Developing methodologies to allow the robust prediction dynamic context dominated by perturbations

El principal objectiu del projecte era desenvolupar millores conceptuals i metodològiques que permetessin una millor predicció dels canvis en la distribució de les espècies (a una escala de paisatge) derivats de canvis ambientals en un context dominat per pertorbacions. En un primer estudi, vàrem comparar l'eficàcia de diferents models dinàmics per a predir la distribució de l'hortolà (Emberiza hortulana). Els nostres resultats indiquen que un model híbrid que combini canvis en la qualitat de l'hàbitat, derivats de canvis en el paisatge, amb un model poblacional espacialment explícit és una aproximació adequada per abordar canvis en la distribució d'espècies en contextos de dinàmica ambiental elevada i una capacitat de dispersió limitada de l'espècie objectiu. En un segon estudi abordarem la calibració mitjançant dades de seguiment de models de distribució dinàmics per a 12 espècies amb preferència per hàbitats oberts. Entre les conclusions extretes destaquem: (1) la necessitat de que les dades de seguiment abarquin aquelles àrees on es produeixen els canvis de qualitat; (2) el biaix que es produeix en la estimació dels paràmetres del model d'ocupació quan la hipòtesi de canvi de paisatge o el model de qualitat d'hàbitat són incorrectes. En el darrer treball estudiarem el possible impacte en 67 espècies d’ocells de diferents règims d’incendis, definits a partir de combinacions de nivells de canvi climàtic (portant a un augment esperat de la mida i freqüència d’incendis forestals), i eficiència d’extinció per part dels bombers. Segons els resultats dels nostres models, la combinació de factors antropogènics del regim d’incendis, tals com l’abandonament rural i l’extinció, poden ser més determinants per als canvis de distribució que els efectes derivats del canvi climàtic. Els productes generats inclouen tres publicacions científiques, una pàgina web amb resultats del projecte i una llibreria per a l'entorn estadístic R.

The post-communist fertility puzzle

Fertility has unanimously declined across the entire post-communist region. This study explores the variation in fertility trends over time among these countries and assesses to what degree three explanations are applicable: second demographic transition (SDT), postponement transition (PPT) or reaction to the economic crisis. Moreover, on the basis of SDT and PPT theoretical tenets, as well as descriptive evidence, the economic context is hypothesized to be linked to two processes of fertility decline conversely. The results show that no one theoretical explanation is sufficient to explain the complex fertility declines across the entire post-communist region from 1990 to 2003. In some countries, a great part of the decline in fertility occurred before significant postponement of childbearing began, which indicates that the dramatic decline was due to stopping behavior or postponement of higher order births. Postponement of first births, either through PPT or SDT processes, greatly contributed to fertility decline in a small number of countries. Pooled cross-sectional time-series analyses of age-specific birthrates confirm that these two distinct processes are present and show that the economic crisis explanation has explanatory power for declining birth rates. In contrast, logistic regressions show that the likelihood of postponing childbirth increases with improved economic conditions. These results confirm the importance of taking the economic context into account when discussing explanations for fertility decline. More specifically, the results indicate that the severity and duration of economic crisis, or absence thereof, influenced the extent and manner in which fertility declined.

Assembling genes from predicted exons in linear time with dynamic programming

In a number of programs for gene structure prediction in higher eukaryotic genomic sequences, exon prediction is decoupled from gene assembly: a large pool of candidate exons is predicted and scored from features located in the query DNA sequence, and candidate genes are assembled from such a pool as sequences of nonoverlapping frame-compatible exons. Genes are scored as a function of the scores of the assembled exons, and the highest scoring candidate gene is assumed to be the most likely gene encoded by the query DNA sequence. Considering additive gene scoring functions, currently available algorithms to determine such a highest scoring candidate gene run in time proportional to the square of the number of predicted exons. Here, we present an algorithm whose running time grows only linearly with the size of the set of predicted exons. Polynomial algorithms rely on the fact that, while scanning the set of predicted exons, the highest scoring gene ending in a given exon can be obtained by appending the exon to the highest scoring among the highest scoring genes ending at each compatible preceding exon. The algorithm here relies on the simple fact that such highest scoring gene can be stored and updated. This requires scanning the set of predicted exons simultaneously by increasing acceptor and donor position. On the other hand, the algorithm described here does not assume an underlying gene structure model. Indeed, the definition of valid gene structures is externally defined in the so-called Gene Model. The Gene Model specifies simply which gene features are allowed immediately upstream which other gene features in valid gene structures. This allows for great flexibility in formulating the gene identification problem. In particular it allows for multiple-gene two-strand predictions and for considering gene features other than coding exons (such as promoter elements) in valid gene structures.

Une approche causale des comportements d'achat et post-achat de produits écolabellisés

RESUMÉ Objectifs de la recherche: Depuis quelques années, l'utilisation de l'écologie dans le marketing a connu un essor considérable, aussi bien dans le monde académique que dans la pratique. De nos jours, la notion de label suscite un vif intérêt auprès des entreprises désireuses de promouvoir des produits "verts". Le principe de l'écolabellisation consiste à fournir aux consommateurs, en plus du prix, un nouvel élément de comparaison des produits. Les écolabels sont considérés comme l'un des meilleurs outils pour informer le consommateur, d'une manière claire et compréhensible, de l'impact du produit sur l'environnement. Nous nous intéressons, dans le cadre de notre travail, à l'étude du comportement d'achat des produits écolabellisés. En dépit de leur popularité croissante, les études académiques portant sur les labels écologiques sont relativement rares et de nombreuses problématiques demeurent en suspens. L'étude du comportement d'achat - au sens large - mérite notamment d'être approfondie. Notre recherche a plusieurs volets. Premièrement, nous étudions l'impact des valeurs, de l'implication vis-à-vis de l'écologie, du scepticisme, de la compréhension du label et de la connaissance de l'écologie sur le comportement d'achat de produits écolabellisés. Ensuite, nous testons la cohérence entre comportements écologiques en introduisant un comportement post- achat (le triage des déchets ménagers). Théories sous-jacentes: Notre étude repose sur différents apports académiques relatifs au comportement du consommateur "vert" mais également sur des concepts issus de la psychologie et de la sociologie. Nous présentons d'abord la littérature portant sur la caractérisation du consommateur "vert" (Webster, 1975; Arbuthnot, 1977; Van Liere et Dunlap, 1981; Balderjahn, 1988; Antil, 1984; Grunert et Juhl, 1995; Roberts, 1996). Nous abordons ensuite les études portant sur les valeurs (Schwartz, 1992; 1994), l'implication (Zaichkowsy, 1994), le scepticisme (Gray-Lee, Scammon et Mayer, 1994; Mohr et al., 1998), la compréhension des écolabels (van Dam et Reuvekamp, 1995; Thogersen, 2000) et la connaissance de l'écologie (Maloney et al., 1973, 1975; Arbuthnot, 1977; Pickett et al., 1993). Ces variables nous semblent être les plus à même d'influencer le comportement d'achat de produits écolabellisés. Enfin, sur la base des travaux de Valette-Florence et Roehrich (1993), nous développons un modèle de causalité, centré sur la relation entre les valeurs, l'implication et le comportement. Hypothèses de recherche et opérationnalisation des variables: Nous développons 16 hypothèses de recherche dont 12 portent sur les rapports de causalité entre construits. Par ailleurs, pour mieux comprendre la personnalité du consommateur de produits écolabellisés, nous distinguons les variables reflétant un intérêt collectif (altruisme) de celles reflétant un intérêt individuel (égocentrisme). La mesure des différents construits reposent sur la liste de Schwartz (1992, 1994) pour les valeurs, l'échelle d'implication de Zaichkowsy (1994) pour la publicité, l'échelle développée par Mohs et al. (1998) pour mesurer le scepticisme et une liste de questions portant sur l'écologie (Diekmann, 1996) pour tester le niveau de connaissance. Les comportements d'achat et post-achat sont mesurés respectivement à l'aide de questions relatives à la fréquence d'achat de produits écolabellisés et du triage des déchets ménagers. Collecte des données: Le recueil des données s'effectue par sondage, en ayant recours à des questionnaires auto-administrés. L'échantillon comprend de 368 étudiants provenant de diverses facultés de sciences humaines de Suisse Romande. Analyse des données et interprétation des résultats: Notre étude porte sur le comportement d'achat de trois labels écologiques et sur le triage de 7 déchets ménagers. Les différentes analyses montrent que certaines valeurs ont un impact sur l'implication et que l'implication a une influence positive sur le comportement d'achat et post-achat. Par ailleurs, nous montrons que l'implication sert de variable médiatrice entre les valeurs et le comportement. De plus, la compréhension de l'écolabel influence de manière positive l'achat de produits écolabellisés, la connaissance de l'écologie a une influence positive sur le comportement post-achat et le scepticisme vis-à-vis de l'utilité du triage des déchets ménagers influence négativement le comportement de triage. Implications managériales: Les résultats obtenus suggèrent qu'outre la valeur "protection de l'environnement", d'autres valeurs comme "la stimulation" ou encore "l'accomplissement" influencent de manière significative l'implication vis-à-vis de l'écologie qui à son tour influence l'achat de produits écolabellisés. Le manager doit donc tenir compte du fait que le consommateur est impliqué dans l'écologie. Ensuite, la compréhension du label joue un rôle prépondérant dans l'achat. De plus, le consommateur ne semble pas être sceptique par rapport aux informations fournies par les écolabels et le niveau de connaissance de l'écologie n'affecte pas son comportement. Enfin, le consommateur semble agir de manière cohérente en achetant différents produits écolabellisés. Apports, limites et voies de recherche: Notre étude contribue à l'enrichissement de la recherche sur le comportement du consommateur dans un contexte écologique à plusieurs égards, notamment par l'étude de la relation entre les valeurs, l'implication et le comportement. Néanmoins, la portée de notre recherche est naturellement restreinte en raison du nombre limité de cas étudiés, soit 3 labels écologiques relativement peu connus de notre échantillon. Il serait utile de répéter l'étude en utilisant des labels plus populaires. Par ailleurs, nous avons eu recours à des échelles développées dans des contextes quelque peu différents. En particulier, une échelle d'implication devrait être développée spécifiquement pour le contexte écologique.

Validation française d'un questionnaire de stress post-traumatique destiné aux parents d'enfants présentant un risque périnatal élevé = French validation of the "Perinatal PTSD Questionnaire" assessing parent's posttraumatic stress reactions following the birth of a high risk infant.

(from the journal abstract) Objectives: The birth of a high risk infant--such as a very or extremely premature infant--can represent an important traumatic experience for parents. R. DeMier, M. Hynan et al's "Perinatal PTSD Questionnaire" aims at exploring, retrospectively, parent's posttraumatic stress reactions following the birth of a high risk infant. This paper describes the French validation of this questionnaire. Methods: Fifty-two families with a very or extremely premature infant and 25 families with a full term infant responded to the "Perinatal PTSD Questionnaire" and the "Impact of Event Scale" when children were 18 months old. Results: Parents of high risk infants can present posttraumatic stress reactions such as intrusion, avoidance or arousal symptoms. The French version of the "Perinatal PTSD Questionnaire" has satisfactory psychometric properties. Conclusions: As posttraumatic reactions are not directly related to objective descriptions of the stressful event, it may be essential to the liaison child psychiatrist to consider individual posttraumatic reactions in order to optimise preventive intervention with the parents. A questionnaire should not replace a clinical interview, however it may represent a useful screening tool. Also, this questionnaire should be useful for research purposes. (PsycINFO Database Record (c) 2005 APA, all rights reserved)

Dynamic estimation of three-dimensional cerebrovascular deformation from rotational angiography

Purpose: The objective of this study is to investigate the feasibility of detecting and quantifying 3D cerebrovascular wall motion from a single 3D rotational x-ray angiography (3DRA) acquisition within a clinically acceptable time and computing from the estimated motion field for the further biomechanical modeling of the cerebrovascular wall. Methods: The whole motion cycle of the cerebral vasculature is modeled using a 4D B-spline transformation, which is estimated from a 4D to 2D + t image registration framework. The registration is performed by optimizing a single similarity metric between the entire 2D + t measured projection sequence and the corresponding forward projections of the deformed volume at their exact time instants. The joint use of two acceleration strategies, together with their implementation on graphics processing units, is also proposed so as to reach computation times close to clinical requirements. For further characterizing vessel wall properties, an approximation of the wall thickness changes is obtained through a strain calculation. Results: Evaluation on in silico and in vitro pulsating phantom aneurysms demonstrated an accurate estimation of wall motion curves. In general, the error was below 10% of the maximum pulsation, even in the situation when substantial inhomogeneous intensity pattern was present. Experiments on in vivo data provided realistic aneurysm and vessel wall motion estimates, whereas in regions where motion was neither visible nor anatomically possible, no motion was detected. The use of the acceleration strategies enabled completing the estimation process for one entire cycle in 5-10 min without degrading the overall performance. The strain map extracted from our motion estimation provided a realistic deformation measure of the vessel wall. Conclusions: The authors' technique has demonstrated that it can provide accurate and robust 4D estimates of cerebrovascular wall motion within a clinically acceptable time, although it has to be applied to a larger patient population prior to possible wide application to routine endovascular procedures. In particular, for the first time, this feasibility study has shown that in vivo cerebrovascular motion can be obtained intraprocedurally from a 3DRA acquisition. Results have also shown the potential of performing strain analysis using this imaging modality, thus making possible for the future modeling of biomechanical properties of the vascular wall.

CO2 production of the chick embryo during the first day of post-laying development.

The carbon dioxide production of the chick embryo cultured in vitro has been determined during the first 24 h of post-laying development using a non-invasive conductometric microtechnique. The mean CO2 production of the whole blastoderm (1) increased from 16 nmol/h at laying to 231 nmol/h at early neurulation, (2) became dependent on exogenous glucose and (3) was closely linked to mechanical tension generated in the blastoderm (loosening from vitelline membrane resulted in a decrease of 56%). In our experimental conditions, no significant influence of carbonic anhydrase on the CO2 production has been detected. The value of the respiratory exchange ratio varied from about 3 at pregastrular stages to 1 at neurula stage and CO2 was produced transiently in presence of antimycin A. Such results indicate that the source of CO2 is not exclusively mitochondrial and that the relative proportions of mitochondrial and non-mitochondrial CO2 productions might vary significantly throughout the early development. Our findings confirm that the metabolism of the chick embryo becomes more and more oxidative from laying onwards and suggest that the modifications of metabolism observed during the studied period of development could be associated with functional differentiation.

Multiuser detection in a dynamic environment — Part II: Joint user identification and parameter estimation

The problem of jointly estimating the number, the identities, and the data of active users in a time-varying multiuser environment was examined in a companion paper (IEEE Trans. Information Theory, vol. 53, no. 9, September 2007), at whose core was the use of the theory of finite random sets on countable spaces. Here we extend that theory to encompass the more general problem of estimating unknown continuous parameters of the active-user signals. This problem is solved here by applying the theory of random finite sets constructed on hybrid spaces. We doso deriving Bayesian recursions that describe the evolution withtime of a posteriori densities of the unknown parameters and data.Unlike in the above cited paper, wherein one could evaluate theexact multiuser set posterior density, here the continuous-parameter Bayesian recursions do not admit closed-form expressions. To circumvent this difficulty, we develop numerical approximationsfor the receivers that are based on Sequential Monte Carlo (SMC)methods (“particle filtering”). Simulation results, referring to acode-divisin multiple-access (CDMA) system, are presented toillustrate the theory.

Contribution pollinique à l'étude du pléistocène de la région lémanique (Suisse) : paléoenvironnement des derniers 800'000 ans

Abstact : Pollinic contribution to a Pleistocene study of the Lake Geneva region (Switzerland) Palaeoenvironment of the last 800,000 years. Although the "Plateau Romand" (tableland of French-speaking Switzerland) has been marked by the repetitive action of different Quaternary glacial thrusts, numerous preserved outcrops here and there, thanks to favourable topographical conditions, provide sufficient pollinic content to reconstitute the significant botanical fluctuations and allow bio- and chrono-stratigraphical correlations with the long European sequences. The present study examines around ten Pleistocene deposits rich in pollens, whose presumed ages cover a range of 800,000 years. - The Early and Early-Middle Pleistocene are examined at Ecoteaux (VD), undeniably the oldest site in this study. The "Lower Formation of Ecoteaux", whose low pollinic content reveals an environment of the cold desert type, shows an inverse palaeomagnetic remanence. An age earlier than 780,000 years BP (Matuyama period or earlier) is proposed. The "Upper Formation of Ecoteaux" contains over eight major fluctuations in the vegetal covering, of which at least four temporal phases and one climatic optimum. The presence of botanical genera, relics of the Tertiary in particular Pterocarya and Carya, associated with the vegetal dynamic made up of short oscillations, contrives to link this formation to the Cromerian Complex. The thermomeres recorded could correspond to one or several interglacial periods from Middle Pleistocene. Possible correlations with marine isotopic stages 15, 17 and 19 are discussed. - The Middle and Late Pleistocene is approached through the sediments of Onnens (VD), Creux d'Enfer (FR), Port-Valais (VS), La Dénériaz (VD) and Cortaillod (NE). Each site provides a temperate interglacial flora, whose pollinic content is evaluated according to the different conceivable bio-stratigraphic correlations. - Finally the Würm is studied thanks to the outcrop of Marly (FR), together with the excavations at Villars-sous-Yens (VD), Versoix (GE) and Ollon (VD). Together, these observations tend to show that the west of the Swiss Plateau is a zone of transition between the meridian vegetation of the lower Rhone valley and that of beyond the Jura. At the outlet of the Rhone glacier, and on the borders of the prealpine and Jurassian glaciers, the region is situated at the crossroads of post-glacial botanical migrations, between the major axis of the Rhone valley and the Eastern refuge zones; this situation confers particular importance on it. Although believed to be deeply scraped by ice, one notices today that the "Plateau Romand" harbours overtwenty interglacial and interstadial sites. The abrasive action of the Rhone glacier has thus been more modest than previously estimated. The effective extension of glacial tongues, together with atmospheric circulation, are doubtless varying from one interglacial to another. Finally, the speeds of glacial movements, and the unbelievable vegetal vitality, are important parameters, capable of leading to deposits, very early enriched in pollens. RÉSUMÉS : Contribution pollinique à l'étude du Pléistocène de la région lémanique (Suisse) - Paléoenvironnement des derniers 800'000 ans Bien que le Plateau romand soit marqué par l'action répétitive des différentes poussées glaciaires quaternaires, de nombreux affleurements préservés ça et là, à la faveur de conditions topographiques favorables, livrent un contenu pollinique suffisant pour reconstituer des fluctuations botaniques significatives et autoriser des corrélations bioet chronostratigraphiques avec les longues séquences européennes. Le présent travail étudie une dizaine de dépôts pléistocènes riches en pollens, dont les âges présumés balaient un éventail de plus de 800'000 ans. - Le Pléistocène Ancien et Moyen inférieur, sont examinés à Ecoteaux (VD); indéniablement le site le plus ancien de cette étude. La "Formation inférieure d'Ecoteaux", dont le maigre contenu pollinique traduit un environnement de type désertique froid, présente une rémanence magnétique inverse. Un âge antérieur à 780'000 ans BP (période de Matuyama ou antérieure) est proposé. La "Formation supérieure d'Ecoteaux" comprend plus de huit fluctuations majeures du couvert végétal, parmi lesquelles on compte au moins quatre épisodes tempérés et un optimum climatique. La présence de genres botaniques reliques du Tertiaire, en particulier Pterocarya et Carya, associée à la dynamique végétale faite de courtes oscillations, concourent à lier cette formation au Complexe Cromérien. Les thermomères enregistrées pourraient correspondre à un- ou plusieurs interglaciaires du Pléistocène moyen. Les corrélations possibles avec les stades isotopiques marins, MIS 15, 17 et 19 sont discutées. - Le Pléistocène Moyen et Récent est abordé à travers les sédiments d'Onnens (VD), du Creux d'Enfer (FR), de Port-Valais (VS), de La Dénériaz (VD) et de Cortaillod (NE). Chaque site livre une flore tempérée interglaciaire, dont le contenu pollinique est évalué en fonction des différentes corrélations bio-stratigraphiques envisageables. - Enfin le Würm est étudié grâce à l'affleurement de Marly (FR), accompagné des forages de Villars-sous-Yens (VD), Versoix (GE) et Ollon (VD). L'ensemble de ces observations tend à montrer que l'ouest du Plateau suisse est une zone charnière entre la végétation méridionale de la basse vallée du Rhône et celle d'au-delà du Jura. Au débouché du glacier du Rhône et aux confins des glaciers préalpins et jurassiens, cette région est située au carrefour des migrations botaniques post-glaciaires, entre l'axe majeur de la vallée du Rhône et les zones refuges de l'Est. Cette situation lui confère une importance toute particulière. Alors qu'on pensait le Plateau romand profondément raboté par les glaces, on constate aujourd'hui qu'il recèle plus d'une vingtaine de sites interglaciaires et interstadiaires. L'action abrasive du glacier rhodanien a donc été plus modeste qu'envisagée jusqu'ici. L'extension effective des langues glaciaires, tout comme la circulation atmosphérique, diffèrent sans doute d'un interglaciaire à l'autre. Enfin la vitesse des mouvements glaciaires et l'incroyable vitalité végétale sont des paramètres importants, susceptibles d'avoir entraîné des dépôts, très précocement enrichis en pollens.

Stochastic Dynamic Northern Corn Rootworm Population Model, January 2000

A complete life cycle model for northern corn rootworm, Diabrotica barberi Smith and Lawrence, is developed using a published single-season model of adult population dynamics and data from field experiments. Temperature-dependent development and age-dependent advancement determine adult population dynamics and oviposition, while a simple stochastic hatch and density-dependent larval survival model determine adult emergence. Dispersal is not modeled. To evaluate the long-run performance of the model, stochastically generated daily air and soil temperatures are used for 100-year simulations for a variety of corn planting and flowering dates in Ithaca, NY, and Brookings, SD. Once the model is corrected for a bias in oviposition, model predictions for both locations are consistent with anecdotal field data. Extinctions still occur, but these may be consistent with northern corn rootworm metapopulation dynamics.

Large-system analysis of a CDMA dynamic channel under a Markovian input process

We study the minimum mean square error (MMSE) and the multiuser efficiency η of large dynamic multiple access communication systems in which optimal multiuser detection is performed at the receiver as the number and the identities of active users is allowed to change at each transmission time. The system dynamics are ruled by a Markov model describing the evolution of the channel occupancy and a large-system analysis is performed when the number of observations grow large. Starting on the equivalent scalar channel and the fixed-point equation tying multiuser efficiency and MMSE, we extend it to the case of a dynamic channel, and derive lower and upper bounds for the MMSE (and, thus, for η as well) holding true in the limit of large signal–to–noise ratios and increasingly large observation time T.

Chimioradiothérapie postopératoire des cancers des voies aérodigestives : vers un nouveau standard [Post-operative radiochemotherapy of the head and neck: Towards new standards?]

Head and neck squamous cell carcinomas are frequently diagnosed at an advanced stage. Their treatment remains controversial, and has to be multidisciplinary. External beam radiotherapy is a recognized treatment option after radical curative surgery in order to improve local control. Different adjuvant treatment options have been studied in order to improve the outcome of these patients. We review in this paper the different prognostic factors indicating an adjuvant treatment and the interest of treatment intensification in bad prognostic patients.

Teaching motivational interviewing to medical students : a pre-post test pilot study

Objective: To test the efficacy of teaching motivational interviewing (MI) to medical students. Methods: Thirteen 4th year medical students volunteered to participate. Seven days before and 7 days after an 8-hour interactive training MI workshop, each student performed a videorecorded interview with two standardized patients: a 60 year old alcohol dependent woman and a 50 year old cigarette smoking man. Students' counseling skills were coded by two blinded clinicians using the Motivational Interviewing Treatment Integrity 3.0 (MITI). Inter-rater reliability was calculated for all interviews and a test-retest was completed in a sub-sample of 10 consecutive interviews three days apart. Difference between MITI scores before and after training were calculated and tested using non-parametric tests. Effect size was approximated by calculating the probability that posttest scores are greater than pretest scores (P*=P(Pre<Post)+1/2P(Pre=Post)), P*>1/2 indicating greater scores in posttest, P*=1/2 no effect, and P*<1/2 smaller scores in posttest. Results: Median differences between MITI scores before and after MI training indicated a general progression in MI skills: MI spirit global score (median difference=1.5, Inter quartile range=1.5, p<0.001, P*=0.90); Empathy global score (med diff=1, IQR=0.5, p<0.001, P*=0.85); Percentage of MI adherent skills (med diff=36.6, IQR=50.5, p<0.001, P*=0.85); Percentage of open questions (med diff=18.6, IQR=21.6, p<0.001, P*=0.96); reflections/ questions ratio (med diff=0.2, IQR=0.4, p<0.001, P*=0.81). Only Direction global score and the percentage of complex reflections were not significantly improved (med diff=0, IQR=1, p=0.53, P*=0.44, and med diff=4.3, IQR=24.8, p=0.48, P*=0.62, respectively). Inter-rater reliability indicated weighted kappa ranged between 0.14 for Direction to 0.51 for Collaboration and ICC ranged between 0.28 for Simple reflection to 0.95 for Closed question. Test-retests indicated weighted kappa ranged between 0.27 for Direction to 0.80 for Empathy and ICC ranged between 0.87 for Complex reflection to 0.98 for Closed question. Conclusion: This pilot study indicated that an 8-hour training in MI for voluntary 4th year medical students resulted in significant improvement of MI skills. Larger sample of unselected medical students should be studied to generalize the benefit of MI training to medical students. Interrater reliability and test-retests suggested that coders' training should be intensified.