Distribution of natural radionuclide40K in biotic and abiotic components of the Cauvery river system,Tiruchirapalli, India

Abiotic components like water and sediment, and biotic components such as mussels, fish and grass collected from Cauvery river at Tiruchirapalli were analysed for⁴⁰K activity. The highest level of⁴⁰K activity was found in the sediment (342 mBq g^-1 dry weight) and the lowest activity was found in water (2·209 mBq ml⁻¹). In the freshwater musselParreysia favidens (Benson)⁴⁰K activity was estimated in the total soft tissues and shells of mussels belonging to three different size groups. In all the size groups⁴⁰K activity was two times higher in shells (68–39 mBq g^-1 fresh weight) than in the total soft tissues (25–17 mBq g^-1 fresh weight). The results indicate that the younger mussels accumulated more⁴⁰K than the older ones. The ability of internal organs of mussels belonging to group III to accumulate⁴⁰K was in the following order: gills > digestive gland > foot > mantle. The values ranged from 47 to 18 mBq g⁻¹ fresh weight in the various organs. Concentration of⁴⁰K in the mussel was distinctly higher than in the grassEchinochloa colonum (J Koenig) (95 mBq g⁻¹ fresh weight), and the concentration of⁴⁰K in the bone of the fishCirrhina cirrhosa (Bloch) (126 mBq g⁻¹ fresh weight) was higher than to that of muscle (113 mBq g⁻¹ fresh weight)     

Pebrine diagnosis using quantitative phase imaging and machine learning

Pebrine is the most dreaded infectious disease of the silkworm and has devastated sericulture in Europe during the 18th century. Thereafter, if it is detected, the crop is burned to prevent further dissemination. The conventional microscopic examination of moth's body fluid is erroneous and it exacerbates on Metarhizium anisopliae (MA) contaminated test samples. This is due to the resemblance of pebrine and MA spores in the microscopic examination. Therefore, this study aims to demonstrate an efficient pebrine detection technique. In the proposed method, a motorised brightfield microscope is custom-made to acquire focused and defocused images of test spores. These images are used to produce quantitative phase images of the spores by the transport of intensity equation method. The phase images' histogram of oriented gradients feature is used by a machine learning classifier to categorise the spores. This system classified 92 pebrine and 185 MA spores with an accuracy of 97% at 0.04 seconds/spore. The duration taken for image acquisition is 2.5 minutes per sample (10 fields of view covering an area of 302 × 260 μm²). The proposed method shows reliable results in pebrine diagnosis and would be an efficient alternative for current approaches.     

Differences in evolutionary pressure acting within highly conserved ortholog groups

Background  

In highly conserved widely distributed ortholog groups, the main evolutionary force is assumed to be purifying selection that enforces sequence conservation, with most divergence occurring by accumulation of neutral substitutions. Using a set of ortholog groups from prokaryotes, with a single representative in each studied organism, we asked the question if this evolutionary pressure is acting similarly on different subgroups of orthologs defined as major lineages (e.g. Proteobacteria or Firmicutes).     

GSH Transport in Immortalized Mouse Brain Endothelial Cells

We have previously shown GSH transport across the blood-brain barrier in vivo and expression of transport in Xenopus laevis oocytes injected with bovine brain capillary mRNA. In the present study, we have used MBEC-4, an immortalized mouse brain endothelial cell line, to establish the presence of Na+-dependent and Na+-independent GSH transport and have localized the Na+-dependent transporter using domain-enriched plasma membrane vesicles. In cells depleted of GSH with buthionine sulfoximine, a significant increase of intracellular GSH could be demonstrated only in the presence of Na+. Partial but significant Na+ dependency of [35S]GSH uptake was observed for two GSH concentrations in MBEC-4 cells in which gamma-glutamyltranspeptidase and gamma-glutamylcysteine synthetase were inhibited to ensure absence of breakdown and resynthesis of GSH. Uniqueness of Na+-dependent uptake in MBEC-4 cells was confirmed with parallel uptake studies with Cos-7 cells that did not show this activity. Molecular form of uptake was verified as predominantly GSH, and very little conversion of [35S]cysteine to GSH occurred under the same incubation conditions. Poly(A)+ RNA from MBEC expressed GSH uptake with significant (approximately 40-70%) Na+ dependency, whereas uptake expressed by poly(A)+ RNA from HepG2 and Cos-1 cells was Na+ independent. Plasma membrane vesicles from MBEC were separated into three fractions (30, 34, and 38% sucrose, by wt) by density gradient centrifugation. Na+-dependent glucose transport, reported to be localized to the abluminal membrane, was found to be associated with the 38% fraction (abluminal). Na+-dependent GSH transport was present in the 30% fraction, which was identified as the apical (luminal) membrane by localization of P-glycoprotein 170 by western blot analysis. Localization of Na+-dependent GSH transport to the luminal membrane and its ability to drive up intracellular GSH may find application in the delivery of supplemented GSH to the brain in vivo.