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See detailNew data on the recent history of the littoral forests of southern Cameroon: an insight into the role of historical human disturbances on the current forest composition
Biwolé, Achille ULg; Morin-Rivat, Julie ULg; Fayolle, Adeline ULg et al

in Plant Ecology and Evolution (in press)

Background and aims – Prior to European colonisation of Central Africa, human populations were dispersed through the forests, where they practiced slash-and-burn cultivation. From the 19th century they ... [more ▼]

Background and aims – Prior to European colonisation of Central Africa, human populations were dispersed through the forests, where they practiced slash-and-burn cultivation. From the 19th century they were progressively concentrated in villages along roads, leaving large areas of forest derelict. In south-western Cameroon, and elsewhere in Central Africa, forest canopy is dominated by long-lived lightdemanding tree species, suggesting a possible role of human disturbance. The aim of this study was to bring new insights into the possible effect of historical human disturbances in terms of timing and spatial extent on the current forest composition. Location – Wet evergreen littoral forest in south-western Cameroon. Methods and key results – A combined vegetation sampling and archaeobotanical survey were conducted. Potsherds, oil-palm endocarps, and charcoal were found throughout the study area, suggesting generalised human occupation and anthropogenic fire. Human occupancy occurred in two periods: between 2200 and 1500 BP, and, more recently, beginning three centuries ago. High frequency of fire and the presence of Elaeis guineensis both dated recently (between 260 and 145 BP) suggest slash-and-burn shifting cultivation practices. These human-induced disturbances may coincide with the age of the current emergent lightdemanding species, the age of which can be estimated around 200 years, or with the phases of drying climate recorded in the Central African forest in the early 18th century. Conclusions – These results support the idea that historical human disturbances are one of the major factors that shaped the current forest composition in Central Africa. [less ▲]

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See detailCharacterizing the morphology of suburban settlements: a method based on a semi-automatic classification of building clusters
de Smet, Fabian; Teller, Jacques ULg

in Landscape Research (in press)

Urban sprawl is transforming our landscapes and rural areas at a spectacular pace. Measuring the strength of the phenomenon and proposing dynamic ways to delineate suburban areas have been the object of ... [more ▼]

Urban sprawl is transforming our landscapes and rural areas at a spectacular pace. Measuring the strength of the phenomenon and proposing dynamic ways to delineate suburban areas have been the object of much debate amongst scientists. The present article takes the view that, beyond measuring and delineating suburban areas, more efforts should be directed to qualifying the morphology of built settlements within these areas. Therefore it proposes a method based on a semi-automatic classification system of building clusters, designed to describe and interpret the phenomenon from a morphological perspective. This method is based on a combination of field surveys with numerical analyses of digital land cadastre maps. The application of this classification system to the suburban area around Liege reveals that, far from developing in a complete indifference of local conditions, contemporary suburban settlements are influenced by landscape structures inherited from the past. [less ▲]

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See detailB fields in OB stars (BOB): on the detection of weak magnetic fields in the two early B-type stars beta CMa and epsilon CMa
Fossati, L.; Castro, N.; Morel, Thierry ULg et al

in ArXiv e-prints (in press), 1411

Within the context of the "B fields in OB stars (BOB)" collaboration, we used the HARPSpol spectropolarimeter to observe the early B-type stars beta CMa (HD44743; B1 II/III) and epsilon CMa (HD52089; B1.5 ... [more ▼]

Within the context of the "B fields in OB stars (BOB)" collaboration, we used the HARPSpol spectropolarimeter to observe the early B-type stars beta CMa (HD44743; B1 II/III) and epsilon CMa (HD52089; B1.5 II). For both stars, we consistently detected the signature of a weak (<30 G in absolute value) longitudinal magnetic field. We determined the physical parameters of both stars and characterise their X-ray spectrum. For beta CMa, our mode identification analysis led to determining a rotation period of 13.6+/-1.2 days and of an inclination angle of the rotation axis of 57.6+/-1.7 degrees, with respect to the line of sight. On the basis of these measurements and assuming a dipolar field geometry, we derived a best fitting obliquity of ~22 degrees and a dipolar magnetic field strength (Bd) of ~100 G (60<Bd<230 G within 1 sigma), below what is typically found for other magnetic massive stars. For epsilon CMa we could only determine a lower limit on the dipolar magnetic field strength of 13 G. For this star, we determine that the rotation period ranges between 1.3 and 24 days. Both stars are expected to have a dynamical magnetosphere. We also conclude that both stars are most likely core hydrogen burning and that they have spent more than 2/3 of their main sequence lifetime. A histogram of the distribution of the dipolar magnetic field strength for the magnetic massive stars known to date does not show the magnetic field "desert" observed instead for intermediate-mass stars. The biases involved in the detection of (weak) magnetic fields in massive stars with the currently available instrumentation and techniques imply that weak fields might be more common than currently observed. Our results show that, if present, even relatively weak magnetic fields are detectable in massive stars and that more observational effort is probably still needed to properly access the magnetic field incidence. [less ▲]

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See detailCombining seismology and spectropolarimetry of hot stars
Neiner, Coralie; Briquet, Maryline ULg; Mathis, Stéphane et al

in IAU Symosium 307 (in press)

Asteroseismology and spectropolarimetry have allowed us to progress significantly in our understanding of the physics of hot stars over the last decade. It is now possible to combine these two techniques ... [more ▼]

Asteroseismology and spectropolarimetry have allowed us to progress significantly in our understanding of the physics of hot stars over the last decade. It is now possible to combine these two techniques to learn even more information about hot stars and constrain their models. While only a few magnetic pulsating hot stars are known as of today and have been studied with both seismology and spectropolarimetry, new opportunities - in particular Kepler2 and BRITE - are emerging and will allow us to rapidly obtain new combined results. [less ▲]

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See detailThe B Fields in OB Stars (BOB) Survey
Morel, Thierry ULg; Castro, N.; Fossati, L. et al

in IAU Symposium (in press)

The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ... [more ▼]

The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects. [less ▲]

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See detailNatural killer and dendritic cells collaborate in the immune response induced by the vaccine against uterine cervical cancer.
Langers, Inge ULg; Renoux, Virginie; Reschner, Anca et al

in European journal of immunology (in press)

Virus-like particles (VLPs) of human papillomavirus (HPV) are used as a vaccine against HPV-induced cancer, and recently we have shown that these VLPs are able to activate natural killer (NK) cells. Since ... [more ▼]

Virus-like particles (VLPs) of human papillomavirus (HPV) are used as a vaccine against HPV-induced cancer, and recently we have shown that these VLPs are able to activate natural killer (NK) cells. Since NK cells collaborate with dendritic cells (DCs) to induce an immune response against viral infections and tumors, we studied the impact of this crosstalk in the context of HPV vaccination. NK cells in the presence of HPV-VLPs enhanced DC maturation as shown by an upregulation of CD86 and HLA-DR and an increased production of IL-12p70, but not of the immunosuppressive cytokine IL-10. This activation was bi-directional. Indeed, in the presence of HPV-VLPs, DCs further activated NK cells by inducing the upregulation of cell surface activation markers (CD69 and HLA-DR). The function of NK cells was also improved as shown by an increase in IFN-gamma secretion and cytotoxic activity against an HPV+ cell line. This crosstalk between NK cells and DCs needed CD40 interaction and IL-12p70 secretion, whereas NKG2D was not implicated. Our results provide insight into how VLPs interact with innate immune cells and how NK cells and DCs play a role in the immune response induced by this vaccine agent. This article is protected by copyright. All rights reserved. [less ▲]

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See detailThe Chronocultural Sequence of Belgian Complexes in the European Aurignacian Context
Flas, Damien ULg

in P@lethnology (in press), 6

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See detailCost monitoring in clam farms in Coastal Nam Dinh Province of Vietnam
Bui Thi, Nga; Tran Huu, Cuong; Lebailly, Philippe ULg

in Scholars Journal of Agriculture and Veterinary Sciences (in press), Nov. 2014-Jan 2015, 2(1),

Clam farming is a strength in the agricultural development of the coastal communes in Nam Dinh province, which has developed rapidly in recent years. It has many advantages of no investment on food, low ... [more ▼]

Clam farming is a strength in the agricultural development of the coastal communes in Nam Dinh province, which has developed rapidly in recent years. It has many advantages of no investment on food, low capital in technique management, simple care, short cultured time. It could bring high profits for the farmers, create employment for labor in rural area and contribute significantly to local economy. In addition, the model of clam farming can be easily replicated so clam farming attracts a lot of attention from the coastal fishermen, policy makers and participation of scientists. However, the development of clam farming in this province is still spontaneous, without obvious planning and sustainable development strategies. In addition, market becomes more competitive. Farmers manage their farms base on experiences and depend too much on natural conditions, thus they are facing many risks. This lead to the situation of inefficiency, and affects negatively to the clam farming and environment. This research aims to study about cost monitoring in clam farms and analyze the factors affecting the cost monitoring in clam farms in Nam Dinh province. From which, suggestions to develop effectively clam farming and contribute to raise incomes for farmers were given in the next years in Nam Dinh province. [less ▲]

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See detailValidated ready-to-use GC-MS/MS method for dioxin analysis in food and feed following the new EU Regulations
L'Homme, Benjamin ULg; Sandy, Chris; Scholl, Georges ULg et al

in Organohalogen Compounds (in press)

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See detailDesigning large-scale CO2 capture units with assessment of solvent degradation
Léonard, Grégoire ULg; Crosset, Cyril; Dumont, Marie-Noëlle ULg et al

in Energy Procedia (in press)

Solvent degradation is one of the main operational drawbacks of post-combustion CO2 capture with amine solvents. Although the different degradation mechanisms have been largely studied in recent years, it ... [more ▼]

Solvent degradation is one of the main operational drawbacks of post-combustion CO2 capture with amine solvents. Although the different degradation mechanisms have been largely studied in recent years, it is still impossible to predict the solvent losses and the emissions of degradation products that may occur in a CO2 capture plant depending on its size and on its operating conditions. In the present work, we experimentally study the degradation of MEA monoethanolamine) under accelerated conditions implying high temperature, continuous gas feed and vigorous agitation. A special focus is set on the oxidative degradation of MEA, which is studied in the absence of CO2. Based on the experimental results, we propose a kinetic model to describe both MEA oxidative and thermal degradation pathways. The degradation kinetics is then included into a global model of the CO2 capture process, enabling solvent losses and emissions of degradation products to be predicted as a function of the process operating conditions. The predicted MEA loss is in the same order of magnitude as reported in degradation measurements from pilot plants, although lower by a factor 3. This kind of model assessing solvent degradation could and should be used for the design of large-scale CO2 capture plants in order to simultaneously consider the energy consumption of the process and its environmental impact related to the emissions of degradation products and amine solvent. Further developments shall consider the effect of SOx, NOx and dissolved metals on MEA degradation. [less ▲]

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See detailRelevance of accelerated conditions for the study of monoethanolamine degradation in post-combustion CO2 capture.
Léonard, Grégoire ULg; Toye, Dominique ULg; Heyen, Georges ULg

in Canadian Journal of Chemical Engineering (in press)

Solvent degradation represents one of the main operational drawbacks of the post-combustion CO2 capture process. Degradation not only induces additional costs for solvent make-up, it also impacts the ... [more ▼]

Solvent degradation represents one of the main operational drawbacks of the post-combustion CO2 capture process. Degradation not only induces additional costs for solvent make-up, it also impacts the process efficiency and its environmental penalty due to the emission of various degradation products. There is still a gap of knowledge about the influence of process operating conditions on degradation, making it currently impossible to predict the solvent degradation rate in CO2 capture plants. Morever, the reaction mechanisms corresponding to solvent degradation are very slow, significantly complicating its study in industrial units. In the present work, appropriate experimental equipment and analytical methods are developed for accelerating the degradation of monoethanolamine solvents (MEA). The relevance of accelerated conditions is established by comparing artificially degraded solvent samples with degraded solvent samples from industrial CO2 capture pilot plants. Two approaches are evaluated implying either discontinuous or continuous gas feed, this latest being the most representative of industrial degradation. The respective influences of the gas feed composition and the gas-liquid transfer are evidenced and quantified. Finally, the present study leads to a better understanding of solvent degradation in the CO2 capture process with MEA. More generally, it also evidences that accelerated conditions at laboratory-scale may provide relevant information for the study of slow phenomena taking place in large-scale industrial processes. Further works include the development of a kinetic model for MEA solvent degradation and the extension of this methodology to other promising solvents in order to facilitate the operation and large-scale deployment of CO2 capture. [less ▲]

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See detailA classification of barycentrically associative polynomial functions
Marichal, Jean-Luc; Mathonet, Pierre ULg; Tomaschek, Jörg

in Aequationes Mathematicae (in press)

We describe the class of polynomial functions which are barycentrically associative over an infinite commutative integral domain.

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See detailHow does governmental versus private venture capital backing affect a firm's efficiency? Evidence from Belgium
Alperovych; Hübner, Georges ULg; Lobet, Fabrice

in Journal of Business Venturing (in press)

We investigate the implications of venture capital (VC) investor type (government or private) on the operating efficiency of a sample of 515 Belgian portfolio firms up to 3 years after the investment. We ... [more ▼]

We investigate the implications of venture capital (VC) investor type (government or private) on the operating efficiency of a sample of 515 Belgian portfolio firms up to 3 years after the investment. We find that the government VC-backed firms display significant reductions in productivity. No significant differences in efficiency are found in firms backed by private VC compared with their non-VC-backed peers. Finally, significant reductions in efficiency exist in targets of government VC compared to their non-VC-backed peers. [less ▲]

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See detailEnzymatic hydrolysis of softwood and hardwood regenerated celluloses
Jacquet, Nicolas ULg; Maniet, Guillaume ULg; Richel, Aurore ULg et al

in Current Chemical Biology (in press)

Regenerated celluloses from Kraft wood pulps (from hardwoods and softwoods) were hydrolysed by mean of cellulase of Trichoderma reesei. Our results highlighted that a 75% hydrolysis yield was reached for ... [more ▼]

Regenerated celluloses from Kraft wood pulps (from hardwoods and softwoods) were hydrolysed by mean of cellulase of Trichoderma reesei. Our results highlighted that a 75% hydrolysis yield was reached for hardwood regenerated cellulose (HRC) and 90% for softwood regenerated cellulose (SRC). Crystallinity indices from X-Ray diffraction patterns were used to measure hydrolysis rate of crystalline and amorphous regions. Addition of β-glucosidase to the enzymatic complex of Trichoderma reesei was confirmed to enhance yields of hydrolysis. [less ▲]

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See detail« À table ! ». Indexation et organisation des livres de cuisine aux 17e et 18e siècles
Colson, Maryse ULg

in Mathieu, Georges (Ed.) Les Tables des matières (in press)

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See detailL’Union européenne et l’interrégionalisme : trajectoire, situation actuelle et perspective
Santander, Sébastian ULg

in Chabal, Pierre (Ed.) Concurrences Interrégionales Europe-Asie au 21ème siècle (in press)

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See detailÉtude anatomoradiologique d’un crâne déformé d’Ancón (Pérou)
Ricciardetto, Antonio ULg; Boman, Françoise; Duchat, Florent et al

in Charlier, Philippe (Ed.) Actes du Ve Colloque international de Pathographie (in press)

Matériels et méthodes : l’étude porte sur un crâne déformé provenant d’Ancón au Pérou, inventorié au Muséum National d’Histoire Naturelle (MNHN) de Paris en 1889. L’étude est géographique, historique ... [more ▼]

Matériels et méthodes : l’étude porte sur un crâne déformé provenant d’Ancón au Pérou, inventorié au Muséum National d’Histoire Naturelle (MNHN) de Paris en 1889. L’étude est géographique, historique, macroscopique et tomodensitométrique. Résultats : situé sur la côte à 40 km au nord de Lima, la capitale du Pérou, le site d’Ancón est un site archéologique de la période lithique, et un lieu de sépulture depuis l’époque Chavín (1250 à 250 av. J.-Chr.). Dès l’époque Chavín, les peuples du Pérou ancien construisaient des centres cérémoniels dirigés par une élite théocratique, et déformaient le crâne des enfants dès les premiers jours de la vie, à l’aide de moyens de pression variés. La déformation du crâne d’Ancón est une déformation antéro-postérieure oblique, brachycéphale, bilobée et asymétrique, sans trépanation ni déformation dentaire associée. C’est une variante bilobée du type Huaura de déformation crânienne, qui est associé aux régions de Chancay-Ancón et Lima. L’étude tomodensitométrique des variations d’épaisseur de la voûte, avec amincissement en regard des zones de pression, a montré que la déformation était intentionnelle, et caractérisée par une pression fronto-pariéto-temporale bilatérale surtout antérieure et dégressive d’avant en arrière, associée à une pression frontale, occipitale, et sagittale médiane. En l’absence de contexte et de datation, l’ancienneté du crâne étudié ne peut pas être précisée au long d’une période de presque trois millénaires, jusqu’à la domination Inca et l’arrivée des Espagnols (1532). Le crâne pourrait appartenir à l’une ou l’autre des cultures successives du site d’Ancón : Chavín, Baňos de Boza o Miramar, Lima, Wari, et Chancay (1200 à 1470), dont les céramiques représentent la déformation bilobée. Le crâne est probablement celui d’une femme âgée de plus de 45 ans à son décès, de statut social élevé, faisant partie de l’élite magico-religieuse, politique et économique dirigeante. L’étude de l’endocrâne a permis d’observer la déformation des veines superficielles et des lobes du cerveau. Il existe des signes de parodonpathie chronique à un stade avancé. Un abcès d’origine dentaire pourrait avoir été la cause du décès. Conclusions et perspectives : en ce qui concerne la pratique des déformations crâniennes, la région d’Ancón-Chancay et de Lima paraît être remarquable à trois égards : par le grand nombre de crânes déformés, par le grand nombre de crânes bilobés, et par la proportion importante de femmes, dont on peut supposer qu’elles étaient nées de familles nobles, et destinées dès l’enfance à faire partie de l’élite théocratique. La reconstitution 3D de l’épaisseur de la voûte crânienne a permis pour la première fois à notre connaissance de caractériser ce type de déformation, et pourrait permettre de reconstituer l’appareil déformateur. Seule la reprise des exhumations programmées sur le site d’Ancón, dans le cadre d’un projet prospectif pluridisciplinaire, pourrait permettre de mieux préciser la proportion d’individus à crâne déformé, la proportion des crânes bilobés, et le sex ratio, dans chaque contexte historique et socio-culturel de ce type de déformation crânienne intentionnelle ; et, peut-être, de retrouver in situ l’appareil déformateur correspondant. [less ▲]

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