How Do Performance Measures Perform
in Journal of Portfolio Management (2007), 33(4), 64-74
The article presents a discussion on how various performance measures actually perform when used in investment portfolio management. The author discusses the empirical quality of performance measures such ... [more ▼]
The article presents a discussion on how various performance measures actually perform when used in investment portfolio management. The author discusses the empirical quality of performance measures such as information ratio (IR), focusing on directional managed portfolios, the Treynor ratio, and an empirical methodology that allows many of the usual errors associated with ratios to be avoided. The author also discusses multi-index models, style-based mutual funds, and style-adjusted performance. [less ▲]Detailed reference viewed: 31 (7 ULg)
How do preschool teacher's requests influence children's behaviors ?
Crahay, Marcel ;
in Teaching & Teacher Education (1991), 7(3), 221-239Detailed reference viewed: 16 (2 ULg)
How do temperate bryophytes face the challenge of a changing environment? Lessons from the past and predictions for the future
Desamore, Aurélie ; Laenen, Benjamin ; et al
in Global Change Biology (2012), 18(9), 2915-2924
Bryophytes are a group of early land plants, whose specific ecophysiological and biological features, including poikilohydry, sensitivity to moderately high temperature and high dispersal ability, make ... [more ▼]
Bryophytes are a group of early land plants, whose specific ecophysiological and biological features, including poikilohydry, sensitivity to moderately high temperature and high dispersal ability, make them ideal candidates for investigating the impact of climate changes. Employing a combined approach of species distribution modelling (SDM) and molecular phylogeography in the temperate moss Homalothecium sericeum, we explore the significance of the Mediterranean refugia, contrasting the southern and northern refugia hypotheses, determine the extent to which recolonization of previously glaciated areas has been facilitated by the high dispersal ability of the species and make predictions on the extent to which it will be impacted by ongoing climate change. The Mediterranean areas exhibit the highest nucleotidic diversities and host a mixture of ancestral, endemic and more recently derived haplotypes. Extra-Mediterranean areas exhibit low genetic diversities and Euro-Siberian populations display a significant signal of expansion that is identified to be of Euro-Siberian origin, pointing to the northern refugia hypothesis. The SDMs predict a global net increase in range size owing to ongoing climate change, but substantial range reductions in southern areas. Presence of a significant phylogeographical signal at different spatial scales suggests, however, that dispersal limitations might constitute, as opposed to the traditional view of spore-producing plants as efficient dispersers, a constraint for migration. This casts doubts about the ability of the species to face the massive extinctions predicted in the southern areas, threatening their status of reservoir of genetic diversity. © 2012 Blackwell Publishing Ltd. [less ▲]Detailed reference viewed: 16 (2 ULg)
How do users formulate their queries? A morpho-syntactic analysis
Fairon, Nicolas ; Brouwir, Christine ; Durieux, Nancy et al
Conference (2008)Detailed reference viewed: 25 (1 ULg)
How do women entrepreneurs use the virtual network Facebook? The impact of gender
in International Journal of Entrepreneurship & Innovation (2011), 12(4), 257-269
This paper examines the views and attitudes of a sample of 228 female entrepreneurs towards the virtual social network Facebook. It identifies the main trends and uses statistical analysis to evaluate the ... [more ▼]
This paper examines the views and attitudes of a sample of 228 female entrepreneurs towards the virtual social network Facebook. It identifies the main trends and uses statistical analysis to evaluate the impact of their gendered sector of activity and of their self-perception on their view of this network as a response to gender-related difficulties and their use of it in relation to their activities and objectives. The study further investigates how Facebook may encourage and support women’s networks as well as benefit women-owned businesses. It highlights certain implications for public and private initiatives and underlines the potential of this and other virtual social networking sites for women’s entrepreneurship. [less ▲]Detailed reference viewed: 70 (5 ULg)
How does elicitor and antimicrobial fengycin interact with plasma membranes of sensitive cells ?
Nasir, Mehmet Nail ; ; Lins, Laurence et al
Conference (2012, April)
Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ ... [more ▼]
Fengycin is characterized by its strong antifungal and low hemolytic activities. It has also been recently demonstrated that it has plant elicitor properties and is also able to enhance the elicitors’ activity of surfactin. The cell target of its biological activities is supposed to be plasma membrane. In spite of these interesting biological activities, fengycin has not been extensively investigated probably because of the difficulties related to its production. In a first time; we have characterized the interfacial properties of fengycin by tensiometry measurements and demonstrated that this surface activity was pH-dependent. In a second time; we have investigated the interactions of the lipopeptide with membrane lipids using model membranes such as Langmuir monolayers and multilammelar vesicles (MLVs). Our results indicate that the lipopeptide was able to penetrate into different lipid monolayers showing a preference for sterol-containing monolayers. In order to better understand the mechanism of the interactions of fengycin with membranes at the molecular level, MLVs with or without fengycin have been analyzed by spectroscopic techniques. We have shown that conformational changes of the lipopeptide occurred in the presence of lipids and they were more significant in the presence of sterol. Moreover, tyrosine residues of the lipopeptide seem to play an important role in these interactions. In conclusion, we have determined that the surface-active behavior as well as the conformation of fengycin depends on its environment. We have also showed that the lipopeptide does not interact with all class of lipids in the same way and presents a preference for sterols. The presence of key groups within peptide cycle has also been supposed for the biological activities of the lipopeptide. [less ▲]Detailed reference viewed: 106 (16 ULg)
How does engagement in reading predict digital reading proficiency among 15 year-olds?
Lafontaine, Dominique ; Monseur, Christian ; Baye, Ariane
Conference (2012, September)
In PISA 2009, 19 countries took part to an optional assessment of digital reading. In each country, a subsample of 15 year-olds was administered not only the paper and pencil PISA test, but also different ... [more ▼]
In PISA 2009, 19 countries took part to an optional assessment of digital reading. In each country, a subsample of 15 year-olds was administered not only the paper and pencil PISA test, but also different reading tasks online. The aim of our study is to investigate the relationships between engagement in reading, especially online reading practices, and digital reading proficiency of 15 year-olds in the 11 European countries which took part to this option (11 out of 19). [less ▲]Detailed reference viewed: 36 (1 ULg)
How does engagement in reading predict digital reading proficiency among 15 years-olds ?
Baye, Ariane ; Lafontaine, Dominique ; Monseur, Christian
Conference (2012, April 15)Detailed reference viewed: 8 (0 ULg)
How does the age of hoverfly females affect their reproduction?
; Verheggen, François ; Francis, Frédéric et al
in Communications in Agricultural and Applied Biological Sciences (2007), 72(3),Detailed reference viewed: 28 (5 ULg)
How does the age of hoverfly females affect their reproduction?
; Verheggen, François ; Francis, Frédéric et al
Conference (2007)Detailed reference viewed: 8 (2 ULg)
How does the efficacy of Protelos translate into patient benefits ?
in Osteoporosis International (2009, March), 20(Suppl.1), 178Detailed reference viewed: 27 (1 ULg)
How does the organizational context influence the Competitive Intelligence process among Walloon SMEs?
Master's dissertation (2012)
In this increasingly turbulent, global and competitive context, it becomes critical for companies to create and sustain a competitive advantage. Competitive Intelligence (CI), defined as “the process by ... [more ▼]
In this increasingly turbulent, global and competitive context, it becomes critical for companies to create and sustain a competitive advantage. Competitive Intelligence (CI), defined as “the process by which organizations gather information on competitors and the competitive environment [...]” (Wright, Eid & Fleisher, 2009, p.942), can contribute to do so by enabling managers to be aware of and respond to changes in their competitive environment. The CI process includes four steps: (a) planning and focus, (b) data collection, (c) data analysis and (d) communication. First, this paper assesses the level of deployment of CI among Walloon SMEs. Second, it examines the influence of context variables on the CI process. A questionnaire was distributed to 423 Walloon SMEs’ executives, of whom 81 answered. SMEs’ executives were surveyed about their companies’ CI practices as well as their perception of their company’s formal structure, employee involvement and organizational awareness. We found that Walloon SMEs are not very active to conduct CI effectively. Indeed, while Walloon SMEs have recognized that, theoretically, CI is a necessary activity for maintaining a competitive advantage, in practice, most of them do not have yet a well-established CI process in their company. Then, we established the influence of the context in which CI takes place on the success of the CI process. Specifically, we supported that better formal structure, employee involvement and organizational awareness improve the CI process. Finally, we examined the impact of two extra potential antecedents, namely the innovation orientation and the company’s size. We found that innovation-oriented companies tend to exploit CI more than followers. The results lead to several recommendations for SMEs. First, managers should be aware that CI is critical for their company’s survival since the context in which they operate is increasingly competitive. Second, businesses, especially those that are innovation-oriented, should note that an improvement in their formal infrastructure, organizational awareness and employee involvement processes could significantly enhance their CI efficiency. [less ▲]Detailed reference viewed: 80 (9 ULg)
How dynamical clustering triggers Maxwell's demon in microgravity
Opsomer, Eric ; Noirhomme, Martial ; Vandewalle, Nicolas et al
in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2013), 88
In microgravity, the gathering of granular material can be achieved by a dynamical clustering whose existence depends on the geometry of the cell that contains the particles and the energy that is ... [more ▼]
In microgravity, the gathering of granular material can be achieved by a dynamical clustering whose existence depends on the geometry of the cell that contains the particles and the energy that is injected into the system. By compartmentalizing the cell in several subcells of smaller volume, local clustering is triggered and the so formed dense regions act as stable traps. In this paper, molecular dynamics simulations were performed in order to reproduce the phenomenon and to analyze the formation and the stability of such traps. Depending on the total number N of particles present in the whole system, several clustering modes are encountered and a corresponding bifurcation diagram is presented. Moreover, an iterative model based on the measured particle flux F as well as a theoretical model giving the asymptotical steady states are used to validate our results. The obtained results are promising and can provide ways to manipulate grains in microgravity. [less ▲]Detailed reference viewed: 5 (2 ULg)
How ergodic is the Fragmentation of the Pyridine Cation ? A Maximum Entropy Ananlysis
; Locht, Robert ; Lorquet, Andrée et al
in Anton, J.; Cederquist, H.; Larsson, M. (Eds.) et al 23rd International Conference on the Photonic, Electronic and Atomic Collisions: Book of Abstracts. (2003)
The experimental KER and the statistical distributions are compared by the Maximum Entropy Method. An Ergodicity Index F(E) is defined to measure the phase space sampling efficiency. This is applied to ... [more ▼]
The experimental KER and the statistical distributions are compared by the Maximum Entropy Method. An Ergodicity Index F(E) is defined to measure the phase space sampling efficiency. This is applied to the KERD of C4H4+ cation produced by the C5H5N+ -> HCN+C4H4+ fragmentation path. In this particular case the F(E) is found to decrease steadily with increasing internal energy. [less ▲]Detailed reference viewed: 28 (6 ULg)
How ergodic is the fragmentation of the pyridine cation? A maximum entropy analysis
; Locht, Robert ; Lorquet, Andrée et al
in International Journal of Mass Spectrometry (2003), 228(2-3), 389-402
The kinetic energy released to the C4H4+ and HCN fragments produced by the dissociation of the pyridine ion has been determined by a retarding field technique up to an internal energy of 4eV above the ... [more ▼]
The kinetic energy released to the C4H4+ and HCN fragments produced by the dissociation of the pyridine ion has been determined by a retarding field technique up to an internal energy of 4eV above the reaction threshold. This extends our previous study limited to the metastable domain [Int. J. Mass Spectrom. Ion Process. 185/186/187 (1999) 155]. Retarding potential curves resulting from dissociative photoionization using the He(I), Ne(I), and Ar(II) resonance lines have been analyzed by the maximum entropy method. The comparison between the experimentally measured curves and those calculated for the prior (i.e., most statistical) situation reveals the existence of dynamical constraints that prevent phase space from being fully explored. The "ergodicity index" F(E) that measures the efficiency of phase space sampling as a function of the internal energy E of the molecular ion is found to decrease steadily as a function of E and to level off at a value of about 50% when E greater than or equal to 2.5 eV At these high internal energies where phase space exploration no longer decreases, spontaneous intramolecular vibrational energy redistribution (i.e., resulting from the anharmonicity of the molecular vibrations) is thought to contribute to internal energy randomization to a limited extent only. When the lifetime is short, phase space exploration is believed to result instead from the relaxation of the electronic energy via a cascade of non-radiative transitions, which leads to a great diversity of initial conditions, and thus, contributes to statisticity. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲]Detailed reference viewed: 28 (2 ULg)
How eye movements and expertise can explain memory of visual items of central or marginal interest
Blavier, Adelaïde ; Nyssen, Anne-Sophie
in Journal of Vision (2009)
In complex scene, memory for central interest items is better than memory for marginal interest items and this difference remains stable independently of the scene presentation duration (Melcher, 2006 ... [more ▼]
In complex scene, memory for central interest items is better than memory for marginal interest items and this difference remains stable independently of the scene presentation duration (Melcher, 2006). However, without eye movement recording, it is not possible to know whether central interest items are better remembered because they are more fixated or because they are more meaningful. In order to answer this question, we analysed the memory of complex scenes (paintings) according to the eye movements and subjects’ expertise. 15 novice subjects and 15 art historians (experts) were asked to look at 6 paintings that were separately and randomly presented for 10 seconds. After each painting presentation, subjects were asked questions about painting knowledge (author’s name, painting’s name) in order to evaluate their painting knowledge and about pictorial details of 3 categories: details of central or marginal interest and background information. If the expert and novice groups significantly differed concerning the knowledge they had about all paintings, the accuracy of answers about the painting details did not differ between both groups. Moreover, we showed novice’s answers were more accurate when they looked longer at the asked detail and when this detail was watched early on in the presentation while in the expert group, the accuracy of the answer was not influenced by the duration and moment they watched the asked detail. These findings suggest experts have some wrong representations which are not influenced by eye movements contrary to novices whom memory accuracy is influenced by their eye movements. [less ▲]Detailed reference viewed: 81 (7 ULg)
How far and how fast do bryophytes travel at the landscape scale?
Hutsemekers, Virginie ; Dopagne, Claude ; Vanderpoorten, Alain
in Diversity & Distributions (2008), 14(3), 483-492
Dispersal ability is a factor of prime importance to explain biotic distributions. Yet, it is extremely difficult to measure directly. In this study, we take advantage of the natural experimental design ... [more ▼]
Dispersal ability is a factor of prime importance to explain biotic distributions. Yet, it is extremely difficult to measure directly. In this study, we take advantage of the natural experimental design of slag heap colonization in Belgium to document the timing and range of dispersal of bryophytes at the landscape scale. On the basis of a species atlas with a 4 × 4 km grid, the minimum distance separating species found on 52 slag heaps from potential source populations was determined. Minimum dispersal rates were inferred by coupling the information on minimum distance between slag heap and source populations with time since colonization. The number of species per slag heap is significantly correlated with time since colonization and area size. The frequency distribution of the longest dispersal events is highly skewed, with 44% of the species recruited within the nearest 6 km. In the remaining 56% of the species, recruitments from source populations located within a range of at least 6–86 km occurred within a period of less than 50 years. The majority of the species that are not recruited within the nearest vicinity of the slag heaps, including rare species at the regional scale, occur on slag heaps that have been colonized for 25–50 years. Most recently colonized slag heaps are indeed characterized by 'fugitive', weedy species, whereas slag heaps that have been colonized for > 50 years tend to accumulate perennial species with a 'stayer' life strategy. These observations suggest that rare species may display the dispersal ability to travel across the landscape, but are subsequently limited by their ability to establish a viable community because of more competitive neighbours. Rare species therefore tend to accumulate at intermediate colonization stages, which represent a trade-off between an increasing probability of colonization with time and a decreasing probability of establishment due to competition. [less ▲]Detailed reference viewed: 36 (3 ULg)
How fertilizer and soil nitrogen are distributed into winter wheat plant
; Destain, Jean-Pierre ; Bodson, Bernard et al
(2007, September 16)Detailed reference viewed: 18 (0 ULg)
How good are we at extracting personal information from voices?
Dehon, Hedwige ;
Poster (2009, June)Detailed reference viewed: 3 (0 ULg)