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See detailQuantifying landscape anthropisation patterns: concepts, methods and limits
Vranken, Isabelle ULg

Doctoral thesis (2015)

Since human beings began to use and shape the land, their influence on their environment has kept on growing so that little or no ecosystem in the world is now considered as untouched. This induces ... [more ▼]

Since human beings began to use and shape the land, their influence on their environment has kept on growing so that little or no ecosystem in the world is now considered as untouched. This induces pressures on ecosystem health and land scarcity. Africa is of particular concern because it still presents broad undisturbed zones and key ecosystem services, despite being submitted to increasing anthropogenic pressures. Landscape ecology appears suitable for the study of such phenomena, thanks to its spacebased integrative nature and geographical level of focus. It studies the impact of spatial pattern transformation — especially heterogeneity and its components — on ecological processes and provides powerful analytical tools of landscape anthropisation. The main objective of this thesis is to organise the concepts and methods, from landscape ecology and related disciplines, into a consistent logic, to pinpoint missing analytical frameworks for response-oriented anthropisation assessment, and to apply them to African cases to explore the spatial patterns of anthropisation. In order to address landscape anthropisation, we assemble diverse disciplines into a logical network (DPSIR). The new theoretical framework is tested on Lubumbashi (DRC). In order to address spatial patterns, we first evaluate the thermodynamic connection of the term entropy in landscape ecology: spatial heterogeneity, unpredictability and scale influence. Then, based on 20 landscapes, we highlight the complex relationship between spatial heterogeneity and landscape anthropisation. We finally use the modelled relationships to test the anthropogenic origin of the spatial pattern of a land cover class in Lubumbashi. The main results of this research show that several concepts are used to describe different aspects of anthropisation and that its quantification strongly depends on the reference states. Data formats can be combined into a new assessment method ensuring more precision and comparability, but a good field knowledge is required. As for heterogeneity, the existing definitions of landscape entropy follow the logic of thermodynamics or information theory, that are not compatible. Only unpredictability could be properly interpreted in thermodynamic terms if energy transfer measurements were performed at the appropriate level. The anthropogenic effects on heterogeneity completely diverge depending on the amount of already anthropised surface, on the land cover type (natural or anthropogenic), and on the heterogeneity components. The aforementioned findings could be adapted to include functional aspects and better address the relationship between spatial pattern and ecological processes. Such integration would help designing response actions that can recommend human activities and spatial patterns that could optimise the use of land to ensure ecological functioning while supporting human development. [less ▲]

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See detailContribution à l’étude de la dynamique de l’élevage pastoral au Niger : cas de la région de Diffa
Laouali, Abdoulkadri ULg

Doctoral thesis (2015)

In the Sahelian countries where extensive pastoral breeding is practiced, livestock plays an essential role in the socio-economic and dietary balance of the households. However, throughout the literature ... [more ▼]

In the Sahelian countries where extensive pastoral breeding is practiced, livestock plays an essential role in the socio-economic and dietary balance of the households. However, throughout the literature, this activity was submitted to various controversies including its contribution to the degradation of the environment; greenhouse gas emissions; its weak economic performance; etc. But other studies have noted the importance and efficiency of pastoral practice in a precarious natural environment such as the Republic of Niger, great stockbreeding country in the heart of the Sahel, with a herd of over 37 million heads. Thus, this research has tried to reposition the debate by emphasizing the role and importance of pastoral breeding in the Sahelian countries in general, particularly in Niger and specifically in the region of Diffa. Located between the desert zone in the North and the Sahelian zone in the South, the Region of Diffa is a pastoral area par excellence in Niger. Breeding, with a highly diversified livestock, is the dominant economic activity in the region. It concerns 95% of the population and contributes annually to 55% of the regional gross domestic product. However, this activity is submitted to various constraints, particularly biophysical and anthropogenic. In order to understand the pastoral dynamics in this region, a research work was initiated starting in 2010 and following a systemic approach. The work was built around three poles: Man-Natural Resources-Animals. A survey of 300 households (150 households with a sedentary herd and 150 with a mobile herd) was conducted during the first semester of 2012. Investigations were made on the basis of the prior identification of three agro-ecological zones (pastoral bowls, Komadougou River, Lake Chad) based on 100 households for each zone. The research results revealed that pastoral breeding in the region of Diffa is mutating. Herds (sedentary and mobile) are relatively small sized and increasingly composed in majority by small ruminants. The reproduction is carried out by a core of female spawners more or less stable and dominated by younger ones. Data cross analysis highlights the occurrence of recurrent fodder deficits, attributable to a series of annual rainfall deficits as well as animal diseases as the main causes of changing pastoral breeding in the region of Diffa. To deal with these problems the pastoral and agro-pastoral populations have built and developed a set of adaptive strategies to resist shocks and to mitigate their effects and to ensure the survival of households and livestock. However, over the years and the recurrence of shocks, traditional strategies for managing risks and uncertainties are being weakened with socio-economic consequences in pastoral and agro-pastoral households. An Intervention of the State, NGOs and / or associations and other development partners, would boost these strategies and strengthen the capacity of households to manage risk in the long term. [less ▲]

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See detailCover Songs Retrieval and Identification
Osmalsky, Julien ULg

Conference (2015, February 24)

Cover songs retrieval is a MIR task that has been widely studied in the recent years. The task, in its general sense, consists in retrieving covers for a given audio query. In this PhD, we focus on the ... [more ▼]

Cover songs retrieval is a MIR task that has been widely studied in the recent years. The task, in its general sense, consists in retrieving covers for a given audio query. In this PhD, we focus on the more specific task of cover songs *identification*. Given an unknown cover song query, we want to find relevant information about the original song, such as the title, the artist etc. Applications are live music recognition, plagiarism detections, query by examples, etc. Our approach is based on a pruning algorithm, whose role is to discard as quickly as possible as many tracks as possible from a search database in order to keep a smaller subset that should contain the tracks relevant to the query. We introduce the concept of *rejectors* for the pruning algorithm, which are single or combined classifier using multiple audio features for selecting relevant tracks. [less ▲]

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See detailResonant and antiresonant bouncing droplets
Hubert, Maxime ULg; Robert, Damien; Caps, Hervé ULg et al

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2015), 91

When placed onto a vibrating liquid bath, a droplet may adopt a permanent bouncing behavior, depending on both the forcing frequency and the forcing amplitude. The relationship between the droplet ... [more ▼]

When placed onto a vibrating liquid bath, a droplet may adopt a permanent bouncing behavior, depending on both the forcing frequency and the forcing amplitude. The relationship between the droplet deformations and the bouncing mechanism is studied experimentally and theoretically through an asymmetric and dissipative bouncing spring model. Antiresonance phenomena are evidenced. Experiments and theoretical predictions show that both resonance at specific frequencies and antiresonance at Rayleigh frequencies play crucial roles in the bouncing mechanism. In particular, we show that they could be exploited for bouncing droplet size selection. [less ▲]

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See detailA propos des fonctions continues nulle part dérivables
Esser, Céline ULg

Conference (2015, February 24)

En 1872, Karl Weierstrass choqua la communauté mathématique en présentant une famille de fonctions continues nulle part dérivables. Après la publication de ce résultat, beaucoup d'autres mathématiciens ... [more ▼]

En 1872, Karl Weierstrass choqua la communauté mathématique en présentant une famille de fonctions continues nulle part dérivables. Après la publication de ce résultat, beaucoup d'autres mathématiciens apportèrent leur propre contribution en construisant d'autres fonctions continues et nulle part dérivables. Dans cet exposé, nous présenterons les fonctions de Weierstrass. De plus, nous montrerons que le th eorème de Baire permet d'affirmer que l'ensemble des fonctions nulle part dérivables est dense dans l'ensemble des fonctions continues. Nous étudierons également la régularité ponctuelle de telles fonctions en utilisant la notion d'exposant de Hölder. [less ▲]

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See detailTwo-Photon Luminescence of Gold Nanorods Mediated by Higher Order Plasmon Modes
Verellen, Niels; Denkova, Denitza; De Clercq, Ben et al

in ACS Photonics (2015), 2

Metallic nanorod antennas can be considered as an analogue to classical half-wave dipole antennas, constituting an important tool for manipulating linear and nonlinear lightmatter interactions in ... [more ▼]

Metallic nanorod antennas can be considered as an analogue to classical half-wave dipole antennas, constituting an important tool for manipulating linear and nonlinear lightmatter interactions in nanoscale volumes. Using two-photon luminescence (TPL) scanning laser microscopy, we investigate such optical antennas beyond their fundamental dipole mode. The antenna mode dispersion is extracted from the nonlinear TPL measurement and reveals a TPL process that is dominated by plasmon-induced enhancement of the two photon absorption in the metal. Additionally, a clear signature of the mode parity is observed in the TPL images. TPL maxima are observed outside the antenna boundaries for even parity modes, whereas they are located inside for odd modes. It is concluded that for even modes the two-photon luminescence emission is strongly mediated by retardation of the excitation field, a consequence of their zero net-dipole moment. This selective excitation of different mode parities is highly relevant for nanoscale enhanced nonlinear optics, as well as plasmonic nanosensor applications and tuning of radiative properties of quantum emitters. [less ▲]

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See detailInorhanic and organic carbon spatial variability in the Congo River during high waters (December 2013) and low waters (June 2014)
Borges, Alberto ULg; Bouillon, S; Teodoru, C et al

Conference (2015, February 23)

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See detailBiologie du développement (partim. animal)
Peers, Bernard ULg

Learning material (2015)

Detailed reference viewed: 37 (1 ULg)
See detailMédiations numériques de la lecture
Barnabé, Fanny ULg

Scientific conference (2015, February 23)

Séance de séminaire sur la médiation que représente le numérique dans la lecture littéraire.

Detailed reference viewed: 15 (2 ULg)
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See detailSolidarities and Learning: Reporting Incidents in a Nuclear Research Center
Rossignol, Nicolas ULg

Scientific conference (2015, February 23)

Detailed reference viewed: 7 (0 ULg)
See detailLes plantes qui nous soignent : de la tradition à la médecine moderne
Frederich, Michel ULg

Scientific conference (2015, February 23)

Detailed reference viewed: 10 (2 ULg)
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See detailPenser le vieillissement de la population pour la Wallonie de demain
Delvenne, Pierre ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 24 (1 ULg)
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See detailPlankton diversity and metabolism in the Congo River during high waters (December 2013) and low waters (June 2014)
Darchambeau, François ULg; Descy, JP; Leporcq, B et al

Poster (2015, February 22)

Detailed reference viewed: 9 (1 ULg)
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See detailSediment and carbon dynamics in a tropical river-floodplain system during high-discharge conditions (Tana River, Kenya)
Geeraert, N; Omengo; Borges, Alberto ULg et al

Conference (2015, February 22)

Detailed reference viewed: 12 (0 ULg)
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See detailEMODnet regional gridded abundance products: a tool to facilitate ecosystem assessments
Beckers, Jean-Marie ULg

Scientific conference (2015, February 20)

Detailed reference viewed: 8 (0 ULg)
See detailFAO Training in Crop Yield Forecasting - Remote Sensing - Method for Crop Yield Forecasting System (CYFS) from spatial Remote Sensing for Tajikistan. Integration of PROBA-V NDVI images. Belgium - Arlon Campus Environment - January 2015.
Denis, Antoine ULg

Learning material (2015)

This manual has been written for the “Training for strengthening crop yield forecasting capacity of the State Administration for Hydrometeorology (Hydromet) of Tajikistan” that occurred between 12nd ... [more ▼]

This manual has been written for the “Training for strengthening crop yield forecasting capacity of the State Administration for Hydrometeorology (Hydromet) of Tajikistan” that occurred between 12nd January and 7th February 2015 in Arlon – Belgium in the framework of the Food and Agriculture Organization (FAO) of the United Nations Project (GCP/TAJ/007/EC) “Support to Strengthening the National Food Security Information System in Tajikistan”. This manual is intended to cover the Remote Sensing part only of the general Crop Yield Forecasting System (CYFS). Despite written for the Tajik context this manual can serve as an example for all other countries. This manual follows on from the 2 manuals entitled: 1) “FAO Training in Crop Yield Forecasting ARMENIA - Erevan – May 2011 – Remote Sensing”. 2) “FAO Training in Crop Yield Forecasting. Improvement of the Crop Yield Forecasting System (CYFS) in Armenia: a new approach for satellite data integration. ARMENIA - Yerevan - January 2013.” This manual, in addition to adapt the method to Tajik context, integrates for the first time the NDVI images of PROBA-V satellite. These images continue the stopped SPOT-VEGETATION time’s series, from 2014 to undefined future. [less ▲]

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Peer Reviewed
See detailRational Development of an Attenuated Recombinant Cyprinid Herpesvirus 3 Vaccine Using Prokaryotic Mutagenesis and In Vivo Bioluminescent Imaging
Boutier, Maxime ULg; Ronsmans, Maygane ULg; Ouyang, Ping et al

in PLoS Pathogens (2015), 11(2), 1004690

Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We ... [more ▼]

Cyprinid herpesvirus 3 (CyHV 3) is causing severe economic losses worldwide in common and koi carp industries, and a safe and efficacious attenuated vaccine compatible with mass vaccination is needed. We produced single deleted recombinants using prokaryotic mutagenesis. When producing a recombinant lacking open reading frame 134 (ORF134), we unexpectedly obtained a clone with additional deletion of ORF56 and ORF57. This triple deleted recombinant replicated efficiently in vitro and expressed an in vivo safety/efficacy profile compatible with use as an attenuated vaccine. To determine the role of the double ORF56-57 deletion in the phenotype and to improve further the quality of the vaccine candidate, a series of deleted recombinants was produced and tested in vivo. These experiments led to the selection of a double deleted recombinant lacking ORF56 and ORF57 as a vaccine candidate. The safety and efficacy of this strain were studied using an in vivo bioluminescent imaging system (IVIS), qPCR, and histopathological examination, which demonstrated that it enters fish via skin infection similar to the wild type strain. However, compared to the parental wild type strain, the vaccine candidate replicated at lower levels and spread less efficiently to secondary sites of infection. Transmission experiments allowing water contamination with or without additional physical contact between fish demonstrated that the vaccine candidate has a reduced ability to spread from vaccinated fish to naïve sentinel cohabitants. Finally, IVIS analyses demonstrated that the vaccine candidate induces a protective mucosal immune response at the portal of entry. Thus, the present study is the first to report the rational development of a recombinant attenuated vaccine against CyHV 3 for mass vaccination of carp. We also demonstrated the relevance of the CyHV 3 carp model for studying alloherpesvirus transmission and mucosal immunity in teleost skin. [less ▲]

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See detailTransient internally driven aurora at Jupiter discovered by Hisaki and the Hubble Space Telescope
Kimura, Tomoki; Badman, Sarah; Tao, Chihiro et al

in Geophysical Research Letters (2015), 42

Jupiter’s auroral emissions reveal energy transport and dissipation through the planet’s giant magnetosphere. While the main auroral emission is internally driven by planetary rotation in the steady state ... [more ▼]

Jupiter’s auroral emissions reveal energy transport and dissipation through the planet’s giant magnetosphere. While the main auroral emission is internally driven by planetary rotation in the steady state, transient brightenings are generally thought to be triggered by compression by the external solar wind. Here we present evidence provided by the new Hisaki spacecraft and the Hubble Space Telescope that shows that such brightening of Jupiter’s aurora can in fact be internally driven. The brightening has an excess power up to ~550 GW. Intense emission appears from the polar cap region down to latitudes around Io’s footprint aurora, suggesting a rapid energy input into the polar region by the internal plasma circulation process. [less ▲]

Detailed reference viewed: 33 (12 ULg)