7,580 research outputs found

    Mission design for LISA Pathfinder

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    Here we describe the mission design for SMART-2/LISA Pathfinder. The best trade-off between the requirements of a low-disturbance environment and communications distance is found to be a free-insertion Lissajous orbit around the first co-linear Lagrange point of the Sun-Earth system L1, 1.5x 10^6 km from Earth. In order to transfer SMART-2/LISA Pathfinder from a low Earth orbit, where it will be placed by a small launcher, the spacecraft carries out a number of apogee-raise manoeuvres, which ultimatively place it to a parabolic escape trajectory towards L1. The challenges of the design of a small mission are met, fulfilling the very demanding technology demonstration requirements without creating excessive requirements on the launch system or the ground segment.Comment: 7 pages, 6 figures, 5th International LISA Symposium, see http://www.landisoft.de/Markus-Landgra

    Potential of the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor for the monitoring of terrestrial chlorophyll fluorescence

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    Global monitoring of sun-induced chlorophyll fluorescence (SIF) is improving our knowledge about the photosynthetic functioning of terrestrial ecosystems. The feasibility of SIF retrievals from spaceborne atmospheric spectrometers has been demonstrated by a number of studies in the last years. In this work, we investigate the potential of the upcoming TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor satellite mission for SIF retrieval. TROPOMI will sample the 675–775 nm spectral window with a spectral resolution of 0.5 nm and a pixel size of 7 km × 7 km. We use an extensive set of simulated TROPOMI data in order to assess the uncertainty of single SIF retrievals and subsequent spatio-temporal composites. Our results illustrate the enormous improvement in SIF monitoring achievable with TROPOMI with respect to comparable spectrometers currently in-flight, such as the Global Ozone Monitoring Experiment-2 (GOME-2) instrument. We find that TROPOMI can reduce global uncertainties in SIF mapping by more than a factor of 2 with respect to GOME-2, which comes together with an approximately 5-fold improvement in spatial sampling. Finally, we discuss the potential of TROPOMI to map other important vegetation parameters at a global scale with moderate spatial resolution and short revisit time. Those include leaf photosynthetic pigments and proxies for canopy structure, which will complement SIF retrievals for a self-contained description of vegetation condition and functioning

    Prolactin

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    During an oral glucose tolerance test (OGTT) glucose and insulin levels were measured in 26 patients with prolactin-producing pituitary tumours without growth hormone excess. Basal glucose and insulin levels did not differ from the values of an age-matched control group. After glucose load the hyperprolactinaemic patients showed a decrease in glucose tolerance and a hyperinsulinaemia. Bromocriptine (CB 154), which suppressed PRL, improved glucose tolerance and decreased insulin towards normal in a second OGTT. — Human PRL or CB 154 had no significant influence on insulin release due to glucose in the perfused rat pancreas. — These findings suggest a diabetogenic effect of PRL. CB 154 might be a useful drug in improving glucose utilization in hormone-active pituitary tumours

    Leptin Downregulates LPS-Induced Lung Injury: Role of Corticosterone and Insulin

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    Background/Aims: We investigated the effects of leptin in the development of lipopolysaccharide (LPS)-induced acute lung inflammation (ALI) in lean mice. Methods: Mice were administered leptin (1.0 mu g/g) or leptin (1.0 mu g/g) followed by LPS (1.5 mu g/g) intranasally. Additionally, some animals were given LPS (1.5 mu g/g) or saline intranasally alone, as a control. Tissue samples and fluids were collected six hours after instillation. Results: We demonstrated that leptin alone did not induce any injury. Local LPS exposure resulted in significant acute lung inflammation, characterized by a substantial increase in total cells, mainly neutrophils, in bronchoalveolar lavages (BAL). We also observed a significant lymphocyte influx into the lungs associated with enhanced lung expression of chemokines and cytokines (KC, RANTES, TNF-alpha, IFN-beta, GM-CSF and VEGF). LPS-induced ALI was characterized by the enhanced expression of ICAM-1 and iNOS in the lungs. Mice that received LPS showed an increase in insulin levels. Leptin, when administered prior to LPS instillation, abolished all of these effects. LPS induced an increase in corticosterone levels, and leptin potentiated this event. Conclusion: These data suggest that exogenous leptin may promote protection during sepsis, and downregulation of the insulin levels and upregulation of corticosterone may be important mechanisms in the amelioration of LPS-induced ALI.Copyright (c) 2014 S. Karger AG, BaselConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Complex Fluids INCTFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Inst Biomed Sci 1, Dept Pharmacol, Lab Hypertens, BR-1524 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, Dept Immunol, Lab Transplantat Immunobiol, BR-1524 São Paulo, BrazilUniv São Paulo, Lab Inflammat & Vasc Pharmacol, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Lab Clin & Expt Immunobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, Lab Clin & Expt Immunobiol, São Paulo, BrazilFAPESP: 12/51104-8FAPESP: 10/01404-0FAPESP: 12/02270-2FAPESP: 12/10512-6Web of Scienc

    Bound - states for truncated Coulomb potentials

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    The pseudoperturbative shifted - ll expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge
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