380 research outputs found

    Quotient probabilistic normed spaces and completeness results

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    Quotient spaces of probabilistic normed spaces have never been considered. This note is a first attempt to fill this gap: the quotient space of a PN space with respect to one of its subspaces is introduced and its properties are studied. Finally, we investigate the completeness relationship among the PN spaces considered

    Retinal and Renal Microvasculature in Relation to Central Hemodynamics in 11‐Year‐Old Children Born Preterm or At Term

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    Background Prematurity disrupts the perinatal maturation of the microvasculature and macrovasculature and confers high risk of vascular dysfunction later in life. No previous studies have investigated the crosstalk between the microvasculature and macrovasculature in childhood. Methods and Results In a case‐control study, we enrolled 55 children aged 11 years weighing \u3c1000 g at birth and 71 matched controls (October 2014–November 2015). We derived central blood pressure (BP) wave by applanation tonometry and calculated the forward/backward pulse waves by an automated pressure–based wave separation algorithm. We measured the renal resistive index by pulsed wave Doppler and the central retinal arteriolar equivalent by computer‐assisted program software. Compared with controls, patients had higher central systolic BP (101.5 versus 95.2 mm Hg, P\u3c0.001) and backward wave amplitude (15.5 versus 14.2 mm Hg, P=0.029), and smaller central retinal arteriolar equivalent (163.2 versus 175.4 ”m, P\u3c0.001). In multivariable analyses, central retinal arteriolar equivalent was smaller with higher values (+1 SD) of central systolic BP (−2.94 ”m; 95% CI, −5.18 to −0.70 ”m [P=0.011]) and forward (−2.57 ”m; CI, −4.81 to −0.32 ”m [P=0.026]) and backward (−3.20 ”m; CI, −5.47 to −0.94 ”m [P=0.006]) wave amplitudes. Greater renal resistive index was associated with higher backward wave amplitude (0.92 mm Hg, P=0.036). Conclusions In childhood, prematurity compared with term birth is associated with higher central systolic BP and forward/backward wave amplitudes. Higher renal resistive index likely moves reflection points closer to the heart, thereby explaining the inverse association of central retinal arteriolar equivalent with central systolic BP and backward wave amplitude. These observations highlight the crosstalk between the microcirculation and macrocirculation in children. Registration URL: http://www.clinicaltrials.gov. Unique Identifier: NCT02147457

    Frozen magma lenses below the oceanic crust

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    Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 436 (2005): 1149-1152, doi:10.1038/nature03944.The Earth's oceanic crust crystallizes from magmatic systems generated at mid-ocean ridges. Whereas a single magma body residing within the mid-crust is thought to be responsible for the generation of the upper oceanic crust, it remains unclear if the lower crust is formed from the same magma body, or if it mainly crystallizes from magma lenses located at the base of the crust. Thermal modelling, tomography, compliance and wide-angle seismic studies, supported by geological evidence, suggest the presence of gabbroic-melt accumulations within the Moho transition zone in the vicinity of fast- to intermediate-spreading centres. Until now, however, no reflection images have been obtained of such a structure within the Moho transition zone. Here we show images of groups of Moho transition zone reflection events that resulted from the analysis of approximately 1,500 km of multichannel seismic data collected across the intermediate-spreading-rate Juan de Fuca ridge. From our observations we suggest that gabbro lenses and melt accumulations embedded within dunite or residual mantle peridotite are the most probable cause for the observed reflectivity, thus providing support for the hypothesis that the crust is generated from multiple magma bodies

    Organising multi-dimensional biological image information: The BioImage Database

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    Nowadays it is possible to unravel complex information at all levels of cellular organization by obtaining multi-dimensional image information. at the macromolecular level, three-dimensional (3D) electron microscopy, together with other techniques, is able to reach resolutions at the nanometer or subnanometer level. The information is delivered in the form of 3D volumes containing samples of a given function, for example, the electron density distribution within a given macromolecule. The same situation happens at the cellular level with the new forms of light microscopy, particularly confocal microscopy, all of which produce biological 3D volume information. Furthermore, it is possible to record sequences of images over time (videos), as well as sequences of volumes, bringing key information on the dynamics of living biological systems. It is in this context that work on bioimage started two years ago, and that its first version is now presented here. In essence, Bioimage is a database specifically designed to contain multi-dimensional images, perform queries and interactively work with the resulting multi-dimensional information on the World Wide Web, as well as accomplish the required cross-database links. Two sister home pages of bioimage can be accessed at http://www.bioimage.org and http://www-embl.bioimage.or

    Residential greenspace and lung function decline over 20 years in a prospective cohort: the ECRHS study

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    Background The few studies that have examined associations between greenspace and lung function in adulthood have yielded conflicting results and none have examined whether the rate of lung function decline is affected. Objective We explored the association between residential greenspace and change in lung function over 20 years in 5559 adults from 22 centers in 11 countries participating in the population-based, international European Community Respiratory Health Survey. Methods Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were measured by spirometry when participants were approximately 35 (1990–1994), 44 (1999–2003), and 55 (2010–2014) years old. Greenness was assessed as the mean Normalized Difference Vegetation Index (NDVI) in 500 m, 300 m, and 100 m circular buffers around the residential addresses at the time of lung function measurement. Green spaces were defined as the presence of agricultural, natural, or urban green spaces in a circular 300 m buffer. Associations of these greenspace parameters with the rate of lung function change were assessed using adjusted linear mixed effects regression models with random intercepts for subjects nested within centers. Sensitivity analyses considered air pollution exposures. Results A 0.2-increase (average interquartile range) in NDVI in the 500 m buffer was consistently associated with a faster decline in FVC (−1.25 mL/year [95% confidence interval: −2.18 to −0.33]). These associations were especially pronounced in females and those living in areas with low PM10 levels. We found no consistent associations with FEV1 and the FEV1/FVC ratio. Residing near forests or urban green spaces was associated with a faster decline in FEV1, while agricultural land and forests were related to a greater decline in FVC. Conclusions More residential greenspace was not associated with better lung function in middle-aged European adults. Instead, we observed slight but consistent declines in lung function parameters. The potentially detrimental association requires verification in future studies

    Rapport préliminaire sur les activités de la mission archéologique franco-syrienne dans la micro-région d'Al-Rawda (Shamiyeh) : quatriÚme et cinquiÚme campagnes (2005 et 2006)

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    This preliminary report presents the results of two campaigns of excavation and survey in 2005and 2006 on the site of AI-Rawda (West-Central Syria) and in the micro-region of 100 km2 around it. Thesite is a pre-planned circular new town. It was founded around 2400 BCE, in the steppe zone and was inhabitedonly during EB IV, until the end of the 3rd millennium. The work of 2005 and 2006 involved furtherextensive excavation of a sanctuary consisting of two temples and a temenos togeiher with aIl associatedinstallations (including a betyl in situ). The eastem gate of the town was excavated and four lines of defencehave been identified. A stratigraphie sounding in the southwest clarifies the origin of the town. In the necropolisassociated with the site, the excavation of a collective pit burial is presented. Intensive survey wascontinued outside the ancient town, with particular attention to sites that were occupied at the same time asAI-Rawda, to burials, which have been classified by type, and to installations that can be linked to agricultureor pastoralism. This work was supplemented by archaeobotanical, archaeozoological and geo-archaeologicalresearch, as weIl as a study of the environment.Ce rapport prĂ©liminaire prĂ©sente les rĂ©sultats de deux campagnes de fouilles et de prospection conduites en 2005 et 2006 sur le site d’Al-Rawda (Syrie du centre-ouest) et dans la microrĂ©gion de 100 km2 qui l’entoure. Le site, une ville neuve circulaire au plan d’urbanisme prĂ©conçu fondĂ© vers 2500 av. J.-C., se trouve en zone steppique. Il n’est habitĂ© que durant le Bronze ancien IV, jusqu’à la fin du 3e millĂ©naire.Les travaux en 2005 et 2006 ont portĂ© sur la poursuite du dĂ©gagement extensif d’un sanctuaire qui regroupe deux temples et un temenos, avec l’ensemble des installations qu’ils contiennent (dont un bĂ©tyle in situ). À l’est, a Ă©tĂ© mise au jour la porte orientale de la ville tandis que quatre lignes de dĂ©fense ont Ă©tĂ© identifiĂ©es. Un sondage stratigraphique au sud-ouest Ă©claire l’origine de la ville. Dans la nĂ©cropole associĂ©e au site, la fouille d’une tombe en puits collective est prĂ©sentĂ©e.ParallĂšlement, la prospection intensive autour de la ville antique a Ă©tĂ© poursuivie en mettant l’accent sur les sites d’habitat contemporains d’Al-Rawda, les tombes caractĂ©risĂ©es par type et les amĂ©nagements qui peuvent ĂȘtre liĂ©s Ă  une mise en valeur agricole du territoire et au pastoralisme. Ces travaux ont Ă©tĂ© complĂ©tĂ©s par des Ă©tudes archĂ©obotanique, archĂ©ozoologique, gĂ©oarchĂ©ologique et par une Ă©tude des milieux

    Microvascular function is preserved in newly diagnosed rheumatoid arthritis and low systemic inflammatory activity

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    Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality. Microvascular function has been linked to several risk factors for cardiovascular disease and may be affected in RA. It is, however, presently unknown at what point in the disease course the abnormalities in microvascular function occur. We determined whether microvascular function is already disturbed in early disease-modifying antirheumatic drugs (DMARD)-naive RA patients with low systemic inflammation. Fifteen consecutive RA patients with a median symptom duration of 5 months, a C-reactive protein level of ≀20 mg/l and without a history of cardiovascular disease, and age 15 and sex-matched healthy controls were recruited. Endothelium-dependent and endothelium-independent vasodilatation in skin was evaluated with laser Doppler fluxmetry after iontophoresis of acetylcholine and sodium nitroprusside, respectively. Videomicroscopy was used to measure recruitment of skin capillaries after arterial occlusion. CRP and ESR levels were mildly, but significantly elevated in patients compared to controls. No differences in both endothelium-dependent vasodilatation and capillary recruitment were observed between groups [709% (95% CI, 457–961%) vs 797% (95% CI, 556–1,037%), P = 0.59 and 37% (95% CI, 26–47%) vs 41% (95% CI, 31–50%), P = 0.59, respectively]. Skin microvascular function is preserved in early, DMARD-naive RA patients with moderately active RA but low systemic inflammatory activity. Both the extent of the systemic inflammation and disease duration, therefore, may be important determinants of microvascular dysfunction and subsequent increased risk for cardiovascular disease

    Cardiovascular end points and mortality are not closer associated with central than peripheral pulsatile blood pressure components

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    none32Pulsatile blood pressure (BP) confers cardiovascular risk. Whether associations of cardiovascular end points are tighter for central systolic BP (cSBP) than peripheral systolic BP (pSBP) or central pulse pressure (cPP) than peripheral pulse pressure (pPP) is uncertain. Among 5608 participants (54.1% women; mean age, 54.2 years) enrolled in nine studies, median follow-up was 4.1 years. cSBP and cPP, estimated tonometrically from the radial waveform, averaged 123.7 and 42.5 mm Hg, and pSBP and pPP 134.1 and 53.9 mm Hg. The primary composite cardiovascular end point occurred in 255 participants (4.5%). Across fourths of the cPP distribution, rates increased exponentially (4.1, 5.0, 7.3, and 22.0 per 1000 person-years) with comparable estimates for cSBP, pSBP, and pPP. The multivariable-adjusted hazard ratios, expressing the risk per 1-SD increment in BP, were 1.50 (95% CI, 1.33-1.70) for cSBP, 1.36 (95% CI, 1.19-1.54) for cPP, 1.49 (95% CI, 1.33-1.67) for pSBP, and 1.34 (95% CI, 1.19-1.51) for pPP (P<0.001). Further adjustment of cSBP and cPP, respectively, for pSBP and pPP, and vice versa, removed the significance of all hazard ratios. Adding cSBP, cPP, pSBP, pPP to a base model including covariables increased the model fit (P<0.001) with generalized R2 increments ranging from 0.37% to 0.74% but adding a second BP to a model including already one did not. Analyses of the secondary end points, including total mortality (204 deaths), coronary end points (109) and strokes (89), and various sensitivity analyses produced consistent results. In conclusion, associations of the primary and secondary end points with SBP and pulse pressure were not stronger if BP was measured centrally compared with peripherally.noneHuang, Qi-Fang; Aparicio, Lucas S; Thijs, Lutgarde; Wei, Fang-Fei; Melgarejo, Jesus D; Cheng, Yi-Bang; Sheng, Chang-Sheng; Yang, Wen-Yi; Gilis-Malinowska, Natasza; Boggia, JosĂ©; Niiranen, Teemu J; Wojciechowska, Wiktoria; Stolarz-Skrzypek, Katarzyna; Barochiner, Jessica; Ackermann, Daniel; Tikhonoff, ValĂ©rie; Ponte, Belen; Pruijm, Menno; Casiglia, Edoardo; Narkiewicz, Krzysztof; FilipovskĂœ, Jan; Czarnecka, Danuta; Kawecka-Jaszcz, Kalina; Jula, Antti M; Bochud, Murielle; Vanassche, Thomas; Verhamme, Peter; Struijker-Boudier, Harry A J; Wang, Ji-Guang; Zhang, Zhen-Yu; Li, Yan; Staessen, Jan AHuang, Qi-Fang; Aparicio, Lucas S; Thijs, Lutgarde; Wei, Fang-Fei; Melgarejo, Jesus D; Cheng, Yi-Bang; Sheng, Chang-Sheng; Yang, Wen-Yi; Gilis-Malinowska, Natasza; Boggia, JosĂ©; Niiranen, Teemu J; Wojciechowska, Wiktoria; Stolarz-Skrzypek, Katarzyna; Barochiner, Jessica; Ackermann, Daniel; Tikhonoff, ValĂ©rie; Ponte, Belen; Pruijm, Menno; Casiglia, Edoardo; Narkiewicz, Krzysztof; FilipovskĂœ, Jan; Czarnecka, Danuta; Kawecka-Jaszcz, Kalina; Jula, Antti M; Bochud, Murielle; Vanassche, Thomas; Verhamme, Peter; Struijker-Boudier, Harry A J; Wang, Ji-Guang; Zhang, Zhen-Yu; Li, Yan; Staessen, Jan

    Seismic reflection images of a near-axis melt sill within the lower crust at the Juan de Fuca ridge

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    Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 460 (2009): 89-93, doi:10.1038/nature08095.The oceanic crust extends over two thirds of the Earth’s solid surface and is generated along mid-ocean ridges from melts derived from the upwelling mantle. The upper and mid crust are constructed by dyking and seafloor eruptions originating from magma accumulated in mid-crustal lenses at the spreading axis, but the style of accretion of the lower oceanic crust is actively debated. Models based on geological and petrological data from ophiolites propose that the lower oceanic crust is accreted from melt sills intruded at multiple levels between the Moho transition zone (MTZ) and the mid-crustal lens, consistent with geophysical studies that suggest the presence of melt within the lower crust. However, seismic images of molten sills within the lower crust have been elusive. To date only seismic reflections from mid-crustal melt lenses and sills within the MTZ have been described, suggesting that melt is efficiently transported through the lower crust. Here we report deep crustal seismic reflections off the southern Juan de Fuca Ridge that we interpret as originating from a molten sill presently accreting the lower oceanic crust. The sill sits 5-6 km beneath the seafloor and 850-900 m above the MTZ, and it is located 1.4-3.2 km off thespreading axis. Our results provide evidence for the existence of low permeability barriers to melt migration within the lower section of modern oceanic crust forming at intermediate-to-fast spreading rates, as inferred from ophiolite studies.This research was supported by grants form the US NSF
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