Last 7 days     Results 461-480 of 35707.   19 20 21 22 23 24 25 26 27 28 29   How do harpacticoid copepods colonize detrital seagrass leaves?Mascart, Thibaud ; Agusto, Laura; Lepoint, Gilles et alin Marine Biology (in press)An experiment was carried out investigating the colonization ability and specific pattern of copepods towards a provisional benthic habitat. Since copepods are known to disperse passively and actively ... [more ▼]An experiment was carried out investigating the colonization ability and specific pattern of copepods towards a provisional benthic habitat. Since copepods are known to disperse passively and actively, the experiment aimed to investigate the pool of colonizers of macrophytodetritus and the species-specific active colonization pathways. The experiment was performed in a Mediterranean seagrass Posidonia oceanica meadow on defaunated macrophytodetritus accumulations (mainly dead seagrass leaves) for two time intervals (24 h and 96 h). Active colonization by copepods, independently of their adjacent potential source pool habitat (bare sandy sediments, P. oceanica canopy, water column and macrophytodetritus) occurred within 24 h. Natural densities (as in the control treatments) were only reached by active colonization through the water column. Both neither diversities nor species composition of natural macrophytodetritus were ever reached by one single migratory pathway, therefore only a combination of interstitial migration and water column migration can explain the species occurrence under natural condition. Moreover, every potential adjacent source pool habitat, contributed species to the newly colonized macrophytodetritus. However, the main colonizers were mostly species with good swimming capabilities. The diverse pool of species present in the newly colonized macrophytodetritus underlines the complex communities and dispersion capabilities of copepods. Hence, macrophytodetritus possesses the potential ability to be a colonizer source pool for every adjacent habitat and thus behaves as a copepod hub for the entire seagrass ecosystem. [less ▲]Detailed reference viewed: 11 (1 ULg) Another Generalization of Abelian Equivalence: Binomial Complexity of Infinite Words (long version)Rigo, Michel ; Salimov, Pavelin Theoretical Computer Science (in press)The binomial coefficient of two words $u$ and $v$ is the number of times $v$ occurs as a subsequence of $u$. Based on this classical notion, we introduce the $m$-binomial equivalence of two words refining ... [more ▼]The binomial coefficient of two words $u$ and $v$ is the number of times $v$ occurs as a subsequence of $u$. Based on this classical notion, we introduce the $m$-binomial equivalence of two words refining the abelian equivalence. Two words $x$ and $y$ are $m$-binomially equivalent, if, for all words $v$ of length at most $m$, the binomial coefficients of $x$ and $v$ and respectively, $y$ and $v$ are equal. The $m$-binomial complexity of an infinite word $x$ maps an integer $n$ to the number of $m$-binomial equivalence classes of factors of length $n$ occurring in $x$. We study the first properties of $m$-binomial equivalence. We compute the $m$-binomial complexity of two classes of words: Sturmian words and (pure) morphic words that are fixed points of Parikh-constant morphisms like the Thue--Morse word, i.e., images by the morphism of all the letters have the same Parikh vector. We prove that the frequency of each symbol of an infinite recurrent word with bounded $2$-binomial complexity is rational. [less ▲]Detailed reference viewed: 8 (0 ULg) Defining multiplication in some additive expansions of polynomial ringsPoint, Françoise; Rigo, Michel ; Waxweiler, Laurentin Communications in Algebra (in press)Adapting a result of R. Villemaire on expansions of Presburger arithmetic, we show how to define multiplication in some expansions of the additive reduct of certain Euclidean rings. In particular, this ... [more ▼]Adapting a result of R. Villemaire on expansions of Presburger arithmetic, we show how to define multiplication in some expansions of the additive reduct of certain Euclidean rings. In particular, this applies to polynomial rings over a finite field. [less ▲]Detailed reference viewed: 8 (1 ULg) An analogue of Cobham's theorem for graph directed iterated function systemsCharlier, Emilie ; Leroy, Julien ; Rigo, Michel in Advances in Mathematics (in press)Feng and Wang showed that two homogeneous iterated function systems in $\mathbb{R}$ with multiplicatively independent contraction ratios necessarily have different attractors. In this paper, we extend ... [more ▼]Feng and Wang showed that two homogeneous iterated function systems in $\mathbb{R}$ with multiplicatively independent contraction ratios necessarily have different attractors. In this paper, we extend this result to graph directed iterated function systems in $\mathbb{R}^n$ with contraction ratios that are of the form $\frac{1}{\beta}$, for integers $\beta$. By using a result of Boigelot {\em et al.}, this allows us to give a proof of a conjecture of Adamczewski and Bell. In doing so, we link the graph directed iterated function systems to Büchi automata. In particular, this link extends to real numbers $\beta$. We introduce a logical formalism that permits to characterize sets of $\mathbb{R}^n$ whose representations in base $\beta$ are recognized by some Büchi automata. This result depends on the algebraic properties of the base: $\beta$ being a Pisot or a Parry number. The main motivation of this work is to draw a general picture representing the different frameworks where an analogue of Cobham's theorem is known. [less ▲]Detailed reference viewed: 19 (5 ULg) Glioblastoma-derived extracellular vesicles induce tumor-supportive phenotypes in monocytic cellsde Vrij, Jeroen; Maas, Sybren; Kwappenberg, Kitty et alin International Journal of Cancer = Journal International du Cancer (in press)Detailed reference viewed: 5 (1 ULg) High Resolution postontrast time of flight MR angiography of intracranial perforators at 7.0 TeslaHarteveld, A; de Cocker, L; Dieleman, N et alin American Journal of Neuroradiology (in press)Detailed reference viewed: 4 (0 ULg) Fish consumption patterns and hair mercury levels in children and their mothers in 17 EU countriesCastano, Argelia; Cutanda, Francisco; Esteban, Marta et alin Environmental Research (in press)The toxicity of methylmercury (MeHg) in humans is well established and the main source of exposure is via the consumption of large marine fish and mammals. Of particular concern are the potential ... [more ▼]The toxicity of methylmercury (MeHg) in humans is well established and the main source of exposure is via the consumption of large marine fish and mammals. Of particular concern are the potential neurodevelopmental effects of early life exposure to low-​levels of MeHg. Therefore, it is important that pregnant women, children and women of childbearing age are, as far as possible, protected from MeHg exposure. Within the European project DEMOCOPHES, we have analyzed mercury (Hg) in hair in 1799 mother-​child pairs from 17 European countries using a strictly harmonized protocol for mercury anal. Parallel, harmonized questionnaires on dietary habits provided information on consumption patterns of fish and marine products. After hierarchical cluster anal. of consumption habits of the mother-​child pairs, the DEMOCOPHES cohort can be classified into two branches of approx. similar size: one with high fish consumption (H) and another with low consumption (L)​. All countries have representatives in both branches, but Belgium, Denmark, Spain, Portugal and Sweden have twice as many or more mother-​child pairs in H than in L. For Switzerland, Czech Republic, Hungary, Poland, Romania, Slovenia and Slovakia the situation is the opposite, with more representatives in L than H. There is a strong correlation (r=0.72) in hair mercury concn. between the mother and child in the same family, which indicates that they have a similar exposure situation. The clustering of mother-​child pairs on basis of their fish consumption revealed some interesting patterns. One is that for the same sea fish consumption, other food items of marine origin, like seafood products or shellfish contribute significantly to the mercury levels in hair. We conclude that addnl. studies are needed to assess and quantify exposure to mercury from seafood products, in particular. The cluster anal. also showed that 95​% of mothers who consume once per wk fish only, and no other marine products, have mercury levels 0.55 μg​/g. Thus, the 95th percentile of the distribution in this group is only around half the US-​EPA recommended threshold of 1 μg​/g mercury in hair. Consumption of freshwater fish played a minor role in contributing to mercury exposure in the studied cohort. The DEMOCOPHES data shows that there are significant differences in MeHg exposure across the EU and that exposure is highly correlated with consumption of fish and marine products. Fish and marine products are key components of a healthy human diet and are important both traditionally and culturally in many parts of Europe. Therefore, the communication of the potential risks of mercury exposure needs to be carefully balanced to take into account traditional and cultural values as well as the potential health benefits from fish consumption. European harmonized human biomonitoring programs provide an addnl. dimension to national HMB programs and can assist national authorities to tailor mitigation and adaptation strategies (dietary advice, risk communication, etc.) to their country's specific requirements. [less ▲]Detailed reference viewed: 69 (16 ULg) Éclairer les enjeux de la reconstruction industrielle du bassin liégeois : l'apport des archives des Etablissements insalubres et dangereux (1919-1925)Peters, Arnaud ; Defechereux, Olivier ; Destatte, Julien in Parmentier, Isabelle (Ed.) Actes des Deuxièmes Rencontres d'Histoire de l'Environnement en Belgique (Belgique, Luxembourg, Congo, Rwanda, Burundi) (in press)Detailed reference viewed: 36 (17 ULg) The utility of Google Scholar when searching geographical literature: comparison with three commercial bibliographic databasesStirbu, Simona ; Thirion, Paul ; Schmitz, Serge et alin Journal of Academic Librarianship (in press)This study aims to highlight what benefits, if any, Google Scholar (GS) has for academic literature searches in the field of geography, compared to three commercial bibliographic databases: Web of Science ... [more ▼]This study aims to highlight what benefits, if any, Google Scholar (GS) has for academic literature searches in the field of geography, compared to three commercial bibliographic databases: Web of Science (WoS) and FRANCIS (multidisciplinary databases) and GeoRef (specialized in geosciences). To ensure a valid comparison, identical bibliographic searches were applied using each of the four bibliographic tools. To exclude automatic variations of the ten keywords tested, they were placed between quotation marks and searched only in the “title” field of the respective search tools’ interfaces. The results were limited to bibliographic references published from 2005 to 2009. In order to assess the repeatability of the results, the exact same process was repeated monthly between November 2010 and July 2011. Initially the whole set of results was analyzed, after which the search results for two keywords (selected since they yielded a manageable number of results) were studied in more detail. The results indicate that GS search results show a large degree of overlap with those of the other databases but, moreover, yield numerous unique hits, which should be useful to researchers in both the fields of human and physical geography. GS leads the other tools widely on number of results, independently of keyword, subfield, year of publication, or time of search. [less ▲]Detailed reference viewed: 79 (36 ULg) Using kernels and ecological niche modelling to delineate conservation areas in an endangered patch-breeding phenotypeDenoël, Mathieu ; Ficetola, Francescoin Ecological Applications (in press)Efficient delineation of conservation areas is a great challenge in maintaining biodiversity. Kernel density estimators (KDEs) are a powerful tool in this perspective, but they have not been applied at ... [more ▼]Efficient delineation of conservation areas is a great challenge in maintaining biodiversity. Kernel density estimators (KDEs) are a powerful tool in this perspective, but they have not been applied at the population level on patch-distributed organisms. This would be particularly worthy for species that need broad habitats beyond those where they can be sampled; such as terrestrial lands for pond-breeding amphibians. The aim of this study was to compare different approaches for the identification of suitable areas for conservation: KDE, ecological niche modelling, and a combination of KDE and niche models. Paedomorphosis was chosen as a model system because this is an important form of intraspecific variation that is present in numerous taxa, but geographically localized within species and globally endangered. 277 ponds were sampled in one of the hotspots of paedomorphosis to determine the abundance and distribution of paedomorphs (i.e. individuals retaining gills at the adult stage) of the palmate newt (Lissotriton helveticus), with emphasis on the connections between the most valuable populations. KDEs gave insights into the surface areas required to balance the maintenance of certain number of connected ponds and the respective number of disjoint areas in which the whole population is divided. The inclusion of barriers in the models helped in accurately designing the limits of the areas to protect. Alone, habitat models were not able to successfully delineate the area to protect, but the integration between terrestrial suitable areas or barriers and KDE allowed an objective identification of areas required for conservation. Overall, the best performance was observed by the KDE integrating ecological barriers, and by the combination between KDE and niche modelling. In a broader perspective, KDEs are thus a pertinent tool in providing quantitative spatial measurements to delineate conservation areas based on patch-abundance data with a specific focus to connectivity. [less ▲]Detailed reference viewed: 34 (17 ULg) Moyens et enjeux d’une approche didactique des IlluminationsSaint-Amand, Denis in Parade Sauvage (in press), 25Detailed reference viewed: 22 (4 ULg) Towards a framework for assessment and management of cumulative human impacts on marine food websGiakoumi, Sylvaine; Halpern, Benjamin S.; Michel, Loïc et alin Conservation Biology (in press)Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic ... [more ▼]Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the food web components, and assessed the components’ vulnerability to those threats. Some threats had high (e.g., coastal infrastructure) or low impacts (e.g., agricultural runoff) on all food web components, whereas others (e.g., introduced carnivores) had very different impacts on each component. Partitioning the ecosystem into its components enabled us to identify threats previously overlooked and to reevaluate the importance of threats commonly perceived as major. By incorporating this understanding of system vulnerability with data on changes in the state of each threat (e.g., decreasing domestic pollution and increasing fishing) into a food web model, managers may be better able to estimate and predict cumulative human impacts on ecosystems and to prioritize conservation actions. [less ▲]Detailed reference viewed: 24 (5 ULg) Comments on the discordant recommendations for the use of symptomatic slow acting drugs in knee osteoarthritis.Reginster, Jean-Yves ; Cooper, Cyrus; Hochberg, Marc et alin Current medical research and opinion (in press)Abstract Despite the near concurrent publication by influential scientific organizations, there are important differences in interpretation of the evidence base and the conclusions derived from the recent ... [more ▼]Abstract Despite the near concurrent publication by influential scientific organizations, there are important differences in interpretation of the evidence base and the conclusions derived from the recent Osteoarthritis Research Society International (OARSI) guidelines for the management of knee osteoarthritis, the American College of Rheumatology (ACR) (concerning also hip and hand osteoarthritis) and the algorithm recommendations by the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). This is particularly evident for the drug class of Symptomatic Slow-Acting Drugs in OsteoArthritis. In this paper, we highlight these differences and try to understand where they derive from, proposing an evidence-based interpretation. [less ▲]Detailed reference viewed: 9 (3 ULg) Le Mur et le masque. À propos de Banksy.Saint-Amand, Denis in MethIS : Méthodes et Interdisciplinarité en Sciences Humaines (in press)Detailed reference viewed: 44 (8 ULg) A Parallel Processing Approach to Dynamic Simulations of Combined Transmission and Distribution SystemsAristidou, Petros ; Van Cutsem, Thierry in International Journal of Electrical Power & Energy Systems (in press)Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, a Schur-complement-based domain decomposition algorithm is ... [more ▼]Simulating a power system with both transmission and distribution networks modeled in detail is a huge computational challenge. In this paper, a Schur-complement-based domain decomposition algorithm is proposed to provide accurate, detailed dynamic simulations of such systems. The simulation procedure is accelerated with the use of parallel programming techniques, taking advantage of the parallelization opportunities inherent to domain decomposition algorithms. The proposed algorithm is general, portable and scalable on inexpensive, shared-memory, multi-core machines. A large-scale test system is used for its performance evaluation. [less ▲]Detailed reference viewed: 20 (7 ULg) À propos de l’écologie du discours heuristiqueJob, Pierre ; Gilot, Marguerite in Actes du 4ième congrès international sur la théorie anthropologique du didactique (TAD) : Évolutions contemporaines du rapport aux mathématiques et aux autres savoirs à l'école et dans la société (in press)Detailed reference viewed: 9 (1 ULg) Inventer. Le jeune Descartes et les voies de l’inventio en 1619-1620Dubouclez, Olivier in Savini, Massimiliano (Ed.) Les écrits de jeunesse de Descartes (in press)Detailed reference viewed: 14 (2 ULg) Imaginer-lire le CapitalPieron, Julien in Cahiers d'Etudes Germaniques (in press)Detailed reference viewed: 11 (0 ULg) Dialectique de l’inattendu. Voies et impasses de la philosophie dans l’œuvre de Valère NovarinaDubouclez, Olivier in Née, Laure (Ed.) Valère Novarina (in press)Novarina entretient avec la philosophie une relation faite d’attraction et de défiance. Le primat accordé à la parole et le refus de toute ontologie le conduisent à définir un nouveau modèle théorique ... [more ▼]Novarina entretient avec la philosophie une relation faite d’attraction et de défiance. Le primat accordé à la parole et le refus de toute ontologie le conduisent à définir un nouveau modèle théorique, celui de la « fugue » et, tout en poursuivant le dialogue avec les philosophes, à construire ce que nous appellerons une dialectique de l’inattendu, mouvement par lequel le vide actif qui habite la personne humaine nourrit le renouvellement de la pensée et de l’action. [less ▲]Detailed reference viewed: 14 (2 ULg) Compte rendu de l'ouvrage de Cl. Prêtre, "Kosmos et kosmema. Les offrandes de parure dans les inventaires déliants"Veymiers, Richard in Revue archéologique (in press)Detailed reference viewed: 27 (1 ULg)