Studies on honey from the Algarve in view of its valorization

Tese de dout., Química, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2012

Evaluation of uv spectrophotometry for estimation of nitrite and nitrate in nitrified urine

Water is a limited resource for which demand is growing. Contaminated water from inadequate wastewater treatment provides one of the greatest health challenges as it restricts development and increases poverty in emerging and developing countries. Therefore, the connection between wastewater and human health is linked to access to sanitation and to human waste disposal. Adequate sanitation is expected to create a barrier between disposed human excreta and sources of drinking water. Different approaches to wastewater management are required for different geographical regions and different stages of economic governance depending on the capacity to manage wastewater. Effective wastewater management can contribute to overcome the challenges of water scarcity. Separate collection of human urine at its source is one promising approach that strongly reduces the economic and load demands on wastewater treatment plants (WWTP). Treatment of source-separated urine appears as a sanitation system that is affordable, produces a valuable fertiliser, reduces pollution of water resources and promotes health. However, the technical realisation of urine separation still faces challenges. Biological hydrolysis of urea causes a strong increase of ammonia and pH. Under these conditions ammonia volatilises which can cause odour problems and significant nitrogen losses. The above problems can be avoided by urine stabilisation. Biological nitrification is a suitable process for stabilisation of urine. Urine is a highly concentrated nutrient solution which can lead to strong inhibition effects during bacterial nitrification. This can further lead to process instabilities. The major cause of instability is accumulation of the inhibitory intermediate compound nitrite, which could lead to process breakdown. Enhanced on-line nitrite monitoring can be applied in biological source-separated urine nitrification reactors as a sustainable and efficient way to improve the reactor performance, avoiding reactor failures and eventual loss of biological activity. Spectrophotometry appears as a promising candidate for the development and application of on-line nitrite monitoring. Spectroscopic methods together with chemometrics are presented in this work as a powerful tool for estimation of nitrite concentrations. Principal component regression (PCR) is applied for the estimation of nitrite concentrations using an immersible UV sensor and off-line spectra acquisition. The effect of particles and the effect of saturation, respectively, on the UV absorbance spectra are investigated. The analysis allows to conclude that (i) saturation has a substantial effect on nitrite estimation; (ii) particles appear to have less impact on nitrite estimation. In addition, improper mixing together with instabilities in the urine nitrification process appears to significantly reduce the performance of the estimation model.

A simple genetic basis for complex social behaviour mediates widespread gene expression differences.

A remarkable social polymorphism is controlled by a single Mendelian factor in the fire ant Solenopsis invicta. A genomic element marked by the gene Gp-9 determines whether workers tolerate one or many fertile queens in their colony. Gp-9 was recently shown to be part of a supergene with two nonrecombining variants, SB and Sb. SB/SB and SB/Sb queens differ in how they initiate new colonies, and in many physiological traits, for example odour and maturation rate. To understand how a single genetic element can affect all these traits, we used a microarray to compare gene expression patterns between SB/SB and SB/Sb queens of three different age classes: 1-day-old unmated queens, 11-day-old unmated queens and mated, fully reproductive queens collected from mature field colonies. The number of genes that were differentially expressed between SB/SB and SB/Sb queens of the same age class was smallest in 1-day-old queens, maximal in 11-day-old queens and intermediate in reproductive queens. Gene ontology analysis showed that SB/SB queens upregulate reproductive genes faster than SB/Sb queens. For all age classes, genes inside the supergene were overrepresented among the differentially expressed genes. Consistent with the hypothesized greater number of transposons in the Sb supergene, 13 transposon genes were upregulated in SB/Sb queens. Viral genes were also upregulated in SB/Sb mature queens, consistent with the known greater parasite load in colonies headed by SB/Sb queens compared with colonies headed by SB/SB queens. Eighteen differentially expressed genes between reproductive queens were involved in chemical signalling. Our results suggest that many genes in the supergene are involved in regulating social organization and queen phenotypes in fire ants.

Histoire naturelle de Pline.

Saisi le 11 septembre 1797 à San Daniele del Friuli; cf. Laffitte, Bulletin du Bibliophile, 1989/2, 315

Annales de Gênes, par Cafaro.

Acquis le 13 germinal an VII (2 avril 1799), à l'ouverture de deux caisses adressées au conservatoire de la Bibliothèque nationale par le ministre de l'Intérieur, suite à un envoi de la commission des arts en Piémont, avec une note datée de Turin, 17 ventôse an 7 (7 mars 1799), note qui fut remise le 23 floréal an IX (12 mai 1801) au citoyen Capperonnier, administateur de la Bibliothèque nationale, par les conservateurs du département des Manuscrits; cf. B.n.F., département des Manuscrits, Archives Modernes 492, registre des acquisitions du département des Manuscrits an II-an XIV (1793-1805), f. 33 "3. Annales genuenses. Ms. in fol., un vol., écrit. du 13e s."; cf. Laffitte, Bulletin du Bibliophile, 1989/2, 316-318.

Breviarium Strigoniense.

Cf. notice du ms. par Leroquais, Bréviaires, III, 182-185 n° 591 et pl. XCIX; P. Radó, Libri liturgici manuscripti bibliothecarum Hungariae et limitropharum regionum, Budapest, 1973. Un bréviaire d'Esztergom a été imprimé en 1524 à Venise. F. 2-8v Calendrier à l'usage d'Esztergom, avec un grand nombre de saints d'origines diverses (2-7v); cf. Leroquais, op. cit., 182. À noter les saints non mentionnés dans les Acta sanctorum, ou du moins pas pour la date correspondante; ne sont pas relevés les saints hongrois considérés comme classiques par Radó, op. cit., passim : 4 févr., «Victoris m.»; 8 févr., «Juliani m.»; 13 févr., «Adalberti m.», signalé une fois dans Radó, op. cit., 96 d'après ms. Budapest, B. N. Hung., c. l. m. ae. 395; 15févr., «Faustiani m.»; 21 févr., «Septuaginta mm.», non signalé sous cette forme pour cette date dans Radó, op. cit.; 15 mars, «Hilarii conf. et pont.», non signalé sous cette forme pour cette date dans Radó, op. cit.; 17 mars, «Bernardi conf.»; 26mars, «Eustachii abb.», signalé une fois dans Radó, op. cit., 96 d'après ms. Budapest, B.N. Hung., c. l. m. ae. 395; 28 mars, «Gastuli m.», non signalé dans Radó, op. cit.; 3 juill., «Bonifacii ep.», non signalé dans Radó, op. cit.; 5 juill., «Dominici m.»; 4 août, «Gaudentii ep. et conf.», signalé une fois dans Radó, op. cit., 329 d'après ms. Budapest, B. N. Hung., c. l. m. ae. 408; 8 août, «Adventus sanguinis D. N. J. C.»; 31 août, «Pauli ep. et m.», non signalé dans Radó, op. cit.; 12 oct., «Quatuor milium mm.», non signalé dans Radó, op. cit., à rapprocher de quatuor mille octingenti septuaginta mm., cf. Radó, op. cit., 167 d'après ms. Esztergom, B. metropolitana Strigoniensis I. 20; 14 oct., «Cerbonii conf.»; 27 oct., «Vedasti m.»; 15 nov., «Martini conf.», non signalé pour cette date dans Radó, op. cit; 20 nov., «Aniani ep. [Aurelianensis] et conf.». Pour plusieurs saints du calendrier on ne trouve pas d'office dans le sanctoral, et vice versa. — «Sequitur tabula impositionis historiarum...» (8-8v). F. 11-76 Psautier férial (11-72). — Office des défunts à l'usage d'Esztergom (72v-76); cf. K. Ottosen, The responsories and versicles of the latin office of the dead, Aarhus 1993, 127 (description des ff.74v-75v = «BN8879B») et 180 (description des ff.72v-74v = «BN8879A»). F. 77-528v Temporal : «Incipit breviarium secundum chorum alme ecclesie Strigoniensis. Dominica prima in adventu Domini...» (77-282v). Sanctoral : «Incipit secunda pars breviarii scilicet de festivitatibus. De s. Silvestro...» (286-486). À noter : office de l'Immaculée Conception composé par Léonard Nogarolo (480v). Commun des saints : «Incipit commune de sanctis et primo in vigilia unius apostoli...» (486v-513v). — «Sequitur de b. Virgine sabbatis diebus per estatem. Ad vesperas...» (513v-516v). «In quotidianis horis b. Virginis...» (516v-525). — «Sequuntur preces in quadragesima...» (525-526v). — «Sequuntur suffragia sabbatis diebus per estatem...» (526v-528), dont suffrages des ss. [Stephani regis Hungariae; Emerici ducis] (527), [Ladislai regis Hungariae; Adalberti ep. Pragensis et m.] (527v). — «Absolutio excommunicati...» (528-528v). 106 hymnes mentionnées dans la table des incipit, dont une non répertoriée dans Chevalier, Repert. hymn. ni dans les A. H., pour les confesseurs : «Christe lucis splendor vere fabrice mundi semper nobis parcens miserere confessorum precibus//...» (506v); cf. P. Radó, Répertoire hymnologique des mss. liturgiques dans les bibliothèques publiques de Hongrie, Budapest 1945, n° 111, relevée une fois dans le ms. Budapest, Bibl. nat. Hung. c. l. m. ae. 132, ms. décrit par Radó, Libri liturgici..., op. cit., 395-400.

Breviarium Strigoniense.

Cf. notice du ms. par Leroquais, Bréviaires, III, 182-185 n° 591 et pl. XCIX; P. Radó, Libri liturgici manuscripti bibliothecarum Hungariae et limitropharum regionum, Budapest, 1973. Un bréviaire d'Esztergom a été imprimé en 1524 à Venise. F. 2-8v Calendrier à l'usage d'Esztergom, avec un grand nombre de saints d'origines diverses (2-7v); cf. Leroquais, op. cit., 182. À noter les saints non mentionnés dans les Acta sanctorum, ou du moins pas pour la date correspondante; ne sont pas relevés les saints hongrois considérés comme classiques par Radó, op. cit., passim : 4 févr., «Victoris m.»; 8 févr., «Juliani m.»; 13 févr., «Adalberti m.», signalé une fois dans Radó, op. cit., 96 d'après ms. Budapest, B. N. Hung., c. l. m. ae. 395; 15févr., «Faustiani m.»; 21 févr., «Septuaginta mm.», non signalé sous cette forme pour cette date dans Radó, op. cit.; 15 mars, «Hilarii conf. et pont.», non signalé sous cette forme pour cette date dans Radó, op. cit.; 17 mars, «Bernardi conf.»; 26mars, «Eustachii abb.», signalé une fois dans Radó, op. cit., 96 d'après ms. Budapest, B.N. Hung., c. l. m. ae. 395; 28 mars, «Gastuli m.», non signalé dans Radó, op. cit.; 3 juill., «Bonifacii ep.», non signalé dans Radó, op. cit.; 5 juill., «Dominici m.»; 4 août, «Gaudentii ep. et conf.», signalé une fois dans Radó, op. cit., 329 d'après ms. Budapest, B. N. Hung., c. l. m. ae. 408; 8 août, «Adventus sanguinis D. N. J. C.»; 31 août, «Pauli ep. et m.», non signalé dans Radó, op. cit.; 12 oct., «Quatuor milium mm.», non signalé dans Radó, op. cit., à rapprocher de quatuor mille octingenti septuaginta mm., cf. Radó, op. cit., 167 d'après ms. Esztergom, B. metropolitana Strigoniensis I. 20; 14 oct., «Cerbonii conf.»; 27 oct., «Vedasti m.»; 15 nov., «Martini conf.», non signalé pour cette date dans Radó, op. cit; 20 nov., «Aniani ep. [Aurelianensis] et conf.». Pour plusieurs saints du calendrier on ne trouve pas d'office dans le sanctoral, et vice versa. — «Sequitur tabula impositionis historiarum...» (8-8v). F. 11-76 Psautier férial (11-72). — Office des défunts à l'usage d'Esztergom (72v-76); cf. K. Ottosen, The responsories and versicles of the latin office of the dead, Aarhus 1993, 127 (description des ff.74v-75v = «BN8879B») et 180 (description des ff.72v-74v = «BN8879A»). F. 77-528v Temporal : «Incipit breviarium secundum chorum alme ecclesie Strigoniensis. Dominica prima in adventu Domini...» (77-282v). Sanctoral : «Incipit secunda pars breviarii scilicet de festivitatibus. De s. Silvestro...» (286-486). À noter : office de l'Immaculée Conception composé par Léonard Nogarolo (480v). Commun des saints : «Incipit commune de sanctis et primo in vigilia unius apostoli...» (486v-513v). — «Sequitur de b. Virgine sabbatis diebus per estatem. Ad vesperas...» (513v-516v). «In quotidianis horis b. Virginis...» (516v-525). — «Sequuntur preces in quadragesima...» (525-526v). — «Sequuntur suffragia sabbatis diebus per estatem...» (526v-528), dont suffrages des ss. [Stephani regis Hungariae; Emerici ducis] (527), [Ladislai regis Hungariae; Adalberti ep. Pragensis et m.] (527v). — «Absolutio excommunicati...» (528-528v). 106 hymnes mentionnées dans la table des incipit, dont une non répertoriée dans Chevalier, Repert. hymn. ni dans les A. H., pour les confesseurs : «Christe lucis splendor vere fabrice mundi semper nobis parcens miserere confessorum precibus//...» (506v); cf. P. Radó, Répertoire hymnologique des mss. liturgiques dans les bibliothèques publiques de Hongrie, Budapest 1945, n° 111, relevée une fois dans le ms. Budapest, Bibl. nat. Hung. c. l. m. ae. 132, ms. décrit par Radó, Libri liturgici..., op. cit., 395-400.

The impact of the Multicolor Asian Lady Beetle (Harmonia axyridis) on wine quality /

The Impact of the Multicolor Asian Lady Beetle (Harmonia axyridis) on Niagara Wine Quality The possible influence of Harmonia axyridis (the Multicolored Asian Lady Beetle) on the sensory properties of wine was investigated. H. axyridis beetles were added to white and red grape musts at a rate of 0, 1 or 10 per L, and a trained panel evaluated the finished wines using flavor-profiling techniques. Significant modification of both wine aroma and flavor characteristics were observed in the 10 beetlelL treatments, with smaller effects noted at the 1 beetlelL rate. Vinification in the presence of H. axyridis gave higher intensity scores for peanut, bell pepper and asparagus aromas and flavors in the white wines, and peanut, asparagus/bell pepper, and earthy/herbaceous aromas and flavors in the red wines. In addition, sweet, acid and bitter tastes were affected in red wines, and a general trend of decreasing fruit and floral intensities with increasing beetle rate was observed in both white and red wines. 15 ngIL Isopropylmethoxypyrazine was added to control wines and sensory profiles similar to high beetle treatments were obtained, supporting the hypothesis that methoxypyrazines from beetles are implicated in the taint. A trained panel evaluated the treated wines after 10 months of aging using the same sensory methods described above. Sensory profiles were very similar. Fennenting in the presence of Harmonia Axyridis (HA) had little influence on the chemical composition of the ftnished wine. The notable exception IS Isopropylmethoxypyrazine content, which was assessed usmg GC-MS analysis and showed increased concentration with increasing beetle nwnber for both white and red wmes. The influence of potential remedial treatments on the sensory properties of white and red wines tainted by Harmonia axyridis were also investigated. Bentonite, activated charcoal, oak chips, de-odorized oak chips, and UV or light irradiation were applied to tainted wine, and these wines evaluated chemically and sensorially. Both white and red wines treated with oak chips had strong oak characteristics, which masked the Harmonia axyridis-associated aroma and flavour attributes. In red wine, asparagus/bell pepper characteristics were decreased by bentonite and charcoal treatments. Only activated charcoal significantly decreased methoxypyrazine levels and only in white wine.

An investigation of sugar feeding by black flies (Diptera: Simuliidae)

Although much research has been conducted on blood-meal acquisition in adult female black flies (Diptera: Simuliidae), the same cannot be said for sugarmeals. Both sexes feed on sugar which provides energy for flight and it has been commonly held that nectar is the major carbohydrate source. This thesis addresses the question of whether a non-floral carbohydrate source, specifically homopteran honeydew, is ingested by male and female black flies. Black flies reared in the laboratory have been observed to readily ingest freshly excreted and older (dry) honeydew when presented with honeydew coated tamarack branches. Field work was conducted in Algonquin Park, Ontario in the spring and summer of 1993. Three separate studies were designed to test whether homopteran honeydew is an important carbohydrate source for black flies and whether flies from different habitats utilize different sugar sources. The sugars melezitose and / or stachyose are known to occur in a variety of homopteran honeydews and therefore were used as indicators of honeydew feeding by black flies. In the first study, black flies were collected with insect nets from a stand of Larix larcina heavily infested with honeydew - producing homopterans (Adelges lariciatus). Six black fly species were captured: Simulium venustum, S. rostra tum, S. vittatum, Stegopterna mutata, S. aureum and S. quebecense. Samples of honeydew and individual black flies were tested using thin layer chromatography (T. L. C.) with fructose, glucose, sucrose, turanose, melezitose, raffinose and stachyose as standards. All sugars except turanose and melezitose were found in the adelgid honeydew samples. Since the sugar melezitose was absent from ~ honeydew samples, stachyose was used to indicate that black flies were feeding from this particular honeydew source. Of the 201 black flies tested, 194 contained sugars which occurred in 16 combinations. Stachyose combinations excluding melezitose, present in 45.9 % of flies, were used to indicate that black flies had been feeding on the adelgid honeydew. In the second study, black flies were collected in the morning and evening on 8 collection dates, using a vehicle mounted insect net. The crops and midguts of 10 male and 10 female Simulium venustum were dissected on each sample date. In total the gut contents of 320 individual flies were analysed by T. L. C. The sugars identified from these flies were present in the following proportions: fructose (100.0%), glucose (100.0%), sucrose/turanose (50.4%), melezitose (30.3%), raffinose (18.8%) and stachyose (8.7%). These sugars occurred in fourteen different combinations. It is argued that the presence of melezitose and / or stachyose indicates that black flies had fed on homopteran honeydew. Significantly more female flies (40.0%) than male flies (27.5%) had fed on honeydew. In the third study, adult black flies were sampled by sweep netting vegetation in four habitats in the morning and evening on 8 collection dates. The habitats are as follows: (1) Davies Bog, (2) Abandoned Air Field (dominated by blueberries, Vaccinium spp.), (3) Deciduous Habitat and (4) Coniferous Habitat. Sugars in the crops and midguts of female flies were tested by T. L. C. and, for S. venustum, it was found that significantly fewer flies (18.8%) from the Air Field contained honeydew than from the other three sites (Davies Bog, 34.4%; Deciduous Habitat, 36.2%; Coniferous Habitat, 25.0%). Of the 1287 black flies tested individually by T. L. C. 441 (34.3%) contained melezitose and / or stachyose sugars indicating that this proportion of the population were feeding from Homopteran honeydew. It is therefore clear that floral (nectar) sugars are not the only source of carbohydrates available to black flies.

Charles C. Chapman's birthday celebration, Fullerton, California,1932

Family portrait taken at Charles C. Chapman's birthday celebration, Fullerton, California,July 2, 1932. The group poses outside his residence on the lawn. Top row [left to right]: Arthur Irvin, Charles Wickett, Irvin Chapman, Sam Collins, Paul Williams, Grant Chapman,, Sidney Chapman, Clay McCarn, Earl Chapman's son David McDougal, Earl Chapman's son William McDougal, Earl Chapman, Harry Chapman, William Wickett Sr. Second row [left to right]: Mr. VanMeter, Mrs. Sinclair, C. C. Sinclair, John Franklin, Way Bagley, Marjorie Collins, Emma Williams, Ruth Chapman, Vesta Chapman, Inez Bagley, Grace Chapman, Bertha Chapman, Clough Chapman, Frank and Bertha Chapman's daughter Agnes McDougal [Streech], Georgiana Chapman, Thela Clough, Mrs. Earl [Ann] Chapman, Bessie Reynolds, Fred Chapman, E. B. [Bert] Reynolds. Seated [left to right]: Mrs. VanMeter, Hattie Clark, Louie Messlar, Charlie Thamer, Louella Thamer, Dolla Harris, Stanley Chapman Sr. holding Mary Anne, Ethel Wickett, Charles C. Chapman, Clara Chapman, Colum C. Chapman, Aunt Annie Colum, Deryth Chapman, Anna Marie Chapman, Floy Chapman, Edith Chapman. Front row [left to right]: Sam E. Collins, Bill Wickett Jr., Joyce Chapman, Marilyn Chapman, Elizabeth Chapman, Mary McCarn, Nina Chapman Lescher, Jodeane Collins, Bob Gibb, Jean Chapman. In front is a floral arrangement with drawing of a Western Union telegram "To Chas. C. Chapman, July 2, 1932, N. Fullerton, Cal., 'Wishing you a happy birthday, Nina."

Characterisation and optimisation of the flavour of health-promoting, plantderived bitterants in functional beverages.

Flavour is a combination of taste, odour, and chemesthetic sensations. Close associations exist between these sensory modalities, and thus, the overall flavour of a food or beverage product can change when the intensity of one or more of these sensations is altered. Strategies to modify flavour are often utilized by the food industry, and are central to the engineering of new and reformulated products. For functional food and beverages, flavour modification is particularly important, as fortifying agents can elicit high levels of less than desirable sensations, such as bitterness and astringency. The application of various flavour modifying strategies can decrease the perceived intensity of these sensations, and in tum, improve the sensory profile of the product. This collection of studies describes the sensory characteristics of experimental functional beverages fortified with trans-resveratrol, (+)-catechin, and/or caffeine, and examines the impact of novel flavour modifying strategies on the perceived flavour of these beverages. In the first study, results demonstrate that the flavour profile of Cabemet Sauvignon wines fortified with 20 mglL and 200 mg/L of trans-resveratrol is not perceived as different compared to control wine (0 mglL). However, Riesling wine fortified with 200 mg/L is perceived as significantly higher in bitterness compared to 20 mglL and control. For some functional food formulations, alternative strategies for flavour modification are needed. Traditional methods, such as the addition of sucrose and sodium chloride, may decrease the perceived 'healthiness' of a product, and thus, may be sub-optimal. In a second study, high and low concentrations of five different bitter inhibiting compounds - 'bitter blockers' - (B-cyclodextrin, homoeridictyol sodium salt, carboxymethylcellulose - low viscosity, zinc sulfate, magnesium sulfate) were tested for their efficacy towards decreasing the bitterness of high and low concentrations of caffeine and (+)catechin - two health-relevant, plant-derived bitterants. B-cyclodextrin and homoeridictyol sodium salt were the most effective blockers at decreasing (+ )-catechin and caffeine, respectively. In addition to bitter blockers, additional flavour modifying strategies, either alone or in combination - may also be successful in functional food formulations. Both sucrose and rebaudioside A - a plant-derived sweetener - were effective at decreasing the bitterness of (+)catechin. When added to (+)-catechin along with B-cyc1odextrin, both sweeteners provided the most effective decrease in bitterness compared to binary, ternary, or quaternary mixtures of (+)catechin together with bitter blockers, sweeteners, andlor odourants. The perceived intensity of sensations elicited by sweeteners and odourants was not affected by the addition of bitter blockers, and thus, their impact within these complex matrices is minimal. In addition, withinmodal (taste-taste) compared to cross-modal (taste-odour) sensory interactions were more effective at decreasing the bitterness of (+ )-catechin. Overall, results from these studies demonstrate that certain novel, alternative flavour modifying approaches may be successful towards lowering the bitterness and astringency elicited by (+ )-catechin and caffeine in aqueous solutions.

IMPACT OF CROP LEVEL AND HANG TIME ON THE COMPOSITION OF FOUR WINE GRAPE CULTIVARS FROM THE NIAGARA REGION

This study analyzed the use of two viticultural practices: “crop level” (half crop; HC, and full crop; FC) and “hang times”, and their impact on the composition of four grape cultivars; Pinot gris, Riesling, Cabernet Franc and Cabernet Sauvignon from the Niagara Region and wine volatile composition by GC-MS. It was hypothesized that keeping a full crop with a longer hang time would have a greater impact on wine quality than reducing the crop level. In all cultivars, a reduction of crop level induced reductions in yield, clusters per vine and crop load, with increases in Brix. Extended hang time also increased Brix related to desiccation. The climatic conditions at harvest had an impact on hang time effects. The GC-MS analysis detected the presence of 30 volatile components in the wine, with different odour activity values. Harvest time had a positive impact than crop reduction in almost all compounds.

Evaporative respiratory cooling augments pit organ thermal detection in rattlesnakes

Rattlesnakes use their facial pit organs to sense external thermal fluctuations. A temperature decrease in the heat-sensing membrane of the pit organ has the potential to enhance heat flux between their endothermic prey and the thermal sensors, affect the optimal functioning of thermal sensors in the pit membrane and reduce the formation of thermal ‘‘afterimages’’, improving thermal detection. We examined the potential for respiratory cooling to improve strike behaviour, capture, and consumption of endothermic prey in the South American rattlesnake, as behavioural indicators of thermal detection. Snakes with a higher degree of rostral cooling were more accurate during the strike, attacking warmer regions of their prey, and relocated and consumed their prey faster. These findings reveal that by cooling their pit organs, rattlesnakes increase their ability to detect endothermic prey; disabling the pit organs caused these differences to disappear. Rattlesnakes also modify the degree of rostral cooling by altering their breathing pattern in response to biologically relevant stimuli, such as a mouse odour. Our findings reveal that low humidity increases their ability to detect endothermic prey, suggesting that habitat and ambush sites election in the wild may be influenced by external humidity levels as well as temperature.

Symbolique florale dans le tableau de Jean-Baptiste Belin de Fontenay Vase d’or, fleurs et buste de Louis XIV (1687)

Le tableau de Jean-Baptiste Belin de Fontenay intitulé Vase d’or, fleurs et buste de Louis XIV est le morceau de réception que le peintre a présenté à l’Académie royale de peinture et de sculpture en 1687. Malheureusement peu étudié, ce tableau n’en comporte pas moins trois problématiques très intéressantes. Tout d’abord, il rassemble trois genres de peinture dans une seule composition : la nature morte, le portrait et la peinture d’histoire, illustrés respectivement par les fleurs, le buste du roi et la pièce d’armure. L’association de ces trois genres dans un tableau de nature morte est peu commune dans la peinture française du 17e siècle. Il est donc nécessaire de vérifier s’il existe un lien entre les fleurs, l’image de Louis XIV et l’armure. Ensuite, le contraste entre la polychromie des fleurs et la monochromie de la sculpture et de l’ameublement est frappante ; il est possible de lier ce contraste au phénomène des débats entre le dessin et la couleur de l’Académie royale de peinture et de sculpture à la deuxième moitié du 17e siècle. D’ailleurs, les fleurs, qui n’étaient pas le sujet central dans le programme original de Le Brun, deviennent le sujet principal du tableau et occupent une place plus importante que le buste de Louis XIV. Cette modification n’a cependant pas choqué les juges de l’Académie puisque la toile a été acceptée sans contestation. Elle amène donc à s’interroger sur la hiérarchie des genres de peinture qui est la doctrine officielle de l’Académie royale de peinture et de sculpture de l’époque. Le noyau de la recherche consiste à vérifier si les fleurs n’occupent qu’une simple fonction décorative ou si elles peuvent être associées à des symboles. Notre recherche examine d’abord l’utilisation des symboles floraux dans la culture française du 17e siècle. Par la suite, elle étudie cette utilisation dans le domaine politique, à savoir que les fleurs pourraient être liées à la louange de Louis XIV. Enfin, elle analyse les domaines artistiques et esthétiques, c’est-à-dire la façon dont le tableau reflète, par l’utilisation des symboles floraux, l’évolution des théories de l’art, la hiérarchie des genres de peinture et les débats du dessin et de la couleur, en France, durant la deuxième moitié du 17e siècle.

L’intégration de modalités sensorielles : l’influence de l’olfaction sur la vision

La plupart des études sur la perception isolent une modalité sensorielle pour mieux l’étudier et la comprendre. Malheureusement, aucun de nos sens ne représente la seule source d’information, car une intégration sensorielle se fait en tout moment lors de la perception de l’environnement. L’information d’un sens est donc plutôt en accord ou en conflit avec l’apport d’information des autres sens. Le but de la présente étude était d’investiguer, par IRMf, les activations cérébrales d’une intégration visuelle et olfactive lorsque ces deux perceptions sont congruentes. Pour ce faire, une image et/ou une odeur étaient présentées au sujet et ce dernier devait identifier si le stimulus perçu était congruent. Ce protocole permettait d’observer les activations cérébrales lors de l’analyse d’un stimulus et la prise de décision selon la congruité du stimulus présenté. La condition de congruence vision-odeur activa les zones visuelles et olfactives plus fortement que lors des conditions contrôle (image seule, odeur seule). Ces résultats illustrent une potentialisation des aires visuelles et olfactives par une intégration d’information congruente venant de ces deux modalités. Par conséquent, l’intégration d’un stimulus visuel et odorant congruent semble rehausser la perception du stimulus.