Télédétection et caractéristiques physiques des dépôts meubles dans un milieu anciennement englacé du sud du Québec

L'analyse géomorphologique à partir de bandes spectrales débordant le rayonnement visible est encore au stade expérimental. La stratigraphie et la structure interne des dépôts meubles ne peuvent être directement détectées, mais la granulométrie et les formes de surface peuvent l'être. Dans le cas des surfaces dénudées, la granulométrie est reliée à la réflectance dans le visible et le proche infrarouge et à la rugosité détectable par le radar. Dans le cas des surfaces recouvertes de végétation, la granulométrie peut être déduite indirectement des conditions d'humidité des sols, qui commandent l'alimentation en eau des plantes, dans le visible, le proche infrarouge, l'infrarouge thermique, le radar (constante diélectrique) et théoriquement les micro-ondes passives. Sans compter la traditionnelle photointerprétation stéréoscopique, les formes de surface peuvent être reconnues soit de façon automatisée, surtout dans le cas des formes linéaires, lorsque l'on possède des documents numérisés, soit de façon visuelle par rehaussement d'image lors de la prise de vue (radar, thermographies). Les formes de surface peuvent aussi être rehaussées au moment du traitement par incorporation d'un modèle numérique de terrain ou avec des images de composantes spectrales. Des expériences ont été conduites en Estrie afin de distinguer les tills des dépôts fluvioglaciaires ou glacio-lacustres. Il en résulte que l'imagerie la plus efficace dans le cas d'une analyse visuelle est l'infrarouge thermique diurne en automne quand les effets de l'insolation sur la topographie sont maximaux et où ceux des écarts d'albédo sont réduits.Géomorphologie analysis based on or using spectral bands beyond the visible is still at an experimental stage. If stratigraphy and internal structure of surficial deposits cannot be directly detected, grain size and surface landforms are detectable, however. In the case of non vegetated areas, grain size is related to visible and near infrared reflectance, and to surface roughness detectable by airborne radar. In the case of vegetated surfaces, grain size can be inferred indirectly from soil moisture conditions which are detectable in the visible, near infrared, thermal infrared, radar (dielectric constant) and theoretically in the passive microwave spectral ranges. Besides traditional stereoscopic photointerpretation, surface landforms, especially linear ones, can be recognized either automatically, if digital data are available, or visually through enhancements generated in numerical analysis by data acquisition methods (radar, thermography). Surface landforms can also be enhanced by incorporation of a digital terrain model or by principal component enhancement. Experiments have been conducted in the Eastern Townships of Québec, in order to distinguish glacial tills from fluvioglacial or lacustrine deposits. The most efficient imagery for this purpose, using visual analysis, is daytime thermal infrared, acquired during the Fall, when insolation effects on topography are greatest and albedo variations are least.Geomorphologische Analyse die sich auf den Gebrauch, von ausserhalb des Sichtbaren liegenden spectralen Streifen grùndet, ist noch im Experimentalstadium. Wenn auch Stratigraphie und innere Struktur der Oberflàchen Ablagerungen nicht direkt untersucht werden kônnen, sind jedoch Korngrôsse und Oberflàchen Landformen untersuchbar. Im FaIIe von nicht Vegetations gedeckten Gegenden, ist die Korngrôsse verbunden mit der sichtbaren und nahinfraroten Reflektanz und mit der Oberflàchen Rauheit, welche mit dem Radar detektiert werden kann. Im FaIIe von Vegetations bedeckten Gegenden kann die Korngrôsse durch die Bodenfeuchtigkeits Verhâltnisse, welche durch die sichtbaren, nahinfraroten, thermal infraroten, Radar (dielektrische Konstante) und theoretisch in dem passiven Mikrowellen spektral Raum, angenommen werden kônnen. Neben der traditionellen stereoskopischen Photo-interpretation, Oberflachenlandformen, besonders lineâre, kônnen entweder automatisch erkannt werden, wenn digital Daten vorhanden sind, oder visuele, durch das Erheben des Bildes bei der Aufnahme (Radar, Thermographie). Die Oberflàchenformen kônnen auch verbessert werden durch das Einschliessen von digitalen Terrain-Modellen oder durch Hauptkomponenten Verbesserung. In den Cantons de l'Est in Québec, wurden Expérimente durchgefùhrt, urn glazialen Till von fluvioglazialen oder lakustrinen Ablagerungen zu unterscheiden. Es ergiebt sich, dass die leistungsfàhigsten Abbildungen fur eine visuelle Analyse vom thermischen, Tagesinfrarot stammen im Herbst, wenn die Einflusse der Sonnenbestrahlung auf die Topographie am grôssten sind, und die der albedo Abweichungen reduziert sind

Hydrodynamical simulations of galaxy formation with non-Gaussian initial conditions

Collisionless simulations of structure formation with significant local primordial non-Gaussianities at Mpc scales have shown that a non-Gaussian tail favouring underdensities, with a negative $f_{\rm NL}$ parameter, can significantly change the merging history of galaxy-sized dark matter halos, which then typically assemble later than in vanilla $\Lambda$CDM. Moreover, such a small-scale negative $f_{\rm NL}$ could have interesting consequences for the cosmological $S_8$ tension. Here, we complement our previous work on collisionless simulations with new hydrodynamical simulations of galaxy formation in boxes of 30 Mpc/$h$, using the {\sc RAMSES} code. In particular, we show that all feedback prescriptions being otherwise identical, simulations with a negative $f_{\rm NL} \sim -1000$ on small scales, hence forming galaxies a bit later than in vanilla $\Lambda$CDM, allow to form simulated galaxies with more disky kinematics than in the vanilla case. Therefore, such small-scale primordial non-Gaussianities could potentially help alleviate, simultaneously, tensions in cosmology and galaxy formation. These hydrodynamical simulations on small scales will need to be complemented with larger box simulations with scale-dependent non-Gaussianities, to statistically confirm these trends and explore their observational consequences in further detail.Comment: 14 pages, 8 figures, comments welcome :

Expanding the light absorption of poly(3-hexylthiophene) by end-functionalization with π-extended porphyrins.

Poly(3-hexylthiophene)s end-functionalized with π-extended porphyrins have been synthesized in a one-pot procedure. The polymers show a broad absorption profile extending to 700 nm and a fibrillar microstructure, which can be tuned through judicious selection of the porphyrin molar ratio

Romiplostim for temozolomide-induced thrombocytopenia in glioblastoma: The PLATUM trial

OBJECTIVE To determine the efficacy of the thrombopoietin receptor agonist romiplostim for the prevention of temozolomide-induced thrombocytopenia in newly diagnosed glioblastoma. METHODS In the PLATUM phase II open-label, multicenter, single-arm trial, patients diagnosed with Common Terminology Criteria for Adverse Events grade 3 or 4 thrombocytopenia during chemoradiotherapy received weekly subcutaneous romiplostim injections. PLATUM aimed at demonstrating that the percentage of thrombocytopenic patients treated with romiplostim able to complete 6 cycles of maintenance temozolomide chemotherapy exceeded 10% (0 = 0.10; A = 0.35). Using type I error equal to 0.05% and 95% power, 31 patients had to be recruited. According to a Fleming 2-step design with a preplanned interim analysis after recruitment of 20 patients (step 1), the trial was terminated early for success. RESULTS Twenty patients were enrolled in step 1. Median age was 61 years (range 33-73). Twelve patients received 6 temozolomide cycles, corresponding to a success rate of 60% (95% confidence interval 36%-81%). Four patients discontinued temozolomide because they did not respond to romiplostim, 2 for progression, and 2 for adverse events unrelated to romiplostim. CONCLUSION The thrombopoietin receptor agonist romiplostim improves exposure to chemotherapy in patients with glioblastoma experiencing temozolomide-induced thrombocytopenia. CLINICALTRIALSGOV IDENTIFIER NCT02227576. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence that for patients with glioblastoma and thrombocytopenia, romiplostim is effective for the secondary prophylaxis of temozolomide-induced thrombocytopenia

Phosphonium-based polythiophene conjugated polyelectrolytes with different surfactant counterions: thermal properties, self-assembly and photovoltaic performances

© 2020 Society of Industrial Chemistry Phosphonium-based polythiophene conjugated polyelectrolytes (CPEs) with three different counterions (dodecylsulfate, octylsulfate and perfluorooctane sulfonate) are synthesized to determine how the nature of the counterion affects the thermal properties, the self-assembly in thin films and the performance as the cathode interfacial layer in polymer solar cells (PSCs). The counterion has a significant effect on the thermal properties of the CPEs, affecting both their glass transition and crystalline behaviour. Grazing-incidence wide-angle X-ray scattering studies also indicate that changing the nature of the counterion influences the microstructural organization in thin films (face-on versus edge-on orientation). The affinity of the CPEs with the underlying photoactive layer in PSCs is highly correlated with the counterion species. Finally, in addition to an increase of the power conversion efficiency of ca 15% when using these CPEs as cathode interfacial layers in PSCs, a higher device stability is noted, compared to a reference device with a calcium interlayer. © 2020 Society of Industrial Chemistry

Self-assembled conjugated polyelectrolyte-surfactant complexes as efficient cathode interlayer materials for bulk heterojunction organic solar cells

Conjugated polyelectrolyte–surfactant cathodic interface layers lead to improved power conversion efficiencies in organic solar cells.</p

All-conjugated cationic copolythiophene "rod-rod" block copolyelectrolytes: Synthesis, optical properties and solvent-dependent assembly

The optical and thermal properties and solvent-dependent assembly of all-conjugated cationic copolythiophene block copolyelectrolytes are investigated.</p

A phosphorylation-and-ubiquitylation circuitry driving ATR activation and homologous recombination

Abstract RPA-coated single-stranded DNA (RPA–ssDNA), a nucleoprotein structure induced by DNA damage, promotes ATR activation and homologous recombination (HR). RPA is hyper-phosphorylated and ubiquitylated after DNA damage. The ubiquitylation of RPA by PRP19 and RFWD3 facilitates ATR activation and HR, but how it is stimulated by DNA damage is still unclear. Here, we show that RFWD3 binds RPA constitutively, whereas PRP19 recognizes RPA after DNA damage. The recruitment of PRP19 by RPA depends on PIKK-mediated RPA phosphorylation and a positively charged pocket in PRP19. An RPA32 mutant lacking phosphorylation sites fails to recruit PRP19 and support RPA ubiquitylation. PRP19 mutants unable to bind RPA or lacking ubiquitin ligase activity also fail to support RPA ubiquitylation and HR. These results suggest that RPA phosphorylation enhances the recruitment of PRP19 to RPA–ssDNA and stimulates RPA ubiquitylation through a process requiring both PRP19 and RFWD3, thereby triggering a phosphorylation-ubiquitylation circuitry that promotes ATR activation and HR

Triterpenoid saponins from the stem bark of pentaclethra eetveldeana

Two previously undescribed triterpenoid saponins together with 4 known ones were isolated from the stem bark of Pentaclethra eetveldeana De Wild. & Th. Dur. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments in combination with mass spectrometry as 3- O-β- d -glucopyranosyl- (1→2)- [β- d -glucopyranosyl- (1→3)]-β- d -glucopyranosyl- (1→4)- β- d -glucopyranosyl- (1→3)-α- l -rhamnopyranosyl- (1→2)-[β- d-glucopyranosyl- (1→4)]-α- l -arabinopyranosyloleanolic acid and 3- O -β- d -glucopyranosyl- (1→2)-[β- d -glucopyranosyl- (1→3)]-β- d -glucopyranosyl- (1→4)-β- d -glucopyranosyl- (1→3)- α -l -rhamnopyranosyl- (1→2)-[β- d -glucopyranosyl- (1→4)]-α- l -arabinopyranosylhederagenin. © The Author(s) 2019

Triterpenoid saponins from the root bark of haplocoelum congolanum

peer reviewedTwo undescribed triterpenoid saponins together with 5 known ones were isolated from the root bark of Haplocoelum congolanum Hauman. Their structures were elucidated by spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance experiments in combination with mass spectrometry as 3-O-(4-O-[3-hydroxy-3-methylglutaryl])-α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid and 3-O-α-l-arabinofuranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid. © The Author(s) 201