bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of research on language teaching, learning and policy published in 2004 and 2005
Authors: Johnstone Richard
Published: November 2006

Most of the annual reviews which I have prepared for the present journal discuss roughly 100 articles published each previous year in top international research outlets. Even with such a high number per year, considerable selectivity has to be applied – the number of abstracts appearing up to the end of the October 2005 edition of Language Teaching, for example, amounts to 601, mostly published in 2005 and with still more to come for that year. The task of covering 2004 as well as 2005 within the one review, necessitated by personal circumstances, is therefore doubly daunting in its selectivity. For comprehensive coverage then, there is nothing in my view which can compete with the abstracts themselves as published in the present journal.
Three‐dimensional tropospheric water vapor in coupled climate models compared with observations from the AIRS satellite system
Authors: Pierce David W. , Barnett Tim P. , Fetzer Eric J. , Gleckler Peter J.
Published: November 2006

Changes in the distribution of water vapor in response to anthropogenic forcing will be a major factor determining the warming the Earth experiences over the next century, so it is important to validate climate models' distribution of water vapor. In this work the three‐dimensional distribution of specific humidity in state‐of‐the‐art climate models is compared to measurements from the AIRS satellite system. We find the majority of models have a pattern of drier than observed conditions (by 10–25%) in the tropics below 800 hPa, but 25–100% too moist conditions between 300 and 600 hPa, especially in the extra‐tropics. Analysis of the accuracy and sampling biases of the AIRS measurements suggests that these differences are due to systematic model errors, which might affect the model‐estimated range of climate warming anticipated over the next century.
Electron temperature of Titan's sunlit ionosphere
Authors: Galand M. , Yelle R. V. , Coates A. J. , Backes H. , Wahlund J.‐E.
Published: November 2006

Titan's upper atmosphere is ionized by solar radiation and particle bombardment from Saturn's magnetosphere. The induced ionosphere plays a key role in the coupling of Titan's atmosphere with the Kronian environment. It also provides unique signatures for identifying energy sources upon Titan's upper atmosphere. Here we focus on observations from the first, close flyby by the Cassini spacecraft and assess the ionization and electron heating sources in Titan's sunlit ionosphere. We compare CAPS electron spectra with spectra produced by an electron transport model based on the INMS neutral densities and a MHD interaction model. In addition, we compare RPWS electron temperature against the models. The important terms in the electron energy equation include loss through excitation of vibrational states of N2 and CH4, Coulomb collisions with suprathermal electrons, and thermal conduction. Our analysis highlights the important role of the magnetic field line configuration for aeronomic studies at Titan.
Passive image interferometry and seasonal variations of seismic velocities at Merapi Volcano, Indonesia
Authors: Sens‐Schönfelder C. , Wegler U.
Published: November 2006

We propose passive image interferometry as a technique for seismology that allows to continuously monitor small temporal changes of seismic velocities in the subsurface. The technique is independent of sources in the classical sense and requires just one or two permanent seismic stations. We retrieve the Green's functions that we use for interferometry from ambient seismic noise. Applying passive image interferometry to data from Merapi volcano we show that velocity variations can be measured with an accuracy of 0.1% with a temporal resolution of a single day. At Mt. Merapi the velocity variations show a strong seasonal influence and we present a depth dependent hydrological model that describes our observations solely based on precipitation.
Different response of clouds to solar input
Authors: Voiculescu Mirela , Usoskin Ilya G. , Mursula Kalevi
Published: November 2006

There is evidence that solar activity variations can affect the cloud cover at Earth. However, it is still unclear which solar driver plays the most important role in the cloud formation. Here we use partial correlations to distinguish between the effects of two solar drivers (cosmic rays and the UV irradiance) and the mutual relations between clouds at different altitudes. We find that the solar influence on cloud cover is not uniquely defined by one solar driver, but both seem to play a role depending on the climatic conditions and altitude. In particular, low clouds are mostly affected by UV irradiance over oceans and dry continental areas and by cosmic rays over some mid‐high latitude oceanic areas and moist lands with high aerosol concentration. High clouds respond more strongly to cosmic ray variations, especially over oceans and moist continental areas. These results provide observational constraints on related climate models.
Simultaneous identification of a plasmaspheric plume by a ground magnetometer pair and IMAGE Extreme Ultraviolet Imager
Authors: Abe S. , Kawano H. , Goldstein J. , Ohtani S. , Solovyev S. I. , Baishev D. G. , Yumoto K.
Published: November 2006

We have compared two quantities which were simultaneously observed by two different instruments at the same point of the plasmaspheric plume. One quantity is the field‐line eigenfrequency, which was obtained by applying the dual‐station H‐component power ratio method to geomagnetic data obtained from two ground magnetometers (at Tixie and Chokurdakh) of the Circum‐pan Pacific Magnetometer Network (CPMN). The other is the He+ column abundance obtained by the IMAGE satellite Extreme Ultraviolet Imager (IMAGE/EUV). We used the EUV He+ column abundance data mapped to the equatorial footpoint of the field‐line whose eigenfrequency we obtained from the ground data. The mapped EUV He+ column abundance is roughly proportional to the equatorial density of He+. The result of the IMAGE/EUV analysis showed an increase‐then‐decrease pattern of the He+ column abundance. On the other hand, as a result of analyzing the simultaneously observed ground magnetometer data, we found that the eigenfrequency showed a coherent decrease‐then‐increase pattern. Since this pattern takes place if the equatorial plasma density along the field line increased and then decreased, these two results are qualitatively consistent. In addition, the H‐power ratio showed an offset when either Tixie or Chokurdakh (these stations are longitudinally separated) stayed inside the plume. This feature can be explained if the overall ULF wave power was weaker in the plume than in the surrounding trough. With the above findings, this paper is the first to identify a plume from both the spacecraft image and the ground magnetometer ULF waves.
Relativistic diffusion coefficients for superluminous (auroral kilometric radiation) wave modes in space plasmas
Authors: Xiao Fuliang , He Huiyong , Zhou Qinghua , Zheng Huinan , Wang Shui
Published: November 2006

We have constructed expressions of the relativistic diffusion coefficients in both pitch angle and momentum resulting from gyroresonant interactions between electrons and superluminous (R–X, L–O, L–X) wave modes that are generated as auroral kilometric radiation (AKR) in the Earth's magnetosphere. Detailed analysis is made of wave resonant frequencies for each given harmonic n, electron energy, wave normal angles for two typical regions of the magnetosphere: the higher‐density region η = ∣Ωe∣2/ω2pe < 1 (e.g., near the geostationary orbit) and the lower‐density region η > 1 (e.g., at the high latitude of the radiation belts), where ∣Ωe∣ and ωpe are the electron gyrofrequency and the plasma frequency. The resonant frequency range in the higher‐density region is found to be generally smaller than that in the lower‐density region, and the efficient electron gyroresonance with the superluminous wave modes occurs mainly at the higher harmonics, e.g., ∣n∣ ≥ 3. In contrast to the subluminous waves, e.g., chorus which has easily up to three resonant frequencies, only one or two resonant frequencies were found for superluminous waves at each combination of wave and particle parameters of interest. Numerical calculations for diffusion coefficients of the momentum Dpp, the pitch angle Dαα, and the mixed Dpα are performed specifically for the two typical regions above. It is found that the momentum diffusion generally dominates over the pitch angle diffusion, namely, Dpp > ∣Dpα∣ > Dαα for the pitch angle α above a critical angle αc, whereas Dαα generally dominates below the critical angle αc. Specifically, Dpp/Dαα can exceed 10 for α > αc ≈ 7.5° and η = 0.2, while for α > αc ≈ 30° and η = 20. This is a new result in contrast to the case of subluminous waves (e.g., whistler mode waves) in which basically Dαα > ∣Dpα∣> Dpp. We have also presented some estimates regarding what wave amplitudes are required to produce particular acceleration timescales and found that the required wave amplitudes in the lower‐density region are much lower than those in the higher‐density region. The results suggest that superluminous wave modes may contribute significantly to both the stochastic acceleration of trapped electrons (with larger pitch angle) and the loss process of untrapped electrons (with smaller pitch angles) during magnetic storms if those waves are found to be present in the radiation belts of the Earth, but this needs to be further investigated.
Influence of exciton-phonon coupling on the energy position of the near-band-edge photoluminescence of ZnO nanowires
Authors: Voss T. , Bekeny C. , Wischmeier L. , Gafsi H. , Börner S. , Schade W. , Mofor A. C. , Bakin A. , Waag A.
Published: November 2006

Room-temperature near-band-edge photoluminescence of ZnO is composed of contributions from free-exciton recombination and its longitudinal-optical phonon replica. By tracking the photoluminescence of ZnO nanowires from 4K up to room temperature, the authors show that the relative contributions of these emission lines show a strong variation for samples grown under different conditions. The varying coupling strengths of the excitons and phonons thus lead to a significant shift of the energy position of the room-temperature photoluminescence. They verify that this is not caused by laser heating or stress/strain but is most probably related to crystalline imperfections in the surface region.
Determination of the elastic modulus of native collagen fibrils via radial indentation
Authors: Heim August J. , Matthews William G. , Koob Thomas J.
Published: November 2006

The authors studied the elastic response of single, native collagen fibrils extracted from tissues of the inner dermis of the sea cucumber, Cucumaria frondosa, via local nanoscale indentation with an atomic force microscope (AFM). AFM imaging of fibrils under ambient conditions are presented, demonstrating a peak-to-peak periodicity, the d band, of dehydrated, unfixed fibrils to be ∼64.5nm. Radial indentation experiments were performed, and the measured value for the reduced modulus is 1–2GPa.
Lasing in GaAs∕AlGaAs self-assembled quantum dots
Authors: Mano T. , Kuroda T. , Yamagiwa M. , Kido G. , Sakoda K. , Koguchi N.
Published: November 2006

The authors have demonstrated photopumped laser action of self-assembled ring-shaped GaAs quantum dots (QDs) grown by droplet epitaxy. Morphological control of the QD shape from conelike dots to ringlike ones results in a narrow spectral band of photoluminescence from the QD ensemble, reflecting their small size distribution. Using ring-shaped QDs as an active laser medium, they observed multimodal stimulated emissions from the ground state at temperatures of up to 300K.
Hyperfine splitting from magnetic boride domains embedded in Fe–Co–Ni–Al–B–Si alloy
Authors: Kuo Hsin-Fu , Chin Wei , Cheng Tung-Wen , Hsu Wen-Kuang , Yeh Jien-Wei
Published: November 2006

Fe–Co–Ni–Al–B–Si alloy shows permeability at the gigahertz range and it is proposed that the underlying mechanism involves hyperfine splitting arising, from embedded boride domains.
Spin-polarized conduction in oxide magnetic tunnel junctions with magnetic and nonmagnetic insulating barrier layers
Authors: Alldredge L. M. B. , Chopdekar R. V. , Nelson-Cheeseman B. B. , Suzuki Y.
Published: November 2006

Epitaxial magnetic tunnel junctions with electrodes of spinel-structure Fe3O4 and perovskite La0.7Sr0.3MnO3 have been fabricated and characterized. Spinel barrier layers of magnetic FeGa2O4 and nominally nonmagnetic Mg2TiO4 were used to provide a good interface with the more sensitive Fe3O4 electrode interface. Junction magnetoresistances (JMRs) of up to −11% at 60K and −26% at 70K were observed for FeGa2O4 and Mg2TiO4 barrier junctions, respectively. The JMR bias dependence and junction resistance versus temperature data indicate that a majority of the junctions are dominated by elastic tunneling below about 50mV and by inelastic hopping through the barrier at higher bias.
Tunable pinning in superconducting films with magnetic microloops
Authors: Silhanek A. V. , Gillijns W. , Moshchalkov V. V. , Metlushko V. , Ilic B.
Published: November 2006

The authors study the flux pinning properties of superconductor/magnetic microring lattice hybrid structures. The used open triangular micromagnets represent an eightfold degree of freedom system, with six polarized and two flux-closure possible states. By conveniently choosing the magnetic state of the underlying rings, it is possible to induce different pinning potentials. They show that the magnetic vortex state with minimum stray field produces a weaker pinning in comparison with the polarized states.
Doping of ZnO by group-IB elements
Authors: Yan Yanfa , Al-Jassim M. M. , Wei Su-Huai
Published: November 2006

The authors present their first-principles calculations of doping effects in ZnO with group-IB elements such as Cu, Ag, and Au. The calculated transition energies ε(0∕−) for substitutional Cu, Ag, and Au are 0.7, 0.4, and 0.5eV, respectively. The calculated formation energies are very low for these group-IB elements on the substitutional sites, but rather high at the interstitial sites under oxygen-rich growth conditions. Under the conditions, the formation of major hole-killer defects, such as oxygen vacancies and Zn interstitial, are suppressed. Thus, Ag may be a good candidate for producing p-type ZnO.
All-organic hot-carrier triodes with thin-film metal base
Authors: Ou Tzu-Min , Cheng Shiau-Shin , Huang Chun-Yuan , Wu Meng-Chyi , Chan I-Min , Lin Shih-Yen , Chan Yi-Jen
Published: November 2006

In this letter, the authors investigate the promising vertical-type triodes based on small organic molecules and the related hot-carrier transport. The devices show transistorlike characteristics, in which output current can be modulated by demanding different input currents on their thin metal base electrodes. By using pentacene for the channel layer material and N,N′-di(naphthalen-l-yl)-N,N′-diphenyl-benzidine for the carrier energy-enhancing layer, the vertical-type hot carrier triodes exhibit a good current saturation with current gain of 2.38 for both the common-base and common-emitter configurations. The mechanism of operation is proposed and examined by the basic electrical measurements.
Control of p- and n-type carriers by end-group substitution in oligo-p-phenylenevinylene-based organic field-effect transistors
Authors: Yasuda Takeshi , Saito Masatoshi , Nakamura Hiroaki , Tsutsui Tetsuo
Published: November 2006

Organic field-effect transistors (OFETs) consisting of vacuum-evaporated oligo-p-phenylenevinylene derivatives were prepared, and the device characteristics were evaluated. The fabricated OFETs showed typical p-type characteristics for methyl-substituted oligo-p-phenylenevinylene (OPV). A field-effect hole mobility of 0.13cm2V−1s−1 emerged with a threshold voltage of −33V and an on/off ratio of 5.8×105. On the other hand, OFETs showed typical n-type characteristics for trifluoromethyl-substituted OPV. A field-effect electron mobility of 0.013cm2V−1s−1 emerged with a threshold voltage of 45V and an on/off ratio of 4.2×104. The authors have observed clear changes from p-channel to n-channel conductions in OFETs by chemically modifying oligo-p-phenylenevinylenes.
Are Users of Complementary and Alternative Medicine Sicker than Non‐Users?
Authors: Shmueli Amir , Shuval Judith
Published: November 2006

Higher utilization of complementary and alternative medicine (CAM), both in cross‐sections and over time, is commonly related to better socioeconomic status and to increased dissatisfaction with conventional medicine and its values. Little is known about health differences between users and non‐users of CAM. The objective of the paper is to explore the difference in health measured by the SF‐36 instrument between users and non‐users of CAM, and to estimate the relative importance of the SF‐36 health domains scales to the likelihood of consulting CAM providers. Interviews were used to collect information from a sample of 2000 persons in 1993 and 2500 persons in 2000, representing the Israeli Jewish urban population aged 45–75 in those years. Bivariate and logistic regression analyses were used to explore the above associations. The results show that while users of CAM enjoy higher socioeconomic status and younger age, they tend to report worse health than non‐users on the eight SF‐36 health domains scales in both years. However, controlling for personal characteristics, lower scores on the bodily pain, role‐emotional and vitality scales are related to greater likelihood of CAM use in 2000. In 1993, no scale had a significant adjusted association with the use of CAM. The conclusions are that CAM users tend to report worse health. With CAM becoming a mainstream, though somewhat luxurious, medical practice, pain and affective‐emotional distress are the main drivers of CAM use.
Effects of the Short Chain Sugar Acid 2‐Buten‐4‐Olide on the Hypothalamo‐Pituitary‐Adrenal Axis in Normal and Adjuvant‐Induced Arthritic Rats
Authors: Kawasaki M. , Onaka T. , Saito J. , Hashimoto H. , Suzuki H. , Otsubo H. , Fujihara H. , Okimoto N. , Ohnishi H. , Nakamura T. , Ueta Y.
Published: November 2006

The effects of intraperitoneal (i.p.) administration of 2‐buten‐4‐olide (2‐B4O), an endogenous sugar acid, on the hypothalamo‐adenohypophysial system were examined in Lewis rats that were normal and in adjuvant‐induced arthritic (AA) rats. In comparison with vehicle‐treated rats, the plasma corticosterone and c‐fosmRNA levels in the paraventricular nucleus (PVN) of normal rats increased significantly after i.p. administration of 2‐B4O. Dual immunostaining revealed that almost all corticotrophin‐releasing factor (CRF)‐immunopositive neurones in the parvocellular division of the PVN exhibited Fos‐like immunoreactivity (LI) 120 min after i.p. administration of 2‐B4O (100 mg/kg). In the AA rats, repeated i.p. administration of 2‐B4O (100 mg/kg) after immunisation significantly suppressed the expression of clinical symptoms and significantly increased plasma concentrations of corticosterone. Further, repeated i.p. administration of 2‐B4O significantly increased CRF mRNA levels in the PVN and pro‐opiomelanocortin mRNA levels in the anterior pituitary; however, they did not change arginine vasopressin mRNA levels in the parvocellular division of the PVN. These results suggest that i.p. administration of 2‐B4O activates the hypothalamo‐pituitary‐adrenal (HPA) axis via the activation of CRF neurones in the PVN, and the activation of the HPA axis by i.p. administration of 2‐B4O may be associated with the inhibition of AA in rats.
Malignant hyperthermia and central core disease causative mutations in Swedish patients
Authors: Broman M. , Islander G. , Müller C. R. , Ranklev‐Twetman E.
Published: November 2006

Background:  Malignant hyperthermia (MH) susceptibility is a pharmacogenetic disorder of intracellular calcium homeostasis. In susceptible individuals, halogenated anaesthetics and/or suxamethonium may trigger an MH reaction. The diagnosis of MH susceptibility is made by an in vitro contracture test of biopsied muscle strips.

Methods:  In 27 MH susceptible (MHS) probands and four MH negative (MHN) probands, exons 17, 39, 40, 45 and 46 of the RYR1 gene were screened for MH causative mutations. In addition, in three patients with established central core disease (CCD), exons 17, 39, 40, 45 and 46 and exons 95, 100, 101 and 102 were screened for MH and CCD causative mutations. All screenings were performed by direct sequencing of the entire exons.

Results:  MH causative mutations were found in five of the 27 MHS probands (19%). CCD causative mutations were found in two of three CCD patients in the C‐terminal exons. None of the CCD patients showed a mutation in N‐terminal exon 17 or in the central exons.

Conclusions:  In a Swedish population, screening of N‐terminal exon 17 and the central exons for MH causative mutations in the RYR1 gene covers 19% of families. Thus, other mutations must also be responsible for MH susceptibility in Sweden. Although the number of CCD patients in this study was small, screening of the C‐terminal exons for CCD causative mutations seems to be a promising tool in the process of making a diagnosis.
Root nitrogen concentration of sorghum above 2% produces least Striga hermonthica seed stimulation
Authors: Ayongwa G.C. , Stomph T.J. , Emechebe A.M. , Kuyper T.W.
Published: November 2006

A series of pot and laboratory experiments was carried out to assess the effects of N status of sorghum roots and timing of N application (as NH4NO3) on the germination of Striga hermonthica seeds. Root N concentrations varied from 10 to 26 mg N g−1. The cut root and the root exudates technique used in assaying S. hermonthica seed germination gave similar results. However, the cut root technique was easier to handle and more discriminating at low germination levels. S. hermonthica seed germination per unit sorghum root mass followed a broken‐stick model. It decreased with increasing root N concentrations, reaching lowest levels at a root N concentration of 19.5 mg N g−1, after which no further reduction occurred. It was not possible to reduce S. hermonthica seed germination to a zero level. Timing of N application influenced the time a higher N concentration is reached, not the S. hermonthica seed germination. Both timing and rate of N application are important in maintaining root N concentrations above 19.5 mg N g−1, thereby potentially reducing S. hermonthica germination in the field. Translation of results to reductions in infection levels and yield losses is hampered by density‐dependent relations after the S. hermonthica germination stage.
Stereoselective debromination and selective reduction of vic-dibromides with nickel boride
Authors: Khurana Jitender M , Kandpal Bhaskar M , Kukreja Gagan , Sharma Purnima
Published: November 2006

A simple procedure is reported for the stereoselective debromination of vic-dibromides with nickel boride at ambient temperature. Debromination with concomitant reduction of vic-dibromides to give dihydro products in a one-pot reaction is also reported. α,β-Dibromoketones can also be converted to their corresponding alcohols.Key words: debromination, vic-dibromides, stereoselective, reduction, E-alkenes.
Theoretical study on six-fold coordinated silicon in silicophosphate compounds
Authors: Rabaâ Hassan , Bkiri Fatima
Published: November 2006

Extended Hückel tight-binding (EHTB) calculations were performed on silicophosphate compounds with six-coordinated silicon. Speculative structures related to silicon coordination in SiP2O7 are reported. To account for the particular structural distortion caused by the presence of SiO6 in the silicon pyrophosphate, it is important to examine how the stability and the band gap of the extended structure of SiP2O7 are affected. Different theoretical tools are used (EHTB, ab initio Hartree–Fock, and density functional theory DFT-B3LYP). To obtain detailed descriptions of the incorporation of hexacoordinated silicon in this material, the band structures in SiP2O7 and [P2O7]4– were analyzed. It seems that the diffuse orbitals of silicon and the high energy of the Si 3p orbital lead to higher energy coordination and contribute to the breaking of the P-O-P bridge and the forming of a Si-O-P entity in this material. In addition, to provide more evidence of the existence of the octahedral silicon coordination in SiP2O7 (1), two model clusters [P4Si2O23H18] (2) and [P4Si2O19H10] (3) involving silicon atoms in octahedral and tetrahedral sites were investigated using Hartree–Fock and DFT theories. A remarkable agreement between calculated and experimental bond lengths for Si—O and P—O is obtained using the DFT calculation. The model cluster 2 corroborates the structural change in the Si-O-P and P-O-P fragments seen in 1. The IR vibrational frequencies are calculated for both model clusters and are predicted to shift towards lower frequencies in the octahedral Si sites, which is consistent with experimental data.Key words: silicophosphate, SiO6, band structure, tight-binding calculations, Hartree-Fock, DFT, B3LYP, model cluster, IR frequencies.
Buffer capacity in multiple chemical reaction systems involving solid phases
Authors: Fishtik Ilie , Povar Igor
Published: November 2006

The buffer capacity of a chemical species in a multiple chemical reaction system is discussed in terms of a special class of stoichiometrically unique reactions referred to as response reactions (RERs). More specifically, it is shown that the buffer capacity may be partitioned into a sum of contributions associated with RERs. This finding provides a deeper understanding of the factors that determine the buffer capacity. In particular, the main contributions to the buffer capacity come from the RERs involving the most abundant species. Concomitantly, the RERs approach provides a simple stoichiometric algorithm for the derivation and analysis of the buffer capacity that may be easily implemented into a computer software.Key words: buffer capacity, response reaction, heterogeneous system, stoichiometric coefficient.
Regio- and stereo-selectively kinetic resolution of four stereoisomers of 1-phenylbutan-1,3-diol by Candida rugosa lipase
Authors: Chen Yi-Hui , Joly S , Huang Pin-Mei , Sung Kuangsen
Published: November 2006

Regio- and stereo-selective Candida rugosa lipase (CRL)-catalyzed acetylations of (±)-syn-1-phenylbutan-1,3-diols ((±)-syn-1) generated two monoacetates, (+)-syn-2 and (–)-syn-3, whereas that of (±)-anti-1 produced a monoacetate, (+)-anti-3, and an unreacted (–)-anti-1.Key words: Candida rugosa lipase, kinetic resolution, 1,3-diols.
Experimental and theoretical study of the electrochemical behavior of N-protonated dopamine at Nafion multiwalled carbon nanotubes (MWNTs) modified glassy carbon (GCE) electrode
Authors: Song Yuanzhi , Song Yang
Published: November 2006

The electrochemistry of N-protonated dopamine (DAH+) was studied by cyclic voltammetry (CV) at a glassy carbon electrode modified by Nafion multiwalled carbon nanotubes (MWNTs) in phosphate buffers (pH 5.50) and the results show that the standard electrode potential of half reaction for DAH+(O),H+/ DAH+(R) is 0.74 V. Calculations are performed using DFT B3LY/6-31G(d,p) for nine conformers of N-protonated dopamine (DAH+(R)) and three conformers of oxidized N-protonated dopamine (DAH+(O)). The energies of solvation and sum of electronic and thermal free energies of DAH+(R), DAH+(O), p-benzoquinone (p-BQ), and p-hydroquinone (p-HQ) are calculated at same level. The theoretical weighted average of the standard electrode potential (0.732 V) for DAH+(O),H+/ DAH+(R), using the transformed Gibbs free energies of the stable DAH+(R) and DAH+(O) with a p-BQ, H+/p-HQ reference electrode, is consistent with the experimental one of 0.74 V.Key words: dopamine, DFT, cyclic voltammetry, standard electrode potential.
A MULTISCALE CELLULAR AUTOMATA MODEL FOR SIMULATING COMPLEX TRANSPORTATION SYSTEMS
Authors: TOPA PAWEŁ , DZWINEL WITOLD , YUEN DAVID A.
Published: November 2006

We present a new two-level numerical model describing the evolution of transportation network. Two separate but mutually interacting sub-systems are investigated: a starving environment and the network. We assume that the slow modes of the environment growth can be modeled with classical cellular automata (CA) approach. The fast modes representing the transportation network, we approximate by the graph of cellular automata (GCA). This allows the simulation of transportation systems over larger spatio-temporal scales and scrutinizing global interactions between the network and the environment. We show that the model can mimic the realistic evolution of complex river systems. We also demonstrate how the model can simulate a reverse situation. We conclude that the paradigm of this model can be extended further to a general framework, approximating many realistic multiscale transportation systems in diverse fields such as geology, biology and medicine.
ROBUSTNESS OF COMPLETE STABILITY FOR 1-D CIRCULAR CNNs
Authors: DI MARCO MAURO , GHILARDI CHIARA
Published: November 2006

This paper investigates the issue of robustness of complete stability of standard Cellular Neural Networks (CNNs) with respect to small perturbations of the nominally symmetric interconnections. More specifically, a class of circular one-dimensional (1-D) CNNs with nearest-neighbor interconnections only, is considered. The class has sparse interconnections and is subject to perturbations which preserve the interconnecting structure. Conditions assuring that the perturbed CNN has a unique equilibrium point at the origin, which is unstable, are provided in terms of relative magnitude of the perturbations with respect to the nominal interconnection weights. These conditions allow one to characterize regions in the perturbation parameter space where there is loss of stability for the perturbed CNN. In turn, this shows that even for sparse interconnections and structure preserving perturbations, robustness of complete stability is not guaranteed in the general case.
HARMONIC BALANCE ANALYSIS OF THE GENERALIZED CHUA'S CIRCUIT
Authors: SAVACI F. ACAR , GÜNEL SERKAN
Published: November 2006

In this paper, the harmonic balance analysis of Generalized Chua's circuit exhibiting n-scroll attractors has been accomplished. The dual-input describing functions of the piecewise-linear characteristics of Chua's diode have been obtained and based on the harmonic balance principle, the existence and the locations of the n-scrolls have been verified.
MANIPULATING PLANAR SHAPES WITH A LIGHT-SENSITIVE EXCITABLE MEDIUM: COMPUTATIONAL STUDIES OF CLOSED-LOOP SYSTEMS
Authors: SKACHEK SERGEY , ADAMATZKY ANDREW , MELHUISH CHRIS
Published: November 2006

We study how to employ space-time dynamics in nonlinear media to achieve distributed manipulation of objects — positioning, orienting and transporting objects by wave-fronts and patterns in excitable medium. We present the results of computational experiments of a massive parallel actuator controlled by a cellular-automaton model of an excitable medium. The model incorporates closed-loop actuation where sites of the medium can be excited not only by their closest neighbors but also by the edges of the manipulated object. We analyze motion of basic planar shapes (either initially aligned along axes or randomly oriented) induced by an actuator controlled by excitable lattice with various excitation rules. We demonstrate that space-time excitation dynamics in discrete nonlinear media bears a huge potential in terms of sensible nontrivial manipulation of planar shapes.
NOISE-SENSITIVITY IN MACHINE TOOL VIBRATIONS
Authors: BUCKWAR E. , KUSKE R. , L'ESPERANCE B. , SOO T.
Published: November 2006

We consider the effect of random variation in the material parameters in a model for machine tool vibrations, specifically regenerative chatter. We show that fluctuations in these parameters appear as both multiplicative and additive noise in the model. We focus on the effect of additive noise in amplifying small vibrations which appear in subcritical regimes. Coherence resonance is demonstrated through computations, and is proposed as a route for transitions to larger vibrations. The dynamics also exhibit scaling laws observed in the analysis of general stochastic delay differential models.
Glucocorticoids produce whole body insulin resistance with changes in cardiac metabolism
Authors: Qi Dake , Rodrigues Brian
Published: November 2006

Insulin resistance is viewed as an insufficiency in insulin action, with glucocorticoids being recognized to play a key role in its pathogenesis. With insulin resistance, metabolism in multiple organ systems such as skeletal muscle, liver, and adipose tissue is altered. These metabolic alterations are widely believed to be important factors in the morbidity and mortality of cardiovascular disease. More importantly, clinical and experimental studies have established that metabolic abnormalities in the heart per se also play a crucial role in the development of heart failure. Following glucocorticoids, glucose utilization is compromised in the heart. This attenuated glucose metabolism is associated with altered fatty acid supply, composition, and utilization. In the heart, elevated fatty acid use has been implicated in a number of metabolic, morphological, and mechanical changes and, more recently, in “lipotoxicity”. In the present article, we review the action of glucocorticoids, their role in insulin resistance, and their influence in modulating peripheral and cardiac metabolism and heart disease.
AQP7 is localized in capillaries of adipose tissue, cardiac and striated muscle: implications in glycerol metabolism
Authors: Skowronski Mariusz T. , Lebeck Janne , Rojek Aleksandra , Praetorius Jeppe , Füchtbauer Ernst-Martin , Frøkiær Jørgen , Nielsen Søren
Published: November 2006

Aquaporin (AQP7) is expressed in proximal tubules and is involved in glycerol uptake. The cellular expression and physiological function in other organs remain largely undefined. AQP7 knockout (KO) mice were generated and used for immunohistochemical analyses to define the organ and cellular expression of AQP7. AQP7 labeling was found in kidney proximal tubule, heart, skeletal muscle, testis, epididymis, as well as in white and brown adipose tissue (WAT and BAT) of wild-type mice. Importantly, immunoreactivity was completely absent from these tissues in AQP7 KO mice. At the cellular level, the capillary endothelium WAT and BAT displayed prominent staining, whereas AQP7 labeling in adipocyte membranes was undetectable. Double-labeling confocal microscopy revealed coexpression of AQP7 with capillary AQP1 but not with adipocyte GLUT4. Moreover, immunoelectron microscopy and RT-PCR of isolated microvessels confirmed the vascular AQP7 expression. Distinct immunolabeling of the capillary endothelium was also observed in both skeletal and heart muscle with no apparent staining of skeletal or cardiac myocytes. As previously reported, specific immunolabeling was confined to brush border in segment 3 renal proximal tubules and to spermatids and spermatozoa in male reproductive tract. The expression of AQP7 was induced up to 2.2-fold in WAT of mice with streptozotocin-induced diabetes mellitus (S-DM) compared with controls and fasting for 72 h (but not 24 h) induced significant increase in AQP7 expression. In conclusion, AQP7 is expressed in capillary endothelia of adipose tissue (and cardiac and striated muscle) and is upregulated in WAT in response to S-DM supporting its role in glycerol metabolism.
Angiotensin II increases chloride absorption in the cortical collecting duct in mice through a pendrin-dependent mechanism
Authors: Pech Vladimír , Kim Young Hee , Weinstein Alan M. , Everett Lorraine A. , Pham Truyen D. , Wall Susan M.
Published: November 2006

Pendrin ( Slc26a4) localizes to type B and non-A, non-B intercalated cells in the distal convoluted tubule, the connecting tubule, and the cortical collecting duct (CCD), where it mediates apical Cl−/HCO3−exchange. The purpose of this study was to determine whether angiotensin II increases transepithelial net chloride transport, JCl, in mouse CCD through a pendrin-dependent mechanism. JCland transepithelial voltage, VT, were measured in CCDs perfused in vitro from wild-type and Slc26a4 null mice ingesting a NaCl-replete diet or a NaCl-replete diet and furosemide. In CCDs from wild-type mice ingesting a NaCl-replete diet, VTand JClwere not different from zero either in the presence or absence of angiotensin II (10−8M) in the bath. Thus further experiments employed mice given the high-NaCl diet and furosemide to upregulate renal pendrin expression. CCDs from furosemide-treated wild-type mice had a lumen-negative VTand absorbed Cl−. With angiotensin II in the bath, Cl−absorption doubled although VTdid not become more lumen negative. In contrast, in CCDs from furosemide-treated Slc26a4 null mice, Cl−secretion and a VTof ∼0 were observed, neither of which changed with angiotensin II application. Inhibiting ENaC with benzamil abolished VTalthough JClfell only ∼50%. Thus substantial Cl−absorption is observed in the absence of an electromotive force. Attenuating apical anion exchange with the peritubular application of the H+-ATPase inhibitor bafilomycin abolished benzamil-insensitive Cl−absorption. In conclusion, angiotensin II increases transcellular Cl−absorption in the CCD through a pendrin- and H+-ATPase-dependent process.
Profiling at mRNA, protein, and metabolite levels reveals alterations in renal amino acid handling and glutathione metabolism in kidney tissue ofPept2−/−mice
Authors: Frey Isabelle M. , Rubio-Aliaga Isabel , Siewert Anne , Sailer Daniela , Drobyshev Aleksey , Beckers Johannes , de Angelis Martin Hrabé , Aubert Julie , Hen Avner Bar , Fiehn Oliver , Eichinger Hans M. , Daniel Hannelore
Published: November 2006

PEPT2 is an integral membrane protein in the apical membrane of renal epithelial cells that operates as a rheogenic transporter for di- and tripeptides and structurally related drugs. Its prime role is thought to be the reabsorption of filtered di- and tripeptides contributing to amino acid homeostasis. To elucidate the role of PEPT2 in renal amino acid metabolism we submitted kidney tissues of wild-type and a Pept2−/−mouse line to a comprehensive transcriptome, proteome and metabolome profiling and analyzed urinary amino acids and dipeptides. cDNA microarray analysis identified 147 differentially expressed transcripts in transporter-deficient animals, and proteome analysis by 2D-PAGE and MALDI-TOF-MS identified 37 differentially expressed proteins. Metabolite profiling by GC-MS revealed predominantly altered concentrations of amino acids and derivatives. Urinary excretion of amino acids demonstrated increased glycine and cysteine/cystine concentrations and dipeptides in urine were assessed by amino acid analysis of urine samples before and after in vitro dipeptidase digestion. Dipeptides constituted a noticeable fraction of urinary amino acids in Pept2−/−animals, only, and dipeptide-bound glycine and cystine were selectively increased in Pept2−/−urine samples. These findings were confirmed by a drastically increased excretion of cysteinyl-glycine (cys-gly). Urinary loss of cys-gly together with lower concentrations of cysteine, glycine, and oxoproline in kidney tissue and altered expression of mRNA and proteins involved in glutathione (GSH) metabolism suggests that PEPT2 is predominantly a system for reabsorption of cys-gly originating from GSH break-down, thus contributing to resynthesis of GSH.
Public Opinion, the War in Iraq, and Presidential Accountability
Authors: Voeten Erik , Brewer Paul R.
Published: November 2006

How do citizens hold their leader accountable during an ongoing war? The authors distinguish between two models of accountability—the “decision maker” and “managerial” models—and investigate their implications in the context of the current war in Iraq. They employ a novel measurement model and a database of survey marginals to estimate weekly time series of aggregate beliefs about various aspects of the war. Consistent with the “decision maker” model, they find that shifts in aggregate support for the war have a greater impact on presidential approval than do equivalent shifts in perceptions of war success or approval of the president’s handling of the war. Conversely, aggregate perceptions of success are more responsive to casualties and key events than are aggregate beliefs about the war’s merits. This suggests that the link from casualties and events to presidential approval is less direct than previously assumed.
Martyrdom Contracts
Authors: Ferrero Mario
Published: November 2006

This article emphasizes the similarities between such diverse instances of public-spirited suicide as the Islamic martyrs of yesterday and today, the anarchists, the Japanese kamikaze of World War II, the Tamil Tigers of Sri Lanka, and the Christian martyrs under the Roman Empire. It tries to accommodate this disparate evidence within a single two-period, expected utility model of a martyrdom contract, to which volunteers sign up in the expectation of probabilistic earthly rewards. Contract enforcement is ensured by a sufficiently strong stigma, or social sanction, placed on renegades. The main implication for counterterrorism policy is that the sanction should be softened, so as to turn prospective martyrs into apostates.
The Evolution of Ethnocentrism
Authors: Hammond Ross A. , Axelrod Robert
Published: November 2006

Ethnocentrism is a nearly universal syndrome of attitudes and behaviors, typically including in-group favoritism. Empirical evidence suggests that a predisposition to favor in-groups can be easily triggered by even arbitrary group distinctions and that preferential cooperation within groups occurs even when it is individually costly. The authors study the emergence and robustness of ethnocentric behaviors of in-group favoritism, using an agent-based evolutionary model. They show that such behaviors can become widespread under a broad range of conditions and can support very high levels of cooperation, even in one-move prisoner’s dilemma games. When cooperation is especially costly to individuals, the authors show how ethnocentrism itself can be necessary to sustain cooperation.
Early Entries Into Adult Roles
Authors: Roche Kathleen M. , Ensminger Margaret E. , Ialongo Nicholas , Poduska Jeanne M. , Kellam Sheppard G.
Published: November 2006

This study examines how early entries into adult roles are associated with aggressive and violent behavior occurring from early adolescence to young adulthood among 499 males and 578 females living in low-income, central-city neighborhoods. Among males, engagement in adult roles accounted for the relationship between higher levels of aggressive behavior during early adolescence and violence in young adulthood. Males who lived independently and males who were behind in school or not in school at age 19 and 20 years (regardless of labor force participation) were at increased risk of engaging in violence in young adulthood. Among females, the positive association between early adolescent aggressive behavior and violence in young adulthood persisted even after accounting for involvement in adult roles. For females, parenthood and independent living were associated with involvement in violence during young adulthood in varying ways depending on labor force participation.
Identity confusions
Authors: Garcia J. L. A.
Published: November 2006

This article responds to logical and social theses proposed by Professor José Medina in discussing the relativity of identity. In exploring the metaphor of family resemblance, the author argues that its causal mechanism is biological, not social; particular features of being a woman, or of belonging to a racial or ethnic group, cannot be reduced to social constructions. The article skeptically discusses the supposed importance of sex, race, and ethnicity to a person’s individual identity, and suggests that moral significance finds its origin and grounding elsewhere. It concludes that no liberation can be ‘complete, or even adequate’ until it liberates the mind from ‘“scripts” rooted in the delusion of “collective identities”’.
Constitution Making and Decolonization
Authors: Rothermund Dietmar
Published: November 2006

In addition to its two world wars, the rapid decolonization after 1947 has been the most important phenomenon of the 20th century. The two wars led to the decline of the European colonial empires and speeded up decolonization. This process has spawned more than one hundred new nations which in many cases did not exist in this way before. It also fixed territorial boundaries, most of which have remained unaltered ever since. In the course of decolonization constitutions have been made which have also survived unless they have been suspended by military coups. Many of these constitutions bear the stamp of the process of decolonization because they were framed with a view to facilitating the transfer of power. Usually the grant of independence was preceded by various steps in the devolution of power which left their traces in the constitutional documents. Since this devolution implied the prescription of administrative procedures, these constitutional documents often contain a great deal of contingent detail, whereas ‘normal’ constitutions are restricted to statements of fundamental rights and basic principles. This led to ironies of fate such that the Independence of India Act, which subsequently formed the basis of the Indian constitution, is the longest act ever passed by the British Parliament, which is itself based on an unwritten constitution.
The Acts and Facts of Women’s Autonomy in India
Authors: Banerjee Paula
Published: November 2006

Any discussion of women's autonomy in India has to begin with the 19th century because it was at this time, by a conjuncture of events, that questions of women's rights assumed centre stage in debates on social reforms both in England and India. Although it was recognized by social reformers that something needed to be done to improve the condition of women in India, their actions were often not driven by any notion of gender justice or equality. That story has been much repeated, but what needs to be remembered is that these debates led to changes in the situation of women both in England and in India. More importantly, however, these debates led to the specific social construction of ‘woman’ as more a member of a community than an individual. This ensured that questions of women's autonomy were to be historically subsumed within religious and personal law, and were hardly ever treated as a matter of either individual right or justice. Even to this day women's autonomy remains hostage to personal and customary law.