Woodwind tonehole's linear behavior is characterized by two complex quantities: the series and shunt acoustic impedances. A method to determine experimentally these two quantities is presented for the case of open toneholes. It is based on two input impedance measurements. The method can be applied to clarinet-like instruments, and can be used for undercut toneholes as well as toneholes with pads above their output, under the condition that a symmetry axis exists. The robustness of the method proposed is explored numerically through the simulation of the experiment when considering geometrical and measurement uncertainties. Experimental results confirm the relevance of the method proposed to estimate the shunt impedance. Even the effect of small changes in the hole's geometry, such as those induced by undercutting, are characterized experimentally. The main effect of undercutting is shown to be a decrease in the tonehole's acoustic mass, in agreement with theoretical considerations based on the shape of the tonehole. Investigation on the effects of pads will be studied in a further work. Experimental results also reveal that losses in toneholes are significantly higher than those predicted by the theory. Therefore, the method is suitable for the experimental determination of the shunt impedance, but it is not convenient for the characterization of the series impedance.

A saxophone mouthpiece fitted with sensors is used to observe the oscillation of a saxophone reed, as well as the internal acoustic pressure, allowing to identify qualitatively different oscillating regimes. In addition to the standard two-step regime, where the reed channel successively opens and closes once during an oscillation cycle, the experimental results show regimes featuring two closures of the reed channel per cycle, as well as inverted regimes, where the reed closure episode is longer than the open episode. These regimes are well-known on bowed string instruments and some were already described on the Uilleann pipes. A simple saxophone model using measured input impedance is studied with the harmonic balance method, and is shown to reproduce the same two-step regimes. The experiment shows qualitative agreement with the simulation: in both cases, the various regimes appear in the same order as the blowing pressure is increased. Similar results are obtained with other values of the reed opening control parameter, as well as another fingering.

Spectra of musical instruments exhibit formants or anti-formants which are important characteristics of the sounds produced. In the present paper, it is shown that anti-formants exist in the spectrum of the mouthpiece pressure of saxophones. Their frequencies are not far but slightly higher than the natural frequencies of the truncated part of the cone. To determine these frequencies, a first step is the numerical determination of the playing frequency by using a simple oscillation model. An analytical analysis exhibits the role of the inharmonicity due to the cone truncation and the mouthpiece. A second step is the study of the input impedance values at the harmonics of the playing frequency. As a result, the consideration of the playing frequency for each note explains why the anti-formants are wider than those resulting from a Helmholtz motion observed for a bowed string. Finally numerical results for the mouthpiece spectrum are compared to experiments for three saxophones (soprano, alto and baritone). It is shown that when scaled by the length of the missing cone, the anti-formant frequencies in the mouthpiece are very similar for the three instruments. The frequencies given by the model are close to the natural frequencies of the missing cone length, but slightly higher. Finally, the numerical computation shows that anti-formants and formants might be found in the radiated pressure.

The interaction of squalamine (SQ) with eukaryotic and prokaryotic membranes was studied and compared with the interaction of two other cationic amphipathic antimicrobials (CAAs), i.e. the antibiotic polymyxin B (PMB) and the detergent hexadecyltrimethylammonium bromide (CTAB). Whole cell experiments showed that the three CAA have in common the ability to interact with lipopolysaccharide-containing membranes through a divalent cation sensitive process. Differences were found regarding their kinetics of membrane permeabilisation and their selectivity for bacteria, with a preferential permeabilisation of bacteria by PMB > SQ and no selectivity for CTAB. Experiments with lipid monolayers and bilayers showed that this selectivity did not correlate with a preferential interaction of the CAAs with lipids but rather relies on differences in their ability to penetrate lipid bilayers and to cause electrically active lesions. Incidentally, our results also suggest that the distribution coefficient of CAAs could be used to predict their selectivity for bacteria.

Background Anandamide is a lipid neurotransmitter which belongs to a class of molecules termed the endocannabinoids involved in multiple physiological functions. Anandamide is readily taken up into cells, but there is considerable controversy as to the nature of this transport process (passive diffusion through the lipid bilayer vs. involvement of putative proteic transporters). This issue is of major importance since anandamide transport through the plasma membrane is crucial for its biological activity and intracellular degradation. The aim of the present study was to evaluate the involvement of cholesterol in membrane uptake and transport of anandamide. Methodology/Principal Findings Molecular modeling simulations suggested that anandamide can adopt a shape that is remarkably complementary to cholesterol. Physicochemical studies showed that in the nanomolar concentration range, anandamide strongly interacted with cholesterol monolayers at the air-water interface. The specificity of this interaction was assessed by: i) the lack of activity of structurally related unsaturated fatty acids (oleic acid and arachidonic acid at 50 nM) on cholesterol monolayers, and ii) the weak insertion of anandamide into phosphatidylcholine or sphingomyelin monolayers. In agreement with these data, the presence of cholesterol in reconstituted planar lipid bilayers triggered the stable insertion of anandamide detected as an increase in bilayer capacitance. Kinetics transport studies showed that pure phosphatidylcholine bilayers were weakly permeable to anandamide. The incorporation of cholesterol in phosphatidylcholine bilayers dose-dependently stimulated the translocation of anandamide. Conclusions/Significance Our results demonstrate that cholesterol stimulates both the insertion of anandamide into synthetic lipid monolayers and bilayers, and its transport across bilayer membranes. In this respect, we suggest that besides putative anandamide protein-transporters, cholesterol could be an important component of the anandamide transport machinery. Finally, this study provides a mechanistic explanation for the key regulatory activity played by membrane cholesterol in the responsiveness of cells to anandamide.

Laboratory experiments in underwater acoustics aim at the validation of theoretical acoustic propagation models in well controlled environments. The experimental tank of the LMA Laboratory provides an ideal environment for testing long range propagation codes. The tank is relatively long and the water depth is adjustable in order to simulate real propagation experiments in environments of variable depths. The purpose of this paper is to describe the experimental procedure for the realization of a long range propagation experiment in an experimental tank, using sources of appropriate frequency. The bottom of the tank was covered by a thick layer of fine sand with well known properties to simulate a real.stic sea-bed. It was supposed to be horizontal and perfectly flat without any ripples on the surface. The measured, monochromatic continuous wave, signals are processed to provide the acoustic field at various depths and ranges in the tank in decibels, and are compared with theoretical models based on normal-mode theory and parabolic equations. The comparison in the cases studied, which corresponded to shallow water transmissions are encouraging. Technological problems and scaling factors are also discussed.

High cervical spinal cord injury (SCI) interrupts bulbospinal respiratory pathways innervating phrenic motoneurons, and induces an inactivation of phrenic nerves (PN) and diaphragm. We have previously shown that the ipsilateral (ipsi) PN was inactivated following a lateral C2 SCI, but was spontaneously partially reactivated 7 days post-SCI. This phrenic reactivation depended on contralateral (contra) descending pathways, located laterally, that cross the spinal midline. We analysed here whether long-term post-lesional changes may occur in the respiratory network. We showed that ipsi PN reactivation was greater at 3 months compared with 7 days post-SCI, and that it was enhanced after acute contra phrenicotomy (Phx), which also induced a substantial reactivation of the ipsi diaphragm (not detected at 7 days post-SCI). At 3 months post-SCI (compared with 7 days post-SCI), ipsi PN activity was only moderately affected by ipsi Phx or by gallamine treatment, a nicotinic neuromuscular blocking agent, indicating that it was less dependent on ipsi sensory phrenic afferents. After an additional acute contra SCI (C1) performed laterally, ipsi PN activity was abolished in rats 7 days post-SCI, but persisted in rats 3 months post-SCI. This activity thus depended on new functional descending pathways located medially rather than laterally. These may not involve newly recruited neurons as retrograde labelling showed that ipsi phrenic motoneurons were innervated by a similar number of medullary respiratory neurons after a short and long post-lesional time. These results show that after a long post-lesional time, phrenic reactivation is reinforced by an anatomo-functional reorganization of spinal respiratory pathways.

The work deals with an inversion procedure for the estimation of geometrical and environmental parameters of a simulated shallow water environment. Two of the most significant parameters in a shallow water environment affecting the acoustic field in long range acoustic propagation are the sound speed of the sediment and the depth of the water column. The accurate estimation of these parameters is perhaps the most important task in scaled laboratory experiments. Therefore, the calibration phase of such an experiment involves the estimation of these parameters, preferably using acoustical techniques, regardless the final scope of the experiment. The present work describes an inversion procedure based on standard match field processing. The acoustic signal used was a short gaussian shaped pulse and it was recorded at a certain distance from the source and for several depths in the water column. The spectrum of the recorded signal was obtained using FFT and the complex acoustic field at the central frequency was calculated. The estimated values of the water depth and the sound speed in the sand which was used to simulate the sea-bed, were found in accordance with the observed modal structure of the acoustic field.

This study deals with the bearing and the range estimation for buried objects problem. We propose a new method that combines the array processing approaches with an accurate acoustical modeling for the buried objects localization problem in the underwater acoustics environment. This method incorporates the exact solution for the scattered field (instead of using the plane wave model) in the MUSIC method, uses the focusing operator to decorrelate the signals and estimates both the range and the bearing objects. Finally, the performances of the proposed method are validated on experimental data recorded during an underwater acoustics experiments.

The primary objective of the Telescope a Action Rapide pour les Objets Transitoires (TAROT - Rapid Action Telescope for Transient Objects) observatory is the detection of cosmic Gamma-Ray Burst sources at optical wavelengths while still active in Gamma-rays. It features a very rapid slewing mount, a 25 cm aperture telescope with a 2 x 2 deg. fov, and is able to reach the 17th V magnitude in 10 s. A powerful scheduling algorithm, and an automated data processing system makes TAROT a fully autonomous facility. TAROT entered into service during the fall of 1998.

TAROT-I is an automatic, autonomous ground based observatory whose primary goal is the rapid detection of the optical counterparts of cosmic gamma-ray burst sources. It will Se able to begin imaging any GRB localization seconds after receipt of an alert from CGRO/BATSE or HETE-2. TAROT-1 will reach the 17th V magnitude in 10 seconds, at a 10 sigma confidence level. TAROT will be able to observe GRB positions given by Beppo-SAX or RXTE, EUV transients from ALEXIS alerts, etc. TAROT will also study a wide range of secondary objectives and will feature a complete automatic data analysis system, and powerful scheduling software. TAROT will be installed this fall on the Plateau du Calern, 1200m above sea level. We report on the status of the project.

''Tonotechnics'' was the term which used to denote the art of driving embossed cylinders used for the manufacture of automated musical instruments. ''The art of the organ builder'' written in the 18th century by Dom Bedos de Celles describes the technique.Nowadays the term is used more widely to include the transcription of musical notes not only on cylinders but on other materials such as paper or cardboard, and more particularly on the cards used for mechanical organ music.A machine using ''tonotecnics'' designed by Robert Hopp has just been presented at the 1992 september music fair in Paris. The purpose of the machine is to produce perforated cards for mechanical organ music using a musical file (format MIDIFILE) recorded on an ordinary musical sequencer.Until now perforating the cards was a long and often hazardous task frequently subject to error. Today, thanks to this machine one can not only reproduce the authentic manner of playing with greater ease and precision but also imagine a new, wider scope for the composition of mechanical organ music.Some parts of the musical score composed by M. Michel PORTAL for the film ''l'anniversaire du poisson lune'' were only made possible by the design of this machine.Its originality lies in its capacity to reproduce the traditional sounds of the instrument and thanks to sophisticated technology to improve the quality of the cards necessary to produce such music.In the near future we hope to restore to perfect musical order mechanical organ music cards which are too old or badly damaged for use.Currently prized by collectors but impossible to exploit these cards could be scanned by means of a camera or a coupled charge device in order to transcribe their original music onto new cards.Thus the cultural wealth of mechanical organ music could be saved from oblivion.

The main aspects of the FTM (fault tolerant machine) architecture, which has been built by combining stable transactional memory boards with processors of a standard machine, are reviewed, and the design principles are presented. The FTM design is based on GOTHIC, a fault-tolerant distributed system that relies on stable storage technology. A fast stable transactional memory (STM) board, which offers built-in atomic operations on groups of small data structures with very good response time, has been integrated into a multiprocessor architecture, each processor possessing its own STM. The FTM hardware architecture has been built from standard open machine using dynamic redundancy in the building of the processing elements. The FTM prototype is presented, and the STM functions are described in detail.<>

The purpose of the Fault Tolerant Multiprocessor project (FTM) is to design a fault tolerant machine based on a Stable Transactional Memory (STM). The STM allows manipulation of stable objects within atomic transactions. The building of the operating system has led us to define a C++ interface to the STM which provides stable classes. Robust object oriented programs which resist processor failures can be written in C++ using stable objects and transactions.

Heart rate (HR) was continuously monitored during successive 24-hr periods in 19 healthy subjects and 26 major depressed patients (DSM III-R). Recordings were performed after a 2-week wash-out period and the morningness or eveningness typology of each subject was determined. The chronobiological parameters and rhythm percentage (RP) were calculated by the single cosinor method from the smoothed HR curves of each subject. In normal subjects, HR follows a circadian rhythm (RP greater than 65%) with the lowest values at night. Morning type subjects have an earlier peak time (13:30) than evening type subjects (17:30). Major depressive patients were split into two groups; in the first one HR circadian rhythm was still present (RP greater than 63%) with a decrease in amplitude (24%) while in the second group, no circadian rhythm of HR could be detected (RP less than 25%, decrease in amplitude greater than 70%). In the group of patients with a persisting HR circadian rhythm, no veritable phase advance was observed. Our results suggest that circadian HR rhythm, which can be easily studied with non-invasive methods, might represent a chronobiological marker of some depressions. Given the lag that exists between the rhythms of morning type and evening type subjects, our study also stresses the importance of taking into account this behavioural trait in chronobiological studies.

article Free Access Share on Stable transactional memories and fault tolerant architectures Authors: M. Banâtre IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile , Ph. Joubert IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile , Ch. Morin IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile , G. Muller IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile , B. Rochat IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile , P. Sanchez IRISA Campus de Beaulieu, 35042 Rennes cedex (France) IRISA Campus de Beaulieu, 35042 Rennes cedex (France)View Profile Authors Info & Claims ACM SIGOPS Operating Systems ReviewVolume 25Issue 1Jan. 1991pp 68–72https://doi.org/10.1145/122140.122148Published:02 January 1991Publication History 0citation164DownloadsMetricsTotal Citations0Total Downloads164Last 12 Months4Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF