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See detailEvaluation of Heat Stress Effects on Production Traits and Somatic Cell Score of Holsteins in a Temperate Environment
Hammami, Hedi ULg; Bormann, Jeanne; M'Hamdi, Naceur et al

in Journal of Dairy Science (2013), 96(3), 1844-1855

This study was aimed to evaluate the degree of thermal stress exhibited by Holsteins under a continental temperate climate. Milk, fat, protein, and somatic cell count test-day records collected between ... [more ▼]

This study was aimed to evaluate the degree of thermal stress exhibited by Holsteins under a continental temperate climate. Milk, fat, protein, and somatic cell count test-day records collected between 2000 and 2011 from 23,963 cows in 604 herds were combined with meteorological data from 14 public weather stations in Luxembourg. Daily values of six different thermal indices (TI) weighted in term of temperature, relative humidity, solar radiation, and wind speed were calculated by averaging hourly TI over 24 hours. Heat stress thresholds were firstly identified by a broken-line regression model. Regression models were thereafter applied to quantify milk production losses due to heat stress. The tipping points at which milk and protein yields declined were effectively identified. For fat yield, no valid threshold was identified for any of the studied TI. Daily fat yields tended to decrease steadily with increasing values of TI. Daily somatic cell scores (SCS) pattern was marked by increased values at both lowest and highest TI ranges with a more pronounced reaction to cold stress for apparent temperature indices. Thresholds differed between TI and traits. For production traits, they ranged from 62 (TI1) to 80 (TI3) for temperature-humidity indices (THI) and from 16 (TI5) to 20 (TI6) for apparent temperature indices. Corresponding SCS thresholds were higher and ranged from 66 (TI1) to 82 (TI3) and from 20 (TI5) to 23 (TI6), respectively. The largest milk decline per unit of mild, moderate, and extreme heat stress levels of 0.164, 0.356, and 0.955 kg, respectively, was observed when using the conventional THI (TI1). The highest yearly milk, fat, and protein losses of 54, 5.7, and 4.2 kg respectively were detected by TI2, the THI index that is adjusted for wind speed and solar radiation. The latter index could be considered as the best indicator of heat stress to be used for forecast and herd management in a first step in temperate regions under anticipated climate changes. [less ▲]

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See detailLeptospira spp. prevalence in small mammal populations in Cotonou, Benin
Houemenou, Gualbert ULg; Ahmed, A.; Libois, Roland ULg et al

in ISRN Epidemiology (2013)

The aim of this study was to assess the Leptospira prevalence in small animals in Cotonou, the capital of Benin. Rodents and shrews were captured in urban and periurban settings and determined as species ... [more ▼]

The aim of this study was to assess the Leptospira prevalence in small animals in Cotonou, the capital of Benin. Rodents and shrews were captured in urban and periurban settings and determined as species of the genera Rattus, Mastomys, and Crocidura. Kidney specimens of 90 animals were examined using a real-time PCR assay specific for leptospires that belong to pathogenic species. Leptospiral DNA was amplified from kidney tissues ranging from 13.3% (8/60) in Rattus rattus to 100.0% (1/1) in Crocidura spp. with an average of 18.9% (17/90) of the animals caught at 15 locations. Clade-specific Taqman PCR on 10 samples placed six of these within clade 1 comprising the species L. kirschneri, L. interrogans, L. meyeri, and L. noguchii and four within clade 2 consisting of species L. weilii, L. alexanderi, L. borgpetersenii, and L. santarosai. Phylogenetic analysis of partial sequences of the amplicons of seven samples of these 10 samples revealed that four of the clade 1 samples could equally be assigned to L. interrogans and L. kirschneri and three samples fromclade 2 belonged to L. borgpetersenii. Results presented in the paper indicate that small mammals present a major public health risk for acquiring leptospirosis in Cotonou, Benin and will contribute to a raised awareness amongst health care workers and decision makers and hence promote appropriate clinical management of cases. [less ▲]

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See detailHigh-precision CoRoT space photometry and fundamental parameter determination of the B2.5V star HD 48977
Thoul, Anne ULg; Degroote, Pieter; Catala, Claude et al

in Astronomy and Astrophysics (2013), 551

We present the CoRoT light curve of the bright B2.5V star HD 48977 observed during a short run of the mission in 2008, as well as a high-resolution spectrum gathered with the HERMES spectrograph at the ... [more ▼]

We present the CoRoT light curve of the bright B2.5V star HD 48977 observed during a short run of the mission in 2008, as well as a high-resolution spectrum gathered with the HERMES spectrograph at the Mercator telescope. We use several time series analysis tools to explore the nature of the variations present in the light curve. We perform a detailed analysis of the spectrum of the star to determine its fundamental parameters and its element abundances. We find a large number of high-order g-modes, and one rotationally induced frequency. We find stable low-amplitude frequencies in the p-mode regime as well. We conclude that HD 48977 is a new Slowly Pulsating B star with fundamental parameters found to be Teff = 20000 $\pm$ 1000 K and log(g)=4.2 $/pm$ 0.1. The element abundances are similar to those found for other B stars in the solar neighbourhood. HD 48977 was observed during a short run of the CoRoT satellite implying that the frequency precision is insufficient to perform asteroseismic modelling of the star. Nevertheless, we show that a longer time series of this star would be promising for such modelling. Our present study contributes to a detailed mapping of the instability strips of B stars in view of the dominance of g-mode pulsations in the star, several of which occur in the gravito-inertial regime. [less ▲]

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See detailEvaluation of viability and growth of Acetobacter senegalensis under different stress conditions
Shafiei, Rasoul ULg; Thonart, Philippe ULg; Delvigne, Frank ULg et al

in International Journal of Food Microbiology (2013)

Acetic acid bacteria (AAB) are used in production of vinegars. During acetic acid fermentation, AAB encounter various aggressive conditions which may lead to a variety of cellular disorders. Previous ... [more ▼]

Acetic acid bacteria (AAB) are used in production of vinegars. During acetic acid fermentation, AAB encounter various aggressive conditions which may lead to a variety of cellular disorders. Previous researches mainly studied the influences of different carbon sources on tolerance of AAB to ethanol and acetic acid. In this study, different techniques were used comparatively to investigate the effects of preadaptation on the ability of A. senegalensis to tolerate ethanol and acetic acid. In general, the carbon sources used for preadaptation of A. senegalensis exhibited significant effects on the tolerance of cells to stressors. Flow-cytometric assessments of preadapted cells in ethanol showed that 87.3% of the cells perform respiration after exposure to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid. However, 58.4% of these preadapted cells could keep their envelope integrity under the stress condition. They could also grow rapidly (μmax = 0.39/h) in the stress medium (E5A3) with a high yield (>80%). A. senegalensis grown in glucose exhibited a low tolerance to acetic acid. Analysis of their respiration capacity, membrane integrity and culturability revealed that almost all the population were dead after exposure to 5% (v/v) ethanol and 3% (w/v) acetic acid. In contrast, exposure of A. senegalensis preadapted in a mixture of glucose and acetic acid to a stress medium containing 5% (v/v) ethanol and 3% (w/v) acetic acid, exhibited an intact respiration system and cellular membrane integrity in 80.3% and 50.01% of cells, respectively. Moreover, just 24% of these cells could keep their culturability under that stress condition. [less ▲]

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See detailThiamine and thiazolium binding proteome includes DJ-1, amyloid beta and several membrane proteins
Bunik; Parkhomenko, Y; Kaehne, T et al

Poster (2013, March)

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See detailPatterns of Management Control for Sustainability
Crutzen, Nathalie ULg; Zvezdov, Dimitar; Schaltegger, Stefan

Conference (2013, March)

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See detailInfluence of particle shape on size distribution measurements by 3D and 2D image analyses and laser diffraction
Califice, Arnaud ULg; Michel, Frédéric ULg; Dislaire, Godefroid ULg et al

in Powder Technology (2013), 237

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser ... [more ▼]

This paper highlights the fact that particle size distribution (PSD) is not unique for the same product, and is dependent on the chosen measurement technique, especially for asymmetric shapes. Laser diffraction and 2D image analysis are commonly used PSD measurement techniques. However, the resultsmay not be representative of the true physical dimensions of the particles. The influence of particle shape on PSD results obtained from 2D/3D image analysis and laser diffraction was investigated. Two metallic powders presenting extreme shape properties (round and elongated particles) were analyzed, as well as a blend of the two pure products. 2D image analysis and laser diffraction results were compared to 3D image analysis (measuring the true particle size). This paper compares the PSD results obtained from the three methods. Some commonly used size parameters in image analysis software did not give meaningful results in regard of the true physical dimensions of the particles. The existence of the two populations (products with extremely different shape and size characteristics) could not be identified with such size parameters, and laser diffraction also performed poorly. The PSD obtained from more precise size parameters (image analysis) better corresponded to the true dimensions of the particles. This study highlights the strengths and weaknesses of particle size analysis techniques when studying products presenting diverse particle shapes, and points out that caution is required in the choice of the size parameters, and in the interpretation of PSD results. [less ▲]

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See detailLes représentations d’attachement chez les enfants de 5 à 8 ans placés en institution
Degraux, Christine ULg; Deschênes, Marie; Cyr, Chantal et al

Poster (2013, March)

A ce jour aucune étude n’a investigué la qualité d’attachement d’enfants hébergés en institution suite à de la maltraitance ou des négligences sévères. Or les recherches menées auprès de populations ... [more ▼]

A ce jour aucune étude n’a investigué la qualité d’attachement d’enfants hébergés en institution suite à de la maltraitance ou des négligences sévères. Or les recherches menées auprès de populations maltraitées indiquent de graves conséquences sur leur patron d’attachement ((Cyr et al., 2010) et de plus en plus de recherches soulignent les effets d’un attachement insécurisé sur le développement, surtout s’il est de type désorganisé (Lyons-Ruth & Jacobvitz, 2008). C’est pourtant ce type d’attachement qui est observé auprès d’environ la moitié des adolescents hébergés ou des adultes ayant été hébergés (Nowacki & Schoelmerich, 2010; Wallis & Steele, 2001; Webster et al., 2009). Cette étude a pour objectif d’évaluer la prévalence des modes d’attachement dans un échantillon d’enfants hébergés âgés entre 5 et 8 ans (N=73). L’évaluation de l’attachement a porté non pas sur les comportements d’attachement mais sur les modèles relationnels que les enfants ont intériorisés suite aux expériences vécues auprès de leur(s) figure(s) d’attachement. La procédure des histoires à compléter a été utilisée, filmée et codée en Q-sort via les cartes pour le complément d’histoires (C.C.H.) développé par Miljkovitch et collaborateurs (2003). Les résultats indiquent que 22% des enfants présentent un attachement de type sécure, 37% de désorganisé, 31% d’évitant et 10% d’ambivalent. Ceux-ci soulignent qu’à cet âge aussi, la désorganisation est observée dans de nombreux cas et nous constatons également qu’un nombre élevé d’enfants présentent des stratégies d’évitement qui risquent de leur causer de nombreuses difficultés relationnelles. Etant donné l’importance d’une prise en charge précoce des troubles d’attachement, il est primordial de s’interroger sur les interventions à proposer dans un cadre institutionnel face aux besoins spécifiques de ces enfants. [less ▲]

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See detailLa philosophie dès le primaire ! Quelques difficultés à surmonter
Gauthier, Jean-Marie ULg

in La philo mode d'emploi (2013), 236

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See detailD31-1254: Influence de l'âge et du poids d'abattage sur la qualité organoleptique du poulet de chair à croissance lente en Région wallonne (Rapport final).
De Maeseneire, Coraline ULg; Beckers, Yves ULg; Thewis, André ULg

Report (2013)

Ces dernières années, la progression de la production avicole en Wallonie est, en grande partie, liée au développement de filières dites de qualité différenciée. En 2009, ce sont près de 2.000.000 de ... [more ▼]

Ces dernières années, la progression de la production avicole en Wallonie est, en grande partie, liée au développement de filières dites de qualité différenciée. En 2009, ce sont près de 2.000.000 de poulets qui ont été associés à ce type de production. Cependant, contrairement au poulet standard pour lesquels les pratiques sont très standardisées, les pratiques d’élevage en qualité différenciée peuvent varier, notamment la génétique, l’âge et le poids à l’abattage, le sexe de l’animal, l’accès à un parcours… Ces variations peuvent influencer l’homogénéité de la qualité organoleptique de la viande de poulet au sein d’une même filière ainsi que la perception (et la confiance) des consommateurs vis-à-vis de la viande des poulets qui en sont issus. L’objectif de ce projet est d’étudier et d’objectiver de manière scientifique la qualité organoleptique de la viande de poulet de chair au sein de trois filières avicoles de qualité différenciée afin de fournir aux détenteurs de ces filières des informations quant aux facteurs susceptibles de modifier la qualité organoleptique de leurs produits ainsi que la perception de ceux-ci par les consommateurs. [less ▲]

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See detailRole of KOPAKAMA in promoting socio-economic development of coffee farmers
Gisaro Ca-Madeberi, Ya-Bititi ULg; Lebailly, Philippe ULg; Burny, Philippe ULg et al

in International NGO Journal (2013), 8(3), 61-67

Coffee is the main source of income for a large number of households and provides major foreign currencies for the national economy. Although it covers only 6.3% of cultivated areas, coffee is produced by ... [more ▼]

Coffee is the main source of income for a large number of households and provides major foreign currencies for the national economy. Although it covers only 6.3% of cultivated areas, coffee is produced by 500,000 households in Rwanda. Since its introduction in the country in 1904, coffee has always been operated by individual producers. However, after the liberalization of the coffee sector in 1998, the quantity and quality produced are steadily decreasing which affects the price and the income of coffee growers. To search for a solution, the Rwandan government has striven to consolidate coffee growing cooperatives in different parts of the country by building coffee washing stations (CWS). These stations were mainly meant to help coffee growing cooperatives produce high quality coffee which is competitive on the international markets. The goal is to produce a fully washed coffee, exportable and better valued on the international market, which can provide better income for peasant producers. Coffee washing stations are then seen as tools to produce quality coffee and are mainly run by cooperatives, which are structural elements in the rural world. Through these facilities and structures put in place, jobs are created for coffee producers, loans are granted, farmers are motivated due to the increase of income, the market is guaranteed and the prices become attractive for the members. Thus, the socio-economic welfare of coffee growers is improved, which reduces poverty among coffee growers’ households. This study focuses on the analysis of the role resulting from the structuring action of the peasants through CWS and coffee cooperative KOPAKAMA Rutsiro District, Western Province of Rwanda on the socio-economic development and technical assistance of members and the surrounding world. [less ▲]

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See detailLong term stability of TiO2 templated multilayer films used as high efficiency photoelectrode in liquid DSSCs
Dewalque, Jennifer ULg; Nguyen, Ngoc Duy ULg; Henrist, Catherine ULg et al

Poster (2013, March)

To our knowledge, the stability results reported in the literature only concern cells made from classical doctor-bladed or screen-printed nanoparticles films. This study focuses on the comparison of the ... [more ▼]

To our knowledge, the stability results reported in the literature only concern cells made from classical doctor-bladed or screen-printed nanoparticles films. This study focuses on the comparison of the long-term stability of these cells with DSSCs working with templated mesoporous films. Indeed, the increased surface area of templated films could lead to a faster degradation of the resulting cells. In accordance with IEC:1646:1996 standard tests, light soaking test at 45°C has been applied to determine the cells stability under prolonged illumination. Moreover, thermal stress in the dark has been applied. Unfortunately, due to the sealing material heat resistance, thermal stress test was only performed at 45°C. [less ▲]

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See detailBehaviour of bolted flange joints in tubular structures under monotonic, repeated and fatigue loadings I: Experimental tests
Hoang, Van Long ULg; Jaspart, Jean-Pierre ULg; Demonceau, Jean-François ULg

in Journal of Constructional Steel Research (2013), 85

This paper presents a test program on bolted flange plate connections used in circular tubular structures. In the tested joints, the connected tubular elements are made of high strength steel (TS590 ... [more ▼]

This paper presents a test program on bolted flange plate connections used in circular tubular structures. In the tested joints, the connected tubular elements are made of high strength steel (TS590) whilst normal steel grade (S355) is used for the flanges. The tests were performed under monotonic loadings to obtain the mechanical properties of the connections and under cyclic loadings to characterise the behaviour of these connections for low cycle and high cycle fatigue. The test results are first presented herein, including a critical analysis of the latter; then, designmethods available in literature are applied for the tested configurations with the objective to investigate the accuracy of these methods through comparisons with the experimental results. [less ▲]

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See detailNumerical simulation of a pyramid steel sheet formed by single point incremental forming using solid-shell finite elements
Duchene, Laurent ULg; Guzmán Inostroza, Carlos Felipe ULg; Behera, Amar Kumar et al

in Key Engineering Materials [=KEM] (2013)

Single Point Incremental Forming (SPIF) is an interesting manufacturing process due to its dieless nature and its increased formability compared to conventional forming processes. Nevertheless, the ... [more ▼]

Single Point Incremental Forming (SPIF) is an interesting manufacturing process due to its dieless nature and its increased formability compared to conventional forming processes. Nevertheless, the process suffers from large geometric deviations when compared to the original CAD profile. One particular example arises when analyzing a truncated two-slope pyramid. In this paper, a finite element simulation of this geometry is carried out using a newly implemented solid-shell element, which is based on the Enhanced Assumed Strain (EAS) and the Assumed Natural Strain (ANS) techniques. The model predicts the shape of the pyramid very well, correctly representing the springback and the through thickness shear (TTS). Besides, the effects of the finite element mesh refinement, the EAS and ANS techniques on the numerical prediction are presented. It is shown that the EAS modes included in the model have a significant influence on the accuracy of the results. [less ▲]

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See detailEgg Production Performance of the Local Kabyle Hen and its Crossbreeds with ISA-Brown Strain in Semi-Intensive Conditions
Moula, Nassim ULg; Mamadou Tandiang, Diaw; Salhi, Abdellah et al

in International Journal of Poultry Sciences (2013), 12(3), 148-152

A cross between the ISA-Brown industrial strain and an Algerian local (Kabyle) breed was compared with the Algerian local (Kabyle) hen. The comparison during the egg production period was done in ... [more ▼]

A cross between the ISA-Brown industrial strain and an Algerian local (Kabyle) breed was compared with the Algerian local (Kabyle) hen. The comparison during the egg production period was done in individual cages, in a ventilated henhouse without any particular isolation. The same commercial diet has been provided over three time periods (35 to 36 weeks, 50 to 51 weeks and 65 to 66 weeks of age). Egg number and body weight at first egg was significantly lower in the Kabyle local breed. Mortality was almost equal during the breeding period and the egg production periods for the two genotypes. The Kabyle hen eggs, in spite of a weight which was lower (43.70 to 53.37 g according to the age), gave yolk to albumen ratio similar to the ISAKAB cross (0.52 to 0.58 according to age). Finally, the ISAKAB cross was better in terms of egg production and egg quality than the local hen, in test conditions. [less ▲]

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See detailCas pratique de droit constitutionnel - Dossier de documentation n° 2
Bouhon, Frédéric ULg

Learning material (2013)

Le recueil rassemble les documents utiles pour deux séances d'études de cas pratiques - partim droit constitutionnel.

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See detailDroit des biens
Lecocq, Pascale ULg

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2013)

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