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See detailImpact of food type on respiration, fractionation and turnover of carbon and nitrogen stable isotopes in the marine amphipod Gammarus aequicauda (Martynov, 1931).
Remy, François ULg; Darchambeau, François ULg; Melchior, Aurélie et al

in Journal of Experimental Marine Biology & Ecology (2017), 486

This study experimentally determined the impact of food source type on turnover rate and trophic enrichment factors (TEFs or ∆) of δ13C and δ15N, as well as on respiration rate, in captive populations of ... [more ▼]

This study experimentally determined the impact of food source type on turnover rate and trophic enrichment factors (TEFs or ∆) of δ13C and δ15N, as well as on respiration rate, in captive populations of the marine amphipod Gammarus aequicauda. Gammarus aequicauda (318 individuals) were fed ad libitum with three food sources animal, algae, and dead Posidonia oceanica leaves (also called “litter”), varying in palatability, digestibility, nutritional qualities and isotopic compositions, for between four and six weeks in a controlled feeding experiment. The resulting death rate was lower for the amphipods fed with animal treatment (30.9%) than for individuals fed with algal (65.9%) or litter treatment (64.4%), indicating a better fitness of the individuals fed with the animal food source. Respiration rates also differed highly among the treatments. Animal treatment showed higher respiration rates than algal and litter treatments, potentially due to the toxicity of the algae and the very low nutritional quality of the litter. Amphipods fed with these treatments might have entered in a “low activity state” to cope with these unsuitable food sources, inducing low respiration rates. Due to the very low assimilation and toxicity of the algae source, turnover rate for δ13C was impossible to determine. Turnover rate for δ13C was much faster (half-life = 12.55 days) for amphipods fed with the animal food source than for amphipods fed with litter (half-life = 51.62 days), showing the faster assimilation of the most nutritionally optimal food sources by G. aequicauda. Turnover for δ15N was impossible to determine because the amphipods were already at isotopic equilibrium at the beginning of the experiment. Despite the detritus feeder status of Gammarus aequicauda, TEFs for the animal treatments were in accordance with values generally found for carnivorous organisms (∆13C = 0.9 ± 0.7‰; ∆15N = 2.9 ± 0.6‰). TEFs for the litter treatment were in accordance with values generally corresponding to detritivorous organisms (∆13C = 1.2‰; ∆15N = 1.0 ± 0.4‰). SIAR mixing model outputs obtained with these new TEF values were more constrained and coherent than outputs obtained with general literature TEFs. This study thus demonstrated the non-negligible impact of the food source on Gammarus aequicauda physiological status, fitness and turnover rates, but also on TEFs—highlighting the importance of TEF experimental calculations for every potential food source of a given organism to ensure more robust isotopic data interpretation. [less ▲]

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See detailQuelques idées générales à propos de la compréhension en mathématiques
Bair, Jacques ULg

E-print/Working paper (2017)

Dans cet article, nous apportons des éléments de réponse à la question générale suivante : "Que signifie bien comprendre en mathématiques ?" Nous nous demandons pourquoi il est difficile d'y répondre et ... [more ▼]

Dans cet article, nous apportons des éléments de réponse à la question générale suivante : "Que signifie bien comprendre en mathématiques ?" Nous nous demandons pourquoi il est difficile d'y répondre et apportons une piste de solution en distinguant les activités de production de celles de reproduction. De plus, nous abordons le problème étudié d'un point de vue aussi bien local que global. Enfin, nous nous interrogeons sur l'incompréhension en mathématiques en proposant une typologie, en repérant des causes possibles d'incompréhension et en donnant quelques conseils pratiques. [less ▲]

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See detailAttention et simultanéité intellectuelle chez Descartes, Clauberg et Spinoza
Dubouclez, Olivier ULg

in Les études philosophiques (2017), 1

Abstract. – is paper deals with a classical problem, can we think or apprehend many things at once ? as it was understood and solved by Descartes and its followers. e idea that we can apprehend di erent ... [more ▼]

Abstract. – is paper deals with a classical problem, can we think or apprehend many things at once ? as it was understood and solved by Descartes and its followers. e idea that we can apprehend di erent ideas at once is central in Descartes’ theory of knowledge, especially in the Rules, and it relies on the claim that attention can be divided between two objects or ideas. Clauberg considers on the contrary that the imagination alone can graps things simultaneously and holds the living body as the true paradigm of simultaneous activity. Spinoza has a synthetic point of view : simultaneity within the body and the mind are expressions of the power of the individ- ual and of his develoment. Attention is no more a condition of intellectual simultaneity, as in Descartes, but is rather an obstacle which needs to be overcome to reach a richer and better understanding of reality. [less ▲]

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See detailLinking pollutant exposure of humpback whales breeding in the Indian Ocean to their feeding habits and feeding areas off Antarctica
Das, Krishna ULg; Malarvannan, Govindan; Dirtu, Alin et al

in Environmental Pollution (2017), 220

Humpback whales, Megaptera novaeangliae, breeding off la Reunion Island (Indian Ocean) undergo large-scale seasonal migrations between summer feeding grounds near Antarctica and their reproductive winter ... [more ▼]

Humpback whales, Megaptera novaeangliae, breeding off la Reunion Island (Indian Ocean) undergo large-scale seasonal migrations between summer feeding grounds near Antarctica and their reproductive winter grounds in the Indian Ocean. The main scope of the current study was to investigate chemical exposure of humpback whales breeding in the Indian Ocean by providing the first published data on this breeding stock concerning persistent organic pollutants (POPs), namely polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), DDT and its metabolites (DDTs), chlordane compounds (CHLs), polybrominated diphenyl ethers (PBDEs), and methoxylated PBDEs (MeO-PBDEs). Analyses of stable isotopes δ13C and δ15N in skin resulted in further insight in their feeding ecology, which was in agreement with a diet focused mainly on low trophic level prey species, such as krill from Antarctica. POPs were measured in all humpback whales in the order of HCB > DDTs > CHLs > HCHs > PCBs > PBDEs > MeO-BDEs. HCB (median: 24 ng.g-1 lw) and DDTs (median: 7.7 ng.g-1 lw) were the predominant compounds in all whale biopsies. Among DDT compounds, p,p’-DDE was the major organohalogenated pollutant, reflecting its long-term accumulation in humpback whales. Significantly lower concentrations of HCB and DDTs were found in females than in males (p<0.001). Other compounds were similar between the two genders (p>0.05). Differences in the HCB and DDTs suggested gender-specific transfer of some compounds to the offspring. POP concentrations were lower than previously reported results for humpback whales sampled near the Antarctic Peninsula, suggesting potential influence of their nutritional status and may indicate different exposures of the whales according to their feeding zones. Further investigations are required to assess exposure of southern humpback whales throughout their feeding zones. [less ▲]

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See detailSpatial variation in the accumulation of POPs and mercury in bottlenose dolphins of the Lower Florida Keys and the coastal Everglades (South Florida)
Damseaux, France ULg; Kiszka, J.; Heithaus, M.R. et al

in Environmental Pollution (2017), 220

The bottlenose dolphin (Tursiops truncatus) is an upper trophic level predator and the most common cetacean species found in nearshore waters of southern Florida, including the Lower Florida Keys (LFK ... [more ▼]

The bottlenose dolphin (Tursiops truncatus) is an upper trophic level predator and the most common cetacean species found in nearshore waters of southern Florida, including the Lower Florida Keys (LFK) and the Florida Coastal Everglades (FCE). The objective of this study was to assess contamination levels of total mercury (T-Hg) in skin and persistent organic pollutants (PCBs, PBDEs, DDXs, HCHs, HCB, Σ PCDD/Fs and Σ DL-PCBs) in blubber samples of bottlenose dolphins from LFK (n = 27) and FCE (n = 24). PCBs were the major class of compounds found in bottlenose dolphin blubber and were higher in individuals from LFK (Σ 6 PCBs LFK males: 13421 ± 7730 ng.g-1 lipids, Σ 6 PCBs LFK females: 9683 ± 19007 ng.g-1 lipids) than from FCE (Σ 6 PCBs FCE males: 5638 ng.g-1 ± 3627 lipids, Σ 6 PCBs FCE females: 1427 ± 908 ng.g-1 lipids). These levels were lower than previously published data from the southeastern USA. The Σ DL-PCBs were the most prevalent pollutants of dioxin and dioxin like compounds (Σ DL-PCBs LFK: 739 ng.g-1 lipids, Σ DL-PCBs FCE: 183 ng.g-1 lipids) since PCDD/F concentrations were low for both locations (mean 0.1 ng.g-1 lipids for LFK and FCE dolphins). The toxicity equivalences of PCDD/Fs and DL-PCBs expressed as TEQ in LFK and FCE dolphins is mainly expressed by DL-PCBs (81% LFK - 65% FCE). T-Hg concentrations in skin were significantly higher in FCE (FCE median 9314 ng.g-1 dw) compared to LFK dolphins (LFK median 2941 ng.g-1 dw). These bottlenose dolphins concentrations are the highest recorded in the southeastern USA, and may be explained, at least partially, by the biogeochemistry of the Everglades and mangrove sedimentary habitats that create favourable conditions for the retention of mercury and make it available at high concentrations for aquatic predators. [less ▲]

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See detailGREDOR. Outcomes and recommendations
Cornélusse, Bertrand ULg; Ernst, Damien ULg

Report (2017)

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See detailRelativité générale
De Rop, Yves ULg

Learning material (2017)

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See detailVous êtes formidables
RADERMECKER, Régis ULg

in Revue de l'Association Belge du Diabète (2017), 60

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See detailLe concept de duration : une présentation heuristique
Bair, Jacques ULg

Learning material (2017)

La duration est fondamentale en mathématiques financières. Nous la présentons de deux manières complémentaires qui sont qualifiées de classique et d’heuristique. La seconde méthode nous paraît originale et ... [more ▼]

La duration est fondamentale en mathématiques financières. Nous la présentons de deux manières complémentaires qui sont qualifiées de classique et d’heuristique. La seconde méthode nous paraît originale et bien adaptée pour amener les étudiants à effectuer un travail de recherche sur un problème concret et pour appliquer de nombreux concepts classiquement enseignés dans les programmes de mathématiques. [less ▲]

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See detailHabitat selection and reproduction of newts in networks of fish and fishless aquatic patches
Winandy, Laurane ULg; Legrand, Pauline ULg; Denoël, Mathieu ULg

in Animal Behaviour (2017), 123

The spatial distribution of organisms in patchy environments can be determined by the relationship between habitat quality and animal behaviour. In species with complex life cycles, such as pond-breeding ... [more ▼]

The spatial distribution of organisms in patchy environments can be determined by the relationship between habitat quality and animal behaviour. In species with complex life cycles, such as pond-breeding amphibians, the selection of a suitable wetland is crucial. While the traditional view of amphibian ecology suggests strong site fidelity and low vagility, more recent research highlights mechanisms involving active site choice through avoidance behaviour and bet-hedging strategies in heterogeneous environments. The introduction of fish to the aquatic environment is one of the factors that may alter site selection and lead to local dispersal. In this context, we investigated the habitat choice of Alpine newts, Ichthyosaura alpestris, in networks of fish (Carassius auratus) and fishless aquatic patches. Using a laboratory design consisting of aquaria divided into two water tanks connected by a terrestrial platform, we assessed newt distribution and movement between patches. During the breeding period, we compared the reproductive success of individuals in two types of networks. We found that newts escaped fish by rapidly changing aquatic patches and then aggregating in safe aquatic patches that were free of fish. In the fish network, newts maintained reproduction, but the high local abundance resulted in decreased sexual activity and egg production and increased use of the terrestrial habitat. However, in the fishless network, newts moved between aquatic patches several times, exhibited more courtship behaviour and laid more eggs than they did in the fish networks. Our results showed both adaptive habitat switching due to environmental risks in the fish network and habitat supplementation (i.e. use of alternative resources) in the fishless network. Such studies on movement behaviour and habitat selection have conservation implications in showing that the persistence of native species in invaded networks depends on the rescue effect, with immigration to fish-free habitats potentially preventing local extinction. [less ▲]

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See detailBioclimatism in Architecture : an evolutionary perspective
Nguyen, Anh Tuan; Reiter, Sigrid ULg

in International Journal of Design and Nature and Ecodynamics (2017), 12(1), 16-29

Fundamentals of vernacular architecture have been used in bioclimatic architecture which has gradually become the inspiration of various movements in contemporary architecture. The study points out that ... [more ▼]

Fundamentals of vernacular architecture have been used in bioclimatic architecture which has gradually become the inspiration of various movements in contemporary architecture. The study points out that the development of bioclimatism in architecture has followed the pattern of a natural evolutionary process in which “natural selection” is likely motivated by several factors, including resources and environment problems, and driven by different mechanisms including novel building design concepts and methods, new standards and codes, discoveries in building science and construction costs. This study is an effort aimed to clarify the evolution process of the bioclimatic approach in architecture over time and its influences on contemporary movements in architecture. The paper shows also that the evolutionary theory generated new scientific tools able to improve building design thanks to simulation-based optimization methods applied to building performances. Finally, this study investigates new motivations in the era of climate change whose effects are expected to introduce more challenges as well as more trends towards a sustainable built environment through the new concept of Eco-adaptive architecture. [less ▲]

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See detailHow does forest cover impact water flows and ecosystem services? Insights from real-life catchments in Wallonia (Belgium)
Brogna, Delphine; Vincke, Caroline; Brostaux, Yves ULg et al

in Ecological Indicators (2017), 72

While planet boundaries are being crossed and ecosystems degraded, the Ecosystem Service (ES) conceptrepresents a potential decision-making tool for improved natural resources management. The main aimof ... [more ▼]

While planet boundaries are being crossed and ecosystems degraded, the Ecosystem Service (ES) conceptrepresents a potential decision-making tool for improved natural resources management. The main aimof this paper is to assess the impact of forest cover on water related ES in Wallonia (Belgium) in termsof quantity and timing. We developed an approach based on easily accessible data, monitored in severalcountries and using straightforward statistical methods. This led us to study ES at “real-life” catchmentsscale: 22 catchments – from 30 to 250 km2– with mixed land covers were studied. We approached thewater supply and flood protection services through 5 indicators extracted from 10 hydrological years(2005–2014) discharge data series. These were computed annually and seasonally (vegetation periodfrom March to September and “non-vegetation” period the rest of the year). The water supply wasassessed through the specific volume Vs, the baseflow index BFI and the specific discharge exceeded95% of the time Q95s whereas the flood protection service was approached through the specific dis-charge exceeded 5% of the time Q05s and the flashiness index FI. Our study gives two main insights. First,statistical analyses show that forest cover negatively impact water supply when studying annual and“non-vegetation” period flows in general (Vs) but positively when studying low flows (Q95s). Regardingflood protection a slightly negative impact of forest cover on high flows (Q05s) was highlighted in the“non-vegetation” period. Results also show a negative impact of forests annually and in the vegetationperiod on the flashy behaviour of the catchment thus a positive impact on the flood protection ES. The“year” effect is overall highly significant testifying the importance of climatic factors. Rainfall is oftensignificant and can be considered as a main driver of these ES. Secondly, analyzing the quality of themodels produced and the results overall we assume that other variables characterizing the catchmentssuch as topography or soil types do play a significant role in the delivery of these ES. This questions theuse of land cover proxies in assessing and mapping of hydrological ES at a complex landscape scale. Wethus recommend further research to keep improving land cover proxies if they are used. [less ▲]

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See detailGenomic Studies of Multiple Myeloma Reveal an Association between X Chromosome Alterations and Genomic Profile Complexity.
Sticca, Tiberio ULg; CABERG, Jean-Hubert ULg; Wenric, Stéphane ULg et al

in Genes, Chromosomes & Cancer (2017)

The genomic profile of multiple myeloma (MM) has prognostic value by dividing patients into a good prognosis hyperdiploid group and a bad prognosis non-hyperdiploid group with a higher incidence of IgH ... [more ▼]

The genomic profile of multiple myeloma (MM) has prognostic value by dividing patients into a good prognosis hyperdiploid group and a bad prognosis non-hyperdiploid group with a higher incidence of IgH translocations. This classification, however, is inadequate and many other parameters like mutations, epigenetic modifications and genomic heterogeneity may influence the prognosis. We performed a genomic study by array-based comparative genomic hybridization (aCGH) on a cohort of 162 patients to evaluate the frequency of genomic gains and losses. We identified a high frequency of X chromosome alterations leading to partial Xq duplication, often associated with Xi deletion in female patients. This partial X duplication could be a cytogenetic marker of aneuploidy as it is correlated with a high number of chromosomal breakages. Patient with high level of chromosomal breakage had reduced survival regardless the region implicated. A higher transcriptional level was shown for genes with potential implication in cancer and located in this altered region. Among these genes, IKBKG and IRAK1 are members of the NFKB pathway which plays an important role in MM and is a target for specific treatments. [less ▲]

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See detailSartre in Venedig: der Mann, der in die Kälte ging
Cormann, Grégory ULg; Viehöver, Vera ULg

in Bulletin d'Analyse Phénoménologique (2017), 11

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See detailDroit matériel européen - recueil de documentation
Van Cleynenbreugel, Pieter ULg

Learning material (2017)

This set of cases and materials contains the key judgments and legislative instruments discussed in the compulsory droit matériel européen course. Judgments are preceded by self-study questions aimed at ... [more ▼]

This set of cases and materials contains the key judgments and legislative instruments discussed in the compulsory droit matériel européen course. Judgments are preceded by self-study questions aimed at facilitating one's understanding of the legal reasoning underlying them. [less ▲]

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See detailDEVELOPMENT OF ANALYTICAL TOOLS FOR THE DETERMINATION OF MARKERS OF LIPID ALTERATION IN FOOD
Douny, Caroline ULg

Doctoral thesis (2017)

It is now well-known that n-3 polyunsaturated fatty acids (omega-3 PUFA) have beneficial effects on health but are also rapidly oxidized in potentially toxic compounds, which means that healthy food ... [more ▼]

It is now well-known that n-3 polyunsaturated fatty acids (omega-3 PUFA) have beneficial effects on health but are also rapidly oxidized in potentially toxic compounds, which means that healthy food products, rich in n-3 PUFA, can become toxic for the consumer if not stored or processed appropriately. The main objective of this work was to develop new analytical tools to study markers of lipids alteration in food, in order to allow an adequate monitoring of possible toxic compounds in n-3 PUFA rich food products. The first chapter of this PhD thesis is a literature review about fatty acids, their oxidation and the different oxidation products generated. The different analytical techniques used to study the oxidative stability of polyunsaturated fatty acids and their degradation products in food are also described. Chapter 2 describes the development of a gas chromatography coupled to mass spectrometry (GC-MS) method to analyze the fatty acids in food. The method was applied to eggs and pork (both standard and n-3 enriched) submitted to various cooking processes and storage conditions. This study confirmed that the fat of standard eggs or pork from the Belgian market cannot be considered as a source ofn-3 PUFA.. Indeed, in this work, we measured no n-3 PUFA in meat or only around 2 % for eggs, while the fat of both enriched eggs and pork contained about 10 % of n-3 fatty acids. After storage or cooking without culinary fat no change of the fatty acid profile was observed, in standard eggs or pork. We made the same observation for n-3 enriched products, except for some cooking processes (pan-frying and oven cooking), which induced a slight but significant loss of n-3 fatty acids in n-3 enriched eggs or pork. The fairly stable behavior of the fatty acids after various cooking and storage experiments indicates that the fatty acid profile is not a good marker of lipid alteration. As a consequence, this work was oriented to the development of analytical tools to evaluate the presence of toxic aldehydes in food and feed as secondary oxidation products coming from polyunsaturated fatty acids. Chapter 3 is dedicated to the study of the oxidative stability of linseed oil, an oil rich in n-3 fatty acids. Section 3.1 describes the development of a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method to evaluate the aldehyde content in linseed oil. After optimisation of the extraction, derivation, detection and quantification steps, the method was validated according to guidelines from the European legislation as well as the recommendations of the AFNOR protocol NF V 03-110 (AFNOR, 2010). The evaluated parameters included specificity/selectivity, recovery, precision, accuracy, uncertainty, limits of detection and quantification, determined using the concept of accuracy profiles. When the method was applied to first pressure linseed oil stored for several days at 60 °C according to the Schaal oven test, it was shown that 4-hydroxy-2E-hexenal (4-HHE) was the most produced aldehyde. In Section 3.2, the different patterns of oxidation of linseed oil in real-time and accelerated aging assays were investigated, in order to verify the hypothesis commonly accepted for vegetal oil that one day aging at 60 °C is equivalent to one month real time aging at room temperature. Oxidation was evaluated with the peroxide value and para-anisidine value, as well as the content in conjugated dienes and aldehydes. All four indicators of oxidation showed very different kinetic behaviours at 20 and 60 °C, showing that the hypothesis (1 day at 60 °C = 1 month at 20 °C) is not valid for linseed oil. Chapter 4 describes the adaptation and the validation of a LC-MS/MS method to determine aldehydes in animal feed samples. Indeed, as animal feed is often enriched with linseed to increase the human intake of n-3 fatty acids through the consumption of food from animal origin, the study of the oxidative stability of n-3 enriched animal feed is also of interest. To achieve that goal, the LC-MS/MS method previously developed for linseed oil was adapted to include more aldehydes and was validated using the same guidelines as in section 3.1. Finally, chapter 5 presents the discussion and conclusions about the developed methods and the results obtained as well as their comparison with literature. Future prospects to improve the evaluation of and the exposure to the markers of lipid alteration in food are proposed. [less ▲]

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See detailDancing without listening to the music: learning from some failures of the ‘national innovation systems’ in Latin America
Delvenne, Pierre ULg; Thoreau, François ULg

in Kuhlmann, Stefan; Ordóñez-Matamoros, Gonzalo (Eds.) Research Handbook on Innovation Governance for Emerging Economies (2017)

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