Silicon and chromium stable isotopic systematics during basalt weathering and lateritisation: A comparison of variably weathered basalt profiles in the Deccan Traps, India

Global biomass production is fundamentally affected by the hydrological cycling of elements at the Earth's surface. Continental weathering processes are the major source for most bio-essential elements in marine environments and therefore affect primary productivity. In addition, critical zone biomass depends on energy and chemical exchange reactions in weathering profiles. The latter reservoirs are in turn influenced by different climatic conditions that control weathering and pore water parameters like pH and Eh, which regulate mineral break down rates and dictate the mobility and mass flux of elements. Two Deccan Traps basalt weathering profiles of contrasting age and alteration intensity provide a natural laboratory for investigating the effects of rock alteration on Si and Cr and their isotopic. systematics. The Quaternary Chhindwara profile has progressed to a moderate degree of alteration (saprolite), while the Paleogene Bidar example displays an extremely altered laterite. The Chhindwara saprolite profile shows a near uniform Cr and Si concentration and isotopic composition, whereas the Bidar laterite profile is characterised by an intense loss of Si, a large enrichment of Cr within the most altered uppermost levels, and a wide range of Cr stable isotope ratios (-0.85 to 0.36 parts per thousand delta Cr-53/52). A co-variation between Si and Cr isotopes, as well as their co-variation with iron content, provides empirical evidence that iron redistribution within the profile has a large effect on Cr mobility and Si isotopic fractionation. Therefore, it is concluded that iron oxides exert a primary control over the isotopic composition of both Cr and Si in pore waters of laterites. Since laterite formation is promoted by tropical climates, the results of this study provide new evidence to suggest that the hydrological Cr and Si fluxes originating from continental weathering have changed in accordance with large-scale, deep time climate variation and continental plate configuration. An increased flux of Si and greater magnitude of Cr mobility and isotopic fractionation are possibly amplified under CO2-rich, greenhouse episodes and/or when large landmasses were tectonically arranged at near equatorial latitudes

Distribution of biogenic silica in the scheldt estuary

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Infantile spinal muscular atrophy: Therapeutic (R)evolution

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder. The infantile form is the most common genetic cause of infantile death due to respiratory insufficiency. The disorder is caused by the premature death of motor neurons of anterior horn, leading to progressive weakness and muscular atrophy. Longtime considered as untreatable, the pathology knew a real revolution during the last two years. Views on this terrible disease have completely changed, changing, therefore, the management of the patients and constituting new challenge

Storage of nutriments in black anthropogenic soils from the East-African Great Lakes Region

In the East-African Great Lakes Region, low crop yields due to widespread soil infertility involve difficulties to cope with demographic pressure. Banana cropping systems are widespread and crucial for people livelihood. Improving their sustainability requires a better understanding of nutrient dynamics and soil fertility. We studied highly weathered soils in four sites from Rwanda and Burundi. The soils differed in parent rock: granite, shale, and other pelitic rocks. In four homesteads at each site, soils were sampled as a function of depth and distance to farmer’s house. We determined soil physico-chemical properties and total elemental contents, as well as soil mineralogical constitution.Typical black anthropogenic soils similar to the Amazonian Dark Earths (Terra Preta) occurred where banana cropping was ancient and soils benefited from frequent supply of organic manure and ash cooking residues. Close to home buildings, the thickness of dark Ah horizons could be above 160 cm. Soil management practices and accumulation of organic matter significantly increased soil porosity and root exploration allowing enhanced uptake of water and nutrients, thereby increasing biomass of banana plants. PCA-analysis (Matlab Student Version R2007a)involving eight soil properties yielded to 78% of total variance born by the two first principal components (PC). PC1 (53%) was positively correlated to CEC and total contents of C, Ca, P, and Mg. PC2 (25%) was defined by a strong negative correlation between total Fe content and total contents of Si and K. Our data thus show that two major types of soil properties discriminated the soil samples: (1) organic matter content and major plant nutrients (Ca, Mg, P), both linked to past and current soil management practices, (2) nature of parent rock, linked to the abundance of iron and the occurrence of muscovite as residual mineral

La xanthomatose cérébro-tendineuse, une maladie métabolique rare, grave mais curable.

Cerebrotendinous xanthomatosis (CTX) is a rare and treatable autosomal recessive disease. The diagnosis should be suspected in the presence of a suggestive clinical triad characterized by early-onset cataract, tendinous xanthomata and neurological symptoms and signs, notably cerebellar ataxia, mental retardation and pyramidal syndrome.The diagnosis is confirmed by demonstrating an increased blood level of cholestanol, or/and by molecular genetic analysis.In typical cases, brain MRI shows bilateral hyperintensity of the cerebellar nucleus dentatus together with cerebral atrophy and leukoencephalopathy. The treatment is based on the administration of chenodeoxycholic acid. The aim is to restore the negative feedback on the enzymatic cascade altered by mutation in the gene CYP27 which induces a 27-hydroxylase deficiencyinfo:eu-repo/semantics/publishe

Cost-effectiveness of spinal muscular atrophy newborn screening based on real-world data in Belgium

The objective of the study was to assess the cost-effectiveness of real-world spinal muscular atrophy newborn screening followed by treatment. We modeled the lifetime cost-effectiveness of the spinal muscular atrophy newborn screening followed by treatment (screening) compared to treatment without screening (no screening) from the Belgian healthcare perspective. Real-world data, including quality of life, costs, and motor development data, were collected on 12 patients identified by screening and 43 patients identified by their symptoms. "Screening" was associated with slightly higher healthcare costs (€ 6,858,061 vs. € 6,738,120) but more quality-adjusted life years (QALY) (40.95 vs. 20.34) compared to "no screening", leading to an incremental cost-effectiveness ratio of € 5,820 per QALY gained. "Screening" was dominant from a societal perspective (negative incremental costs: € -14,457; incremental QALY = 20.61), when incorporating the burden on caregivers (negative incremental costs = € -74,353; incremental QALY = 27.51), and when the treatment was chosen by the parents (negative incremental costs = € -2,596,748; incremental QALY = 20.61). Spinal muscular atrophy newborn screening coupled with early treatment is thus cost-effective compared with late treatment following clinical diagnosis and is dominant when societal perspective, caregiver burden, and treatment based on parental preference were considered