Space-Time Adaptive Processing (STAP): an Overview

Scientific conference (2003)

Space-variant holographic interconnections in dichromated gelatin

in Proceedings of OPTO 92 (1992, April 14)

Spajdel Ch., Dufrêne M., Waeyenbergh M. & Lebrun Ph. 1997. Conséquences de la relation entre la Cétoine dorée (Cetonia aurata Linné, 1761) et le complexe des fourmis rousses (Formica rufa Linné, 1763 et Formica polyctena Linné, 1763) pour la définition d'une stratégie de gestion de ces espèces protégées en Wallonie.

in Les cahiers des Réserves Naturelles RNOB (1997), 11

Sparc-like protein 1 is a new marker of human glioma progression.

in Journal of Proteome Research (2012), 11(10), 5011-21

High-grade gliomas (glioblastomas) are the most common and deadly brain tumors in adults, currently with no satisfactory treatment available. Apart from de novo glioblastoma, it is currently accepted that ... [more ▼]

High-grade gliomas (glioblastomas) are the most common and deadly brain tumors in adults, currently with no satisfactory treatment available. Apart from de novo glioblastoma, it is currently accepted that these malignancies mainly progress from lower grade glial tumors. However, the molecular entities governing the progression of gliomas are poorly understood. Extracellular and membrane proteins are key biomolecules found at the cell-to-cell communication interface and hence are a promising proteome subpopulation that could help understand the development of glioma. Accordingly, the current study aims at identifying new protein markers of human glioma progression. For this purpose, we used glial tumors generated orthotopically with T98G and U373 human glioma cells in nude mice. This setup allowed also to discriminate the protein origin, namely, human (tumor) or mouse (host). Extracellular and membrane proteins were selectively purified using biotinylation followed by streptavidin affinity chromatography. Isolated proteins were digested and then identified and quantified employing 2D-nano-HPLC-MS/MS analysis. A total of 23 and 27 up-regulated extracellular and membrane proteins were identified in the T98G and U373 models, respectively. Approximately two-thirds of these were predominantly produced by the tumor, whereas the remaining proteins appeared to be mainly overexpressed by the host tissue. Following extensive validation, we have focused our attention on sparc-like protein 1. This protein was further investigated using immunohistochemistry in a large collection of human glioma samples of different grades. The results showed that sparc-like protein 1 expression correlates with glioma grade, suggesting the possible role for this protein in the progression of this malignancy. [less ▲]

Sparing methylation of β-cyclodextrin mitigates cytotoxicity and permeability induction in respiratory epithelial cell layers in vitro

in Journal of Controlled Release (2009), 136

Cyclodextrins (CDs) are promising solubility enhancers for inhaled drug delivery. However, they have dose-dependent effects on the respiratory epithelium, which may have advantages for permeability ... [more ▼]

Cyclodextrins (CDs) are promising solubility enhancers for inhaled drug delivery. However, they have dose-dependent effects on the respiratory epithelium, which may have advantages for permeability enhancement but also gives rise to safety concerns. In this study, the methyl thiazol tetrazolium (MTT) assay was used to compare a new sparingly methylated β-CD, Kleptose® Crysmeβ (Crysmeb) with the more established CD derivatives hydroxypropyl-γ-cyclodextrin (HPγCD), randomly methylated β-cyclodextrin (Rameb) and hydroxypropyl-β-cyclodextrin (HPβCD). The βCD derivatives affected cell metabolism in A549 cells in a concentration dependent manner with LDso of 56, 31 and 11 mM obtained for HPβCD, Crysmeb and Rameb, respectively. Calu-3 cells were less susceptible to βCD with an LDso of 25 mM being obtained for Rameb only. Permeability increases in Calu-3 cell layers were observed with βCD derivatives and a concentration dependency shown. The mechanism of permeability enhancement and its reversibility was investigated. Rameb produced an irreversible loss of cell layer barrier function at ≥25 mM, but perturbations of epithelial integrity were moderate and reversible in the case of HPβCD and Crysmeb (25-50 mM). Given its high solubilisation capacity, the low toxicity and transient absorption promoting properties, this study identifies Crysmeb as a promising adjuvant in formulations for inhalation. [less ▲]

A Sparse Estimation Approach to Fault Isolation

in Proceedings of the ASME Turbo Expo 2009 (2009, June)

Least-squares-based methods are very popular in the jet engine community for health monitoring purpose. In most practical situations, the number of health parameters exceeds the number of measurements ... [more ▼]

Least-squares-based methods are very popular in the jet engine community for health monitoring purpose. In most practical situations, the number of health parameters exceeds the number of measurements, making the estimation problem underdetermined. To address this issue, regularisation adds a penalty term on the deviations of the health parameters. Generally, this term imposes a quadratic penalisation on these deviations. A side-effect of this technique is a relatively poor isolation capability. The latter feature can be improved by recognizing that abrupt faults impact at most one or two component(s) simultaneously. This translates mathematically into the search for a sparse solution. The present contribution reports the development of a fault isolation tool favouring sparse solutions. It is very efficiently implemented in the form of a quadratic program. As a validation procedure, the resulting algorithm is applied to a variety of fault conditions simulated with a generic commercial turbofan model. [less ▲]

Sparse Two-Row Cuts and an Algorithm for the Separation Problem

Conference (2010, July)

We propose a systematic way to generate sparse cuts from multiple rows of the simplex tableau. We also discuss the question of separation for a multi-row model. To this end, we consideer the polar system ... [more ▼]

We propose a systematic way to generate sparse cuts from multiple rows of the simplex tableau. We also discuss the question of separation for a multi-row model. To this end, we consideer the polar system allowing to generate valid inequalities. In order to avoid generating the large number of constraints of the polar, we consider a reduced version of it that we dynamically extend. Checking the validity of an inequality is done geometrically. Computational results showing the efficiency of the algorithm are presented. This is a joint work with Laurent Poirrier. [less ▲]

Spasmogenic action of endothelin-1 on isolated equine pulmonary artery and bronchus

in Equine Veterinary Journal (2003), 35(2), 190-6

Reasons for performing study: There is currently little published information about the effects of endothelin-1 (ET-1), a potent endogenous spasmogen of vascular and airway smooth muscle, on pulmonary ... [more ▼]

Reasons for performing study: There is currently little published information about the effects of endothelin-1 (ET-1), a potent endogenous spasmogen of vascular and airway smooth muscle, on pulmonary vasculature and airways or which ET receptor subtypes mediate ET-1 induced vasoconstrictive and bronchoconstrictive action in the horse. Objectives: To investigate the effect of endothelin-1 (ET-1) on smooth muscle from isolated equine pulmonary artery and bronchus. In addition, the roles of ETA and ETB receptors in ET-1 mediated contraction in these tissues were assessed. Methods: The force generation of ring segments from pulmonary arteries or third-generation airways (obtained from horses subjected to euthanasia for orthopaedic reasons) were studied in an organ bath at 37°C in response to exogenous endothelin and selective endothelin A (BQ123) or B receptor (BQ788) antagonists. Results: ET-1 produced concentration-dependent contractions of the equine pulmonary artery and bronchus. The threshold for contraction was 10-10 and 10-9 mol/l ET-1 for pulmonary artery and bronchus, respectively. The maximal contraction induced by the highest ET-1 concentration (10-7 mol/l) was 173 and 194% of the contraction obtained with 100 mmol/l KCl in pulmonary artery and bronchus, respectively. ET-1 potency was 25 times greater in equine pulmonary artery than in equine bronchus (concentration of ET-1 producing 50% of maximal contraction [EC50] = 5.6 10-9 mol/l and 2.2 10-8 mol/l, respectively). In pulmonary artery, ET-1 induced contractions were significantly inhibited by the ETA receptor antagonist BQ123 (1 μmol/l; dose-response curve to ET-1 was shifted to the right by 5.4-fold), but not by the ETB antagonist BQ788. In bronchus, dose-responses curves to ET-1 were shifted to the right by BQ123 (1 μmol/l; 2.5-fold), but not by BQ788 (1 μmol/l). In the presence of both antagonists, the dose-response curve to ET-1 was shifted to the right by 4.5-fold. Conclusions: These functional studies demonstrate that ET-1 is a potent spasmogen of equine third generation pulmonary artery and bronchus, and that contractions are mediated via ETA receptors in the former and both ETA and ETB receptors in the latter. Potential clinical relevance: Endothelin receptor antagonists may have potential for treating equine pulmonary hypertension or bronchoconstriction. [less ▲]

Spät erst erfahren Sie sich Judith Hermann findet "Nichts als Gespenster"

in Literaturkritik.de (2003)

Spatial aggregation of tropical trees at multiple spatial scales

in Journal of Ecology (2011), 99

1. In tropical forests, species distribution patterns may be strongly context-dependent owing to local stochasticity of recruitment and⁄ or to the specific history and environment of each site. Recent ... [more ▼]

1. In tropical forests, species distribution patterns may be strongly context-dependent owing to local stochasticity of recruitment and⁄ or to the specific history and environment of each site. Recent studies have reported, however, that the degree of spatial aggregation of tropical tree species is partly determined by some species traits irrespectively of site conditions, at least at a very local scale (<200 m). 2. Here, we used standardized large-scale forest inventories of five Central African tropical forests (9670 0.5-ha plots spread over 5550 km2) to quantify the spatial aggregation of 106 tropical tree species at larger spatial scales. For this purpose, we developed a new statistic to quantify the respective contributions of different spatial scales to the aggregation patterns, and we tested whether patterns were consistent across sites. We finally asked whether species characteristics related to dispersal ability, to response to disturbances and to biogeographical range could significantly explain aggregation patterns. 3. Although aggregation patterns varied substantially among sites within each species, they displayed inter-site consistencies (21–24%of the total variance explained by species identity) at the local scale (0.2–1 km) and at the mesoscale (1–10 km) but not at the landscape scale (>10 km). At the two former scales, upper taxonomical levels (family and⁄or order) significantly explained variation in the degree of species aggregation, while at the landscape scale, aggregation was entirely contingent on the site considered. Few species characteristics, except dispersal syndromes and wood density, were able to significantly explain aggregation patterns. 4. Synthesis. One of our most striking results is the high context dependence of species aggregation patterns, whatever the spatial scale considered. However, we showed that species distribution patterns can be predicted, to an extent, at spatial scales much larger than previously investigated in this context. Such patterns may be explained by traits displaying phylogenetic conservatism [less ▲]