bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of sound propagation in a fluid through a screen of scatterers
Authors: Angel Y. C. , Aristégui C.
Published: June 2005

A multiple scattering analysis in a nonviscous fluid is developed in detail in order to predict the coherent sound motion in the presence of disordered heterogeneities, such as particles, fibers, bubbles, or contrast agents. Scatterers can be homogeneous, layered, shell-like with encapsulated liquids or gas, nonabsorbing, or absorbing, and can take a wide variety of shapes. A priori imposed limitations or physical assumptions are absent in the derivation, whether they concern the expected response of the fluid-scatterer mixture, the scatterer size relative to wavelength, or the scatterer concentration or the screen thickness. However, as in any multiple scattering formulation, a closure assumption is invoked. Closed-form results for the backscattered and forward-scattered wave motions on either side of the screen of scatterers are obtained. The fluid-scatterer mixture is shown to behave as an effective dissipative medium from the standpoint of the coherent motion. It is found that the effective medium is fully described once two parameters are determined: the effective wave number and the reflection coefficient for the associated half-space screen. Remarkably, both parameters depend only on the far-field scattering properties of a single scatterer.
Classification and identification of recorded and synthesized impact sounds by practiced listeners, musicians, and nonmusicians
Authors: Lutfi Robert A. , Oh Eunmi , Storm Eileen , Alexander Joshua M.
Published: June 2005

Three experiments were conducted to test the viability of a low-parameter modal model for synthesizing impact sounds to be used in commercial and psychoacoustic research. The model was constrained to have four physically based parameters dictating the amplitude, frequency, and decay of modes. The values of these parameters were selected by ear to roughly match the recordings of ten different resonant objects suspended by hand and struck with different mallets. In experiment 1, neither 35 professional musicians nor 187 college undergraduates could identify which of the two matched sounds was the real recording with better than chance accuracy, though significantly better than chance performance was obtained when modal parameters were selected without the previously imposed physical constraints. In experiment 2, the undergraduates identified the source corresponding to the recorded and synthesized sounds with the same level of accuracy and largely the same pattern of errors. Finally, experiment 3 showed highly practiced listeners to be largely insensitive to changes in the acoustic waveform resulting from an increase in the number of free parameters used in the modal model beyond 3. The results suggest that low-parameter, modal models might be exploited meaningfully in many commercial and research applications involving human perception of impact sounds.
Noise screening effects of balconies on a building facade
Authors: Tang S. K.
Published: June 2005

The insertion loss and its spectrum due to a rectangular balcony on a building facade in the presence of sound reflection and scattering from adjacent balconies were examined using a scale model. The front panel of the balcony dictates the screening performance, while the side walls of the balcony are found to be insignificant. Balconies without a front panel do not provide acoustic protection in the presence of upper balcony reflection, especially for a distant noise source. Sound amplifications are also observed in many cases. In addition, the shapes of the insertion loss spectra are found to depend on the elevation angle of the balcony. Significant correlations between the A-weighted balcony insertion losses with this angle are found in the absence of upper balcony reflections. With such reflection, an angle defined using the balcony configuration and source position correlates within engineering tolerance to the insertion losses.
The effect of rate of stimulation on perception of spectral shape by cochlear implantees
Authors: McKay Colette M. , Henshall Katherine R. , Hull Alicia E.
Published: June 2005

The effect of rate of stimulation on spectral shape perception was measured in six users of the Nucleus CI24 cochlear implant. Three spectral shapes were created by using three profiles of current across seven electrode positions. Each current profile was replicated in three stimuli that interleaved stimulus pulses across the seven electrodes with cycle rates (rate per electrode) of 450, 900, and 1800Hz. The stimulus space resulting from a multidimensional scaling experiment showed a clear dimension related to the rate of stimulation that was orthogonal to the dimension related to the spectral shapes. A second experiment was performed with the same subjects to investigate whether the perceptual dimension related to rate in Experiment 1 could be attributed to different perceptual flatness of the profiles at different rates. In Experiment 2, the rate of stimulation was fixed at 900Hz and three profiles were created for each spectral shape that differed in flatness. This experiment did not, however, result in an independent perceptual dimension related to the flatness of the profile. In conclusion, rate of stimulation provided an independent perceptual dimension in the multiple-electrode stimuli, in spite of the rates being not discriminable or barely discriminable in single-electrode stimulation.
Real-time synthesis of clarinet-like instruments using digital impedance models
Authors: Guillemain Philippe , Kergomard Jean , Voinier Thierry
Published: June 2005

A real-time synthesis model of wind instruments sounds, based upon a classical physical model, is presented. The physical model describes the nonlinear coupling between the resonator and the excitor through the Bernoulli equation. While most synthesis methods use wave variables and their sampled equivalent in order to describe the resonator of the instrument, the synthesis model presented here uses sampled versions of the physical variables all along the synthesis process, and hence constitutes a straightforward digital transposition of each part of the physical model. Moreover, the resolution scheme of the problem (i.e., the synthesis algorithm) is explicit and all the parameters of the algorithm are expressed analytically as functions of the physical and the control parameters.
Perceptual effects of dialectal and prosodic variation in vowels
Authors: Fox Robert Allen , Jacewicz Ewa , Hatcher Kristin , Salmons Joseph
Published: June 2005

As was reported earlier [Fox et al., J. Acoust. Soc. Am. 114, 2396 (2003)], certain vowels in the Ohio and Wisconsin dialects of American English are shifting in different directions. In addition, we have found that the spectral characteristics of these vowels (e.g., duration and formant frequencies) changed systematically under varying degrees of prosodic prominence, with somewhat different changes occurring within each dialect. The question addressed in the current study is whether naive listeners from these two dialects are sensitive to both the dialect variations and to the prosodically induced spectral differences. Listeners from Ohio and Wisconsin listened to the stimulus tokens [beIt] and [bεt] produced in each of three prosodic contexts (representing three different levels of prominence). These words were produced by speakers from Ohio or from Wisconsin (none of the listeners were also speakers). Listeners identified the stimulus tokens in terms of vowel quality and indicated whether it was a good, fair, or poor exemplar of that phonetic category. Results showed that both phonetic quality decisions and goodness ratings were systematically and significantly affected by speaker dialect, listener dialect, and prosodic context. Implications of source and nature of ongoing vowel changes in these two dialects will be discussed. [Work partially supported by NIDCD R03 DC005560-01.]
Data on directionality measures of adaptive systems
Authors: Nilsson Michael J. , Wellington Jim , Kirsch Jay , Bray Victor
Published: June 2005

Directionality has become the dominant method to improve the signal-to-noise ratio in hearing aids. Quantification of differences in the amount of directionality between systems has become a source of scientific, as well as marketing, interest. Developments in directionality now involve signal processing methods that interact with directional microphones based upon adaptive algorithms in order to broaden the appeal and usefulness of these systems. The ANSI S3.35 revision for 2004 improves the methodology for relating measures of directionality to expected performance when using many systems, but fails to address measurements using these adaptive systems. These systems respond differently depending upon the type, volume, or location of a stimulus, and will generate different results using the single noise source technique included in the standard compared to diffuse noise conditions. This presentation presents data using various measurement techniques to quantify the differences between directional systems. Different types of adaptive systems will be identified that vary in their interaction with the ANSI methods and an understanding of how measurements change with changes in technique will be presented.
Review of the development of concrete pavement surface types and their acoustic performance with time
Authors: Scofield Larry A
Published: June 2005

Roadways have been constructed out of concrete pavements in the United States since the late 1800s. Numerous surface textures have been produced including burlap drag, astroturf, uniformly and random transverse tined, longitudinally tined, and both profile and whisper diamond grinding processes. Each surface evolved for specific reasons during the historical development of Portland Cement Concrete Pavements (PCCP).This paper reviews the development of these various surface texture types and the reasons for their evolution. In addition, results from both far field and near field acoustic testing are presented to evaluate the ‘‘acoustic’’ performance of these surfaces over time.For five surface types, 1/24 octave analysis were conducted on CPX data obtained with a single tire. The spectrum of each of these surface types is presented for comparison. For three of the surfaces, speed gradient testing, ranging between 25–75 MPH was conducted. 1/24 octave analysis of each of these runs was conducted so that that any speed induced spectrum shifts could be observed.The results to date indicate that the adverse tonal properties of some PCCP surfaces can be eliminated through diamond grinding and prevented by not constructing transverse tined PCCP.
Dual-backplate capacitive aeroacoustic microphone
Authors: Martin David T. , Liu Jian , Kadirvel Karthik , Fox Robert M. , Sheplak Mark , Nishida Toshikazu
Published: June 2005

High-performance instrumentation grade microphones are a crucial component for aeroacoustic measurements. This paper presents the design, fabrication, and characterization of a MEMS dual-backplate capacitive microphone designed for aeroacoustic applications where small size, high dynamic range, and high bandwidth are key requirements. The microphone features a 230-micron radius, 2-micron air gaps, and a 118-dB dynamic range. Experimental results indicate a sensitivity of 0.282 mV/Pa, a linear response up to 160 dB, a noise floor of 42 dB at 1 kHz in a 1-Hz bin, and a measured resonant frequency of 230 kHz. A flat frequency response was measured up to 20 kHz in an 8.5×8.5−mm square rigid-walled acoustic plane-wave tube. The microphone was designed using an equivalent lumped-element model, simulated using finite-element methods, and fabricated using the SUMMiT V process at Sandia National Laboratories. Details on the acoustic and electrical characterization, fabrication process, and packaging will be described in the presentation.
THE INFLUENCE OF AN INDIVIDUAL OPINION IN THE SZNAJD MODEL
Authors: KLIETSCH NINA
Published: June 2005

The method of Damage Spreading was used to simulate the influence that a single persons' change of opionion has on the consensus opinion built up in a population if one assumes opinions to form according to the Sznajd Model. The results confirm the intuitive assumption that there is hardly any chance for one person to change the consensus, that the effect of this change dies out after a certain time and its range decreases with time. The consensus times were compared and it turned out that the consensus can be delayed or accelerated by this slight modification and that the amount of the difference in the consensus times obeys a certain power law as well as the lifetime of the effect. Moreover, two scaling laws concerning temporal and spatial aspects could be observed up to a certain size of population.
Microglia, Apoptosis and Interleukin-1β Expression in the Effect ofSophora JaponicaL. on Cerebral Infarct Induced by Ischemia-Reperfusion in Rats
Authors: Lao Chih-Jui , Lin Jaung-Geng , Kuo Jon-Son , Chao Pei-Dawn Lee , Cheng Chin-Yi , Tang Nou-Ying , Hsieh Ching-Liang
Published: June 2005

Sophora Japonica L. (SJ) is a traditional Chinese herb used to cool blood, stop bleeding and to treat hemorrhoids with bleeding. Although several recent studies found that both SJ and Ginkgo biloba have the same components of quercetin and rutin, only Ginkgo biloba has been widely used to treat cerebrovascular disorders and dementia in humans. This study investigated the effect of SJ on cerebral infarct in rats. A total of 66 Sprague-Dawley (SD) rats were studied. Focal cerebral infarct was established by occluding the bilateral common carotid arteries and the right middle cerebral artery for 90 minutes. After 24 hours of reperfusion, the neurological status was evaluated. The rats were then killed, and brain tissue was stained with 2,3,5-triphenyl-tetrazolium chloride. The grading scale of neurological deficit and the ratio of cerebral infarction area were used as an index to evaluate the effect of SJ on cerebral infarct. In addition, the number of ED1 and interleukin-1β immunostaining positive cells, and apoptotic cells were measured in the cerebral infarction zone. The results indicated that pre-treatment with 100 or 200 mg/kg SJ and post-treatment with 200 mg/kg SJ significantly reduced the grade of neurological deficit and the ratio of cerebral infarction area. In addition, pre-treatment with 200 mg/kg SJ also significantly reduced ED1 and interleukin-1β immunostaining positive cells, and apoptotic cells in ischemia-reperfusion cerebral infarct rats. This study demonstrated that SJ could reduce the cerebral infarction area and neurological deficit induced by ischemia-reperfusion in rats, suggesting its potential as a treatment for cerebral infarct in humans. This effect of SJ involves its suppressive action of microglia, interleukin-1β and apoptosis.
Effect of Curcuma Herbs on Vasomotion and Hemorheology in Spontaneously Hypertensive Rat
Authors: Goto Hirozo , Sasaki Yohei , Fushimi Hirotoshi , Shibahara Naotoshi , Shimada Yutaka , Komatsu Katsuko
Published: June 2005

Curcuma herbs have a vasodilator effect. The effects of C. longa, which induces only endothelium-independent vasodilatation, and C. zedoaria, which induces both endothelium-dependent and -independent vasodilatation, were studied on vasomotion and hemorheology in spontaneously hypertensive rats. Spontaneously hypertensive eight-week-old male rats were assigned to five groups. For 12 weeks, the control group received standard chow. The 3%CL (C. longa) group received standard chow containing 3% (wt/wt) C. longa. The 1%CZ and 3%CZ (C. zedoaria) groups received standard chow containing 1% and 3% (wt/wt) C. zedoaria, respectively. The captoril group received standard chow and 100 mg/kg/day of captoril in drinking water. Blood pressure, vasomotion, hemorheology, etc. were examined. Systolic blood pressure of the 3%CZ and captoril groups decreased significantly as compared to the control group. Acetylcholine-induced endothelium-dependent relaxations of the 3%CZ and captoril groups were increased to a greater degree, significantly, than the control group. When testing xanthine oxidase-induced contraction, the 3%CZ group was significantly decreased as compared to the control group. Low shear stress of whole blood viscosity showed the 3%CL and 3%CZ groups to be decreased significantly compared to the control group. Thus, Curcuma herbs have hypotensive and protective effect on the endothelium in spontaneously hypertensive rats. Especially, C. zedoaria is more effective than C.longa, and its mechanism is thought to be related to a radical scavenging effect and improvement of hemorheology.
Genomic Expression for Rat Model of Damp Obstruction in Chinese Medicine: Application of Microarray Technology
Authors: Huang G. Steve , Hong Meng-Yen
Published: June 2005

Damp obstruction refers to the stagnation of vital energy (qi) caused by dampness resulting in dysfunction of body and limbs movement, as well as impairment of spleen and stomach digestive function. Damp obstruction is the dampness-induced imbalance of five elements; thus it serves as an ideal model for genomic study using cDNA microarray. We have performed microarray analyses to major organs of damp-obstructed rats. Cluster analysis for the expression profiles of major organs indicated that spleen, stomach, and kidney respond to dampness differently from heart, liver, lung, and brain. Gene expression profile specific to each element or group of elements was also identified. Our results are consistent with the philosophy of Chinese medicine that the five elements, metal (lung), wood (liver), water (kidney), fire (heart), and earth (spleen and stomach) coordinate by subjugation or restriction to maintain a healthy, physiological state. This is the first time that a powerful genomic tool was applied to probe the ancient theory of Chinese medicine.
Post-ischemic Treatment with Toki-Shakuyaku-San (Tang-Gui-Shao-Yao-San) Prevents the Impairment of Spatial Memory Induced by Repeated Cerebral Ischemia in Rats
Authors: Pu Fengling , Mishima Kenichi , Egashira Nobuaki , Akiyoshi Yuki , Liu An-Xin , Sano Kazunori , Irie Keiichi , Ishibashi Daisuke , Hatip-Al-Khatib Izzettin , Iwasaki Kiyo , Kurauchi Kouji , Iwasaki Katsunori , Fujiwara Michihiro
Published: June 2005

Previously we have reported that Toki-shakuyaku-san (TSS) ameliorated the impairment of spatial memory induced by single cerebral ischemia (1 × 10 minutes ) and scopolamine, a muscarinic receptor antagonist. In this experiment, we studied the effect of TSS on repeated cerebral ischemia (2 × 10 minutes , 1-hour interval) induced impairment of spatial memory and neuronal injury in rats. The 8-day post-ischemic treatment with TSS (30–300 mg/kg) was administered p.o. once per day. TSS dose-dependently prevented the impairment of spatial memory, neuronal death and TUNEL positive cells induced by repeated cerebral ischemia. In order to determine the mechanism of TSS, we also studied the effect of TSS on GluR2 mRNA, one of the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) receptor subunits. Repeated cerebral ischemia significantly decreased GluR2 flop mRNA at 1 and 3 days after the occlusion. TSS (300 mg/kg) significantly suppressed the decrease in GluR2 flop at 3 days after repeated cerebral ischemia. These results suggested that the TSS has neuroprotective action which may be indirectly mediated by the AMPA receptor, and TSS may be beneficial for the treatment of cerebrovascular dementia.
Is There Any Energy Transfer During Acupuncture?
Authors: Lee Myeong Soo , Lee Yong-Heum , Shin Byung-Cheul , Jeong Dong-Myong , Kim Mo Kyung , Eo Yoon-Gi , Ko Su-Bok
Published: June 2005

Acupuncture therapy is based on the principle of restoring equilibrium of the body's energy state by regulating the flow of Qi in the corresponding meridians and acupoints. The purpose of this study was to determine whether bio-energy transfer occurs during acupuncture of the meridians. We treated 20 normal healthy subjects with acupuncture and measured changes in the direct current (DC) potential between the stomach meridian points ST-39 and ST-37 in response to invasive insertion of a needle at ST-36. Using a crossover study design, the practitioner performed the procedure on each subject once with bare (uncovered) hands (ABH) and once wearing surgical gloves (ASH) to shield the electric energy transfer. ABH produced a response pattern to each stimulation, whereas ASH produced a response pattern only to the first step. ABH elicited a significantly higher response potential than did ASH ( p < 0.001). These results suggest that there may be bio-energy (Qi) transfer during acupuncture along the meridians. This transferred bio-energy (Qi) seems to act as an electromotive force, which is purported to remove the stagnation or blockage of energy and restore an equilibrium state.
HEAVY BOSON PRODUCTION THROUGH THE COLLISION OF AN ULTRAHIGH-ENERGY NEUTRINO ON A TARGET NUCLEON
Authors: GARCÍA-HIDALGO R. M. , ROSADO A.
Published: June 2005

We discuss W and Z production through the deep inelastic [Formula: see text]-scattering in the context of the standard model SU (3)C× SU (2)L× U (1) of the strong and electroweak interactions. We find the cross-section rates for the process [Formula: see text] for the case of ultrahigh-energy neutrinos (1014 eV ≤Eν≤1017 eV ) colliding on a target nucleon [Formula: see text]. We also calculate [Formula: see text] in order to compare it with [Formula: see text]. We show that the cross-section rates for the process [Formula: see text] did not become so large as one could expect, due to the strong destructive interference between the two different mechanisms which contribute at the lowest order in α (keeping only photon exchange diagrams). This destructive interference mechanism is inherent to the standard model as a non-Abelian gauge theory.
THE UNIFIED EQUATION OF STATE FOR DARK MATTER AND DARK ENERGY
Authors: WANG WEI , GUI YUANXING , ZHANG SUHONG , GUO GUANGHAI , SHAO YING
Published: June 2005

We assume that dark matter and dark energy satisfy the unified equation of state: p = B(z)ρ, with p = pdE, ρ = ρdm+ρdE, where the pressure of dark matter pdm = 0 has been taken into account. A special function [Formula: see text] is presented, which can well describe the evolution of the universe. In this model, the universe will end up with a Big Rip. By further simple analysis, we know other choices of the function B can also describe the universe but lead to a different doomsday.
GENERIC CHIRAL SUPERFIELD MODEL ON NON-ANTICOMMUTATIVE $\mathcal{N}=1/2$ SUPERSPACE
Authors: AZORKINA O. D. , BUCHBINDER I. L. , BANIN A. T. , PLETNEV N. G.
Published: June 2005

We consider the generic non-anticommutative model of chiral–antichiral superfields on [Formula: see text] superspace. The model is formulated in terms of an arbitrary Kählerian potential, chiral and antichiral superpotentials and can include the non-anticommutative supersymmetric sigma-model as a partial case. We study a component structure of the model and derive the component Lagrangian in an explicit form with all auxiliary fields contributions. We show that the infinite series in the classical action for generic non-anticommutative model of chiral–antichiral superfields in D = 4 dimensions can be resumed in a compact expression which can be written as a deformation of standard Zumino's Lagrangian and chiral superpotential. Problem of eliminating the auxiliary fields in the generic model is discussed and the first perturbative correction to the effective scalar potential is obtained.
A SIMPLE SIGNAL OF NONCOMMUTATIVE SPACE
Authors: ACATRINEI CIPRIAN SORIN
Published: June 2005

We propose a simple low-energy classical experiment in which the effects of noncommutativity can be clearly separated from commutative physics. The ensuing bound on the noncommutative scale is remarkable, especially in view of its elementary derivation.
EFFECTS OF THE BIAS-CONTROLLED GRID ON PERFORMANCES OF THE CORONA POLING SYSTEM FOR ELECTRO-OPTIC POLYMERS
Authors: HONG JIANXUN , CHEN JIANPING , LI XINWAN , YE AILUN
Published: June 2005

The corona poling system for electro-optic polymers with a bias-controlled grid is experimentally studied. The relationship between the corona threshold voltage and the grid bias voltage is researched. There is a minimum in the corona threshold voltage versus grid bias voltage curve. Effects of the grid bias voltage, the mesh size and the grid electrode position on performances of the poling system are discussed and analyzed. The experimental results show that the grid electrode can enlarge the corona discharge dynamic range and control the poling current in a wide range, grid electrodes with different mesh sizes and grid-plate gaps have different effects on performances of the poling system, and the grid electrode should be near the plate electrode to acquire stable corona discharge.
QUANTUM PROPERTIES OF LIGHT IN LINEAR MEDIA WITH TIME-DEPENDENT PARAMETERS BY LEWIS–RIESENFELD INVARIANT OPERATOR METHOD
Authors: CHOI JEONG RYEOL , YEON KYU HWANG
Published: June 2005

We investigated exact quantum states of the light confined in cubes filled with conductive media whose parameters are explicitly dependent on time and the light propagating under periodic boundary condition by making use of the LR (Lewis–Riesenfeld) invariant operator method. The choice of Coulomb gauge in the charge free space allowed us to evaluate quantized electric and magnetic fields by expanding only the vector potential, since the scalar potential is zero. We also described the fields with a spectrum of continuous mode, which can be obtained by setting the side L to infinity.
ENTROPIC NON-TRIVIALITY, THE CLASSICAL LIMIT AND GEOMETRY-DYNAMICS CORRELATIONS
Authors: KOWALSKI A. M. , MARTIN M. T. , PLASTINO A. , ROSSO O. A.
Published: June 2005

The quantum-classical limit together with the associated onset of chaos is employed here in order to illustrate the importance of a proper choice of distance in probability space if one wishes to describe dynamical properties from the information theory viewpoint.
AVALANCHE DYNAMICS OF THE FINANCIAL MARKET
Authors: ZHOU PEI-LING , YANG CHUN-XIA , ZHOU TAO , XU MIN , LIU JUN , WANG BING-HONG
Published: June 2005

A parsimonious percolation model for stock market is proposed, of which the avalanche dynamics agree with the real-life one as well. We have also investigated how the interaction parameter p affects the price dynamics. Simulation results about the formation of the bullish/bearish market and corresponding avalanche taking place in the market indicate that the magnified "herd behavior" resulting from the evolution of p may be the origin of the observed avalanche phenomena.
ORDINAL SUMS IN INTERVAL-VALUED FUZZY SET THEORY
Authors: DESCHRIJVER GLAD
Published: June 2005

Interval-valued fuzzy sets form an extension of fuzzy sets which assign to each element of the universe a closed subinterval of the unit interval. This interval approximates the "real", but unknown, membership degree. In fuzzy set theory, an important class of triangular norms is the class of those that satisfy the residuation principle. A method for constructing t-norms that satisfy the residuation principle is by using the ordinal sum theorem. In this paper, we construct the ordinal sum of t-norms on [Formula: see text], where [Formula: see text] is the underlying lattice of interval-valued fuzzy set theory, in such a way that if the summands satisfy the residuation principle, then the ordinal sum does too.
THE PREPARATION AND CHARACTERIZATION OF HIGHLY EFFICIENT TITANIUM OXIDE–BASED PHOTOFUNCTIONAL MATERIALS
Authors: Anpo Masakazu , Dohshi Satoru , Kitano Masaaki , Hu Yun , Takeuchi Masato , Matsuoka Masaya
Published: June 2005

▪ Abstract  Recent research trends of the preparation and characterization of highly efficient titanium oxide–based photocatalysts are reviewed on the basis of studies done in our laboratory. Special attention is focused on the preparation and characterization of active sites of highly dispersed titanium oxide species within mesoporous matrices and on titanium oxide–based binary catalysts such as Ti/Si and Ti/B oxides and unique visible light-responsive second-generation TiO2 photocatalysts prepared by an advanced metal-ion-implantation and RF magnetron sputtering deposition method. Highly dispersed titanium oxide species within mesoporous frameworks and titanium oxide–based binary catalysts exhibit high and unique photocatalytic activities for various reactions, such as the direct decomposition of NOx. These species also have photo-induced superhydrophiric properties. It is of significance that visible light-responsive TiO2 photocatalysts can be applied to the decomposition of NOx in air and the degradation of pollutants in water, as well as to the splitting of water under UV and visible light irradiation.
Hypothyroidism increases Fos immunoreactivity in cholinergic neurons of brain medullary dorsal vagal complex in rats
Authors: Yuan Pu-Qing , Yang Hong
Published: June 2005

Hypo- or hyperthyroidism is associated with autonomic disorders. We studied Fos expression in the medullary dorsal motor nucleus of the vagus (DMV), nucleus tractus solitarii (NTS), and area postrema (AP) in four groups of rats with different thyroid states induced by a combination of drinking water and daily intraperitoneal injection for 1–4 wk: 1) tap water and vehicle; 2) 0.1% propylthiouracil (PTU) and vehicle; 3) PTU and thyroxine (T4; 2 μg/100 g); and 4) tap water and T4(10 μg/100 g). The numbers of Fos immunoreactive (IR) positive neurons in the DMV, NTS, and AP were low in euthyroid rats but significantly higher in the 4-wk duration in hypothyroid rats, which were prevented by simultaneous T4replacement. Hyperthyroidism had no effect on Fos expression in these areas. There were significant negative correlations between T4levels and the numbers of Fos-IR-positive neurons in the DMV ( r = −0.6388, P < 0.008), NTS ( r = −0.6741, P < 0.003), and AP ( r = −0.5622, P < 0.004). Double staining showed that Fos immunoreactivity in the DMV of hypothyroid rats was mostly localized in choline acetyltransferase-containing neurons. Thyroid hormone receptors α1 and β2 were localized in the observed nuclei. These results indicate that thyroid hormone influences the DMV/NTS/AP neuronal activity, which may contribute to the vagal-related visceral disorders observed in hypothyroidism.
Effects of long-term treatment with growth hormone-releasing peptide-2 in the GHRH knockout mouse
Authors: Alba Maria , Fintini Danilo , Bowers Cyril Y. , Parlow A. F. , Salvatori Roberto
Published: June 2005

Growth hormone (GH) secretagogues (GHS) stimulate GH secretion in vivo in humans and in animals. They act on the ghrelin receptor, expressed in both the hypothalamus and the pituitary. It is unknown whether GHSs act predominantly by increasing the release of hypothalamic GH-releasing hormone (GHRH) or by acting directly on the somatotroph cells. We studied whether a potent GHS could stimulate growth in the absence of endogenous GHRH. To this end, we used GHRH knockout (GHRH-KO) mice. These animals have proportionate dwarfism due to severe GH deficiency (GHD) and pituitary hypoplasia due to reduced somatotroph cell mass. We treated male GHRH-KO mice for 6 wk (from week 1 to week 7 of age) with GH-releasing peptide-2 (GHRP-2, 10 μg sc twice a day). Chronic treatment with GHRP-2 failed to stimulate somatotroph cell proliferation and GH secretion and to promote longitudinal growth. GHRP-2-treated mice showed an increase in total body weight compared with placebo-treated animals, due to worsening of the body composition alterations typical of GHD animals. These data demonstrate that GHRP-2 failed to reverse the severe GHD caused by lack of GHRH.
Aristides Leão’s discovery of cortical spreading depression
Authors: Somjen G. G.
Published: June 2005

This essay looks at the historical significance of three APS classic papers that are freely available online:

Leão AAP. Spreading depression of activity in the cerebral cortex. J Neurophysiol 7: 359–390, 1944 ( http://jn.physiology.org/cgi/reprint/7/6/359 ).

Leão AAP. Pial circulation and spreading depression of activity in the cerebral cortex. J Neurophysiol 7: 391–396, 1944 ( http://jn.physiology.org/cgi/reprint/7/6/391 ).

Leão AAP. Further observations on the spreading depression of activity in the cerebral cortex. J Neurophysiol 10: 409–414, 1947 ( http://jn.physiology.org/cgi/reprint/10/6/409 ).
Sensory Representation of Temperature in Mosquito Warm and Cold Cells
Authors: Gingl Ewald , Hinterwirth Armin , Tichy Harald
Published: June 2005

A pair of antagonistic thermoreceptive cells is associated with each of two peg-in-pit sensilla located on the antennal tip of Aedes aegypti. One, the warm cell, responds to rapid warming with a sudden increase in the rate of discharge. The other, a cold cell, responds to rapid cooling with a sudden increase in the discharge rate. When temperature changes are provided by oscillating changes in the convective heat contained in the stimulating air stream, the oscillating discharge rates of both cell types are in advance of the oscillations in temperature and slightly behind the oscillations in the rate of temperature change. Analysis of these phase relationships shows that both cell types respond not only to the actual temperature at particular instants in time (instantaneous temperature) but also to the rate with which temperature changes. Individual responses are therefore ambiguous and signal tendencies rather than precise instantaneous values. When the temperature oscillations are delivered by changes in radiation power, however, the oscillating discharge rates of the warm and cold cells are in step with the oscillations in temperature. Here, individual responses signal instantaneous values of temperature rather than tendencies. The power of radiant heat required to modulate the discharge rates is relatively high, suggesting that infrared radiation is not a significant cue in distant host location.
Influence of IFN-γ on gene expression in normal human bronchial epithelial cells: modulation of IFN-γ effects by dexamethasone
Authors: Pawliczak Rafal , Logun Carolea , Madara Patricia , Barb Jennifer , Suffredini Anthony F. , Munson Peter J. , Danner Robert L. , Shelhamer James H.
Published: June 2005

Interferon gamma (IFN-γ) plays a role in a variety of lung inflammatory responses, and corticosteroids are frequently employed as a treatment in these conditions. Therefore, the effect of IFN-γ, of the corticosteroid dexamethasone (Dex), or of both on gene expression was studied in normal human bronchial epithelial (NHBE) cells. NHBE cells were exposed to medium alone, IFN-γ (300 U/ml), Dex (10−7M), or both IFN-γ and Dex for 8 or 24 h. Gene expression was examined using oligonucleotide microarrays. A principal components analysis demonstrated that the IFN-γ treatment effect was the primary source of differences in the data. With a 5% false discovery rate, of the 66 genes upregulated by IFN-γ by twofold or greater at 8 h and 287 genes upregulated at 24 h, coincubation with Dex inhibited the expression of 2 genes at 8 h and 45 genes at 24 h. Prominent among these were cytokines and secreted proteins. Dex cotreatment increased expression of 65 of the 376 genes that were inhibited by IFN-γ by 50% at 24 h. The majority of these genes encode cell cycle or nuclear proteins. Dex alone increased the expression of only 22 genes and inhibited the expression of 7 genes compared with controls at 24 h. The effect of Dex on IFN-γ-induced changes suggests a specific, targeted effect on IFN-γ responses that is substantially greater than the effect of Dex alone. Dex had little effect on the immediate early response to IFN-γ but a significant effect on the late responses.
Structure and Function of CLCA Proteins
Authors: Loewen Matthew E. , Forsyth George W.
Published: June 2005

CLCA proteins were discovered in bovine trachea and named for a calcium-dependent chloride conductance found in trachea and in other secretory epithelial tissues. At least four closely located gene loci in the mouse and the human code for independent isoforms of CLCA proteins. Full-length CLCA proteins have an unprocessed mass ratio of ∼100 kDa. Three of the four human loci code for the synthesis of membrane-associated proteins. CLCA proteins affect chloride conductance, epithelial secretion, cell-cell adhesion, apoptosis, cell cycle control, mucus production in asthma, and blood pressure. There is a structural and probable functional divergence between CLCA isoforms containing or not containing β4-integrin binding domains. Cell cycle control and tumor metastasis are affected by isoforms with the binding domains. These isoforms are expressed prominently in smooth muscle, in some endothelial cells, in the central nervous system, and also in secretory epithelial cells. The isoform with disrupted β4-integrin binding (hCLCA1, pCLCA1, mCLCA3) alters epithelial mucus secretion and ion transport processes. It is preferentially expressed in secretory epithelial tissues including trachea and small intestine. Chloride conductance is affected by the expression of several CLCA proteins. However, the dependence of the resulting electrical signature on the expression system rather than the CLCA protein suggests that these proteins are not independent Ca2+-dependent chloride channels, but may contribute to the activity of chloride channels formed by, or in conjunction with, other proteins.
Controlling Cell Behavior Electrically: Current Views and Future Potential
Authors: McCaig Colin D. , Rajnicek Ann M. , Song Bing , Zhao Min
Published: June 2005

Direct-current (DC) electric fields are present in all developing and regenerating animal tissues, yet their existence and potential impact on tissue repair and development are largely ignored. This is primarily due to ignorance of the phenomenon by most researchers, some technically poor early studies of the effects of applied fields on cells, and widespread misunderstanding of the fundamental concepts that underlie bioelectricity. This review aims to resolve these issues by describing: 1) the historical context of bioelectricity, 2) the fundamental principles of physics and physiology responsible for DC electric fields within cells and tissues, 3) the cellular mechanisms for the effects of small electric fields on cell behavior, and 4) the clinical potential for electric field treatment of damaged tissues such as epithelia and the nervous system.
Von der Schuldfrage zur Fehlerkultur in der Medizin
Authors: Haller U. , Welti S. , Haenggi D. , Fink D.
Published: June 2005

Die Anzahl der Haftpflichtfälle, aber auch die einzelnen Schadenvolumina angeblicher Behandlungsfehler steigen stetig an. Spektakuläre Gerichtsurteile, insbesondere aus den USA, fördern diesen Trend. Wo Menschen arbeiten, werden Fehler gemacht. Das Gesundheitswesen ist besonders anfällig und weist ein hohes Fehlerpotential auf. Deshalb muss dem Risikomanagement in den Spitälern höchste Priorität eingeräumt werden. Die Vorbereitung für die Einführung eines «Critical Incident Reporting» (CIR) als Fehlermeldesystem braucht Zeit und bedingt einen Kulturwandel, weil vielerorts die dafür notwendige Vertrauensbasis zuerst geschaffen werden muss. Es geht beim CIR nicht darum, Schuldige zu suchen und sie zu bestrafen, sondern Fehlerquellen aufzudecken, um diese zu eliminieren. Am Departement für Anästhesiologie des Universitätsspitals Basel wurde ein elektronisches Fehlermeldesystem entwickelt, welches in Zusammenarbeit mit der FMH jeder Fachgesellschaft erlaubt, anonym und auf elektronischer Basis an einem CIR-System (CIRS) teilzunehmen, um so einen möglichst grossen Datenpool zu schaffen und damit überhaupt Aussagen zum Ausmass und zur Art von Fehlerquellen in der Medizin zu ermöglichen. Die Schweizerische Gesellschaft für Gynäkologie und Geburtshilfe führt nach einem Pilotprojekt in den Jahren 2000–2004 jetzt schrittweise das «CIRS Medical» der FMH ein. Mangels ausdrücklicher gesetzlicher Schutzgarantien in unserem Land sind solche Programme verletzlich gegenüber richterlichen Zugriffen. Umso wichtiger sind elegante Datenerfassung und kluge Datenvernichtung. Spitaldirektionen bzw. Spitalleitungen sind aufgerufen, sich mit den Zwischenfällen zu befassen, welchen Systemfehler zugrunde liegen.
Individuals Seeking Treatment for Cannabis-Related Problems in Ontario: Demographic and Treatment Profile
Authors: Urbanoski Karen A. , Strike Carol J. , Rush Brian R.
Published: June 2005

We report on the extent of cannabis treatment-seeking within an addiction treatment system in Canada. Data represent all new admissions in fiscal year 2000 to substance abuse treatment agencies in the province of Ontario (n = 47,995). Analyses examine the prevalence of cannabis problems by demographic and treatment characteristics and provide contrasts with other client subgroups (alcohol, cocaine, and opiates). Clients reporting cannabis as their primary problem substance (13%) were more likely to be male, single, under age 20 and in high school. Legal system involvement and school- or family-based pressure to enter treatment were commonly reported, but less so by older cannabis clients. The distinctiveness of these clients within the larger treatment system raises questions of the relevance to cannabis clients of interventions designed for other substance-abusing populations.
Risk Factors and Predictors of Human Immunodeficiency Virus Infection among Injection Drug Users
Authors: Backmund Markus , Meyer Kirsten , Henkel Claudia , Reimer Jens , Wächtler Martin , Schütz Christian G.
Published: June 2005

Background/Aim: Injection drug users (IDUs) have a high risk of acquiring an infection with the human immunodeficiency virus (HIV). To improve counseling and prevention, a better understanding of risk factors and predictors for an infection must be gained. This retrospective study has the aim to determine the risk factors for acquisition of HIV infection other than sharing of needles/syringes. Methods: The study population consisted of all patients admitted to the detoxification unit between 1991 and 1996 who met ICD-10 criteria for opioid dependency, who reported to share needles, and who agreed to have an antibody test. Possible risk factors were assessed by interview. Cross tables based on bivariate logistic regression were constructed to estimate the relative odds. Multiple logistic regression modeling procedures were used to adjust possible confounding factors. Results: A total of 1,049 out of 1,656 patients admitted were included into the study. 4.8% of the patients were HIV-1 seropositive. The prevalence was higher among older patients and among patients living with a significant other substance drug user with substance dependency, after a longer duration of drug use, and after coinfection with hepatitis B virus and/or hepatitis C virus (HCV). Using multiple logistic regression analyses and including all individually significant risk factors, we found only coinfection with HCV to remain significant. 92% of the HIV-infected patients were also HCV infected. In the group younger than 23 years of age, a total of 53.5% of the IDUs were still seronegative for HIV, hepatitis A and B virus, and HCV. Conclusions: Despite the high rate of HCV coinfection (92%) in HIV-infected patients, we found more than 50% of IDUs younger than 23 years to be neither infected with HCV nor with HIV. Early prevention strategies against infectious diseases should especially focus on young IDUs.
Oral Testosterone in Male Rats and the Development of Experimental Autoimmune Encephalomyelitis
Authors: Macció Daniela R. , Calfa Gastón , Roth German A.
Published: June 2005

Objectives: Considering that sex steroids can influence the immune system, we studied the development of experimental autoimmune encephalomyelitis (EAE), a T-cell-mediated autoimmune disease of the central nervous system, and the concomitant cell-mediated immunity in gonadally intact and gonadectomized male Wistar rats given testosterone supplementation. Methods/Results: Sham-operated rats and surgically castrated animals were orally self-administered with vehicle or testosterone added in the water bottle for 20 days before EAE induction. The androgenic effect of oral testosterone self-administration was evidenced by changes in body weight, and in the weights of androgen-dependent testes and seminal vesicles. Testosterone administration reduced the incidence of clinical signs of EAE in sham-operated animals and reversed the clinical symptoms of the disease associated with castrated EAE animals. The clinical signs observed in the different groups correlated with changes in delayed-type hypersensitivity and mononuclear cell-proliferative responses to the encephalitogenic myelin basic protein. Moreover, testosterone but not cholesterol supplementation in vitro suppressed the proliferative response of mononuclear cells to myelin basic protein suggesting that testosterone may affect specific immune functions through direct actions on immune cells. Finally, self-administration of testosterone induced also elevated corticosterone levels that in sham-operated rats correlated with the low incidence of the disease and in gonadectomized animals could be involved in the remission of clinical symptoms of EAE. Conclusions: These results suggest that orally self-administered testosterone can modulate specific cellular immune responses and serum corticosterone levels leading to changes in the development of EAE.
Derivation of Meropenem Dosage in Patients Receiving Continuous Veno-Venous Hemofiltration Based on Pharmacodynamic Target Attainment
Authors: Kuti Joseph L. , Nicolau David P.
Published: June 2005

Background: Dosage recommendations for antibiotics in patients receiving continuous veno-venous hemofiltration (CVVH) should be based on pharmacodynamic requirements. For meropenem, this would be achieving appropriate time above the minimum inhibitory concentration (T > MIC). We employed Monte Carlo simulation to calculate the bactericidal target attainment for various dosing regimens of meropenem against Pseudomonas aeruginosa and Acinetobacter species. Methods: Target attainment at 40% T > MIC was calculated for 5,000 simulated subjects receiving meropenem 1,000 mg every 12 and 8 h, and 500 mg every 12, 8 and 6 h. Pharmacokinetics were extrapolated from primary literature sources utilizing similar methods of CVVH. MIC data for P. aeruginosa and Acinetobacter species were derived from the US 2003 MYSTIC study. Target attainment at the breakpoint of 4 µg/ml was also calculated. Results: Only regimens of 1,000 mg every 8 h and 500 mg every 6 h essentially achieve 100% target attainment at the breakpoint. However, due to higher peak concentrations, 1,000 mg every 8 h is able to attain improved target attainment against more resistant populations of P. aeruginosa and Acinetobacter species, thus providing the greatest probability of bactericidal exposure. Conclusion: Meropenem 1,000 mg every 8 h optimizes the pharmacodynamic profile in patients undergoing CVVH. Lower doses or increased dosing intervals should not be advocated for inpatients receiving this renal replacement technique.