1,369 research outputs found

    Lie series for celestial mechanics, accelerators, satellite stabilization and optimization

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    Lie series applications to celestial mechanics, accelerators, satellite orbits, and optimizatio

    The natural organosulfur compound dipropyltetrasulfide prevents HOCL-induced systemic sclerosis in the mouse

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    PublishedArticleIntroduction: The aim of this study was to test the naturally occurring organosulfur compound dipropyltetrasulfide (DPTTS) found in plants, which has antibiotic and anti-cancer properties, as a treatment of HOCl-induced systemic sclerosis in the mouse. Methods: The pro-oxidative, anti-proliferative and cytotoxic effects of DPTTS were evaluated ex vivo on fibroblasts from normal and HOCl-mice. In vivo, the anti-fibrotic and immunomodulating properties of DPTTS were evaluated in the skin and lungs of HOCl-mice. Results: H2O2 production was higher in fibroblasts derived from HOCl-mice than in normal fibroblasts (P<0.05). DPTTS did not increase H2O2 production in normal fibroblasts, but DPTTS dose-dependently increased H2O2 production in HOCl-fibroblasts (P<0.001 with 40μM DPTTS). Because H2O2 reached a lethal threshold in cells from HOCl-mice, the anti-proliferative, cytotoxic and pro-apoptotic effects of DPTTS were significantly higher in HOCl-fibroblasts than for normal fibroblasts. In vivo, DPTTS decreased dermal thickness (P<0.001), collagen content in skin (P<0.01) and lungs (P<0.05), SMA (P<0.01) and pSMAD2/3 (P<0.01) expression in skin, formation of advanced oxidation protein products and anti-DNA topoisomerase-1 antibodies in serum (P<0.05) versus untreated HOCl- mice. Moreover, in HOCl-mice, DPTTS reduced splenic B cell counts (P<0.01), the proliferative rates of B-splenocytes stimulated by lipopolysaccharide (P<0.05) and T-splenocytes stimulated by anti-CD3/CD28 mAb (P<0.001). Ex vivo, it also reduced the production of IL-4 and IL-13 by activated T cells (P<0.05 in both cases). Conclusions: The natural organosulfur compound DPTTS prevents skin and lung fibrosis in the mouse through the selective killing of diseased fibroblasts and its immunomodulating properties. DPTTS may be a potential treatment of Systemic sclerosis.This work was supported by European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement 215009 RedCat for financial support. The authors are grateful to Ms Agnes for her excellent typing of the manuscript

    'Magic coins' and 'magic squares': the discovery of astrological sigils in the Oldenburg Letters

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    Enclosed in a 1673 letter to Henry Oldenburg were two drawings of a series of astrological sigils, coins and amulets from the collection of Strasbourg mathematician Julius Reichelt (1637–1719). As portrayals of particular medieval and early modern sigils are relatively rare, this paper will analyse the role of these medals in medieval and early modern medicine, the logic behind their perceived efficacy, and their significance in early modern astrological and cabalistic practice. I shall also demonstrate their change in status in the late seventeenth century from potent magical healing amulets tied to the mysteries of the heavens to objects kept in a cabinet for curiosos. The evolving perception of the purpose of sigils mirrored changing early modern beliefs in the occult influences of the heavens upon the body and the natural world, as well as the growing interests among virtuosi in collecting, numismatics and antiquities

    Network-Level Connectivity Dynamics of Movie Watching in 6-Year-Old Children

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    Better understanding of the developing brain’s functional mechanisms is critical for improving diagnosis and treatment of different developmental disorders. Particularly, characterizing how the developing brain dynamically reorganizes during different cognitive states may offer novel insight into the neuronal mechanisms of cognitive deficits. Imaging the brain during naturalistic conditions, like movie watching, provides a highly practical way to study young children’s developing functional brain systems. In this study we compared the network-level functional organization of 6-year-old children while they were at rest with their functional connectivity as they watched short video clips. We employed both a data-driven independent component analysis (ICA) approach and a hypothesis-driven seed-based analysis to identify changes in network-level functional interactions during the shift from resting to video watching. Our ICA results showed that naturally watching a movie elicits significant changes in the functional connectivity between the visual system and the dorsal attention network when compared to rest (t(32) = 5.02, p = 0.0001). More interestingly, children showed an immature, but qualitatively adult-like, pattern of reorganization among three of the brain’s higher-order networks (frontal control, default-mode and dorsal attention). For both ICA and seed-based approaches, we observed a decrease in the frontal network’s correlation with the dorsal attention network (ICA: t(32) = −2.46, p = 0.02; Seed-based: t(32) = −1.62, p =0.12) and an increase in its connectivity with the default mode network (ICA: t(32) = 2.84, p = 0.008; Seed-based: t(32) = 2.28, p =0.03), which is highly consistent with the pattern observed in adults. These results offer improved understanding of the developing brain’s dynamic network-level interaction patterns during the transition between different brain states and call for further studies to examine potential alterations to such dynamic patterns in different developmental disorders

    Global Genomic Epidemiology of <i>Salmonella enterica</i> Serovar Typhimurium DT104

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    International audienceIt has been 30 years since the initial emergence and subsequent rapid global spread of multidrug-resistant Salmonella entericaserovar Typhimurium DT104 (MDR DT104). Nonetheless, its origin and transmission route have never been revealed. We used whole-genome sequencing (WGS) and temporally structured sequence analysis within a Bayesian framework to reconstruct temporal and spatial phylogenetic trees and estimate the rates of mutation and divergence times of 315S Typhimurium DT104 isolates sampled from 1969 to 2012 from 21 countries on six continents. DT104 was estimated to have emerged initially as antimicrobial susceptible in ∼1948 (95% credible interval [CI], 1934 to 1962) and later became MDR DT104 in ∼1972 (95% CI, 1972 to 1988) through horizontal transfer of the 13-kb Salmonella genomic island 1 (SGI1) MDR region into susceptible strains already containing SGI1. This was followed by multiple transmission events, initially from central Europe and later between several European countries. An independent transmission to the United States and another to Japan occurred, and from there MDR DT104 was probably transmitted to Taiwan and Canada. An independent acquisition of resistance genes took place in Thailand in ∼1975 (95% CI, 1975 to 1990). In Denmark, WGS analysis provided evidence for transmission of the organism between herds of animals. Interestingly, the demographic history of Danish MDR DT104 provided evidence for the success of the program to eradicate Salmonellafrom pig herds in Denmark from 1996 to 2000. The results from this study refute several hypotheses on the evolution of DT104 and suggest that WGS may be useful in monitoring emerging clones and devising strategies for prevention of Salmonella infections

    Electronic transport in EuB6_6

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    EuB6_6 is a magnetic semiconductor in which defects introduce charge carriers into the conduction band with the Fermi energy varying with temperature and magnetic field. We present experimental and theoretical work on the electronic magnetotransport in single-crystalline EuB6_6. Magnetization, magnetoresistance and Hall effect data were recorded at temperatures between 2 and 300 K and in magnetic fields up to 5.5 T. The negative magnetoresistance is well reproduced by a model in which the spin disorder scattering is reduced by the applied magnetic field. The Hall effect can be separated into an ordinary and an anomalous part. At 20 K the latter accounts for half of the observed Hall voltage, and its importance decreases rapidly with increasing temperature. As for Gd and its compounds, where the rare-earth ion adopts the same Hund's rule ground state as Eu2+^{2+} in EuB6_{6}, the standard antisymmetric scattering mechanisms underestimate the sizesize of this contribution by several orders of magnitude, while reproducing its shapeshape almost perfectly. Well below the bulk ferromagnetic ordering at TCT_C = 12.5 K, a two-band model successfully describes the magnetotransport. Our description is consistent with published de Haas van Alphen, optical reflectivity, angular-resolved photoemission, and soft X-ray emission as well as absorption data, but requires a new interpretation for the gap feature deduced from the latter two experiments.Comment: 35 pages, 12 figures, submitted to PR

    Fine-scale Modeling of Bristlecone Pine Treeline Position in the Great Basin, USA

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    Great Basin bristlecone pine (Pinus longaeva) and foxtail pine (Pinus balfouriana) are valuable paleoclimate resources due to their longevity and climatic sensitivity of their annually-resolved rings. Treeline research has shown that growing season temperatures limit tree growth at and just below the upper treeline. In the Great Basin, the presence of precisely dated remnant wood above modern treeline shows that the treeline ecotone shifts at centennial timescales tracking long-term changes in climate; in some areas during the Holocene climatic optimum treeline was 100 meters higher than at present. Regional treeline position models built exclusively from climate data may identify characteristics specific to Great Basin treelines and inform future physiological studies, providing a measure of climate sensitivity specific to bristlecone and foxtail pine treelines. This study implements a topoclimatic analysis—using topographic variables to explain patterns in surface temperatures across diverse mountainous terrain—to model the treeline position of three semi-arid bristlecone and/or foxtail pine treelines in the Great Basin as a function of growing season length and mean temperature calculated from in situ measurements. Results indicate: (1) the treeline sites used in this study are similar to other treelines globally, and require a growing season length of between 147–153 days and average temperature ranging from 5.5°C–7.2°C, (2) site-specific treeline position models may be improved through topoclimatic analysis and (3) treeline position in the Great Basin is likely out of equilibrium with the current climate, indicating a possible future upslope shift in treeline position
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