bluuebunny/crossref_metadata_2025 huggingface dataset:
Beyond Pull-In Stabilization of Dual Axis Micromirrors Using Fuzzy Controllers
Authors: Moeenfard Hamid , Ahmadian Mohammad Taghi , Soroush Ali , Alasty Aria
Published: March 2011

Dual axis micromirrors are actuated using strongly nonlinear electrostatic actuation and their operating range suffers from the pull-in problem. So investigation of their dynamics and control issues has become a challenge for the researchers. The current paper makes use of fuzzy controllers for the purpose of stabilizing the dual axis micromirror at the desired tilt angles beyond pull-in. At first the dynamic model of the micromirror is presented. Then for the purpose of finding the linguistic laws governing the system behavior, several step voltages are introduced to the system. The proposed fuzzy controller consists of singleton fuzzifier, product inference engine and center average defuzzifier. It was observed from the simulation results that the presented controller can effectively and immediately stabilize and control the micromirror tilt angles beyond pull-in, with a short rise time and also a short overshoot.
Designing Energy Harvesting Skin Structure Utilizing Outdoor Unit Vibration
Authors: Lee Soobum , Youn Byeng D. , Giraud Matthieu
Published: March 2011

This paper presents a new energy harvesting (EH) concept design, referred to as EH skin structure. A generic design and experimental verification methodology will be proposed to demonstrate the feasibility of the EH skin for practical applications. In the past, EH researches have primarily focused on designing a device-level energy harvester, such as a cantilever-type EH device. However, such a device-level energy harvester has several drawbacks: (i) need of an extra space for proof masses and fixture, (ii) significant energy loss due to the fixture, and (iii) need of a casing for EH device protection against environmental harms. While this new EH concept design could overcome the drawbacks above, there is no design methodology for EH skin. This paper proposes design and experimental verification methodology for EH skin structure. The design methodology comprises three tasks: (i) construction of a valid computational model, (ii) design optimization of EH skin, and (iii) experimental verification. An outdoor condensing unit of which a fan produces harmonic vibration is chosen for a case study because similar configuration of vibration can be found in many engineered systems (e.g., airplane wing, AC unit). The proposed design methodology determined an optimal EH skin configuration (sizes, locations, etc.) on the vibrating structure. The EH skin was carefully prototyped to demonstrate that it can generate power up to 3.7mW, which is sustainable for operating wireless sensor units for structural health monitoring or building automation.
A Generic Sensor Network Design Framework Based on a Detectability Measure
Authors: Wang Pingfeng , Youn Byeng D. , Hu Chao
Published: March 2011

Significant technological advances in sensing and communication promote the use of large sensor networks to monitor structural systems, identify damages, and quantify damage levels. Prognostics and health management (PHM) technique has been developed and applied for a variety of safety-critical engineering structures, given the critical needs of the structure health state awareness. The PHM performance highly relies on real-time sensory signals which convey the structural health relevant information. Designing an optimal structural sensor network (SN) with high detectability is thus of great importance to the PHM performance. This paper proposes a generic SN design framework using a detectability measure while accounting for uncertainties in material properties and geometric tolerances. Detectability is defined to quantify the performance of a given SN. Then, detectability analysis will be developed based on structural simulations and health state classification. Finally, the generic SN design framework can be formulated as a mixed integer nonlinear programming (MINLP) using the detectability measure and genetic algorithms (GAs) will be employed to solve the SN design optimization problem. A power transformer study will be used to demonstrate the feasibility of the proposed generic SN design methodology.
Ensemble of Data-Driven Prognostic Algorithms With Weight Optimization and K-Fold Cross Validation
Authors: Hu Chao , Youn Byeng D. , Wang Pingfeng
Published: March 2011

The traditional data-driven prognostic approach is to construct multiple candidate algorithms using a training data set, evaluate their respective performance using a testing data set, and select the one with the best performance while discarding all the others. This approach has three shortcomings: (i) the selected standalone algorithm may not be robust, i.e., it may be less accurate when the real data acquired after the deployment differs from the testing data; (ii) it wastes the resources for constructing the algorithms that are discarded in the deployment; (iii) it requires the testing data in addition to the training data, which increases the overall expenses for the algorithm selection. To overcome these drawbacks, this paper proposes an ensemble data-driven prognostic approach which combines multiple member algorithms with a weighted-sum formulation. Three weighting schemes, namely, the accuracy-based weighting, diversity-based weighting and optimization-based weighting, are proposed to determine the weights of member algorithms for data-driven prognostics. The k-fold cross validation (CV) is employed to estimate the prediction error required by the weighting schemes. Two case studies were employed to demonstrate the effectiveness of the proposed prognostic approach. The results suggest that the ensemble approach with any weighting scheme gives more accurate RUL predictions compared to any sole algorithm and that the optimization-based weighting scheme gives the best overall performance among the three weighting schemes.
Hue Assisted Registration of 3D Point Clouds
Authors: Men Hao , Pochiraju Kishore
Published: March 2011

This paper presents a variant of the Iterative Closest Point (ICP) algorithm for merging multiple color point clouds generated from a mobile 3D Light Detection and Ranging (LIDAR) System. This algorithm uses hue information generated from a camera along with the coordinates of the scan points and enables high accuracy registration of point clouds. A k-d tree based nearest neighbor search associates corresponding colored points in 4-D space between data and model point clouds. Singular Value Decomposition (SVD) method solves for the rigid rotation and translation. Experimental results illustrate that 3D color point clouds accelerate the 3D map registration if the hue data and model point clouds have sufficient hue distribution and the imaging sensor robustly captures the hue.
Application of Time-Increasing Internal Pressure in Vibration Reduction of Viscoelastic Rotary Beams
Authors: Younesian Davood , Esmailzadeh Ebrahim
Published: March 2011

Vibration suppression of a viscoelastic rotary beam using time–increasing internal pressure is presented in this paper. Coupled nonlinear longitudinal/bending vibration of a beam is assumed and, the governing equations of motion are derived for a rotating beam with time–varying internal pressure. Numerical simulations are carried out for various increasing profiles of the internal pressure and efficiency of the proposed suppression technique is evaluated in free and forced vibration. Resonant harmonic excitations as well as the broadband random excitations are also taken into account and performance of the control system is investigated. Application of the suppression system is also studied in case of angular decelerating rotary beams in which softening behavior occurs due to decreasing centrifugal force.
Configuration Synthesis of Metamorphic Mechanisms Based on Characteristic Incidence Matrix
Authors: Li Duanling , Zhang Zhonghai , Dai Jian S. , McCarthy J. Michael
Published: March 2011

This paper presents an approach to the configuration synthesis of metamorphic mechanisms with consideration of both link and joint changes. The technique, referred to here as computational geometry, uses a constraint graph to represent topological structure of metamorphic mechanisms instead of traditional graph representation that can not distinguish link types and multi-joints. Based on the constraint graph, a characteristic incidence matrix is proposed with the characteristic relationships between links and joints. Then, a synthetic method based on characteristic incidence matrix is put forward in this paper using operations among matrixes with different orders by binary computing. Through an example of a four-bar mechanism synthesizing into five-bar mechanisms with the proposed configuration synthetic method, it is confirmed that the approach is correct and effective for the configuration synthesis of all metamorphic mechanisms with single or multiple joints.
Shilnikov Type Multi-Pulse Orbits of Functionally Graded Materials Rectangular Plate
Authors: Zhang Wei , Yao Ming-Hui , Cao Dong-Xing
Published: March 2011

Multi-pulse chaotic dynamics of a simply supported functionally graded materials (FGMs) rectangular plate is investigated in this paper. The FGMs rectangular plate is subjected to the transversal and in-plane excitations. The properties of material are graded in the direction of thickness. Based on Reddy’s third-order shear deformation plate theory, the nonlinear governing equations of motion for the FGMs plate are derived by using the Hamilton’s principle. The four-dimensional averaged equation under the case of 1:2 internal resonance, primary parametric resonance and 1/2-subharmonic resonance is obtained by directly using the asymptotic perturbation method and Galerkin approach to the partial differential governing equation of motion for the FGMs rectangular plate. The system is transformed to the averaged equation. From the averaged equation, the theory of normal form is used to find the explicit formulas of normal form. Based on normal form obtained, the energy phase method is utilized to analyze the multi-pulse global bifurcations and chaotic dynamics for the FGMs rectangular plate. The analysis of global dynamics indicates that there exist the multi-pulse jumping orbits in the perturbed phase space of the averaged equation. From the averaged equations obtained, the chaotic motions and the Shilnikov type multi-pulse orbits of the FGMs rectangular plate are found by using numerical simulation. The results obtained above mean the existence of the chaos for the Smale horseshoe sense for the simply supported FGMs rectangular plate.
A Cutting Plane Method for Analytical Target Cascading With Augmented Lagrangian Coordination
Authors: Wang Wenshan , Blouin Vincent Y. , Gardenghi Melissa , Wiecek Margaret M. , Fadel Georges M. , Sloop Benjamin
Published: March 2011

Various decomposition and coordination methodologies for solving large-scale system design problems have been developed and studied during the past few decades. However, there is generally no guarantee that they will converge to the expected optimum design under general assumptions. Those with proven convergence often have restricted hypotheses or a prohibitive cost related to the required computational effort. Therefore there is still a need for improved, mathematically grounded, decomposition and coordination techniques that will achieve convergence while remaining robust, flexible and easy to implement. In recent years, classical Lagrangian and augmented Lagrangian methods have received renewed interest when applied to decomposed design problems. Some methods are implemented using a subgradient optimization algorithm whose performance is highly dependent on the type of dual update of the iterative process. This paper reports on the implementation of a cutting plane approach in conjunction with Lagrangian coordination and the comparison of its performance with other subgradient update methods. The method is demonstrated on design problems that are decomposable according to the analytic target cascading (ATC) scheme.
Nonlinear Dynamics of Granular Chains
Authors: Starosvetsky Yuli , Vakakis Alexander F.
Published: March 2011

We study strongly nonlinear traveling waves in one-dimensional granular chains with no pre-compression. We directly study the discrete, strongly nonlinear governing equations of motion of these media without resorting to continuum approximations or homogenization, which enables us to compute families of stable multi-hump traveling wave solutions with arbitrary wavelengths. We develop systematic semi–analytical approaches for computing different families of nonlinear traveling waves parametrized by spatial periodicity (wavenumber) and energy. Our findings indicate that homogeneous granular chains possess complex nonlinear dynamics, including the capacity for intrinsic nonlinear energy transfer.
Robotic Project-Based Pre-Training for In-Coming Undergraduate Mechanical Engineering Students
Authors: Tang Chin Pei , Goeckner Matthew , Spong Mark W.
Published: March 2011

This paper describes the pre-training approach using research projects to get the in-coming mechanical engineering undergraduate student jump started for their four years of college career. We used a robotics research project to go through the full engineering design lifecycle, including (a) brain-storming, (b) feasibility studies, (c) building simple models for evaluation, and (d) engineering/construction. With the help of the mentors, the approach has effectively involved the students to identify potential problems and solve them effectively during the execution of the projects. The resulting constructed robotic delivery truck is a mathematically interesting problem that will be solved as a research problem.
Using Symbol Emergence to Discover Multi-Lingual Translations in Design
Authors: Mukerjee Amitabha , Dabbeeru Madan Mohan
Published: March 2011

Incorporating design knowledge into computational design requires “symbols” — but this term as used in knowledge-based models of design is a formal term, defined only in terms of other symbols. For most humans, symbols are [term : meaning] pairs that emerge while interacting with real designs. However, both the term and its interpretation vary considerably across design groups, particularly in today’s international cooperative design scenario. For translating symbols in design, one needs to incorporate the design context, which is since the actual design object and its characteristics form the most relevant part of the context. In this work, we consider an embodied symbols approach towards translation, where models corresponding to symbol semantics are discovered based on functional norms in a given design context. The functions are available as performance measures on a given task, and lead to low-dimensional characterizations (called image schema) that reveal inter-relations in the input space that must hold for functional validity. Some of these image schemas eventually acquire language labels and become symbols. Since different designers differ in experience and in language their symbols differ somewhat. Here we consider how independent language agents may map these low-dimensional characterizations (called chunks) to units of languages based on human commentary produced in the same context. We demonstrate how this process may work for the simple domain of insertion tasks and fits, and learn both the image schemas and the language labels in two different languages, English and Telugu.
Multifrequency Approaches in Characterization of Materials With Single-Pass Kelvin Force Microscopy
Authors: Magonov Sergei , Alexander John D.
Published: March 2011

This article presents an implementation of high-resolution imaging in Kelvin force microscopy (KFM) using the multi-frequency approach in the intermittent contact mode. The basic function of atomic force microscopy – high resolution imaging of surface topography is usually performed in the resonant oscillatory modes: amplitude modulation or frequency modulation. When a conducting probe is applied in the AFM-related electric modes it senses also the electrostatic tip-sample forces. Simultaneous and separate detection of the mechanical and electrostatic forces can be realized by using the probe response at different resonant and non-resonant frequencies. In KFM, a nullification of the electrostatic force is applied for detection of a local surface potential. The described experimental set-up and procedures help us to reveal the surface potential variations with high sensitivity and spatial resolution. The examples of KFM studies of metals, semiconductors and molecular systems with dipole moments demonstrate how this technique can be applied for advanced and quantitative characterization of heterogeneous systems.
Rapidly Charging Battery Systems
Authors: Rodgers Lennon , Karplus Paul , Gogoana Radu , Nawrot Mike
Published: March 2011

For rapidly charging battery systems to be fully realized, there must be [i] a cell chemistry with an adequate energy density that accepts high power charging without overheating and accelerated degradation, [ii] electricity sources that can supply the necessary charging power, [iii] battery pack designs that can handle the large charging currents while not drastically decreasing the mass and volumetric energy densities, and [iv] high power chargers. This study first explores the feasibility of these elements, and presents a particular design that was demonstrated on an electric motorcycle. The final system consists of four battery modules, totaling 1.6 kWatt-hours, a 10 kWatt charger, and an integrated circuit-based Battery Management System. A single module was rapidly charged to 90% capacity in 15 minutes, and all four modules connected in series were rapidly charged to 40% capacity. Future tests will rapidly charge the 4 modules to >90% capacity.
Type Synthesis of Parallel Mechanisms Having Two Rotations
Authors: Gao Feng , Yang Jialun , Ge Qiaode Jeffrey
Published: March 2011

In the last few decades, researchers have proposed a few different methods to synthesize parallel mechanisms. In this paper, we propose both the natural law for kinematic mobility and the generalized function sets (GF set for short) which are used for the type synthesis of parallel mechanisms, particularly for those having two rotations. The natural law for kinematic mobility lays the foundation for the algorithms of the intersection of GF sets. Moreover, the GF sets are used for describing the performance criteria of the end-effectors of robotic manipulators in a clear and systematic way, including the mechanisms having two rotations. Finally, several novel parallel mechanisms having two rotations have been illustrated to show the effectiveness of the proposed methodology.
Spatial Difference of Two-Point Resolution and Apparent Movement Characteristics of Vibratory Tactile Stimulation
Authors: Nishimura Kanako , Ikei Yasushi
Published: March 2011

This paper describes two evaluations of pin-density characteristics of vibratory tactile stimulation for display design. First, the two-point threshold of vibratory pin stimulation was measured in terms of the position within a fingerpad to optimize vibratory pin layout that is appropriate for high perception ratio with fewer number of pins. The two-point threshold exhibited quite different values depending on the point within the fingerpad. The spatial resolution was higher at the distal side than the proximal side. Second, an apparent movement was measured under two conditions—twelve stimulators with a 1.5-mm inter-pin distance and six stimulators with a 3.0-mm distance on the surface of a fingerpad. The result suggested that the 1.5-mm condition produced the sensation of apparent movement more intensely and clearly in a wider range of inter stimulus onset interval.
Engine Oil Condition Monitoring Using High Temperature Integrated Ultrasonic Transducers
Authors: Kobayashi M. , Sun Z. , Jen C.-K. , Wu K.-T. , Bird J. , Galeote B. , Mrad N.
Published: March 2011

High temperature integrated ultrasonic transducers (IUTs) made of thick piezoelectric composite films have been coated directly onto the lubricant oil supply and sump lines of a modified CF700 turbojet engine. These thick piezoelectric films are fabricated using a sol-gel spray technology. The center frequencies of these IUTs are in the range of 10 to 12 MHz. The top electrodes, electrical wires, conducting adhesive bond, connectors and cables have been tested successfully for temperatures of up to 500°C. By operating these IUT in transmission mode, the amplitude and velocity of transmitted ultrasonic waves across the flow channel of the lubricant oil in supply and sump lines were measured during engine operation. The results have shown that the strength of the ultrasonic waves is sensitive to the presence of air bubbles in the oil and that the ultrasound velocity is linearly dependent on oil temperature. Based on the sensitivity of ultrasound velocity to oil temperature, a method for real-time monitoring of engine oil degradation is proposed.
The Influence of Post Angioplasty Stent Implant Profile on Arterial Wall Stress
Authors: Teodorescu Mircea , Brand Moshe , Rosen Jacob , Rahnejat Homer
Published: March 2011

One of the main causes for post angioplasty arterial restenosis is the excessive stress induced in the arterial wall during and after the medical intervention. The closed stent is introduced in the artery wrapped around the deflated balloon catheter and is expanded in the final position by inflating the balloon. Unfortunately, this process also stretches the arterial wall. Additionally, for the stent to be successful, its diameter must be slightly larger than the diameter of the inflated artery. The stent is usually a dense mesh of interconnected beams. Therefore, it is often considered that it applies a constant pressure to the artery / stent interface. However, in reality each beam individually presses against the innermost layer of the artery (intima). The current study proposes a model, which predicts the arterial wall subsurface stress field due to individual stent beams. It was found that the local shape of the contact (beam cross section) plays an important role close to the stent / intima contact. Sharper edged cross sections (e.g. square) promote higher stresses. It was observed that during restenosis a new inner layer (neointima) is formed, significantly reducing the stent efficiency. This could be related to local stress concentrations due to the choice of stent beam profile.
Adaptive Bayesian Methods in Manufacturing Process Control With Small Experimental Data Sets
Authors: Vanli O. Arda
Published: March 2011

In capital intensive manufacturing processes the amount of experimental data available may not be adequate to build a sufficiently accurate statistical model. This paper presents a new Bayesian predictive approach for sequential experimentation that aims to combine experimentation and optimization stages. A dual control approach that simultaneously considers model estimation and process optimization objectives is adopted. By combining these two goals the objective is to more quickly start production with little or no historical data from the process.
Microstructure evolution of Ti3SiC2 compound cathodes during reactive cathodic arc evaporation
Authors: Zhu J. Q. , Eriksson A. O. , Ghafoor N. , Johansson M. P. , Greczynski G. , Hultman L. , Rosén J. , Odén M.
Published: March 2011

The microstructure evolution and compositional variation of Ti3SiC2 cathode surfaces during reactive cathodic arc evaporation are presented for different process conditions. The results show that phase decomposition takes place in the near-surface region, resulting in a 5–50 μm thick converted layer that is affected by the presence of nitrogen in the deposition chamber. This layer consists of two different sublayers, i.e., 1–20 μm thick top layer with a melted and resolidified microstructure, followed by a 4–30 μm thick transition layer with a decomposed microstructure. The converted layer contains a polycrystalline TiCx phase and trace quantities of Si-rich domains with Ti5Si3(C) at their interface. The arc discharge causes Si redistribution in the two regions of the layer, whose Si/(Ti+Si) ratio is higher in the top region and lower in the transition region compared to the virgin material.
Compensation of space charge for positive ion beams using electron injection and confinement in nonuniform magnetic fields
Authors: Nicolaescu Dan , Sakai Shigeki , Gotoh Yasuhito , Ishikawa Junzo
Published: March 2011

Transportation of a low energy ion beam, as required by advanced implantation systems, is difficult due to space charge that makes the beam to diverge. Compensation of space charge may be obtained through electron injection and confinement. The article presents the computer simulated results obtained with the OPERA3D/TOSCA/SCALA commercial software package. It has been shown that electrons injected in the regions of nonuniform magnetic fields around dipoles and other magnets that are used for ion beam control exhibit helical trajectories which can be confined inside curved “magnetic bottles.” An optimal range of positions for placing electron sources with respect to the magnet has been shown to exist.
Breast Cancer Methylomes Establish an Epigenomic Foundation for Metastasis
Authors: Fang Fang , Turcan Sevin , Rimner Andreas , Kaufman Andrew , Giri Dilip , Morris Luc G. T. , Shen Ronglai , Seshan Venkatraman , Mo Qianxing , Heguy Adriana , Baylin Stephen B. , Ahuja Nita , Viale Agnes , Massague Joan , Norton Larry , Vahdat Linda T. , Moynahan Mary Ellen , Chan Timothy A.
Published: March 2011

Breast cancer methylomes contribute to metastatic potential, modulate the metastasis transcriptome, and predict disease outcome.
Genotypic and Histological Evolution of Lung Cancers Acquiring Resistance to EGFR Inhibitors
Authors: Sequist Lecia V. , Waltman Belinda A. , Dias-Santagata Dora , Digumarthy Subba , Turke Alexa B. , Fidias Panos , Bergethon Kristin , Shaw Alice T. , Gettinger Scott , Cosper Arjola K. , Akhavanfard Sara , Heist Rebecca S. , Temel Jennifer , Christensen James G. , Wain John C. , Lynch Thomas J. , Vernovsky Kathy , Mark Eugene J. , Lanuti Michael , Iafrate A. John , Mino-Kenudson Mari , Engelman Jeffrey A.
Published: March 2011

Lung cancers undergo dynamic genetic and histological changes upon developing resistance to EGFR inhibitors.
Calvin Cycle Flux, Pathway Constraints, and Substrate Oxidation State Together Determine the H
2
Biofuel Yield in Photoheterotrophic Bacteria
Authors: McKinlay James B. , Harwood Caroline S.
Published: March 2011

Hydrogen gas (H
2
) is a possible future transportation fuel that can be produced by anoxygenic phototrophic bacteria via nitrogenase. The electrons for H
2
are usually derived from organic compounds. Thus, one would expect more H
2
to be produced when anoxygenic phototrophs are supplied with increasingly reduced (electron-rich) organic compounds. However, the H
2
yield does not always differ according to the substrate oxidation state. To understand other factors that influence the H
2
yield, we determined metabolic fluxes in
Rhodopseudomonas palustris
grown on
13
C-labeled fumarate, succinate, acetate, and butyrate (in order from most oxidized to most reduced). The flux maps revealed that the H
2
yield was influenced by two main factors in addition to substrate oxidation state. The first factor was the route that a substrate took to biosynthetic precursors. For example, succinate took a different route to acetyl-coenzyme A (CoA) than acetate. As a result,
R. palustris
generated similar amounts of reducing equivalents and similar amounts of H
2
from both succinate and acetate, even though succinate is more oxidized than acetate. The second factor affecting the H
2
yield was the amount of Calvin cycle flux competing for electrons. When nitrogenase was active, electrons were diverted away from the Calvin cycle towards H
2
, but to various extents, depending on the substrate. When Calvin cycle flux was blocked, the H
2
yield increased during growth on all substrates. In general, this increase in H
2
yield could be predicted from the initial Calvin cycle flux.

IMPORTANCE
Photoheterotrophic bacteria, like
Rhodopseudomonas palustris
, obtain energy from light and carbon from organic compounds during anaerobic growth. Cells can naturally produce the biofuel H
2
as a way of disposing of excess electrons. Unexpectedly, feeding cells organic compounds with more electrons does not necessarily result in more H
2
. Despite repeated observations over the last 40 years, the reasons for this discrepancy have remained unclear. In this paper, we identified two metabolic factors that influence the H
2
yield, (i) the route taken to make biosynthetic precursors and (ii) the amount of CO
2
-fixing Calvin cycle flux that competes against H
2
production for electrons. We show that the H
2
yield can be improved on all substrates by using a strain that is incapable of Calvin cycle flux. We also contributed quantitative knowledge to the long-standing question of why photoheterotrophs must produce H
2
or fix CO
2
even on relatively oxidized substrates.
Compliance with physical activity guidelines in rural, black South Africans in the Limpopo Province: an energy expenditure approach
Authors: Cook Ian , Alberts Marianne , Lambert Estelle V
Published: March 2011

Objective

The authors used an energy expenditure–based approach to determine the non-compliance and compliance with public health physical activity (PA) guidelines in rural, black South Africans.

Methods

The authors analysed 7-day objectively measured PA data (NL-2000 pedometer) in 508 females and 267 males. Compliance was defined for the American College of Sports Medicine guideline (ACSM: ≥7.5 to <21 kcal/kg/week and ≥1.5 kcal/kg/day for ≥5 days/week) and the Institute of Medicine guideline (IOM: ≥21 kcal/kg/week and ≥3 kcal/kg/day for 7 days/week).

Results

The age- and sex-adjusted prevalence for non-compliance, ACSM compliance and IOM compliance in the sample was 7.8%, 55.0% and 37.2%, respectively. Complying with IOM guidelines required substantially more ambulation (14 522 steps/day) than ACSM guidelines (10 837 steps/day) and non-compliance (6420 steps/day) (p<0.0001). Approximately 95% of IOM-compliant subjects and 51% of ACSM-compliant subjects achieved ≥10 000 steps/day on 4–7 days. Compliance with IOM or ACSM guideline was associated with an 87% (p<0.0001) and a 49% (p=0.0647) reduced risk of obesity, respectively. Partial and full IOM compliance was associated with a significantly reduced risk of obesity (OR=0.58 to 0.16, p<0.04).

Conclusions

The 10 000 steps/day guideline concurs with the ACSM guideline, whereas IOM compliance required higher ambulation levels. Compared with ACSM compliance, IOM compliance was associated with a lower risk of obesity.
Paraoxonase-1 and oxidative status in common Mediterranean β-thalassaemia mutations trait, and their relations to atherosclerosis
Authors: Labib Hany A , Etewa Rasha Lotfi , Gaber Osama A , Atfy Maha , Mostafa Tamer M , Barsoum Ihab
Published: March 2011

Aims

Investigation of paraoxonase-1 (PON1) activity with oxidative status parameters and the increased susceptibility to atherogenesis in β-thalassaemia-trait (BTT) subjects.

Methods

Sixty BTT subjects and 20 age- and sex-matched healthy controls were enrolled in the study. Serum PON1, total antioxidant capacity (TAC), malondialdehyde (MDA) and carotid artery intima-media thickness (CIMT) were determined. Qualitative detection of β-thalassaemia mutations was carried out.

Results

Serum PON1 activity and TAC were significantly lower in BTT subjects than in controls (p<0.001), while MDA and CIMT were significantly higher (p<0.001). In BTT subjects, TAC, MDA, and CIMT levels were significantly correlated with serum PON1 (r=0.945, −0.900, 0.940 and −0.922 respectively). Serum TAC and MDA were significantly correlated (r=–0.979).

Conclusions

Oxidative stress is increased, while serum PON1 activity is decreased in BTT subjects. Decrease in PON1 activity is associated with the degree of oxidative stress, anaemia and increase in CIMT. Therefore, BTT subjects may be more prone to development of atherosclerosis.
Regional disparities in compliance with tobacco control policy in Japan: an ecological analysis
Authors: Yorifuji Takashi , Tanihara Shinichi , Takao Soshi , Kawachi Ichiro
Published: March 2011

Background

The slow progress of tobacco control policy in Japan reflects the tension among the interests of the Finance Ministry (which remains the majority shareholder of Japan Tobacco, Inc), the Health Ministry, tobacco growers and consumers.

Methods

We sought to examine regional disparities in compliance with national tobacco control legislation (the 2003 Health Promotion Law). Specifically, we sought to examine whether prefecture-level compliance with legislation was correlated with decreases in smoking prevalence, and decreases in lung cancer mortality rates. We also examined whether prefectural involvement in growing tobacco was associated with lower compliance with the law.

Results

From 2001 to 2007, higher prefectural compliance with tobacco control laws was associated with decreased prevalence of smoking. Decreased tobacco consumption was in turn associated with declining lung cancer mortality. Prefectures involved in growing tobacco exhibited lower levels of compliance with national tobacco control laws. The same prefectures also exhibited the worst improvement in smoking prevalence.

Conclusions

This study in Japan suggests that tobacco control policies are being unevenly implemented across prefectures, and that measures to counteract the influence of local tobacco culture are required to reduce the disparities in regional tobacco control outcomes in that country.
ANALYSIS OF THE CLOSED CRITICAL LOOPS IN THE PHASE DIAGRAMS FOR A BINARY GAS–LIQUID MIXTURE USING A MODIFIED LATTICE-GAS MODEL
Authors: GENÇASLAN MUSTAFA , YILMAZ YEŞIM , YILMAZ AHMET
Published: March 2011

The critical lines of the binary fluid system may, under certain circumstances, exhibit closed loops in the critical lines. We give some of the necessary requirements for this phenomenon. A distinction is made between free critical loops, as described by type VI in the Scott and van Konynenburg classification, and "rooted" critical loops, as found in the shield region. We define rooted loops as closed critical lines that are attached to the critical line structure by means of an unstable critical line. A general theory is given for the first and the second type is illustrated with the results obtained from the modified lattice-gas model. This modification is known as the Tompa model, which was introduced to describe a compressible polymer–solvent system. It is shown how the appearance of a stable branch detached from the rest of the critical line structure in density space gives rise to a segment in pressure temperature space. Finally, we show how the position of these rooted critical loops can be found by algebraic means.
Influence of Post-Welding Heat Treatment on the Corrosion Behavior of a 2050-T3 Aluminum-Copper-Lithium Alloy Friction Stir Welding Joint
Authors: Proton Vincent , Alexis Joël , Andrieu Eric , Blanc Christine , Delfosse Jérôme , Lacroix Loïc , Odemer Grégory
Published: March 2011

The corrosion behavior of a Friction Stir Welding joint in 2050-T3 Al-Cu-Li alloy was studied in 1 M NaCl solution and the influence of T8 post-welding heat treatment on its corrosion susceptibility was analyzed. After exposure to 1 M NaCl solution, the heat affected zone (HAZ) of the weld without post-welding heat treatment was found to be the most extensively corroded zone with extended intergranular corrosion damage while, following T8 post-welding heat treatment, no intergranular corrosion was observed in the HAZ and the global corrosion behavior of the weld was significantly improved. The corrosion damage observed on the welded joints after immersion in 1 M NaCl solution was compared to that obtained after 750 h Mastmaasis Wet Bottom tests. The same corrosion damage was observed. Various stationary electrochemical tests were carried out on the global welded joint and/or each of the metallurgical zones of the welded joint to understand the corrosion damage observed. TEM observations helped in bringing meaningful elements to analyze the intrinsic electrochemical behavior of the different zones of the weld related to their microstructure. However, galvanic coupling tests showed that galvanic coupling effects between the different zones of the weld were at least partially responsible for its corrosion behavior.
The Phenomenological Account for Electronic Polarization in Ionic Liquid
Authors: Chaban Vitaly , Voroshylova Iuliia V. , Kalugin Oleg
Published: March 2011

Although a great variety of classical force fields (FFs) for room-temperature ionic liquids (RTILs) have been recently suggested, no systematically derived non-polarizable model is able to reproduce their transport properties, i.e. diffusion constants, conductivities and viscosities. In the present paper, we show that modern FFs greatly overestimate pairwise electrostatic interaction energies in the RTILs systems leading to extremely hindered ionic motions. Based on the results of our ab initio molecular dynamics calculations using explicit ionic environment, we modified the electrostatic interaction potential of 1-ethyl-3-methylimidazolium tetrafluoroborate. Starting from FF, originally derived by Liu et al., we further refined it, so that it reproduces experimental transport properties without compromizing either structure or thermodynamics. The main advantages of the suggested phenomenological account for electronic polarization are its consistency, clearness, simplicity and the possibility to improve functionality of the existing FFs by modifying exclusively atomic partial electrostatic charges.
A "Looking Glass" into Electrolyte Properties: Acetonitrile-Lithium Salt (AN-LiX) Mixtures
Authors: Seo Daniel M. , Han Sang-Don , Ly Quang , Henderson W. A.
Published: March 2011

Phase diagrams have been prepared for acetonitrile mixtures with either LiBF4 or LiClO4. Crystalline solvate structures were determined to complement the phase diagrams and provide additional insight into variations in Li+ cation coordination in the solid-state. This information has then been utilized to aid in understanding the solvation and ionic association of Li+ cations in the liquid-state.
Quantum Chemistry Studies of the Oxidative Stability of Carbonate, Sulfone and Sulfonate-Based Electrolytes Doped with BF4
-, PF6
- Anions
Authors: Borodin Oleg , Jow T. R.
Published: March 2011

Quantum chemistry studies of the oxidative stability of carbonate, sulfonate and sulfone-based solvents with and without BF4-, PF6- anions were performed using M05-2X Minnesota density functional and cc-pvTz basis set. Presence of BF4- and PF6- anions was found to significantly decrease oxidative stability of a number of carbonate solvents such as ethylene carbonate, dimethyl carbonate and propylene carbonate via HF formation. Oxidation of the tetramethyl sulfone/BF4- and propargyl methanesulfonate/PF6- complexes resulted in the fluorine transfer to the solvent. Oxidation of the tetramethyl sulfone/BF4- complex also resulted in a spontaneous ring opening. No water was needed to form PF5 and BF3 upon oxidation of the solvent/BF4- and solvent/PF6- complexes. Density functional estimates of the solvent/anion oxidative stability were found in good agreement with available experimental data for non-active electrodes after polarized continuum model was utilized to implicitly account for the surrounding solvent dielectric permittivity.
Cathode Solid Electrolyte Interphase Generation in Lithium-Ion Batteries with Electrolyte Additives
Authors: Markmaitree Tippawan , Yang Li , Lucht Brett
Published: March 2011

The incorporation of additives designed to sacrificially react on the surface of cathode materials of lithium ion batteries has been investigated. Addition of low concentrations of either organic (2,5-dihydrofuran (2,5-DHF) or γ-butyrolactone (GBL)) or inorganic additives (lithium bisoxalatoborate (LiBOB), lithium difluorooxalatoborate (LiBF2(C2O4)), tetramethoxytitanium (TMTi), and tetraethoxysilane (TEOS)) to 1 M LiPF6 in 1:1:1 EC/DEC/DMC improves the capacity retention of Li/ Li1.17Mn0.58Ni0.25O2 cells cycled to 4.9 V vs Li.
Electrochemical Characterization of SEI-Type Passivating Films Using Redox Shuttles
Authors: Tang Maureen , Newman John
Published: March 2011

Although redox shuttles have been demonstrated to provide overcharge protection for up to 200 cycles, the existence of the solid-electrolyte-interphase (SEI), a passivating film on the negative electrode, seems to be inherently incompatible with a successful shuttle reaction. In this work, the kinetics of ferrocene is measured in the presence and absence of passivating films using rotating-disk-electrode voltammetry. The steady-state current-voltage curve is described by a simple model of Butler-Volmer kinetics and a through-film limiting current. The presence of a passivating film decreases both the limiting current and the effective rate constant. Both parameters decrease with increased passivation time; a decreasing porosity is a possible explanation for the latter observation. The characterization method developed in this work allows direct measurements of the effect of passivating films, thus contributing to understanding of passivation phenomena in nonaqueous electrolytes.
Increased energy expenditure and leptin sensitivity account for low fat mass in myostatin-deficient mice
Authors: Choi Sun Ju , Yablonka-Reuveni Zipora , Kaiyala Karl J. , Ogimoto Kayoko , Schwartz Michael W. , Wisse Brent E.
Published: March 2011

Myostatin deficiency causes dramatically increased skeletal muscle mass and reduced fat mass. Previously, myostatin-deficient mice were reported to have unexpectedly low total energy expenditure (EE) after normalizing to body mass, and thus, a metabolic cause for low fat mass was discounted. To clarify how myostatin deficiency affects the control of body fat mass and energy balance, we compared rates of oxygen consumption, body composition, and food intake in young myostatin-deficient mice relative to wild-type (WT) and heterozygous (HET) controls. We report that after adjusting for total body mass using regression analysis, young myostatin-deficient mice display significantly increased EE relative to both WT (+0.81 ± 0.28 kcal/day, P = 0.004) and HET controls (+0.92 ± 0.31 kcal/day, P = 0.005). Since food intake was not different between groups, increased EE likely accounts for the reduced body fat mass (KO: 8.8 ± 1.1% vs. WT: 14.5 ± 1.3%, P = 0.003) and circulating leptin levels (KO: 0.7 ± 0.2 ng/ml vs. WT: 1.9 ± 0.3 ng/ml, P = 0.008). Interestingly, the observed increase in adjusted EE in myostatin-deficient mice occurred despite dramatically reduced ambulatory activity levels (−50% vs. WT, P < 0.05). The absence of hyperphagia together with increased EE in myostatin-deficient mice suggests that increased leptin sensitivity may contribute to their lean phenotype. Indeed, leptin-induced anorexia (KO: −17 ± 1.2% vs. WT: −5 ± 0.3%) and weight loss (KO: −2.2 ± 0.2 g vs. WT: −1.6 ± 0.1, P < 0.05) were increased in myostatin-deficient mice compared with WT controls. We conclude that increased EE, together with increased leptin sensitivity, contributes to low fat mass in mice lacking myostatin.
Tubular proteinuria in mice and humans lacking the intrinsic lysosomal protein SCARB2/Limp-2
Authors: Desmond M. J. , Lee D. , Fraser S. A. , Katerelos M. , Gleich K. , Martinello P. , Li Y. Q. , Thomas M. C. , Michelucci R. , Cole A. J. , Saftig P. , Schwake M. , Stapleton D. , Berkovic S. F. , Power D. A.
Published: March 2011

Deficiency of the intrinsic lysosomal protein human scavenger receptor class B, member 2 (SCARB2; Limp-2 in mice) causes collapsing focal and segmental glomerular sclerosis (FSGS) and myoclonic epilepsy in humans, but patients with no apparent kidney damage have recently been described. We now demonstrate that these patients can develop tubular proteinuria. To determine the mechanism, mice deficient in Limp-2, the murine homolog of SCARB2, were studied. Most low-molecular-weight proteins filtered by the glomerulus are removed in the proximal convoluted tubule (PCT) by megalin/cubilin-dependent receptor-mediated endocytosis. Expression of megalin and cubilin was unchanged in Limp-2−/− mice, however, and the initial uptake of injected Alexa Fluor 555-conjugated bovine serum albumin (Alexa-BSA) was similar to wild-type mice, indicating that megalin/cubilin-dependent, receptor-mediated endocytosis was unaffected. There was a defect in proteolysis of reabsorbed proteins in the Limp-2−/− mice, demonstrated by the persistence of Alexa-BSA in the PCT compared with controls. This was associated with the failure of the lysosomal protease cathepsin B to colocalize with Alexa-BSA and endogenous retinol-binding protein in kidneys from Limp-2−/− mice. The data suggest that tubular proteinuria in Limp-2−/− mice is due to failure of endosomes containing reabsorbed proteins to fuse with lysosomes in the proximal tubule of the kidney. Failure of proteolysis is a novel mechanism for tubular proteinuria.
In vivo activity of epoxide hydrolase according to sequence variation affects the progression of human IgA nephropathy
Authors: Lee Jung Pyo , Yang Seung Hee , Kim Dong Ki , Lee Hajeong , Kim Bora , Cho Joo-Youn , Yu Kyung-Sang , Paik Jin Ho , Kim Myounghee , Lim Chun Soo , Kim Yon Su
Published: March 2011

Epoxyeicosatrienoic acid (EET) regulates the functional integrity of the endothelium. It is hypothesized that the activity of epoxide hydrolase ( EPHX2), which determines EET concentration through hydrolysis, may affect the progression of glomerulonephritis. Here, we evaluated the relationship between genetic variations, the in vivo activity of EPHX2, and progression of IgA nephropathy (IgAN). Three single-nucleotide polymorphisms (SNPs) [rs41507953 (K55R), rs751141 (R287Q), and rs1042032] were traced in 401 IgAN patients and 402 normal healthy controls. The in vivo activity of EPHX2 was assessed by measuring substrates/metabolites of the enzyme. None of the polymorphism frequencies differed significantly between patients and controls. However, patients carrying the variant allele (A) of rs751141 possessed better kidney survival than those with the wild-type allele (G; P < 0.001). This association remained significant after adjustment for several risk factors (hazard ratio 1.83, 95% confidence interval 1.13–2.96, P = 0.014). Vascular damage was more prominent in kidney biopsies from patients carrying the G allele of rs751141. The in vivo activity of EPHX2, assessed by the epoxyoctadecenoic acid/dihydroxyoctadecenoic acid ratio using liquid chromatography/mass spectrometry analysis, was elevated in patients with the G allele. The expression of EPHX2 in the human kidney was independent of the sequence variation of the rs751141 allele. Variant rs41507953 was not present in this cohort, and rs1042032 was not associated with progression. Thus the specific measures which regulate EPHX2 activity should be designed for potential therapeutics.
Grey-Blue Regression in Melanoma In Situ—Evaluation on 111 Cases
Authors: Bassoli S. , Borsari S. , Ferrari C. , Giusti F. , Pellacani G. , Ponti G. , Seidenari S.
Published: March 2011

As fibrosis and melanosis are often seen in malignant melanoma, the presence of dermoscopic signs of regression may represent a clue for the diagnosis of malignancy. Our aim was to assess the frequency and extent of 11 dermoscopic features of regression evaluating dermoscopic images of 111 melanomas in situ (MIS). Regression structures (grey-blue areas, white areas, peppering, and/or blue-whitish veil) were present in 80.1% of the lesions. Approximately 80% of the lesions showed regression of dermoscopic structures and light brown areas. Most lesions showed the presence of grey-blue areas (74.7%), whereas peppering was observable in 30.6% of MIS. Areas of fibrosis were mainly observable as structureless areas with a pinkish hue (50.4%). Based on our data, the reticular pattern of blue regression and light brown areas can be considered a significant discriminator and a reliable predictor of MIS.