106,500 research outputs found
Observations magnétiques sur 509 lieux faites en Asie et en Europe pendant la période de 1867-1894
No full textpar Dr. H. Fritsche (Directeur émérite de l'Observatoire I. Russe de Pékin)handschriftlich vervielfältig
Unit labor cost growth differentials in the Euro area, Germany, and the US: lessons from PANIC and cluster analysis
No full textInflation differentials in the Euro area are mainly due to a sustained divergence of wage developments across the Euro area, and narrower differences in labour productivity growth (Alvarez et al., 2006). We investigate convergence of inflation using unit labour cost (ULC) growth and applying PANIC (Bai and Ng, 2002, 2004) and cluster procedures (Hobijn and Franses, 2000, Busetti et al., 2006) to Euro area countries as well as US States, US Census Regions and German Laender. Euro area differs in that dispersion in general (and its fraction due to idiosyncratic factors in specific) is larger and common factors are much less important in explaining the variance of ULC growth. We report evidence for convergence clusters in all countries.Unit labor costs, inflation, European Monetary Union, Germany, United States of America, convergence, convergence clubs, panel unit root tests, PANIC
Correction to: female reproductive organs of Brassica napus are more sensitive than male to transient heat stress
No full textThe article Female reproductive organs of Brassica napus are more sensitive than male to transient heat stress, written by Sheng Chen, Renu Saradadevi, Miriam S. Vidotti, Roberto Fritsche-Neto, Jose Crossa, Kadambot H. M. Siddique, Wallace A. Cowling, was originally published Online First without Open Access. After publication in volume 217: 117 the author decided to opt for Open Choice and to make the article an Open Access publication. Therefore, the copyright of the article has been changed t
Long-term effects of selected xenobiotica on freshwater green-algae - development of a flow-through test system
No full textSchäfer H, Wenzel A, Fritsche U, Röderer G, Traunspurger W. Long-term effects of selected xenobiotica on freshwater green-algae - development of a flow-through test system. The Science of the Total Environment, Suppl., Part 1. 1993;(Suppl., Part 1):735-740
Changes of the plasma metabolome during an oral glucose tolerance test: is there more than glucose to look at?
No full textZhao X, Peter A, Fritsche J, Elcnerova M, Fritsche A, Haring HU, Schleicher ED, Xu G, Lehmann R. Changes of the plasma metabolome during an oral glucose tolerance test: is there more than glucose to look at? Am J Physiol Endocrinol Metab 296: E384-E393, 2009. First published December 9, 2008; doi: 10.1152/ajpendo.90748.2008.-The oral glucose tolerance test (oGTT) is a common tool to provoke a metabolic challenge for scientific purposes, as well as for diagnostic reasons, to monitor the kinetics of glucose and insulin. Here, we aimed to follow the variety of physiological changes of the whole metabolic pattern in plasma during an oGTT in healthy subjects in a nontargeted reversed-phase ultra performance liquid chromatography coupled to electrospray ionization quadrupole time of flight mass spectrometric metabolomics approach. We detected 11,500 metabolite ion masses/individual. Applying multivariate data analysis, four major groups of metabolites have been detected as the most discriminating oGTT biomarkers: free fatty acids (FFA), acylcarnitines, bile acids, and lysophosphatidylcholines. We found in detail 1) a strong decrease of all saturated and monounsaturated FFA studied during the oGTT; 2) a significant faster decline of palmitoleate (C16:1) and oleate (C18:1) FFA levels than their saturated counterparts; 3) a strong relative increase of polyunsaturated fatty acids in the fatty acid pattern at 120 min; and 4) a clear decrease in plasma C10:0, C12:0, and C14:1 acylcarnitine levels. These data reflect the switch from beta-oxidation to glycolysis and fat storage during the oGTT. Moreover, the bile acids glycocholic acid, glycochenodeoxycholic acid, and glycodeoxycholic acid were highly discriminative, showing a biphasic kinetic with a maximum of a 4.5- to 6- fold increase at 30 min after glucose ingestion, a significant decrease over the next 60 min followed by an increase until the end of the oGTT. Lysophosphatidylcholines were also increased significantly. The findings of our metabolomics study reveal detailed insights in the complex physiological regulation of the metabolism during an oGTT offering novel perspectives of this widely used procedure
Improved modelling of surface forces in the orbit determination of ERS and ENVISAT
No full textPrecise orbit determination of the European remote sensing satellites ERS-2 and ENVISAT, a prerequisite for the processing of their altimeter data, requires highly accurate force models. Inaccuracies in the modelling of non-gravitational forces, caused by interaction of photons, molecules, and atoms with the spacecraft surfaces, form a major error source. A highly detailed new non-gravitational force modelling package named ANGARA was implemented and tested for ERS-2 and ENVISAT. The resulting orbits for ERS-2 were compared with those from an existing box-wing panel model and a simple constant-area model. In addition, the effects on orbit accuracy of three thermospheric density models (DTM94, MSIS-86, and NRLMSISE-00) and a horizontal wind model (HWM-93) were evaluated. Force model parameters, estimated from tracking data during the precise orbit determination process, absorb most of the differences between the considered models. At the same time, an analysis of these parameters, and orbit determination runs with a limited parameterization, can give important clues about modelling accuracy. Atmospheric density is the dominant error source at high solar activity, degrading the radial orbit accuracy. Radiation pressure forces, for which uncertainties in material properties are the largest error source, play an equally important role at low solar activity
Improved modelling of surface forces in the orbit determination of ERS and ENVISAT
No full textPrecise orbit determination of the European remote sensing satellites ERS-2 and ENVISAT, a prerequisite for the processing of their altimeter data, requires highly accurate force models. Inaccuracies in the modelling of non-gravitational forces, caused by interaction of photons, molecules, and atoms with the spacecraft surfaces, form a major error source. A highly detailed new non-gravitational force modelling package named ANGARA was implemented and tested for ERS-2 and ENVISAT. The resulting orbits for ERS-2 were compared with those from an existing box-wing panel model and a simple constant-area model. In addition, the effects on orbit accuracy of three thermospheric density models (DTM94, MSIS-86, and NRLMSISE-00) and a horizontal wind model (HWM-93) were evaluated. Force model parameters, estimated from tracking data during the precise orbit determination process, absorb most of the differences between the considered models. At the same time, an analysis of these parameters, and orbit determination runs with a limited parameterization, can give important clues about modelling accuracy. Atmospheric density is the dominant error source at high solar activity, degrading the radial orbit accuracy. Radiation pressure forces, for which uncertainties in material properties are the largest error source, play an equally important role at low solar activity
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Slc11a1 limits intracellular growth of Salmonella enterica sv. Typhimurium by promoting macrophage immune effector functions and impairing bacterial iron acquisition
No full textThe natural resistance-associated macrophage protein 1, Slc11a1, is a phagolysosomal transporter for protons and divalent ions including iron that confers host protection against diverse intracellular pathogens including Salmonella. We investigated and compared the regulation of iron homeostasis and immune function in RAW264.7 murine phagocytes stably transfected with non-functional Slc11a1 and functional Slc11a1 controls in response to an infection with Salmonella enterica serovar Typhimurium. We report that macrophages lacking functional Slc11a1 displayed an increased expression of transferrin receptor 1, resulting in enhanced acquisition of transferrin-bound iron. In contrast, cellular iron release mediated via ferroportin 1 was significantly lower in Salmonella-infected Slc11a1-negative macrophages in comparison with phagocytes bearing Slc11a1. Lack of Slc11a1 led to intracellular persistence of S.?enterica serovar Typhimurium within macrophages, which was paralleled by a reduced formation of nitric oxide, tumour necrosis factor-alpha and interleukin-6 in Slc11a1-negative macrophages following Salmonella infection, whereas interleukin-10 production was increased. Moreover, Slc11a1-negative phagocytes exhibited higher cellular iron content, resulting in increased iron acquisition by intracellular Salmonella. Our observations indicate a bifunctional role for Slc11a1 within phagocytes. Slc11a restricts iron availability, which first augments pro-inflammatory macrophage effector functions and second concomitantly limits microbial iron access. <br/
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
