bluuebunny/crossref_metadata_2025 huggingface dataset:
A scattering-chamber approach for solving finite rough surface scattering problems
Authors: Fawcett John A.
Published: September 2005

In this paper a new method is derived for the computation of scattering from a finite, rough free surface. The free surface is infinite in extent but only a portion of it is rough. In order to reduce the amount of numerical computation for such a problem, it is desirable to restrict the computations to the interval of roughness, even for remote sources and receivers. This can be easily done in the case that the rough portion of the surface is only directed into the surrounding fluid medium. In this case, the use of the appropriate half-space Green’s function will restrict the integral equation to the interval of roughness only. However, for general deformations this Green’s function cannot be used. The use of truncated integral equations utilizing the free space Green’s function is discussed. An alternate approach is then described. A system of boundary conditions is derived for a finite curve containing the interval of roughness and a surrounding contour in the fluid half-space. The resulting equations are solved using the method of wave-field superposition. The derived method is also easily generalized to the case that the rough surface under consideration is the upper boundary of a waveguide.
Matched field processing with contrast maximization
Authors: Shin K. C. , Kim J. S.
Published: September 2005

The high sidelobe level of the ambiguity surface has been a major drawback of matched field processing in ocean waveguides compared to the free space beamforming. In this paper, a contrast-maximized optimization scheme that enhances the contrast between the acoustic power output of the source region and the power output of the total region of interest is presented. The method utilizes the signal vectors determined from the contrast-maximizing formulation. Through numerical simulation and oceanic data analysis, the presented algorithm is shown to be effective in improving the contrast between the target and the averaged background sidelobe level. It was also shown that, even when the resolution of the source region in conventional matched field processing is degraded due to severe bottom attenuation, the resolution of the source is not affected in the contrast-maximized method. The same principle and method can be applied to the time-reversal processing to maintain the focal size in an ocean environment with high bottom attenuation.
Two modes of motion of the alligator lizard cochlea: Measurements and model predictions
Authors: Aranyosi A. J. , Freeman Dennis M.
Published: September 2005

Measurements of motion of an in vitro preparation of the alligator lizard basilar papilla in response to sound demonstrate elliptical trajectories. These trajectories are consistent with the presence of both a translational and rotational mode of motion. The translational mode is independent of frequency, and the rotational mode has a displacement peak near 5kHz. These measurements can be explained by a simple mechanical system in which the basilar papilla is supported asymmetrically on the basilar membrane. In a quantitative model, the translational admittance is compliant while the rotational admittance is second order. Best-fit model parameters are consistent with estimates based on anatomy and predict that fluid flow across hair bundles is a primary source of viscous damping. The model predicts that the rotational mode contributes to the high-frequency slopes of auditory nerve fiber tuning curves, providing a physical explanation for a low-pass filter required in models of this cochlea. The combination of modes makes the sensitivity of hair bundles more uniform with radial position than that which would result from pure rotation. A mechanical analogy with the organ of Corti suggests that these two modes of motion may also be present in the mammalian cochlea.
Data-based mode extraction with a partial water column spanning array
Authors: Walker S. C. , Roux Philippe , Kuperman W. A.
Published: September 2005

In a shallow ocean waveguide the acoustic field can be characterized by depth-dependent modes propagating in range with an associated propagating wavenumber. Though recently developed methods for determining the modes from recorded acoustic data alone without ocean or bottom modeling have shown promise, they are only applicable when the acoustic field is sampled over the entire water column. This paper presents a method for determining the acoustic modes from measured data alone when the field is sampled over only a portion of the water column. The method requires broadband sources at many ranges, e.g., a moving source, in order to construct the frequency-wavenumber (f-k) structure of the waveguide. Because modal propagation is dispersive, the modes are characterized by a discrete set of wavenumbers that vary continuously with frequency. Due to the discreteness of the modal wavenumbers, it is possible to isolate the modes in the f-k domain and extract them individually with a singular value decomposition (SVD). Because the modes are extracted individually the full-spanning and degeneracy limitations of the SVD are removed. Theory, simulation, and laboratory data confirm the process.
Contribution of harmonicity and location to auditory object formation in free field: Evidence from event-related brain potentials
Authors: McDonald Kelly L. , Alain Claude
Published: September 2005

The contribution of location and harmonicity cues in sound segregation was investigated using behavioral reports and source waveforms derived from the scalp-recorded evoked potentials. Participants were presented with sounds composed of multiple harmonics in a free-field environment. The third harmonic was either tuned or mistuned and could be presented from the same or different location from the remaining harmonics. Presenting the third harmonic at a different location than the remaining harmonics increased the likelihood of hearing the tuned or slightly (i.e., 2%) mistuned harmonic as a separate object. Partials mistuned by 16% of their original value “pop out” of the complex and were paralleled by an object-related negativity (ORN) that superimposed the N1 and P2 components. For the 2% mistuned stimuli, the ORN was present only when the mistuned harmonic was presented at a different location than the remaining harmonics. Presenting the tuned harmonic at a different location also yielded changes in neural activity between 150 and 250ms after sound onset. The behavioral and electrophysiological results indicate that listeners can segregate sounds based on harmonicity or location alone. The results also indicate that a conjunction of harmonicity and location cues contribute to sound segregation primarily when harmonicity is ambiguous.
Simulation of ultrasound propagation through bovine cancellous bone using elastic and Biot’s finite-difference time-domain methods
Authors: Hosokawa A.
Published: September 2005

The propagation of ultrasonic pulse waves in bovine cancellous bone has been numerically analyzed in two dimensions by using two finite-difference time-domain (FDTD) methods: the commonly used elastic FDTD method and an FDTD method extended with Biot’s theory for a porous elastic solid saturated with viscous fluid. Both FDTD results were compared with the results of previous experiments by Hosokawa and Otani [J. Acoust. Soc. Am. 101, 558–562 (1997)], in which the Biot’s fast and slow longitudinal waves were clearly identified. It was difficult to analyze both the fast and slow waves with the elastic FDTD method because of the inadequate 2D model of cancellous bone. On the other hand, in Biot’s FDTD results that consider the pore fluid motion relative to the solid frame, both waves could be clearly observed. The experimental and simulated values of the speeds of these waves were in good agreement. Using the modified Biot’s FDTD equations containing the possible attenuations for the fast wave other than the viscous loss due to the pore fluid motion, the amplitude ratio of the slow wave to the fast wave largely increased with the porosity, which also agrees with the experimental results.
A continuous wave method for ultrasonic characterization of liquid materials
Authors: Deblock Yves , Campistron Pierre , Nongaillard Bertrand
Published: September 2005

This paper describes a method for measuring the velocity and attenuation of high-frequency sound waves traveling through liquid materials. This method is based on the measurement of the forward scattering parameter (S21) of the acoustic system composed of two transducers and the liquid between them. The acoustic parameters are obtained from the analysis of S21 in the time domain. Various experiments using distilled water as the liquid sample have been carried out. They show the influence on the measurement sensitivity of receiver detection bandwidth, liquid thickness, and difference of temperature between the room and the test cell. The method was used for the measurement of the attenuation and velocity of mixtures of alcohol and water.
Aerodynamic transfer of energy to the vocal folds
Authors: Thomson Scott L. , Mongeau Luc , Frankel Steven H.
Published: September 2005

The aerodynamic transfer of energy from glottal airflow to vocal fold tissue during phonation was explored using complementary synthetic and numerical vocal fold models. The synthetic model was fabricated using a flexible polyurethane rubber compound. The model size, shape, and material properties were generally similar to corresponding human vocal fold characteristics. Regular, self-sustained oscillations were achieved at a frequency of approximately 120 Hz. The onset pressure was approximately 1.2 kPa. A corresponding two-dimensional finite element model was developed using geometry definitions and material properties based on the synthetic model. The finite element model upstream and downstream pressure boundary conditions were based on experimental values acquired using the synthetic model. An analysis of the fully coupled fluid and solid numerical domains included flow separation and unsteady effects. The numerical results provided detailed flow data that was used to investigate aerodynamic energy transfer mechanisms. The results support the hypothesis that a cyclic variation of the orifice profile from a convergent to a divergent shape leads to a temporal asymmetry in the average wall pressure, which is the key factor for the achievement of self-sustained vocal fold oscillations.
Production and perception of clear speech in Croatian and English
Authors: Smiljanić Rajka , Bradlow Ann R.
Published: September 2005

Previous research has established that naturally produced English clear speech is more intelligible than English conversational speech. The major goal of this paper was to establish the presence of the clear speech effect in production and perception of a language other than English, namely Croatian. A systematic investigation of the conversational-to-clear speech transformations across languages with different phonological properties (e.g., large versus small vowel inventory) can provide a window into the interaction of general auditory-perceptual and phonological, structural factors that contribute to the high intelligibility of clear speech. The results of this study showed that naturally produced clear speech is a distinct, listener-oriented, intelligibility-enhancing mode of speech production in both languages. Furthermore, the acoustic-phonetic features of the conversational-to-clear speech transformation revealed cross-language similarities in clear speech production strategies. In both languages, talkers exhibited a decrease in speaking rate and an increase in pitch range, as well as an expansion of the vowel space. Notably, the findings of this study showed equivalent vowel space expansion in English and Croatian clear speech, despite the difference in vowel inventory size across the two languages, suggesting that the extent of vowel contrast enhancement in hyperarticulated clear speech is independent of vowel inventory size.
On the sound field of an oscillating disk in a finite open and closed circular baffle
Authors: Mellow Tim , Kärkkäinen Leo
Published: September 2005

Equations describing the radiation characteristics of a rigid disk in a finite open baffle are derived using a method similar to that used by Streng for a circular membrane based upon the dipole part of the Kirchhoff–Helmholtz boundary integral formula. In this case, however, a power series solution to the radiation integral is derived in order to eliminate the need for numerical integration. Hence, a set of simultaneous equations is obtained by simply equating the coefficients of the power series, which leads to two mathematical functions, one real and one imaginary, that can be applied to any radial velocity distribution. This provides an alternative method to obtain the sound scattered by a disk or the complementary hole in an infinite resilient screen according to Babinet’s principle. Using the principle of superposition (or Gutin concept), it is shown how the sound radiation characteristics of a disk radiating from just one side can be obtained by combining the radiation field of a disk in a finite baffle with that of a disk in an infinite baffle. This one-sided radiator may be interpreted as a disk in a thin, circular enclosure.
Radiative transfer equation for multiple diffraction
Authors: Reboul Emeline , Le Bot Alain , Perret-Liaudet Joël
Published: September 2005

This paper aims to apply the radiative transfer method to acoustical diffraction by obstacles. Some fictitious sources are introduced at diffracting wedges and a transfer equation based on energy balance determines the diffracted powers. It leads to a set of linear equations on diffracted powers which can be solved in a finite number of steps. It is then possible to calculate the diffracted field anywhere. Some applications to diffraction by obstacles of various shapes are presented. Results of this method are compared with Geometrical Theory of Diffraction and BEM reference calculations. It is shown that this method is particularly efficient in case of multiple diffraction where the ray-tracing technique involves an infinite number of rays between a source and a receiver point.
Effects of bite blocks and hearing status on vowel production
Authors: Lane Harlan , Denny Margaret , Guenther Frank H. , Matthies Melanie L. , Menard Lucie , Perkell Joseph S. , Stockmann Ellen , Tiede Mark , Vick Jennell , Zandipour Majid
Published: September 2005

This study explores the effects of hearing status and bite blocks on vowel production. Normal-hearing controls and postlingually deaf adults read elicitation lists of ∕hVd∕ syllables with and without bite blocks and auditory feedback. Deaf participants’ auditory feedback was provided by a cochlear prosthesis and interrupted by switching off their implant microphones. Recording sessions were held before prosthesis was provided and one month and one year after. Long-term absence of auditory feedback was associated with heightened dispersion of vowel tokens, which was inflated further by inserting bite blocks. The restoration of some hearing with prosthesis reduced dispersion. Deaf speakers’ vowel spaces were reduced in size compared to controls. Insertion of bite blocks reduced them further because of the speakers’ incomplete compensation. A year of prosthesis use increased vowel contrast with feedback during elicitation. These findings support the inference that models of speech production must assign a role to auditory feedback in error-based correction of feedforward commands for subsequent articulatory gestures.
Two case studies: QuietRock QR-530 drywall panels in new and remediated multifamily construction
Authors: Tinianov Brian D.
Published: September 2005

Reliable acoustical isolation continues to be a high risk element of contemporary multifamily construction. Traditional construction techniques, offering potentially high acoustical performance, exist but may be compromised during typical construction or occupation. This paper presents two case studies using a new class of construction material—drywall panels employing constrained layer damping. QuietRock QR-530 damped gypsum board panels are used in a new construction project and as part of a remediation treatment. In a first study, QR-530 panels were used as a drywall alternative in a 2×6, semistaggered, framed wall separating luxury condominiums. Field evaluation per ASTM E36 revealed a normalized noise isolation class of 56. In a second case study, a single layer of QuietRock was applied directly to an existing single stud assembly in a resort hotel. Before and after testing yielded a change of 14 points, raising the noise isolation class from 36 to 50. This paper reviews the details of the test cases and the underlying physical principals of the subject materials.
The interaction between specificity and linguistic contrast
Authors: Nielsen Kuniko
Published: September 2005

Previous studies have shown listeners’ ability to remember fine phonetic details [e.g., Mullennix et al., 1989], providing support for the episodic view of speech perception. The imitation paradigm [Goldinger, 1998, Shockley et al., 2004], in which subjects’ speech is compared before and after they are exposed to target speech (= study phase) has shown that subjects shift their production in the direction of the target. Our earlier results [Nielsen, 2005] showed that the imitation effect for extended VOT was generalized to new stimuli as well as to a new segment, suggesting that the locus of the imitation effect can be smaller than individual words or segments. The current study aims to further investigate how experienced speech input interacts with linguistic representations, by testing whether the imitation effect is observed when the modeled stimuli have reduced VOT (which could introduce linguistic ambiguity). In other words, do speakers imitate and generalize shorter VOT even if the change might impair linguistic contrasts? To address this question, the study phase includes words with initial /p/ with reduced VOT, while the pre- and post-study production list includes (1) the modeled words, (2) the modeled segments /p/ in new words, and (3) the new segment /k/.
Double throat pressure pulsation dampener for oil-free screw compressors
Authors: Lucas Michael J.
Published: September 2005

This paper describes a recent invention at Ingersoll-Rand for reducing the pressure pulsations in an oil-free screw compressor. Pressure pulsation is a term used in the air compressor industry to describe the rapid change in pressure with time measured in the downstream piping of the air compressor. The pulsations are due to the rapid opening and closing of the screws as the compressed air is eject from the compressor into the piping system. The pulsations are known to produce excessive noise levels and high levels of vibration in the piping system. Reducing these pulsations is critical to achieving a quiet running compressor. This paper will describe the methodology used to analyze the data and show both computational and experimental results achieved using the pulsation dampener. A patent for this design has been filed with the US patent office.
PERFORMANCE OF A COHERENT JET COOLANT SYSTEM IN NON-CONTINUOUS DRESS CREEP-FEED GRINDING OF INCONEL 718
Authors: STEFFEN JOACHIM , BAUER ROBERT , WARKENTIN ANDREW , BECZE ED
Published: September 2005

In this work, the effect of the degree of jet coherency on the occurrence of workpiece burn when creep-feed grinding Inconel 718 under non-continuous dress conditions is studied. Different degrees of jet coherency are compared on the basis of the maximum material removal rate achievable before workpiece burn occurs. The comparison is performed at different coolant flow rates as well as at different distances between nozzle and grinding zone. It is found that a more coherent jet results in considerably higher possible material removal rates before workpiece burn occurs. Furthermore, it is determined that nozzle distance from the grinding zone and nozzle orientation and position with respect to the grinding zone, using a coherent jet, does not affect cooling performance. It is also shown that an increase in flow rate will increase cooling performance but only up to a point.
EVALUATION OF TOTAL THROUGHPUT TIME FOR AN ELECTRONICS PRODUCTION LINE BY SIMULATION AND FUZZY PERT NETWORK
Authors: LI K. H. , LEE S. F. , LI C. K. , LU DAWEI
Published: September 2005

Layout decision is an important issue in electronics manufacturing process. A good layout with better arrangement of assembly machines will increase overall efficiency and throughput. It is not uncommon that many industrial companies in Hong Kong do not use systematic layout planning methods for their layout decisions. This paper aims at developing a simulation model to analyze the best layout decision for an electronics manufacturing company. Finally, a simplified fuzzy PERT network framework is proposed to model a Surface Mount Technology (SMT) production line for calculating the fuzzy throughput time of the SMT line under fuzzy processing parameters.
A GENERAL RELATION BETWEEN SUMS OF SQUARES AND SUMS OF TRIANGULAR NUMBERS
Authors: ADIGA CHANDRASHEKAR , COOPER SHAUN , HAN JUNG HUN
Published: September 2005

Let rk(n) and tk(n) denote the number of representations of n as a sum of k squares, and as a sum of k triangular numbers, respectively. We give a generalization of the result rk(8n + k) = cktk(n), which holds for 1 ≤ k ≤ 7, where ck is a constant that depends only on k. Two proofs are provided. One involves generating functions and the other is combinatorial.
A QUANTITATIVE VERSION OF BILU'S EQUIDISTRIBUTION THEOREM
Authors: PETSCHE CLAYTON
Published: September 2005

We use Fourier-analytic methods to give a new proof of Bilu's theorem on the complex equidistribution of small points on the one-dimensional algebraic torus. Our approach yields a quantitative bound on the error term in terms of the height and the degree.
A THEOREM ON SEVEN-COLORED OVERPARTITIONS AND ITS APPLICATIONS
Authors: LOVEJOY JEREMY
Published: September 2005

A q-series identity in four parameters is established and interpreted as a statement about 7-colored overpartitions. As corollaries some overpartition theorems of the Rogers–Ramanujan type and some weighted overpartition theorems are exhibited. Among these are overpartition analogues of classical partition theorems of Schur and Göllnitz.
LARGE SIEVE INEQUALITY WITH CHARACTERS FOR POWERFUL MODULI
Authors: BAIER STEPHAN , ZHAO LIANGYI
Published: September 2005

In this paper we aim to generalize the results in [1, 2, 19] and develop a general formula for large sieve with characters to powerful moduli that will be an improvement to the result in [19].
The Current Status of Thalidomide in the Management of Multiple Myeloma
Authors: Glasmacher Axel , von Lilienfeld-Toal Marie
Published: September 2005

Early anticancer research involving thalidomide was abandoned in the 1960s as the catastrophe surrounding the drug emerged, but research efforts were picked up in the 1990s when thalidomide’s antiangiogenic and anti-tumour necrosis factor properties were explored. More than 50,000 patients with multiple myeloma are estimated to have been treated with thalidomide to date. Research with thalidomide provides clear and convincing evidence that thalidomide monotherapy is efficacious in relapsed and refractory patients with multiple myeloma. Results typically show a consistent 30% (95% confidence interval 27–32%) response rate (partial response + complete response, defined as a reduction of at least 50% in the monoclonal protein). Thalidomide treatment compares favourably with other typical treatments for multiple myeloma. In seven trials that included 332 patients, vincristine, adriamycin and dexamethasone (VAD) had a response rate of 39% (32–45%), while a trial in 193 patients showed a response rate with bortezomib of 27% (21–34%). The use of thalidomide in combination therapy could boost its efficacy further. More studies to look at the toxicity of the drug need to be carried out. Despite thalidomide’s dark past, this drug is of major interest and could be brought back to clinical use in a controlled manner.
Pharmacological Investigation of Trimetazidine in Models of Inflammation, Pain and Gastric Injury in Rodents
Authors: Abdel-Salam Omar M.E. , El-Batran Siham
Published: September 2005

The antinociceptive, anti-inflammatory and gastric effects of trimetazidine (2,3,4-trimethoxybenzyl-piperazine dihydrochloride), a novel anti-ischaemic compound, were evaluated in various animal models. In acute pain models, namely acetic acid-induced writhing, hot-plate assay, tail electric stimulation test, capsaicin-induced pain and the formalin test, trimetazidine (1.8–7.2 mg/kg, i.p.) showed marked antinociceptive effects. Trimetazidine did not produce any behavioural impairment as revealed by the mouse rotarod. The inhibition of writhing response by trimetazidine was reduced by yohimbine, theophylline (and to a certain extent by sulpiride) but not by prazosin, guanethidine, naloxone, atropine, propranolol, haloperidol, domperidone, clozapine, glibenclamide or caffeine. The carrageenan-evoked acute paw oedema was reduced by 19.2–21.2 and 17–18.6% by 3.6 and 7.2 mg/kg trimetazidine, respectively. The drug did not alter the oedema-suppressive effect of indomethacin or dexamethasone, but reduced that of rofecoxib. Trimetazidine at 7.2 mg/kg reduced immobility time in Porsolt’s forced-swimming test by 28.9%. The acute gastric mucosal lesions evoked by indomethacin in the rat were inhibited in a dose-dependent manner by co-administration of trimetazidine. In anesthetized rats, trimetazidine potentiated the gastric acid secretory response. This study indicates that trimetazidine possesses antinociceptive and gastric protective properties. The antinociceptive properties of trimetazidine are likely to be centrally mediated, but do not involve opioid pathways.
Plasma Exchange Using a Continuous Venovenous Hemofiltration Machine in Children
Authors: Ciechanska Ewa , Segal Lauren , Wong Hubert , Chretien Christine , Feber Janusz , Filler Guido
Published: September 2005

Background: There is considerable interest in using continuous venovenous hemofiltration machines for plasma exchange therapy in children. Methods: Retrospective study of 7 patients and 61 plasma exchange treatments using the Baxter/Edwards Lifesciences BM25 machine with commercially available plasma filters (mostly Asahi Plasmaflo). Results: The average total exchange volume was 1.5 times the plasma volume, achieved at a blood flow rate of 100 ml/m2 (3.5 ml/kg/min) and a turnover rate of 25 ml/kg/h over a 3-hour duration. Fifty-six percent of the time, a mean heparin bolus of 29 units/kg resulted in subtherapeutic activated clotting times. Mean heparin infusion rates of 35 units of heparin/kg/h achieved effective anticoagulation. A calcium infusion rate of 0.11 ± 0.05 mmol/kg/h avoided hypocalcemia. One patient experienced the serious complication of membrane reaction. Conclusions: This setup provides a safe approach to plasma exchange in children. A similar method could be implemented in other centers.
Unusual Complication of Central Venous Catheter in Hemodialysis
Authors: Di Iorio Biagio R. , Mondillo Fiorentino , Bortone Sara , Nargi Paola , Capozzi Michele , Spagnuolo Tommaso , Cucciniello Emanuele , Bellizzi Vincenzo
Published: September 2005

A case of a partial rupture of a cuffed central venous catheter (CVC) implanted in the femoral vein with the purpose of being used for chronic hemodialysis is described in a 74-year-old female patient. Of relevance is that the CVC described was from the same manufacturer as the previous one that had lasted 12 years.
Comparison of Lamellar Body Counts Using Light Microscopy with Standard Coulter Counter Techniques to Assess Fetal Lung Maturity
Authors: Hunter Laura A. , McKenna David S. , Baptista Matt A.
Published: September 2005

Objective: To determine if lamellar body counts determined using light microscopy and a manual hemochromocytometer correlate with counts made on standard electronic cell counters. Methods: Aliquots of amniotic fluid samples obtained by amniocentesis to assess fetal lung maturity were divided into two sterile tubes. One tube was sent immediately to be counted in a cell counter by standard technique and the other tube was stored at –70°C until manual counting could be performed. Manual counts on the same samples were made on two different occasions. Intra-observer variability and correlation with the standard technique was determined. Pearson coefficient was calculated. Results: There were 11 specimen pairs. The intra-observer correlation was significant: intraclass correlation coefficient 0.95 (CI 0.84–0.99). There was significant correlation between the Coulter counter lamellar body counts and manual counts: intraclass correlation coefficients 0.88 (CI 0.62–0.97) and 0.92 (CI 0.73–0.98), respectively. Conclusion: Lamellar body counts determined by light microscopy correlate well with results obtained for lamellar body counts using standard Coulter counter techniques. Results of this pilot study show that this experimental method of evaluating fetal lung maturity deserves further evaluation.
Validating the DemTect with 18-Fluoro-2-Deoxy-Glucose Positron Emission Tomography as a Sensitive Neuropsychological Screening Test for Early Alzheimer Disease in Patients of a Memory Clinic
Authors: Scheurich Armin , Müller Matthias J. , Siessmeier Thomas , Bartenstein Peter , Schmidt Lutz G. , Fellgiebel Andreas
Published: September 2005

Objectives: The first study to validate the diagnostic value of the DemTect, a short neuropsychological screening test for dementia (8–10 min), using 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in patients of a memory clinic. Methods: DemTect results were compared to the clinical diagnosis and to FDG-PET as a reference method for the early in vivo detection of Alzheimer’s disease (AD). Results: 38 patients (age 65.2 ± 9.8 years, 16 men, 22 women) were investigated using clinical standard examination, FDG-PET, and cranial magnetic resonance imaging. According to NINCDS-ADRDA and Petersen’s criteria, 18 patients had dementia of the Alzheimer type (DAT) and 13 patients received the diagnosis of mild cognitive impairment (MCI). Compared to the clinical diagnosis, a DemTect cutoff score of ≤11 points demonstrated good sensitivity (83.3%) and specificity (70.0%) for the detection of DAT, whereas the best cutoff score for MCI was ≤13 points with comparable sensitivity (84.6%) and specificity (85.7%). With regard to FDG-PET, the DemTect demonstrated excellent sensitivity (93%) and low specificity (50%) for the detection of AD-typical patterns of cerebral glucose metabolism (cutoff ≤13 points). Conclusion: DemTect is a favorable neuropsychological screening instrument for detecting cognitive dysfunction even in predementia stages of AD. For definite cross-sectional diagnosis, further diagnostic evaluation with higher specificity, e.g. comprehensive neuropsychological examination, FDG-PET or other biomarkers, is necessary.
Grepafloxacin Concentration in Ocular Tissues after Intravenous Infusion in Rabbits with Intraocular Inflammation
Authors: Pérez-Oliván S. , Pinilla I. , Bregante M.A. , Solans C. , Ruiz Moreno O. , Garcia M.A. , Honrubia F.M.
Published: September 2005

Purpose: To determine the penetration of grepafloxacin into ocular tissues during experimental ocular inflammation. Methods: 10 albino and 10 pigmented rabbits underwent a continuous intravenous infusion of the drug 24 h after injecting Salmonella typhimurium toxin intravitreously, creating ocular inflammation. The animals were killed and grepafloxacin levels were determined in plasma and ocular tissues using high performance liquid chromatography. Results: Grepafloxacin levels achieved a steady-state plasma concentration of 1.5 µg/ml. The drug diffused more towards vascularized tissues (chorioretina and iris) in both albino and pigmented rabbits with a tissue/serum ratio higher than 1. Grepafloxacin showed more affinity to pigmented tissue, rising levels of 40,000–50,000 ng/g in the chorioretina and iris in pigmented animals. After inflammation, grepafloxacin intraocular penetration increased in albino animals with levels exceeding the minimum inhibitory concentration for the most common ocular pathogens. Conclusion: Grepafloxacin intraocular penetration is higher in pigmented tissues. Ocular inflammation increases the drug penetration into the vitreous.
Pigment-Epithelium-Derived Factor Is Upregulated in Photocoagulated Human Retinal Pigment Epithelial Cells
Authors: Hattenbach Lars-Olof , Beck Karl-Friedrich , Pfeilschifter Josef , Koch Frank , Ohrloff Christian , Schacke Wolfgang
Published: September 2005

There is much evidence that pigment-epithelium-derived factor (PEDF) is a potent antiangiogenic cytokine which inhibits retinal and choroidal neovascularization by inducing apoptosis in activated vascular endothelial cells. Furthermore, the regulation of PEDF appears to be linked to the regulation of vascular endothelial growth factor (VEGF), one of the most potent inducers of intraocular neovascularization. Previous studies have established that thermal photocoagulation, the mainstay in the therapy of various neovascular diseases of the posterior segment, results in a decrease in intraocular concentrations of VEGF and other angiogenic growth factors, thereby inhibiting active retinal neovascularization. In the current study, we sought to determine whether thermal photocoagulation has the potential to regulate the expression of PEDF in human retinal pigment epithelial (RPE) cells. Cultures of RPE cells were photocoagulated with a 532-nm diode laser. Subsequently, RNA was isolated for RT-PCR, and whole-cell extracts and precipitated cell culture supernatant were subjected to Western blot analysis. According to our results, PEDF mRNA and protein are significantly upregulated after photocoagulation. Moreover, PEDF protein was found to be secreted in the cell culture medium.
Applying an Artificial Neural Network to Predict Total Body Water in Hemodialysis Patients
Authors: Chiu Jainn-Shiun , Chong Chee-Fah , Lin Yuh-Feng , Wu Chia-Chao , Wang Yuh-Feng , Li Yu-Chuan
Published: September 2005

Background: Estimating total body water (TBW) is crucial in determining dry weight and dialytic dose for hemodialysis patients. Several anthropometric equations have been used to predict TBW, but a more accurate method is needed. We developed an artificial neural network (ANN) to predict TBW in hemodialysis patients. Methods: Demographic data, anthropometric measurements, and multifrequency bioelectrical impedance analysis (MF-BIA) were investigated in 54 patients. TBW measured by MF-BIA (TBW-BIA) was the reference. The predictive value of TBW based on ANN and five anthropometric equations (58% of actual body weight, Watson formula, Hume formula, Chertow formula, and Lee formula) was evaluated. Results: Predictive TBW values derived from anthropometric equations were significantly higher than TBW-BIA (31.341 ± 6.033 liters). The only non-significant difference was between TBW-ANN (31.468 ± 5.301 liters) and TBW-BIA (p = 0.639). ANN had the strongest Pearson’s correlation coefficient (0.911) and smallest root mean square error (2.480); its peak centered most closely to zero with the shortest tails in an empirical cumulative distribution plot when compared with the other five equations. Conclusion: ANN could surpass traditional anthropometric equations and serve as a feasible alternative method of TBW estimation for chronic hemodialysis patients.
Inhibition of Rho-Kinase by Hydroxyfasudil Prevents Vasopressin-Induced Myocardial Ischemia in Donryu Rats by Attenuating Coronary Vasoconstriction
Authors: Vincelette Jon , Pagila Rene , Kawai Kohichi , Ishii Masaaki , Horimizu Yuko , Vergona Ronald , Sullivan Mark E. , Morser John , Dole William P. , Wang Yi-Xin
Published: September 2005

Background: Inhibition of rho-kinase has been shown to attenuate vasopressin (AVP)-induced myocardial ischemia measured as S-wave depression in Donryu rats. This has been attributed to a direct inhibitory effect on AVP-induced coronary vasoconstriction. However, since AVP also increased mean arterial blood pressure (MAP) which was attenuated by the rho-kinase inhibitors used, the prevention of myocardial ischemia could have been due to effects on afterload. Results: The purpose of this study was to determine if rho-kinase inhibition prevents S-wave depression independent of the effects on blood pressure. In anesthetized Donryu rats (200–340 g), infusion of AVP (0.1 IU/kg) resulted in a sustained increase in MAP (ΔMAP = 46 ± 7 mm Hg) and a transient S-wave depression (–90 ± 20 µV). Infusion of phenylephrine titrated to achieve a comparable pressor response (ΔMAP = 52 ± 2 mm Hg) resulted in a significantly smaller S-wave depression (–30 ± 20 µV). Pretreatment with the rho-kinase inhibitor, hydroxyfasudil (3 mg/kg), decreased MAP by –28 ± 2 mm Hg and significantly attenuated AVP-induced S-wave depression (–10 ± 10 µV) compared to AVP. When rats were pretreated with phenylephrine titrated to maintain MAP, hydroxyfasudil still significantly attenuated AVP-induced S-wave depression (–14 ± 12 µV). Hydralazine (1 mg/kg), which lowered MAP by –36 ± 5 mm Hg, had no significant effect on AVP-induced S-wave depression (–105 ± 32 µV). Conclusion:These data indicate that inhibition of rho-kinase with hydroxyfasudil attenuates AVP-induced myocardial ischemia independent of changes in MAP and are consistent with an inhibitory effect on coronary vasoconstriction.
Brain Hemodynamic Effects of Doxapram in Preterm Infants
Authors: Dani Carlo , Bertini Giovanna , Pezzati Marco , Pratesi Simone , Filippi Luca , Tronchin Michele , Rubaltelli Firmino F.
Published: September 2005

Background: Doxapram is a respiratory stimulant widely used for the treatment of idiopathic apnea of prematurity, although it has been demonstrated that it can induce a transient decrease of cerebral blood flow and that isolated mental delay in infants weighing <1,250 g is associated with the total dosage and duration of doxapram therapy. Objectives: To evaluate the effects of doxapram on cerebral hemodynamics in preterm infants using cerebral Doppler ultrasonography and near-infrared spectroscopy. Methods: Preterm infants who required treatment with doxapram for apnea of prematurity unresponsive to caffeine were treated with doxapram at an hourly dose of 0.5 mg·kg–1·h–1, followed by 1.5 and 2.5 mg·kg–1·h–1. Results: 20 preterm infants were studied. Doxapram induced a significant decrease of oxygenated hemoglobin (O2Hb) and cerebral intravascular oxygenation (HbD = O2Hb – HHb) and an increase of HHb and CtOx concentrations, while cerebral blood volume and cerebral blood flow velocity did not change. Conclusions: Doxapram infusion induces the increase of cerebral oxygen consumption and requirement and the contemporary decrease of oxygen delivery probably mediated by a decrease of cerebral blood flow. Caution must be recommended in prescribing this drug for apnea of prematurity.
Altered Dynamics of Action Potential Restitution and Alternans in Humans With Structural Heart Disease
Authors: Koller Marcus L. , Maier Sebastian K.G. , Gelzer Anna R. , Bauer Wolfgang R. , Meesmann M. , Gilmour Robert F.
Published: September 2005

Background—

Restitution kinetics and alternans of ventricular action potential duration (APD) have been shown to be important determinants of cardiac electrical stability. In this study, we tested the hypothesis that APD restitution and alternans properties differ between normal and diseased human ventricular myocardium.

Methods and Results—

Monophasic action potentials were recorded from the right ventricular septum in 24 patients with structural heart disease (SHD) and in 12 patients without SHD. Standard and dynamic restitution relations were constructed by plotting APD as a function of the preceding diastolic interval. The dynamic restitution relation of both groups showed a steeply sloped segment at short diastolic intervals that was associated with the occurrence of APD alternans. Patients with SHD had a wider diastolic interval range over which APD alternans was present (mean±SEM 68±11 versus 12±2 ms) and showed an earlier onset (168±7 versus 225±4 bpm) and an increased magnitude (20±2 versus 11±2 ms) of APD alternans compared with patients without SHD. The occurrence of APD alternans during induced ventricular tachycardia (6 episodes) and during rapid pacing could be derived from the dynamic restitution function.

Conclusions—

There are marked differences in the dynamics of APD restitution and alternans in the ventricular myocardium of patients with SHD compared with patients without SHD. These differences may contribute importantly to cardiac electrical instability in diseased human hearts and may represent a promising target for antiarrhythmic substrate modification.
Soft Balancing against the United States
Authors: Pape Robert A.
Published: September 2005

The George W. Bush administration's national security strategy, which asserts that the United States has the right to attack and conquer sovereign countries that pose no observable threat, and to do so without international support, is one of the most aggressively unilateral U.S. postures ever taken. Recent international relations scholarship has wrongly promoted the view that the United States, as the leader of a unipolar system, can pursue such a policy without fear of serious opposition. The most consequential effect of the Bush strategy will be a fundamental transformation in how major states perceive the United States and how they react to future uses of U.S. power. Major powers are already engaging in the early stages of balancing behavior against the United States, by adopting “soft-balancing” measures that do not directly challenge U.S. military preponderance but use international institutions, economic statecraft, and diplomatic arrangements to delay, frustrate, and undermine U.S. policies. If the Bush administration continues to pursue aggressive unilateral military policies, increased soft balancing could establish the basis for hard balancing against the United States. To avoid this outcome, the United States should renounce the systematic use of preventive war, as well as other aggressive unilateral military policies, and return to its traditional policy governing the use of force-a case-by-case calculation of costs and benefits.
Foreign Bodies at Work: Good, Docile and Other-ed
Authors: Abdullah Noorman
Published: September 2005

The lived, and oftentimes silenced, experiences of "foreign workers" articulate the negotiation of power relations between "citizen" and "foreigner", and "Us" and "Them". These are translated into discursive practices that, in effect, legitimize and entrench differences — hence, inequalities — that effectively discipline the "foreign worker" as "not one of Us". By taking the example of Bangladeshi construction workers in Singapore as a case study, I argue in this paper that the workspaces of "foreign construction workers" in Singapore typify that of a "total institution", which correspondingly moulds the worker into a discursive ideal — the "good, docile Other". Such impositions and productions of Otherness, however, face rupture as workers (re)negotiate, (re)work, and (re)inscribe their everyday lives through the employment of what James Scott (1985, 1987) terms "everyday 'resistances'" in rising above that which subjugates them. I will present in this paper primary data elicited and collated from direct participant observation, fieldwork, and in-depth interviews conducted in a construction project in Singapore.
Acculturative Stress and Identity Crisis: South Asians in Canadian Academe
Authors: Samuel Edith
Published: September 2005

This article explores the psychological processes of acculturative stress and identity crises in the lives of South Asian students in academe. It is evident that the anxieties about South Asian students' cultural adaptabilities are sites of contested meanings. This inquiry unsettles the seemingly predetermined category of "South Asian student" and considers how South Asian students' experiences are couched in a series of disparaging discourses. The conflicts and contradictions between the "traditional" culture "back home" and "Canadian" culture are noticeable. Further, the binaries of "tradition"/"modern"; "Indianized"/"Canadianized"; "Third World"/"West"; and "advanced"/"backward" are perceived to be divergent groupings. These contrasting categories are viewed as "mutually exclusive so that the only logical conclusion to anyone struggling with culture conflict is to choose either one side or the other, primarily for the sake of mental and emotional well-being (Paur, 1994:25)."
Deleuze/Derrida: Towards an Almost Imperceptible Difference
Authors: Kuiken Kir
Published: September 2005

This paper approaches the problem of the relation between Deleuze and Derrida by focusing on their respective readings of Heidegger's interpretation of Nietzsche's eternal return. It argues that the difference between Deleuze and Derrida cannot be measured in terms of their explicit statements about Heidegger, but in terms of how they relate their own readings of Nietzsche to Heidegger's positioning of him as the last metaphysician. The paper focuses on Deleuze's brief analyses of Heidegger in Difference and Repetition and Derrida's numerous references to the eternal return throughout his oeuvre, particularly in the essay Différance. I argue that Deleuze and Derrida articulate two different relations to the simulacrum through the way in which they position their own work in relation to Heidegger's understanding of Nietzsche.
Elemental Translations: From Friedrich Nietzsche and Luce Irigaray
Authors: Baracchi Claudia
Published: September 2005

This essay considers the tensions informing Nietzsche's reflection on intertwined issues of nature, art, sexuality, and the feminine. Through the figure of Dionysus, Nietzsche articulates a suggestive understanding of generation as the upsurge of nature in its transformative movement. The juxtaposition of Luce Irigaray's elaboration of the Dionysian calls for an interrogation of Nietzsche's work regarding (1) the sublimation of nature into art and of sexuality or sensuality into artistic drives, (2) the oblivion of sexual difference in the coupling of Apollo and Dionysus, and (3) the disappearance of love from the scene of creativity and procreation and, concomitantly, the emphasis on suffering and dismemberment.
Ontology, Transcendence, and Immanence in Emmanuel Levinas' Philosophy
Authors: Bergo Bettina
Published: September 2005

This essay studies the unfolding of Levinas' concept of transcendence from 1935 to his 1984 talk entitled "Transcendence and Intelligibility." I discuss how Levinas frames transcendence in light of enjoyment, shame, and nausea in his youthful project of a counter-ontology to Heidegger's Being and Time. In Levinas' essay, transcendence is the human urge to get out of being. I show the ways in which Levinas' early ontology is conditioned by historical circumstances, but I argue that its primary aim is formal and phenomenological; it adumbrates formal structures of human existence. Levinas' 1940s ontology accentuates the dualism in being, between what amount to a light and a dark principle. This shift in emphasis ushers in a new focus for transcendence, which is now both sensuous and temporal, thanks to the promise of fecundity. Totality and Infinity (1961) pursues a similar onto-logic, while shifting the locus of transcendence to a non-sexuate other. The final great work, Otherwise than Being or beyond Essence (1974) offers a hermeneutic phenomenology of transcendence-in-immanence. It rethinks Husserl's focus on the transcendence of intentionality and its condition of possibility in the passive synthesis of complex temporality. If the 1974 strategy 'burrows beneath' the classical phenomenological syntheses, it also incorporates unsuspected influences from French psychology and phenomenology. This allows Levinas to develop a philosophical conception of transcendence that is neither Husserl's intentionality nor Heidegger's temporal ecstases, in what amounts to an original contribution to a phenomenology both hermeneutic and descriptive.