bluuebunny/crossref_metadata_2025 huggingface dataset:
Letter from the chair
Authors: Sipior Janice C. , Lending Diane , Amoroso Donald L. , Shayo Conrad , Vowels Susan A.
Published: October 2008

All are welcome to attend ...

"The Eighth Annual ACM-SIGMIS Reception," to be held as an ACM-SIGMIS event prior to the International Conference on Information Systems (ICIS2008) in Paris, France on Saturday, December 13, 2008. Light refreshments will be served.

Where:
International Conference on Information Systems (ICIS2008) Paris, France, Le Palais des Congres, Room not yet assigned

When:
Saturday, December 13, 2008, 5:30 to 7:00 pm

Who:
All ACM-SIGMIS members and their invited guests are welcome

The forthcoming SIGMIS CPR'09 Conference will be held May 28-30 2009 in Limerick, Ireland. Organized and hosted by the University of Limerick, this conference venue is 3 miles from Limerick city centre and 20 miles from Shannon International Airport, with a scenic 300 acre riverside campus. The theme of this year's conference is "New Concepts and Practices in Preparing, Recruiting, and Retaining IS Professionals in the Global Context." Accepted papers will be published by ACM in the refereed conference proceedings which will be distributed at the conference. Additionally, the 2009 conference will include a doctoral student consortium on Thursday, May 28, 2009. An award for best doctoral consortium paper will be presented. For more information, the direct link to the conference website is: http://www.sigmis.org/CPR_2009_Home_Page.htm

Please consider volunteering to serve on the Program Committee for the 2009 conference. Members of the Program Committee serve as reviewers and assist in identifying session chairs and discussants. If you would like to serve on the Program Committee, please contact:
Program Co-chairs:
Jack Downey,
University of Limerick, Ireland
Damien Joseph,
Nanyang Technological University, Singapore
at sigmiscpr2009@easychair.org. If you haven't yet attended ACM-SIGMIS CPR, this year is the year to enjoy the 47th successive conference, only the second meeting to be held outside of the US. Let's continue to make the SIGMIS CPR Conference a success!

As Data Base enters its 40th year of publication, please consider sending your best research to this valued publication outlet. Please submit your manuscript at the Data Base website at: http://the-database.org.

Finally, I would like to encourage you to become an officer of SIGMIS. The Chair of the SIGMIS Nominating Committee is Deb Armstrong,
Florida State University.

The slate of candidates for Chair, Vice Chair, and Secretary/Treasurer is to be sent to ACM headquarters by December 1, 2008. If you would like to run for office, please email the following information to Nominating Committee Chair Deb Armstrong, djarmstrong@fsu.edu:

The office for which you are a candidate

Name

Address (current and future if an address change is expected before elections are completed)

Phone

Email address

ACM Membership Number

Candidate's name as it appears on the ACM Membership Roster

Thank you for your continued support of SIGMIS. Your comments and suggestions are encouraged. Please feel free to contact any one of us.
Nondestructive Reconstruction and Analysis of Solid Oxide Fuel Cell Anodes using X-ray Computed Tomography at sub-50 nm Resolution
Authors: Izzo John R. , Joshi Abhijit , Grew Kyle , Chiu Wilson , Tkachuk Andrei , Wang Siew , Yun Wenbing
Published: October 2008

X-ray computed tomography (XCT) is applied to non-destructively image the three-dimensional (3D) microstructure of a solid oxide fuel cell (SOFC) with a solid yttria-stabilized zirconia (YSZ) electrolyte and porous nickel and YSZ (Ni-YSZ) anode. The x-ray microscope uses the 8 keV Cu-Kα line from a laboratory x-ray source with a condenser optic lens and an objective Fresnel zone plate lens providing spatial resolution of 42.7 nm. The data is visualized as 3D images and post-processed as binary images to obtain structural parameters. Porosity is calculated using a voxel counting method and tortuosity is evaluated by solving the Laplace equation. The 3D representation of the microstructure is used to calculate true structural and transport parameters and optimization through a detailed mass transfer and electrochemical study. Simulation of multi-component mass transport and electrochemical reactions in the microstructure using XCT data as geometric input illustrates the impact of this technique on SOFC modeling.
The Voltammetry and Impedance of Porous Electrodes Correlated by Fourier Transform
Authors: Sedlarikova Marie , Dvorak Petr , Vondrak Jiri
Published: October 2008

Comparison of the apparent capacity evaluated from the charging current on voltammograms and the element of equivalent circuit estimated from impedance spectroscopy was done using Fourier transform. Capacity estimated from the difference between charging and discharging curves is several times higher than the results of impedance spectroscopy. Simplest model based on a constant phase element (C.P.E.) was evaluated Apparent discrepancy is explained in this way.
Kinetic Monte Carlo Simulation of Via Filling: Role of Chloride Ions
Authors: Kaneko Yutaka , Hiwatari Yasuaki , Ohara Katsuhiko , Asa Fujio
Published: October 2008

The influence of chloride ions on the filling process of via holes has been studied with use of a kinetic Monte Carlo method. Four kinds of additives (inhibitors, accelerators, levelers and chloride ions) are included in the solid-by-solid model for crystal growth as a model of copper electrodeposition. It is assumed that the chloride ions are adsorbed on the metal surface and the adsorption of the inhibitors and the accelerators occurs through the interaction with the surface chloride ions. The binding energy of the chloride ions with the accelerators is assumed to be larger than that with the inhibitors. We performed a series of simulations to study the synergistic effects of the chloride ions and the other additives on the film structures. The effect of convection is also taken into account to improve the filling condition. The mechanism of superfilling is discussed from a microscopic point of view.
Nucleation and Growth of Metal Layers under the Influence of a Magnetic Field
Authors: Bund Andreas , Ispas Adriana
Published: October 2008

The effects induced by an external magnetic field with flux densities up to 0.7 T on the nucleation and growth of Ni layers will be discussed here. We will show that both the direction of the superimposed magnetic field and the direction of the natural convection with regard to the electrode surface affect the nucleation and growth processes. The nucleation rates increased considerably when the natural convection and the additional convection generated by the magnetic field acted in the same direction.
Funnel-like Flow Generated Electrochemically in Paramagnetic Media by the Two Paramagnetic Body Forces
Authors: Leventis Nicholas , Chandrasekaran Naveen , Dass Amal , Gao Xuerong
Published: October 2008

We describe a new type of convection in paramagnetic media generated with ferromagnetic electrodes in magnetic fields perpendicular to the electrode surface. That convection mechanism is attributed solely to the paramagnetic body forces F∇B and F∇C and all experimental evidence indicates that the presence of both is important. Based on the direction of the two forces, it is speculated that the solution follows a funnel-like low pattern whereas fresh solution is taken in from the edges of a disk electrode and is expelled out from the center.
Modeling and Numerical Simulation of Magnetic Field Coupled Electrochemical Processes
Authors: Sen Debamoy , Isaac K M , Leventis Nicholas
Published: October 2008

The equations of the electrochemical magnetohydrodynamic problem were numerically solved in a coupled manner for a two-dimensional model problem. Using potentiostatic mode of operation with appropriate boundary conditions, we simulated the interplay of Lorentz forces, convection and concentration distribution under the Butler-Volmer electrode kinetics of a redox couple. The evolution of the flow field over 150 seconds shows the gradual development of a vortex structure. The concentration contours show strong effect of magnetoconvection caused by the Lorentz force.
Chiral Electrode Behaviors of Magnetoelectrodeposited Ag films for Amino Acids
Authors: Mogi Iwao
Published: October 2008

Chiral aspects were investigated in the Ag films electrodeposited under magnetic fields of 2 and 3 T perpendicular to the electrode surface. The films were used as modified electrodes, and cyclic voltammograms were examined for the electrochemical oxidation of cysteine and histidine. In both cases, the chiral aspects were observed as the peak current difference between the enantiomers, and the chirality depended on the polarity of the magnetic field during the electrodeposition. The formation of such chiral films is discussed in connection with the micro-MHD effect.
Caffeine and Theobromine Selectivity using Molecularly Imprinted Polypyrrole Modified Electrodes
Authors: Vinjamuri AnilKiran , Burris Stuart C. , Dahl Darwin
Published: October 2008

Electrochemical detection and quantitation of small- to medium-sized molecules without easily accessible redox potentials is an evolving field that demands combinations of techniques and methods to resolve challenging chemical analysis issues. Solving complex analytical challenges requires at a minimum, techniques that possess specificity, stability and sensitivity. Molecularly imprinted polymers (MIPs) are proving very effective in the development of synthetic recognition systems and are of great interest in the field of electrochemical sensor technology. This study examines the selectivity of caffeine- and theobromine-imprinted polypyrrole electrodes using pulsed amperometric detection (PAD). The selectivity was examined using theobromine and caffeine as competitive analytes. The recognition sites of the respective MIPs appear to possess sufficient binding affinities to enable quantitative determination up to equimolar amounts of competitive analyte. An alternative detection technique using electrochemical impedance spectroscopy is also reported as an alternative to PAD detection.
Cadmium Analysis using Field-Deployable Nanoband Electrode System and Its Removal using Electrocoagulation
Authors: Gomes Jewel A. , Cocke David , Guttula Mallikarjuna , Moreno Hector , Peterson Eric
Published: October 2008

Cadmium (Cd) is an extremely toxic metal commonly found in industrial workplaces. Major industrial releases of Cd are due to waste streams and leaching of landfills, and from a variety of operations that involve Cd or zinc. Particularly, Cd can be released to drinking water from the corrosion of some galvanized plumbing and water main pipe materials. USEPA set Maximum Contaminant Level (MCL) for cadmium at 5 ppb. Long term exposure of Cd above the MCL results in kidney, liver, bone and blood damage. An accurate and rapid measurement of cadmium in the field remains a technical challenge. In this work, a relatively new method of a nanoband electrode system using anodic stripping voltammetry was optimized by changing deposition potential, electrolyte, and plating time. Electrocoagulation was efficiently used to remove Cd from wastewater. Removal mechanism of Cd in electrocoagulation was also proposed with the help of XRD, FTIR, and SEM-EDS.
Carbon Catalyst-Support Corrosion in Polymer Electrolyte Fuel Cells: Mechanistic Insights
Authors: Franco Alejandro A. , Gerard Mathias , Guinard Magalie , Barthe Benoit , Lemaire Olivier
Published: October 2008

In this paper we discuss a novel mechanistic model describing the coupling between the PEFC MEA electro-catalysis and the cathode carbon catalyst-support corrosion. On a physical basis, the model describes the feedback between the instantaneous performance and the intrinsic cathode carbon oxidation process. It allows exploring the impact of the operating conditions and the initial electrodes compositions on the PEFC MEA durability. Some numerical simulations show agreement with experimental knowledge already reported in literature: in particular, when the anode chamber is partially exposed to oxygen (induced by PEM crossover or fuel starvation), cathode thickness decrease and cell potential decay are predicted. Furthermore, we found that cathode damage increases as platinum loading increases and as platinum nano-particles size decreases. On the basis of our modeling approach we propose, and experimentally validate, the use of anodic injection as a way to mitigate cathodic carbon corrosion in in-house elaborated model MEA.
Anodic Stripping Differential Alternative Pulses Voltammetry and Applications
Authors: Zlatev Roumen K. , Stoytcheva Margarita S. , Valdez Benjamin S. , Magnin Jean-Pierre , Velkova Zdravka
Published: October 2008

A modification of the voltammetric technique Differential Alternative Pulses Voltammetry (DAPV) reported by the authors earlier (1) is presented. The potential-time waveform and the signal processing algorithm were properly modified allowing the performance of the DAPV in anodic stripping mode (ASDAPV). These improvements allow its application for trace species determinations in multicomponent solutions without preliminary extraction and separations procedures. Examples of the application of ASDAPV for direct simultaneous determinations of couples of ions having small E1/2 difference as well as for simultaneous multicomponent determinations are presented and discussed.
Study on the Electrochemical Behavior and the Electroanalysis Method of Ethyl Ferulate
Authors: Yu Tingting , He Ping , Liang Yan , Yang Dingming , Jiang Qiying , Zeng Qingyou , Du Licheng , Dong Faqin
Published: October 2008

In this paper, the electrochemical behavior of ethyl ferulate was investigated by cyclic voltammetry on glassy carbon electrode, and a sensitive electroanalytical method was proposed for its determination. It was shown that, in acetate buffer, the electrochemical behavior of ethyl ferulate has a good reversibility, and the currents of cathodic and anodic peaks had linear relativity with the square root of the potential scan rate, showing that ethyl ferulate presents diffusibility. The electron transfer number n and the diffusion coefficient Do were calculated to be 2 and 1.79 × 10-6 cm2 s-1, respectively. Both the cathodic and anodic peak potentials of ethyl ferulate were linearly correlative with pH value of acetate buffer, indicating that proton was involved in the electrochemical process of ethyl ferulate and the numbers of electron transfer and proton were equal. Also, it was observed that both the cathode and anode peak currents are well rectilinear to the concentration of ethyl ferulate in the range of 2.0 ×10-7 to 4.8 × 10-6 mol L-1 (r = 0.9994 and 0.9991, respectively, to the cathode and anode currents, n=8), and the detection limit is 1.0 × 10-7 mol L-1.
Impedance of Porous Electrodes
Authors: Lasia A.
Published: October 2008

Electrochemical impedance spectroscopy might be used to study interfacial processes but it is also sensitive to surface geometry and porosity. Models involving simple pores in the absence and in the presence of electroactive species, in the absence and in the presence of dc current, in the presence of the potential and concentration gradients are presented. Subsequently, models containing distribution of pores and continues porous electrodes are presented.
Impedance of a Disk Electrode with Reactions Involving an Adsorbed Intermediate: Local and Global Analysis
Authors: Wu Shao-Ling , Orazem Mark E. , Vivier Vincent , Tribollet B.
Published: October 2008

The influence of nonuniform current and potential distributions associated with a disk electrode geometry on the impedance response was explored by numerical simulation for Faradaic reactions coupled by an adsorbed intermediate. Consistent with the literature, the associated frequency or time-constant dispersion influenced the impedance response at frequencies above a characteristic value, due to the frequency dependence of the radial distribution of the interfacial potential. The time-constant dispersion was also found to influence the impedance response at low frequencies, due to the potential dependence of the fractional surface coverage of the adsorbed intermediate. The geometry effects were reflected in values for the local Ohmic impedance, which had complex behavior at both high and low frequencies. The dispersion of time constant was described in terms of a local constant-phase element (CPE) that is distributed over the electrode surface and results in a the depression of semicircles in representing the impedance response at low frequencies as well as at high frequencies. A graphical method is described for finding values for the CPE exponent.
Predicting the Long-term Performance of Coating Systems from Short-term EIS Testing
Authors: Taylor S. R. , Hunter Chad N.
Published: October 2008

Barrier property measurements of organic coatings can take long times to assess, can vary significantly in magnitude as a function of sample position, and can change unexpectedly over time. This study uses short-term EIS testing to re-examines the role of the coating-substrate interface in governing long-term coating performance through the use of short-term EIS testing. 32 coating systems comprised of various combinations of chromate and non-chromate conversion coatings, chromate and non-chromated primers, and topcoats on AA2024-T3 substrates were exposed to 0.1M (NH4)2SO4 + 0.005M NaCl for 8 days. A through film defect was made with a diamond-tipped scribe on the 4th day of immersion. Another group panels with these 32 coating systems was exposed to ASTM B117 salt spray for 3000 hours. In a blind comparison, it was determined that the EIS data acquired after the introduction of the defect was essential in the prediction of 3000 h salt spray results. These results show the importance of interfacial information in the prediction of field performance, and provide a promising short-term method for the prediction of long-term performance.
Effect of Large Perturbation Amplitudes on the Impedance Response of an Electrochemical System
Authors: Hirschorn Bryan , Ibrahim Ibrahim , Orazem Mark E. , Takenouti Hisasi , Tribollet B.
Published: October 2008

Numerical simulations of electrochemical systems were used to explore the inﬂuence of large-amplitude potential perturbations on the measured impedance response. The amplitude of the input potential perturbation used for impedance measurements, normally ﬁxed at a value of 10 mV for all systems, should instead be adjusted for each experimental system. Guidelines are developed for selection of appropriate perturbation amplitudes. A characteristic transition frequency is deﬁned that can be used to tailor a frequency-dependent input signal to optimize signal-to-noise levels while maintaining a linear response.
Characterization of Oxide Films by Electrochemical Impedance
Authors: Frateur Isabelle
Published: October 2008

When performing global and local electrochemical impedance measurements with metals or alloys covered by an oxide layer, CPE behavior ascribed to a 3-D normal distribution of an oxide property is often seen in the high-frequency range. Impedance data obtained with Nb anodically polarized in acid fluoride medium (thick oxide layer) and Fe­17Cr stainless steel immersed at OCP in aerated mildly acidic solution (thin oxide layer) were analyzed using the Young model that assumes an exponential decay of the conductivity within the oxide layer. The corresponding Young impedance directly provides the oxide film capacitance from which the oxide film thickness can be estimated. For both thick and thin oxide layers, the Young expression accounts well for the CPE behavior, and the values obtained for the thickness are in good agreement with independent measurements. However, in the case of thin oxide layers, the deduced conductivity profile is not fully satisfactory and new models must be tested.
Guidelines for Evaluation of Error Structure for Impedance Response of Polymer Electrolyte Membrane (PEM) Fuel Cells
Authors: Roy Sunil , Orazem Mark E.
Published: October 2008

Impedance spectroscopy provides the opportunity for in-situ identification and quantification of physical processes in any electrochemical system. However, the impedance response is influenced by instrumental artifacts and non-stationary behavior. General guidelines, based on use of a measurement model, are outlined for estimation of an error structure of impedance measurements. The methodology is applied to estimate error in the impedance response of a Polymer Electrolyte Membrane (PEM) fuel cell. The analysis was used to show that low-frequency inductive loops in impedance response of the fuel cell were, in some cases, fully self consistent, and could therefore be attributed to processes occurring in the fuel cell. The error analysis was also used to improve the sensitivity of the impedance to onset of flooding in the fuel cell.
Electrochemically Grown Metallic Inverse Opals
Authors: Zhu Rong , McLachlan Martyn , McComb David , Ryan Mary
Published: October 2008

3-dimensionally ordered macroporous Cu and Ag were grown using electrodeposition coupled with a colloidal template. The films are homogenous and uniform over a large scale. Optical characterization has confirmed their three-dimensional periodicity and indicated the inverse structures have stop band properties in the visible wavelength range consistent with variation in the effective refractive index of the films.
Comparison of Growth Rate at Oxidation of Si1-xGex Nanowires
Authors: Kim Sang-Yeon , Chang Hyun-Jin , Seong Han-Kyu , Choi Heon-Jin , Ko Dae-Hong
Published: October 2008

The oxidation behaviors of Si1-xGex nanowires were investigated using TEM analysis. Thicker nanowires had higher oxide growth rates. Si1-xGex and silicon nanowires exhibited a saturation tendency as the oxidation time increased. The oxide growth rate of Si1-xGex nanowires was slightly faster than that of silicon nanowires. Differences in germanium content also affect the oxidation behavior.
Fabrication and Characterization of Organic Light-Emitting Diodes using Transparent Single-Crystal-Silicon Membrane
Authors: Lee Su Hwan , Kim Dal Ho , Yang Hee-Doo , Lee Gon-Sub , Park Jea-Gun
Published: October 2008

For organic light-emitting diodes (OLEDs), transparent single-crystal-Si membranes were fabricated on a silicon-on-insulator (SOI) wafer. The SOI wafer included a buried layer of SiO2 and Si3N4 as an etch-stop layer. The etch-stop layer enabled fabrication of transparent single-crystal-Si membranes with various thicknesses, and the thinning technology is described For membranes with thicknesses of 72 and 5000 nm, the respective optical transmittances were 93%, and 9% for R (λ=660 nm), 91%, and 1 % for G (λ=525 nm), and 93%, and 0 % for B (λ=470 nm). Organic light-emitting diodes were then fabricated on transparent single-crystal-Si membranes with various top Si thicknesses. OLEDs with 72 and 5000 nm thick membranes and operating at 8.5 V observed luminance of 2260 and 123 cd/m2, respectively.
Electrochemical Immunoassay Detection of Bacillus Anthracis Protective Antigen
Authors: Aguilar Zoraida , Yoga Narasimhan Padma , Wansapura Chamika , Henrichs Andrea , Aday Julie , Aguilar Ysmael , Estorninos Leo
Published: October 2008

A self-contained microelectrochemical immunoassay detection of Bacillus anthracis protective antigen (PA) has been developed. A microcavity array (VEG4x1{trade mark, serif}) of 50-mm diameter cavities with self-contained microelectrodes were used for the detection of as low as 2.5 pg of B. anthracis Protective Antigen in a less than 12 min total assay time from capture to signal generation. The micro-electrochemical sandwich enzyme-linked immunoassay involved covalent immobilization of the capture antibody on the free end of mercaptoundecanol self-assembled monolayers at the bottom Au-microdisk electrode that also serves as the bottom of the microcavities. Signal generation involved alkaline phosphatase hydrolysis of the enzyme substrate p-aminophenyl phosphate to p-aminophenol that is detected with the wall middle layer gold as the detecting electrode and the top layer gold as the pseudoreference/auxiliary electrodes. The microelectrodes in the cavity exhibited background signals lower than signal for the lowest concentration detected that was 2.5 pg.
Designing Electroactive Biointerface for Spatiotemporal Control of Cell Attachment and Release
Authors: Shah Sunny , Zhu He , Yan Jun , Verkhoturov Stanislav , Revzin Alexander
Published: October 2008

In this paper, we demonstrate the use of individually addressable microelectrodes for cell sorting and cell micropatterning applications. Microelectrodes were modified with cell adhesive or non-adhesive molecules and then electrically stimulated to selectively adsorb or desorb proteins and/or mammalian cells. The switching of the surface properties was achieved by the electrochemical desorption of protein-functionalized thiols and poly(ethylene glycol) PEG silane from gold and indium tin oxide (ITO) electrodes respectively. The thiol surfaces were modified with anti-CD4 antibodies and used to capture T-cells. Upon electrical activation of the microelectrodes, both the antibodies and the T-cells were removed from the specific locations on the substrate. In addition, ITO electrodes were modified with cell- resistive PEG silane which was later electrochemically desorbed to make the surface adhesive to proteins or cells. This technique was employed to pattern two different cell types on the same substrate.
Design and Characterization of Optofluidic Photonic Crystal Structures for the Detection of Fluorescent-Labeled Biomolecules
Authors: Dawson Jeremy M. , Tompkins Randy , Nightingale Josh , Yeldandi Satish , Jo Kyoo , Cao Xian-An , Hornak Lawrence , Korakakis Dimitris , Myers Thomas , Timperman Aaron
Published: October 2008

The combination of optics and microfluidics into optofluidic systems has provided a means of creating portable integrated platforms for performing fluorescence emission analyses in fieldable systems. We present here the design of a photonic crystal transducer for highly sensitive and selective fluorescence-based biomolecule detection using a reduced-size lattice nanocavity tuned for resonance at emission wavelengths. This novel approach to biosensing is based upon photonic crystal defect structures that are engineered to act as waveguides, optical resonant cavities, and nanofluidic flow channels. This paper will discuss modeling, design, and nanofabrication of optofluidic photonic crystal (PhC) transducers in silicon and GaN materials. First-order results of PhC optical property characterization will be provided. Preliminary simulations indicate that fluorescence emission intensity inside of a PhC resonant defect nanocavity is enhanced to a level 26 times greater than emission outside of a defect due to resonant optical confinement and the Purcell effect.
Fabrication of Ultra-Sensitive Carbon Nanotube Field-Effect Sensors (CNTFES) for Biomedical Applications
Authors: Schwalke Udo , Rispal Lorraine
Published: October 2008

In this paper we propose a novel method for the realization of carbon nanotube field-effect sensors (CNTFESs) which will most likely have a strong impact on the next-generation of sensors. CNTFESs are ideally suitable for biomedical sensor applications due to their excellent inherent properties such as ultra small size, high specific surface area and extremely high sensitivity. CNTFESs are based on carbon nanotube field-effect transistors (CNTFETs) which are optimized for sensor applications. We have succeeded to develop a simple, reproducible fabrication process to grow individual single-walled carbon nanotubes (SWNTs) and SWNT-networks directly within the specified device area. No tedious manual manipulation and alignment of the SWNTs is necessary. Electrical results of the fabricated fully functional CNTFETs are presented and the use of these devices as SWNT-based field-effect controlled sensors for virus detection is discussed.
Fibroblast growth factor receptor 1 is a key regulator of early adipogenic events in human preadipocytes
Authors: Widberg C. H. , Newell F. S. , Bachmann A. W. , Ramnoruth S. N. , Spelta M. C. , Whitehead J. P. , Hutley L. J. , Prins J. B.
Published: October 2008

Cell number is an important determinant of adipose tissue mass, and the coordinated proliferation and differentiation of preadipocytes into mature lipid-laden adipocytes underpins the increased adipose tissue mass associated with obesity. Despite this, the molecular cues governing such adipose tissue expansion are poorly understood. We previously reported that fibroblast growth factor-1 (FGF-1) promotes both proliferation and differentiation of human preadipocytes and that the major adipogenic effect of FGF-1 occurs during proliferation, priming the cells for adipose conversion. In the current study, we examined whether this effect was linked to the mitogenic action of FGF-1 by investigating the mitogenic and adipogenic potential of other growth factors, platelet-derived growth factor (PDGF; AA and BB) and vascular endothelial growth factor. Although PDGF-AA and PDGF-BB showed comparable mitogenic potential to FGF-1, only FGF-1 treatment resulted in priming and subsequent differentiation. Pharmacological inhibition of FGF receptor (FGFR) tyrosine kinase activity, using the FGFR-specific inhibitors PD-173074 and SU-5402, revealed an obligate requirement for FGFR activity in these processes. A combination of biochemical and genetic approaches revealed an important role for FGFR1. Knock down of FGFR1 expression by small-interfering RNA reduced FGF-1-stimulated signaling events, proliferation, and priming. Together these data highlight the unique nature of the role of FGF-1 during the earliest stages of adipogenesis and establish a role for FGFR1 in human adipogenesis, identifying FGFR1 as a potential therapeutic target to reduce obesity.
α2-AMPK activity is not essential for an increase in fatty acid oxidation during low-intensity exercise
Authors: Miura Shinji , Kai Yuko , Kamei Yasutomi , Bruce Clinton R. , Kubota Naoto , Febbraio Mark A. , Kadowaki Takashi , Ezaki Osamu
Published: October 2008

A single bout of exercise increases glucose uptake and fatty acid oxidation in skeletal muscle, with a corresponding activation of AMP-activated protein kinase (AMPK). While the exercise-induced increase in glucose uptake is partly due to activation of AMPK, it is unclear whether the increase of fatty acid oxidation is dependent on activation of AMPK. To examine this, transgenic mice were produced expressing a dominant-negative (DN) mutant of α1-AMPK (α1-AMPK-DN) in skeletal muscle and subjected to treadmill running. α1-AMPK-DN mice exhibited a 50% reduction in α1-AMPK activity and almost complete loss of α2-AMPK activity in skeletal muscle compared with wild-type littermates (WT). The fasting-induced decrease in respiratory quotient (RQ) ratio and reduced body weight were similar in both groups. In contrast with WT mice, α1-AMPK-DN mice could not perform high-intensity (30 m/min) treadmill exercise, although their response to low-intensity (10 m/min) treadmill exercise was not compromised. Changes in oxygen consumption and the RQ ratio during sedentary and low-intensity exercise were not different between α1-AMPK-DN and WT. Importantly, at low-intensity exercise, increased fatty acid oxidation in response to exercise in soleus (type I, slow twitch muscle) or extensor digitorum longus muscle (type II, fast twitch muscle) was not impaired in α1-AMPK-DN mice, indicating that α1-AMPK-DN mice utilize fatty acid in the same manner as WT mice during low-intensity exercise. These findings suggest that an increased α2-AMPK activity is not essential for increased skeletal muscle fatty acid oxidation during endurance exercise.
Development of factors to convert frequency to rate for β-cell replication and apoptosis quantified by time-lapse video microscopy and immunohistochemistry
Authors: Saisho Yoshifumi , Manesso Erica , Gurlo Tatyana , Huang Chang-jiang , Toffolo Gianna M. , Cobelli Claudio , Butler Peter C.
Published: October 2008

An obstacle to development of methods to quantify β-cell turnover from pancreas tissue is the lack of conversion factors for the frequency of β-cell replication or apoptosis detected by immunohistochemistry to rates of replication or apoptosis. We addressed this obstacle in islets from 1-mo-old rats by quantifying the relationship between the rate of β-cell replication observed directly by time-lapse video microscopy (TLVM) and the frequency of β-cell replication in the same islets detected by immunohistochemistry using antibodies against Ki67 and insulin in the same islets fixed immediately after TLVM. Similarly, we quantified the rate of β-cell apoptosis by TLVM and then the frequency of apoptosis in the same islets using TdT-mediated dUTP nick-end labeling and insulin. Conversion factors were developed by regression analysis. The conversion factor from Ki67 labeling frequency (%) to actual replication rate (%events/h) is 0.025 ± 0.003 h−1. The conversion factor from TdT-mediated dUTP nick-end labeling frequency (%) to actual apoptosis rate (%events/h) is 0.41 ± 0.05 h−1. These conversion factors will permit development of models to evaluate β-cell turnover in fixed pancreas tissue.
Oxytocin attenuates NADPH-dependent superoxide activity and IL-6 secretion in macrophages and vascular cells
Authors: Szeto Angela , Nation Daniel A. , Mendez Armando J. , Dominguez-Bendala Juan , Brooks Larry G. , Schneiderman Neil , McCabe Philip M.
Published: October 2008

Oxytocin is synthesized and released in the heart and vasculature, tissues that also express oxytocin receptors. Although it has been established this intrinsic cardiovascular oxytocin system is important in normal homeostatic cardiac and vascular regulation, a role for this system in cardiovascular pathophysiology has not been investigated. The current study examined the influence of oxytocin on mechanisms in atherogenesis, oxidative stress, and inflammation in cultured human vascular cells, THP-1 monocytes, and macrophages. Oxytocin receptor protein and mRNA expression, NADPH-dependent superoxide activity, and interleukin-6 secretion were measured. Results demonstrated oxytocin receptor protein and mRNA in THP-1 monocytes and macrophages. Incubation of cells at physiological levels of oxytocin significantly decreased basal and stimulated NADPH-dependent superoxide activity in vascular cells, monocytes, and macrophages by 24–48%. Oxytocin also attenuated interleukin-6 secretion from stimulated THP-1 macrophages and endothelial cells by 56 and 26%, respectively. These findings suggest that oxytocin attenuates vascular oxidative stress and inflammation, two important pathophysiological processes in atherosclerosis. The fact that oxytocin receptors are found in monocytes and macrophages, and oxytocin decreases both superoxide production and release of a proinflammatory cytokine from these cells, suggests a potentially larger role for oxytocin in the attenuation of disease.
Differences in partitioning of meal fatty acids into blood lipid fractions: a comparison of linoleate, oleate, and palmitate
Authors: Hodson Leanne , McQuaid Siobhán E. , Karpe Fredrik , Frayn Keith N. , Fielding Barbara A.
Published: October 2008

There has been much interest in the health effects of dietary fat, but few studies have comprehensively compared the acute metabolic fate of specific fatty acids in vivo. We hypothesized that different classes of fatty acids would be variably partitioned in metabolic pathways and that this would become evident over 24 h. We traced the fate of fatty acids using equal amounts of [U-13C]linoleate, [U-13C]oleate, and [U-13C]palmitate given in a test breakfast meal in 12 healthy subjects. There was a tendency for differences in the concentrations of the tracers in plasma chylomicron-triacylglycerol (TG) (oleate > palmitate > linoleate). This pattern remained in plasma nonesterified fatty acid (NEFA) and very low-density lipoprotein (VLDL)-TG ( P ≤ 0.01 and P ≤ 0.02 for [U-13C]oleate vs. both [U-13C]palmitate and [U-13C]linoleate for NEFA and VLDL-TG, respectively). There was significantly more [U-13C]linoleate than the other two tracers in plasma cholesteryl ester and phospholipid (PL). Using the values for isotopic enrichment in the different lipid fractions compared with the test meal, we calculated the contribution of meal fatty acids to the respective fractions. At 24 h, 10% of plasma PL-linoleate originated from the breakfast test meal. This was significantly greater than for oleate and palmitate (both 3 ± 0.3%; P < 0.05). This pattern was also true for erythrocyte PL fatty acids. The marked rapid incorporation of linoleate from a single meal into blood PL fractions may have functional consequences such as maintenance of membrane fluidity and may explain why linoleate is a useful biomarker of dietary intake.
Dynamic Metabotropic Control of Intrinsic Firing in Cerebellar Unipolar Brush Cells
Authors: Russo Marco J. , Yau Hau-Jie , Nunzi Maria-Grazia , Mugnaini Enrico , Martina Marco
Published: October 2008

Neuronal firing is regulated by the complex interaction of multiple depolarizing and hyperpolarizing currents; intrinsic firing, which defines the neuronal ability to generate action potentials in the absence of synaptic excitation, is particularly sensitive to modulation by currents that are active below the action potential threshold. Cerebellar unipolar brush cells (UBCs) are excitatory granule layer interneurons that are capable of intrinsic firing; here we show that, in acute mouse cerebellar slices, barium-sensitive background potassium channels of UBCs effectively regulate intrinsic firing. We also demonstrate that these channels are regulated by group II metabotropic glutamate receptors (mGluRs), which we show to be present in both of the known subsets of UBCs, one of which expresses calretinin and the other mGluR1α. Finally, we show that background potassium currents controlling UBCs' firing are mediated by at least two channel types, one of which is sensitive and the other insensitive to the GIRK blocker tertiapin. Thus in UBCs, glutamatergic transmission appears to have a complex bimodal effect: although it increases spontaneous firing through activation of ionotropic receptors, it also has inhibitory effects through the mGluR-dependent activation of tertiapin-sensitive and -insensitive background potassium currents.
Some Exact Solutions of Boundary Layer Flows along a Vertical Plate with Buoyancy Forces Combined with Lorentz Forces under Uniform Suction
Authors: Pantokratoras Asterios
Published: October 2008

Exact analytical solutions of boundary layer flows along a vertical porous plate with uniform suction are derived and presented in this paper. The solutions concern the Blasius, Sakiadis, and Blasius‐Sakiadis flows with buoyancy forces combined with either MHD Lorentz or EMHD Lorentz forces. In addition, some exact solutions are presented specifically for water in the temperature range of 0 ∘C ≤ T ≤ 8 ∘C, where water density is nearly parabolic. Except for their use as benchmarking means for testing the numerical solution of the Navier‐Stokes equations, the presented exact solutions with
EMHD forces have use in flow separation control in aeronautics and hydronautics, whereas the MHD results have applications in process metallurgy and fusion technology. These analytical solutions are valid for flows with strong suction.
Analysis of Pyramidal Surface Texturization of Silicon Solar Cells by Molecular Dynamics Simulations
Authors: Chung Hsiao-Yen , Chen Chiun-Hsun , Chu Hsin-Sen
Published: October 2008

The purpose of this paper is to explore the relations between surface texturization and absorptance of multicrystalline silicon solar cells by a simple new model, based on the classic molecular (MD) dynamics simulation, alternative to complex electron‐photon interactions to analyze the surface texturization of solar cells. In this study, the large tilted angle leads to the lower efficiency of solar cell. To consider the effect of incident angle, a range of high efficiency exists due to the increasing probability of second reflection. Furthermore, the azimuth angle of incident light also affects the efficiency of solar cells. Our results agree well with previous studies. This MD model can potentially be used to predict the efficiency promotion in any optical reflection‐absorption cases.
Extracting Moods from Songs and BBC Programs Based on Emotional Context
Authors: Petersen Michael Kai , Butkus Andrius
Published: October 2008

The increasing amounts of media becoming available in converged digital broadcast and mobile broadband networks will require intelligent interfaces capable of personalizing the selection of content. Aiming to capture the mood in the content, we construct a semantic space based on tags, frequently used to describe emotions associated with music in thelast.fmsocial network. Implementing latent semantic analysis (LSA), we model the affective context of songs based on their lyrics, and apply a similar approach to extract moods from BBC synopsis descriptions of TV episodes using TV-Anytime atmosphere terms. Based on our early results, we propose that LSA could be implemented as machinelearning method to extract emotional context and model affective user preferences.
AR Supporting System for Pool Games Using a Camera-Mounted Handheld Display
Authors: Uchiyama Hideaki , Saito Hideo
Published: October 2008

This paper presents a pool supporting system with a camera-mounted handheld display based on augmented reality technology. By using our system, users can get supporting information when they once capture a pool table. They can also watch visual aids through the display while they are capturing the table. First, our system estimates ball positions on the table with one image taken from an arbitrary viewpoint. Next, our system provides several shooting ways considering the next shooting way. Finally, our system presents visual aids such as shooting direction and ball behavior. Main purpose of our system is to estimate and analyze the distribution of balls and to present visual aids. Our system is implemented without special equipment such as a magnetic sensor or artificial markers. For evaluating our system, the accuracy of ball positions and the effectiveness of our supporting information are presented
Cross-Chip Probe Matching Tool: A Web-Based Tool for Linking Microarray Probes within and across Plant Species
Authors: Ghanekar Ruchi , Srinivasasainagendra Vinodh , Page Grier P.
Published: October 2008

The CCPMT is a free, web-based tool that allows plant investigators to rapidly determine if a given gene is present across various microarray platforms, which, of a list of genes, is present on array(s), and which gene a probe or probe set queries and vice versa, and to compare and contrast the gene contents of arrays. The CCPMT also maps a probe or probe sets to a gene or genes within and across species, and permits the mapping of the entire content from one array to another. By using the CCPMT, investigators will have a better understanding of the contents of arrays, a better ability to link data between experiments, ability to conduct meta-analysis and combine datasets, and an increased ability to conduct data mining projects.
The Fisher Information Matrix as a Relevant Tool for Sensor Selection in Engine Health Monitoring
Authors: Borguet S. , Léonard O.
Published: October 2008

Engine health monitoring has been an area of intensive research for many years. Numerous methods
have been developed with the goal of determining a faithful picture of the engine condition. On the
other hand, the issue of sensor selection allowing an efficient diagnosis has received less attention
from the community. The present contribution revisits the problem of sensor selection for engine
performance monitoring within the scope of information theory. To this end, a metric that integrates
the essential elements of the sensor selection problem is defined from the Fisher information matrix. An example application consisting in a commercial turbofan engine illustrates the enhancement that can be expected from a wise selection of the sensor set.
Sampling Uncertainty and Confidence Intervals for the Brier Score and Brier Skill Score
Authors: Bradley A. Allen , Schwartz Stuart S. , Hashino Tempei
Published: October 2008

For probability forecasts, the Brier score and Brier skill score are commonly used verification measures of forecast accuracy and skill. Using sampling theory, analytical expressions are derived to estimate their sampling uncertainties. The Brier score is an unbiased estimator of the accuracy, and an exact expression defines its sampling variance. The Brier skill score (with climatology as a reference forecast) is a biased estimator, and approximations are needed to estimate its bias and sampling variance. The uncertainty estimators depend only on the moments of the forecasts and observations, so it is easy to routinely compute them at the same time as the Brier score and skill score. The resulting uncertainty estimates can be used to construct error bars or confidence intervals for the verification measures, or perform hypothesis testing.

Monte Carlo experiments using synthetic forecasting examples illustrate the performance of the expressions. In general, the estimates provide very reliable information on uncertainty. However, the quality of an estimate depends on both the sample size and the occurrence frequency of the forecast event. The examples also illustrate that with infrequently occurring events, verification sample sizes of a few hundred forecast–observation pairs are needed to establish that a forecast is skillful because of the large uncertainties that exist.
The Atlantic Multidecadal Oscillation Inferred from the Forced Climate Response in Coupled General Circulation Models
Authors: Knight Jeff R.
Published: October 2008

Instrumental sea surface temperature records in the North Atlantic Ocean are characterized by large multidecadal variability known as the Atlantic multidecadal oscillation (AMO). The lack of strong oscillatory forcing of the climate system at multidecadal time scales and the results of long unforced climate simulations have led to the widespread, although not ubiquitous, view that the AMO is an internal mode of climate variability. Here, a more objective examination of this hypothesis is performed using simulations with natural and anthropogenic forcings from the Coupled Model Intercomparison Project phase 3 (CMIP3) database. Ensemble means derived from these data allow an estimate of the response of models to forcings, as averaging leads to cancellation of the internal variability between ensemble members. In general, the means of individual model ensembles appear to be inconsistent with observed temperatures, although small ensemble sizes result in uncertainty in this conclusion. Combining the ensembles from different models creates a multimodel ensemble of sufficient size to allow for a good estimate of the forced response. This shows that the variability in observed North Atlantic temperatures possess a clearly distinct signature to the climate response expected from forcings. The reliability of this finding is confirmed by sampling those models with low decadal internal variability and by comparing simulated and observed trends. In contrast to the inconsistency with the ensemble mean, the observations are consistent with the spread of responses in the ensemble members, suggesting they can be accounted for by the combined effects of forcings and internal variability. In the most recent period, the results suggest that the North Atlantic is warming faster than expected, and that the AMO entered a positive phase in the 1990s. The differences found between observed and ensemble mean temperatures could arise through errors in the observational data, errors in the models’ response to forcings or in the forcings themselves, or as a result of genuine internal variability. Each of these possibilities is discussed, and it is concluded that internal variability within the natural climate system is the most likely origin of the differences. Finally, the estimate of internal variability obtained using the model-derived ensemble mean is proposed as a new way of defining the AMO, which has important advantages over previous definitions.