324 research outputs found

    Constraining the source regions of lunar meteorites using orbital geochemical data

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    Lunar meteorites provide important new samples of the Moon remote from regions visited by the Apollo and Luna sample return missions. Petrologic and geochemical analysis of these meteorites, combined with orbital remote-sensing measurements have enabled additional discoveries about the composition and age of the lunar surface on a global scale. However, the interpretation of these samples is limited by the fact that we do not know the source region of any individual lunar meteorite. Here we investigate the link between meteorite and source region on the Moon using the Lunar Prospector Gamma Ray Spectrometer remote sensing dataset for the elements Fe, Ti and Th. The approach has been validated using Apollo and Luna bulk regolith samples and we have applied it to 48 meteorites excluding paired stones. Our approach is able broadly to differentiate the best compositional matches as potential regions of origin for the various classes of lunar meteorites. Basaltic and intermediate-Fe regolith breccia meteorites are found to have the best constrained potential launch sites, with some impact breccias and pristine mare basalts also having reasonably well defined potential source regions. Launch areas for highland feldspathic meteorites are much less well constrained and the addition of another element, such as Mg, will probably be required to identify potential source regions for these

    Identification of novel oyster allergens using a combined transcriptomic and proteomic approach for improved component resolved diagnosis

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    Background: Increasing production and consumption of mollusc is associated with the rise in prevalence of mollusc allergy worldwide, currently ranging from 0.15% to 1.3% of the general population. However, the elucidation of mollusc allergens for better diagnostics still lags behind other seafood groups such as fish and crustacean. Genomic data have been utilized previously for improved identification of non-food allergens by performing similarity searching using the BLAST program. Based on the published genome of the Pacific oyster (Crassostrea gigas) we aimed to identify the complete potential oyster allergen repertoire using ioinformatics analysis, and to investigate identified protein allergenicity using a combination of immuno-chemical methods and proteomic analysis. Results: Ninety-five potential allergenic proteins of the Pacific oyster were discovered using in silico analyses. These proteins were of same protein family and had more than 50% amino acid identity with their homologous allergens. The allergenicity of these proteins was characterized using a combination of immunoassay and transcriptome-derived proteomics analyses. However The 2D-immunoblotting results showed only twenty two IgE-reactive spots in the raw extract of the Pacific oyster, and six spots in the heated extract. The identity of these IgE-reactive proteins was investigated by mass spectrometry. Sixteen allergens were identified, some with two or more isoforms. Conclusions: The combination of genomics coupled to proteomics and IgE-reactivity profiling is a powerful method for the identification of novel allergens from food sources. Using this combination approach we were able to expand the current knowledge on IgE-reactivity to various proteins of the Pacific oyster. These newly identified allergens and knowledge of their gene sequences will facilitate the development of improved component resolved diagnosis and future immunotherapy approach for oyster allergy

    Pollen and spores as biological recorders of past ultraviolet irradiance

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    Solar ultraviolet (UV) irradiance is a key driver of climatic and biotic change. Ultraviolet irradiance modulates stratospheric warming and ozone production, and influences the biosphere from ecosystem-level processes through to the largest scale patterns of diversification and extinction. Yet our understanding of ultraviolet irradiance is limited because no method has been validated to reconstruct its flux over timescales relevant to climatic or biotic processes. Here, we show that a recently developed proxy for ultraviolet irradiance based on spore and pollen chemistry can be used over long (105 years) timescales. Firstly we demonstrate that spatial variations in spore and pollen chemistry correlate with known latitudinal solar irradiance gradients. Using this relationship we provide a reconstruction of past changes in solar irradiance based on the pollen record from Lake Bosumtwi in Ghana. As anticipated, variations in the chemistry of grass pollen from the Lake Bosumtwi record show a link to multiple orbital precessional cycles (19-21 thousand years). By providing a unique, local proxy for broad spectrum solar irradiance, the chemical analysis of spores and pollen offers unprecedented opportunities to decouple solar variability, climate and vegetation change through geologic time and a new proxy with which to probe the Earth system

    Clinical aspects of short-chain acyl-CoA dehydrogenase deficiency

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    Short-chain acyl-CoA dehydrogenase deficiency (SCADD) is an autosomal recessive inborn error of mitochondrial fatty acid oxidation. SCADD is biochemically characterized by increased C4-carnitine in plasma and ethylmalonic acid in urine. The diagnosis of SCADD is confirmed by DNA analysis showing SCAD gene mutations and/or variants. SCAD gene variants are present in homozygous form in approximately 6% of the general population and considered to confer susceptibility to development of clinical disease. Clinically, SCADD generally appears to present early in life and to be most frequently associated with developmental delay, hypotonia, epilepsy, behavioral disorders, and hypoglycemia. However, these symptoms often ameliorate and even disappear spontaneously during follow-up and were found to be unrelated to the SCAD genotype. In addition, in some cases, symptoms initially attributed to SCADD could later be explained by other causes. Finally, SCADD relatives of SCADD patients as well as almost all SCADD individuals diagnosed by neonatal screening remained asymptomatic during follow-up. This potential lack of clinical consequences of SCADD has several implications. First, the diagnosis of SCADD should never preclude extension of the diagnostic workup for other potential causes of the observed symptoms. Second, patients and parents should be clearly informed about the potential lack of relevance of the disorder to avoid unfounded anxiety. Furthermore, to date, SCADD is not an optimal candidate for inclusion in newborn screening programs. More studies are needed to fully establish the relevance of SCADD and solve the question as to whether SCADD is involved in a multifactorial disease or represents a nondisease

    Lunar meteorite Northwest Africa 11962: A regolith breccia containing various examples of titanium-rich lunar volcanism and the high alkali suite.

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    The meteorite Northwest Africa (NWA) 11962 has been recently classified as a lunar regolith breccia. For the present study, the clasts and the matrix of NWA 11962 have been characterized by optical and electron microscopy along with electron microprobe analyses. The meteorite has a glassy impact melt matrix, which accounts for 35% of the surface area in the thin sections examined, and which contains a very large variety of different lithic clasts, monomineralic clasts, and glass fragments. Lithic clasts include numerous fragments of quartz monzogabbro and lunar felsite, which are quite rare lithologies in the lunar alkali suite. However, the most abundant component in the breccia are gabbroic clasts. The mineral chemistry of the pyroxenes in these gabbroic clasts and the chemistry of various types of glasses in the breccia indicate an origin of the regolith from an area with low-Ti to high-Ti mare basalt volcanism. In addition to the peculiar petrographic characteristics of NWA 11962, the possible pairing relation with the NWA 4472/4485 group of lunar meteorites is discussed

    Artificial tektites: an experimental technique for capturing the shapes of spinning drops

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    Determining the shapes of a rotating liquid droplet bound by surface tension is an archetypal problem in the study of the equilibrium shapes of a spinning and charged droplet, a problem that unites models of the stability of the atomic nucleus with the shapes of astronomical-scale, gravitationally-bound masses. The shapes of highly deformed droplets and their stability must be calculated numerically. Although the accuracy of such models has increased with the use of progressively more sophisticated computational techniques and increases in computing power, direct experimental verification is still lacking. Here we present an experimental technique for making wax models of these shapes using diamagnetic levitation. The wax models resemble splash-form tektites, glassy stones formed from molten rock ejected from asteroid impacts. Many tektites have elongated or ‘dumb-bell’ shapes due to their rotation mid-flight before solidification, just as we observe here. Measurements of the dimensions of our wax ‘artificial tektites’ show good agreement with equilibrium shapes calculated by our numerical model, and with previous models. These wax models provide the first direct experimental validation for numerical models of the equilibrium shapes of spinning droplets, of importance to fundamental physics and also to studies of tektite formation

    A generic emergency protocol for patients with inborn errors of metabolism causing fasting intolerance: A retrospective, single-center study and the generation of www.emergencyprotocol.net

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    Patients with inborn errors of metabolism causing fasting intolerance can experience acute metabolic decompensations. Long-term data on outcomes using emergency letters are lacking. This is a retrospective, observational, single-center study of the use of emergency letters based on a generic emergency protocol in patients with hepatic glycogen storage diseases (GSD) or fatty acid oxidation disorders (FAOD). Data on hospital admissions, initial laboratory results, and serious adverse events were collected. Subsequently, the website www.emergencyprotocol.net was generated in the context of the CONNECT MetabERN eHealth project following multiple meetings, protocol revisions, and translations. Representing 470 emergency protocol years, 127 hospital admissions were documented in 54/128 (42%) patients who made use of emergency letters generated based on the generic emergency protocol. Hypoglycemia (here defined as glucose concentration 5 years. Convulsions, coma, or death was not documented. By providing basic information, emergency letters for individual patients with hepatic GSD or the main FAOD can be generated at www.emergencyprotocol.net, in nine different languages. Generic emergency protocols are safe and easy for home management by the caregivers and the first hour in-hospital management to prevent metabolic emergencies in patients with hepatic GSD and medium-chain Acyl CoA dehydrogenase deficiency. The website www.emergencyprotocol.net is designed to support families and healthcare providers to generate personalized emergency letters for patients with hepatic GSD and the main FAOD
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