bluuebunny/crossref_metadata_2025 huggingface dataset:
The NSMRL tri-word test of intelligibility (TTI)
Authors: Sergeant L. , Atkinson James E. , Lacroix Paul G.
Published: October 2005

A version of Griffiths’s Diagnostic Articulation Test (DAT) using three-word items is described. The test is applicable where monosyllabic words or sentence lists are undesirable or inappropriate. Each word of an item is drawn from a separate set of five monosyllabic real words differing only in the initial or final element. For each item, subjects underline one word in each of the three sets of words for that item on the answer sheet. The test examines reception of 150 words in 7 min as compared with 50 words in 5 min by the usual single-word format and preserves, moreover, the effects of gross temporal distortions and masking that occur within and between words in consecutive discourse. Discrimination scores for the tri-word test of intelligibility (TTI) as compared with the Modified Rhyme Test (MRT) and the C. I. D. sentence lists all taped with the same talker were lower when tested in quiet and even relatively lower in noise. The multiple-choice closed-set response permits easy administration, scoring, and analysis of confusions; enunciation of three semantically unrelated words in coarticulatory succession preserves interword transitions while limiting the effects of memory and linguistic redundance. The use of the DAT lists permits a somewhat more detailed analysis of errors than use of the three-word formant with the MRT as proposed by Williams et al. (Aviat. Space and Environm. Med. 47, 154–158 (1976). The NSMRL TTI is proposed as a relatively ease of administration and scoring are desirable.
Cochlear action potential threshold and single unit thresholds
Authors: Johnstone J. R. , Alder V. A. , Johnstone B. M. , Robertson D. , Yates G. K.
Published: October 2005

There is a close correlation between the sound pressure of tone burst required to affect a primary auditory neuron at its characteristic frequency and that which will produce a detectable N1 response at the same frequency. Units with thresholds from 80–0 db SPL (recorded from damaged and undamaged cochleas) were 0–20 dB ,respectively, more sensitive than the action potential response.
Development of noise and vibration ride comfort criteria
Authors: Dempsey Thomas K. , Leatherwood Jack D. , Clevenson Sherman A.
Published: October 2005

A laboratory investigation was directed at the development of criteria for the prediction of ride quality in a noise-vibration environment. The stimuli for the study consisted of octave bands of noise centered at 500 and 2000 Hz and vertical floor vibrations composed of either 5 Hz sinusoidal vibration, or random vibrations centered at 5 Hz and with a 5 Hz bandwidth. The noise stimuli were presented at A-weighted sound pressure levels ranging from ambient to 95 dB and the vibration at acceleration levels ranging from 0.02–0.13 grms. Results indicated that the total subjective discomfort response could be divided into two subjective components. One component consisted of subjective discomfort to vibration and was found to be a linear function of vibration acceleration level. The other component consisted of discomfort due to noise which varied logarithmically with noise level (power relationship). However, the magnitude of the noise discomfort component was dependent upon the level of vibration present in the combined environment. Based on the experimental results, a model of subjective discomfort that accounted for the interdependence of noise and vibration was developed. The model was then used to develop a set of criteria (constant discomfort) curves that illustrate the basic design tradeoffs available between noise and vibration.
Acoustic radiation force on a sphere in a quasistationary wave field—theory
Authors: Hasegawa Takahi
Published: October 2005

The acoustic radiation force on a solid sphere in a wave field in an inviscid fluid has been investigated theoretically and numerically taking into account the effects of elasticity of the sphere material for the following three cases: (I) the wave field is stationary, (II) the wave field is quasistationary, (III) the sound absorption in the sphere material is taken into account in each case above. The results show several features quite different from the rigid sphere solution.
Sound power radiated by a velocity monopole under reverberant and under freefield conditions
Authors: van Wulfften Palthe D. W. , de Vries D.
Published: October 2005

Sound powers measured with the same source under reverberant and freefield conditions need not necessarily agree. For velocity sources good agreement may be expected. However, discrepancies appear for lower frequencies. In this paper it is shown that these discrepancies may be attributed to the fact that the quantity determined in the reverberation chamber is not the true room average of the squared sound pressure. It is found that the power output of a sound source, measured in a reverberation chamber and an anechoic room, should approximately have the same value in both cases, when in the reverberation chamber averaging takes place over a sufficient number of source and microphone positions, where one of the transducers (source or microphone) is placed at positions all over the room (in the ’’central region’’ as well as near the boundaries), and the other one at ’’central positions’’ only. A previous experimental check confirms this idea partially.
Freeway noise and high-rise balconies
Authors: May Daryl N.
Published: October 2005

The sound levels on balconies above the 8th floor of high-rise buildings situated 200 ft or so from freeway edge-of-pavements were found to be about 10 dB higher than those occurring on the ground floor. Equivalent sound levels on these balconies during the day were in the range 70–80 dBA depending on the size of the freeway; these sound levels are as high as those at ground level 50 ft from the edge-of-pavements of the freeways concerned. However, the use of sound absorptive material on a normal front-walled balcony was shown to produce substantial noise reductions: treatment of the ceiling alone resulted in a 4–5 dB reduction, while a 7–8 dB reduction occurred with the addition of absorption equal, in Sabins, to a little over one-third the area of the balcony surfaces.
Nonuniform structural waveguides
Authors: Cole J. E. , Junger M. C.
Published: October 2005

Long-wavelength asymptotic solutions are formulated for axisymmetric compressional waves in waveguides whose cross section, Young’s modulus, and density vary as a power or an exponential function of the axial coordinate z. An unnecessary distinction which, however, is physically suggestive attributes to gradual backscattering signal attentuation associated with the increase of the latter two parameters. Attenuation associated with the increasing cross section can be envisioned as spreading loss. For both power and exponential changes, the solution displays an axial dependence on the coefficient giving the cross sectional area variation that is precisely twice that of either modulus or density coefficients.
Perceived sound quality of sound-reproducing systems
Authors: Gabrielsson Alf , Sjögren Håkan
Published: October 2005

Perceived sound quality of loudspeakers, headphones, and hearing aids was investigated by multivariate techniques from experimental psychology with the purpose (a) to find out and interpret the meaning of relevant dimensions in perceived sound quality, (b) find out the positions of the investigated systems in these dimensions, (c) explore the relations between the perceptual dimensions and the physical characteristics of the systems, and (d) explore the relations between the perceptual dimensions and overall evaluations of the systems. The resulting dimensions were interpreted as ’’clearness/distinctness,’’ ’’sharpness/hardness–softness,’’ ’’brightness–darkness,’’ ’’fullness–thinness,’’ ’’feeling of space,’’ ’’nearness,’’ ’’disturbing sounds,’’ and ’’loudness.’’ Their relations to physical variables were explored by studying the positions of the investigated systems in the respective dimensions. Their relations to overall evaluations were studied, and the implications of the investigations for continued research are discussed.
Scattering matrix for elastic waves. III. Application to spheroids
Authors: Varadan Vasundara V. , Varadan Vijay K.
Published: October 2005

Using the scattering matrix approach to elastic wave scattering, numerical results are presented for the scattering of P and S waves from prolate and oblate spheroidal cavities and inclusions embedded in an elastic solid for a wide range of wavelengths. The incident waves are plane harmonic waves incident obliquely to the axis of revolution of the spheroid.
A method for estimating the point of collision for transverse impact between a striker and a rod
Authors: Ikeda Osamu , Sato Takuso , Yamamoto Jiro , Manabe Akira
Published: October 2005

A method for estimating a forcing point on a metal rod is presented. This method is based on the spectral analyses of the signal detected by an accelerometer attached to the rod. First, the transfer function from a forcing point to the detector of the rod is derived; then by using it, an algorithm to estimate the forcing point is constructed. Experimental results clearly show the effectiveness of the method.
Super-resolution imaging using a sequential estimation of a hologram in an extended area from data obtained in a limited area
Authors: Sato Takuso , Sasaki Kimio , Uemura Kazuho
Published: October 2005

To reconstruct desired super-resolving images from data obtained in a limited area, a method of proper estimation of holograms in the extended area from the data is proposed. The estimation is carried out sequentially according to the accumulation of new data based on the least-mean-square method and the corresponding images are reconstructed at each stage. The process of the convergence of the reconstructed images is observed and the process is stopped when it is judged that the sequence of the images have been converged to give a final image. Thus, this method gives a super-resolution imaging in both senses of time and space. The algorithms for the estimation and image reconstruction, as well as the effects of noises for the method, are shown with some numerical examples.
A cylindrical-bubble model for the response of plant-tissue gas bodies to ultrasound
Authors: Miller Douglas L.
Published: October 2005

Many plant tissues contain gas in intercellular channels (gas bodies) which pulsate when insonated at megahertz frequencies, thus causing perturbations in nearby cells. Certain long, narrow gas bodies may be approximated acoustically by cylindrical gas bubbles with added stiffness due to the cell walls bounding the gas. Typical gas bodies in Elodea leaves and Vicia faba roots have four and three walls, respectively, which are about 0.5 μm thick and 6 μm wide. The Young’s modulus of the wall material is estimated to be 1010 dyn/cm2, and the walls are subject to a tensile stress of about 104 dyn/cm. Theoretical expressions for the effective stiffness and mass and the radiation, viscous, and thermal damping constants are obtained for free cylindrical bubbles and gas bodies. A 6-μm diam cylindrical bubble is expected to be resonant at 0.3 MHz with a total damping constant of 0.33. A four-walled gas body with 6 μm wide sides is expected to be resonant at 3 MHz, with a total damping constant of 0.48. In a typical plant tissue, significant gas-body activation and intracellular perturbation are expected over the range 0.6–12 MHz, making such tissues useful subjects for the study of the biological effects of ultrasound at these medically relevant frequencies.
Temporary threshold shifts in humans exposed to octave bands of noise for 16 to 24 hours
Authors: Mills John H. , Gilbert Robert M. , Adkins Warren Y.
Published: October 2005

Groups of human subjects were exposed in a diffuse sound field for 16–24 h to an octave-band noise centered at 4, 2, 1, or 0.5 kHz. Sound-pressure levels were varied on different exposure occasions. At specified times during an exposure, the subject was removed from the noise, auditory sensitivity was measured, and the subject was returned to the noise. Temporary threshold shifts (TTS) increased for about 8 h and then reached a plateau or asymptote. The relation between TTS and exposure duration can be described by a simple exponential function with a time constant of 2.1 h. In the frequency region of greatest loss, threshold shifts at asymptote increased about 1.7 dB for every 1 dB increase in the level of the noise above a critical level. Critical levels were empirically estimated to be 74.0 dB SPL at 4 kHz, 78 dB at 2 kHz, and 82 dB at 1 and 0.5 kHz. Except for the noise centered at 4.0 kHz, threshold shifts were maximal about 1/2 octave above the center frequency of the noise. A smaller second maximum was observed also at 7.0 kHz for the noise centered at 2.0 kHz, at 6.0 kHz for the noise centered at 1.0 kHz, and at 5.5 kHz for the noise centered at 0.5 kHz. After termination of the exposure, recovery to within 5 dB of pre-exposure thresholds was achieved within 24 h or less. Recovery can be described by a simple exponential function with a time constant of 7.1 h. The frequency contour defined by critical levels matches almost exactly the frequency contour defined by the E-weighting network.
An analysis of contoured crystal resonators operating in overtones of coupled thickness shear and thickness twist
Authors: Tiersten H. F. , Smythe R. C.
Published: October 2005

A previous treatment of overtone modes in trapped energy resonators is extended to the case of plates with slowly varying thickness. The resulting single scalar equation is applied in the analysis of plano-convex contoured quartz crystal resonators, and a lumped parameter representation of the admittance, which is valid in the vicinity of a resonance, is obtained. The analysis holds for the fundamental and anharmonic overtones of the fundamental and each harmonic overtone thickness mode. The influence of piezoelectric stiffening, electrode mass loading, and electrical shorting is included in the analysis. No adjustable parameters are required in the theory. Although the basic piezoelectric differential equation employed here is quite different from the ones that have been employed in similar applications heretofore, the analysis accounting for the contouring has appeared in the literature. It is shown that calculations based on the analysis agree extremely well with experimental results obtained with contoured AT-cut quartz crystal resonators.
The role of medial consonant transitions in word perception
Authors: Streeter Lynn A. , Nigro Georgia N.
Published: October 2005

In VCV nonsense forms (such as /εdε/), while both the CV transition and the VC transition are perceptible in isolation, the CV transition dominates identification of the stop consonant. Thus, the question arises, what role, if any, do VC transitions play in word perception? Stimuli were two-syllable English words in which the medial consonant was either a stop or a fricative (e.g., ’’feeding’’ and ’’gravy’’). Each word was constructed in three ways: (1) the VC transition was incompatible with the CV in either place, manner of articulation, or both; (2) the VC transition was eliminated and the steady-state portion of first vowel was substituted in its place; and (3) the original word. All versions of a particular word were identical with respect to duration, pitch contour, and amplitude envelope. While an intelligibility test revealed no differences among the three conditions, data from a paired comparison preference task and an unspeeded lexical decision task indicated that incompatible VC transitions hindered word perception, but lack of VC transitions did not. However, there were clear differences among the three conditions in the speeded lexical decision task for word stimuli, but not for nonword stimuli that were constructed in an analogous fashion. We discuss the use of lexical decision tasks for speech quality assessment and possible processes by which listeners recognize spoken words.
Measurements of low-velocity flow noise on pressure and pressure gradient hydrophones
Authors: Finger Robert A. , Abbagnaro Louis A. , Bauer Benjamin B.
Published: October 2005

A circular flow tank facility has been developed which features extremely low acoustic and vibration ambient conditions. This facility is described, operating procedures associated with its use are presented, and limitations in the measurement procedures are mentioned. The flow facility has been used to measure the noise output of pressure and pressure gradient hydrophones during actual flow conditions and results of these tests are presented and discussed.
THE CKM MATRIX AND CP VIOLATION
Authors: LIGETI ZOLTAN
Published: October 2005

The status of CP violation and the CKM matrix is reviewed. Direct CP violation in B decay has been established and the measurement of sin 2β in ψK modes reached 5% accuracy. I discuss the implications of these, and of the possible deviations of the CP asymmetries in b → s modes from that in ψK. The first meaningful measurements of α and γ are explained, together with their significance for constraining both the SM and new physics in [Formula: see text] mixing. I also discuss implications of recent developments in the theory of nonleptonic decays for B → πK rates and CP asymmetries, and for the polarization in charmless B decays to two vector mesons.
RECENT RESULTS OF NON-ACCELERATOR-BASED NEUTRINO EXPERIMENTS
Authors: WANG YIFANG
Published: October 2005

Recent results of non-accelerator-based experiments, including those of solar, atmospheric, and reactor neutrinos oscillations, neutrinoless double-beta decays, and neutrino magnetic moments, are reviewed. Future projects and their respective prospects are summarized.
OPTIMAL CONVERGENCE OF NON-OVERLAPPING SCHWARZ METHODS FOR THE HELMHOLTZ EQUATION
Authors: MAGOULÈS FRÉDÉRIC , PUTANOWICZ ROMAN
Published: September 2005

The non-overlapping Schwarz method with absorbing boundary conditions instead of the Dirichlet boundary conditions is an efficient variant of the overlapping Schwarz method for the Helmholtz equation. These absorbing boundary conditions defined on the interface between the subdomains are the key ingredients to obtain a fast convergence of the iterative Schwarz algorithm. In a one-way subdomains splitting, non-local optimal absorbing boundary conditions can be obtained and leads to the convergence of the Schwarz algorithm in a number of iterations equal to the number of subdomains minus one. This paper investigates different local approximations of these optimal absorbing boundary conditions for finite element computations in acoustics. Different approaches are presented both in the continuous and in the discrete analysis, including high-order optimized continuous absorbing boundary conditions, and discrete absorbing boundary conditions based on algebraic approximation. A wide range of new numerical experiments performed on unbounded acoustics problems demonstrate the comparative performance and the robustness of the proposed methods on general unstructured mesh partitioning.
LOCAL SPACE-TIME REFINEMENT FOR THE ONE-DIMENSIONAL WAVE EQUATION
Authors: HALPERN LAURENCE
Published: September 2005

We presented recently a new method to design a non-conforming space-time scheme for the wave equation.10 We introduce here a new concept of stability for domain decomposition, including perturbations on the boundaries of the numerical subdomains. We prove that our scheme is stable in that strong sense, and overall second order in time and space, for a constant velocity.
FETI-DPH: A DUAL-PRIMAL DOMAIN DECOMPOSITION METHOD FOR ACOUSTIC SCATTERING
Authors: FARHAT CHARBEL , AVERY PHILIP , TEZAUR RADEK , LI JING
Published: September 2005

A dual-primal variant of the FETI-H domain decomposition method is designed for the fast, parallel, iterative solution of large-scale systems of complex equations arising from the discretization of acoustic scattering problems formulated in bounded computational domains. The convergence of this iterative solution method, named here FETI-DPH, is shown to scale with the problem size, the number of subdomains, and the wave number. Its solution time is also shown to scale with the problem size. CPU performance results obtained for the acoustic signature analysis in the mid-frequency regime of mockup submarines reveal that the proposed FETI-DPH solver is significantly faster than the previous generation FETI-H solution algorithm.
AN INCOMPLETE LU PRECONDITIONER FOR PROBLEMS IN ACOUSTICS
Authors: GANDER MARTIN J. , NATAF FRÉDÉRIC
Published: September 2005

We present an incomplete LU preconditioner for solving discretized Helmholtz problems. The preconditioner is based on an analytic factorization of the Helmholtz operator. This allows us to take the physical properties of the acoustics problem modeled by the Helmholtz equation into account in the preconditioner. We show how the parameters in the preconditioner can be chosen in order to make it effective. Numerical experiments show that the new preconditioner leads to convergent iterative methods even for large wave numbers, and it outperforms classical ILU preconditioners by a large margin.
PROTECTING THE PUMP: Controlling Myocardial Inflammatory Responses
Authors: Taqueti Viviany R. , Mitchell Richard N. , Lichtman Andrew H.
Published: September 2005

▪ Abstract  Because of the anatomy, function, and nonregenerative nature of the myocardium, inflammation in this tissue is not well tolerated. Nevertheless, various diseases of the heart are characterized by inflammatory responses involving the effector mechanisms of innate and adaptive (lymphocyte-dependent) immunity. The innate immune response to ischemia-reperfusion injury is, by far, the most common cause of myocardial inflammation. Innate responses may have beneficial influences that preserve myocardial function in the short term but may be maladaptive in chronic states. Adaptive responses in the myocardium occur with infection or loss of tolerance, and lead to myocarditis. Given the narrow margin for benefit of cardiac inflammation, special regulatory mechanisms likely raise the threshold, compared to other tissues, for the induction and persistence of adaptive immune responses. These mechanisms include strong central and peripheral T cell tolerance to heart antigens and induction of anti-inflammatory feedback mechanisms involving cytokines such as interferon-γ.
CNG AND HCN CHANNELS: Two Peas, One Pod
Authors: Craven Kimberley B. , Zagotta William N.
Published: September 2005

▪ Abstract  Cyclic nucleotide–activated ion channels play a fundamental role in a variety of physiological processes. By opening in response to intracellular cyclic nucleotides, they translate changes in concentrations of signaling molecules to changes in membrane potential. These channels belong to two families: the cyclic nucleotide–gated (CNG) channels and the hyperpolarization-activated cyclic nucleotide–modulated (HCN) channels. The two families exhibit high sequence similarity and belong to the superfamily of voltage-gated potassium channels. Whereas HCN channels are activated by voltage and CNG channels are virtually voltage independent, both channels are activated by cyclic nucleotide binding. Furthermore, the channels are thought to have similar channel structures, leading to similar mechanisms of activation by cyclic nucleotides. However, although these channels are structurally and behaviorally similar, they have evolved to perform distinct physiological functions. This review describes the physiological roles and biophysical behavior of CNG and HCN channels. We focus on how similarities in structure and activation mechanisms result in common biophysical models, allowing CNG and HCN channels to be viewed as a single genre.
BRAINSTEM CIRCUITS REGULATING GASTRIC FUNCTION
Authors: Travagli R. Alberto , Hermann Gerlinda E. , Browning Kirsteen N. , Rogers Richard C.
Published: September 2005

▪ Abstract  Brainstem parasympathetic circuits that modulate digestive functions of the stomach are comprised of afferent vagal fibers, neurons of the nucleus tractus solitarius (NTS), and the efferent fibers originating in the dorsal motor nucleus of the vagus (DMV). A large body of evidence has shown that neuronal communications between the NTS and the DMV are plastic and are regulated by the presence of a variety of neurotransmitters and circulating hormones as well as the presence, or absence, of afferent input to the NTS. These data suggest that descending central nervous system inputs as well as hormonal and afferent feedback resulting from the digestive process can powerfully regulate vago-vagal reflex sensitivity. This paper first reviews the essential “static” organization and function of vago-vagal gastric control neurocircuitry. We then present data on the opioidergic modulation of NTS connections with the DMV as an example of the “gating” of these reflexes, i.e., how neurotransmitters, hormones, and vagal afferent traffic can make an otherwise static autonomic reflex highly plastic.
Cell type-specific activation of metabolism reveals that β-cell secretion suppresses glucagon release from α-cells in rat pancreatic islets
Authors: Takahashi Rui , Ishihara Hisamitsu , Tamura Akira , Yamaguchi Suguru , Yamada Takahiro , Takei Daisuke , Katagiri Hideki , Endou Hitoshi , Oka Yoshitomo
Published: September 2005

Abnormal glucagon secretion is often associated with diabetes mellitus. However, the mechanisms by which nutrients modulate glucagon secretion remain poorly understood. Paracrine modulation by β- or δ-cells is among the postulated mechanisms. Herein we present further evidence of the paracrine mechanism. First, to activate cellular metabolism and thus hormone secretion in response to specific secretagogues, we engineered insulinoma INS-1E cells using an adenovirus-mediated expression system. Expression of the Na+-dependent dicarboxylate transporter (NaDC)-1 resulted in 2.5- to 4.6-fold ( P < 0.01) increases in insulin secretion in response to various tricarboxylic acid cycle intermediates. Similarly, expression of glycerol kinase (GlyK) increased insulin secretion 3.8- or 4.2-fold ( P < 0.01) in response to glycerol or dihydroxyacetone, respectively. This cell engineering method was then modified, using the Cre- loxP switching system, to activate β-cells and non-β-cells separately in rat islets. NaDC-1 expression only in non-β-cells, among which α-cells are predominant, caused an increase (by 1.8-fold, P < 0.05) in glucagon secretion in response to malate or succinate. However, the increase in glucagon release was prevented when NaDC-1 was expressed in whole islets, i.e., both β-cells and non-β-cells. Similarly, an increase in glucagon release with glycerol was observed when GlyK was expressed only in non-β-cells but not when it was expressed in whole islets. Furthermore, dicarboxylates suppressed basal glucagon secretion by 30% ( P < 0.05) when NaDC-1 was expressed only in β-cells. These data demonstrate that glucagon secretion from rat α-cells depends on β-cell activation and provide insights into the coordinated mechanisms underlying hormone secretion from pancreatic islets.
Central orexin sensitivity, physical activity, and obesity in diet-induced obese and diet-resistant rats
Authors: Novak Colleen M. , Kotz Catherine M. , Levine James A.
Published: September 2005

Nonexercise activity thermogenesis (NEAT), the most variable component of energy expenditure, can account for differential capacities for human weight gain. Also highly variable, spontaneous physical activity (SPA) may similarly affect weight balance in animals. In the following study, we utilized the rat model of obesity, the diet-induced obese (DIO) rat, as well as the diet-resistant (DR) rat strain, to investigate how access to a high-fat diet alters SPA and the associated energy expenditure (i.e., NEAT). DIO and DR rats showed no differences in the amount of SPA before access to the high-fat diet. After 29 days on a high-fat diet, the DIO rats showed significant decreases in SPA, whereas the DR rats did not. Next, we wanted to determine whether the DIO and DR rats showed differential sensitivity to microinjections of orexin into the paraventricular nucleus of the hypothalamus (PVN). Unilateral guide cannulae were implanted, aimed at the PVN. Orexin A (0, 0.125, 0.25, and 1.0 nmol in 500 nl) was microinjected through the guide cannula into the PVN, then SPA and energy expenditure were measured for 2 h. Using the response to vehicle as a baseline, the DR rats showed significantly greater increase in NEAT compared with the DIO rats. These data indicate that diet-induced obesity is associated with decreases in SPA and a lack of increase in NEAT. A putative mechanism for changes in NEAT that accompany obesity is a decreased sensitivity to the NEAT-activating effects of neuropeptides such as orexin.
Exercise does not alter subcellular localization, but increases phosphorylation of insulin-signaling proteins in human skeletal muscle
Authors: Wilson Chris , Hargreaves Mark , Howlett Kirsten F.
Published: September 2005

The subcellular localization of insulin signaling proteins is altered by various stimuli such as insulin, insulin-like growth factor I, and oxidative stress and is thought to be an important mechanism that can influence intracellular signal transduction and cellular function. This study examined the possibility that exercise may also alter the subcellular localization of insulin signaling proteins in human skeletal muscle. Nine untrained males performed 60 min of cycling exercise (∼67% peak pulmonary O2uptake). Muscle biopsies were sampled at rest, immediately after exercise, and 3 h postexercise. Muscle was fractionated by centrifugation into the following crude fractions: cytosolic, nuclear, and a high-speed pellet containing membrane and cytoskeletal components. Fractions were analyzed for protein content of insulin receptor, insulin receptor substrate (IRS)-1 and -2, p85 subunit of phosphatidylinositol 3-kinase, Akt, and glycogen synthase kinase-3 (GSK-3). There was no significant change in the protein content of the insulin signaling proteins in any of the crude fractions after exercise or 3 h postexercise. Exercise had no significant effect on the phosphorylation of IRS-1 Tyr612in any of the fractions. In contrast, exercise increased ( P < 0.05) the phosphorylation of Akt Ser473and GSK-3α/β Ser9/21in the cytosolic fraction only. In conclusion, exercise can increase phosphorylation of downstream insulin signaling proteins specifically in the cytosolic fraction but does not result in changes in the subcellular localization of insulin signaling proteins in human skeletal muscle. Change in the subcellular protein localization is therefore an unlikely mechanism to influence signal transduction pathways and cellular function in skeletal muscle after exercise.
Immunolocalization of ectonucleotidases along the rat nephron
Authors: Vekaria Renu M. , Shirley David G. , Sévigny Jean , Unwin Robert J.
Published: September 2005

Evidence is accumulating that extracellular nucleotides act as autocrine/paracrine agents in most tissues, including the kidneys. Several families of surface-located enzymes, collectively known as ectonucleotidases, can degrade nucleotides. Using immunohistochemistry, we have examined the segmental distribution of five ectonucleotidases along the rat nephron. Perfusion-fixed kidneys were obtained from anesthetized male Sprague-Dawley rats. Cryostat sections of cortical and medullary regions were incubated with antibodies specific to the following enzymes: ectonucleoside triphosphate diphosphohydrolase (NTPDase) 1, NTPDase2, NTPDase3, ectonucleotide pyrophosphatase phosphodiesterase 3 (NPP3), and ecto-5′-nucleotidase. Sections were then costained with Phaseolus vulgaris erythroagglutinin (for identification of proximal tubules) and antibodies against Tamm-Horsfall protein (for identification of thick ascending limb), calbindin-D28k(for identification of distal tubule), and aquaporin-2 (for identification of collecting duct). The tyramide signal amplification method was used when the ectonucleotidase and marker antibody were raised in the same species. The glomerulus expressed NTPDase1 and NPP3. The proximal tubule showed prominent expression of NPP3 and ecto-5′-nucleotidase in most, but not all, segments. NTPDase2 and NTPDase3, but not NPP3 or ecto-5′-nucleotidase, were expressed in the thick ascending limb and distal tubule. NTPDase3, with some low-level expression of ecto-5′-nucleotidase, was also found in cortical and outer medullary collecting ducts. Inner medullary collecting ducts displayed low-level staining for NTPDase1, NTPDase2, NTPDase3, and ecto-5′-nucleotidase. We conclude that these ectonucleotidases are differentially expressed along the nephron and may play a key role in activation of purinoceptors by nucleotides and nucleosides.
α-MSH prevents impairment in renal function and dysregulation of AQPs and Na-K-ATPase in rats with bilateral ureteral obstruction
Authors: Li Chunling , Shi Yimin , Wang Weidong , Sardeli Chrysanthi , Kwon Tae-Hwan , Thomsen Klaus , Jonassen Thomas , Djurhuus Jens Christian , Knepper Mark A. , Nielsen Søren , Frøkiær Jørgen
Published: September 2005

The purpose of this study was to evaluate the effects of the anti-inflammatory hormone α-melanocyte-stimulating hormone (α-MSH) treatment on renal function and expression of aquaporins (AQPs) and Na-K-ATPase in the kidney in response to 24 h of bilateral ureteral obstruction (BUO) or release of BUO (BUO-R). In rats with 24-h BUO, immunoblotting revealed that downregulation of AQP2 and AQP3 was attenuated (AQP2: 38 ± 5 vs. 13 ± 4%; AQP3: 44 ± 3 vs. 19 ± 4% of sham levels; P < 0.05 ), whereas downregulation of Na-K-ATPase was prevented by α-MSH treatment (Na-K-ATPase: 94 ± 7 vs. 35 ± 5% of sham levels; P < 0.05). Immunocytochemistry confirmed the changes in AQP1 and Na-K-ATPase expression. Renal tubular cell apoptosis was confirmed in BUO kidneys, and α-MSH treatment virtually completely abolished apoptosis. Furthermore, we measured glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively. Forty-eight hours after BUO-R demonstrated that α-MSH treatment almost completely prevented the decrease in GFR (nontreated: 271 ± 50; α-MSH: 706 ± 85; sham: 841 ± 105 μl·min−1·100 g body wt−1, P < 0.05) and ERPF (nontreated: 1,139 ± 217; α-MSH: 2,598 ± 129; sham: 2,633 ± 457 μl·min−1·100 g body wt−1, P < 0.05). α-MSH treatment also partly prevented the downregulation of AQP1 and Na-K-ATPase expression in rats after BUO-R for 48 h. In conclusion, α-MSH treatment significantly prevents impairment in renal function and also prevents downregulation of AQP2, AQP3, and Na-K-ATPase during BUO or AQP1 and Na-K-ATPase after BUO-R, demonstrating a marked renoprotective effect of α-MSH treatment in conditions with urinary tract obstruction.
β-NAD is a novel nucleotide released on stimulation of nerve terminals in human urinary bladder detrusor muscle
Authors: Breen Leanne T. , Smyth Lisa M. , Yamboliev Ilia A. , Mutafova-Yambolieva Violeta N.
Published: September 2005

Endogenous nucleotides with extracellular functions may be involved in the complex neural control of human urinary bladder (HUB). Using HPLC techniques with fluorescence detection, we observed that in addition to ATP and its metabolites ADP, AMP and adenosine, electrical field stimulation (EFS; 4–16 Hz, 0.1 ms, 15 V, 60 s) of HUB detrusor smooth muscle coreleases novel nucleotide factors, which produce etheno-1 N6-ADP-ribose (eADPR) on etheno-derivatization at high temperature. A detailed HPLC fraction analysis determined that nicotinamide adenine dinucleotide (β-NAD+; 7.0 ± 0.7 fmol/mg tissue) is the primary nucleotide that contributes to the formation of eADPR. The tissue superfusates collected during EFS also contained the β-NAD+metabolite ADPR (0.35 ± 0.2 fmol/mg tissue) but not cyclic ADPR (cADPR). HUB failed to degrade nicotinamide guanine dinucleotide (NGD+), a specific substrate of ADP ribosyl cyclase, suggesting that the activity of this enzyme in the HUB is negligible. The EFS-evoked release of β-NAD+was frequency dependent and is reduced in the presence of tetrodotoxin (TTX; 0.3 μmol/l), ω-conotoxin GVIA (50 nmol/l), and botulinum neurotoxin A (BoNT/A; 100 nmol/l), but remained unchanged in the presence of guanethidine (3 μmol/l), ω-agatoxin IVA (50 nmol/l), or charbachol (1 μmol/l). Capsaicin (10 μmol/l) increased both the resting and EFS-evoked overflow of β-NAD+. Exogenous β-NAD+(1 μmol/l) reduced both the frequency and amplitude of spontaneous contractions. In conclusion, we detected nerve-evoked overflow of β-NAD+and ADPR in HUB. The β-NAD+/ADPR system may constitute a novel inhibitory extracellular nucleotide mechanism of neural control of the human bladder.
Is there an autoimmune process in bone? Gene expression studies in diabetic and nondiabetic BB rats as well as BB rat-related and -unrelated rat strains
Authors: Klöting Nora , Follak Niels , Klöting Ingrid
Published: September 2005

It is well known that type 1 diabetes is associated with a decrease in bone mass and delayed healing of fractures in human and in animal models of type 1 diabetes. Using well- and poorly compensated diabetic BB/O(ttawa) K(arlsburg) rats spontaneously developing insulin-dependent type 1 diabetes, it was recently shown that, in contrast to all other tissues studied, bone is most influenced by metabolic state and seems to be regulated in a manner different from other organs. Therefore, we studied the expression of additional genes ( Bmp-1, Bmp-4, Vegf, Bglap, Il-1b, Infg, Tnfa, Calca, Sp1, Yy1) in bone of nondiabetic BB rats compared with newly diagnosed and well- and poorly compensated diabetic rats as well as two nondiabetes-prone congenic BB.SHR rats, BB rat-related (WOKW) and -unrelated rat strains (F344). Six males of each group were euthanized, the tibial bone was removed, and total RNA was extracted, transcribed in complementary DNA, and used for real-time PCR. In a comparison of nondiabetic with diabetic groups, the relative gene expression was reduced by >80% in newly diagnosed and in well-compensated diabetic BB/OK rats. The gene expression in poorly compensated rats increased significantly in 7 of 10 genes and was comparable with those of nondiabetic BB/OK rats. In a comparison of gene expression between diabetes-prone BB/OK and nondiabetes-prone BB.1K, BB.4S, WOKW, and F344 rats, there were no significant differences between newly diagnosed and well-compensated BB/OK diabetic rats and nondiabetic BB.1K, BB.4S, WOKW, and F344 rats. On the basis of these findings, we concluded that spontaneous diabetes influences bone gene expression in BB/OK rats, which may be attributed to the genetically determined autoimmune process not only affecting pancreatic β-cells but also bone formation and resorption.
Chronic alcohol exposure alters transcription broadly in a key integrative brain nucleus for homeostasis: the nucleus tractus solitarius
Authors: Covarrubias Maria Yolanda , Khan Rishi L. , Vadigepalli Rajanikanth , Hoek Jan B. , Schwaber James S.
Published: September 2005

Chronic exposure to alcohol modifies physiological processes in the brain, and the severe symptoms resulting from sudden removal of alcohol from the diet indicate that these modifications are functionally important. We investigated the gene expression patterns in response to chronic alcohol exposure (21–28 wk) in the rat nucleus tractus solitarius (NTS), a brain nucleus with a key integrative role in homeostasis and cardiorespiratory function. Using methods and an experimental design optimized for detecting transcriptional changes less than twofold, we found 575 differentially expressed genes. We tested these genes for significant associations with physiological functions and signaling pathways using Gene Ontology terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, respectively. Chronic alcohol exposure resulted in significant NTS gene regulation related to the general processes of synaptic transmission, intracellular signaling, and cation transport as well as specific neuronal functions including plasticity and seizure behavior that could be related to alcohol withdrawal symptoms. The differentially expressed genes were also significantly enriched for enzymes of lipid metabolism, glucose metabolism, oxidative phosphorylation, MAP kinase signaling, and calcium signaling pathways from KEGG. Intriguingly, many of the genes we found to be differentially expressed in the NTS are known to be involved in alcohol-induced oxidative stress and/or cell death. The study provides evidence of very extensive alterations of physiological gene expression in the NTS in the adapted state to chronic alcohol exposure.
The queue‐length in GI/G/s queues
Authors: Le Gall Pierre
Published: September 2005

The distribution of the queue‐length in the stationary symmetrical GI/G/s queue is given with an application to the M/G/s queue, particularly in the case of the combination of several packet traffics, with various constant service times, to dimension the buffer capacity.
Forced vibration of a ball attached to a cable
Authors: Oliver Douglas , Giles Sammie
Published: September 2005

This work describes an analytic solution to predict the forced oscillation of a suspended cable and an attached ball. The oscillations are driven by a sinusoidal movement at the fixed end of the cable. This problem may be used in the verification of numerical software which is commonly used to design systems with suspended cables.
Robust high‐gain observer for nonlinear closed‐loop stochastic systems
Authors: Poznyak A. S. , Martínez-Guerra R. , Osorio-Cordero A.
Published: September 2005

In this paper, the problem of robust state observation is tackled. A high‐gain observer is employed to carry out the state estimation of a continuous time uncertain nonlinear system subject to external perturbations of stochastic nature. Unmodelled dynamics is assumed to be deterministic and belonging to an a priori known class of uncertainties.The control input is constructed based on the state estimates supplied by this observer. An upper bound for the estimation error and the states of this closed‐loop system is derived. It is shown to be a linear combination of all a priori given uncertainty levels and turns out to be “tight” (reachable). The proposed scheme is applied to a robot manipulator with unknown friction and inaccessible angular velocities.
Passivation and control of partially known SISO nonlinear systems via dynamic neural networks
Authors: Reyes-Reyes J. , Yu W. , Poznyak A. S.
Published: September 2005

In this paper, an adaptive technique is suggested to provide the passivity property for a class of partially known SISO nonlinear systems. A simple Dynamic Neural Network (DNN), containing only two neurons and without any hidden‐layers, is used to identify the unknown nonlinear system. By means of a Lyapunov‐like analysis the new learning law for this DNN, guarantying both successful identification and passivation effects, is derived. Based on this adaptive DNN model, an adaptive feedback controller, serving for wide class of nonlinear systems with an a priori incomplete model description, is designed. Two typical examples illustrate the effectiveness of the suggested approach.
New results in subspace‐stabilization control theory
Authors: Johnson C. D.
Published: September 2005

Subspace‐stabilization is a generalization of the classical idea of stabilizing motions of a dynamical system to an equilibrium state. The concept of subspace‐stabilization and a theory for designing subspace‐stabilizing control laws was introduced in a previously published paper. In the present paper, two new alternative methods for designing control laws that achieve subspace‐stabilization are presented. These two alternative design methods are based on: (i) a novel application of existing Linear Quadratic Regulator optimal‐control theory, and (ii) an algebraic method in which the control‐law is expressed as a linear feedback of certain “canonical variables.” In some cases, these new design methods may be more effective than existing ones. The results are illustrated by worked examples.
Synthesis of fixed‐architecture, robust H2 and H∞ controllers
Authors: Collins Emmanuel G. , Sadhukhan Debashis
Published: September 2005

This paper discusses and compares the synthesis of fixed‐architecture controllers that guarantee either robust H2 or H∞ performance. The synthesis is accomplished by solving a Riccati equation feasibility problem resulting from mixed structured singular value theory with Popov multipliers. Whereas the algorithm for robust H2 performance had been previously implemented, a major contribution described in this paper is the implementation of the much more complex algorithm for robust H∞ performance. Both robust H2 and H∞, controllers are designed for a benchmark problem and a comparison is made between the resulting controllers and control algorithms. It is found that the numerical algorithm for robust H∞ performance is much more computationally intensive than that for robust H2 performance. Both controllers are found to have smaller bandwidth, lower control authority and to be less conservative than controllers obtained using complex structured singular value synthesis.
Burgers′ equation with nonlinear boundary feedback: H1 stability, well‐posedness and simulation
Authors: Balogh Andras , Krstić Miroslav
Published: September 2005

We consider the viscous Burgers′ equation under recently proposed nonlinear boundary conditions and show that it guarantees global asymptotic stabilization and semiglobal exponential stabilization in H1 sense. Our result is global in time and allows arbitrary size of initial data. It strengthens recent results by Byrnes, Gilliam, and Shubov, Ly, Mease, and Titi, and Ito and Yan. The global existence and uniqueness of classical solutions follows from the general theory of quasi‐linear parabolic equations. We include a numerical result which illustrates the performance of the boundary controller.
Miss analysis in Lambert interceptions with application to a new guidance law
Authors: Park Joonhyung , Rhinehart Richard G. , Kabamba Pierre T.
Published: September 2005

For an interceptor that follows a Keplerian trajectory, we have obtained a closed‐form linear expression for the miss distance in terms of the perturbations of the booster cut‐off conditions, where the miss distance reflects the predicted miss at the Point of Closest Approach (PCA) between the interceptor and the target. We use this analysis result to develop a new guidance law which, in the absence of gravity, ensures (1) that the magnitude of the predicted PCA miss decays exponentially, and (2) that the magnitude of the relative velocity is constant. The same guidance law has been applied to interceptors flying in a gravity field. In the presence of random navigation errors in the new guidance law, the numerically simulated results show that increasing the guidance law gain increases the rms of the predicted PCA miss, which results in a degradation of the interception performance. A trade‐off in gain magnitude is required to prevent this degradation.