstein F. , Longman R. W.
Published: November 2009

The synthesis of the parameters governing the dynamic response of high-speed cam-follower systems ideally involves an integrated approach capable of carrying out the tradeoffs necessary to achieve optimum dynamic response in the design stage. These trade-offs involve a balance between the system characteristics at the output and at the cam-follower interface. In this investigation optimal-control theory has been demonstrated to be a useful tool in developing such a tradeoff. Part 1 describes the development of an optimization criterion while Part 2 describes the application of optimal-control theory to the evaluation of system parameters satisfying the optimization criterion.
A Bivariate Normal Model of Mechanism Coupler-Point Position
Authors: Schade G. R.
Published: November 2009

A bivariate normal model of the coupler-point position of a four-bar linkage is presented. Elliptical confidence regions are established as a function of the statistical properties of the mechanism component dimensions. A measure of mechanism merit based on the probability of deviation from mean path is developed. The probabilistic models are verified by Monte Carlo techniques.
Three-Dimensional Multiple Scattering of Elastic Waves by Spherical Inclusions
Authors: Liu Zunping , Cai Liang-Wu
Published: November 2009

This paper extends the scatterer polymerization methodology to three-dimensional multiple scattering of elastic waves by spherical inclusions. The methodology was originally developed for analyzing multiple scattering of elastic antiplane shear waves in two-dimensional spaces. The analytically exact solution of multiple scattering is reformulated by using this methodology, which is verified by using different ways, with or without scatterer polymerization, to solve physically the same multiple scattering problem. As an application example, the band gap formation for elastic wave propagating in a cubic lattice of spherical scatterers is observed through a series of numerical simulations. These simulations also demonstrate the capability of the present computational system for simulating three-dimensional multiple scattering of elastic waves.
Defect Diagnosis for Rolling Element Bearings Using Acoustic Emission
Authors: He Yongyong , Zhang Xinming , Friswell Michael I.
Published: November 2009

Rolling element bearings are very common components in rotating machinery. Hence, condition monitoring and the detection of defects are very important for the normal and safe running of these machines. Vibration based techniques are well established for the condition monitoring of rolling element bearings, although they are not so effective in detecting incipient defects in the bearing. Acoustic emission (AE) is receiving increasing attention as a complementary method for condition monitoring of bearings as AE is very sensitive to incipient defects. This paper presents an experimental study to investigate the AE characteristics of bearing defect and validates the relationship between various AE parameters and the operational condition of rolling element bearings. To analyze the characteristic vibration frequency of the bearing using the AE signal, short-time rms and autocorrelation functions are integrated to extract the actual characteristic frequency. The AE signal is then analyzed using standard parameters of the signals to explore the source characteristics and sensitivity of typical rolling element bearing faults. The results demonstrate that the proposed method is very effective to extract the actual characteristic frequency of the bearing by AE signal. Furthermore the AE parameters are always sensitive to the running and fault conditions, which have a strong influence on the strain and deformation within the bearing material.
High Symbiont Relatedness Stabilizes Mutualistic Cooperation in Fungus-Growing Termites
Authors: Aanen Duur K. , de Fine Licht Henrik H. , Debets Alfons J. M. , Kerstes Niels A. G. , Hoekstra Rolf F. , Boomsma Jacobus J.
Published: November 2009

Gardening for Ants and Termites

Among the social insects, ants and termites are the most diverse and ecologically dominant. Termites are known to engage in a mutualism with nitrogen-fixing bacteria, and

Pinto-Tomás
et al.

(p.
1120
) have identified similar relationships occurring among leaf-cutter ants, which maintain specialized nitrogen-fixing bacteria in their fungus gardens. Together, these mutualisms are a major source of nitrogen in terrestrial ecosystems. How is the evolutionary stability of such mutualistic cooperation maintained?

Aanen
et al.

(p.
1103
) show that the
Termitomyces
fungus cultured by termites remains highly related because mycelia of the same clone fuse together and grow more efficiently to out-compete rare clones.
The Palomero Genome Suggests Metal Effects on Domestication
Authors: Vielle-Calzada Jean-Philippe , Martínez de la Vega Octavio , Hernández-Guzmán Gustavo , Ibarra-Laclette Enrique , Alvarez-Mejía Cesar , Vega-Arreguín Julio C. , Jiménez-Moraila Beatriz , Fernández-Cortés Araceli , Corona-Armenta Guillermo , Herrera-Estrella Luis , Herrera-Estrella Alfredo
Published: November 2009

A-Maize-ing

Maize is one of our oldest and most important crops, having been domesticated approximately 9000 years ago in central Mexico.

Schnable
et al.

(p.
1112
; see the cover) present the results of sequencing the B73 inbred maize line. The findings elucidate how maize became diploid after an ancestral doubling of its chromosomes and reveals transposable element movement and activity and recombination.

Vielle-Calzada
et al.

(p.
1078
) have sequenced the
Palomero Toluqueño
(
Palomero
) landrace, a highland popcorn from Mexico, which, when compared to the B73 line, reveals multiple loci impacted by domestication.

Swanson-Wagner
et al.

(p.
1118
) exploit possession of the genome to analyze expression differences occurring between lines. The identification of single nucleotide polymorphisms and copy number variations among lines was used by

Gore
et al.

(p.
1115
) to generate a Haplotype map of maize. While chromosomal diversity in maize is high, it is likely that recombination is the major force affecting the levels of heterozygosity in maize. The availability of the maize genome will help to guide future agricultural and biofuel applications (see the Perspective by

Feuillet and Eversole

).
Direct Imaging of Bridged Twin Protoplanetary Disks in a Young Multiple Star
Authors: Mayama Satoshi , Tamura Motohide , Hanawa Tomoyuki , Matsumoto Tomoaki , Ishii Miki , Pyo Tae-Soo , Suto Hiroshi , Naoi Takahiro , Kudo Tomoyuki , Hashimoto Jun , Nishiyama Shogo , Kuzuhara Masayuki , Hayashi Masahiko
Published: November 2009

Planetary Midwifery

Planets form from the materials left behind after a star is formed. Unlike the Sun, most stars are members of binary systems.

Mayama
et al.

(p.
306
, published online 19 November) present an infrared image of the protoplanetary disks around a young binary star system taken with the coronagraph mounted on the Subaru Telescope in Hawaii. Each individual disk is clearly visible around its star, and comparison with numerical simulations suggests that there could be gas flow from one disk to the other. The nature of this potential gas flow is important in determining where planets could form in binary systems.
Gigahertz Dynamics of a Strongly Driven Single Quantum Spin
Authors: Fuchs G. D. , Dobrovitski V. V. , Toyli D. M. , Heremans F. J. , Awschalom D. D.
Published: November 2009

Quick Spin Flips

Quantum computation holds the tantalizing promise of vastly improving the efficiency of traditional computers. Among the many solid-state candidates for storing and manipulating quantum information, nitrogen vacancy centers in diamond are especially attractive because they can be used at room temperature and stay operational for milliseconds at a time. To use this coherence time efficiently, it is important to achieve fast manipulation of the spins in the system.

Fuchs
et al.

(p.
1520
, published online 19 November; see the Perspective by

Gerardot and Öhberg

) used pulses of strong microwave magnetic field to probe the dynamics of single spins in a nitrogen vacancy center. In this “strong-driving” nonlinear regime, extremely quick spin flips of less than a nanosecond in duration were observed, offering the possibility that up to a million operations could be performed on a single spin during its coherence time.
Hydrate Molecular Ballet
Authors: Debenedetti Pablo G. , Sarupria Sapna
Published: November 2009

An exceptionally long computer simulation offers a glimpse of molecular events leading to methane hydrate formation.
Solving the Maze
Authors: Feuillet Catherine , Eversole Kellye
Published: November 2009

The maize genome sequence will allow further analyses of genetic diversity and the genetic basis for traits critical to plant breeding.
Belt-Tightening Could Claim Some Scientific Scalps
Authors: Normile Dennis
Published: November 2009

Attempting to rein in Japan's yawning budget deficit, a government task force last week recommended tens of millions of dollars in cuts in science spending in the fiscal year beginning next April that would hit everything from research grants to big-ticket items such as a next-generation supercomputer.
Steak With a Side of Beta-Glucans
Authors: Pennisi Elizabeth
Published: November 2009

At the 9th International Plant Molecular Biology Congress, researchers described progress in manipulating the beta-glucan content of grains and other plant tissues, which could boost the fiber content of foods and enhance the value of the currently unusable parts of corn and wheat for biofuels.
Disease-related expression of the IL6/STAT3/SOCS3 signalling pathway in ulcerative colitis and ulcerative colitis-related carcinogenesis
Authors: Li Yi , de Haar Colin , Chen Min , Deuring Jasper , Gerrits Monique M , Smits Ron , Xia Bing , Kuipers Ernst J , van der Woude C Janneke
Published: November 2009

Background

Mouse models have shown that interleukin (IL)6 stimulates survival, proliferation and progression to cancer of intestinal epithelial cells via activation of signal transducers and activators of transcription 3 (STAT3).

Objective

To investigate the expression of IL6/phosphorylated STAT3 (p-STAT3)/suppressor of cytokine signalling 3 (SOCS3) in biopsy specimens from patients with ulcerative colitis (UC) and UC-related colorectal cancer (CRC) progression.

Methods

Biopsy specimens from patients with inactive UC (n=18), active UC (n=28), UC with low-grade dysplasia (LGD) (n=9), UC with high-grade dysplasia (HGD) (n=7), UC-CRC (n=11) and sporadic CRC (n=14) were included. Biopsy specimens (n=9) from patients without colonic abnormalities served as control. The protein expression of IL6, p-STAT3 and SOCS3 was determined immunohistochemically.

Results

Patients with active UC had significantly more IL6 and p-STAT3-positive epithelial cells than both patients with inactive UC and controls (strong positive IL6: 53.6%, 11.1% and 0%, respectively; p-STAT3: 64.3%, 22.2% and 11.1%, respectively; all p≤0.012). SOCS3-positive cells were significantly increased in colonic epithelium of both inactive and active UC compared with controls (strong positive: 94.4%, 96.4% and 11.1%, respectively; both p<0.001). In dysplasia and cancer, significantly more epithelial cells expressed IL6 and p-STAT3 compared with controls (strong positive IL6: 72.7% and 0% respectively; p-STAT3: 54.5% and 11.1%, respectively; both p<0.05), whereas the proportion of SOCS3-positive cells in this progression reduced (LGD 33.3%; HGD 14.3%; UC-CRC 9.1%). In addition, methylation of the SOCS3 gene was detected in epithelial cells from UC-CRC biopsy specimens.

Conclusion

The importance of IL6/p-STAT3 in patients with inflammation-induced CRC was demonstrated. Moreover, SOCS3 may be involved in UC pathogenesis and the absence of SOCS3 seems critical for CRC progression.
Seston Ecology of the Surface Waters of Hudson Bay
Authors: Anderson J. T. , Roff J. C.
Published: November 2009

The planktonic biomass variables, chlorophyll a, ATP, particulate organic carbon, and nitrogen have been measured in surface waters throughout Hudson Bay for the first time. On the basis of these variables Hudson Bay can be regarded as oligotrophc during the summer months. Clear inshore–offshore gradients of biomass were evident showing significant correlations in transects to salinity, temperature, depth, and distance from shore. Chlorophyll a values were always low, averaging 0.09 mg m−3 offshore and 0.28 mg m−3 inshore. ATP averaged 0.072 mg m−3 offshore and twice as high inshore. Biomass ratios also demonstrated clear inshore–offshore gradients; carbon:nitrogen ratios ranged from 4.9:1 inshore to 12.5:1 offshore indicating nitrogen limitation of offshore waters. Chlorophyll a: phaeopigment ratios decreased and biocarbon:chlorophyll a ratios increased offshore indicating an increased proportion of heterotrophs and possibly higher relative grazing pressure offshore. For the inshore areas, biomass and probably productivity were highest and significantly correlated to runoff with the exception of the Southampton–Coats–Mansel islands area, which is influenced by waters from Foxe Channel and Hudson Strait. While Hudson Bay meets most of the criteria for arctic classification, its character is sufficiently different to warrant special status.Key words: Hudson Bay, seston ecology, chlorophyll a, biomass ratios, phaeopigments, plankton
Comparison of Two Methods of Estimating the Variance of the Estimate of Catch Per Unit Effort
Authors: Smith S. J.
Published: November 2009

Two methods of estimating the variance of the estimate of catch per unit effort are compared empirically here. The second method, an application of the Jackknife estimator proved to be the overall best technique due to its generality. In addition the Jackknife method provides means for the estimation of confidence intervals.Key words: catch per unit effort, variance estimation, Jackknife estimator
Morphological Changes in Gill Epithelia of Heat-Stressed Rainbow Trout, Salmo gairdneri: Evidence in Support of a Temperature-Induced Surface Area Change Hypothesis
Authors: Jacobs Dan , Esmond Edward F. , Melisky Edward L. , Hocutt Charles H.
Published: November 2009

Surface morphology of the gill structure of hatchery-reared rainbow trout (Salmo gairdneri) exposed to heat shock was examined by scanning electron microscopy. Changes were greatest in fish previously acclimated to 6 °C and exposed to 24 or 30 °C water for 3–5 d. Gill epithelia of heat-stressed fish showed a reduction and loss of the microridge patterns. The surface of the efferent arterial sides of the primary lamellae became irregular and rugose, and fusion of the secondary lamellae occurred at higher temperatures. The morphological changes along with an increase in mucus production may be a major factor in causing hypoxia in heat-stressed fish.Key words: gill epithelium, rainbow trout, primary lamellae, secondary lamellae, temperature, heat stress, scanning electron microscopy
Selection of External Tags for Marking Atlantic Herring (Clupea harengus harengus)
Authors: Nakashima Brian S. , Winters G. H.
Published: November 2009

Of seven external tags (carlin, disc and disc, disc and dangler, anchor, short anchor, dart, streamer) applied to Atlantic herring (Clupea harengus harengus), the anchor tag is the best to use when tagging rate, recovery rate, and persistence of tagged fish in the population are considered. A high recovery rate for carlin tags was more than compensated by the higher application rate exhibited by anchor and dart tags. Anchor tagged fish had a lower sustained mortality and reduced time in setting up the tags for application compared to dart tags. Tagged herring suffered higher short and apparent long-term mortalities than the unmarked population regardless of which external tag type was applied. Long-term tag loss may have been due to tag induced mortality and/or tag shedding. Consequently, studies requiring data beyond 2 yr after release would need another type of tag. Initial mortalities of herring increased with holding and handling time for all tags tested. This result confirms that herring should be tagged immediately after capture to reduce initial mortalities.