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Search Results: 1 - 10 of 4715 matches for " Laurent Dobremez "
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Shrub encroachment in pastures in the Alps
Olivier Camacho,Laurent Dobremez,Alain Capillon
Revue de Géographie Alpine , 2009, DOI: 10.4000/rga.575
Abstract: Landscape closing due to the decline in agricultural activity is considered to be a major problem in the Alps. Abondance Valley provides a good example of this phenomenon and is also representative of a paradox commonly found in the Northern French Alps: the mountainsides and alpine pastures are still used, whereas they are becoming increasingly afforested. Environmental conditions play a major role in the localisation of agricultural land uses, but they are not sufficient to explain why pastures still in use are being invaded by shrub. Even if cutting makes it possible to effectively control the encroachment by woody species, this is not true for uncut pastures where grazing is not able to keep up with grass production. This situation is repeated every year and is the likely cause of the colonisation by woody species. To ensure their forage system and to simplify their work, farmers tend to establish grazing units that are oversized in relation to the needs of their animals. They implement compensatory practices that consist of mechanical maintenance as a complement to grazing to limit the dynamics of woody species. These labour-intensive practices are not used on all of the pastures. The analysis of farmers’ practices by agronomists is therefore a useful complement to studies of physical and socio-economic environments, at the level of the grazed field as well as at that of the valley as a whole. La dégradation des paysages par suite du recul de l’activité agricole est considérée comme un enjeu majeur dans les Alpes. La vallée d’Abondance illustre bien ce phénomène de fermeture de l’espace mais elle est en outre représentative d’un paradoxe assez répandu dans les Alpes du nord fran aises : les versants et les alpages sont encore exploités et pourtant ils se boisent progressivement. Les conditions de milieux jouent un r le majeur sur la localisation des usages agricoles de l'espace, mais elles ne peuvent pas suffire pour expliquer pourquoi l'embroussaillement gagne des prairies encore exploitées. Si la fauche permet de lutter efficacement contre l’avancée des ligneux, il n’en est pas de même dans les prairies paturées non fauchées où la capacité de prélèvement par les troupeaux s’avère faible par rapport à la production d’herbe. Cette situation se répète d’année en année et c’est la cause la plus probable de la propagation des ligneux. Pour sécuriser leur système fourrager et pour simplifier le travail, les éleveurs constituent des unités de paturage surdimensionnées par rapport aux besoins des animaux. Ils mettent en uvre des pratiques de rattrapage,
Des broussailles dans les prairies alpines
Olivier Camacho,Laurent Dobremez,Alain Capillon
Revue de Géographie Alpine , 2009, DOI: 10.4000/rga.566
Abstract: Landscape closing due to the decline in agricultural activity is considered to be a major problem in the Alps. Abondance Valley provides a good example of this phenomenon and is also representative of a paradox commonly found in the Northern French Alps: the mountainsides and alpine pastures are still used, whereas they are becoming increasingly afforested. Environmental conditions play a major role in the localisation of agricultural land uses, but they are not sufficient to explain why pastures still in use are being invaded by shrub. Even if cutting makes it possible to effectively control the encroachment by woody species, this is not true for uncut pastures where grazing is not able to keep up with grass production. This situation is repeated every year and is the likely cause of the colonisation by woody species. To ensure their forage system and to simplify their work, farmers tend to establish grazing units that are oversized in relation to the needs of their animals. They implement compensatory practices that consist of mechanical maintenance as a complement to grazing to limit the dynamics of woody species. These labour-intensive practices are not used on all of the pastures. The analysis of farmers’ practices by agronomists is therefore a useful complement to studies of physical and socio-economic environments, at the level of the grazed field as well as at that of the valley as a whole. La dégradation des paysages par suite du recul de l’activité agricole est considérée comme un enjeu majeur dans les Alpes. La vallée d’Abondance illustre bien ce phénomène de fermeture de l’espace mais elle est en outre représentative d’un paradoxe assez répandu dans les Alpes du nord fran aises : les versants et les alpages sont encore exploités et pourtant ils se boisent progressivement. Les conditions de milieux jouent un r le majeur sur la localisation des usages agricoles de l'espace, mais elles ne peuvent pas suffire pour expliquer pourquoi l'embroussaillement gagne des prairies encore exploitées. Si la fauche permet de lutter efficacement contre l’avancée des ligneux, il n’en est pas de même dans les prairies paturées non fauchées où la capacité de prélèvement par les troupeaux s’avère faible par rapport à la production d’herbe. Cette situation se répète d’année en année et c’est la cause la plus probable de la propagation des ligneux. Pour sécuriser leur système fourrager et pour simplifier le travail, les éleveurs constituent des unités de paturage surdimensionnées par rapport aux besoins des animaux. Ils mettent en uvre des pratiques de rattrapage,
L'obligation de résultat pour les mesures agri-environnementales "prairies fleuries" et "gestion pastorale" Implementation of two Agri-environment measures based on a commitment to results: the "flowering meadows" and the "pastoral management" measures
NETTIER, Baptiste ; DOBREMEZ, Laurent ; FLEURY, Philippe
Sciences Eaux & Territoires : la Revue du IRSTEA , 2012,
Abstract: Afin de répondre aux exigences de la société en faveur d'une agriculture plus respectueuse de l'environnement, un système de mesures agri-environnementales a été mis en place en Europe. Certaines permettent permettent de tester l'engagement sur des résultats. Quels en sont les intérêts et les limites, quels changements cela peut-il induire dans les exploitations agricoles ? Quelques réflexions à partir de l'étude de la mise en uvre des mesures prairies fleuries et gestion pastorale dans trois parcs naturels régionaux fran ais... Two agri-environment measures allow to test commitment to results. As farming practices are left free, it facilitates the farmers' adhesion, who see it as social recognition. But the commitment to results has also limits when agricultural and environmental objectives are incompatible or when the result is hard to control only by agricultural practices. Sharing a diagnosis and understanding objectives and constraints of the different stakeholders are then key-factors.
Attitudes des éleveurs et sensibilité des systèmes d'élevage face aux sécheresses dans les Alpes fran aises
Laurent Dobremez,Baptiste Nettier,Jean-Luc Coussy,Thomas Romagny
Revue de Géographie Alpine , 2011, DOI: 10.4000/rga.1294
Abstract: Les systèmes d'élevage des Alpes fran aises sont fortement exposés au changement climatique annoncé et la plupart subissent déjà des épisodes de sécheresse depuis le début des années 2000. Face à ces aléas, les éleveurs ont mis en uvre un certain nombre de leviers et envisagent d'en activer d'autres à l'avenir. Des enquêtes en exploitation ont permis d’identifier ces leviers. Leur analyse permet de caractériser les attitudes des éleveurs face aux sécheresses et d’évaluer l’évolution de la sensibilité de leurs systèmes d’élevage. A l'exception des exploitations disposant de surfaces irriguées importantes, toutes les exploitations cherchent d'abord à contourner l’aléa. Elles ont recours aux achats de fourrage pour compenser la baisse des récoltes destinées aux stocks hivernaux, mais à des degrés divers selon la durée de l’hivernage. Pour les périodes de paturage, les éleveurs de haute montagne et les systèmes laitiers des Alpes du nord jouent avant tout sur un système résistant grace à l’agrandissement et au surdimensionnement des patures par rapport aux besoins du troupeau. Les exploitations pastorales des Alpes du sud misent aussi sur une diversité de surfaces et une certaine latitude dans la conduite technique pour s'adapter aux conditions de l'année. Une succession répétée d’années sèches pourrait se traduire par des ruptures plus radicales dans les systèmes d’élevage. Il faut aussi garder à l’esprit que le changement climatique n'est qu'un des facteurs influen ant les modes de transformation des exploitations. Livestock farming systems in the French Alps are particularly exposed to the predicted climate change and most of them have already experienced periods of drought since the beginning of the 2000s. Faced with this risk, livestock farmers have put in place a certain number of measures and envisage introducing others in the future. For the present study, surveys were conducted among livestock farmers to identify these measures and analyses were carried out to characterise the attitudes of livestock farmers to drought conditions and to evaluate changes in the sensitivity of their livestock farming systems. With the exception of those farms with extensive irrigated areas, all the farms are seeking solutions to deal with the risks arising from droughts. One solution is to purchase fodder to compensate for the decrease in the harvests that normally provide animal feed in the winter; the amounts purchased vary with the length of wintering required. For the grazing periods, the high mountain livestock breeders and the dairy systems of the Northern Alps
Attitudes of livestock farmers and sensitivity of livestock farming systems to drought conditions in the French Alps
Laurent Dobremez,Baptiste Nettier,Jean-Luc Coussy,Thomas Romagny
Revue de Géographie Alpine , 2011, DOI: 10.4000/rga.1307
Abstract: Livestock farming systems in the French Alps are particularly exposed to the predicted climate change and most of them have already experienced periods of drought since the beginning of the 2000s. Faced with this risk, livestock farmers have put in place a certain number of measures and envisage introducing others in the future. For the present study, surveys were conducted among livestock farmers to identify these measures and analyses were carried out to characterise the attitudes of livestock farmers to drought conditions and to evaluate changes in the sensitivity of their livestock farming systems. With the exception of those farms with extensive irrigated areas, all the farms are seeking solutions to deal with the risks arising from droughts. One solution is to purchase fodder to compensate for the decrease in the harvests that normally provide animal feed in the winter; the amounts purchased vary with the length of wintering required. For the grazing periods, the high mountain livestock breeders and the dairy systems of the Northern Alps rely above all on extending and over-sizing the pasture areas in relation to the needs of the herds. The livestock farms of the Southern Alps also rely on the diversity of vegetation areas and a certain flexibility in the practices used to adapt to conditions experienced during the year. A succession of dry years could result in more radical breakdowns in the livestock systems. It should also be remembered that climate change is only one of the factors influencing the types of changes taking place on farms. Les systèmes d'élevage des Alpes fran aises sont fortement exposés au changement climatique annoncé et la plupart subissent déjà des épisodes de sécheresse depuis le début des années 2000. Face à ces aléas, les éleveurs ont mis en uvre un certain nombre de leviers et envisagent d'en activer d'autres à l'avenir. Des enquêtes en exploitation ont permis d’identifier ces leviers. Leur analyse permet de caractériser les attitudes des éleveurs face aux sécheresses et d’évaluer l’évolution de la sensibilité de leurs systèmes d’élevage. A l'exception des exploitations disposant de surfaces irriguées importantes, toutes les exploitations cherchent d'abord à contourner l’aléa. Elles ont recours aux achats de fourrage pour compenser la baisse des récoltes destinées aux stocks hivernaux, mais à des degrés divers selon la durée de l’hivernage. Pour les périodes de paturage, les éleveurs de haute montagne et les systèmes laitiers des Alpes du nord jouent avant tout sur un système résistant grace à l’agrandissement et au sur
Marine Biology: A Sub-Sample of a Vast Topic  [PDF]
Laurent Seuront
Open Journal of Marine Science (OJMS) , 2013, DOI: 10.4236/ojms.2013.32A001
Abstract:

Marine Biology: A Sub-Sample of a Vast Topic

Generalized Powers of Substitution with Pre-Function Operators  [PDF]
Laurent Poinsot
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.47A004
Abstract:

An operator on formal power series of the form S \"\" μS , where μ is an invertible power series, and σ is a series of the form t+\"\"(t2) is called a unipotent substitution with pre-function. Such operators, denoted by a pair (μ σ )  , form a group. The objective of this contribution is to show that it is possible to define a generalized powers for such operators, as for instance fractional powers \"\"σ for every\"\" .

The Mediating Role of the Sense of Relatedness and Task Cohesion in the Relation between Psychological Power Distance and Efficicency of a Working Team  [PDF]
Laurent Auzoult
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.410105
Abstract:

Understanding of the effectiveness of work-teams is a major issue in the business world, where they are expected to facilitate developing individual skills and increasing organizations’ efficiency. Eighty-three engineers working in teams have responded to a questionnaire devised to measure perceptual power distances, the sense of relatedness, cohesion measured by integration around the task, and teams’ effectiveness. Results reveal that “task cohesion” and sense of relatedness mediate the relationship between power distance and perceived effectiveness. These results are related with those observed in the context of the self-determination theory and presented in order to highlight their practical implications.

Health 3.0—The patient-clinician “arabic spring” in healthcare  [PDF]
Serge Gagnon, Laurent Chartier
Health (Health) , 2012, DOI: 10.4236/health.2012.42008
Abstract: A growing number of citizen-patients and clinicians use Communication and Self-Managed Health Technologies (CSMHT) in their relationship. Doing so, they shift from the current paradigm of dependency to a co-responsibility paradigm in healthcare. Facing the runaway utilization of health services, we need to think “outside the box” to unblock the system. A Health 3.0 development model of governance that position patients as primary members of the clinicians’ team is presented to map this institutional transformation. At the practical level, an MD 3.0 relational model and a Citizen-Patient 3.0 behavioral profile are presented.
Deploying Safety-Critical Applications on Complex Avionics Hardware Architectures  [PDF]
Robert Hilbrich, Laurent Dieudonné
Journal of Software Engineering and Applications (JSEA) , 2013, DOI: 10.4236/jsea.2013.65028
Abstract:

Aviation electronics (avionics) are sophisticated and distributed systems aboard an airplane. The complexity of these systems is constantly growing as an increasing amount of functionalities is realized in software. Thanks to the performance increase, a hardware unit must no longer be dedicated to a single system function. Multicore processors for example facilitate this trend as they are offering an increased system performance in a small power envelope. In avionics, several system functions could now be integrated on a single hardware unit, if all safety requirements are still satisfied. This approach allows for further optimizations of the system architecture and substantial reductions of the space, weight and power (SWaP) footprint, and thus increases the transportation capacity. However, the complexity found in current safety-critical systems requires an automated software deployment process in order to tap this potential for further SWaP reductions. This article used a realistic flight control system as an example to present a new model-based methodology to automate the software deployment process. This methodology is based on the correctness-by-construction principle and is implemented as part of a systems engineering toolset. Furthermore, metrics and optimization criteria are presented which further help in the automatic assessment and refinement of a generated deployment. A discussion regarding a tighter integration of this approach in the entire avionics systems engineering workflow concludes this article.

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