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See detailPreventive and Therapeutic Strategies for Bovine Leukemia Virus: Lessons for HTLV
Rodriguez, Sabrina ULg; Florins, Arnaud-Francois ULg; Gillet, Nicolas ULg et al

in Viruses (2011), 3(7), 1210-1248

Bovine leukemia virus (BLV) is a retrovirus closely related to the human T-lymphotropic virus type 1 (HTLV-1). BLV is a major animal health problem worldwide causing important economic losses. A series of ... [more ▼]

Bovine leukemia virus (BLV) is a retrovirus closely related to the human T-lymphotropic virus type 1 (HTLV-1). BLV is a major animal health problem worldwide causing important economic losses. A series of attempts were developed to reduce prevalence, chiefly by eradication of infected cattle, segregation of BLV-free animals and vaccination. Although having been instrumental in regions such as the EU, these strategies were unsuccessful elsewhere mainly due to economic costs, management restrictions and lack of an efficient vaccine. This review, which summarizes the different attempts previously developed to decrease seroprevalence of BLV, may be informative for management of HTLV-1 infection. We also propose a new approach based on competitive infection with virus deletants aiming at reducing proviral loads. [less ▲]

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See detailPreventive Antimigraine Drugs
Silberstein, SD; Latsko, M; Schoenen, Jean ULg

in Fernandez-de-las-Penas, C; Chaitow, L; Schoenen, Jean (Eds.) Multidisciplinary Management of Migraine (2012)

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See detailPreventive assessment and enhancement of power system voltage stability: an integrated approach of thermal and voltage security
Capitanescu, Florin ULg

Doctoral thesis (2003)

This thesis is devoted to the preventive assessment and enhancement of voltage stability and security in electric power systems. However, in the course of deriving all the proposed methods we have paid ... [more ▼]

This thesis is devoted to the preventive assessment and enhancement of voltage stability and security in electric power systems. However, in the course of deriving all the proposed methods we have paid attention to keeping them compatible with the (more traditional) handling of thermal overloads, thereby providing a unified treatment of voltage and thermal security. The approaches presented in this work apply to both deregulated environments and classical, vertically integrated ones. The heart of most methods developed in this thesis is : (i) the derivation of sensitivities indicating the relative efficiency of the various bus injections to restore voltage stability or increase an insufficient voltage security margin, and (ii) the use of these sensitivities in linearized security constraints that can be incorporated to various optimization problems. Using this formulation, we deal with three different problems of interest in preventive security analysis: 1) Congestion management. We propose two optimization-based approaches to manage congestions due to voltage instability and/or thermal overload. The control variables are either power injections (generation rescheduling and load curtailment) or power transactions; 2) Computation of Available Transfer Capabilities (ATCs). We determine the simultaneous ATCs of multiple transactions by means of a single optimization-based computation; 3) evaluation of security margins interval. To face the uncertainty affecting power transfers, we present an optimization-based computation of the minimal and maximal margins under the assumption that individual injections vary within specified bounds. Besides this main theme, the thesis offers additional reflections on the: 1) Filtering of contingencies. We propose a simple and reliable technique to filter out harmless contingencies when computing voltage security margins of a large set of contingencies; 2) Evaluation of reactive reserves with respect to a contingency, an important topic for voltage security reasons as well as within the context of a deregulated market where providing reactive reserves is an ancillary service which should be properly paid. Most of the methods proposed in this thesis were successfully tested on realistic power system models. From a practical viewpoint all the above computations have been coupled to the fast time-domain quasi steady-state simulation used in the ASTRE software developed at the University of Liège. [less ▲]

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See detailPreventive control of voltage security margins: A multicontingency sensitivity-based approach
Capitanescu, Florin ULg; Van Cutsem, Thierry ULg

in IEEE Transactions on Power Systems (2002), 17(2), 358-364

This paper addresses the problem of changing the operating point of a power system in order to keep voltage security margins with respect to contingencies above some minimal value. Margins take on the ... [more ▼]

This paper addresses the problem of changing the operating point of a power system in order to keep voltage security margins with respect to contingencies above some minimal value. Margins take on the form of maximum pre-contingency power transfers either between a generation and a load area or between two generation areas. They are determined by means of a fast time-domain method. We will first discuss the use of a general optimal power flow, in which linear voltage security constraints are added. The simultaneous control of several (possibly conflicting) contingencies is considered. Then, we will focus on the minimal control change objective. Among the possible controls, emphasis is put on generation rescheduling and load curtailment. Examples are presented on an 80-bus test system as well as on a real system. [less ▲]

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See detailPreventive countermeasures for transient stability-constrained power systems
Ruiz-Vega, Daniel; Ernst, Damien ULg; Pavella, Mania ULg

in Proceedings of the VII Symposium of Specialists in Electric Operational and Expansion Planning (SEPOPE 2000) (2000)

A general transient stability control technique is applied to the design of preventive countermeasures consisting of rescheduling generators’ active power. The technique relies on SIME, a hybrid ... [more ▼]

A general transient stability control technique is applied to the design of preventive countermeasures consisting of rescheduling generators’ active power. The technique relies on SIME, a hybrid direct–time-domain method; and, like SIME, it preserves the accuracy of time-domain methods and their ability to handle any power system modeling, stability scenario and mode of instability. Its application to generation rescheduling may provide various patterns, able to comply with various operational specifics and strategies, as, for example, congestion management or available transfer capability calculations. The paper suggest how the technique may be shaped to choose automatically rescheduling patterns. A sample of such patterns are illustrated via simulations performed on an EPRI test system. [less ▲]

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See detailPreventive use of bronchodilators reduces bronchoscopy-induced airflow limitation in cats
Kirschvink, N.; Leemans, J.; Delvaux, F. et al

in ACVIM Meeting - Minneapolis - USA - Juin 2004 (2004, June)

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See detailPreventive vs. emergency control of power systems
Wehenkel, Louis ULg; Pavella, Mania ULg

(2004)

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. The ... [more ▼]

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. The organization of the resulting control schemes is then revisited in order to make it able to cover static and voltage security, in addition to transient stability. Distinct approaches for preventive and emergency operating conditions are advocated. [less ▲]

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See detailPrevious errorless sequence-learning promotes subsequent SRT performance in patients with Alzheimer's Disease
Schmitz, Xavier ULg; Bier, Nathalie; Joubert, Sven et al

Poster (2012, July 17)

Motor-learning capacities are known to be relatively preserved in Alzheimer's disease (AD), which is crucial in the context of the patient’s autonomy (e.g., Rouleau et al., 2002). However, it is important ... [more ▼]

Motor-learning capacities are known to be relatively preserved in Alzheimer's disease (AD), which is crucial in the context of the patient’s autonomy (e.g., Rouleau et al., 2002). However, it is important to determine the most appropriate techniques for such learning. In AD, implicit or procedural rehabilitation techniques would be more effective to train new skills than explicit or declarative learning methods (van Halteren-van Tilborg, 2007). Maxwell et al. (2001) showed that reducing errors during motor learning minimizes the building of declarative knowledge and would allow implicit knowledge accumulation. If errorless learning induces the formation of an implicit knowledge, this technique appears to be adapted to the learning of a perceptual-motor skill in patients with impaired controlled processes. Very few studies have investigated errorless learning in procedural learning situations, even though some data suggest that errorless learning would be efficient for learning instrumental activities of daily living (e.g., Thivierge et al., 2008). In this study we examined the acquisition of a new perceptual-motor skill in 12 patients with AD and 12 healthy older adults. We compared the impact of two preliminary sequence learning conditions (errorless vs. errorful) on a serial reaction time (SRT) performance. In SRT, the subject must react as quickly as possible to the appearance of a target on a screen by pressing the key corresponding to the position of the stimulus. The effectiveness of learning is demonstrated by a reaction time improvement when the target follows a repeating sequence. For patients with AD, results confirm that the advantage provided by prior learning occurs only in the errorless condition whereas both learning modes improve SRT performance in healthy participants. In conclusion, these results confirm that the errorless learning promotes the development of implicit knowledge and appears to be an effective method for procedural learning in Alzheimer's disease. [less ▲]

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See detailPrévision analytique des défauts d'usinage en chariotage
Debongnie, Jean-François ULg

Report (1994)

This report presents an analytical approach leading to a prediction of the form errors arising when turning a bar, in the three classical fixture configurations. This study consists in determing the ... [more ▼]

This report presents an analytical approach leading to a prediction of the form errors arising when turning a bar, in the three classical fixture configurations. This study consists in determing the radial displacement at the tool end, due to the cutting forces. This displacement, will be retreived with the opposite sign, as a diameter error. Traditional analyses only consider the passive component of the cutting force. Here, the effect of the feed force is also considered. [less ▲]

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See detailPrévision de la dégradabilité in situ des matières azotées des fourrages par une méthode enzymatique.
Kamoun, Mohammed; Beckers, Yves ULg; Lecomte, Philippe et al

in 3èmes Rencontres autour de la Recherche sur les Ruminants, Paris, France, 4-5 décembre 1996 (1996, December)

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See detailPrévision de la dégradabilité in situ des matières azotées des fourrages par une méthode enzymatique.
Kamoun, Mohammed; Beckers, Yves ULg; Lecomte, Philippe et al

Conference (1997)

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See detailPrévision de la production nationale d’arachide au Sénégal à partir du modèle agrométéorologique AMS et du NDVI
Kouadio, Amani Louis ULg

Master's dissertation (2007)

Au Sénégal, à l’instar de la plupart des pays subsahariens, l’agriculture est largement tributaire des conditions climatiques. L’agriculture paysanne occupe 60% de la population active et contribue pour ... [more ▼]

Au Sénégal, à l’instar de la plupart des pays subsahariens, l’agriculture est largement tributaire des conditions climatiques. L’agriculture paysanne occupe 60% de la population active et contribue pour 20% au PIB. Elle est dominée par plusieurs filières dont la filière arachide. L’objectif de cette étude est de trouver un modèle de prévision de la production nationale d’arachide à la troisième décade des mois de septembre et d’octobre. Ce modèle est basé sur la prévision du rendement de la culture au niveau départemental à partir des sorties du modèle agrométéorologique AgroMetShell, des données NDVI et de données météorologiques. Cette étude qui constitue une première approche dans la prévision du rendement de l’arachide, montre que la relation trouvée entre le rendement à l’échelle départementale à la troisième décade d’octobre et les variables explicatives fournit une bonne prévision du rendement de l’arachide à l’échelle nationale, avec un R² = 0.55 et une erreur de prédiction faible (RMSE = 28 kg/ha). [less ▲]

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See detailPrévision de la quantité d'herbe ingérée par la vache laitière au pâturage. Comparaison de méthodes d'estimation de la digestibilité et du mode d'échantillonnage des fèces
Biston, Robert; Bartiaux-Thill, Nicole; Théwis, André et al

in Reproduction Nutrition Development (1988), 28

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See detailPrévision de la quantité d'herbe ingérée par la vache laitière au pâturage. Comparaison de méthodes d'estimation de la digestibilité et du mode d'échantillonnage des fécès.
Biston, Roger; Bartiaux-Thill, Nicole; Thewis, André ULg et al

in Reproduction Nutrition Development (1988), 28(Suppl. 1), 61-62

Herbage intake of grazing dairy cows was estimated with several techniques. Grab sampling introduced an upwards bias in the estimate of faecal output comparison with field sampling. Estimates of OM ... [more ▼]

Herbage intake of grazing dairy cows was estimated with several techniques. Grab sampling introduced an upwards bias in the estimate of faecal output comparison with field sampling. Estimates of OM digestibility by NIR and faecal indexes methods were similar except with high level of concentrates. [less ▲]

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See detailPrévision de productions agricoles dans les dix pays de la Communauté Economique Européenne
Dagnelie, P.; Palm, Rodolphe ULg; Istasse, A.

Report (1983)

Detailed reference viewed: 6 (0 ULg)