193 research outputs found
Planetary Science Virtual Observatory architecture
In the framework of the Europlanet-RI program, a prototype of Virtual
Observatory dedicated to Planetary Science was defined. Most of the activity
was dedicated to the elaboration of standards to retrieve and visualize data in
this field, and to provide light procedures to teams who wish to contribute
with on-line data services. The architecture of this VO system and selected
solutions are presented here, together with existing demonstrators
RĂ©partition de la chevĂȘche d'athĂ©na (athene noctua scop.) et variation d'Ă©chelle d'analyse des paysages
Une typologie paysagĂšre Ă©tablie Ă partir de pixels Ă©lĂ©mentaires de 250 m de cĂŽtĂ© dans trois zones en France (Vosges du Nord, Scarpe-Escaut et Causse MĂ©jean) a permis de dĂ©terminer 5 Ă 8 types primaires, permettant d'expliquer la rĂ©partition des ChevĂȘches d'AthĂ©na (Athene noctua). Les milieux favorables sont anthropisĂ©s, avec des modes d'occupation du sol conduits sur de petites surfaces. Une typologie secondaire rĂ©alisĂ©e pour diffĂ©rentes Ă©chelles d'analyse par agglomĂ©ration de pixels Ă©lĂ©mentaires rĂ©vĂšle une certaine diversitĂ© incluant des Ă©lĂ©ments paysagers favorables. Ainsi les fenĂȘtres obtenues par agglomĂ©ration de pixels Ă©lĂ©mentaires adjacents les plus favorables ne sont pas uniquement formĂ©es de pixels favorables aux chouettes. Cette typologie secondaire a permis de dĂ©terminer une Ă©chelle d'analyse de l'habitat expliquant la rĂ©partition de l'espĂšce et qui varie de 56 Ă 156 ha selon les zones d'Ă©tude.Distribution of the Little Owl (Athene noctua) is accounted for by reference to primary landscape types identified from a grid of 250 m x 250 m cells in three areas of France (Northem Vosges, Scarpe-Escaut Plain, and Causse MĂ©jean) . Preferred environments are those affected by human activity where small areas are given over to different land uses. Secondary landscape types constructed for different scales by aggregating cells of primary landscape types of analysis reveal a very heterogeneous landscape mosaic. Windows formed by aggregating the most suitable adjacent cells are not exclusively composed of cells preferred by owls. These secondary landscape types provide a habitat scale of analysis explaining species distribution and ranging from 56 to 156 hectares depending on the study regions
Recommended from our members
Do magnetospheric shear Alfvén waves generate sufficient electron energy flux to power the aurora?
Using a self-consistent drift-kinetic simulation code, we investigate whether electron acceleration owing to shear AlfvĂ©n waves in the plasma sheet boundary layer is sufficient to cause auroral brightening in the ionosphere. The free parameters used in the simulation code are guided by in situ observations of wave and plasma parameters in the magnetosphere at distances >4 RE from the Earth. For the perpendicular wavelength used in the study, which maps to âŒ4 km at 110 km altitude, there is a clear amplitude threshold which determines whether magnetospheric shear AlfvĂ©n waves above the classical auroral acceleration region can excite sufficient electrons to create the aurora. Previous studies reported wave amplitudes that easily exceed this threshold; hence, the results reported in this paper demonstrate that auroral acceleration owing to shear AlfvĂ©n waves can occur in the magnetosphere at distances >4 RE from the Earth
Vortex nozzle interaction in solid rocket motors: A scaling law for upstream acoustic response
In solid rocket motors, vortex nozzle interactions can be a source of large-amplitude pressure pulsations. Using a two-dimensional frictionless flow model, a scaling law is deduced, which describes the magnitude of a pressure pulsation as being proportional to the product of the dynamic pressure of the upstream main flow and of vortex circu- lation. The scaling law was found to be valid for both an integrated noz- zle with surrounding cavity and a nozzle geometry without surrounding cavity that forms a right angle with the combustion chamber side wall. Deviations from the scaling law only occur when unrealistically strong circulations are considered
EMC ASPECTS OF TURBULENCE HEATING OBSERVER (THOR) SPACECRAFT
Turbulence Heating ObserveR (THOR) is a spacecraft mission dedicated to the study of plasma turbulence in near-Earth space. The mission is currently under study for implementation as a part of ESA Cosmic Vision program. THOR will involve a single spinning spacecraft equipped with state of the art instruments capable of sensitive measurements of electromagnetic fields and plasma particles. The sensitive electric and magnetic field measurements require that the spacecraft-generated emissions are restricted and strictly controlled; therefore a comprehensive EMC program has been put in place already during the study phase. The THOR study team and a dedicated EMC working group are formulating the mission EMC requirements state of its EMC requirements
Ras Inhibition Induces Insulin Sensitivity and Glucose Uptake
BACKGROUND: Reduced glucose uptake due to insulin resistance is a pivotal mechanism in the pathogenesis of type 2 diabetes. It is also associated with increased inflammation. Ras inhibition downregulates inflammation in various experimental models. The aim of this study was to examine the effect of Ras inhibition on insulin sensitivity and glucose uptake, as well as its influence on type 2 diabetes development. METHODS AND FINDINGS: The effect of Ras inhibition on glucose uptake was examined both in vitro and in vivo. Ras was inhibited in cells transfected with a dominant-negative form of Ras or by 5-fluoro-farnesylthiosalicylic acid (F-FTS), a small-molecule Ras inhibitor. The involvement of IÎșB and NF-ÎșB in Ras-inhibited glucose uptake was investigated by immunoblotting. High fat (HF)-induced diabetic mice were treated with F-FTS to test the effect of Ras inhibition on induction of hyperglycemia. Each of the Ras-inhibitory modes resulted in increased glucose uptake, whether in insulin-resistant C2C12 myotubes in vitro or in HF-induced diabetic mice in vivo. Ras inhibition also caused increased IÎșB expression accompanied by decreased expression of NF-ÎșB . In fat-induced diabetic mice treated daily with F-FTS, both the incidence of hyperglycemia and the levels of serum insulin were significantly decreased. CONCLUSIONS: Inhibition of Ras apparently induces a state of heightened insulin sensitization both in vitro and in vivo. Ras inhibition should therefore be considered as an approach worth testing for the treatment of type 2 diabetes
BepiColomboâs Cruise Phase: Unique Opportunity for Synergistic Observations
The investigation of multi-spacecraft coordinated observations during the cruise phase of BepiColombo (ESA/JAXA) are reported, with a particular emphasis on the recently launched missions, Solar Orbiter (ESA/NASA) and Parker Solar Probe (NASA). Despite some payload constraints, many instruments onboard BepiColombo are operating during its cruise phase simultaneously covering a wide range of heliocentric distances (0.28 AUâ0.5 AU). Hence, the various spacecraft configurations and the combined in-situ and remote sensing measurements from the different spacecraft, offer unique opportunities for BepiColombo to be part of these unprecedented multipoint synergistic observations and for potential scientific studies in the inner heliosphere, even before its orbit insertion around Mercury in December 2025. The main goal of this report is to present the coordinated observation opportunities during the cruise phase of BepiColombo (excluding the planetary flybys). We summarize the identified science topics, the operational instruments, the method we have used to identify the windows of opportunity and discuss the planning of joint observations in the future
Excitonic AND Logic Gates on DNA Brick Nanobreadboards
A promising application of DNA self-assembly is the fabrication of chromophore-based excitonic devices. DNA brick assembly is a compelling method for creating programmable nanobreadboards on which chromophores may be rapidly and easily repositioned to prototype new excitonic devices, optimize device operation, and induce reversible switching. Using DNA nanobreadboards, we have demonstrated each of these functions through the construction and operation of two different excitonic AND logic gates. The modularity and high chromophore density achievable via this brick-based approach provide a viable path toward developing information processing and storage systems
First-line therapy with gemcitabine and paclitaxel in locally, recurrent or metastatic breast cancer: A phase II study
BACKGROUND: This phase II study evaluated the efficacy and safety of gemcitabine (G) plus paclitaxel (T) as first-line therapy in recurrent or metastatic breast cancer. METHODS: Patients with locally, recurrent or metastatic breast cancer and no prior chemotherapy for metastatic disease received G 1200 mg/m(2 )on days 1 and 8, and T 175 mg/m(2 )on day 1 (before G) every 21 days for a maximum of 10 cycles. RESULTS: Forty patients, 39 metastatic breast cancer and 1 locally-advanced disease, were enrolled. Their median age was 61.5 years, and 85% had a World Health Organization performance status (PS) of 0 or 1. Poor prognostic factors at baseline included visceral involvement (87.5%) and â„2 metastatic sites (70%). Also, 27 (67.5%) patients had prior adjuvant chemotherapy, 25 of which had prior anthracyclines. A total of 220 cycles (median 6; range, 1â10) were administered. Of the 40 enrolled patients, 2 had complete response and 12 partial response, for an overall response rate of 35.0% for intent-to-treat population. Among 35 patients evaluable for efficacy the response rate was 40%. Additional 14 patients had stable disease, and 7 had progressive disease. The median duration of response was 12 months; median time to progression, 7.2 months; median survival, 25.7 months. Common grade 3/4 toxicities were neutropenia in 17 (42.5%) patients each, grade 3 leukopenia in 19 (47.5%), and grade 3 alopecia in 30 (75.0%) patients; 1 (2.5%) patient had grade 4 thrombocytopenia. CONCLUSION: GT exhibited encouraging activity and tolerable toxicity as first-line therapy in metastatic breast cancer. Phase III trials for further evaluation are ongoing
- âŠ