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See detailDual methods for optimizing finite element flexural systems
Fleury, Claude ULg; Sander, G.

in Computer Methods in Applied Mechanics & Engineering (1983), 37(3), 249-275

Modern numerical methods for the optimization of large discretized systems are now well developed and highly efficient in the case of thin walled elastic structures modeled by finite elements. However ... [more ▼]

Modern numerical methods for the optimization of large discretized systems are now well developed and highly efficient in the case of thin walled elastic structures modeled by finite elements. However, this is not yet true for structures whose components are subject simultaneously to bending and extension loads. In this paper, the idea of Generalized Optimality Criterion (GOC), set forth in previous papers for bar, membrane, and pure bending elements, is extended to deal with general beam and flat shell elements. The modifications brought to the GOC result in explicit approximations for the behavior constraints that are correct up to the first order, but that exhibit a more complex algebraic form. Indeed these explicit expressions are no longer merely linear in the reciprocal design variables. However, they continue to be additively separable, and therefore dual methods remain fully applicable, just as in the original statement of the GOC approach. Numerical examples will be offered to demonstrate the efficiency of the method presented. [less ▲]

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See detailDual Multimodular Class a Penicillin-Binding Proteins in Mycobacterium Leprae
Lepage, Sophie; Dubois, Philippe ULg; Ghosh, Thushar-Kanti et al

in Journal of Bacteriology (1997), 179(14), 4627-4630

The ponA gene of cosmid L222 of the Mycobacterium leprae genome library encodes a multimodular class A penicillin-binding protein (PBP), PBP1. The PBP, labelled with a polyhistidine sequence, has been ... [more ▼]

The ponA gene of cosmid L222 of the Mycobacterium leprae genome library encodes a multimodular class A penicillin-binding protein (PBP), PBP1. The PBP, labelled with a polyhistidine sequence, has been produced in Escherichia coli, extracted from the membranes with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propane-sulfonate (CHAPS) and purified by Ni2(+)-nitrilotriacetic acid-agarose chromatography. In contrast to the pon1-encoded class A PBP1, PBP1 undergoes denaturation at temperatures higher than 25 degrees C, it catalyzes acyl transfer reactions on properly structured thiolesters, and it binds penicillin with high affinity. [less ▲]

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See detailDual origin of Fe-Ti-P gabbros by immiscibility and fractional crystallization of evolved tholeiitic basalts in the Sept Iles layered intrusion
Namur, O.; Charlier, Bernard ULg; Holness, M. B.

in Lithos (2012), 154

We present a detailed study of two ca. 200m-thick apatite-bearing ferrogabbro horizons of the Sept Iles layered intrusion (Canada). These rocks are the most evolved cumulates of the megacyclic units (MCU ... [more ▼]

We present a detailed study of two ca. 200m-thick apatite-bearing ferrogabbro horizons of the Sept Iles layered intrusion (Canada). These rocks are the most evolved cumulates of the megacyclic units (MCU) I and II, and mark the transition between basaltic and silicic magmatism. They are made up of plagioclase (An 55-34), olivine (Fo 66-21), clinopyroxene (Mg#75-55), ilmenite, magnetite, apatite, ±pigeonite and are a significant source of Fe-Ti-P ore. Ferrogabbros have relatively uniform bulk-rock compositions in MCU I but are bimodal in MCU II. The liquid lines of descent for major elements in equilibrium with cumulates of MCU I and II have been calculated using a forward model formalism. Both trends evolve towards SiO 2-enrichment and FeO t-depletion after saturation in Fe-Ti oxides. However, because of magma mixing in MCU II, they do not follow the same path. Evolved liquids from MCU II are shown to enter the experimentally-determined two liquid stability field, while MCU I liquids do not. Immiscibility in MCU II and its absence in MCU I are supported by the presence of contrasted reactive symplectites in cumulate rocks. Apatite-bearing ferrogabbros in MCU II have crystallized from distinct immiscible Fe-rich and Si-rich silicate melts which have physically segregated in the slow-cooling magma chamber. Two different types of cumulate rocks are thus produced: leucocratic and melanocratic gabbros. This is consistent with the presence of Si-rich and Fe-rich melt inclusions in apatite. In contrast, homogeneous ferrogabbros from MCU I were produced by simple fractional crystallization of a homogeneous liquid. Our data suggest that immiscibility could also explain the large geochemical variability of ferrogabbros in the Upper Zone of the Bushveld Complex (South Africa). © 2012 Elsevier B.V. [less ▲]

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See detailThe dual parametrization for gluon GPDs
Semenov-Tyan-Shanskiy, Kirill ULg

in European Physical Journal A -- Hadrons & Nuclei (2010), 45

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See detailDual parametrization of GPDs versus the double distribution Ansatz
Polyakov, Maxim; Semenov-Tyan-Shanskiy, Kirill ULg

in European Physical Journal A -- Hadrons & Nuclei (2009), 40

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See detailDual Perturb and Combine Algorithm
Geurts, Pierre ULg

in Proceedings of AISTATS 2001, Eighth International Workshop on Artificial Intelligence and Statistics (2001)

In this paper, a dual perturb and combine algorithm is proposed which consists in producing the perturbed predictions at the prediction stage using only one model. To this end, the attribute vector of a ... [more ▼]

In this paper, a dual perturb and combine algorithm is proposed which consists in producing the perturbed predictions at the prediction stage using only one model. To this end, the attribute vector of a test case is perturbed several times by an additive random noise, the model is applied to each of these perturbed vectors and the resulting predictions are aggregated. An analytical version of this algorithm is described in the context of decision tree induction. From experiments on several datasets, it appears that this simple algorithm yields significant improvements on several problems, sometimes comparable to those obtained with bagging. When combined with decision tree bagging, this algorithm also improves accuracy in many problems. [less ▲]

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See detailDual Photon Absorptiometry of Lumbar Spine in West European (Belgian) Postmenopausal Females: Normal Range and Fracture Threshold
Reginster, Jean-Yves ULg; Denis, D.; Deroisy, Rita ULg et al

in Clinical Rheumatology (1990), 9(2), 220-4

Bone mineral content (BMC) and bone mineral density (BMD) of lumbar spine have been measured in 695 healthy postmenopausal and 64 type I osteoporotic Belgian, Caucasian females. Bone loss is strongly ... [more ▼]

Bone mineral content (BMC) and bone mineral density (BMD) of lumbar spine have been measured in 695 healthy postmenopausal and 64 type I osteoporotic Belgian, Caucasian females. Bone loss is strongly correlated to time elapse from menopause (Tm) with a maximum rate of bone loss during the first five years of menopause. BMC (gHA) = 461 + 0.662 ln Tm -0.481 (ln Tm)2 and BMD (gHA/cm2) = 0.91 + 0.00711 ln Tm - 0.00846 (ln Tm)2 (in both cases p less than 0.001 and Tm expressed in months of menopause). After 20 years of menopause, 50 to 60% of normal women have vertebral BMC and BMD values below the 90th percentile of women with vertebral fractures and, thus, might be considered to have asymptomatic osteoporosis. We conclude that prevention of postmenopausal osteoporosis should be initiated as soon as possible after the onset of menopause and that bone density screening should be extended in elderly in order to detect and allow treatment of asymptomatic "densitometric" osteoporosis. [less ▲]

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See detailThe dual purpose Belgian Blue
Colinet, Frédéric ULg

Diverse speeche and writing (2010)

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See detailThe dual purpose Red and White
Colinet, Frédéric ULg

Diverse speeche and writing (2010)

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See detailThe dual role of roads in the visual landscape: a case study in the area around Mechelen (Belgium)
Garré, Sarah ULg; Meeus, Steven; Gulinck, Hubert

in Landscape & Urban Planning (2009), 92(2), 125-135

Roads dominate our daily surroundings and are essential conditions of the access to the visual landscape. This paper focuses on the dual landscape role of secondary and tertiary roads in a semi-rural ... [more ▼]

Roads dominate our daily surroundings and are essential conditions of the access to the visual landscape. This paper focuses on the dual landscape role of secondary and tertiary roads in a semi-rural setting, to be understood as the access to scenery and as their direct influence to the landscape characteristics. A combination of techniques was used including a radiocentric morphological landscape analysis, a perception study on landscape photographs and a cumulative logit model to assess the factors of landscape appreciation in this kind of environment. The results show that roads do not entirely open up the information content of the visual landscape. Furthermore, roads and built fabric seem to have a negative impact on landscape appreciation. This result does not rely on the structures themselves, but on the artificial materials they are constructed of. The methodology applied proves to be useful and is probably applicable in other geographical contexts. It can be a supporting tool to plan and manage road networks for improvement of landscape quality, especially in parts of the countryside strongly affected by urban sprawl. [less ▲]

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See detailThe Dual Role of Thymic Neurohypophysial-Related Self Peptides in T Cell Selection. Physiological and Pharmacological Implications
Geenen, Vincent ULg; Martens, Henri ULg; Robert, Françoise et al

in Annals of the New York Academy of Sciences (1993), 689

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See detailThe dual role of weather forecasts on changes in activity-travel behavior
Cools, Mario ULg; Creemers, Lieve

in Journal of Transport Geography (2013), 28

A deeper understanding of how human activity-travel behavior is affected by various weather conditions is essential for both policy makers and traffic managers. To unravel the ambiguity in findings ... [more ▼]

A deeper understanding of how human activity-travel behavior is affected by various weather conditions is essential for both policy makers and traffic managers. To unravel the ambiguity in findings reported in the literature, the main objective of this paper is to obtain an accurate assessment of how weather forecasts trigger changes in Flemish activity-travel behavior. To this end, data were collected by means of a stated adaptation experiment, which was administered both on the Internet and via traditional paper-and-pencil questionnaires. To address the main research question of this paper, two statistical techniques were adopted. The first technique is the computation of Pearson chi-square independence tests. The second approach is the estimation of a GEE-MNL-model. The results from both techniques underscore the dual role of weather forecasts on changes in activity-travel behavior. On the one hand, the results clearly illustrate the significant effect of forecasted weather; the likelihood of changes in activity-travel behavior significantly depends on the weather forecasted. On the other hand, different methods of acquiring weather information (exposure, media source, or perceived reliability) do not impact the probability of behavioral adaptations. This duality may be partially attributable to the discrepancy that exists between weather forecasts and true traffic and roadway conditions. Therefore, the implementation of a road weather information system that is directly linked to the weather forecasts is recommended. [less ▲]

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See detailThe dual role of weather forecasts on changes in activity-travel behavior
Cools, Mario ULg; Creemers, Lieve; Janssens, Davy et al

Conference (2011)

In previous studies, conflicting results could be found regarding the impact of weather forecasts on travel decisions, e.g. Khattak and De Palma (1997) found no significant effect of acquiring forecasted ... [more ▼]

In previous studies, conflicting results could be found regarding the impact of weather forecasts on travel decisions, e.g. Khattak and De Palma (1997) found no significant effect of acquiring forecasted weather information on the probability of adapting mode and departure time, whereas the results reported by Hagens (2005), Niina (2009) and Kilpelainen and Summala (2007) indicated that weather forecast do play an important role. Therefore this paper investigates the changes in activity-travel behavior in response to weather forecasts. The data for this study is collected by means of a stated adaptation survey, which is both administered on the internet and via a traditional paper and pencil questionnaire. In total, 595 respondents completed the survey. To obtain an optimal correspondence between the true population and the sample weights are assigned to the observation. Results indicate that weather information plays a dual role. On the one hand people do alter their activity-travel behavior in response to weather information, albeit these changes are not as pronounced when compared to actual weather. On the other hand the extent (frequency and media type) to which people are exposed to these weather forecasts appears to play only a marginal role. This dual role weather information plays in this study appears to be supported by the conflicting international literature and therefore revealing the underlying psychological motivations to change one's activity-travel behavior is a key challenge for further research. [less ▲]

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See detailDual stimuli-responsive coating designed through layer-by-layer assembly of PAA-b-PNIPAM block copolymers for the control of protein adsorption
Osypova, Alina; Magnin, Delphine; Sibret, Pierre ULg et al

in Soft Matter (2015), 11(41), 8154-8164

In this paper, we describe the successful construction, characteristics and interaction with proteins of stimuli-responsive thin nanostructured films prepared by layer-by-layer (LbL) sequential assembly ... [more ▼]

In this paper, we describe the successful construction, characteristics and interaction with proteins of stimuli-responsive thin nanostructured films prepared by layer-by-layer (LbL) sequential assembly of PNIPAM-containing polyelectrolytes and PAH. PAA-b-PNIPAM block copolymers were synthesized in order to benefit from (i) the ionizable properties of PAA, to be involved in the LbL assembly, and (ii) the sensitivity of PNIPAM to temperature stimulus. The impact of parameters related to the structure and size of the macromolecules (their molecular weight and the relative degree of polymerization of PAA and PNIPAM), and the interaction with proteins under physico-chemical stimuli, such as pH and temperature, are carefully investigated. The incorporation of PAA-b-PNIPAM into multilayered films is shown to be successful whatever the block copolymer used, resulting in slightly thicker films than the corresponding (PAA/PAH)n film. Importantly, the protein adsorption studies demonstrate that it is possible to alter the adsorption behavior of proteins on (PAA-b-PNIPAM/PAH)n surfaces by varying the temperature and/or the pH of the medium, which seems to be intimately related to two key factors: (i) the ability of PNIPAM units to undergo conformational changes and (ii) the structural changes of the film made of weak polyelectrolytes. The simplicity of construction of these PNIPAM block copolymer-based LbL coatings on a large range of substrates, combined with their highly tunable features, make them ideal candidates to be employed for various biomedical applications requiring the control of protein adsorption. [less ▲]

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See detailA dual strategy to cope with high light in Chlamydomonas reinhardtii
Allorent, G; Tokutsu, R; Roach, T et al

in Plant Cell (2013), 25(2), 545-557

Absorption of light in excess of the capacity for photosynthetic electron transport is damaging to photosynthetic organisms. Several mechanisms exist to avoid photodamage, which are collectively referred ... [more ▼]

Absorption of light in excess of the capacity for photosynthetic electron transport is damaging to photosynthetic organisms. Several mechanisms exist to avoid photodamage, which are collectively referred to as nonphotochemical quenching. This term comprises at least two major processes. State transitions (qT) represent changes in the relative antenna sizes of photosystems II and I. High energy quenching (qE) is the increased thermal dissipation of light energy triggered by lumen acidification. To investigate the respective roles of qE and qT in photoprotection, a mutant (npq4 stt7-9) was generated in Chlamydomonas reinhardtii by crossing the state transition–deficient mutant (stt7-9) with a strain having a largely reduced qE capacity (npq4). The comparative phenotypic analysis of the wild type, single mutants, and double mutants reveals that both state transitions and qE are induced by high light. Moreover, the double mutant exhibits an increased photosensitivity with respect to the single mutants and the wild type. Therefore, we suggest that besides qE, state transitions also play a photoprotective role during high light acclimation of the cells, most likely by decreasing hydrogen peroxide production. These results are discussed in terms of the relative photoprotective benefit related to thermal dissipation of excess light and/or to the physical displacement of antennas from photosystem II. [less ▲]

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See detailDual substrate specificity of Bacillus subtilis PBP4a
Nemmara, Venkatesh V.; Adediran, S. A.; Dave, Kinjal et al

in Biochemistry (2013), 52

Bacterial DD-peptidases are the targets of the β-lactam antibiotics. The sharp increase in bacterial resistance toward these antibiotics in recent years has stimulated the search for non- β-lactam ... [more ▼]

Bacterial DD-peptidases are the targets of the β-lactam antibiotics. The sharp increase in bacterial resistance toward these antibiotics in recent years has stimulated the search for non- β-lactam alternatives. The substrates of DD-peptidases are elements of peptidoglycan from bacterial cell walls. Attempts to base DD-peptidase inhibitor design on peptidoglycan structure, however, have not been particularly successful to date because the specific substrates for most of these enzymes are unknown. It is known, however, that the preferred substrates of low-molecular mass (LMM) class B and C DD-peptidases contain the free N-terminus of the relevant peptidoglycan. Two very similar LMMC enzymes, for example, the Actinomadura R39 DD-peptidase and Bacillus subtilis PBP4a, recognize a D-α-aminopimelyl terminus. The peptidoglycan of B. subtilis in the vegetative stage, however, has the N-terminal D-α-aminopimelyl carboxylic acid amidated. The question is, therefore, whether the DD-peptidases of B. subtilis are separately specific to carboxylate or carboxamide or have dual specificity. This paper describes an investigation of this issue with B. subtilis PBP4a. This enzyme was indeed found to have a dual specificity for peptide substrates, both in the acyl donor and in the acyl acceptor sites. In contrast, the R39 DD-peptidase, from an organism in which the peptidoglycan is not amidated, has a strong preference for a terminal carboxylate. It was also found that acyl acceptors, reacting with acyl−enzyme intermediates, were preferentially D-amino acid amides for PBP4a and the corresponding amino acids for the R39 DD-peptidase. Examination of the relevant crystal structures, aided by molecular modeling, suggested that the expansion of specificity in PBP4a accompanies a change of Arg351 in the R39 enzyme and most LMMC DD-peptidases to histidine in PBP4a and its orthologs in other Bacillus sp. This histidine, in neutral form at pH 7, appeared to be able to favorably interact with both carboxylate and carboxamide termini of substrates, in agreement with the kinetic data. It may still be possible, in specific cases, to combat bacteria with new antibiotics based on particular elements of their peptidoglycan structure. [less ▲]

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See detailDual tachykinin NK1/NK2 antagonist DNK333 inhibits neurokinin A-induced bronchoconstriction in asthma patients
Joos, G. F.; Vincken, W.; Louis, Renaud ULg et al

in European Respiratory Journal (2004), 23(1), 76-81

Inhalation of neurokinin A (NKA) causes bronchoconstriction in patients with asthma. In vitro both tachykinin NK1 and NK2 receptors can mediate airway contraction. In this study the authors examined the ... [more ▼]

Inhalation of neurokinin A (NKA) causes bronchoconstriction in patients with asthma. In vitro both tachykinin NK1 and NK2 receptors can mediate airway contraction. In this study the authors examined the effects of a single dose of the dual tachykinin NK1/NK2 receptor antagonist, DNK333, on NKA-induced bronchoconstriction in asthma. A total of 19 male adults with mild asthma completed a randomised, double-blind, placebo-controlled crossover trial. Increasing concentrations of NKA (3.3 x 10(-9) to 1.0 x 10(-6) mol(.)mL(-1)) were inhaled at 1 and 10 h intervals after a single oral dosing with either DNK333 (100 mg) or a placebo. It was observed that DNK333 did not affect baseline lung function but did protect against NKA-induced bronchoconstriction in those patients. The mean log(10) provocative concentration causing a 20% fall in forced expiratory volume in one second for NKA was -5.6 log(10) mol(.)mL(-1) at 1 h after DNK333 treatment and -6.8 log(10) mol(.)mL(-1) after placebo. This was equivalent to a difference of 4.08 doubling doses, which decreased to a difference of 0.90 doubling doses 10 h after treatment. The results shown in this report indicate that DNK333 blocks neurokinin A-induced bronchoconstriction in patients with asthma. [less ▲]

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