L'obésité constitue l'un des principaux problèmes de santé publique en ce début du 21ème siècle. Sa prévalence augmente régulièrement, en particulier chez les enfants. Ce constat n'est pas anodin car l'obésité est généralement associée à diverses pathologies graves (diabète de type 2, hypertension et cancer,…). Ainsi, des investigations sur les mécanismes impliqués dans la perception gustative des lipides alimentaires pourraient éclairer leurs rôles dans l’incidence de l’obésité.Plusieurs études ont démontré le rôle des endocannabinoïdes et des aliments amers dans l’obésité. Ainsi, nous avons étudié l’interaction (cross-talk) des récepteurs cannabinoïdes et du goût amer avec le goût lipidique. Cette thèse comporte ainsi deux volets : les récepteurs cannabinoïdes (CB1R), le goût amer et leurs interactions avec les récepteurs lipidiques.Dans la première partie, nous avons étudié le rôle régulateur de CB1R. Dans la présente étude, des tests comportementaux sur des souris CB1R-/- et des souris de type sauvage (WT) ont montré que l'invalidation du gène Cb1r était associée à une faible préférence pour les solutions contenant de l'huile de colza ou un acide gras à longue chaîne (AGLC) tel que l’acide linoléique (LA). L'administration de rimonabant, un agoniste-inverse de CB1R, chez la souris a également entraîné une faible préférence pour les acides gras alimentaires. Aucune différence dans l'expression des protéines CD36 et GPR120 n'a été observée dans les cellules des papilles gustatives des souris WT et CB1R-/-. La signalisation calcique via CD36 dans les cellules des papilles gustatives des souris CB1R-/- diminue de façon significative par rapport à celle observée dans les cellules gustatives des souris WT. Les cellules des papilles gustatives des souris CB1R-/- présentent également une diminution significative de l'ARNm de Pro-glucagon et de Glp-1r et un faible niveau basal de GLP-1. Nous rapportons que CB1R est impliqué dans la perception du goût du gras via la signalisation calcique et la sécrétion de GLP-1.Dans la seconde partie, nous avons d’abord caractérisé le phénotype de cellules fongiformes humaines (HTC-8). En effet, le projet de ma thèse comprend la caractérisation à l’échelle moléculaire des récepteurs amers et lipidiques et leur cross-talk dans ces cellules (collaboration BRAIN, Allemagne). Nous avons démontré que les cellules HTC-8 expriment PLCβ2 et l’α-gustducin à l’échelle des ARNm et des protéines. Elles expriment également TAS2R16 et TAS2R38 et ces mêmes cellules co-expriment CD36 et GPR120. Puis, nous avons étudié la signalisation via ces récepteurs en utilisant l’acide linoléique, un agoniste de CD36 et GPR120, la sinigrin, agoniste de TAS2R16 et TAS2R38, la salicin, agoniste du récepteur TAS2R16 et le phénylthiocarbamide, agoniste du récepteur TAS2R38. De plus, les études du signal calcique ont démontré que la signalisation en aval du goût gras partage une voie commune avec la signalisation en aval du goût amer, mettant en évidence un cross-talk entre ces deux modalités gustatives.Bien que nous ayons montré le cross-talk entre les modalités gustatives amère et lipidique, il nous reste à étudier ces phénomènes à l’échelle de l’organisme. Ces résultats, d’ores et déjà, montrent que le goût amer et le récepteur cannabinoïde-1 sont liés à la sensibilité au goût du gras et doivent être pris en compte pour la gestion de l'obésité. / Obesity is one of the major public health problems at the beginning of the 21st century. Its prevalence is increasing steadily, especially among children. This observation is not insignificant because obesity is generally associated with various serious pathologies (type 2 diabetes, hypertension and cancer, etc.). Thus, investigations into the mechanisms involved in the taste perception of dietary lipids could shed light on their roles in the incidence of obesity.Several studies have demonstrated the role of endocannabinoids and bitter foods in obesity. Thus, we studied the cross-talk of cannabinoid receptors and bitter taste with lipid taste. This thesis has two components: cannabinoid receptors (CB1R), bitter taste and their interactions with lipid receptors.In the first part, we studied the regulatory role of CB1R. In the present study, behavioral tests on CB1R-/- mice and wild-type (WT) mice showed that the invalidation of the Cb1r gene was associated with a low preference for solutions containing rapeseed oil or a long chain fatty acid (LCFA) such as linoleic acid (LA). Administration of rimonabant, a CB1R inverse agonist, in mice also resulted in a low preference for dietary fatty acids. No differences in the expression of CD36 and GPR120 proteins were observed in the taste buds cells of the WT and CB1R-/- mice. Calcium signaling via CD36 in the taste bud cells of CB1R-/- mice decreased significantly compared with those observed in the taste cells of WT mice. The taste bud cells of CB1R-/- mice also show a significant decrease in Pro-glucagon and Glp-1r mRNA and a low basal level of GLP-1. We report that CB1R is involved in the perception of fat taste via calcium signaling and secretion of GLP-1.In the second part, we first characterized the phenotype of human fungiform cells (HTC-8). Indeed, the project of my thesis includes the characterization on the molecular scale of bitter and lipid receptors and their cross-talk in these cells (collaboration BRAIN, Germany). We have demonstrated that HTC-8 cells express PLCβ2 and α-gustducin at the mRNA and protein level. They also express TAS2R16 and TAS2R38 and these same cells co-express CD36 and GPR120. Then, we studied signaling via these receptors using linoleic acid, a CD36 and GPR120 agonist, sinigrin, TAS2R16 agonist and TAS2R38, salicin, TAS2R16 receptor agonist, and phenylthiocarbamide, TAS2R38 receptor agonist. In addition, calcium signal studies have shown that downstream fatty signaling shares a common path with downstream bitter taste signaling, highlighting a cross-talk between these two taste modalities.Although we have shown the cross-talk between bitter and lipid taste modalities, we still have to study these phenomena at the level of the organism. These results, already, show that the bitter taste and the cannabinoid-1 receptor are related to the taste sensitivity of fat and must be taken into account for the management of obesity

The main aim of this work was to evaluate the effect of controlled atmosphere on postharvest conservation of yerba mate. The following aspects were evaluated: color, chlorophylls concentration, carotenoids and phenolic compounds, foaming, mold and yeast count and the bitter taste of yerba mate. Thus, three experiments were performed from samples of yerba mate from Arvorezinha (RS) and São Mateus do Sul (PR) in the form [1] thickly ground ( cancheada ) and thinly milled ( socada ) were stored in four oxygen levels (1, 3, 6 and 20.9 kPa O2) and four dioxide carbon levels (0, 3, 6 and 18 kPa CO2), and analyzed, after nine months of storage [2] native and cultivated yerba mate stored at room temperature, 1.0 kPa O2 and 3.0 kPa CO2 analyzed after 0, 3, 6 and 12 months of storage. [3] native and cultivated yerba mate from São Mateus do Sul (PR) stored in an atmosphere containing: 20.9 O2 + 0.03 CO2; 0.5 O2 + 0.03 CO2; 1.0 O2 + 0.03 CO2; 1.0 O2 + 3.0 CO2; 1.0 O2 + 18 CO2 which were analyzed after six months of storage. The results demonstrate that the condition 1.0 kPa O2 maintain the yerba mate greener and with a higher chlorophylls concentration and total phenolic compounds. The CO2 partial pressure maintain yerba mate coloration greener and with a higher chlorophylls concentrationand total phenolic compounds, regardless of the level used, in the yerba mate from both cultivation areas. The yerba mate thickly ground ( cancheada ) presented a better storage potential than the thinly milled ( socada ). Total chlorophyll concentration reduced exponentially during the storage time independently of the storage condition, form of cultivation and place that the yerba mate was cultivated, since the total carotenoid independently of the form and place of cultivation decreased to 3 months storage under atmosphere of 1.0 kPa O2. When stored in 3.0 kPa CO2, the reduction was over 12 months of storage. Dioxide carbon increasing in the storage chamber increases the phenolic compounds concentration until six month of storage. Raw material originated from São Mateus do Sul-PR has higher chlorophyll concentration, greener color resulting in greater storage potential of this yerba mate. When evaluating the combination of gases, we observed that CA condition with 0.5 kPa O2 + 0.03 kPa CO2 maintained yerba mate greener, with higher chlorophyll concentration and phenolic compounds concentrations after 6 months of storage. As for the foam, controlled atmosphere had a positive effect on its maintenance. The native yerba mate showed higher green color preservation in relation to the cultivated. There was no increase in yeast and molds in yerba mate of CA storage. Yerba mate, independently of type, stored in 1.0 kPa O2 + 0.03 kPa CO2 was selected in a sensorial panel as the most bitter and under air conditions (20.9 kPa O2 + 0.03 kPa CO2) as the lesser bitter, however, the most preferred yerba mate stored under 0.5 O2 kPa + 0.03 kPa CO2. / O objetivo principal deste trabalho foi avaliar o efeito da atmosfera controlada na conservação pós-colheita de erva-mate. Para tanto os seguintes aspectos foram avaliados: coloração, concentração de clorofilas, carotenóides e compostos fenólicos totais, formação de espuma, contagem de bolores e leveduras e o sabor amargo do chimarrão. Para tal, foram efetuados três experimentos a partir de amostras de erva-mate provenientes de Arvorezinha (RS) e São Mateus do Sul (PR), na forma [1] cancheada e socada, foram armazenadas em quatro níveis distintos de oxigênio (1, 3, 6 e 20,9 kPa de O2) e quatro níveis distintos de gás carbônico (0, 3, 6 e 18 kPa de CO2), as quais foram analisadas ao final de nove meses de armazenamento. [2] Erva-mate nativa e cultivada armazenadas a temperatura ambiente, 1,0 KPa de O2 e 3,0 KPa de CO2, analisadas após 0, 3, 6 e 12 meses de armazenamento. [3] Erva-mate nativa e cultivada provenientes de São Mateus do Sul (PR) armazenadas em atmosfera, contendo: 20,9 O2+0,03 CO2; 0,5 O2+0,03 CO2; 1,0 O2+0,03 CO2; 1,0 O2+3,0 CO2; 1,0 O2+18 CO2 as quais foram analisadas ao final de seis meses de armazenamento. Os resultados demonstram que a condição 1,0 kPa de O2 mantém a erva-mate mais verde, maior teor de clorofilas e compostos fenólicos totais. A pressão parcial de CO2, independente do nível, mantém a coloração da erva-mate mais verde, maior teor de clorofilas e compostos fenólicos totais, nos dois locais de cultivo. A erva-mate cancheada apresentou um melhor potencial de armazenamento do que a erva-mate socada. Concentração de clorofila total reduziu exponencialmente durante o tempo de armazenamento, independentemente da condição de armazenamento, forma de cultivo e local que a erva-mate foi cultivada, já os teores de carotenóides totais independente da forma e local de cultivo, apresentaram redução até os 3 meses de armazenamento sob atmosfera de 1,0 KPa de O2, já quando armazenadas em 3,0 KPa de CO2, a redução dos carotenóides foi ao longo dos 12 meses de armazenamento. A presença de CO2 na atmosfera de armazenamento eleva a concentração de compostos fenólicos totais até seis meses. A matéria-prima proveniente de São Mateus do Sul-PR tem maior preservação da cor verde o que resulta em maior potencial de armazenamento. Ao avaliar a combinação dos gases, foi possível verificar que a condição 0,5 O2 + 0,03 CO2 manteve a erva-mate mais verde, maior teor de clorofilas e compostos fenólicos totais após seis meses de armazenamento. Quanto à espuma, a atmosfera controlada apresentou efeito positivo na sua manutenção. A erva-mate nativa apresentou uma maior preservação da cor verde do que a erva-mate cultivada. Não houve aumento das contagens de bolores e leveduras na erva-mate nas condições de armazenamento em AC. A erva-mate, indiferente do tipo, armazenada a 1,0 O2+0,03 CO2 foi a selecionada sensorialmente como a mais amarga e erva-mate armazenada a 20,9 O2+0,03 CO2 como a menos amarga, no entanto a preferida foi a erva-mate armazenada a 0,5 O2+0,03 CO2.

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The evolutionary history of H. neanderthalensis, interwoven with that of H. sapiens, has always fascinated the scientific world. Recent adavncess in paleogenetics shedds new light on the phylogenetic relationship between Neandertals and modern humans. The studies developed in this thesis intend principally to control the contaminants through the development of an anti-contamination protocol for decreasing the human contamination in pre-laboratory phases. We designed a PCR-based method specific for reducing human contamination during the laboratory analysis, and we analyzed the fragmentation pattern of the ancient sequences by massively parallel sequencing technologies. Furthermore, we studied two nuclear genes, TAS2R38 -associated to bitter taste perception- and ABO blood group system –involved in natural immunity- that provide specific information on aspects of the Neanderthal phenotype and adaptation. / La historia evolutiva d’H. neanderthalensis, imbricada amb la d’H. sapiens, ha fascinat sempre el món científic. Avenços recents en paleogenètica aporten una nova llum sobre la rel•lació filogenètica entre els neandertals i els humans moderns. Els treballs d’aquesta tesi intenten principalment controlar els contaminants mitjançant el desenvolupament d’un protocol d’anti-contaminació que disminueixi la contaminació humana de les mostres en la fase de pre-laboratori. Hem desenvolupat un mètode basat en la PCR específic per a reduïr els contaminants humans durant l’anàlisi en el laboratori, i hem analitzat el patró de fragmentació de les seqüències antigues amb tècniques de seqüenciació massiva en paral•lel. A més a més, hem estudiat dos gens nuclears, el TAS2R38 –associat a la percepció del gust amarg- i el grup sanguini ABO –implicat en la immunitat natural- que proporcionen informació específca sobre aspectes del fenotip i de les adaptacions dels neandertals.

The main topic of this thesis is the CUNC basic organization unit and Podblanické Ecocentre CUNC in Vlašim. The first part of the thesis presents the Czech Union for Nature Conservation (CUNC) followed by an overview of its Environmental Centres. The next section contains a summary of all the activities carried out by the CUNC basic organization unit and Podblanické Ecocentre CUNC in Vlašim from their establishment to the present and recapitulates the formation of these organisations themselves. The thesis also covers a characteristic of all the one-day as well as residential teaching programmes for secondary schools, technical schools and grammar schools carried out by the Ecocentre. The greatest emphasis is laid on four selected one-day teaching programmes, for which a research was conducted by using a questionnaire method. Its aim was to determine the influence on pupils and students of the educational programmes from secondary schools, technical schools and grammar schools.