References of "Maesen, Philippe"
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See detailThe taste of origin in a lady beetle: do males discriminate between females based on cuticular hydrocarbons?
Legrand, Pauline; Vanderplanck, Maryse; Marko, Istvan et al

in Physiological Entomology (2019)

The Asian lady beetle Harmonia axyridis originates from Asia and has established invasive populations at a worldwide scale. Recent population genetic studies have traced their invasion routes and ... [more ▼]

The Asian lady beetle Harmonia axyridis originates from Asia and has established invasive populations at a worldwide scale. Recent population genetic studies have traced their invasion routes and demonstrated that bottlenecks in population size have reduced their genetic diversity. As a consequence, phenotypical differences were highlighted between native and invasive populations. Among phenotypical traits, cuticular hydrocarbons (CHCs) might reflect geographical origin of a lady beetle, especially because of their genetic basis. Here, we investigated whether (i) the CHC profiles qualitatively and quantitatively differ between females of H. axyridis from native and invasive populations; and (ii) males discriminate females from native and invasive populations using CHC profiles. CHCs were solvent-extracted before being quantified and identified by gas chromatography and mass spectrometry. We detected a total of 17 CHCs from female elytra including six alkanes, three polyunsaturated and eight monounsaturated alkenes. The total quantity of CHCs differed among the populations with lady beetles from Tai’an (China) displaying a higher CHCs concentration than lady beetles from Gembloux (Belgium) and from Beijing (China) populations. Multivariate analyses detected differences in CHCs qualitative profiles, with females from Tai’an being different from the two other populations. Finally, our behavioural assays showed that females originating from the native Tai’an population were less preferred by males, while females from the invasive population were mounted more often. Our behavioural assays suggest that CHCs are not involved in discrimination of mating partners based on their origin. [less ▲]

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See detailCuticular hydrocarbon composition does not allow Harmonia axyridis males to identify the mating status of sexual partners
Legrand, Pauline; Vanderplanck, Maryse; Lorge, Stéphanie ULiege et al

in Entomologia Generalis (2019), 38(3), 211-224

Males of polyandrous species have to overcome sperm competition. They should select their mate based on the reproductive status of the female to increase their own fitness. Because the sexual behavior of ... [more ▼]

Males of polyandrous species have to overcome sperm competition. They should select their mate based on the reproductive status of the female to increase their own fitness. Because the sexual behavior of lady beetles relies on semiochemicals, with cuticular hydrocarbons (CHCs) being used for mate recognition, we developed and tested two hypotheses. First, we hypothesized that the cuticular hydrocarbon profile qualitatively and quantitatively differs between virgin and mated Harmonia axyridis females, regardless of the color morph. Second, we hypothesized that males discriminate virgin and mated females, preferring copulating with virgin females, rather than previously mated ones, to avoid sperm competition and subsequently increase their fitness. CHCs were solvent-extracted before being quantified and identified by gas chromatography. We found no qualitative differences between mated and unmated females irrespective of the morph; however, quantitative differences were detected. Specifically, the CHC profiles of mated females presented higher concentrations of alkenes, including 9-pentacosene, 9-heptacosene, and 9-hentriacontene. During dual-choice behavioral assays, males equally copulated with virgin and mated females. Our results suggest that there is no CHC-based discrimination strategy in virgin males of H. axyridis between virgin and once-mated females. We discuss alternative strategies that might be used in this lady beetle species. [less ▲]

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See detailImbrasia obscura, an Edible Caterpillar of Tropical Africa: Chemical Composition and Nutritional Value
Mabossy-Mobouna, Germain; Malaisse, François ULiege; Richel, Aurore ULiege et al

in TROPICULTURA (2018), Vol. 36, N° 4

The consumption of Imbrasia obscura (Butler, 1878) has been quoted in a dozen books and papers in five different countries, namely Cameroon, Central African Republic, Congo Republic, Democratic Republic ... [more ▼]

The consumption of Imbrasia obscura (Butler, 1878) has been quoted in a dozen books and papers in five different countries, namely Cameroon, Central African Republic, Congo Republic, Democratic Republic of Congo and Angola. This study presents, for the first time, information concerning two unknown subjects, the chemical composition and the nutritional value of the species. The chemical composition shows that it is a good source of proteins and lipids with the presence of five essential amino-acids (threonine, tyrosine + phenylalanine, histidine and tryptophan) and important amounts of essential fatty acids. The mineral elements such as calcium, phosphorus, magnesium and potassium are also present in good amounts. There is little sodium for which human consumption is frequently excessive. The very high proportion of alpha-linoleic acid contributes very significantly to the low ω-6/ω-3 ratio. Consequently, this caterpillar is a food that may be recommended for human consumption. Farming this species could be encouraged because of its high nutritional value and its good commercial potential especially in areas where malnutrition is common. [less ▲]

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See detailChimie: rupture et paradoxe
Richel, Aurore ULiege; Maesen, Philippe ULiege

Speech/Talk (2018)

« La chimie, envisagée comme une science indépendante, offre un des moyens les plus puissants d’élever les esprits, et son étude est utile non seulement en ce qu’elle sert les intérêts matériels de ... [more ▼]

« La chimie, envisagée comme une science indépendante, offre un des moyens les plus puissants d’élever les esprits, et son étude est utile non seulement en ce qu’elle sert les intérêts matériels de l’humanité, mais encore en ce qu’elle aide notre intelligence à pénétrer dans les merveilles de la création qui nous entourent, et auxquelles se lient de la manière la plus intime notre existence, notre conservation et notre développement. » (Justus von Liebig, Lettres sur la Chimie, 1845) Crainte ou respectée, la Chimie ne laisse jamais indifférent. Elle innove, crée et réinvente la matière et sa transformation. Elle évolue sans cesse, s’adapte aux défis et aux changements qui lui sont imposés. Elle se fait « organique », « végétale », « métallurgique » ou « minérale » pour satisfaire les besoins matériels de notre existence. Elle devient « verte » pour minimiser son impact sur les générations futures. Si la chimie reste mystérieuse et complexe, elle devient cependant de plus en plus maitrisée et extrême. Doit-elle rompre avec ses traditions pour mieux s’intégrer dans notre futur ? Doit-elle se diversifier pour mieux se définir ? Est-elle multiple ou unique ? Souvent incomprise, elle ne demande cependant qu’à se faire connaître. [less ▲]

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See detailNutritional Composition and Rearing Potential of the Meadow Grasshopper (Chorthippus parallelus Zetterstedt)
Paul, Aman ULiege; Frederich, Michel ULiege; Uyttenbroeck, Roel ULiege et al

in Journal of Asia-Pacific Entomology (2016), 19(4), 1111-1116

Insects, particularly those belonging to the family Acrididae (grasshoppers), are commonly consumed as human food in many parts of the world. Grasshoppers of the species Chorthippus parallelus are ... [more ▼]

Insects, particularly those belonging to the family Acrididae (grasshoppers), are commonly consumed as human food in many parts of the world. Grasshoppers of the species Chorthippus parallelus are abundantly found throughout Europe. However, these insects were not consumed by Europeans till now, but could possibly be used as human food, which is why we investigated their chemical composition. We found that they contain high level of proteins (69%), with an excellent amino acid profile and protein digestibility (97%). Furthermore, specimens of C. parallelus have an interesting fatty acids profile and minerals composition. Preliminary toxicity assessment indicates that these insects do not exhibit toxicity towards neutrophil cells (white blood cells). These data suggest that C. parallelus could be considered for human consumption. Rearing trials done during the study show that commercial rearing could be developed to produce sufficient biomass for sustaining human consumption. [less ▲]

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See detailCola pierlotii R.Germ. : étude de la composition chimique de la graine
Lognay, Georges ULiege; Wathelet, Bernard ULiege; Maesen, Philippe ULiege

in Biotechnologie, Agronomie, Société et Environnement (2013), 17(2), 309-311

This note reports the first analysis of the chemical composition of Cola pierlotii seed. It compares the recorded values with various literature data on Cola nitida and Cola acuminata that are the two ... [more ▼]

This note reports the first analysis of the chemical composition of Cola pierlotii seed. It compares the recorded values with various literature data on Cola nitida and Cola acuminata that are the two most used species or as agent flavor or as a precursor drugs. Cola pierlotii is characterized in particular by a high caffeine content up to 1.27%. [less ▲]

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See detailThe relevance of food composition data for nutrition surveys in rural Tibet: pilot study in the context of Kashin-Beck Disease
DERMIENCE, Michael ULiege; Mathieu, Françoise; Barthelemy, Jean-Paul ULiege et al

in Biotechnologie, Agronomie, Société et Environnement (2013), 17(1), 32-42

Kashin-Beck disease (KBD) is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People’s Republic of China. The ... [more ▼]

Kashin-Beck disease (KBD) is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People’s Republic of China. The etiology of the disease remains obscure although environmental factors are assumed to be involved. Diet, in particular, differentiates the rural community, affected by KBD, from the other communities (nomads and city-dwellers), who remain unaffected. In anticipation of a nutrition survey, this study aimed to measure the mineral content (Ca, P, Mg, Fe, Zn, Mn, Cu, Ni, Se, Al, Sr, Mo, Cd, As, Pb, Hg, Cr, and Co) of eight Tibetan staple foods and to compare the results against two food composition tables (FCTs). Foods were sampled in twenty households selected from both an endemic and a non-endemic area of rural Tibet. Ten minerals involved in bone metabolism were measured using atomic and molecular spectrometric methods. Results revealed that a very limited number of food/constituent pairs showed a variation in mineral composition during a single year of testing for a given region. In addition, results showed significant differences in mineral content between the endemic and the non-endemic area, especially for wheat flour. Following our analysis of the mineral content of the Tibetan food samples, results were statistically compared with similar foods listed in two food composition tables: the USDA National Nutrient Database (USDA Food Search for Windows, Version 1.0, database version SR23), and the China Food Composition Table (book 1, 2nd edition). More than 50 to 60% of p-values < 0.05 were highlighted, suggesting the inappropriateness of using FCTs as a reference for nutrition surveys in rural Tibet, and emphasizing the need for analysis of traditional foods. Differences were found to be more or less marked depending on the element considered, and calcium content seemed to show the greatest difference. Although it is obviously too early for definite conclusions to be reached (insufficient number of samples by food and insufficient number of foods analyzed), it seems that the present pilot-study indicates significant discrepancies between measured and tabulated values of the mineral content of certain foods. A more complete survey would therefore seem mandatory. [less ▲]

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See detailComparison of mineral intake between children from endemic and non-endemic areas for Kashin-Beck disease in Tibet Autonomous Region: Pilote study
DERMIENCE, Michael ULiege; Maesen, Philippe ULiege; Mathieu, Françoise et al

Poster (2012, June 01)

Background The Kashin-Beck disease (KBD) is an endemic and chronic osteochondropathy affecting between 0.74 million and 2.5 million people in the Tibet Autonomous Region and in several provinces of the ... [more ▼]

Background The Kashin-Beck disease (KBD) is an endemic and chronic osteochondropathy affecting between 0.74 million and 2.5 million people in the Tibet Autonomous Region and in several provinces of the People’s Republic of China. The etiology remains unclear, although a multifactorial hypothesis has been proposed (selenium/iodine deficiency; high concentration of organic matters in drinking water; and mycotoxin poisoning by fungi infecting cereals). The rural population is almost exclusively affected. Objectives The first objective of this study was to assess and to compare the mineral daily intake between Tibetan preschool children living in endemic areas for the Kashin-Beck disease and those living in non-endemic areas. A second objective was the comparison of children daily intakes with Chinese Dietary Reference Intakes (DRIs). The third objective was to estimate a sample size for a cross-sectional survey aiming to highlight significant differences in mineral intakes between the two groups of preschool children. Materials and Methods Ten Tibetan preschool children were enrolled per group (endemic/non-endemic) for this pilot study. Children had to be weaned and those living in endemic area must have a KBD sibling. The nutrition survey consisted in an interactive simplified 24-hour recall questionnaire. Two 24-hour recalls were recorded for the endemic group, in February 2010 (EAw) and in May 2010 (EAs), while one day has been recorded for the non-endemic group in July 2011 (NEA). At the same time, samples of the main staple foods were collected for chemical analysis. The daily intakes of Ca, P, Mg, Fe, Zn, Cu, and Mn were calculated based on the 24-hour recall records, the chemical analyses, and data from food composition tables (FCTs). Results and discussion We are aware of limitations in the methodological approach of this pilot-study. The number of children, although weak, was empirically decided for the sake of feasibility and because no prior information was available. The interactive 24-hour recalls between the two groups are spaced in time. Nevertheless, the diet of rural Tibetans is far from diversified, and the variability among seasons and years is probably low. Daily intakes in Ca, P, Mg, Fe, Zn, Cu and Mn were calculated for children of each group. Parametric test were applied for comparison of mean daily intakes between groups. A significant difference was highlighted for Cu (p-value<0.01) and Fe (p-value<0.05), no other significant difference was detected. When comparing individual daily intakes and Chinese DRIs, the most striking results concern Ca and Mn. The great majority of children showed severe deficiency in calcium and enormous excess in manganese. A power (1-β) of 80% is commonly accepted when estimating a sample size for a cross-sectional survey. In this case, the maximum sample size is too high and not feasible in practice (several hundred children per group). Oppositely, the power was calculated per mineral, based on 100 children per group. The power is higher than 90% for Mg, Fe, and Cu. For the others minerals, the power is well below 80%. Nevertheless, general deficiencies and excesses have been observed in the two groups for part of these minerals. We believe that it is a statement in itself and trying to highlight small differences between groups in such extremes is not relevant. [less ▲]

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See detailEffect of harvest time on seed oil and protein contents and compositions in the oleaginous gourd Lagenaria siceria (Molina) Standl
Loukou, Ahou; Lognay, Georges ULiege; Barthelemy, Jean-Paul ULiege et al

in Journal of the Science of Food and Agriculture (2011), 91(11), 2073-2080

BACKGROUND: The stage of fruit ripeness at the time of harvest determines the final quality of ripe fruit. In this study, changes in the chemical composition of seed kernels from the oleaginous gourd ... [more ▼]

BACKGROUND: The stage of fruit ripeness at the time of harvest determines the final quality of ripe fruit. In this study, changes in the chemical composition of seed kernels from the oleaginous gourd Lagenaria siceraria (Molina) Standl. during maturation were evaluated to determine the best time to harvest the berries. Two cultivars (round and oval berry) were studied at three maturation stages (30 and 50 days after fruit set (DAFS) and complete plant whiteness (CPW)). [less ▲]

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See detailPotentialités d’application des technologies biologiques pour la depollution des sols en Wallonie
Aldric, Jean-Marc ULiege; Druart, P.; Maesen, Philippe ULiege et al

in Journal des Ingénieurs (2011), 132

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See detailKashin-Beck Disease: evaluation of mineral intake in young Tibetan children from endemic areas
DERMIENCE, Michael ULiege; Maesen, Philippe ULiege; Mathieu, Françoise et al

Poster (2010, October 26)

Kashin-Beck disease is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People’s Republic of China. Although many ... [more ▼]

Kashin-Beck disease is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People’s Republic of China. Although many studies have already been conducted and many others are still underway, its ethiology remains unknown. A multifactorial hypothesis has been proposed: selenium deficiency, high concentration of organic matters in drinking water (fulvic acids) and mycotoxin poisoning by fungi infecting cereals. This original study aimed to measure the mineral contents of the food most often consumed in severe endemic regions and then to evaluate the daily intake of minerals in young Tibetan children from endemic areas. The mineral elements were selected in relation to their implications in bone metabolism. A sampling campaign split up into two time periods (winter and spring) was carried out. Ten families from two distinct regions were selected based on three criteria: they live in endemic areas; they include a 3 to 5 year-old child; this child has a KBD brother or sister. At the same time, a nutritional survey was made by the means of a prospective questionnaire in order to list the 24h food intake of the 3 to 5 year-old child. This survey highlighted the extremely monotonous cereal-based Tibetan diet. An analytical method for the minerals was developed as follows: mineralization of samples performed by microwave-assisted wet process; mineralized solutions measured by several atomic absorption or emission spectrometric methods and molecular absorption spectrometric methods. The analytical method was validated by mean of certified reference materials. Mean food contents were calculated and compared to food composition reference tables. High iron contents and selenium deficiencies were highlighted in several foods. Daily intakes were estimated combining mineral measurements and nutritional survey results. These were compared to dietary reference intakes from reference tables. This estimation reveals some crucial points: we confirm a marked deficiency in calcium; Ca/P ratios are always low; iron and copper intakes are excessive; zinc is the most probably deficient; while selenium could be deficient; manganese intakes often exceed toxicity thresholds. Nevertheless, this study encounters some limits. The bioavailability of minerals is a critical point that deserves further investigations. Moreover, a larger study over a longer term covering both endemic and non-endemic regions is required for definite conclusions to be reached. [less ▲]

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See detailFactors influencing microbiological and chemical composition of South-Belgian raw sludge
Guillemet, Thibault A.; Maesen, Philippe ULiege; Delcarte, Emile et al

in Biotechnologie, Agronomie, Société et Environnement (2009), 13(2), 249-255

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See detailDéveloppement d'un système harmonisé de surveillance de la qualité des terres agricoles en Région wallonne anticipant la future directive européenne sur les sols
Warin, Arnaud; Bernaerdt, R.; Delcarte, Emile et al

in Biotechnologie, Agronomie, Société et Environnement (2004), 8(2), 69-83

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See detailMise en place de sites chantiers en vue de l'établissement d'un système harmonisé de surveillance de la qualité des terres cultivées en Région wallonne
Warin, Arnaud; Bernaerdt, R.; Delcarte, Emile et al

Report (2003)

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