Isotopic anomalies have been found for Ba and Nd in two inclusions from the Allende meteorite. These inclusions are typical Ca-Al-rich objects associated with early condensates from the solar nebula but have distinctive O and Mg isotopic anomalies of the FUN type. Sample Cl shows a depletion only in Ba of 2 parts in 10 and normal Nd. Sample EK1-4-1 shows large positive excesses in the unshielde...

[1] When subjected to lower-mantle pressures and temperatures, natural ‘‘anhydrous’’ basalt containing 0.2 wt.% H2O forms a phase assemblage in which SiO2 stishovite is a significant carrier of hydrogen (up to 500 ppm H2O by weight, as hydroxide), whereas the coexisting (Mg, Fe, Al, Ca)SiO3 perovskite appears to be not (upper bound of 50 ppm (wt) H2O). Contrary to the devolatilization character...

BACKGROUND Common autoimmune disorders tend to coexist in the same subjects and to cluster in families. METHODS We performed a cross-sectional multicenter study of 3286 Caucasian subjects (2791 with Graves' disease; 495 with Hashimoto's thyroiditis) attending UK hospital thyroid clinics to quantify the prevalence of coexisting autoimmune disorders. All subjects completed a structured question...

AIM To describe the classification of aneurysms coexisting with arteriovenous malformations (AVMs) and their endovascular treatment. MATERIAL AND METHODS Based on the basis of radiological findings and clinical features, 59 aneurysms coexisting with AVMs were classified into four different types: intranidal, flow-related (proximal and distal), and unrelated. These aneurysms were treated by en...

We studied the interfacial tension between coexisting phases of aqueous solutions of dextran and polyethylene glycol. First, we characterized the phase diagram of the system and located the binodal. Second, the tie lines between the coexisting phases were determined using a method that only requires measuring the density of the coexisting phases. The interfacial tension was then measured by a s...

The structure and composition of coexisting bilayer phases separated in binary mixtures of dipalmitoylphosphatidylcholine and cholesterol and ternary mixtures of equimolar proportions of dipalmitoyl- and dioleoylphosphatidycholines containing different proportions of cholesterol have been characterized by synchrotron X-ray diffraction methods. The liquid-ordered phase is distinguished from gel ...

Cristobalite is a common mineral in volcanic ash produced from dome-forming eruptions. Assessment of the respiratory hazard posed by volcanic ash requires understanding the nature of the cristobalite it contains. Volcanic cristobalite contains coupled substitutions of Al3+ and Na+ for Si4+; similar co-substitutions in synthetic cristobalite are known to modify the crystal structure, affecting t...

The RNA world hypothesis of the origin of life, in which RNA emerged as both enzyme and information carrier, is receiving solid experimental support. The prebiotic synthesis of biomolecules, the catalytic aid offered by mineral surfaces, and the vast enzymatic repertoire of ribozymes are only pieces of the origin of life puzzle; the full picture can only emerge if the pieces fit together by eit...

We have studied the Mg and Ca isotopic compositions of an unusual Allende inclusion dominated by hibonite, which is the most refractory and possibly the most primitive major oxide mineral. No 26Mg excess was found in spite of the high 27 Al/24Mg (1 > 103) of some samples, indicating an initial (26Al/27Al)0 < 2 X 10-7, a factor of 250 less than found in some other Allende inclusions. The upper l...

The identification of plant functional traits that can be linked to ecosystem processes is of wide interest, especially for predicting vegetational responses to climate change. Root diameter of the finest absorptive roots may be one plant trait that has wide significance. Do species with relatively thick absorptive roots forage in nutrient-rich patches differently from species with relatively f...