Modelling climate control on cropland and grassland development using phenologically tuned variables

in Geophysical Research Abstracts (2010), 12

Many studies already investigated the impact of climate change and climate variability on vegetation at global and continental scales. Using time series of remote sensing and climate data, Nemani et al ... [more ▼]

Many studies already investigated the impact of climate change and climate variability on vegetation at global and continental scales. Using time series of remote sensing and climate data, Nemani et al. (2003) analyzed trends in Net Primary Production in relation with changes in climate and showed that, between 1982 and 1999, primary productivity increased by 6% globally in response to climate change. This study also stressed the need to take into account the spatial variability of climatic constraints to plant growth when analyzing the climate change impact on vegetation. Others authors described different phenomenon linked with climate change such as increases of seasonal NDVI amplitude and growing season duration in the Northern high latitude or changes in circumpolar photosynthetic activities. Understanding the interactions between climate and vegetation is also a key issue in our PhD research. Our objective is to identify the meteorological factors which limit the development of croplands and grasslands in relation with their geographical localization. For that purpose, we acquired 10-daily time series of the Normalized Difference Vegetation Index, NDVI, derived from SPOT-VEGETATION and 7 meteorological parameters (Tmean, Tmin, Tmax, Rain, Rad, ETP, Rain-ETP) derived from ERA40 re-analyses and the operational ECMWF (European Centre for Medium-Range Weather Forecast) atmospheric model. Cross-correlations between NDVI and each one of the meteorological parameters were analysed for a set of 25 regions over Europe and Africa: 15 agricultural regions and 10 regions covered by grassland or savannas. Unlike others studies, we did not consider the vegetation globally but we focussed on two types of vegetation: croplands and grasslands. This is quite important considering the role of phenology on the vegetation cycle and its relation with climate. Moreover the analysis was not realised using yearly estimates but using 10-daily products. In order to avoid stationarity related issue, a specific methodology was developed taking into account the phenological cycle of the vegetation under consideration. Preliminary results showed that the relation between a meteorological limiting factor, e.g. precipitation, and NDVI can not be considered as linear during the year or even during the growing season. Interactions must to be studied at a smaller time scale than the growing season in order to identify properly the limiting factors to plant growth taking into account its phenology. Moreover the main limiting factors are variable from a region to another. In our analysis we also considered the possibility of a delayed response of the vegetation or a cumulated effect of meteorological events (up to 3 months). Our methodology will be presented during the conference and results will be discussed and illustrated by some test cases. [less ▲]

Imagerie fonctionnelle et audition.

in Cahiers de l'Audition (Les) (2010)

Recent Behavior of the North Anatolian Fault: Insights from an Integrated Paleoseismological Dataset

in Journal of Geophysical Research (2010), 115(B09316),

The North Anatolian Fault (NAF) is a right‐lateral plate boundary fault that arcs across northern Turkey for ∼1500 km. Almost the entire fault progressively ruptured in the 20th century, its cascading ... [more ▼]

The North Anatolian Fault (NAF) is a right‐lateral plate boundary fault that arcs across northern Turkey for ∼1500 km. Almost the entire fault progressively ruptured in the 20th century, its cascading style indicating that stress from one fault rupture triggers fault rupture of adjacent segments. Using published paleoseismic investigations, this study integrates all of the existing information about the timing of paleoearthquakes on the NAF. Paleoseismic investigation data are compiled into a database, and for each site a Bayesian, ordering‐constrained age model is constructed in a consistent framework. Spatial variability of recurrence intervals suggests a spatial pattern in the behavior of earthquakes on the NAF that may correspond to the tectonic provinces within the Anatolian plate. In the west, the shear stress associated with the escaping Anatolian plate interplays with the tensile stress associated with the Aegean extensional province. Along this western transtensional section we recognize short recurrence intervals and switching between the furcated fault strands. The central section of the NAF is translational with little influence of fault‐normal stresses from other tectonic sources. This section tends to rupture in unison or close succession. The eastern section of the NAF is transpressional due to the compressional fault‐normal stress associated with the indenting Arabian plate. Along this section the recurrence intervals are bimodal, which we attribute to variable normal stress, although there are other possible causes. [less ▲]

Pneumopathies organisées: à propos de 3 cas

in Revue Médicale de Liège (2010), 65(10), 549-55

Infiltrative lung lesions are not always linked to infectious processes or cancers. An interesting entity, the OP (Organizing Pneumonia) or COP (Cryptogenic Organizing Pneumonia)--formerly BOOP ... [more ▼]

Infiltrative lung lesions are not always linked to infectious processes or cancers. An interesting entity, the OP (Organizing Pneumonia) or COP (Cryptogenic Organizing Pneumonia)--formerly BOOP (Bronchiolitis Obliterans Organizing Pneumonia)--is discussed through observations repor. ted in this article. We provide some keys to allow the astute observer to target this often curable disease. [less ▲]

The permease gene nagE2 is the key to N-acetylglucosamine sensing and utilization in Streptomyces coelicolor and is subject to multi-level control

in Molecular Microbiology (2010), 75((5)), 1133-44

Facing towards epidermal stem cells (Review).

in International Journal of Molecular Medicine (2010), 26(2), 171-4

Skin contains somatic stem cells that generate keratinocyte, melanocyte and mesenchymal cell lineages. These somatic stem cells have traditionally been thought to be restricted in their differentiation ... [more ▼]

Skin contains somatic stem cells that generate keratinocyte, melanocyte and mesenchymal cell lineages. These somatic stem cells have traditionally been thought to be restricted in their differentiation and regeneration potential to the tissues in which they reside. This review focused on epidermal stem cells (ESCs). These cells are distinguished from transitory amplifier cells and post-mitotic cells. ESC are found in the interadnexal epidermis and in the bulge region of hair follicles. A series of ESCs markers are available, but increased sensitivity and specificity require further development. [less ▲]

Isomorphism and microfinance: an institutional analysis of the evolution of microfinance in Peru

Conference (2010)

De la ciudad letrada a la selva. Acerca de Mascarita y de Marcos.

in Idmhand, Fatiha; Dei Cas, Norah (Eds.) El escritor y el intelectual entre dos mundos. Lugares y figuras del desplazamiento. Homenaje a Fernando Aínsa (2010)

Water table mapping using Bayesian data fusion with auxiliary data

in Water 2010 symposium, International Symposium on Stochastic Hydraulics (2010)

Water table elevations are usually sampled in space using piezometric measurements, that are unfortunately both expensive to drill and monitor and consequently are thus scarce over space. Most of the time ... [more ▼]

Water table elevations are usually sampled in space using piezometric measurements, that are unfortunately both expensive to drill and monitor and consequently are thus scarce over space. Most of the time, piezometric data are sparsely distributed over large areas, thus providing limited direct information about the level of the corresponding water table. As a consequence, there is a real need for approaches that are able at the same time to (i) provide spatial predictions at unsampled locations and (ii) enable the user to account in a meaningful way for all potentially available secondary information sources that are in some way related to water table elevations. Advantages of these auxiliary information sources are their cheapest prices and their better spatial coverage, thus allowing the user to improve the quality of subsequent mapping provide that a meaningful way of merging these data is made available. In this paper, a recently developed Bayesian Data Fusion technique (BDF) is applied to the problem of water table spatial mapping. After a brief presentation of the underlying theory, specific assumptions are made and discussed in order to account for a digital elevation model as well as for the geometry of a corresponding river network. Based on a data set for the Dyle basin in the north part of Belgium, the suggested model is then implemented by accounting for two secondary information sources, i.e., a spatially exhaustive high resolution digital elevation model and a metric allowing us to account for the whole geometry of the river network as auxiliary information. Results are compared to those of standard spatial mapping techniques like ordinary kriging and cokriging. Respective accuracies and precisions of these estimators are finally evaluated using a leave-one-out cross-validation procedure. They show one one side the obvious benefit of incorporating additional information sources, but more interesting they also emphasize the limitations of traditional multivariate methods (like, e.g., cokriging methods) that fail to efficiently take benefit of these addditional information due to restrictive modeling hypotheses, whereas BDF has no difficulty on that side. Though the BDF methodology was illustrated here for the integration of only two secondary information sources, the method can also be applied for incorporating an arbitrary number of auxiliary variables. It has also been successfully applied in other fields like remote-sensing and air pollution, thus opening new avenues for the important and general topic of data integration in a spatial mapping context. Extension towards a space-time context for dynamic mapping is also possible. [less ▲]

Biotechnological applications of psychrophiles

in Environmental Technology (2010), 31