bluuebunny/crossref_metadata_2025 huggingface dataset:
A SIMPLE HAMILTONIAN MODEL OF RUNAWAY PARTICLE WITH SINGULAR INTERACTION
Authors: BUTTÀ PAOLO , MANZO FRANCESCO , MARCHIORO CARLO
Published: May 2005

We consider a Hamiltonian system given by a charged particle under the action of a constant electric field and interacting with a medium, which is described as a Vlasov fluid. We assume that the action of the charged particle on the fluid is negligible and that the latter has one-dimensional symmetry. We prove that if the singularity of the particle/medium interaction is integrable and the electric field intensity is large enough, then the particle escapes to infinity with a quasi-uniformly accelerated motion. A key tool in the proof is a new estimate on the growth in time of the fluid particle velocity for one-dimensional Vlasov fluids with bounded interactions.
HYDRODYNAMIC LIMIT FOR THE VLASOV–POISSON–FOKKER–PLANCK SYSTEM: ANALYSIS OF THE TWO-DIMENSIONAL CASE
Authors: GOUDON THIERRY
Published: May 2005

We consider the hydrodynamic limit for the VPFP system in dimension two, dealing with general initial data having finite mass, energy and entropy. The limit equation consists in a drift-diffusion equation, where the drift velocity is defined by means of the Poisson relation. Our result is twofold. In the case of repulsive (electrostatic) forces, we prove the convergence globally in time in a weak L1 setting. Considering attractive (gravitational) forces, the same result applies provided a certain scaling parameter is large enough. This is precisely the assumption which prevents the formation of Dirac masses in finite time in the limit equations, as recently shown by Dolbeault–Perthame.
NITROGEN DOPING IN CAMPHORIC CARBON FILMS AND ITS APPLICATION TO PHOTOVOLTAIC CELL
Authors: RUSOP M. , MOMINUZZAMAN M. , SOGA T. , JIMBO T. , UMENO M.
Published: May 2005

Carbon films have been deposited on quartz and single-crystal silicon substrates by pulsed laser deposition technique. The soot for the target was obtained from burning camphor, a natural source. The effect of nitrogen (N) incorporation in camphoric carbon film is investigated. Optical gap for the undoped film is about 0.95 eV. The optical gap remains unchanged for low N content and decreases to about 0.7 eV. With higher N content, the optical gap increases. The resistivity of the carbon film increases with N content, initially and decreases with higher N content up till the film that is deposited at 30 mTorr. The results indicate successful doping for the film deposited at low nitrogen content. The J–V characteristics of N-incorporated carbon/silicon photovoltaic cells under illumination are observed to improve upon N-incorporation in the carbon layer.
CHARACTERISTICS OF PHOSPHORUS-DOPED AMORPHOUS CARBON FILMS GROWN BY R. F. PLASMA-ENHANCED CVD WITH A NOVEL PHOSPHORUS SOLID TARGET
Authors: RUSOP M. , ADACHI M. , SOGA T. , JIMBO T.
Published: May 2005

Phosphorus-doped amorphous carbon (n-C:P) films were grown by r. f.-power-assisted plasma-enhanced chemical vapor deposition at room temperature using a novel solid red phosphorus target. The influence of phosphorus doping on material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, the solar cell properties such as series resistance, short circuit current density, open circuit current voltage, fill factor and conversion efficiency along with the spectral response are reported for the fabricated carbon-based n-C:P/p-Si heterojunction solar cell that was measured by standard measurement technique. The cells performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm 2, 25°C). The maximum of open-circuit voltage (V oc ) and short-circuit current density (J sc ) for the cells are observed to be approximately 236 V and 7.34, mAcm 2 respectively for the n-C:P/p-Si cell grown at lower r. f. power of 100 W. The highest energy conversion efficiency (η) and fill factor (FF) were found to be approximately 0.84% and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.
CRACKING BEHAVIOR OF CERAMIC PARTICLES REINFORCED NI-BASE ALLOYS COMPOSITE COATING BY LASER CLADDING
Authors: ZHANG WEIPING , LIU SHUO
Published: May 2005

In-situ synthesized TiB2 particles reinforced Ni-base composite coatings with different compositions were fabricated on medium carbon steel using laser cladding. Cracking behavior in different coatings was studied by microanalysis. Results show that the coating quality is good with optimal laser parameters and coating compositions; whereas the cracks formed in the coating with high content of ceramic phases mainly include the following: the transcrystalline cracks in the bonding metal matrix, the high density cracks in the edge of the coating, micro-cracks on the interface of the matrix and the hardy ceramic phases and in the vicinity of the bonding interface in the heat-affected zone etc. Cracking behavior in the coating is mainly attributed to the thermal stress induced by the difference of the thermal expansion coefficient of the coating materials and the metal matrix, and the phase transformation stress plays an important role too.
PHYSICAL PROPERTIES OF AU AND AL THIN FILMS MEASURED BY RESISTIVE HEATING
Authors: AVILÉS F. , CEH O. , OLIVA A. I.
Published: May 2005

The electrical resistivity (ρ), resistive thermal coefficient (αr), thermal expansion coefficient (αt) and stress (σ) of Al and Au thin films deposited by thermal evaporation were measured while films were heated by Joule effect. Electrical resistivity measured by the four-probe technique was simultaneously measured with surface film temperature in real time. Au films show important variations in the αr and ρ properties when thickness ranged from 0.1μm to 1μm; contrarily, Al films show insignificant variations in the 0.1μm to 2γm thickness range. The role of the surface aluminum oxide on these measurements and the intrinsic stress on films determined with grazing incidence X-rays are discussed.
THE STABILITY OF LIQUID EVAPORATION EQUILIBRIUM
Authors: ZHANG SHIMIN
Published: May 2005

For the evaporation of the pure liquid under the condition of constant temperature and constant external pressure, the phase equilibrium of the liquid vapor in the bubble and the liquid outside the bubble is always a kind of stable equilibrium whether there is air or not in the bubble. If there is no air in the bubble, the bubble and liquid cannot coexist in the mechanical equilibrium when the vapor pressure of the liquid in the bubble is less than or equal to the external pressure; the bubble and liquid can coexist in an unstable equilibrium of mechanics when the vapor pressure of the liquid is greater than the external pressure. If there is air in the bubble, the bubble and liquid can coexist in a stable equilibrium of mechanics when the vapor pressure of the liquid is less than or equal to the external pressure; the bubble and liquid can coexist in a stable and an unstable equilibrium of mechanics when the vapor pressure of the liquid is greater than the external pressure and less than a certain pressure pm; the bubble and liquid cannot coexist in the mechanical equilibrium when the vapor pressure of the liquid is equal to or greater than pm.
THE MEAN WORK FUNCTION EFFECTIVE FOR POSITIVE ION EMISSION FROM POLY- AND MONOCRYSTALLINE SURFACES
Authors: KAWANO HIROYUKI
Published: May 2005

To clarify the thermionic property of solids, the mean work function effective for positive ion from polycrystalline surfaces (ϕ+) is theoretically studied together with that for electron emission (ϕe). The theoretical values of ϕ+ and ϕe thus evaluated typically with W are in good agreement respectively with those experimental ones accepted today. The thermionic contrast (Δϕ* ≡ ϕ+ – ϕe) is determined to be 0.56–0.57eV for W. For other polycrystalline metals (Nb, Mo, Ta, Re, Ir and Pt), it ranges from about 0.4 to 0.8eV in contrast with monocrystalline ones having Δϕ* = 0. Consequently, the fact of Δϕ* > 0 should be taken into consideration with any polycrystalline surface, and ϕ+ should be adopted whenever we try to analyze those data on positive ion emission due to any of the processes such as thermal stimulation and ion bombardment at heterogeneous surfaces. This article concludes that such typical data on thermal- and secondary-positive ion emissions are analyzed reasonably by adoption of ϕ+ instead of ϕe.
LASER SURFACE MODIFICATION OF TITANIUM ALLOYS — A REVIEW
Authors: TIAN Y. S. , CHEN C. Z. , WANG D. Y. , LEI T. Q.
Published: May 2005

Recent developments of laser surface modification of titanium alloys for increasing their corrosion, wear and oxidation resistance are introduced. The effects of laser processing parameters on the resulting surface properties of titanium alloys are reviewed. The problems to be solved and the prospects in the field of laser modification of Ti alloys are discussed. Due to the intrinsic properties, a laser beam can be focused onto the metallic surface to produce a broad range of treatments depending on the input energy. Thus, composite strengthening coatings can be fabricated by the methods of laser alloying, cladding, pulse laser deposition (PLD), etc., which are promising techniques of producing a layer of new materials on the surface of titanium alloys.
INFLATION REGIMES AND PRICE-SETTING INTERACTIONS
Authors: GAFFEO EDOARDO
Published: May 2005

A large body of empirical work is clear-cut in suggesting that the international post-war inflation experience may be described in terms of switches among multiple regimes. A definite explanation of this stylized fact, however, is still under debate. In this paper, we model an economy composed of a large number of interacting price-setting firms which can replicate the evidence at hand. Interactions emerge as a by-product of consumers' uncertainty on the prices charged by different firms. The underlying Markovian structure possesses a stationary distribution with multiple modes, so that its associated dynamics is characterized by multiple regimes and sudden transitions among them. In particular, for any (almost-fully accommodating) monetary policy reaction function, the existence of a multiplicity of inflation regimes is associated to the information acquisition technology consumers have in searching for the lowest price.
LONG MEMORY STOCHASTIC VOLATILITY IN OPTION PRICING
Authors: FEDOTOV SERGEI , TAN ABBY
Published: May 2005

The aim of this paper is to present a stochastic model that accounts for the effects of a long-memory in volatility on option pricing. The starting point is the stochastic Black–Scholes equation involving volatility with long-range dependence. We define the stochastic option price as a sum of classical Black–Scholes price and random deviation describing the risk from the random volatility. By using the fact that the option price and random volatility change on different time scales, we derive the asymptotic equation for this deviation involving fractional Brownian motion. The solution to this equation allows us to find the pricing bands for options.
ARBITRAGE IN FRACTAL MODULATED BLACK–SCHOLES MODELS WHEN THE VOLATILITY IS STOCHASTIC
Authors: BAYRAKTAR ERHAN , POOR H. VINCENT
Published: May 2005

In this paper an arbitrage strategy is constructed for the modified Black–Scholes model driven by fractional Brownian motion or by a time changed fractional Brownian motion, when the volatility is stochastic. This latter property allows the heavy tailedness of the log returns of the stock prices to be also accounted for in addition to the long range dependence introduced by the fractional Brownian motion. Work has been done previously on this problem for the case with constant "volatility" and without a time change; here these results are extended to the case of stochastic volatility models when the modulator is fractional Brownian motion or a time change of it. (Volatility in fractional Black–Scholes models does not carry the same meaning as in the classic Black–Scholes framework, which is made clear in the text.) Since fractional Brownian motion is not a semi-martingale, the Black–Scholes differential equation is not well-defined sense for arbitrary predictable volatility processes. However, it is shown here that any almost surely continuous and adapted process having zero quadratic variation can act as an integrator over functions of the integrator and over the family of continuous adapted semi-martingales. Moreover it is shown that the integral also has zero quadratic variation, and therefore that the integral itself can be an integrator. This property of the integral is crucial in developing the arbitrage strategy. Since fractional Brownian motion and a time change of fractional Brownian motion have zero quadratic variation, these results are applicable to these cases in particular. The appropriateness of fractional Brownian motion as a means of modeling stock price returns is discussed as well.
PRICING CREDIT RISK OF ASSET-BACKED SECURITIZATION BONDS IN SINGAPORE
Authors: SING TIEN FOO , ONG SEOW ENG , FAN GANG-ZHI , LIM KIAN GUAN
Published: May 2005

Asset-backed securitization (ABS) is a creative arrangement to raise funds through the issuance of marketable securities backed by predictable future cash flows from revenue-producing assets. This paper proposes two pricing models: structural model and intensity model, to value credit spreads on Singapore ABS bonds. Sensitivity analyses were conducted on the ABS credit spreads by varying the values of the key input variables within a plausible range. The property price volatility and its correlations with risk-less interest rates have been shown to have positive effects on the ABS credit spreads. However, when the market volatility is extremely high, the credit spreads decrease with an increase in the time to maturity. The positive effects of the property price volatility were significantly reduced when credit enhancements were added to the ABS bonds, and the credit risks associated with the correlation variable were fully eliminated in the credit enhanced ABS bonds. The rate of loss recovery in the event of default also has significant impact on the credit risks of the ABS bonds. ABS bonds backed by physical property will likely to have high recovery rates thus reducing the credit risks vis-à-vis non-collateralized bonds.
BLOW-UP ANALYSIS FOR LIOUVILLE TYPE EQUATION IN SELF-DUAL GAUGE FIELD THEORIES
Authors: OHTSUKA HIROSHI , SUZUKI TAKASHI
Published: May 2005

We study the asymptotic behavior of the solution sequence of Liouville type equations observed in various self-dual gauge field theories. First, we show that such a sequence converges to a measure with a singular part that consists of Dirac measures if it is not compact in W1,2. Then, under an additional condition, the singular limit is specified by the method of symmetrization of the Green function.
SHARP ASYMPTOTIC BEHAVIOR OF SOLUTIONS TO NONLINEAR SCHRÖDINGER EQUATIONS WITH REPULSIVE INTERACTIONS
Authors: KITA NAOYASU , OZAWA TOHRU
Published: May 2005

A detailed description is given on the large time behavior of scattering solutions to the Cauchy problem for nonlinear Schrödinger equations with repulsive interactions in the short-range case without smallness condition on the data.
VERSAL DEFORMATIONS OF THREE-DIMENSIONAL LIE ALGEBRAS AS L∞ALGEBRAS
Authors: FIALOWSKI ALICE , PENKAVA MICHAEL
Published: May 2005

We consider versal deformations of 0|3-dimensional L∞algebras, also called strongly homotopy Lie algebras, which correspond precisely to ordinary (non-graded) three-dimensional Lie algebras. The classification of such algebras is well-known, although we shall give a derivation of this classification using an approach of treating them as L∞algebras. Because the symmetric algebra of a three-dimensional odd vector space contains terms only of exterior degree less than or equal to three, the construction of versal deformations can be carried out completely. We give a characterization of the moduli space of Lie algebras using deformation theory as a guide to understanding the picture.
ON THE LOCATION OF SPIKES FOR THE SCHRÖDINGER EQUATION WITH ELECTROMAGNETIC FIELD
Authors: SECCHI SIMONE , SQUASSINA MARCO
Published: May 2005

We consider the standing wave solutions of the three dimensional semilinear Schrödinger equation with competing potential functions V and K and under the action of an external electromagnetic field B. We establish some necessary conditions for a sequence of such solutions to concentrate, in two different senses, around a given point. In the particular but important case of nonlinearities of power type, the spikes locate at the critical points of a smooth ground energy map independent of B.
ON ELECTRONIC SHELLS SURROUNDING CHARGED INSULATED METALLIC CLUSTERS
Authors: DIETRICH K. , GARNY M. , POMORSKI K.
Published: May 2005

We determine the wavefunctions of electrons bound to a positively charged mesoscopic metallic cluster covered by an insulating surface layer. The radius of the metal core and the thickness of the insulating surface layer are of the order of a couple of Ångström. We study, in particular, the electromagnetic decay of externally located electrons into unoccupied internally located states that exhibit a resonance behavior. This resonance structure has the consequence that the lifetime of the "mesoscopic atoms" may vary by up to six orders of magnitude depending on the values of the parameters (from seconds to years).
MANUFACTURING AND CHARACTERIZATION OF CARBON NANOTUBE/POLYETHYLENE COMPOSITES
Authors: MAHFUZ HASSAN , ADNAN ASHFAQ , RANGARI VIJAYA K. , JEELANI SHAIK
Published: May 2005

The present study describes a method to fabricate polymer matrix nanocomposites by reinforcing multi-walled carbon nanotubes through an extrusion process. Linear low density polyethylene (LLDPE) powder and multi-walled carbon nanotubes (CNTs) are first dry mixed and extruded in the form of filaments by a single screw extrusion process. After extrusion, the filament is partially cooled by chilled air, dried, and continuously wound in a spool. The filaments are then laid in roving, stacked in a unidirectional fashion, and consolidated in a compression molding machine to come up with laminated composites. Thermo gravimetric analysis (TGA) has been performed to compare the thermal stability of as-fabricated composites with the neat polymer. The TGA result shows that the extruded composites are thermally more stable than their neat counterparts. The crystalline nature of CNTs and of as-fabricated composites were identified by X-ray diffraction (XRD) studies. The XRD results indicate that the nanocomposite materials are more crystalline than the neat systems, and the differential scanning calorimetry studies also confirmed the same trend. The scanning electron microscopy result showed that the sizes of extruded neat and nanophased filaments were about 117 and 73 μm, respectively. Tensile coupons from the consolidated panels were then extracted both in longitudinal (0°) and in transverse (90°) directions and tested in a Minimat Tester. It was found that with the addition of 2% by weight of CNTs in LLDPE, the tensile strength and modulus of the composite has increased by about 34 and 38%, respectively. The (0°) and (90°) coupons have also demonstrated that there are directional effects in the tensile response, which is believed to have been caused by the alignment of CNTs during the extrusion process. It is our understanding that such improvement in properties is because of the increase in crystallinity of the polymer due to CNT infusion, and also due to the alignment of CNTs in the extrusion direction in the nanocomposites. Details of the fabrication procedures, synthesis of composites, and mechanical testing are included in the paper.
SOLUBLE CARBON NANOTUBES: FUNDAMENTALS AND APPLICATIONS
Authors: NAKASHIMA NAOTOSHI
Published: May 2005

Carbon nanotubes (CNTs) have been in the forefront of nanoscience and nanotechnology because of their remarkable electronic, mechanical, and thermal properties and specific functions. CNTs have high potentials for possible applications in the fields of energy, electronics, IT, and materials. However, because of the insolubility of the nanotubes in solvents, chemical, biochemical, and biological (medical) approaches using these materials have been rather limited. Soluble CNTs in aqueous and organic systems are of interests since they may open the door in such fields. In this review article, (i) the dissolution of CNTs in water and in organic solvents by using chemical modification and physical adsorption and their applications to chemical and biological areas, (ii) separation of metallic SWNTs and semiconducting SWNTs by the combination of individual dissolution of SWNTs and the selective chemical modification, (iii) the preparation of nanotube films and fibers from dissolved/dispersed SWNTs in aqueous micelles, and (iv) CNT liquid crystal formation are summarized.
TRANSITION METAL/CARBON NANOTUBE HYBRID STRUCTURES
Authors: YANG CHIH-KAI , ZHAO JIJUN , LU JIAN PING
Published: May 2005

The unique geometry of carbon nanotubes offers an ideal template for designing one-dimensional metal/nanotube hybrid structures. Through ab initio calculations we found that transition-metal/nanotube hybrid structures exhibit very interesting physical properties. The hybrid structures can have drastically different conduction properties from those of the pristine tubes and considerable magnetic moments. In some instances perfect spin polarization is achieved. The results point to a new and promising approach that uses such hybrid structures as devices for spin-polarized transport, which is expected to provide immense applications in the emerging field of spintronics.
Food deprivation differentially modulates orexin receptor expression and signaling in rat hypothalamus and adrenal cortex
Authors: Karteris Emmanouil , Machado Rachel J. , Chen Jing , Zervou Sevasti , Hillhouse Edward W. , Randeva Harpal S.
Published: May 2005

Although starvation-induced biochemical and metabolic changes are perceived by the hypothalamus, the adrenal gland plays a key role in the integration of metabolic activity and energy balance, implicating feeding as a major synchronizer of rhythms in the hypothalamic-pituitary-adrenal (HPA) axis. Given that orexins are involved in regulating food intake and activating the HPA axis, we hypothesized that food deprivation, an acute challenge to the systems that regulate energy balance, should elicit changes in orexin receptor signaling at the hypothalamic and adrenal levels. Food deprivation induced orexin type 1 (OX1R) and 2 (OX2R) receptors at mRNA and protein levels in the hypothalamus, in addition to a fivefold increase in prepro-orexin mRNA. Cleaved peptides OR-A and OR-B are also elevated at the protein level. Interestingly, adrenal OX1R and OX2R levels were significantly reduced in food-deprived animals, whereas there was no expression of prepro-orexin in the adrenal gland in either state. Food deprivation exerted a differential effect on OXR-G protein coupling. In the hypothalamus of food deprived rats compared with controls, a significant increase in coupling of orexin receptors to Gq, Gs, and Go was demonstrated, whereas coupling to Gi was relatively less. However, in the adrenal cortex of the food-deprived animal, there was decreased coupling of orexin receptors to Gs, Go, and Gq and increased coupling to Gi. Subsequent second-messenger studies (cAMP/IP3) have supported these findings. Our data indicate that food deprivation has differential effects on orexin receptor expression and their signaling characteristics at the hypothalamic and adrenocortical levels. These findings suggest orexins as potential metabolic regulators within the HPA axis both centrally and peripherally.
Sensory nerve inactivation by resiniferatoxin improves insulin sensitivity in male obese Zucker rats
Authors: Moesgaard Sophia G. , Brand Christian L. , Sturis Jeppe , Ahrén Bo , Wilken Michael , Fleckner Jan , Carr Richard D. , Svendsen Ove , Hansen Anker J. , Gram Dorte X.
Published: May 2005

Recent studies have suggested that sensory nerves may influence insulin secretion and action. The present study investigated the effects of resiniferatoxin (RTX) inactivation of sensory nerves (desensitization) on oral glucose tolerance, insulin secretion and whole body insulin sensitivity in the glucose intolerant, hyperinsulinemic, and insulin-resistant obese Zucker rat. After RTX treatment (0.05 mg/kg RTX sc given at ages 8, 10, and 12 wk), fasting plasma insulin was reduced ( P < 0.0005), and oral glucose tolerance was improved ( P < 0.005). Pancreas perfusion showed that baseline insulin secretion (7 mM glucose) was lower in RTX-treated rats ( P = 0.01). Insulin secretory responsiveness to 20 mM glucose was enhanced in the perfused pancreas of RTX-treated rats ( P < 0.005) but unaffected in stimulated, isolated pancreatic islets. At the peak of spontaneous insulin resistance in the obese Zucker rat, insulin sensitivity was substantially improved after RTX treatment, as evidenced by higher glucose infusion rates (GIR) required to maintain euglycemia during a hyperinsulinemic euglycemic (5 mU·kg−1·min−1) clamp (GIR60–120min: 5.97 ± 0.62 vs. 11.65 ± 0.83 mg·kg−1·min−1 in RTX-treated rats, P = 0.003). In conclusion, RTX treatment and, hence, sensory nerve desensitization of adult male obese Zucker rats improved oral glucose tolerance by enhancing insulin secretion, and, in particular, by improving insulin sensitivity.
Multiphoton imaging of renal tissues in vitro
Authors: Peti-Peterdi János
Published: May 2005

The highly inhomogeneous and light-scattering structure of living renal tissue makes the application of conventional imaging techniques more difficult compared with other parenchymal organs. On the other hand, key physiological processes of the kidney, such as regulation of glomerular filtration, hemodynamics, concentration, and dilution, involve complex interactions between multiple cell types and otherwise inaccessible structures that necessitate visual approaches. An ideal solution is multiphoton excitation fluorescence microscopy, a state-of-the-art imaging technique superior for deep optical sectioning of living tissue samples. Here, we review the basics and advantages of multiphoton microscopy and provide examples for its application in renal physiology using dissected cortical and medullary tissues in vitro. In combination with microperfusion techniques, the major functions of the juxtaglomerular apparatus, tubuloglomerular feedback and renin release, can be studied with high spatial and temporal resolution. Salt-dependent changes in macula densa cell volume, vasoconstriction of the afferent arteriole, and activity of an intraglomerular precapillary sphincter composed of renin granular cells are visualized in real time. Release and tissue activity of renin can be studied on the individual granule level. Imaging of the living inner medulla shows how interstitial cells interconnect cells of the vasa recta, loop of Henle, and collecting duct. In summary, multiphoton microscopy is an exciting new optical sectioning technique that has great potential for numerous future developments and is ideal for applications that require deep optical sectioning of living tissue samples.
Intravital multiphoton microscopy of dynamic renal processes
Authors: Molitoris Bruce A. , Sandoval Ruben M.
Published: May 2005

Recent advances in microscopy and optics, computer sciences, and the available fluorophores used to label molecules of interest have empowered investigators to utilize intravital two-photon microscopy to study the dynamic events within the functioning kidney. This emerging technique enables investigators to follow functional and structural alterations with subcellular resolution within the same field of view over seconds to weeks. This approach invigorates the validity of data and facilitates analysis and interpretation as trends are more readily determined when one is more closely monitoring indicative physiological parameters. Therefore, in this review we emphasize how specific approaches will enable studies into glomerular permeability, proximal tubule endocytosis, and microvascular function within the kidney. We attempt to show how visual data can be quantified, thus allowing enhanced understanding of the process under study. Finally, emphasis is given to the possible future opportunities of this technology and its present limitations.
Synaptic Depression as a Timing Device
Authors: Grande Lucinda A. , Spain William J.
Published: May 2005

A depressing synapse transforms a time interval into a voltage amplitude. The effect of that transformation on the output of the neuron and network depends on the kinetics of synaptic depression and properties of the postsynaptic neuron and network. Using as examples neural circuits that incorporate depressing synapses, we show how short-term depression can contribute to a surprising variety of time-dependent computational and behavioral tasks.
Transgenic and Knockout Mice in Diabetes Research: Novel Insights into Pathophysiology, Limitations, and Perspectives
Authors: Plum L. , Wunderlich F. T. , Baudler S. , Krone W. , Brüning J. C.
Published: May 2005

Insulin resistance and type 2 diabetes are serious public health threats. Although enormous research efforts have been focused on the pathogenesis of these diseases, the underlying mechanisms remain only partly understood. Here we review mouse phenotypes resulting from inactivation of molecules responsible for the control of glucose metabolism that have led to novel insights into insulin action and the development of insulin resistance. In addition, more sophisticated strategies to manipulate genes in mice in the future are presented.
Functional genomic characterization of delipidation elicited bytrans-10,cis-12-conjugated linoleic acid (t10c12-CLA) in a polygenic obese line of mice
Authors: House Ralph L. , Cassady Joseph P. , Eisen Eugene J. , Eling Thomas E. , Collins Jennifer B. , Grissom Sherry F. , Odle Jack
Published: May 2005

Gene expression was measured during t10c12-CLA-induced body fat reduction in a polygenic obese line of mice. Adult mice ( n = 185) were allotted to a 2 × 2 factorial experiment consisting of either nonobese (ICR-control) or obese (M16-selected) mice fed a 7% fat, purified diet containing either 1% linoleic acid (LA) or 1% t10c12-CLA. Body weight (BW) by day 14 was 12% lower in CLA- compared with LA-fed mice ( P < 0.0001). By day 14, t10c12-CLA reduced weights of epididymal, mesenteric, and brown adipose tissues, as a percentage of BW, in both lines by 30, 27, and 58%, respectively, and increased liver weight/BW by 34% ( P < 0.0001). Total RNA was isolated and pooled (4 pools per tissue per day) from epididymal adipose ( days 5 and 14) of the obese mice to analyze gene expression profiles using Agilent mouse oligo microarray slides representing >20,000 genes. Numbers of genes differentially expressed by greater than or equal to twofold in epididymal adipose ( days 5 and 14) were 29 and 125, respectively. It was concluded that, in adipose tissue, CLA increased expression of uncoupling proteins (1 and 2), carnitine palmitoyltransferase system, tumor necrosis factor-α ( P < 0.05), and caspase-3 but decreased expression of peroxisome proliferator-activated receptor-γ, glucose transporter-4, perilipin, caveolin-1, adiponectin, resistin, and Bcl-2 ( P < 0.01). In conclusion, this experiment has revealed candidate genes that will be useful in elucidating mechanisms of adipose delipidation.
Peptide-Mediated Protection from Ethanol-Induced Neural Tube Defects
Authors: Chen Shao-Yu , Charness Michael E. , Wilkemeyer Michael F. , Sulik Kathleen K.
Published: May 2005

Ethanol inhibition of L1-mediated cell adhesion may contribute to the spectrum of neurological, behavioral and morphological abnormalities associated with prenatal ethanol exposure. We showed previously that the neuroprotective peptides NAPVSIPQ (NAP) and SALLRSIPA (SAL) antagonize ethanol inhibition of L1 adhesion and prevent ethanol-induced growth retardation in mouse whole embryo culture. Here we ask whether NAP and SAL also prevent ethanol-induced major malformations of the nervous system. Gestational day 8.0 (3–5 somites) C57BL/6J mouse embryos were grown for 6 h in control medium, 100 mM ethanol and 10–10M peptides and then maintained for an additional 20 h in control medium. At the end of the culture period, only embryos having 18–19 somite pairs were examined and compared for the degree of neural tube closure. Ethanol exposure resulted in neural tube defects (NTDs) consistent with total dysraphia and anencephaly. Co-incubation with ethanol and L-NAP (all L-amino acids), D-NAP (all D-amino acids) or SAL significantly increased the percentage of embryos that had begun to close their neural folds at the level of the forebrain/midbrain junction or that had progressed beyond this stage of closure. P7A-NAP (NAPVSIAQ), which lacks neuroprotective activity, but retains activity as an antagonist of ethanol inhibition of L1 adhesion, was effective in preventing ethanol-induced NTDs. In contrast, I6A-NAP (NAPVSAPQ), which shows reduced efficacy as an ethanol antagonist but retains its neuroprotective efficacy, did not significantly diminish the induction of NTDs by ethanol. These findings demonstrate the ability of NAP and SAL to prevent ethanol-induced NTDs and support the hypothesis that ethanol teratogenesis is caused in part by ethanol inhibition of L1-mediated cell adhesion.
Investigations of Interactions of Chlormezanone Racemate and Its Enantiomers on Human Keratinocytes and Human Leucoytes in vitro
Authors: Wollina U. , Hipler U.-C. , Seeling A. , Oelschläger H.
Published: May 2005

Chlormezanone is a centrally acting muscle relaxant introduced in human therapy as a racemic substance. The following investigation was performed in order to investigate whether the racemate and both enantiomers differ in their potential cytotoxicty in vitro. We investigated antiproliferative effects and cytotoxicity (PicoGreen and ATP assay) for human HaCaT keratinocytes, production of oxygen radicals (ROS) by human interleukin-3-stimulated leukocytes (Lucigenin assay) and production of sulfoleukotrienes (Cellular Antigen Stimulation Test – CAST) by human leukocytes. In the dosage range of 0.001 to 0.1 mg/ ml chlormezanone, no antiproliferative effects were measured with the racemate and both enantiomers. At 1.0 mg/ml, a decrease of proliferative activity was seen after 48 h incubation time of about 50% for the enantiomers and of about 80% for the racemate (PicoGreen) and 50% (enantiomers) or 21% (racemate) in the ATP assay, respectively. ROS production was significantly inhibited at concentrations ≤0.01 mg/ ml by the racemate and the (+)-enantiomer, whereas the (–)-enantiomer was less effective. There was no stimulation of sulfidoleukotrienes in human leukocytes by chlormezanone. Present data argue for absence of significant cytotoxicity against human HaCaT keratinocytes and a dose-dependent suppression of ROS production by human leukocytes that is not uniform among the racemate and its enantiomers.
Weekly Paclitaxel in the Treatment of Advanced or Metastatic Breast Cancer Previously Treated or Not Treated with Docetaxel: A Phase II Study
Authors: Nishimura Reiki , Ogawa Takahiro , Kato Masato , Tanaka Maki , Hamada Yuzo , Shibata Takao , Ishikawa Emi , Koga Toshihiro , Mitsuyama Shoshu , Tamura Kazuo
Published: May 2005

Background: Paclitaxel has been approved for 3-weekly administration in Japan. Recent reports suggest that weekly paclitaxel can achieve a higher tumor response and lower toxicity. Methods: This study was designed to investigate the usefulness and tolerability of weekly paclitaxel by 1-hour infusion in patients with metastatic breast cancer who were previously treated with docetaxel or other anticancer agents. Results: Thirty-five patients were enrolled. The overall response rate was 41.2% (14/34, 95% confidence interval: 24.6–59.3%). The median time to progression and the median survival time were 218.5 and 624 days, respectively. One patient developed dyspnea, probably induced by a hypersensitivity reaction. The most common hematological toxicities were leukopenia and neutropenia, although no patients developed grade 4 leukopenia or neutropenia and G-CSF support was not required. Conclusions: Weekly paclitaxel could be safely administered and achieved a relatively high response rate. Weekly paclitaxel would be a good candidate second-line therapy for recurrent or advanced breast cancer.
Gestational Diabetes mellitus in Women in the Fourth Decade – Is Treatment Worthwhile?
Authors: Chan Ben Chong Pun , Lao Terence Tzu Hsi
Published: May 2005

Aim: To examine the influence of diet-treated gestational diabetes mellitus on the obstetric performance of mothers aged 40 and above. Method: We reviewed the delivery records of 205 mothers aged 40 and above who delivered over a 3-year period. A 75-gram oral glucose tolerance test was performed in all cases and 64 (31.2%) (18 primiparas and 46 multiparas) had gestational diabetes mellitus. This affected group of patients was compared with a group of age- and parity-matched controls to determine the impact of gestational diabetes mellitus on the obstetric outcome. Results: There was no difference in the maternal anthropometric parameters, antenatal complications, or labor performance. While no statistically significant difference was found in the infant anthropometric parameters, the study group had a lower incidence (p = 0.043) of large-for-gestational age infants. Conclusion: Our findings suggested the adverse effects of gestational diabetes mellitus on pregnancy outcome were confounded to a large extent by other factors such as age, parity, and obesity. Once compared with matched controls, gestational diabetes mellitus that can be successfully treated with diet therapy probably had minimal adverse effect on the obstetric outcome. Furthermore, diet treatment can probably reverse the effect of advanced maternal age on infant size in these women.
Histone H1 Modulates the Antioxidant Status in 9,10-Dimethylbenz[a]anthracene-Induced Experimental Breast Cancer
Authors: Vani G. , Shyamala Devi C.S.
Published: May 2005

Aim: Oxidative stress is implicated in the pathogenicity of cancer cells and contributes towards the response to antineoplastic agents. This study was aimed at assessing the antioxidant status in 9,10-dimethylbenz[a]anthracene-induced experimental animals treated with histone H1. Methods: Histone H1 was injected and the antioxidant status was assessed in erythrocytes and tumour tissue of experimental animals. The antioxidant status was monitored from the levels of lipid peroxides as thiobarbituric acid reactants and conjugated dienes in the haemolysate, serum, glutathione, and plasma vitamins A, E, C and ceruloplasmin. In the haemolysate, activities of antioxidant enzymes, including superoxide dismutase, catalase, glutathione reductase, γ-glutamyl transpeptidase, glutathione S-transferase, glutathione peroxidase and glucose-6-phosphate dehydrogenase, were assayed and erythrocyte fatty acid composition was analyzed by gas chromatography-mass spectrometry. All of the above parameters except fatty acid composition were assessed within the tumour tissue to assess the antioxidant status. Results: Treatment with histone H1 enhanced the antioxidant in erythrocyte at the end of the 2nd and 4th week by significantly decreasing thiobarbituric acid-reactive substances and conjugated dienes, by increasing glutathione levels, activities of antioxidant enzymes and favourably altering the erythrocyte fatty acid composition. Within the tumour tissue, a significant atrophy with significant alteration in antioxidant and antioxidant enzyme status was evident in treatment. Conclusion: These results validate the role of histone H1 as an antitumour agent in breast cancer.
Polymorphisms in prothrombotic genes and their impact on ischemic stroke in a Sardinian population
Authors: Di Angelantonio Emanuele , Nitsch Dorothea , Gigante Bruna , Zanda Bastianina , Stanzione Rosita , Evangelista Anna , Pirisi Angelo , Rosati Giulio , Volpe Massimo , Rubattu Speranza
Published: May 2005

Genetic factors are involved in the individual predisposition to develop ischemic stroke (IS). In the present study we tested the role of the Factor VII G10976A and –C122T polymorphisms on the susceptibility to develop IS in a genetically homogenous and clinically well ascertained case-control study including 294 cases (median age 75 years; 176 males/118 females) and 286 controls (median age 73 years; 163 males/123 females) in Sardinia, Italy. In addition, we carried out an exploratory analysis with respect to other frequently studied polymorphisms of haemostatic factor genes: Factor II G20210A, Factor V G1691A,, Fibrinogen α-chain Thr312Ala, Fibrinogen β-chain –C148T, Factor XIII G185T, GPIIb/IIIa T1565C. Among all the genes tested, FVII –C122T showed a significant, independent contribution to IS predisposition both in crude and adjusted analyses (crude OR 1.52, 95% CI 1.09–2.10, P=0.013; adjusted OR 1.48, 95% CI 1.04–2.09, P=0.028, respectively). Haplotype analyses revealed a conserved population structure with high linkage disequilibrium between both FVII mutations tested. Blood levels of FVII had an inverse relationship with the polymorphism involved. Apart from genetic influence, there was a significant role for hypertension (OR=1.7, 95% CI 1.19–2.43, P=0.003), hypercholesterolemia (OR=2.21, 95% CI 1.38–3.54, P=0.001) and atrial fibrillation (OR=1.66, 95% CI 1.06–2.58, P=0.026) on IS occurrence. In summary, we describe evidence for a possible direct association of FVII gene molecular variants with the occurrence of IS in a genetically homogenous human sample.
Eddy-Induced Heat Transport in the Subtropical North Pacific from Argo, TMI, and Altimetry Measurements
Authors: Qiu Bo , Chen Shuiming
Published: May 2005

Basin-scale heat transport induced by mesoscale oceanic eddies is estimated by combining satellite-derived sea surface height and temperature [temperature data are from the TRMM Microwave Imager (TMI)] data with Argo float temperature–salinity data. In the North Pacific Ocean subtropical gyre, warm (cold) temperature anomalies of mesoscale eddies are found to be consistently located to the west of high (low) SSH anomalies. The phase misalignment between the temperature and velocity anomalies, however, is largely confined to the seasonal thermocline, causing most of the eddy-induced heat transport to be carried in the surface 200-m layer. By establishing a statistical relationship between the surface and depth-integrated values of the eddy heat transport, the basin-scale eddy heat transport is derived from the concurrent satellite SSH/SST data of the past six years. In the Kuroshio Extension region, the meandering zonal jet is found to generate oppositely signed eddy heat fluxes. As a result, the zonally integrated poleward heat transport associated with the Kuroshio Extension is at a level O(0.1 PW), smaller than the previous estimates based on turbulent closure schemes. Large poleward eddy heat transport is also found in the subtropical North Pacific along a southwest–northeast-tilting band between Taiwan and the Midway Islands. This band corresponds to the region of the subtropical front, and it is argued that the relevant temperature field for identifying this band in the turbulent closure scheme models should be that averaged over the seasonal thermocline.
A Series of Zonal Jets Embedded in the Broad Zonal Flows in the Pacific Obtained in Eddy-Permitting Ocean General Circulation Models
Authors: Nakano Hideyuki , Hasumi Hiroyasu
Published: May 2005

A series of zonal currents in the Pacific Ocean is investigated using eddy-permitting ocean general circulation models. The zonal currents in the subsurface are classified into two parts: one is a series of broad zonal flows that has the meridional pattern slanting poleward with increasing depth and the other is finescale zonal jets with the meridional scale of 3°–5° formed in each broad zonal flow. The basic pattern for the broad zonal flows is similar between the coarse-resolution model and the eddy-permitting model and is thought to be the response to the wind forcing. A part of the zonal jets embedded in each zonal flow is explained by the anomalous local wind forcing. Most of them, however, seem to be mainly created by the rectification of turbulent processes on a β plane (the Rhines effect), and zonal jets in this study have common features with the zonally elongated flows obtained in previous modeling studies conducted in idealized basins. The position of zonal jets is not stable when the ocean floor is flat, whereas it oscillates only within a few degrees under realistic bottom topography.
The Role of Personal Experience in Contributing to Different Patterns of Response to Rare Terrorist Attacks
Authors: Yechiam Eldad , Barron Greg , Erev Ido
Published: May 2005

An examination of the behavioral effect of repeated terrorist attacks reveals that local residents (of the attacked area) appear to be much less sensitive to this risk than international tourists. Furthermore, the limited sensitivity on the part of local residents seems to diminish with time, even when the attacks continue. An experimental study shows a similar pattern in a laboratory experiment that focuses on a basic decision task: when making a single decision based on a description of the problem, people tend to be more risk averse. Personal experience with the problem reduces this sensitivity. These results highlight an interesting relationship between basic decision-making research and the study of the response to traumatic events.
Commercial Pacifism and Protracted Conflict
Authors: Friedman Gil
Published: May 2005

This study examines commercial pacifism and protracted conflict. It identifies constraints posed by protracted conflict on both the opportunity of the rivals to engage in mutually beneficial economic exchange and the impact of economic incentives on views on violence and peace. Based on this discussion, the study estimates regression models of Palestinians'views on diplomacy and attacks with 2001 public opinion data. The models suggest a modest role for economics. Views on Palestinian-Israeli economic integration and the economic impact of future peace exert important effects on views on diplomacy; income level and views on the economic consequences of Palestinian rebellion do not. Realist concerns appear to play the dominant role in views on attacks. Split-sample models reveal important interaction effects: the effects of economic incentives are substantively stronger and realist considerations sometimes weaker among people who deem economics the most important issue. All estimated models leave most of the variance unexplained.
Deliberation before the Revolution
Authors: Fung Archon
Published: May 2005

Deliberative democracy is a revolutionary political ideal that requires fundamental changes in political institutions, bases of collective decision making, and the distribution of resources. Perhaps because of its revolutionary character, accounts of deliberation in political theory thus far have offered little guidance for actors in actually-existing democratic circumstances. This article develops an ethical account of deliberative democratic action under imperfectly just conditions characterized by material and political inequality and failures of reciprocity. Under such conditions, appropriate principles of action can resolve the tension between deliberation and confrontational political activism. The logic of this account parallels the justification for civil disobedience: the extent of permissible deviation from deliberative norms increases according to the adversity of political circumstances. This ethical account is composed of principles of deliberative activism, applications of those principles to four kinds of increasing unfavorable circumstances, and a menu of institutional and political strategies that increase deliberative inclusion and equality.