bluuebunny/crossref_metadata_2025 huggingface dataset:
The Sterilization of Suspensions Contaminated with Microorganisms Using Ultrasound Irradiation
Authors: Nakamura Takashi , Okawa Hirokazu , Hosokawa Ryouta , Saito Tomonao , Kawamura Youhei , Sugawara Katsuyasu
Published: July 2010

We investigated the influence of suspended particles on the sterilization efficiency of ultrasound wave applied to microbial suspensions. A microbial solution containing 2.0×102 cfu/ml of Bacillus bacteria but no suspended particles was sterilized more efficiently by 28 kHz irradiation inducing a strong impact-like physical action compared to 200 kHz irradiation inducing a strong chemical reaction through the generation of radicals and heat. This sterilization effect was enhanced by the suspension of silicon dioxide or green tuff when irradiated at 28 kHz. However, the irradiation of green tuff microbial suspension at 200 kHz resulted in a remarkable decrease in the sterilization efficiency. This reduction was caused by divalent iron in green tuff reacting with radicals generated by 200 kHz irradiation, thus reducing the amount of radicals used for sterilization. Our results suggest that 28 kHz ultrasound irradiation is optimal for the sterilization of microbial suspensions.
A Study on Cleaning Ability of Oscillating Bubbles Driven by Low-Frequency Ultrasound
Authors: Tanimura Yukio , Yoshida Kenji , Watanabe Yoshiaki
Published: July 2010

In this paper, we demonstrate the cleaning ability of oscillating bubbles, on the basis of optical observations of bubble behaviors and cleaning process using a high-speed video camera. It was shown that a bubble cluster was formed after the collapse of the initial bubble. The bubble cluster consisted of a main bubble and many small bubbles. In addition, optical observations clearly revealed that the oscillations of these microbubbles removed a thin ink film bonded to the surface of a slide glass. From the analysis of the relationship between bubble oscillation and cleaning effect, it was confirmed that the cleaned area increased with an increasing amplitude of bubble oscillation, although there was a poor correlation between cleaned area and bubble oscillation. Moreover, the observed results suggested that a pressure ranging from several tens kPa to MPa was generated on the slide glass by hydrodynamic phenomena; micro jet and secondary wave were emitted by the oscillating bubble. Our experimental results lead to the understanding of the cleaning mechanism in ultrasonic cleaning techniques.
Dispersion Method Using Focused Ultrasonic Field
Authors: Kim Jungsoon , Kim Moojoon , Ha Kanglyel , Chu Minchul
Published: July 2010

The dispersion of powders into liquids has become one of the most important techniques in high-tech industries and it is a common process in the formulation of various products, such as paint, ink, shampoo, beverages, and polishing media. In this study, an ultrasonic system with a cylindrical transducer is newly introduced for pure nanoparticle dispersion. The acoustics pressure field and the characteristics of the shock pulse caused by cavitation are investigated. The frequency spectrum of the pulse from the collapse of air bubbles in the cavitation is analyzed theoretically. It was confirmed that a TiO2 water suspension can be dispersed effectively using the suggested system.
Longitudinal Vibration Characteristics Required to Cut a Circle by Ultrasonic Vibration
Authors: Asami Takuya , Miura Hikaru
Published: July 2010

Currently, lasers and water jets are used to cut circles in brittle materials such as ceramics. However, a disadvantage of these methods is that the conventional equipment is large and complex. To resolve this issue, a method using the ultrasonic vibration of a hollow-type stepped horn for cutting is developed. We consider that this equipment can be simplified and miniaturized. The shape of the hollow-type stepped horn and the characteristics of the longitudinal vibration required to obtain excellent cutting properties were examined. As a result, the most appropriate depth of the hollow part is one-quarter of the wavelength for a hollow-type stepped horn that vibrates longitudinally. The amplification factor is proportional to the cross-sectional ratio providing the cross-sectional ratio does not exceed 4.6. The characteristics of the longitudinal vibration of the hollow-type stepped horn when the static pressing force at the tip of the horn is varied were also examined. It was clarified that the ultrasonic vibration of a hollow-type stepped horn can be used to cut brittle materials.
Examination of Sandwich-Type Multidegree-of-Freedom Spherical Ultrasonic Motor
Authors: Lu Bo , Aoyagi Manabu , Takano Takehiro , Tamura Hideki
Published: July 2010

A sandwich-type multidegree-of-freedom (MDOF) spherical ultrasonic motor (SUSM) is newly proposed. The motor consists of a spherical rotor and two stator vibrators holding the rotor. This structure has both a rotor support and a preload mechanism. The stator excites five vibration modes, and the rotor can rotate on three axes. An experiment of a torque composition of two stators was carried out. The contact surface between the rotor and the stators forms a spherical surface. Moreover, a displacement magnification mechanism, which was used in the former model to rotate on theZ-axis, is no longer necessary. Hence the stator is simpler in construction than the former model. In this paper, we describe the construction and the operating principle of the MDOF ultrasonic motor, modal analysis results for the stator, and some measurement results from trial manufacturing. The miniaturization of the motor and increase in torque were successfully realized.
Design and Characteristics of Mode-Coupling LiNbO3 Ultrasonic Motor Depended on Width-to-Length Ratio of the Stator Vibrator
Authors: Tamura Hideki , Morooka Takanori , Yamayoshi Yasuhiro , Aoyagi Manabu , Takano Takehiro , Hirose Seiji
Published: July 2010

A miniature ultrasonic motor fabricated from a LiNbO3 rectangular plate was studied to improve its rotation characteristics. In this motor, the coupling modes of in-plane longitudinal and flexural modes caused by crystal anisotropy are used to realize a single-phase drive motor. The mode coupling vibrator is designed to have crystal cut angles and the width-to-length ratio W/L of the vibrator shape. In this study, we noted the new coupling condition of W/L≈0.84 compared with the conventional ratio of W/L=0.255. We considered the mechanism of the mode coupling and the design of the stator vibrator by finite element method analysis and experiments. From the results, we fabricated and investigated prototype motors of the vibrator with dimensions of 10×2.55×0.5 and 4.10×3.48×0.5 mm3. The newly designed motor with the vibrator of W/L=0.849 improved the motor characteristics for the equalization of rotation in both directions.
Development of Robust Sensing System for Puncture Needle-Type Ultrasonography
Authors: Yoshizawa Masasumi , Irie Takasuke , Itoh Kouichi , Moriya Tadashi
Published: July 2010

In this paper, we propose a robust sensing system that protects a thin rod sensor used in the measurements of acoustic impedance in puncture needle-type ultrasonography. In this ultrasonograpy, an ultrasonic interference method using the thin rod sensor is applied. Since the thin rod made of fused quartz is not robust, a protector is required for the thin rod sensor in in vivo measurement. Therefore, the sensing system has consisted of a thin rod sensor and a hollow pipe with a top cover to protect the sensor. For the observation of a low-impedance material such as biological tissue, the measurement method requires an impedance-transforming layer as the top cover. However, since the optimum thickness of the layer decreases as the measurement frequency increases, the decrease in the thickness causes deformation of the layer. The deformation introduces an error in the measurement. To avoid such a problem, we developed a robust sensing system. The system consists of a quarter-wavelength layer that functions as an impedance transformer and a half-wavelength (or multiple times of a half-wavelength) layer that provides the robustness of the system. We confirmed experimentally the effectiveness of the robust sensing system for acoustic impedance measurement of a tissue sample by the acoustic impedance difference method. The experimental results show that the robust sensing system is useful for puncture needle-type ultrasonography.
Proper Analytic Point Spread Function for Lateral Modulation
Authors: Sumi Chikayoshi , Shimizu Kunio , Matsui Norihiko
Published: July 2010

For ultrasonic lateral modulation for the imaging and measurement of tissue motion, better envelope shapes of the point spread function (PSF) than of a parabolic function are searched for within analytic functions or windows on the basis of the knowledge of the ideal shape of PSF previously obtained, i.e., having a large full width at half maximum and short feet. Through simulation of displacement vector measurement, better shapes are determined. As a better shape, a new window is obtained from a Turkey window by changing Hanning windows by power functions with an order larger than the second order. The order of measurement accuracies obtained is as follows, the new window > rectangular window > power function with a higher order > parabolic function > Akaike window.
Measurement of Elastic Properties of Tissue by Shear Wave Propagation Generated by Acoustic Radiation Force
Authors: Tabaru Marie , Azuma Takashi , Hashiba Kunio
Published: July 2010

Acoustic radiation force (ARF) imaging has been developed as a novel elastography technology to diagnose hepatic disease and breast cancer. The accuracy of shear wave speed estimation, which is one of the applications of ARF elastography, is studied. The Young's moduli of pig liver and foie gras samples estimated from the shear wave speed were compared with those measured the static Young's modulus measurement. The difference in the two methods was 8%. Distance attenuation characteristics of the shear wave were also studied using finite element method (FEM) analysis. We found that the differences in the axial and lateral beam widths in pressure and ARF are 16 and 9% at F-number=0.9. We studied the relationship between two branch points in distance attenuation characteristics and the shape of ARF. We found that the maximum measurable length to estimate shear wave speed for one ARF excitation was 8 mm.
Effect of Viscoelasticity of Vessel Walls on Pulse Wave
Authors: Saito Masashi , Yamamoto Yuya , Matsukawa Mami , Watanabe Yoshiaki , Furuya Mio , Asada Takaaki
Published: July 2010

The pulse wave comes from the displacement of surface skin and is composed of incident and reflected waves. Since the properties of the reflected wave change considerably owing to the viscoelasticity of the vessel walls, the analysis of the reflected wave is considered to be useful for evaluating arterial stiffness; thereby, appropriate estimation of the incident wave is important for separating the pulse wave. Here, the incident wave is generated by a forward wave, which is the intravascular pressure caused by blood flow. In the former analysis, we assumed the blood vessel as an elastic tube and estimated the forward wave from the blood flow velocity waveform. In this study, we used a viscoelastic model to estimate a more appropriate forward wave. In this estimation, we used viscoelastic properties similar to those of bovine aorta, human aorta, or human artery. The estimated forward waves showed that the difference in the viscous properties of vessel walls causes minimal changes in the forward waves, which were also similar to that estimated using the elastic model. The result tells us that the elastic model is acceptable and useful for the estimation of forward wave, incident wave, and reflected wave, which enables the simple evaluation of the viscoelastic properties of vessel walls.
Acoustic Signal Characterization of Phase Change Nanodroplets in Tissue-Mimicking Phantom Gels
Authors: Asami Rei , Ikeda Teiichiro , Azuma Takashi , Umemura Shinichiro , Kawabata Ken-ichi
Published: July 2010

To apply superheated perfluorocarbon nanodroplets to tumor diagnosis and treatment, acoustic signals formed upon the vaporization of droplets in tissue-mimicking phantoms were measured with 3 MHz ultrasound. A characteristic impulse wave was associated with phase change induction with 100 cycles of ultrasound at a 9 MPa peak negative pressure, observed as an intensity change in B-mode imaging. In addition, the subsequent impulse waves were observed only from the phase change induction in gels. Therefore, these subsequent impulse waves were suggested to be characteristic features of the vaporization of superheated nanodroplets at rigid boundaries. Furthermore, such impulse waves reflect the properties of surrounding environments such as elasticity and viscosity in the gel. The findings of this study would lead to a novel microscale tissue characterization method applicable to local sites.
Coagulation of Large Regions by Creating Multiple Cavitation Clouds for High Intensity Focused Ultrasound Treatment
Authors: Inaba Yuta , Yoshizawa Shin , Umemura Shin-ichiro
Published: July 2010

High-Intensity focused ultrasound (HIFU) is attracting attention as a minimally invasive therapeutic modality. However, it has a problem of a long treatment time. To improve its treatment throughput, we developed a method of coagulating a large region at one time utilizing multiple clouds of cavitation. It is known that acoustic cavitation generated in the focal region of HIFU enhances tissue heating. In the experiment in this study, the focal distance was changed using an annular array transducer. Cavitation clouds were generated at three positions within a fraction of a second by high-intensity ultrasound pulses. The tissues in the vicinity of the cavitation clouds were coagulated simultaneously with non-spherically focused ultrasound waves at a relatively low intensity. The result suggests that the HIFU treatment time is significantly shortened by employing the proposed method.
Myocardial Strain Imaging with High-Performance Adaptive Dynamic Grid Interpolation Method
Authors: Bu Shuhui , Yamakawa Makoto , Shiina Tsuyoshi
Published: July 2010

The accurate assessment of local myocardial strain is important for diagnosing ischemic heart diseases because decreased myocardial motion often appears in the early stage. Calculating the spatial derivation of displacement is a necessary step in the strain calculation, but the numerical calculation is extremely sensitive to noise. Commonly used smoothing methods are the moving-average and median filters; however, these methods have a trade-off between spatial resolution and accuracy. A novel smoothing/fitting method is proposed for overcoming this problem. In this method, the detected displacement vectors are discretized at mesh nodes, and virtual springs are connected between adjacent nodes. By controlling the elasticity of the virtual springs, misdetected displacements are fitted without the above problem. Further improvements can be achieved by applying a Kalman filter for position tracking, and then calculating the strain from the accumulated displacement vectors. From the simulation results, we conclude that the proposed method improves the accuracy and spatial resolution of the strain images.
Physical Considerations on Bernoulli's Law for Mitral Valve Regurgitation
Authors: Tanaka Tomohiko , Hashiba Kunio
Published: July 2010

The simplified Bernoulli's equation is widely used in cardiology to measure the pressure difference between the left ventricle (LV) and the left atrium (LA). Even though this is a standard method, its derivation has not been well-clarified physically, which may lead to inappropriate usage of the method. In this study, derivation of the simplified Bernoulli's equation is presented with five assumptions: incompressible, irrotational, steady-state, negligible LV–LA height difference, and LA open space. Each assumption is analytically and numerically discussed as quantitatively as possible. We found that three factors, the LA size, the measurement location of regurgitation velocity, and the patient position in measuring regurgitation, need to be considered for appropriate usage of the simplified Bernoulli's equation.
Visualization of Ultrasonic Fields Transmitted from Bovine Bones by Hydrophone Scanning
Authors: Ohno Masahiro , Ikeda Nami , Ohira Kaori , Ogawa Yukari
Published: July 2010

An experimental study on the field disturbance of ultrasound transmitted through bones has been performed. Ultrasonic waves at 1.1 and 3.5 MHz were radiated towards bovine bone samples and the transmitted waves from the bones were detected by a small hydrophone. Two-dimensional images showing ultrasonic field distributions were constructed by scanning the hydrophone in a transverse plane of the ultrasonic beam. The ultrasonic fields were disturbed by a cortical bone both at 1.1 and 3.5 MHz. Disturbance by a cancellous bone was small at 1.1 MHz but large at 3.5 MHz. Large amounts of scattered waves were generated from a cancellous bone at 3.5 MHz. These results can be used for the determination of the dimensions of setups for in vivo and in vitro measurement of bone-transmitted ultrasound.
Preliminary Study of Broadband Transducer for Measurement of Bone Characteristics
Authors: Irie Takasuke , Koumoto Kouhei , Tanabe Masayuki , Tagawa Norio , Okubo Kan , Akiyama Iwaki , Itoh Kouichi
Published: July 2010

The purpose of the study is to diagnose bone diseases using the ultrasonic image. We investigate the broadband transducer with a 0.5–5 MHz frequency range. We fabricated two types of transducers with a thin piezoelectric plate bonded with a thick plate resonator. One is an acoustic lens transducer made of flat lead zirconate titanate (PZT) material, and another is a concave transducer made of PZT rod-polymer 1–3 composite material. The application of the transducers to clinical diagnosis involves the measurement of frequency-dependent characteristics of bone by the penetration method. We measured ultrasonic waves radiated from the transducer at the focal point, and performed frequency analysis. As a result, a flat frequency characteristic of the concave transducer was obtained.
Development of an Estimation Method for Damper Design in Static Elastography
Authors: Sato Takayuki , Sato Shizuka , Watanabe Yasuaki , Goka Shigeyoshi , Sekimoto Hitoshi
Published: July 2010

The estimation of elasticity distribution in static elastography methods strongly depends on the shape of the transducer head. It is known that the insertion of a damper layer is effective in improving the spatial nonuniformity of an applied strain distribution. We have developed a new estimation method for assessing the effectiveness of this technique through structural analysis using the finite element method and acoustic analysis using the finite-difference time-domain method with multilayered tissues. From the results, the strain flatness inside the compressed tissue is markedly improved, especially near the tissue surface, by inserting a damper layer between the transducer and the tissue surface. The elasticity of an inclusion and the deeper region of a three-layer tissue are also adequately imaged.
Numerical Simulation of Target Range Estimation Using Ambient Noise Imaging with Acoustic Lens
Authors: Mori Kazuyoshi , Ogasawara Hanako , Nakamura Toshiaki , Tsuchiya Takenobu , Endoh Nobuyuki
Published: July 2010

In ambient noise imaging (ANI), each pixel of a target image is mapped by either monochrome or pseudo color to represent its acoustic intensity in each direction. This intensity is obtained by measuring the target object's reflecting or scattering wave, with ocean background noise serving as the sound source. In the case of using an acoustic lens, the ANI system creates a C-mode-like image, where receivers are arranged on a focal plane and each pixel's color corresponds to the intensity of each receiver output. There is no consideration for estimating a target range by this method, because it is impossible to measure the traveling time between a transducer and a target by a method like an active imaging sonar. In this study, we tried to estimate a target range using the ANI system with an acoustic lens. Here, we conducted a numerical simulation of sound propagation based on the principle of the time reversal mirror. First, instead of actual ocean measurements in the forward propagation, we calculated the scattering wave from a rigid target object in an acoustic noise field generated by a large number of point sources using the two-dimensional (2D) finite difference time domain (FDTD) method. The time series of the scattering wave converged by the lens was then recorded on each receiver. The sound pressure distribution assuming that the time-reversed wave of the scattering wave was reradiated from each receiver position was also calculated using the 2D FDTD method in the backward propagation. It was possible to estimate a target range using the ANI system with an acoustic lens, because the maximum position of the reradiated sound pressure field was close to the target position.
Design for Underwater Aplanatic Acoustic Mirror
Authors: Sato Yuji , Mizutani Koichi , Wakatsuki Naoto , Nakamura Toshiaki
Published: July 2010

Underwater acoustic lenses are useful devices for underwater imaging because of their small dimension and low power consumption but have a problem under the condition of changing water temperature because the refractive index depends on the water temperature. To solve this problem, we propose aplanatic acoustic mirrors, which consist of two aspherical mirrors and can remove spherical and coma aberrations. These mirrors are designed by a method used in the Ritchey Chrétien astronomical telescopes. The aplanatic mirror shows a larger focal sound pressure and better temperature characteristic than an aplanatic acoustic lens but has a narrow field of angle. Then, an off-axis aplanatic mirror, which consists of two aspherical off-axis mirrors, is designed by extraction of parts from a normal aplanatic mirror to obtain a wider field of angle.
Measurements of Breaking Wave Noise in the Sea-Cliff Zone
Authors: Cho Sungho , Choi Jee Woong
Published: July 2010

This paper presents measurements of the breaking wave noise originated at a sea-cliff zone along the coast of Ando in southern Korea. The breaking noise was recorded using an omni-directional hydrophone deployed at a depth of 3 m at a location approximately 80 m from the sea-cliff. A spectrogram indicates that the breaking noise persists for a few seconds after a sudden onset with broad-band acoustic energy. The source level per unit area is estimated from the received power-averaged spectral density which was compensated for the acoustic propagation effect from the effective source region to the receiver, predicted using the parabolic equation method. The form of the source level spectrum of the waves breaking against the sea-cliff is similar to that reported in the literature for the plunging breakers in the surf zone. However, the overall source level of the waves breaking against the sea-cliff is 5 to 15 dB higher than that of the plunging breakers.
Experimental Study of Radiation Impedance with Effect of Reflected Wave from Sonar Dome
Authors: Kim Jungsoon , Kim Moojoon , Ha Kanglyeol , Seo Heeseon , Joh Cheeyong
Published: July 2010

The radiation impedance of arrayed vibrators is analyzed experimentally when the array has a reflector. To verify the effect of the reflector, the radiation impedance with the reflector was calculated. To estimate the radiation impedance change, the input impedance of the vibrator was calculated using an equivalent circuit model. The input impedance was dependant on the location of the vibrators. The experimental results show a similar tendency to the theoretical results. It is noted that the equivalent circuit model for theoretical analysis is useful for estimating the radiation impedance change caused by the reflected wave.
Underwater Acoustic Communication Channel Simulator for Flat Fading
Authors: Park Jihyun , Park Kyu-Chil , Yoon Jong Rak
Published: July 2010

Time-variant sea surface scattering and Doppler spreading due to source/receiver motion cause the signal fading stochastically in amplitude and phase fluctuation. Consequently, the performance of underwater acoustic communication systems are degraded, and high-speed digital communication is disrupted. In this study, a channel simulator for flat fading over time-variant sea surface scattering and Doppler spread in source/receiver motion is presented. Rayleigh and Rice fading models are adopted and their distributions are compared with the distribution measured in a water tank. The bit error rate of binary phase shift keying (BPSK) and binary frequency shift keying (BFSK) for flat fading is examined to evaluate the simulator performance.
Experiment Results of Time-Reversal Communication at the Range of 300 km
Authors: Shimura Takuya , Ochi Hiroshi , Watanabe Yoshitaka , Hattori Takehito
Published: July 2010

We have researched on long horizontal time-reversal communication in the deep ocean, to be used for communication with autonomous underwater vehicle (AUV) in future, and proposed the method of combining time reversal with adaptive equalization. The pervious at-experiments were carried out at the ranges from 10 to 100 km with a virtual time-reversal array. In our latest sea trial, the experiment for passive time-reversal communication was executed with a real receiver array at the range of 300 km. This was the first implementation of time-reversal communication at such a range as an experiment intended for communication including the source movement. In this experiment, the source was suspended from the research vessel, thus drifted due to the ship motion. The proposed method could achieve error-free demodulation in spite of such drifting motion. The M-sequence signal and chirp pulse were used as the probe signal for passive time reversal. The results in case of M-sequence were better than those in case of chirp pulse.
Beam Forming Property of Coded Acoustic Signal for Long-Range Acoustic Navigation of a Cruising Autonomous Underwater Vehicle
Authors: Watanabe Yoshitaka , Ochi Hiroshi , Shimura Takuya , Hattori Takehito
Published: July 2010

The property of beam forming by a receiver array placed on the side surface of an autonomous underwater vehicle (AUV) is considered in this paper. The aim of this study is to develop a long-range acoustic navigation system for a cruising AUV on the basis of the estimation of the horizontal direction of arrival (DOA) of an acoustic signal from reference source. The acoustic signal is coded using a maximum length sequence code. The influence of multipath waves to the estimation of horizontal DOA was particularly studied. When there are several multipath waves from various vertical DOAs, even if the horizontal DOAs of all the waves are the same, the multipath waves are influential to the estimation of the horizontal DOA. Then, the coded signal is useful to avoid the influence of the multipath waves. An exploratory experiment on the propagation of the acoustic signal for distance of about 16.6 km was performed in Suruga Bay. By simulating the condition similar to the experiment, it was indicated that the accuracy of the estimation of the horizontal DOA is within zero point several degrees in the experiment.
Numerical Analysis of Pulse Wave Propagation in Lützow-Holm Bay of the Antarctic Ocean Calculated by the Parabolic Equation Method
Authors: Tsuchiya Takenobu , Matsumoto Sayuri , Anada Tetsuo , Endoh Nobuyuki
Published: July 2010

Ocean climate research is being carried out considering the use of an autonomous underwater vehicle (AUV) in the Antarctic Ocean. In this study, to understand the characteristics of sound propagation in Lützow-Holm bay of the Antarctic Ocean for acoustical communication with an AUV, we estimate pulse waveforms using a two-dimensional (2D) parabolic equation method. We assumed that one transmitter each is placed at three different depths (50, 100, and 150 m) and the propagation range is up to 39 km in a traverse line OW. We calculate the pulse propagation in the Antarctic Ocean using three bottom models to determine its influences on pulse wave amplitude by bathymetry. The results show a variation in pulse wave amplitude of about 3 dB when the source depth is 100 m. The pulse amplitude varies from 5 to -10 dB when the source depth changes from 50 to 150 m.
Modeling web quality using a probabilistic approach
Authors: Malak Ghazwa , Sahraoui Houari , Badri Linda , Badri Mourad
Published: July 2010

Web-based applications are software systems that continuously evolve to meet users' needs and to adapt to new technologies. Assuring their quality is then a difficult, but essential task. In fact, a large number of factors can affect their quality. Considering these factors and their interaction involves managing uncertainty and subjectivity inherent to this kind of applications. In this article, we present a probabilistic approach for building Web quality models and the associated assessment method. The proposed approach is based on Bayesian Networks. A model is built following a four-step process consisting in collecting quality characteristics, refining them, building a model structure, and deriving the model parameters.

The feasibility of the approach is illustrated on the important quality characteristic of
Navigability design
. To validate the produced model, we conducted an experimental study with 20 subjects and 40 web pages. The results obtained show that the scores given by the used model are strongly correlated with navigability as perceived and experienced by the users.
Discovery of latent subcommunities in a blog's readership
Authors: Adams Brett , Phung Dinh , Venkatesh Svetha
Published: July 2010

The blogosphere has grown to be a mainstream forum of social interaction as well as a commercially attractive source of information and influence. Tools are needed to better understand how communities that adhere to individual blogs are constituted in order to facilitate new personal, socially-focused browsing paradigms, and understand how blog content is consumed, which is of interest to blog authors, big media, and search. We present a novel approach to blog subcommunity characterization by modeling individual blog readers using mixtures of an extension to the LDA family that jointly models phrases and time, Ngram Topic over Time (NTOT), and cluster with a number of similarity measures using Affinity Propagation. We experiment with two datasets: a small set of blogs whose authors provide feedback, and a set of popular, highly commented blogs, which provide indicators of algorithm scalability and interpretability without prior knowledge of a given blog. The results offer useful insight to the blog authors about their commenting community, and are observed to offer an integrated perspective on the topics of discussion and members engaged in those discussions for unfamiliar blogs. Our approach also holds promise as a component of solutions to related problems, such as online entity resolution and role discovery.
Proline Metabolism and Microenvironmental Stress
Authors: Phang James M. , Liu Wei , Zabirnyk Olga
Published: July 2010

Proline, the only proteinogenic secondary amino acid, is metabolized by its own family of enzymes responding to metabolic stress and participating in metabolic signaling. Collagen in extracellular matrix, connective tissue, and bone is an abundant reservoir for proline. Matrix metalloproteinases degrading collagen are activated during stress to make proline available, and proline oxidase, the first enzyme in proline degradation, is induced by p53, peroxisome proliferator-activated receptor γ (PPARγ) and its ligands, and by AMP-activated protein kinase downregulating mTOR. Metabolism of proline generates electrons to produce ROS and initiates a variety of downstream effects, including blockade of the cell cycle, autophagy, and apoptosis. The electrons can also enter the electron transport chain to produce adenosine triphosphate for survival under nutrient stress. Pyrroline-5-carboxylate, the product of proline oxidation, is recycled back to proline with redox transfers or is sequentially converted to glutamate and alpha-ketoglutarate. The latter augments the prolyl hydroxylation of hypoxia-inducible factor-1α and its proteasomal degradation. These effects of proline oxidase, as well as its decreased levels in tumors, support its role as a tumor suppressor. The mechanism for its decrease is mediated by a specific microRNA. The metabolic signaling by proline oxidase between oxidized low-density lipoproteins and autophagy provides a functional link between obesity and increased cancer risk.
The Endocannabinoid System and Its Relevance for Nutrition
Authors: Maccarrone Mauro , Gasperi Valeria , Catani Maria Valeria , Diep Thi Ai , Dainese Enrico , Hansen Harald S. , Avigliano Luciana
Published: July 2010

Endocannabinoids bind to cannabinoid, vanilloid, and peroxisome proliferator-activated receptors. The biological actions of these polyunsaturated lipids are controlled by key agents responsible for their synthesis, transport and degradation, which together form an endocannabinoid system (ECS). In the past few years, evidence has been accumulated for a role of the ECS in regulating food intake and energy balance, both centrally and peripherally. In addition, up-regulation of the ECS in the gastrointestinal tract has a potential impact on inflammatory bowel diseases. In this review, the main features of the ECS are summarized in order to put in better focus our current knowledge of the nutritional relevance of endocannabinoid signaling and of its role in obesity, cardiovascular pathologies, and gastrointestinal diseases. The central and peripheral pathways that underlie these effects are discussed, as well as the possible exploitation of ECS components as novel drug targets for therapeutic intervention in eating disorders.
Physiological Insights Gained from Gene Expression Analysis in Obesity and Diabetes
Authors: Keller Mark P. , Attie Alan D.
Published: July 2010

Microarray technology permits the interrogation of nearly all expressed genes under a wide range of conditions. Patterns of gene expression in response to obesity and diabetes have yielded important insights into the pathogenesis of diabetes and its relationship to obesity. In muscle, microarray studies have motivated research into mitochondrial function. In adipose tissue, clues have pointed to the importance of inflammation in obesity. New adipocyte-derived hormones involved in insulin resistance have been found; a notable example is retinol binding protein 4. In liver, genes responsive to master regulators of lipid metabolism have been identified. In β-cells, genes involved in cell survival, cell proliferation, and insulin secretion have been identified. These studies have greatly expanded our understanding of mechanisms underlying the pathogenesis of obesity-induced diabetes. When combined with genetic information, microarray data can be used to construct causal network models linking gene expression with disease.
Targeting Inflammation-Induced Obesity and Metabolic Diseases by Curcumin and Other Nutraceuticals
Authors: Aggarwal Bharat B.
Published: July 2010

Extensive research within the past two decades has revealed that obesity, a major risk factor for type 2 diabetes, atherosclerosis, cancer, and other chronic diseases, is a proinflammatory disease. Several spices have been shown to exhibit activity against obesity through antioxidant and anti-inflammatory mechanisms. Among them, curcumin, a yellow pigment derived from the spice turmeric (an essential component of curry powder), has been investigated most extensively as a treatment for obesity and obesity-related metabolic diseases. Curcumin directly interacts with adipocytes, pancreatic cells, hepatic stellate cells, macrophages, and muscle cells. There, it suppresses the proinflammatory transcription factors nuclear factor-kappa B, signal transducer and activators of transcription-3, and Wnt/β-catenin, and it activates peroxisome proliferator-activated receptor-γ and Nrf2 cell-signaling pathways, thus leading to the downregulation of adipokines, including tumor necrosis factor, interleukin-6, resistin, leptin, and monocyte chemotactic protein-1, and the upregulation of adiponectin and other gene products. These curcumin-induced alterations reverse insulin resistance, hyperglycemia, hyperlipidemia, and other symptoms linked to obesity. Other structurally homologous nutraceuticals, derived from red chili, cinnamon, cloves, black pepper, and ginger, also exhibit effects against obesity and insulin resistance.
Iron, Lead, and Children's Behavior and Cognition
Authors: Kordas Katarzyna
Published: July 2010

Iron deficiency (ID) is the most common micronutrient deficiency in the world, with consequences of ID and ID anemia (IDA) in young children including behavioral and cognitive deficits. In turn, lead exposure is one of the most common environmental toxicants affecting children. Elevated blood lead levels (BLLs) in young children are also associated with behavioral and cognitive deficits. The metabolic and physiological connections between iron and lead, including a common route of entry into the body and similar neural targets, suggest a considerable overlap in their effects on functional outcomes. Very few studies have examined the existence of increased susceptibility to lead neurotoxicity in children with ID, but there is evidence that ID and BLL are independently associated with cognition and behavior. Children's susceptibility to both ID and elevated BLLs will likely depend on the timing and severity of both exposures, something that should be investigated systematically.
Sepsis and glucocorticoids downregulate the expression of the nuclear cofactor PGC-1β in skeletal muscle
Authors: Menconi Michael J. , Arany Zoltan P. , Alamdari Nima , Aversa Zaira , Gonnella Patricia , O'Neal Patrick , Smith Ira J. , Tizio Steven , Hasselgren Per-Olof
Published: July 2010

Muscle wasting during sepsis is at least in part regulated by glucocorticoids and is associated with increased transcription of genes encoding the ubiquitin ligases atrogin-1 and muscle-specific RING-finger protein-1 (MuRF1). Recent studies suggest that muscle atrophy caused by denervation is associated with reduced expression of the nuclear cofactor peroxisome proliferator-activated receptor-γ coactivator (PGC)-1β and that PGC-1β may be a repressor of the atrogin-1 and MuRF1 genes. The influence of other muscle-wasting conditions on the expression of PGC-1β is not known. We tested the influence of sepsis and glucocorticoids on PGC-1β and examined the potential link between downregulated PGC-1β expression and upregulated atrogin-1 and MuRF1 expression in skeletal muscle. Sepsis in rats and mice and treatment with dexamethasone resulted in downregulated expression of PGC-1β and increased expression of atrogin-1 and MuRF1 in the fast-twitch extensor digitorum longus muscle, with less pronounced changes in the slow-twitch soleus muscle. In additional experiments, adenoviral gene transfer of PGC-1β into cultured C2C12 myotubes resulted in a dose-dependent decrease in atrogin-1 and MuRF1 mRNA levels. Treatment of cultured C2C12 myotubes with dexamethasone or PGC-1β small interfering RNA (siRNA) resulted in downregulated PGC-1β expression and increased protein degradation. Taken together, our results suggest that sepsis- and glucocorticoid-induced muscle wasting may, at least in part, be regulated by decreased expression of the nuclear cofactor PGC-1β.
S-Layer Glycoproteins and Flagellins: Reporters of Archaeal Posttranslational Modifications
Authors: Jarrell Ken F. , Jones Gareth M. , Kandiba Lina , Nair Divya B. , Eichler Jerry
Published: July 2010

Many archaeal proteins undergo posttranslational modifications. S-layer proteins and flagellins have been used successfully to study a variety of these modifications, including N-linked glycosylation, signal peptide removal and lipid modification. Use of these well-characterized reporter proteins in the genetically tractable model organisms,Haloferax volcanii, Methanococcus voltaeandMethanococcus maripaludis,has allowed dissection of the pathways and characterization of many of the enzymes responsible for these modifications. Such studies have identified archaeal-specific variations in signal peptidase activity not found in the other domains of life, as well as the enzymes responsible for assembly and biosynthesis of novel N-linked glycans. In vitro assays for some of these enzymes have already been developed. N-linked glycosylation is not essential for eitherHfx. volcaniior theMethanococcusspecies, an observation that allowed researchers to analyze the role played by glycosylation in the function of both S-layers and flagellins, by generating mutants possessing these reporters with only partial attached glycans or lacking glycan altogether. In future studies, it will be possible to consider questions related to the heterogeneity associated with given modifications, such as differential or modulated glycosylation.
Matrix Metalloproteinases and Tissue Inhibitor of Metalloproteinases Are Essential for the Inflammatory Response in Cancer Cells
Authors: Sun Jun
Published: July 2010

Inflammation plays a critical role in the development of cancer. Matrix Metalloproteinase (MMP) functions in the remodeling of the extracellular matrix that is integral for many normal and pathological processes such as morphogenesis, angiogenesis, tissue repair, and tumor invasion. The tissue inhibitor of metalloproteinases (TIMPs) family regulates the activity of multifunctional metalloproteinases. In this paper, we discuss the role and mechanism of MMP and TIMP in regulating inflammation responses in solid tumors. We discuss the mechanism of MMP and inflammation in melanoma, colon cancer, breast cancer, and prostate cancer. We highlight the roles of the TIMP-2 in modulating the proinflammatory NF-κB pathway in melanoma and lung caner cells. Based on the molecular mechanisms of TIMPs and MMPs in inflammation and cancer, we can design new strategies for cancer therapy.
Genetic Polymorphisms of Alcohol Dehydrogenase and Aldehyde Dehydrogenase: Alcohol Use and Type 2 Diabetes in Japanese Men
Authors: Yin Guang , Ohnaka Keizo , Morita Makiko , Tabata Shinji , Tajima Osamu , Kono Suminori
Published: July 2010

This study investigated the association of ADH1B (rs1229984) and ALDH2 (rs671) polymorphisms with glucose tolerance status, as determined by a 75-g oral glucose tolerance test, and effect modification of these polymorphisms on the association between alcohol consumption and glucose intolerance in male officials of the Self-Defense Forces. The study subjects included 1520 men with normal glucose tolerance, 553 with prediabetic condition (impaired fasting glucose and impaired glucose tolerance), and 235 men with type 2 diabetes. There was an evident interaction between alcohol consumption and ADH1B polymorphism in relation to type 2 diabetes (interaction P=.03). The ALDH2487Lys allele was associated with a decreased prevalence odds of type 2 diabetes regardless of alcohol consumption. In conclusion, the ADH1B polymorphism modified the association between alcohol consumption and type 2 diabetes. A positive association between alcohol consumption and type 2 diabetes was confounded by ALDH2 polymorphism.
MR Imaging of Prostate Cancer: Diffusion Weighted Imaging and (3D) Hydrogen 1 (1H) MR Spectroscopy in Comparison with Histology
Authors: Yamamura J. , Salomon G. , Buchert R. , Hohenstein A. , Graessner J. , Huland H. , Graefen M. , Adam G. , Wedegaetner U.
Published: July 2010

Purpose.To evaluate retrospectively the impact of diffusion weighted imaging (DWI) and (3D) hydrogen 1 (1H) MR-spectroscopy (MRS) on the detection of prostatic cancer in comparison to histological examinations.Materials and Methods:50 patients with suspicion of prostate cancer underwent a MRI examination at a 1.5T scanner. The prostate was divided into sextants. Regions of interest were placed in each sextant to evaluate the apparent diffusion coefficient (ADC)-values. The results of the DWI as well as MRS were compared retrospectively with the findings of the histological examination. Sensitivity and specificity of ADC and metabolic ratio (MET)—both separately and in combination—for identification of tumor tissue was computed for variable discrimination thresholds to evaluate its receiver operator characteristic (ROC). An association between ADC, MET and Gleason score was tested by the non-parametric Spearman -test.Results.The average ADC-value was mm2/s 10-3in normal tissue and 0.96±0.24 mm2/s 10-3in tumor tissue (mean 1 SD). MET was in normal tissue and in tumor tissue. The area under the ROC curve was 0.966 (95%-confidence interval 0.941–0.991) and 0.943 (0.918–0.968) for DWI and MRS, respectively. There was a highly significant negative correlation between ADC-value and the Gleason score in the tumor-positive tissue probes (, , ). MRS did not show a significant correlation with the Gleason score (, ). By using both the DWI and MRS, the regression model provided sensitivity and specificity for detection of tumor of 91.9% and 98.3%, respectively.Conclusion.The results of our study showed that both DWI and MRS should be considered as an additional and complementary tool to the T2-weighted MRI for detecting prostate cancer.
Molecular Image Analysis: Quantitative Description and Classification of the Nuclear Lamina in Human Mesenchymal Stem Cells
Authors: Righolt Christiaan H. , Raz Vered , Vermolen Bart J. , Dirks Roeland W. , Tanke Hans J. , Young Ian T.
Published: July 2010

The nuclear lamina is an intermediate filament network that provides a structural framework for the cell nucleus. Changes in lamina structure are found during changes in cell fate such as cell division or cell death and are associated with human diseases. An unbiased method that quantifies changes in lamina shape can provide information on cells undergoing changes in cellular functions. We have developed an image processing methodology that finds and quantifies the 3D structure of the nuclear lamina. We show that measurements on such images can be used for cell classification and provide information concerning protein spatial localization in this structure. To demonstrate the efficacy of this method, we compared the lamina of unmanipulated human mesenchymal stem cells (hMSCs) at passage 4 to cells activated for apoptosis. A statistically significant classification was found between the two populations.
Novel Bone-Targeted Strategies in Oncology
Authors: Vallet Sonia , Smith Matthew R. , Raje Noopur
Published: July 2010

Most patients with bone metastases experience skeletal complications, resulting in significant morbidity and increased risk of death. Although the use of bisphosphonates is a well-established form of supportive care treatment for bone metastasis, complications arising from long-term use require schedule optimization and a search for alternative strategies. Moreover, the scope of use of bone-targeted agents in oncology has widened to include therapy-induced bone loss and antitumor effects. Indeed, bone provides a permissive niche to tumor growth, and targeting the interactions within the bone microenvironment is a promising antitumor strategy. In addition, the pathogenesis of cancer-related bone disease has been partially unraveled with a focus on the anabolic bone compartment, and the rapid bench-to-bedside translation has resulted in the identification of novel therapeutically amenable targets. This review focuses on studies optimizing bisphosphonate use and recent clinical data on denosumab in the treatment of bone disease. We also provide data on trials that have evaluated the antitumor effects of bisphosphonates and summarize the most recent discoveries on the role of the bone niche in cancer development, with insights into the preclinical rationale and clinical assessment of novel antiresorptive and anabolic bone-targeted agents. Clin Cancer Res; 16(16); 4084–93. ©2010 AACR.