985 resultados para Early al-Andalus
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Introduction Xanthine oxidase (XO) is distributed in mammals largely in the liver and small intestine, but also is highly active in milk where it generates hydrogen peroxide (H2O2). Adult human saliva is low in hypoxanthine and xanthine, the substrates of XO, and high in the lactoperoxidase substrate thiocyanate, but saliva of neonates has not been examined. Results Median concentrations of hypoxanthine and xanthine in neonatal saliva (27 and 19 μM respectively) were ten-fold higher than in adult saliva (2.1 and 1.7 μM). Fresh breastmilk contained 27.3±12.2 μM H2O2 but mixing baby saliva with breastmilk additionally generated >40 μM H2O2, sufficient to inhibit growth of the opportunistic pathogens Staphylococcus aureus and Salmonella spp. Oral peroxidase activity in neonatal saliva was variable but low (median 7 U/L, range 2–449) compared to adults (620 U/L, 48–1348), while peroxidase substrate thiocyanate in neonatal saliva was surprisingly high. Baby but not adult saliva also contained nucleosides and nucleobases that encouraged growth of the commensal bacteria Lactobacillus, but inhibited opportunistic pathogens; these nucleosides/bases may also promote growth of immature gut cells. Transition from neonatal to adult saliva pattern occurred during the weaning period. A survey of saliva from domesticated mammals revealed wide variation in nucleoside/base patterns. Discussion and Conclusion During breast-feeding, baby saliva reacts with breastmilk to produce reactive oxygen species, while simultaneously providing growth-promoting nucleotide precursors. Milk thus plays more than a simply nutritional role in mammals, interacting with infant saliva to produce a potent combination of stimulatory and inhibitory metabolites that regulate early oral–and hence gut–microbiota. Consequently, milk-saliva mixing appears to represent unique biochemical synergism which boosts early innate immunity.
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Androgenetic alopecia (AGA) is a highly heritable condition and the most common form of hair loss in humans. Susceptibility loci have been described on the X chromosome and chromosome 20, but these loci explain a minority of its heritable variance. We conducted a large-scale meta-analysis of seven genome-wide association studies for early-onset AGA in 12,806 individuals of European ancestry. While replicating the two AGA loci on the X chromosome and chromosome 20, six novel susceptibility loci reached genome-wide significance (p = 2.62x10(-)(9)-1.01x10(-)(1)(2)). Unexpectedly, we identified a risk allele at 17q21.31 that was recently associated with Parkinson's disease (PD) at a genome-wide significant level. We then tested the association between early-onset AGA and the risk of PD in a cross-sectional analysis of 568 PD cases and 7,664 controls. Early-onset AGA cases had significantly increased odds of subsequent PD (OR = 1.28, 95% confidence interval: 1.06-1.55, p = 8.9x10(-)(3)). Further, the AGA susceptibility alleles at the 17q21.31 locus are on the H1 haplotype, which is under negative selection in Europeans and has been linked to decreased fertility. Combining the risk alleles of six novel and two established susceptibility loci, we created a genotype risk score and tested its association with AGA in an additional sample. Individuals in the highest risk quartile of a genotype score had an approximately six-fold increased risk of early-onset AGA [odds ratio (OR) = 5.78, p = 1.4x10(-)(8)(8)]. Our results highlight unexpected associations between early-onset AGA, Parkinson's disease, and decreased fertility, providing important insights into the pathophysiology of these conditions.
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Objectives Hematoma quality (especially the fibrin matrix) plays an important role in the bone healing process. Here, we investigated the effect of interleukin-1 beta (IL-1β) on fibrin clot formation from platelet-poor plasma (PPP). Methods Five-milliliter of rat whole-blood samples were collected from the hepatic portal vein. All blood samples were firstly standardized via a thrombelastograph (TEG), blood cell count, and the measurement of fibrinogen concentration. PPP was prepared by collecting the top two-fifths of the plasma after centrifugation under 400 × g for 10min at 20°C. The effects of IL-1β cytokines on artificial fibrin clot formation from PPP solutions were determined by scanning electronic microscopy (SEM), confocal microscopy (CM), turbidity, and clot lysis assays. Results The lag time for protofibril formation was markedly shortened in the IL-1β treatment groups (243.8 ± 76.85 in the 50 pg/mL of IL-1β and 97.5 ± 19.36 in the 500 pg/mL of IL-1β) compared to the control group without IL-1β (543.8 ± 205.8). Maximal turbidity was observed in the control group. IL-1β (500 pg/mL) treatment significantly decreased fiber diameters resulting in smaller pore sizes and increased density of the fibrin clot structure formed from PPP (P < 0.05). The clot lysis assay revealed that 500 pg/mL IL-1β induced a lower susceptibility to dissolution due to the formation of thinner and denser fibers. Conclusion IL-1β can significantly influence PPP fibrin clot structure, which may affect the early bone healing process.
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Early studies on grain boundary sliding (GBS) in Mg alloys have suggested frequently that the contribution of GBS to creep is high even under conditions corresponding to dislocation creep. The role of creep strain and grain size in influencing the experimental measurements has not been clearly identified. Grain boundary sliding measurements were conducted in detail over experimental conditions corresponding to diffusion creep as well as dislocation creep in a single-phase Mg-0.7 wt pet Al alloy. The results indicated clearly that the GBS contribution to creep was Very high during,, diffusion creep at low stresses (similar to 75 pct) and substantially reduced during dislocation creep at high stresses (similar to 15 pct). These measurements were consistent with the observation of significant intragranular slip band activity observed in most grains at high stresses and very little slip band activity at low stresses. The experimental measurements and analysis indicated also that the GBS contribution to creep was high during the initial stages of creep and decreased to a steady-state value at large strains.
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Jarvis et al. (Research Articles, 12 December 2014, p. 1320) presented molecular clock analyses that suggested that most modern bird orders diverged just after the mass extinction event at the Cretaceous-Paleogene boundary (about 66 million years ago). We demonstrate that this conclusion results from the use of a single inappropriate maximum bound, which effectively precludes the Cretaceous diversification overwhelmingly supported by previous molecular studies.
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Strain rate sensitivity measurements are used to identify twinning and changes in deformation mechanisms in a Mg AZ31 alloy over a wide range of temperatures and grain sizes. At low temperatures, there is significant twinning at low strains with strain-rate insensitivity; at large strains, strain rate sensitivity is noted, corresponding to deformation by multiple slip. At high temperatures, there is very little twinning and this leads to a significant strain rate sensitivity from the early stages of deformation. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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In this paper, we propose the first approximation for thickness of Quaternary sediment and late Quaternary early Tertiary topography for the part of lower reaches of Narmada valley in a systematic way using the shallow seismic method, that records both horizontal and vertical components of the microtremor (ambient noise) caused by natural processes. The measurements of microtremors were carried out at 31 sites spaced at a grid interval of 5 km s using Lennartz seismometer (5 s period) and City shark-II data acquisition system. The signals recorded were analysed for horizontal to the vertical (H/V) spectral ratio using GEOPSY software. For the present study, we concentrate on frequency range between 0.2 Hz and 10 Hz. The thickness of unconsolidated sediments at various sites is calculated based on non-linear regression equations proposed by Ibs-von Seht and Wohlenberg (1999) and Parolai et al. (2002). The estimated thickness is used to plot digital elevation model and cross profiles correlating with geomorphology and geology of the study area. (C) 2011 Elsevier Ltd. All rights reserved.
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The short-lived radionuclide Ca-41 plays an important role in constraining the immediate astrophysical environment and the formation timescale of the nascent solar system due to its extremely short half-life (0.1 Myr). Nearly 20 years ago, the initial ratio of Ca-41/Ca-40 in the solar system was determined to be (1.41 +/- 0.14) x 10(-8), primarily based on two Ca-Al-rich Inclusions (CAIs) from the CV chondrite Efremovka. With an advanced analytical technique for isotopic measurements, we reanalyzed the potassium isotopic compositions of the two Efremovka CAIs and inferred the initial ratios of Ca-41/Ca-40 to be (2.6 +/- 0.9) x 10(-9) and (1.4 +/- 0.6) x 10(-9) (2 sigma), a factor of 7-10 lower than the previously inferred value. Considering possible thermal processing that led to lower Al-26/Al-27 ratios in the two CAIs, we propose that the true solar system initial value of Ca-41/Ca-40 should have been similar to 4.2 x 10(-9). Synchronicity could have existed between Al-26 and Ca-41, indicating a uniform distribution of the two radionuclides at the time of CAI formation. The new initial Ca-41 abundance is 4-16 times lower than the calculated value for steady-state galactic nucleosynthesis. Therefore, Ca-41 could have originated as part of molecular cloud materials with a free decay time of 0.2-0.4 Myr. Alternative possibilities, such as a last-minute input from a stellar source and early solar system irradiation, could not be definitively ruled out. This underscores the need for more data from diverse CAIs to determine the true astrophysical origin of Ca-41.
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Abstract: During extensive salvage excavations carried out during the years 2004-2008 in a large Early Islamic industrial area at the vicinities of Ramla, in Central Israel, an unparalleled industrial device was unearthed. The star-shaped, soil embedded installation, whose lower part was preserved, consisted of a central pottery jar surrounded by five minor jars, linked by ceramic pipes. Evidence of heat was observed mainly around the central vessel, and metal hollow cones perforated in the tip were found inside the surrounding jars. Although the manufacturing procedures and operation techniques of the installation are not completely clear, it is proposed that the installation is part of an industrial workshop or an alchemy laboratory. Both industry and alchemy were well-developed during the Early Islamic period and very often closely related, to the point that sometimes it is difficult to distinguish between them. The identification proposed is based on comparisons with tools described in literary sources, and somewhat later drawings and etchings. Circumstantial ceramic evidence was found, as well as the proximity of a bathhouse whose guests could have been the consumers of perfumes and unguents seem to reinforce this possibility. Due to the poor state of preservation of the device and the lack of available comparisons, the identification proposed here is tentative, and future research coupled with eventual new discoveries is needed in order to clarify this matter.
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Trade and relations between the southern Levant and other regions of the Near East (mainly Egypt) during the Early Bronze Age (ca. 3,600–2,300 BC) have been the subject of many studies. Research concerning the exchange of local commodities was almost ignored or was discussed in parochial studies, focusing on specific archaeological finds. It is the intention of this paper to present the results of recent research of the exchange of commodities provided by archaeological data from excavations in the Southern Levant with regard to economic theories on the exchange-value of goods and exchange networks. Conclusions regarding the type of society and the forms of government in the Southern Levant during the Early Bronze Age are also presented.
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[ES]En este artículo se pretende dar una visión global, tanto en la exposición de los hechos como en la interpretación de los mismos, del mundo de la brujería (hechicería, adivinación, etc.) y de la superstición (curanderismo, exorcismo, conjuros, bendiciones)en el País Vasco y Navarra durante la Edad Media y primera Edad Moderna.
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[ES] El artículo se centra en el papel jugado por la lengua vasca, el euskara,en el proceso de creación e institucionalización de las colectividades vascas creadas a lo largo del siglo XIX y comienzos del XX en diversos países americanos a los que se dirigieron preferentemente los emigrantes vascos. En todos los casos, las colectividades vascas que se crearon integraban a originarios de todos los territorios tradicionales de Euskal Herria, tanto de las actuales Comunidades autónomas vasca y navarra en España, como del País Vasco-francés. En este proceso el euskara jugó un doble papel,práctico y simbólico, que posibilitó la asunción por parte de los emigrantes vascos,y de la sociedad que los acogió, de una identidad común por encima de otras divisiones basadas en la nacionalidad política o la diversidad ideológica.
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The family Gerreidae contains four genera and 13 species that occur in the western central North Atlantic. Adult gerreids are small to medium size fishes that are abundant in coastal waters, bays, and estuaries in tropical and warm temperate regions and sometimes occur in freshwaters. They are generally associate~ with grassy or open bottoms, but not with reefs. Gerreids are silvery fishes, with deeply forked tails, and extremely protrusible mouth that points downward when protracted. They apparently feed on bottom-dwelling organisms and at least one species (Eucinostomus gula) shows a distinct transition, during the juvenile period, from a planktivore (exclusively copepods) to a carnivore that includes a diet of almost solely polychaetes (Carr & Adams, 1973; Robins and Ray, 1987; Murdy et al., 1997). (PDF contains 10 pages)