Showing papers by "University of Grenoble published in 2004"

Observation and properties of the X(3872) decaying to J/ψπ+π- in pp̄ collisions at √s = 1.96 TeV

Abstract: We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in p (p) over bar collisions at roots=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.

How does deep brain stimulation work? Present understanding and future questions.

Abstract: High-frequency deep brain stimulation (DBS) of the thalamus or basal ganglia represents an effective clinical technique for the treatment of several medically refractory movement disorders (e.g., Parkinson's disease, essential tremor, and dystonia). In addition, new clinical applications of DBS for other neurologic and psychiatric disorders (e.g., epilepsy and obsessive-compulsive disorder) have been vaulted forward. Although DBS has been effective in the treatment of movement disorders and is rapidly being explored for the treatment of other neurologic disorders, the scientific understanding of its mechanisms of action remains unclear and continues to be debated in the scientific community. Optimization of DBS technology for present and future therapeutic applications will depend on identification of the therapeutic mechanism(s) of action. The goal of this review is to address the present knowledge of the effects of high frequency stimulation within the central nervous system and comment on the functional implications of this knowledge for uncovering the mechanism(s) of DBS. Four general hypotheses have been developed to explain the mechanism(s) of DBS: depolarization blockade, synaptic inhibition, synaptic depression, and stimulation-induced modulation of pathologic network activity. Using the results from microdialysis, neural recording, functional imaging, and neural modeling experiments, the authors address the main hypotheses and attempt to reconcile what have been considered conflicting results from different research modalities.

Deep brain stimulation

Abstract: During the last decade deep brain stimulation (DBS) has become a routine method for the treatment of advanced Parkinson's disease (PD), leading to striking improvements in motor function and quality of life of PD patients. It is associated with minimal morbidity. The rationale of targeting specific structures within basal ganglia such as the subthalamic nucleus (STN) or the internal segment of the globus pallidus (GPi) is strongly supported by the current knowledge of the basal ganglia pathophysiology, which is derived from extensive experimental work and which provides the theoretical basis for surgical therapy in PD. In particular, the STN has advanced to the worldwide most used target for DBS in the treatment of PD, due to the marked improvement of all cardinal symptoms of the disease. Moreover on-period dyskinesias are reduced in parallel with a marked reduction of the equivalent daily levodopa dose following STN-DBS. The success of the therapy largely depends on the selection of the appropriate candidate patients and on the precise implantation of the stimulation electrode, which necessitates careful imaging-based pre-targeting and extensive electrophysiological exploration of the target area. Despite the clinical success of the therapy, the fundamental mechanisms of high-frequency stimulation are still not fully elucidated. There is a large amount of evidence from experimental and clinical data that stimulation frequency represents a key factor with respect to clinical effect of DBS. Interestingly, high-frequency stimulation mimics the functional effects of ablation in various brain structures. The main hypotheses for the mechanism of high-frequency stimulation are: (1) depolarization blocking of neuronal transmission through inactivation of voltage dependent ion-channels, (2) jamming of information by imposing an efferent stimulation-driven high-frequency pattern, (3) synaptic inhibition by stimulation of inhibitory afferents to the target nucleus, (4) synaptic failure by stimulation-induced neurotransmitter depletion. As the hyperactivity of the STN is considered a functional hallmark of PD and as there is experimental evidence for STN-mediated glutamatergic excitotoxicity on neurons of the substantia nigra pars compacta (SNc), STN-DBS might reduce glutamatergic drive, leading to neuroprotection. Further studies will be needed to elucidate if STN-DBS indeed provides a slow-down of disease progression.

Circumstances of discovery of phaeochromocytoma: a retrospective study of 41 consecutive patients.

Abstract: Objective: Phaeochromocytoma is a rare tumour of the chromaffin cells, the diagnosis of which is based on an assay of metanephrines and treatment is surgical excision of the tumour. It is usually discovered due to a rich and varied symptomatology or classic paroxysmal hypertension. The main purpose of this study was to specify the exact circumstances of discovery of the phaeochromocytomas operated on in our university hospital between 1990 and 2002. Design and methods: Forty-one consecutive and complete case reports of patients who had surgery for phaeochromocytoma were analysed retrospectively. This series includes 10 patients with a genetic disorder predisposing to phaeochromocytoma. Results: The association of headaches and palpitations with sweating was found in only 24% of cases (10/41). Blood pressure anomalies led to the discovery of phaeochromocytoma in only 51% of cases (21/41) and 59% (24/41) of all the patients suffered from hypertension. In almost half the cases (20/41), the tumour was discovered by an imaging method (ultrasonography, CT scan or MRI) which had been performed for reasons unrelated to a blood pressure abnormality. Conclusions: Phaeochromocytoma, the symptoms of which are not very specific and during which hypertension is present in only half the patients, is a disease that remains rare. Its incidence could be increasing because of changes in the method of detection. Indeed, in our study, different imaging techniques led to its incidental discovery in half of the cases.

Mitochondrial defects and heterogeneous cytochrome c release after cardiac cold ischemia and reperfusion.

Abstract: Mitochondria play a critical role in myocardial cold ischemia-reperfusion (CIR) and induction of apoptosis. The nature and extent of mitochondrial defects and cytochrome c (Cyt c) release were determined by high-resolution respirometry in permeabilized myocardial fibers. CIR in a rat heart transplant model resulted in variable contractile performance, correlating with the decline of ADP-stimulated respiration. Respiration with succinate or N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride (substrates for complexes II and IV) was partially restored by added Cyt c, indicating Cyt c release. In contrast, NADH-linked respiration (glutamate+malate) was not stimulated by Cyt c, owing to a specific defect of complex I. CIR but not cold ischemia alone resulted in the loss of NADH-linked respiratory capacity, uncoupling of oxidative phosphorylation and Cyt c release. Mitochondria depleted of Cyt c by controlled hypoosmotic shock provided a kinetic model of homogeneous Cyt c depletion. Comparison to Cyt c control of respiration in CIR-injured myocardial fibers indicated heterogeneity of Cyt c release. The complex I defect and uncoupling correlated with heterogeneous Cyt c release, the extent of which increased with loss of cardiac performance. These results demonstrate a complex pattern of multiple mitochondrial damage as determinants of CIR injury of the heart.

Complex lithospheric structure under the central Baltic Shield from surface wave tomography

Abstract: Complex lithospheric structure under the central Baltic Shield from surface wave tomography

Parity-violating electroweak asymmetry in ep scattering

Abstract: We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from protons. Significant contributions to this asymmetry could arise from the contributions of strange form factors in the nucleon. The measured asymmetry is $A=\ensuremath{-}15.05\ifmmode\pm\else\textpm\fi{}0.98(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.56(\mathrm{syst})\phantom{\rule{0.3em}{0ex}}\mathrm{ppm}$ at the kinematic point $⟨{\ensuremath{\theta}}_{\mathrm{lab}}⟩=12.3\ifmmode^\circ\else\textdegree\fi{}$ and $⟨{Q}^{2}⟩=0.477\phantom{\rule{0.3em}{0ex}}{(\mathrm{GeV}∕c)}^{2}$. Based on these data as well as data on electromagnetic form factors, we extract the linear combination of strange form factors ${G}_{E}^{s}+0.392{G}_{M}^{s}=0.014\ifmmode\pm\else\textpm\fi{}0.020\ifmmode\pm\else\textpm\fi{}0.010$, where the first error arises from this experiment and the second arises from the electromagnetic form factor data. This paper provides a full description of the special experimental techniques employed for precisely measuring the small asymmetry, including the first use of a strained GaAs crystal and a laser-Compton polarimeter in a fixed target parity-violation experiment.

First detection of polarization of the submillimetre diffuse galactic dust emission by Archeops

Abstract: We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon--borne instrument was launched by CNES from the Swedish Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency bands dedicated to CMB studies, Archeops had one 545 GHz and six 353 GHz bolometers mounted in three polarization sensitive pairs that were used for Galactic foreground studies. We present maps of the I, Q, U Stokes parameters over 17% of the sky and with a 13 arcmin resolution at 353 GHz (850 microns). They show a significant Galactic large scale polarized emission coherent on the longitude ranges [100, 120] and [180, 200] deg. with a degree of polarization at the level of 4-5%, in agreement with expectations from starlight polarization measurements. Some regions in the Galactic plane (Gem OB1, Cassiopeia) show an even stronger degree of polarization in the range 10-20%. Those findings provide strong evidence for a powerful grain alignment mechanism throughout the interstellar medium and a coherent magnetic field coplanar to the Galactic plane. This magnetic field pervades even some dense clouds. Extrapolated to high Galactic latitude, these results indicate that interstellar dust polarized emission is the major foreground for PLANCK-HFI CMB polarization measurement.

Geodynamic and metabolic cycles in the Hadean

Abstract: . High-degree melting of hot dry Hadean mantle at ocean ridges and plumes resulted in a crust about 30km thick, overlain in places by extensive and thick mafic volcanic plateaus. Continental crust, by contrast, was relatively thin and mostly submarine. At constructive and destructive plate boundaries, and above the many mantle plumes, acidic hydrothermal springs at ~400°C contributed Fe and other transition elements as well as P and H2 to the deep ocean made acidulous by dissolved CO2 and minor HCl derived from volcanoes. Away from ocean ridges, submarine hydrothermal fluids were cool (≤100°C), alkaline (pH ~10), highly reduced and also H2-rich. Reaction of solvents in this fluid with those in ocean water was catalyzed in a hydrothermal mound, a natural self-restoring flow reactor and fractionation column developed above the alkaline spring. The mound consisted of brucite, Mg-rich clays, ephemeral carbonates, Fe-Ni sulfide and green rust. Acetate and glycine were the main products, some of which were eluted to the ocean. The rest, along with other organic byproducts were retained and concentrated within Fe-Ni sulfide compartments. These compartments, comprising the natural hydrothermal reactor, consisted partly of greigite (Fe5NiS8). It was from reactions between organic modules confined within these inorganic compartments that the first prokaryotic organism evolved. These acetogenic precursors to the bacteria diversified and migrated down the mound and into the ocean floor to inaugurate the "deep biosphere". Once there they were protected from cataclysmic heating events caused by large meteoritic impacts. Geodynamic forces led to the eventual obduction of the deep biosphere into the photic zone where, initially protected by a thin veneer of sediment, the use of solar energy was mastered and photosynthesis emerged. The further evolution to oxygenic photosynthesis was effected as catalytic [Mn,Ca]-bearing molecules that otherwise would have been interred in minerals such as rancieite and hollandite in shallow marine manganiferous sediments, were sequestered and invaginated within the cyanobacterial precursor where, energized by light, they could oxidize water. Thus, a chemical sedimentary environment was required both for the emergence of chemosynthesis and of oxygenic photosynthesis, the two innovations that did most to change the nature of our planet.

The titration of clay minerals: I. Discontinuous backtitration technique combined with CEC measurements

Abstract: Previous experimental studies on clay potentiometric titration have been unable to distinguish inorganic cation exchange in the interlayer and on basal plane surfaces from specific pH-dependent sorption of cations and anions on the edges. In this study, we refined a titration technique, combining discontinuous backtitration and cation exchange capacity (CEC) measurements, and applied it to the potentiometric titration of Na- and Ca-conditioned montmorillonites. This technique can be used to accurately measure cation exchange, edge surface proton charge, dissolution of clay, and precipitation of new phases. Thus, a precise measurement of the variations of net proton surface charge is possible. This has important implications for clay surface modeling (see part II of this article) and for processes that depend on the clay surface charge, e.g., alteration, rheological processes, and contamination retention applications. In addition, this study confirms the adsorption of ionic pairs such as CaCl+ in exchange site positions and shows that CaOH+ could behave like CaCl+. This result, together with the evidence of precipitation of a Ca---Si phase over a short time-scale (1 week) at high pH and low temperature, can be used to model clay–concrete interactions more accurately. We confirmed and quantified the H+/Na+ exchange reaction at low pH. Finally, we demonstrate that both the edge surface charge and the permanent structural charge are compensated for by the nonspecific sorption of cations from solution across the entire pH range from 4 to 11. Under these conditions, the surface potential is fully screened and does not need to be invoked in modeling sorption processes on clay particles in dilute suspensions.

R-parity violating supersymmetry

Abstract: Theoretical and phenomenological implications of R-parity violation in supersymmetric theories are discussed in the context of particle physics and cosmology. Fundamental aspects include the relation with continuous and discrete symmetries and the various allowed patterns of R-parity breaking. Recent developments on the generation of neutrino masses and mixings within different scenarios of R-parity violation are discussed. The possible contribution of R-parity-violating Yukawa couplings in processes involving virtual supersymmetric particles and the resulting constraints are reviewed. Finally, direct production of supersymmetric particles and their decays in the presence of R-parity-violating couplings is discussed together with a survey of existing constraints from collider experiments.

The ELODIE survey for northern extra-solar planets. III. Three planetary candidates detected with ELODIE

Abstract: We present our ELODIE radial-velocity measurements of HD 74156 and 14 Her (HD 145675). These stars ex- hibit low-amplitude radial-velocity variations induced by the presence of low-mass companions. The radial-velocity data of HD 74156 reveal the presence of two planetary companions: a 1.86 MJup planet on a 51.64-d orbit and a 6.2 MJup planet on a long-period (� 5.5 yr) orbit. Both orbits are fairly eccentric (e = 0.64 and 0.58). The 4.7 MJup companion to 14 Her has a long period (4.9 yr) and a moderately eccentric orbit (e = 0.34). We detect an additional linear radial-velocity trend superimposed on the periodic signal for this star. We also compute updated orbital solutions for HD 209458 and 51 Peg (HD 217014). Finally, we present our ELODIE radial-velocity data and orbital solutions for 5 stars known to host planetary companions: Ups And (HD 9826), 55 Cnc (HD 75732), 47 UMa (HD 95128), 70 Vir (HD 117176) and HD 187123. We confirm the previously pub- lished orbital solutions for Ups And, 70 Vir and HD 187123. Our data are not sufficient to fully confirm the orbital solutions for 55 Cnc and 47 UMa.

Verapamil and its derivative trigger apoptosis through glutathione extrusion by multidrug resistance protein MRP1.

Abstract: This study demonstrates that verapamil and a newly synthesized verapamil derivative, NMeOHI 2 , behave as apoptogens in multidrug resistance protein 1 (MRP1)-expressing cells. When treated with either verapamil or NMeOHI 2 , surprisingly, baby hamster kidney-21 (BHK) cells transfected with human MRP1 were killed. Because parental BHK cells were not, as well as cells expressing an inactive (K1333L) MRP1 mutant, this indicated that cell death involved functional MRP1 transporter. Cell death was identified as apoptosis by using annexin V-fluorescein labeling and was no longer observed in the presence of the caspase inhibitor Z-Val-Ala-Asp(OMe)-CH 2 F (Z-VAD-FMK). In vitro , both verapamil and its derivative inhibited leukotriene C4 transport by MRP1-enriched membrane vesicles in a competitive manner, with a K i of 48.6 μm for verapamil and 5.5 μm for NMeOHI 2, and stimulated reduced glutathione (GSH) transport 3-fold and 9-fold, respectively. Treatment of MRP1-expressing cells with either verapamil or the derivative quickly depleted intracellular GSH content with a strong decrease occurring in the first hour of treatment, which preceded cell death beginning at 8–16 h. Furthermore, addition of GSH to the media efficiently prevented cell death. Therefore, verapamil and its derivative trigger apoptosis through stimulation of GSH extrusion mediated by MRP1. This new information on the mechanism of induced apoptosis of MDR cells may represent a novel approach in the selective treatment of MRP1-positive tumors.

Mixing Microworld and Cas Features in Building Computer Systems that Help Students Learn Algebra

Abstract: We present the design principles for a new kind of computer system that helps students learn algebra The fundamental idea is to have a system based on the microworld paradigm that allows students to make their own calculations, as they do with paper and pencil, without being obliged to use commands, and to verify the correctness of these calculations This requires an advanced editor for algebraic expressions, an editor for algebraic reasoning and an algorithm that calculates the equivalence of two algebraic expressions A second feature typical of microworlds is the ability to provide students information about the state of the problem in order to help them move toward a solution A third feature comes from the CAS (Computer Algebra System) paradigm, consisting of providing commands for executing certain algebraic actions; these commands have to be adapted to the current level of understanding of the students in order to only present calculations they can do without difficulty With this feature, such a computer system can provide an introduction to the proper use of a Computer Algebra System We have implemented most of these features in a computer system called aplusix for a sub-domain of algebra, and we have done several experiments with students (mainly grades 9 and 10) We had good results, with positive feedback from students and teachers aplusix is currently a prototype that can be downloaded from http://aplusiximagfr It will become a commercial product during 2004

Globus pallidus internus stimulation in primary generalized dystonia: a H215O PET study.

Abstract: Globus pallidus internus (GPi) deep brain stimulation (DBS) increasingly shows promising efficacy in the treatment of severe primary generalized dystonia. Functional imaging studies have shown previously that dystonia could be related to abnormal cortical activation during voluntary movement. In the present study, the effects of GPi DBS on regional cerebral blood flow (rCBF) during a motor task were studied in patients with primary generalized dystonia. rCBF was measured using H215O and PET in eight control subjects and six patients with dystonia treated with bilateral GPi DBS. Subjects were scanned at rest and while performing joystick movements. Dystonic patients were tested in two conditions: 'OFF' (stimulator bilaterally switched off) and 'ON' (unilateral stimulation). In the 'OFF' condition, compared with rest, motor activation of the most dystonic hand was associated with overactivity in the contralateral dorsolateral prefrontal cortex, gyrus frontalis medialis, superior frontal gyrus (area 10), frontoorbital cortex and thalamus. In the 'ON' condition, GPi DBS contralaterally to the most dystonic hand induced a decrease of the overactivation in the same areas, as well as the putamen. According to the present study, generalized dystonia is associated with prefrontal overactivation which can be reversed by effective GPi DBS.

New neighbours. III. 21 new companions to nearby dwarfs, discovered with adaptive optics ⋆

Abstract: Received ; accepted Abstract. We present some results of a CFHT adaptive optics search for companions to nearby dwarfs. We identify 21 new components in solar neighbourhood systems, of which 13 were found while surveying a volume-limited sample of M dwarfs within 12 pc. We are obtaining complete observations for this subsample, to derive unbiased multiplicity statistics for the very-low-mass disk population. Additionally, we resolve for the first time 6 known spectroscopic or astrometric binaries, for a total of 27 newly resolved companions. A fair fraction of the new binaries has favourable parameters for accurate mass determinations. The newly resolved companion of Gl 120.1C had an apparent spectroscopic minimum mass in the brown-dwarf range (Duquennoy & Mayor 1991), and it contributed to the statistical evidence that a few percent of solar type stars might have close-in brown-dwarf companions. We find that Gl 120.1C actually is an unrecognised double- lined spectroscopic pair. Its radial-velocity amplitude had therefore been strongly underestimated by Duquennoy & Mayor (1991), and it does not truly belong to their sample of single-lined systems with minimum spectroscopic mass below the substellar limit. We also present the first direct detection of Gl 494B, an astrometric brown-dwarf candidate. Its luminosity does straddle the substellar limit, and it is a brown dwarf if its age is less than �300 Myr. A few more years of observations will ascertain its mass and status from first principles.

Resource interdependence, student interactions and performance in cooperative learning

Abstract: Two studies were carried out during university workshops, and analyzed the effects of resource interdependence on student‐student interactions, and the impact of these interactions on performance. Students worked cooperatively, either on complementary information (positive resource interdependence) or on identical information (resource independence). In Study 1, analysis of videotaped interactions revealed that working on complementary information produced more positive interactions; however this was not sufficient to prevent students who had no direct access to the information from being disadvantaged, because of informational dependence. In Study 2, with simpler texts allowing better information transmission, performance was favored when students worked on complementary information. Moreover, working on identical information not only enhanced confrontations of point of views, it also elicited competence threat. Further analysis revealed that competence threat mediated resource interdependence effect on ...

Challenges in building service-oriented applications for OSGi

Abstract: The OSGi Alliance defines and promotes open specifications for the delivery of managed services into networked environments of embedded devices. A key element of this initiative is the OSGi framework, which is a lightweight framework for deploying and executing service-oriented applications. The service-oriented approach is well suited to the dynamic environment envisioned for services gateways, but it creates unique challenges for application developers.

Combination of CDF and D0 results on the W boson mass and width

Abstract: The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average MW = 80.456±0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width GammaW = 2.115±0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross sections. This combined result for the Tevatron is GammaW = 2.135±0.050 GeV. Finally, we use the measurements of the direct total W width and the leptonic branching ratio to extract the leptonic partial width Gamma(W-->enu) = 224±13 MeV.

Uniqueness for the two-dimensional Navier-Stokes equation with a measure as initial vorticity

Abstract: We show that any solution of the two-dimensional Navier-Stokes equation whose vorticity distribution is uniformly bounded in $L^1(R^2)$ for positive times is entirely determined by the trace of the vorticity at $t = 0$, which is a finite measure. When combined with previous existence results by Cottet, by Giga, Miyakawa, and Osada, and by Kato, this uniqueness property implies that the Cauchy problem for the vorticity equation in $R^2$ is globally well-posed in the space of finite measures. In particular, this provides an example of a situation where the Navier-Stokes equation is well-posed for arbitrary data in a function space that is large enough to contain the initial data of some self-similar solutions.

Cost Analysis of Human Islet Transplantation for the Treatment of Type 1 Diabetes in the Swiss-French Consortium GRAGIL

Abstract: OBJECTIVE—To evaluate the cost of islet transplantation in type 1 diabetic patients with a functional renal graft in a multicenter network RESEARCH DESIGN AND METHODS—The study involved nine diabetic patients transplanted in the Swiss-French Groupe Rhone-Alpes, Rhin et Geneve pour la transplantation d’Ilots Langerhans (GRAGIL) consortium between March 1999 and June 2000 The direct medical costs were estimated from Social Security’s perspective from the inclusion of the patient to 1 year after transplantation All cost components were computed separately and included evaluation, screening and candidacy, organ retrieval, islet processing, pancreas and islet transportation, hospitalization for transplantation, follow-up, medications (immunosuppressive, antidiabetic, and adjuvant drugs), and adverse events requiring hospitalization RESULTS—During the study period, 56 pancreata were processed and 14 islet preparations were transplanted The average cost of an islet transplantation (procedure and 1-year follow-up) was €77,745 (French rate, year 2000) The four main cost components were islet preparation (30% of the total cost), adverse events (24%), drugs (14%), and hospitalization (13%) CONCLUSIONS—Overall costs of islet transplantation are slightly higher than those of pancreas transplantation The cell isolation process is a critical point; a reduction in overall cost will require more efficient ways of isolating high yields of viable islets Costs generated by shipments within the GRAGIL network did not represent an economic burden It can be expected that the costs will decrease with growing experience and improving technology

Dynamic Quantum Logic for Quantum Programs

Abstract: We present a way to apply quantum logic to the study of quantum programs. This is made possible by using an extension of the usual propositional language in order to make transformations performed on the system appear explicitly. This way, the evolution of the system becomes part of the logical study. We show how both unitary operations and two-valued measurements can be included in this formalism and can thus be handled logically.

Impact of the cutting dynamics of small radial immersion milling operations on machined surface roughness

Abstract: This paper deals with a numerical and experimental study of the dynamics of flank milling operations at low cutting rates. It focuses on both properties of the cutting vibratory phenomena and their impacts on the roughness of the machined surface. The study is based on a one degree of freedom model of the mechanical machining system. The system is of the rigid cutter–flexible workpiece type. The cutting force model is based on the regenerative mechanism. The roughness of the surface machined at high speed revolutions has been studied for both forced vibrations occurring during stable cutting and self-excited vibrations occurring during unstable cutting. It is shown that forced vibrations have only a very slight impact (roughness remains quite similar to that obtained with a fully rigid mechanical system), while unstable cutting mainly impacts roughness. The stable milling zones can be shown on a roughness map. The study of the roughness shows that the boundary between stable and unstable cutting conditions, in the case of interrupted cutting, is a wide zone characterised by a doubling of the tooth passing period. In this zone, only one tooth over two is removing material due to the vibratory motion. A discussion explains the phenomenon.