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It is well known that many common planetary minerals exhibit prominent absorption features. Consequently, the analysis of spectral reflectance measurements has become a major tool of remote sensing. Quantifying the mineral abundances, however, is not a trivial task. The interaction between the incident light rays and particulate surfaces, e.g., the lunar regolith, leads to a non-linear relationship between the reflectance spectra of the pure minerals, the so-called “endmembers”, and the surface’s reflectance spectrum. It is, however, possible to transform the non-linear reflectance mixture into a linear mixture of single-scattering albedos of the Hapke model. The abundances obtained by inverting the linear single-scattering albedo mixture may be interpreted as volume fractions which are weighted by the endmember’s extinction coefficient. Commonly, identical extinction coefficients are assumed throughout all endmembers and the obtained volume fractions are converted to mass fractions using either measured or assumed densities. In theory, the proposed method may cover different grain sizes if each grain size range of a mineral is treated as a distinct endmember. Here, we present a method to transform the mixing coefficients to mass fractions for arbitrary combinations of extinction coefficients and densities. The required parameters are computed from reflectance measurements of well defined endmember mixtures. Consequently, additional measurements, e.g., the endmember density, are no longer required. We evaluate the method based on laboratory measurements and various results presented in the literature, respectively. It is shown that the procedure transforms the mixing coefficients to mass fractions yielding an accuracy comparable to carefully calibrated laboratory measurements without additional knowledge. For our laboratory measurements, the square root of the mean squared error is less than 4.82 wt%. In addition, the method corrects for systematic effects originating from mixtures of endmembers showing a highly varying albedo, e.g., plagioclase and pyroxene.

While the interpretation of spectral reflectance data has been widely applied to detect the presence of minerals, determining and quantifying the abundances of minerals contained by planetary surfaces is still an open problem. With this paper we address one of the two main questions arising from the spectral unmixing problem. While the mathematical mixture model has been extensively researched, considerably less work has been committed to the selection of endmembers from a possibly huge database or catalog of potential endmembers. To solve the endmember selection problem we define a new spectral similarity measure that is not purely based on the reconstruction error, i.e. the squared difference between the modeled and the measured reflectance spectrum. To select reasonable endmembers, we extend the similarity measure by adding information extracted from the spectral absorption bands. This will allow for a better separation of spectrally similar minerals. Evaluating all possible subsets of a possibly very large catalog that contain at least one endmember leads to an exponential increase in computational complexity, rendering catalogs of 20–30 endmembers impractical. To overcome this computational limitation, we propose the usage of a genetic algorithm that, while initially starting with random subsets, forms new subsets by combining the best subsets and, to some extent, does a local search around the best subsets by randomly adding a few endmembers. A Monte-Carlo simulation based on synthetic mixtures and a catalog size varying from three to eight endmembers demonstrates that the genetic algorithm is expected to require less combinations to be evaluated than an exhaustive search if the catalog comprises 10 or more endmembers. Since the genetic algorithm evaluates some combinations multiple times, we propose a simple modification and store previously evaluated endmember combinations. The resulting algorithm is shown to never require more function evaluations than a full exhaustive search and the number of required function evaluations appears to grow less than exponentially. It thus requires considerably less time than an exhaustive search because the number of function evaluations is a hardware independent measure of the computational complexity. To evaluate the spectral similarity measure, we created a spectral reflectance catalog of selected lunar analog minerals. Based on precisely prepared mixtures of two to three components, we show that the proposed spectral similarity measure selects less false endmembers from the catalog than a similarity measure that is purely based on the reconstruction error.

The detection of lunar lava flows based on local morphology highly depends on the available images. The thickness of lava flows, however, has been studied by many researchers and lunar lava flows are shown to be as thick as 200 m. Lunar lava flows are supposed to be concentrated on the northwestern lunar nearside. In this study we present elemental abundance maps, a petrological map and a digital terrain model (DTM) of a lava flow structure in northern Mare Serenitatis at (18.0° E, 32.4° N) and two possible volcanic vents at (11.2° E, 24.6° N) and (13.5° E, 37.5° N), respectively. Our abundance maps of the refractory elements Ca, Mg and our petrological map were obtained based on hyperspectral image data of the Moon Mineralogy Mapper (M3) instrument. Our DTM was constructed using GLD100 data in combination with a shape from shading based method to M3 and Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) image data. The obtained NAC-based DEM has a very high effective resolution of about 1–2 m which comes close to the resolution of the utilized NAC images without requiring intricate processing of NAC stereo image pairs. As revealed by our elemental maps and DEM, the examined lava flow structure occurs on a boundary between basalts consisting of low-Ca/high-Mg pyroxene and high-Ca/low-Mg pyroxene, respectively. The total thickness of the lava flow is about 100 m, which is a relatively large value, but according to our DEM the lava flow may also be composed of two or more layers.

The mid-wave infrared (MWIR) portion of the electromagnetic spectrum is critically important for a variety of applications such as LIDAR and chemical sensing. Concerning the latter, the MWIR is often referred to as the “molecular fingerprint” region owing to the fact that many molecules display distinctive vibrational absorptions in this region, making it useful for gas detection. To date, steering MWIR radiation typically required the use of mechanical devices such as gimbals, which are bulky, slow, power-hungry, and subject to mechanical failure. We present the first non-mechanical beam steerer capable of continuous angular tuning in the MWIR. These devices, based on refractive, electro-optic waveguides, provide angular steering in two dimensions without relying on moving parts. Previous work has demonstrated non-mechanical beam steering (NMBS) in the short-wave infrared (SWIR) and near infrared (NIR) using a waveguide in which a portion of the propagating light is evanescently coupled to a liquid crystal (LC) layer in which the refractive index is voltage-tuned. We have extended this NMBS technology into the MWIR by employing chalcogenide glass waveguides and LC materials that exhibit high MWIR transparency. As a result, we have observed continuous, 2D MWIR steering for the first time with a magnitude of 2.74° in-plane and 0.3° out-of-plane.

Laser communications systems provide numerous advantages for establishing satellite-to-ground data links. As a carrier for information, lasers are characterized by high bandwidth and directionality, allowing for fast and secure transfer of data. These systems are also highly resistant to RF influences since they operate in the infrared portion of the electromagnetic spectrum, far from radio bands. In this paper we will discuss an entirely non-mechanical electro-optic (EO) laser beam steering technology, with no moving parts , which we have used to form robust 400 Mbps optical data connections through air. This technology will enable low cost, compact, and rugged free space optical (FSO) communication modules for small satellite applications. The EO beam-steerer at the heart of this system is used to maintain beam pointing as the satellite orbits. It is characterized by extremely low values for size, weight and power consumption (SWaP) – approximately 300 cm 3 , 300 g, and 5 W respectively, which represents a marked improvement compared to heavy, and power-consuming gimbal mechanisms. It is capable of steering a 500 mW, 1 mm short wave infrared (SWIR) beam over a field of view (FOV) of up to 50° x 15°, a range which can be increased by adding polarization gratings, which provide a coarse adjust stage at the EO beam scanner output. We have integrated this device into a communication system and demonstrated the capability to lock on and transmit a high quality data stream by modulation of SWIR power.

There is currently a good deal of interest in developing laser radar (ladar) for autonomous navigation and collision avoidance in a wide variety of vehicles. In many of these applications, minimizing size, weight and power (SWaP) is of critical importance, particularly onboard aircraft and spacecraft where advanced imaging systems are also needed for location, alignment, and docking. In this paper, we describe the miniaturization of a powerful ladar system based on an electro-optic (EO) beamsteering device in which liquid crystal birefringence is exploited to achieve a 20° x 5° field of view (FOV) with no moving parts. This FOV will be significantly increased in future versions. In addition to scanning, the device is capable of operating in a “point and hold” mode where it locks onto a single moving object. The nonmechanical design leads to exceptionally favorable size and weight values: 1 L and < 1 kg respectively. Furthermore, these EO scanners operate without mechanical resonances or inertial effects. A demonstration was performed with a 50 kHz, 1 microjoule laser with a 2 mm beam diameter to image at a range of 100 m yielding a 2 fps frame rate limited by the pulse laser repetition rate. The fine control provided by the EO steerer results in an angle precision of 6x10-4 degrees. This FOV can be increased with discreet, non-mechanical polarization grating beamsteerers. In this paper, we will present the design, preliminary results, and planned next generation improvements.

Background: A 65-year-old woman was admitted to the emergency department for sudden onset of neck pain and dysesthesia of both upper limbs. The pain occurred spontaneously, without any history of recent trauma. Rapidly after her admission, she developed tetraparesia. The patient had a past medical history of long standing hypertension correctly controlled as confirmed at admission. Neurological examination confirmed the tetraparetic status with a sensory level at Th3. Moreover, a saddle anesthesia with impaired bladder control was observed. Cranial nerve examination and consciousness of the patient remained normal. Laboratory coagulation tests and platelets count were all within normal limits.

We will describe the construction and performance of a prototype high speed, non-mechanically scanned, laser system that is coupled to a custom planar waveguide optical amplifier. The system provides high speed (10 kHz) scanning of

We present new photonic-true-time-delay (PTTD) devices, which are a key component for phased array antenna (PAA) and phased array radar (PAR) systems. These new devices, which are highly manufacturable, provide the previously unattainable combination of large time delay tunability and low insertion loss , in a form factor that enables integration of many channels in a compact package with very modest power consumption. The low size, weight, and power are especially advantageous for satellite deployment. These devices are enabled by: i) “Optical Path Reflectors” or OPRs that compresses a >20 foot change in optical path length, i.e ., a >20 nsec tuning of delay, into a very compact package (only centimeters), and ii) electro-optic angl e actuators that can be used to voltage tune or voltage select the optical time delay. We have designed and built OPRs that demonstrated: large time delay tunability (>30 nsecs), high RF bandwidth (>40 GHz and likely much higher), high resolution (

In this paper we present new electro-optic beam steering technology and propose to combine it with optical telecommunication technology, thereby enabling low cost, compact, and rugged free space optical (FSO) communication modules for small-sat applications. Small satellite applications, particularly those characterized as “micro-sats” are often highly constrained by their ability to provide high bandwidth science data to the ground. This will often limit the relevance of even highly capable payloads due to the lack of data availability. FSO modules with unprecedented cost and size, weight, and power (SWaP) advantages will enable multi-access FSO networks to spread across previously inaccessible platforms. An example system would fit within a few cubic inch volume, require less than 1 watt of power and be able to provide ground station tracking (including orbital motion over wide angles and jitter correction) with a 50 to 100 Mbps downlink and no moving parts. This is possible, for the first time, because of emergent and unprecedented electro-optic (EO) laser scanners which will replace expensive, heavy, and power-consuming gimbal mechanisms. In this paper we will describe the design, construction, and performance of these new scanners. Specific examples to be discussed include an all electro-optic beamsteer with a 60 degree by 40 degree field of view. We will also present designs for a cube-sat to ground flight demonstration. This development would provide a significant enhancement in capabilities for future NASA and other Government and industry space projects.

Introduction et but de l’etude Limiter la sedentarite ou augmenter le niveau d’activite physique sont des objectifs therapeutiques proposes aux patients obeses severes. L’activite physique « inclut tous les mouvements effectues dans la vie quotidienne et ne se reduit pas a la seule pratique sportive ». C’est la raison pour laquelle, aujourd’hui, le professeur d’activite physique adaptee (APA) fait partie integrante des equipes multidisciplinaires dediees a la prise en charge de l’obesite severe. Neanmoins, peu de resultats sont disponibles concernant les retombees de ces prises en charge specifiques. Objectif Evaluer l’effet de l’accompagnement personnalise d’un professeur d’APA sur le niveau d’activite physique de patients obeses severes dans une unite ambulatoire specialisee. Patients et methodes Quarante-cinq patients ont ete inclus dans cette etude. Les donnees ont pu etre analysees pour 38 d’entre eux (34 femmes, âge moyen : 47,4 ans, IMC moyen : 42,4). Les patients ont beneficies d’un accompagnement personnalise incluant un bilan educatif partage et des seances de reconditionnement physique sur ergocycle. Une synthese realisee lors de l’entretien final avait pour objectif d’inciter au maintien de la pratique de l’activite physique a la suite de la prise en charge. Une enquete telephonique (questionnaire auto-construit) a ete menee a distance de l’accompagnement, 15 mois en moyenne apres la derniere seance (min : 6,7 mois ; max : 23 mois). Resultats et analyse statistique Sur les 38 patients, 30 (79 %) declarent avoir maintenu une activite physique a la suite de leur prise en charge, 24 d’entre eux (63 %) declarent poursuivre la pratique d’une activite physique au moment de l’enquete. Parmi ces derniers, 13/24 (54 %) pratiquent de facon encadree en club ou en association, 12/24 (50 %) rapportent pratiquer une activite physique autonome, et 11/24 (45 %) affirment etre plus actifs au quotidien. Les principaux leviers rapportes par les patients « devenus actifs » sont les suivants : – l’accompagnement concret et personnalise qui leur a permis de decouvrir des activites adaptees (36 %) ; – le plaisir de pratiquer une activite physique (36 %) ; – l’aide a l’orientation vers une structure de ville (27 %). Conclusion L’acces a la pratique concrete d’une activite physique, accompagnee par un professeur d’APA, semble etre un moyen d’aider les patients obeses severes inactifs a augmenter leur niveau d’activite physique. Ces resultats preliminaires meriteraient d’etre confirmes par une etude prospective de plus grande envergure.

Jet Propulsion Lab and Vescent Photonics Inc. and are jointly developing an innovative ultra-compact (volume < 10 cm 3 ), ultra-low power (

Seit etwa 15 Monaten wird an der Phoniatrischen Ambulanz der Universitat Ulm eine auf 5 Jahre angelegte multifaktorielle Langsschnittstudie uber Stottern bei Vorschulkindern durchgefuhrt. Hauptanliegen der Studie ist die Erfassung moglicher Verlaufsvariablen bei Vorschulkindern, also die Bestimmung valider Indikatoren fur mogliche Remission bzw. Chronizitat des kindlichen Stotterns. Ausserdem soUen die Forschungsdaten Aufschluss uber Differenzierungsmoglichkeiten normaler Entwicklungsunflussigkeiten von chronischem Stottern geben. Es werden Zwischenergebnisse hinsichtlich einiger Variablen mitgeteilt und diskutiert.

An emergent electro-optic technology platform, liquid crystal (LC) waveguides, will be presented with a focus on performance attributes that may be relevant to coded aperture approaches. As a low cost and low SWaP alternative to more traditional approaches (e.g. galvos, MEMs, traditional EO techniques, etc.), LC-Waveguides provide a new technique for switching, phase shifting, steering, focusing, and generally controlling light. LC-waveguides provide tremendous continuous voltage control over optical phase delays (> 2mm demonstrated), with very low loss (< 0.5 dB/cm) and rapid response time. The electro-evanescent architecture exploits the tremendous electro-optic response of liquid crystals (can be > one million pm/Volts) while circumventing their historic limitations; speeds can be in the microseconds and LC scattering losses can be reduced by orders of magnitude from conventional LC optics. This enables a new class of photonic devices: very wide analog non-mechanical beamsteerers (270° demonstrated), chip-scale widely tunable lasers (50 nm demonstrated), chip-scale Fourier transform spectrometers (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses (fl tuning from 5 mm to infinity demonstrated), ultra-low power (< 5 microWatts) optical switches, true optical time delay devices (12 nsecs demonstrated) for phased array antennas, and many more. Both the limitations and the opportunity provided by this technology for use in coded aperture schemes will be discussed.

Jet Propulsion Lab and Vescent Photonics Inc. and are jointly developing an innovative ultracompact (volume 3 ), ultra-low power ( -3 Watt-hours per measurement and zero power consumption when not measuring), completely non-mechanical Liquid Crystal Waveguide Fourier Transform Spectrometer (LCWFTS) that will be suitable for a variety of remote-platform, in-situ measurements. These devices are made possible by novel electro-evanescent waveguide architecture, enabling "monolithic chip-scale" Electro Optic-FTS (EO-FTS) sensors. The potential performance of these EO-FTS sensors include: i) a spectral range throughout 0.4-5 μm (25000 - 2000 cm -1 ), ii) high-resolution (Δλ ≤ 0.1 nm), iii) high-speed (< 1 ms) measurements, and iv) rugged integrated optical construction. This performance potential enables the detection and quantification of a large number of different atmospheric gases simultaneously in the same air mass and the rugged construction will enable deployment on previously inaccessible platforms. The sensor construction is also amenable for analyzing aqueous samples on remote floating or submerged platforms. We will report a proof-of-principle prototype LCWFTS sensor that has been demonstrated in the near-IR (range of 1450-1700 nm) with a 5 nm resolution. This performance is in good agreement with theoretical models, which are being used to design and build the next generation LCWFTS devices.

New wide angle (270 degrees demonstrated), analog, 2-D electro-optic laser scanners will be presented. The low size, weight, and power requirements of these scanners expand the range of platforms that are suitable for optical sensors.

A new electro-optic waveguide platform, which provides unprecedented voltage control over optical phase delays (> 2mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), will be presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing their historic limitations. The waveguide geometry provides nematic relaxation speeds in the 10's of microseconds and LC scattering losses that are reduced by orders of magnitude from bulk transmissive LC optics. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: 2-D analog non-mechanical beamsteerers, chip-scale widely tunable lasers, chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay devices for phased array antennas, and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, FSO, laser illumination, phased array radar, etc. Performance attributes of several example devices and application data will be presented. In particular, we will present a non-mechanical beamsteerer that steers light in both the horizontal and vertical dimensions.

A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), is presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing historic limitations of liquid crystals. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: a 1-D non-mechanical, analog beamsteerer with an 80° field of regard, a chip-scale widely tunable laser, a chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay (up to 10 ns), and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

We are presenting a novel electro-optic architecture for non-mechanical laser beam steering with a demonstrated 80 degrees of steering in a chip-scale package. To our knowledge this is the largest angular coverage ever achieved by non-mechanical means. Even higher angular deflections are possible with our architecture both in the plane of the waveguide and out of the waveguide plane. In the present paper we describe the steering in the plane of the waveguide leaving the out-of-plane scanning mechanism to be detailed in a subsequent publication. In order to realize this performance we exploit an entirely new electro-optic architecture. Specifically, we utilize liquid crystals (LCs), which have the largest known electro-optic response, as an active cladding layer in an LC-waveguide geometry. This architecture exploits the benefits of liquid crystals (large tunable index), while circumventing historic LC limitations. LC-waveguides provide unprecedented macroscopic (>1 mm) electro-optic phase delays. When combined with patterned electrodes, this provides a truly analog, "Snell's-law-type" beam-steerer. With only two control electrodes we have realized an 80 degree field of view for 1550 nm light. Furthermore, the waveguide geometry keeps the light from ever coming into contact with an ITO electrode, thereby permitting high optical power transmission. Finally, the beamsteering devices have sub-millisecond response times.

A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), is presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing historic limitations of liquid crystals. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: a 1-D non-mechanical, analog beamsteerer with an 80° field of regard, a chip-scale widely tunable laser, a chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay (up to 10 ns), and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

Vescent Photonics Inc. and Jet Propulsion Lab are jointly developing an innovative ultra-compact (volume < 10 cm 3 ), ultra-low power (

We describe clinical and magnetic resonance (MR) features in a 69-year-old, Caucasian woman presenting with an unusual meningeal onset of cerebral schistosomiasis. Magnetic resonance work-up demonstrated supra- and infratentorial lesions with prominent brainstem involvement contrasting with the paucisymptomatic clinical presentation. Because of a recent stay in Uganda, including swimming in Lake Victoria, a diagnosis of neuroschistosomiasis was suggested. Serological tests and rectal biopsy confirmed the putative diagnosis. The patient was successfully treated with praziquantel at a dose of 50 mg/kg/day for 15 days. Brain MRI abnormalities improved dramatically within two months.

A new technology for performing high-precision Stokes polarimetry is presented. One traditional Stokes polarimetry configuration relies on mechanical devices such as rapidly rotating waveplates that are undesirable in vibration-sensitive optics experiments. Another traditional technique requires division of a light signal into four components that are measured individually; this technique is limited to applications in which signal levels are sufficient that intensity reduction does not diminish the signal-to-noise ratio. A new technology presented here is similar to the rotating waveplate approach, but two liquid crystal variable retarders (LCVR’s) are used instead of waveplates. A Stokes polarimeter instrument based on this technology has been made commercially-available. The theory of operation is detailed, and an accuracy assessment was conducted. Measurement reproducibility was verified and used to produce empirical estimates of uncertainty in measured components of a Stokes vector. Uncertainty propagation was applied to polarization parameters calculated from Stokes vector components to further the accuracy assessment. A calibrated polarimeter measures four Stokes components with 10-3 precision and average predicted uncertainties less than ±2x10-3. An experiment was conducted in which the linear polarization angles were measured with a LC polarimeter and with a photodiode for comparison. Observed discrepancies between polarization angle measurements made with a polarimeter and those made with a photodetector were nominally within ±0.3°.

Objectifs Notre but etait de comparer la perfusion par Resonance Magnetique Nucleaire (RMN) et la Tomographie par Emission de Positons (TEP) utilisant le carbone-11 Methionine (MET) dans le suivi des gliomes cerebraux et leur efficacite dans la differenciation recurrence tumorale et necrose tissulaire. Materiels et methodes Etude retrospective des dossiers de 28 patients atteints d’un gliome cerebral. Au total, 33 perfusions MR realisees de maniere concomitante a un TEP-Methionine sont analysees par comparaison entre le volume sanguin cerebral relatif (rCB V) et les resultats des examens TEP-MET. Les reproductibilites intra-et interobservateur ont ete evaluees. La valeur diagnostique du rCB V comparativement au TEP-MET et a l’histologie est evaluee par l’aire sous la courbe ROC. Resultats L’analyse de la courbe ROC montre que le rCBV a des performances au moins equivalentes au TEP-MET dans la differenciation recurrence tumorale et necrose. Le cut-off du rCBV dans la differenciation recurrence tumorale et necrose est de 182% avec une sensibilite de 81,5% et une specificite de 100%. Conclusion En pratique clinique, la perfusion MR pourrait remplacer le TEP-MET dans la differenciation recidive tumorale et necrose tissulaire.

This case report presents a 44-year-old woman with severe arterial ischemia leading to claudicatio and acute pain in rest caused by an ergotism. In the history was an abuse of suppositories containing caffeine and ergotamine induced by chronic headache. The initial angiography showed occlusions of the femoral arteries. After excluding other vascular diseases, intraarterial infusions of prostaglandin E were administered. Additionally, physiotherapeutic treatment followed. An progrediency of the symptoms made a epidural catheter for sympathicolysis and treatment of the acute pain necessary. As the results of this intervention were encouraging, a sympathetic blockade with injection of 96% ethanol at the level of L 2/3 and 3/4 was performed. After treatment, the clinical symptoms and the blood flow measured by Doppler ultrasonography normalised. A final angiography demonstrated a now normal arterial status. Ergotism, indication and methods of sympathetic blockades are discussed.

Reported here is the therapeutic efficacy of Tiapride with 10 10- to 17-yr.-old patients afflicted with severe stuttering problems. During the 20-wk. open, controlled study (baseline, low dose of Tiapride, high dose of Tiapride, follow-up observation without medication) the stuttering in various speech situations decreased markedly. No substantial change in different parameters of acoustic analysis and psychopathological characteristics accompanied the reduction in stuttering when group data were compared although positive effects concerning these variables could be seen in some cases. Several conclusions based on these results are presented. One assumed effect of the medication is improvement of central nervous regulatory mechanisms of speech motor coordination. Further, the value of the medication Tiapride in comprehensive stuttering therapy is discussed.

The actual state of research in childhood stuttering is presented and certain points open to criticism are discussed. We want to find answers to some of the open questions by means of a longitudinal study that starts at an early stage. In this study the prognostic validity of various dimensions of behaviour can be determined with regard to the development of stuttering. Thus, the conditions for the development of a valid and reliable instrument for early diagnosis are created that enable the specialist to estimate the probability of chronicity and to determine whether to treat or not to treat childhood stuttering. Furthermore, the study aims to develop a screening procedure which is easy to use for the persons in the child's surroundings (parents, teachers, physicians) so that stuttering children can be referred to a specialist at an earlier stage.

For about 15 months a multifactorial longitudinal study on the development of stuttering in preschool children has been conducted at the Phoniatric Outpatient Department of the University of Ulm. The main subject of the study is to determine valid indicators to estimate the risk of future chronicity or remission of stuttering and to find out whether and how it is possible to differentiate normal developmental dysfluencies from chronic abnormal dysfluencies. Preliminary results are presented and discussed.