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9th International Conference on Predictive Modelling in Food (ICPMF); Rio de Janeiro, BRAZIL; The inhibitory effect of water activity (a(w)) and storage temperature on single spore lag times of Aspergillus niger, Eurotium repens (Aspergillus pseudoglaucus) and Penicillium corylophilum strains isolated from spoiled bakery products, was quantified. A full factorial design was set up for each strain. Data were collected at levels of a(w) varying from 0.80 to 0.98 and temperature from 15 to 35 degrees C. Experiments were performed on malt agar, at pH 5.5. When growth was observed, ca 20 individual growth kinetics per condition were recorded up to 35 days. Radius of the colony vs time was then fitted with the Buchanan primary model. For each experimental condition, a lag time variability was observed, it was characterized by its mean, standard deviation (sd) and 5th percentile, after a Normal distribution fit. As the environmental conditions became stressful ( e.g. storage temperature and a(w) lower), mean and sd of single spore lag time distribution increased, indicating longer lag times and higher variability. The relationship between mean and sd followed a monotonous but not linear pattern, identical whatever the species. Next, secondary models were deployed to estimate the cardinal values (minimal, optimal and maximal temperatures, minimal water activity where no growth is observed anymore) for the three species. That enabled to confirm the observation made based on raw data analysis: concerning the temperature effect, A. niger behaviour was significantly different from E. repens and P. corylophilum: Tops of 37.4 degrees C (standard deviation 1.4 degrees C) instead of 27.1 degrees C (1.4 degrees C) and 25.2 degrees C (1.2 degrees C), respectively. Concerning the a(w) effect, from the three mould species, E. repens was the species able to grow at the lowest a(w) (aw(min), estimated to 0.74 (0.02)). Finally, results obtained with single spores were compared to findings from a previous study carried out at the population level (Dagnas et al., 2014). For short lag times days), there was no difference between lag time of the population (ca 2000 spores inoculated in one spot) and mean (nor 5th percentile) of single spore lag time distribution. In contrast, when lag time was longer, i.e. under more stressful conditions, there was a discrepancy between individual and population lag times (population lag times shorter than 5th percentiles of single spore lag time distribution), confirming a stochastic process. Finally, the temperature cardinal values estimated with single spores were found to be similar to those obtained at the population level, whatever the species. All these findings will be used to describe better mould spore lag time variability and then to predict more accurately bakery product shelf-life.

Variability in germination under extreme temperatures of two perennial pasture legumes. 26. General meeting of the European Grassland Federation (EGF)

أصبح المشرق خلال القرن الاول قبل الميلاد، مع صعود الامبراطورية الرومانية، مسرحاً عالمياً تتفاعل فيه ثقافات مختلفة. ثقافات لطالما ميزت المشرق بسبب الغزوات واختلاط الشعوب منذ العصر الحجري الحديث. النظام العالمي الجديد جعل روما "عاصمة العالم" أو كما يقال باللاتينية Caput Mundi وبذلك رسم الجيش الروماني الطرق الى مختلف أصقاع الامبراطورية لتؤدي الى روما. كشفت الحفريات الوقائية و الإنقاذية الأخيرة في بيروت والبترون عن معطيات جديدة تخص الشعوب التي عاشت في المنطقة خلال القرون الأربعة من الإمبراطورية الرومانية وحتى بدايات المسيحية. تقدم رسالة الدكتوراه هذه دراسة عن الإنسان وعلاقاته مع الموت. وباتباع منهج أثري-أنثروبولوجي ستقدم تقييماً لثمان مواقع مدفنية في كولونيا جوليا أوغوستا فيليكس بيريتوس Colonia Julia Augusta Felix Berytus ومدينة البترون (ع=٢٩٠ ) والتي على عكس بيريتوس )بيروت) لم تحمل صفة مستوطنة رومانية .تقدم هذه الدراسة في المقام الأول الاطار الثقافي والبيولوجي والمشروحين بتعدد الطقوس المدفنية والاختلاف البيولوجي لمجموعتين او اكثر من المجموعات التي تعيش في كولونيا جوليا أوغوستا فيليكس بيريتوس. في المقابل المعطيات البيولوجية الثقافية في البترون تدل على أنها مدينة أقل تنوعاً ولا تحوي تنوعات انثروبولوجية وثقافية كبيرة. لذلك فإن التطابق في طرق الدفن وتحضير الموتى وأمكنة الدفن والتجانس البيولوجي هي مسائل لاجدال فيها بالنسبة للبترون. وبالمقارنة مابين بيروت والبترون من الواضح عدم التجانس البيولوجي الموجود على أكثر من صعيد فيما بين سكان المدينتين.ولكن هذا التباين مابين المدينتين مخترق من قبل تشابه الإناث في كلا المدينتين من القرن الثاني الى القرن الرابع ميلادي.; During the first century B.C., with the rise of the Roman Empire, the Levant became the scene of cosmopolitanism where many heteroclite cultures would coexist. The new cosmopolitan society had Rome as its capital (Caput Mundi), and roads drawn up by the army linking the rest of the empire to its capital. Recent rescue excavations (since 2005) in Berytus (Beirut) and Botrys (Batroun) have revealed a considerable amount of unpublished data on populations who lived in the region during the four centuries of the Roman Empire until the early centuries of Christianity. Following an archaeo-anthropological approach, this thesis presents an assessment of eight funerary sites (n= 290) from the cities of Colonia Julia Augusta Felix Berytus and Botrys. Significantly, Botrys, unlike Berytus, did not have the status of a Roman colony. This research seeks to contribute to the history of these two cities. The purpose is to understand the populations of the past through the study of the skeletons, rituals and funerary practices as well as the organisation of funerary spaces. This study primarily reveals a cultural and biological cosmopolitanism illustrated by variability in funerary practices and in biological characteristics. These results suggest that at least two different groups or more coexisted in the Colonia Julia Augusta Felix Berytus. On the contrary, the biocultural data of Botrys skeletons reveal a less cosmopolitan city with less diversity shown on different anthropological and cultural levels. Indeed, the similarity of funerary practices, body treatments, grave goods and the organisation of the funerary space and biological homogeneity are indisputable in Botrys. Comparative analysis between Berytus and Botrys highlighted an existing biological heterogeneity at different scales between individuals of both cities. However, this diversity is contradicted by the homogeneity of the females of both cities during the 2th and the 4th century A. D.; Avec l’avènement de l’Empire romain au cours du premier siècle avant notre ère le Levant devient le théâtre d’un cosmopolitisme où maintes cultures hétéroclites vont coexister. Ce nouveau système a Rome comme Caput Mundi. Des voies vont être tracées par l’armée jusqu’au fin fond de l’empire pour relier le monde à sa capitale. Les fouilles préventives récentes (depuis 2005) à Berytus (Beyrouth) et à Botrys (Batroun) ont mis au jour une quantité considérable de données inédites sur l’homme et sur les populations qui vivaient dans la région durant les quatre siècles de l’Empire romain et jusqu’au début du Christianisme. À partir d’une étude archéo‐anthropologique de huit ensembles funéraires (n=290) provenant de la Colonia Julia Augusta Felix Berytus et de la ville de Botrys qui contrairement à Berytus n’a pas le statut de colonia romana, ce travail propose de contribuer à l’histoire de ces deux villes. Notre but est d’appréhender les populations du passé d’après l’étude du squelette, les caractéristiques biologiques, les rituels et les pratiques funéraires ainsi que l’organisation des espaces sépulcraux. Cette étude révèle en premier lieu un cosmopolitisme culturel et biologique illustré par la variabilité des pratiques funéraires et par la diversité biologique des deux ou plusieurs groupes qui ont dû coexister à la Colonia Julia Augusta Felix Berytus. Par contre, les données bio-culturelles de Botrys évoquent quant à elles, une cité moins cosmopolite, moins diversifiée sur les plans anthropologiques et culturels. En effet, la ressemblance des modes d’inhumation, du traitement du corps, du mobilier funéraire et la structuration de l’espace funéraire et l’homogénéité biologique sont incontestables à Botrys. En revanche, les analyses comparatives entre Berytus et Botrys ont mis en évidence une hétérogénéité biologique existante à plusieurs échelles entre les individus des deux villes. Cependant cette distance est brisée par l’homogénéité du corpus féminin des deux villes pour la période qui s'étend du IIème au IVème siècle de notre ère.

Grey mould caused by the fungus Botrytis cinerea is an economically important disease in numerous crops. Biocontrol is a promising method to control the disease. Species of Streptomyces are potential biological control agents since they are ubiquitous in the environment and many of them produce various secondary metabolites with diverse biological activities including the ability to inhibit this plant pathogenic fungus. Strains RM-1-138 and RL-1-178 of S. philanthi and SS-2-243 of S. mycarofaciens, isolated from the rhizosphere soil of chili peppers grown in southern Thailand, have shown a good efficacy to control Sclerotium roljsii, Ralstonia solanacearum and Rhizoctonia solani but their effect against B. cinerea is not known. In this study we evaluated the efficacy of the three strains of Streptomyces spp. against B. cinerea in vitro and on tomato plants. Results indicated that the three strains inhibit the growth of B. cinerea in Petri plates and have a significant protective efficacy, although variable between strains of Streptomyces spp., against B. cinerea on tomato plant. To assess the possible variability in susceptibility to these antagonistic strains in populations of B. cinerea, the protective efficacy of these bacteria were evaluated against 41 strains differing in their geographic origin, host of isolation and level of aggressiveness. Results based on confrontation tests in Petri plates suggest a diversity in the sensitivity of the different strains of B. cinerea to these biological control agents. The relevance of these results to ensure durability of the efficacy of these biological control agents will be discussed.

Various biological methods, mainly based on the utilization of antagonistic microorganisms or plant extracts, have been studied to control powdery mildews. The hyperparasite fungus Ampelomyces quisqualis (AQ-10, De Sangosse) is registered in many countries to control powdery mildew on various crops, including Oidium neolycopersici on tomato in France. A plant extract from orange (Prev-Am, Vivagro) is registered to control powdery mildew and whitefly on various crops but its effect on tomato powdery mildew is not clearly established. Spray of soluble carbohydrates on leaves of various plant species proved to have an effect against sorne plant pests but their effect against plant pathogens is not well known, except for trehalose against powdery mildew of wheat. The objectives of this study were (i) to test the effect of spraying low concentration of sugars (glucose, fructose, sucrose, trehalose) on leaves of tomato against O. neolycopersici in controlled conditions and (2) to evaluate the effect of sucrose, AQ-10 and Prev-Am separately and in combinations in semi­ commercial tunnel conditions. Results revealed that spray of sugars on tomato leaves have no significant effect against powdery mildew in controlled conditions. In tunnels, the plant extract Prev-am showed a significant effect against Oidium neolycopersici on tomato. Combination of products did not enhance the efficacy of a single product. The relevance of these results to ensure the control of powdery mildew on tomato without fungicides will be discussed.

The preventive use of resistance inducers has been shown to be an interesting method to reduce dependency on pesticides for plant protection. However, little is known on possible differences in the protective effects of such methods for different varieties of a given crop. In the present study, we assessed the effect of three compounds (acibenzolar-S-méthyl, a calcium-based mineral compound and a yeast extract) for the protection of six varieties of lettuce against two major pathogens, Sclerotinia sclerotiorum and Botrytis cinerea. The compounds were sprayed on the plants three days before inoculation. A water spray was used as a control. The protective effect of the compounds was then assessed by comparing the size of lesions developing on inoculated leaves. For both pathogens, none of the compounds fully inhibited disease development. However, reduction in lesion size was observed on some of the leaves. The effect of the three compounds was different for the two pathogens. For tests with B. cinerea, effects of plant treatment were not statistically significant. In contrast, significant effects were found for five of the varieties inoculated with S. sclerotiorum. Overall, the yeast extract provided the highest level of protection against that pathogen. However, for all compounds, the extent of the protective effect depended on the variety. Furthermore, in some cases the effect of the compound was opposite to that desired and disease was more severe on treated plants than on the water control. Possible consequences for field application of such methods will be discussed.

Consumer perception and industrial processing of fleshy fruits greatly depend on the morphology and spatial organization of cells within the tissues. To study the relations between the structure and the mechanical properties of fleshy fruits, it is necessary to quantify their cellular morphology. A generic approach is proposed to build cartographies of cellular morphology at the fruit scale, depicting regions corresponding to different cell morphologies. The approach is based on sampling the whole fruit at known positions, imaging and quantifying the local cellular morphology, pooling measurements to take into account the biological variability and projecting results in a 3D model of the whole fruit. The result is a synthetic representation of cell morphology variations within the whole fruit. Tomato pericarp was used as a model for fleshy fruits. Two different scales were investigated through 3D imaging using confocal microscopy, and macroscopy imaging of pericarp slices. The morphology of the tomato pericarp was assessed (1) from 3D microscopy images through stereological estimation of cell wall surface area and (2) from greyscale granulometry computed with mathematical morphology. Spatial heterogeneity within pericarp was described by measuring the morphology for different regions of interest within the whole fruit and for each characterisation method. This resulted in cartography of the cellular structure at the scale of the fruit; either by cell wall surface area estimate or by grey level mean size. Both methods presented complementary results, and made it possible to compare results obtained at different scales.

L'obésité est universellement définie à partir de la classification recommandée par l'Organisation mondiale de la santé (OMS), basée sur l'indice de masse corporelle (IMC). Cependant, l'application d'une norme unique présente des limites, notamment au regard de la grande variabilité interpopulationnelle, tant au niveau biologique que culturel. La relation entre l'IMC et la proportion de masse grasse corporelle, et donc avec les risques sanitaires associés, présente en effet une grande diversité entre groupes humains. La perception sociale du corps corpulent est quant à elle tout autant variable d'une culture à l'autre.

In biomechanics and in traumatology, studying injury mechanisms is essential to assess the limits of the human body. In these fields, the numerical simulation takes a leading place with finite element models that are more and more precise and realistic. Nevertheless its implementation is complex: the current models can not describe the damage and fracture properties of the living tissues. Therefore, their description of the injury mechanisms restricted their applications. In addition, these models are essentially “bioreliable” for their geometric and structural descriptions of the different organs and tissues. Therefore, the aim of this work is to improve the description of the injury mechanisms of bones and to study the way to adapt the mechanical properties to the biological variability. First, the mechanical behaviour of bones and a set of behaviour laws are studied. Then, the most appropriate law is chosen. It is validated from a thermodynamic point of view in order to adapt it to finite element method. The law is implemented in a numerical platform for dynamic explicit computation. To create this platform, some choices are to be made because of the specific dynamic explicit theory. In order to take the biological variability into account, some parameters like densities, porosity, mineral content, age or gender that influence mechanical properties are studied. Some experiental three-point bending tests are also performed on long bones. Their aims are: to study how the experimental and biological parameters could influence the femur and tibia behaviour; to model these tests to value the chosen damageable law. The valuation of the law is multilevel (from specimens to whole bones).The chosen damageable law give results in good agreement with experimental data and show a coherent fracture profil, En biomécanique des chocs et en traumatologie virtuelle, l'étude des mécanismes lésionnels est essentielle pour évaluer les seuils de tolérance du corps humain. Dans ces domaines, la simulation numérique prend une place prépondérante grâce à des modèles éléments finis de plus en plus réalistes et précis. Cependant, leur mise en oeuvre est complexe : les modèles actuels ne permettent pas de décrire les propriétés d'endommagement et de rupture des matériaux biologiques et limitent donc leurs champs d'utilisation pour la description des mécanismes de blessures. De plus, leur biofidélité concerne essentiellement la description géométrique et structurelle des différents organes et tissus. L'objectif de ce travail porte donc sur l'amélioration de la description des mécanismes lésionnels des os et l'étude des possibilités de personnalisation des propriétés mécaniques pour rendre compte de la variabilité biologique. Après avoir étudié les spécificités du comportement mécanique de l'os et un ensemble de lois de comportement, nous avons choisi un modèle d'endommagement le plus approprié. Cette loi a été validée d'un point de vue thermodynamique. Puis elle a été adaptée à une formulation éléments finis, pour être implémentée dans une plate-forme numérique de calcul dynamique explicite. Pour son adaptation, nous avons fait des choix scientifiques mais aussi des choix de « circonstance » imposés par la formulation spécifique des calculs dynamiques explicites. Afin de rendre compte des différences interindividuelles, nous avons étudié l'influence de certains paramètres tels que la porosité, la minéralisation, l'âge ou le sexe, sur les propriétés mécaniques des os. Nous avons également réalisé des essais de flexion d'os longs. Ces essais ont une double finalité : étudier l'influence des paramètres biologiques et expérimentaux sur le comportement de fémurs et de tibias, et évaluer la loi de comportement par la simulation de ces essais. L'évaluation de la loi d'endommagement pour l'os a été effectuée à différentes échelles (simulations d'essais sur éprouvettes et des essais de flexion de fémurs). La loi donne des résultats tout à fait satisfaisants et propose un profil de rupture cohérent avec celui observé expérimentalement.

International audience; Lettuce mosaic potyvirus (LMV) causes severe disease of commercial lettuce crops. LMV isolates show wide biological variability, particularly in their ability to overcome the resistance genes described in Lactuca sativa. For a better understanding of the molecular interaction between lettuce and LMV, biological and molecular characterization of a collection of 10 LMV isolates known to differ in virulence or aggressiveness was performed. The ability of these isolates to overcome the resistance genes was reevaluated under standardized conditions. To study the molecular variability of LMV, an immunocapture-reverse transcription-poly-merase chain reaction technique, coupled with direct sequencing, was used to obtain nucleotide sequence data from three short regions of the LMV genome. Clustering analysis was performed and compared to the biological properties of the 10 isolates. Three groups of LMV isolates were discriminated based on the molecular data. These groups appear to correlate with the geographic origin of the isolates rather than with their pathogenicity. Sequence comparison with California isolates clearly showed that the California isolates are related to the western European isolates, raising the possibility of past exchanges of LMV between western Europe and California.