3D motion strategy for online volumetric thermometry using simultaneous multi-slice EPI at 1.5T: an evaluation study

PURPOSE

In presence of respiratory motion, temperature mapping is altered by in-plane and through-plane displacements between successive acquisitions together with periodic phase variations. Fast 2D Echo Planar Imaging (EPI) sequence can accommodate intra-scan motion, but limited volume coverage and inter-scan motion remain a challenge during free-breathing acquisition since position offsets can arise between the different slices.

METHOD

To address this limitation, we evaluated a 2D simultaneous multi-slice EPI sequence with multiband (MB) acceleration during radiofrequency ablation on a mobile gel and in the liver of a volunteer (no heating). The sequence was evaluated in terms of resulting inter-scan motion, temperature uncertainty and elevation, potential false-positive heating and repeatability. Lastly, to account for potential through-plane motion, a 3D motion compensation pipeline was implemented and evaluated.

RESULTS

In-plane motion was compensated whatever the MB factor and temperature distribution was found in agreement during both the heating and cooling periods. No obvious false-positive temperature was observed under the conditions being investigated. Repeatability of measurements results in a 95% uncertainty below 2 °C for MB1 and MB2. Uncertainty up to 4.5 °C was reported with MB3 together with the presence of aliasing artifacts. Lastly, fast simultaneous multi-slice EPI combined with 3D motion compensation reduce residual out-of-plane motion.

CONCLUSION

Volumetric temperature imaging (12 slices/700 ms) could be performed with 2 °C accuracy or less, and offer tradeoffs in acquisition time or volume coverage. Such a strategy is expected to increase procedure safety by monitoring large volumes more rapidly for MR-guided thermotherapy on mobile organs.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

A fast MR-thermometry method for quantitative assessment of temperature increase near an implanted wire

PURPOSE

To propose a MR-thermometry method and associated data processing technique to predict the maximal RF-induced temperature increase near an implanted wire for any other MRI sequence.

METHODS

A dynamic single shot echo planar imaging sequence was implemented that interleaves acquisition of several slices every second and an energy deposition module with adjustable parameters. Temperature images were processed in real time and compared to invasive fiber-optic measurements to assess accuracy of the method. The standard deviation of temperature was measured in gel and in vivo in the human brain of a volunteer. Temperature increases were measured for different RF exposure levels in a phantom containing an inserted wire and then a MR-conditional pacemaker lead. These calibration data set were fitted to a semi-empirical model allowing estimation of temperature increase of other acquisition sequences.

RESULTS

The precision of the measurement obtained after filtering with a 1.6x1.6 mm2 in plane resolution was 0.2°C in gel, as well as in the human brain. A high correspondence was observed with invasive temperature measurements during RF-induced heating (0.5°C RMSE for a 11.5°C temperature increase). Temperature rises of 32.4°C and 6.5°C were reached at the tip of a wire and of a pacemaker lead, respectively. After successful fitting of temperature curves of the calibration data set, temperature rise predicted by the model was in good agreement (around 5% difference) with measured temperature by a fiber optic probe, for three other MRI sequences.

CONCLUSION

This method proposes a rapid and reliable quantification of the temperature rise near an implanted wire. Calibration data set and resulting fitting coefficients can be used to estimate temperature increase for any MRI sequence as function of its power and duration.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Assessment of left ventricle magnetic resonance temperature stability in patients in the presence of arrhythmias

BACKGROUND

Magnetic resonance (MR) thermometry allows visualization of lesion formation in real-time during cardiac radiofrequency (RF) ablation. The present study was performed to evaluate the precision of MR thermometry without RF heating in patients exhibiting cardiac arrhythmia in a clinical setting. The evaluation relied on quantification of changes in temperature measurements caused by noise and physiological motion.

METHODS

Fourteen patients referred for cardiovascular magnetic resonance imaging underwent an extra sequence to test the temperature mapping stability during free-breathing acquisition. Phase images were acquired using a multi-slice, cardiac-triggered, single-shot echo planar imaging sequence. Temperature maps were calculated and displayed in real-time while the electrocardiogram (ECG) was recorded. The precision of temperature measurement was assessed by measuring the temporal standard deviation and temporal mean of consecutive temperature maps over a period of three minutes. The cardiac cycle was analyzed from ECG recordings to quantify the impact of arrhythmia events on the precision of temperature measurement. Finally, two retrospective strategies were tested to remove acquisition dynamics related either to arrhythmia events or sudden breathing motion.

RESULTS

ECG synchronization allowed categorization of inter-beat intervals (RR) into distinct beat morphologies. Five patients were in stable sinus rhythm, while nine patients showed irregular RR intervals due to ectopic beats. An average temporal standard deviation of temperature of 1.6°C was observed in patients under sinus rhythm with a frame rate corresponding to the heart rate of the patient. The temporal standard deviation rose to 2.5°C in patients with arrhythmia. The retrospective rejection strategies increased the temperature precision measurement while maintaining a sufficient frame rate.

CONCLUSIONS

Our results indicated that real-time cardiac MR thermometry shows good precision in patients under clinical conditions, even in the presence of arrhythmia. By providing real-time visualization of temperature distribution within the myocardium during RF delivery, MR thermometry could prevent insufficient or excessive heating and thus improve safety and efficacy.

First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

The NOvA experiment has seen a 4.4σ signal of ν[over ¯]_{e} appearance in a 2 GeV ν[over ¯]_{μ} beam at a distance of 810 km. Using 12.33×10^{20} protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν[over ¯]_{μ}→ν[over ¯]_{e} candidates with a background of 10.3 and 102 ν[over ¯]_{μ}→ν[over ¯]_{μ} candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm_{32}^{2}|=2.48_{-0.06}^{+0.11}×10^{-3}  eV^{2}/c^{4} and sin^{2}θ_{23} in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ_{CP}=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ_{23} values in the upper octant by 1.6σ.

Myocardial Thermal Ablation with a Transesophageal High-Intensity Focused Ultrasound Probe: Experiments on Beating Heart Models

Described here is a study of transesophageal thermal ablation of isolated and perfused beating hearts and non-human primates. An endoscope integrating a transesophageal echocardiography probe and a high-intensity focused ultrasound transducer was built and tested on five Langendorff-isolated hearts and three 30-kg baboons. B-Mode ultrasound, passive elastography and magnetic resonance imaging were performed to monitor thermal lesions. In isolated hearts, continuous and gated sonication parameters were evaluated with acoustic intensities of 9-12 W/cm². Sonication parameters of gated exposures with 12 W/cm² acoustic intensity for 5 min consistently produced visible lesions in the ventricles of isolated hearts. In animals, left atria and ventricles were exposed to repeated continuous sonications (4-15 times for 16 s) at an acoustic intensity at the surface of the transducer of 9 W/cm². Clinical states of the baboons during and after the treatment were good. One suspected lesion in the left ventricle could be evidenced by elastography, but was not confirmed by magnetic resonance imaging. The transesophageal procedure therefore has the potential to create thermal lesions in beating hearts and its safety in clinical practice seems promising. However, further technical exploration of the energy deposition in the target would be necessary before the next pre-clinical experiments.

Real-time 3D ultrasound based motion tracking for the treatment of mobile organs with MR-guided high-intensity focused ultrasound

INTRODUCTION

Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) treatments of mobile organs require locking the HIFU beam on the targeted tissue to maximise heating efficiency. We propose to use a standalone 3 D ultrasound (US)-based motion correction technique using the HIFU transducer in pulse-echo mode. Validation of the method was performed in vitro and in vivo in the liver of pig under MR-thermometry.

METHODS

3 D-motion estimation was implemented using ultrasonic speckle-tracking between consecutive acquisitions. Displacement was estimated along four sub-apertures of the HIFU transducer by computing the normalised cross-correlation of backscattered signals followed by a triangulation algorithm. The HIFU beam was steered accordingly and energy was delivered under real-time MR-thermometry (using the proton resonance frequency shift method with online motion compensation and correction of associated susceptibility artefacts). An MR-navigator echo was used to assess the quality of the US-based motion correction.

RESULTS

Displacement estimations from US measurements were in good agreement with 1 D MR-navigator echo readings. In vitro, the maximum temperature increase was improved by 37% as compared to experiments performed without motion correction and temperature distribution remained much more focussed. Similar results were reported in vivo, with an increase of 35% on the maximum temperature using this US-based HIFU target locking.

CONCLUSION

This standalone 3D US-based motion correction technique is robust and allows maintaining the HIFU focal spot in the presence of motion without adding any burden or complexity to MR thermal imaging. In vitro and in vivo results showed about 35% improvement in heating efficiency when focus position was locked on the target using the proposed technique.

Feasibility of real-time MR thermal dose mapping for predicting radiofrequency ablation outcome in the myocardium in vivo

BACKGROUND

Clinical treatment of cardiac arrhythmia by radiofrequency ablation (RFA) currently lacks quantitative and precise visualization of lesion formation in the myocardium during the procedure. This study aims at evaluating thermal dose (TD) imaging obtained from real-time magnetic resonance (MR) thermometry on the heart as a relevant indicator of the thermal lesion extent.

METHODS

MR temperature mapping based on the Proton Resonance Frequency Shift (PRFS) method was performed at 1.5 T on the heart, with 4 to 5 slices acquired per heartbeat. Respiratory motion was compensated using navigator-based slice tracking. Residual in-plane motion and related magnetic susceptibility artifacts were corrected online. The standard deviation of temperature was measured on healthy volunteers (N = 5) in both ventricles. On animals, the MR-compatible catheter was positioned and visualized in the left ventricle (LV) using a bSSFP pulse sequence with active catheter tracking. Twelve MR-guided RFA were performed on three sheep in vivo at various locations in left ventricle (LV). The dimensions of the thermal lesions measured on thermal dose images, on 3D T1-weighted (T1-w) images acquired immediately after the ablation and at gross pathology were correlated.

RESULTS

MR thermometry uncertainty was 1.5 °C on average over more than 96% of the pixels covering the left and right ventricles, on each volunteer. On animals, catheter repositioning in the LV with active slice tracking was successfully performed and each ablation could be monitored in real-time by MR thermometry and thermal dosimetry. Thermal lesion dimensions on TD maps were found to be highly correlated with those observed on post-ablation T1-w images (R = 0.87) that also correlated (R = 0.89) with measurements at gross pathology.

CONCLUSIONS

Quantitative TD mapping from real-time rapid CMR thermometry during catheter-based RFA is feasible. It provides a direct assessment of the lesion extent in the myocardium with precision in the range of one millimeter. Real-time MR thermometry and thermal dosimetry may improve safety and efficacy of the RFA procedure by offering a reliable indicator of therapy outcome during the procedure.

Combination of principal component analysis and optical-flow motion compensation for improved cardiac MR thermometry

The use of magnetic resonance (MR) thermometry for the monitoring of thermal ablation is rapidly expanding. However, this technique remains challenging for the monitoring of the treatment of cardiac arrhythmia by radiofrequency ablation due to the heart displacement with respiration and contraction. Recent studies have addressed this problem by compensating in-plane motion in real-time with optical-flow based tracking technique. However, these algorithms are sensitive to local variation of signal intensity on magnitude images associated with tissue heating. In this study, an optical-flow algorithm was combined with a principal component analysis method to reduce the impact of such effects. The proposed method was integrated to a fully automatic cardiac MR thermometry pipeline, compatible with a future clinical workflow. It was evaluated on nine healthy volunteers under free breathing conditions, on a phantom and in vivo on the left ventricle of a sheep. The results showed that local intensity changes in magnitude images had lower impact on motion estimation with the proposed method. Using this strategy, the temperature mapping accuracy was significantly improved.

Magnetic resonance-compatible model of isolated working heart from large animal for multimodal assessment of cardiac function, electrophysiology, and metabolism

To provide a model close to the human heart, and to study intrinsic cardiac function at the same time as electromechanical coupling, we developed a magnetic resonance (MR)-compatible setup of isolated working perfused pig hearts. Hearts from pigs (40 kg, n = 20) and sheep (n = 1) were blood perfused ex vivo in the working mode with and without loaded right ventricle (RV), for 80 min. Cardiac function was assessed by measuring left intraventricular pressure and left ventricular (LV) ejection fraction (LVEF), aortic and mitral valve dynamics, and native T1 mapping with MR imaging (1.5 Tesla). Potential myocardial alterations were assessed at the end of ex vivo perfusion from late-Gadolinium enhancement T1 mapping. The ex vivo cardiac function was stable across the 80 min of perfusion. Aortic flow and LV-dP/dtmin were significantly higher (P < 0.05) in hearts perfused with loaded RV, without differences for heart rate, maximal and minimal LV pressure, LV-dP/dtmax, LVEF, and kinetics of aortic and mitral valves. T1 mapping analysis showed a spatially homogeneous distribution over the LV. Simultaneous recording of hemodynamics, LVEF, and local cardiac electrophysiological signals were then successfully performed at baseline and during electrical pacing protocols without inducing alteration of MR images. Finally, (31)P nuclear MR spectroscopy (9.4 T) was also performed in two pig hearts, showing phosphocreatine-to-ATP ratio in accordance with data previously reported in vivo. We demonstrate the feasibility to perfuse isolated pig hearts in the working mode, inside an MR environment, allowing simultaneous assessment of cardiac structure, mechanics, and electrophysiology, illustrating examples of potential applications.

Improved cardiac magnetic resonance thermometry and dosimetry for monitoring lesion formation during catheter ablation

PURPOSE

A new real-time MR-thermometry pipeline was developed to measure multiple temperature images per heartbeat with 1.6×1.6×3 mm³ spatial resolution. The method was evaluated on 10 healthy volunteers and during radiofrequency ablation (RFA) in sheep.

METHODS

Multislice, electrocardiogram-triggered, echo-planar imaging was combined with parallel imaging, under free breathing conditions. In-plane respiratory motion was corrected on magnitude images by an optical flow algorithm. Motion-related susceptibility artifacts were compensated on phase images by an algorithm based on Principal Component Analysis. Correction of phase drift and temporal filter were included in the pipeline implemented in the Gadgetron framework. Contact electrograms were recorded simultaneously with MR thermometry by an MR-compatible ablation catheter.

RESULTS

The temporal standard deviation of temperature in the left ventricle remained below 2 °C on each volunteer. In sheep, focal heated regions near the catheter tip were observed on temperature images (maximal temperature increase of 38 °C) during RFA, with contact electrograms of acceptable quality. Thermal lesion dimensions at gross pathology were in agreement with those observed on thermal dose images.

CONCLUSION

This fully automated MR thermometry pipeline (five images/heartbeat) provides direct assessment of lesion formation in the heart during catheter-based RFA, which may improve treatment of cardiac arrhythmia by ablation. Magn Reson Med 77:673-683, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Site-specific conformational determination in thermal unfolding studies of helical peptides using vibrational circular dichroism with isotopic substitution

Understanding the detailed mechanism of protein folding requires dynamic, site-specific stereochemical information. The short time response of vibrational spectroscopies allows evaluation of the distribution of populations in rapid equilibrium as the peptide unfolds. Spectral shifts associated with isotopic labels along with local stereochemical sensitivity of vibrational circular dichroism (VCD) allow determination of the segment sequence of unfolding. For a series of alanine-rich peptides that form alpha-helices in aqueous solution, we used isotopic labeling and VCD to demonstrate that the alpha-helix noncooperatively unwinds from the ends with increasing temperature. For these blocked peptides, the C-terminal is frayed at 5 degrees C. Ab initio level theoretical simulations of the IR and VCD band shapes are used to analyze the spectra and to confirm the conformation of the labeled components. The VCD signals associated with the labeled residues are amplified by coupling to the nonlabeled parts of the molecule. Thus small labeled segments are detectable and stereochemically defined in moderately large peptides in this report of site-specific peptide VCD conformational analysis.

Vibrational circular dichroism of tetraphenylporphyrin in peptide complexes? A computational study

The Raman and absorption spectra of tetraphenylporphyrin (TPP) were calculated and compared to experiment. The computation was based on the harmonic molecular force field and electric tensors obtained ab initio at the BPW91/6-31G* level. Good agreement was found between experimental and calculated frequencies and intensities. In order to estimate whether induced optical activity in chiral complexes interferes with the signal of peptide vibrations, the vibrational circular dichroism (VCD) spectra of TPP were simulated. The magnetic field perturbation theory (MFP) and the gauge-invariant atomic orbitals (GIAO) were used for the simulation. Such spectra were compared to theoretical VCD intensities of a model tripeptide as well to experimental spectra of a complex of the peptide and tetrakis(p-sulfonatophenyl)porphyrin (TSPP). No significant contribution to VCD signal from the TPP residue was found in experimental spectra. Thus, possible peptide conformational changes occurring during the complexation can be monitored directly in the amide I frequency region.

Simulations of oligopeptide vibrational CD: effects of isotopic labeling

Simulated ir absorption and vibrational CD (VCD) spectra of four alanine-based octapeptides, each having its main chain constrained to a different secondary structure conformation, were analyzed and compared with experimental results for several different peptides. The octapeptide simulations were based on transfer of property tensors from a series of ab initio calculations for a short L-alanine based segment containing 3 peptide bonds with relative straight phi, psi angles fixed to those appropriate for alpha-helix, 3(10)-helix, ProII-like helix, and beta-sheet-like strand. The tripeptide force field (FF) and atomic polar tensors were obtained with density functional theory techniques at the BPW91/6-31G** level and the atomic axial tensor at the mixed BPW91/6-31G**/HF/6-31G level. Allowing for frequency correction due to the FF limitations, the octapeptide results obtained are qualitatively consistent with experimental observations for ir and VCD spectra of polypeptides and oligopeptides in established conformations. In all cases, the correct VCD sign patterns for the amide I and II bands were predicted, but the intensities did have some variation from the experimental patterns. Predicted VCD changes upon deuteration of either the peptide or side-chains as well as for (13)C isotopic labeling of the amide C=O at specific sites in the peptide chain were computed for analysis of experimental observations. A combination of theoretical modeling with experimental data for labeled compounds leads both to enhanced resolution of component transitions and added conformational applicability of the VCD spectra.

Skeletal vibrational circular dichroism of a series of bicyclic dilactones: the fingerprint region?

The vibrational circular dichroism (VCD) spectra of 2,5-dioxabicyclo[2.2.1]heptane-3,6-dione 1 (R = H) and the 1,4-dialkyl derivatives, 1 (R = Me) and 1 (R = t-Bu), were calculated by the ab initio magnetic field perturbation (MFP) procedure with a B3LYP/6-31G* force field, and the VCD spectra of the dimethyl and di-t-butyl derivatives were measured in the region 800-1500 cm-1. While the absolute configurations of 1 (R = Me) and 1 (R = t-Bu) could be assigned unambiguously by comparison of the experimental and predicted spectra, there is little obvious correspondence between the spectra of the series of compounds. The VCD spectra are analysed on the basis of operation of a coupled oscillator mechanism involving motions of the polar bonds. In the case of the parent dihydro system, bridgehead C-H bond motions appear to dominate contributions to the VCD of vibrational transitions into which they are mixed.Key words: vibrational circular dichroism (VCD), 2,5-dioxabicyclo[2.2.1]heptane-3,6-dione, dilactones, optical activity.

[Synthesis of collagen in culture of endothelial cells of the human umbilical vein. Effects of cyclosporine A]

Interstitial renal fibrosis and gingival hypertrophy are frequent side-effects of cyclosporin A which have been attributed to a dysfunction of extracellular matrix synthesis. Endothelial cells might participate in the matrix accumulation observed. We studied the effects of increasing concentrations of cyclosporin A on protein synthesis by human umbilical vein endothelial cells. Collagen synthesis decreased significantly to 800 ng/ml in both medium and cell layer. The percentage of hydroxylation of its proline residues decreased significantly as from 400 ng/ml. The main proteins, analysed by SDS-PAGE, were thrombospondin, fibronectin and the alpha 1 and alpha 2 chains of type IV collagen. These fractions did not show any change after 24 hours exposure to 200 ng/ml of cyclosporin A. These results demonstrate an inhibitory effect of cyclosporin A on collagen synthesis by human umbilical vein endothelial cells. Consequently, matrix accumulation by increased collagen synthesis in cyclosporin A treated patient may not be directly related to the drug effect on endothelial cells.

Aneurysms of the extracranial internal carotid artery due to fibromuscular dysplasia: results of surgical management

Between January 1977 and December 1990, eight patients underwent surgical correction of aneurysms of the extracranial internal carotid artery due to fibromuscular dysplasia. Mean age of patients was 50 years (range 31 to 70 years). Five patients presented with neurologic hemispheric symptoms. Most aneurysms were saccular and occurred preferentially at the level of C2 or C3. All of these patients underwent operation through conventional cervicotomy. Resection-anastomosis was performed in three cases whereas resection-graft was performed in five. Histopathological examination of the eight specimens was consistent with fibromuscular dysplasia of the media. There was no central nervous system-related mortality and morbidity. Seven patients were alive and free of new neurological manifestations at mean follow-up of 156 months (18 to 180 months). One patient died of myocardial infarction at 96 months. All patients had postoperative duplex scanning or arteriograms. These revealed that carotid restorations were patent in seven whereas one patient had asymptomatic occlusion at 18 months.

Persistent proatlantal artery associated with carotid artery stenosis treatment by percutaneous transluminal balloon angioplasty

A 58-year-old man had an asymptomatic tight stenosis of the internal carotid artery associated with a persistent proatlantal artery. This as well as other compositional arterial anomalies of the basilar artery were discovered on arteriograms. The stenosis was successfully treated by percutaneous transluminal balloon angioplasty. Therapeutic choices are discussed in this setting because of the risk of carotid clamping in the presence of persistent carotid-basilar anastomoses.

Aortoappendicular fistula after aortoiliac prosthetic replacement

A 48-year-old patient who had had an aortofemoral reconstruction with a Dacron graft nine years earlier presented with intestinal bleeding. At laparotomy the cause was found to be a fistula between a proximal false aneurysm and the vermiform appendix. The patient recovered after removal of the graft and extraanatomic revascularization associated with appendectomy. Four other similar case reports have been found in the literature.

[The ambitio-impulse different from narcissism]

We should not let our dynamic drive bog down in the ambiguous concept of "libido". A concept which disturbed Freud himself as is clearly demonstrated in his latest works and which has been considerably misused afterwards. In order to achieve this aim we have in the light of psychopathology, of the symbolic nature of dreams and of our own personal experience set to describe three fundamental drives-the real roots of Man unseparable from his constitution-namely 1. ambitio: (which prompts Man to assert himself, to develop and dominate); 2. agressio: (the urge to defend our internal territory or to overcome obstacles according to our will); 3. attractio: (the disposition to be moved or attracted by this or that object). The present paper shall deal with ambitio which is not to be mixed up with conscious ambition. This unconscious drive, axial and archaic which nourishes the evolution of all living matter (even a tree trunk) should not be interspersed with guilt but is indispensable to our emergence from the Cosmos. Ambitio can be subject to hypertrophy by a compensatory process in cases of megalomania and on the contrary it can be atrophied in the case of a failure syndrome or inferiority complex for example. The most delicate stage of the process is that of its taming and of its conscious acceptance. All things which if properly dealt with and if we want to avoid the traps of authoritarianism or of the narcissistic delusion will lead us in the interest of others, to the most realistic modesty.

[The contribution of Jacob Lévy Moreno]

meeting of two days organized has happened at the Chartreuse C.H.S., the 24th and the 25th of March 1983, to give homage to J.-L. Moreno , founder of the groupe dynamic and of the psychodrama, insufficiently honoured in France, it looks. Living exchanges have allowed us to draw the mean lines of his technical innovations based of spontaneousity since "the empty chair", "the doble " and "the upsetting of parts", till the sociometric diagram allowing to locate the interactions in the groupe . Then, the different extensions of the therapeutical psychodrama have been developed, practiced since 35 years in Saint- Venant and in Dijon , according to a original method different with nevrosed illmen and with psychotic patients, those one profiting of "intermediate objects", making easier the relationships. The theater, the groupe psychanalyse , or more recently the development of technics makings intervention of somatic and bio- energetical dimension, have settled fruisful extension of the Moreno 's initiative. It is necessary to locate these activities in the universal and humanist context and in the "living will" of the author.