Note on Polarographic Determination of +6 Uranium

A polarographic method is proposed for determination of small amounts of +6 uranium. An aqueous solution of salicylic acid (1.6 g /l), sulphuric acid (0.4% v/ v) and thymol (0.009 %) is used as supporting electrolyte. This procedure is applicable in the concentration range from 5 to 50 μg of uranium per ml. of the solution used for polarographic measurement. Total amounts of 10 μg of uranium per sample can be determined with a standard error of ± 0.8 μg

Note on Polarographic Determination of +6 Uranium

A polarographic method is proposed for determination of small amounts of +6 uranium. An aqueous solution of salicylic acid (1.6 g /l), sulphuric acid (0.4% v/ v) and thymol (0.009 %) is used as supporting electrolyte. This procedure is applicable in the concentration range from 5 to 50 μg of uranium per ml. of the solution used for polarographic measurement. Total amounts of 10 μg of uranium per sample can be determined with a standard error of ± 0.8 μg

Polarographic Behaviour of +6 Uranium in a Mixture of Salycilic and Sulphuric Acid

The half- wave potential, the diffusion coefficient and the diffusion current constant of + 6 uranium in the supporting electrolyte containing 1.60 g/l salicylic acid, 0.4% v v sulphuric acid and 0.009 % thymol (as maximum suppressor) have been determined. The electrocapillary curve of mercury in this electrolyte is also given

Polarographic Behaviour of +6 Uranium in a Mixture of Salycilic and Sulphuric Acid

The half- wave potential, the diffusion coefficient and the diffusion current constant of + 6 uranium in the supporting electrolyte containing 1.60 g/l salicylic acid, 0.4% v v sulphuric acid and 0.009 % thymol (as maximum suppressor) have been determined. The electrocapillary curve of mercury in this electrolyte is also given

A light spot on the leaf of Nelumbium

The authors point to a special light spot, which is situated in the middle of the leaf of Nelumbium luteum Wild., which is cultivated in the pond of the Botanical Garden of the University in Zagreb. As the previous investigators of the anatomy of Nelumbium’s leaf (Wigand-Dennert) have neither described this spot precisely, nor have they given any explanation, the authors have examined the anatomy of this organ and tried to explain it. The light spot is especially characterised by unusually big stomata (56X32), which are more than twice as big as the ones on the blade (lamina) of the leaf. Their number is, according to this, much smaller (cca 70 pro mm\u272) than on the leaf itself (cca 550 pro mm2). The stomata are built of guard cells, which have no thickenings, neither anticlinal nor periclinal, and contain a lot of starch. Directly attached to the stomata is the lacunose parenchyma and the inercellular lacunes-system of the petiole. The stomata are very permeable for gases, what can easyly be shown by blowing the air through the petiole of a leaf which is placed under the water. This, and the elementary test with the cobaltpaper, show that the light spot is a pneumathodic organ sui generis — which deals as »a chimney« on the leaf of Nelumbium to intensify the transpiration and exchange of gases as a special hydrophytic adaptation. The details of the structure of this organ in comparation with the anatomy of the leaf can be seen on the added figures

Predicting Shine–Dalgarno Sequence Locations Exposes Genome Annotation Errors

In prokaryotes, Shine–Dalgarno (SD) sequences, nucleotides upstream from start codons on messenger RNAs (mRNAs) that are complementary to ribosomal RNA (rRNA), facilitate the initiation of protein synthesis. The location of SD sequences relative to start codons and the stability of the hybridization between the mRNA and the rRNA correlate with the rate of synthesis. Thus, accurate characterization of SD sequences enhances our understanding of how an organism's transcriptome relates to its cellular proteome. We implemented the Individual Nearest Neighbor Hydrogen Bond model for oligo–oligo hybridization and created a new metric, relative spacing (RS), to identify both the location and the hybridization potential of SD sequences by simulating the binding between mRNAs and single-stranded 16S rRNA 3′ tails. In 18 prokaryote genomes, we identified 2,420 genes out of 58,550 where the strongest binding in the translation initiation region included the start codon, deviating from the expected location for the SD sequence of five to ten bases upstream. We designated these as RS+1 genes. Additional analysis uncovered an unusual bias of the start codon in that the majority of the RS+1 genes used GUG, not AUG. Furthermore, of the 624 RS+1 genes whose SD sequence was associated with a free energy release of less than −8.4 kcal/mol (strong RS+1 genes), 384 were within 12 nucleotides upstream of in-frame initiation codons. The most likely explanation for the unexpected location of the SD sequence for these 384 genes is mis-annotation of the start codon. In this way, the new RS metric provides an improved method for gene sequence annotation. The remaining strong RS+1 genes appear to have their SD sequences in an unexpected location that includes the start codon. Thus, our RS metric provides a new way to explore the role of rRNA–mRNA nucleotide hybridization in translation initiation

Phosphorus and Nitrogen Transport in the Binational Great Lakes Basin Estimated Using SPARROW Watershed Models

AbstractEutrophication problems in the Great Lakes are caused by excessive nutrient inputs (primarily phosphorus, P, and nitrogen, N) from various sources throughout its basin. In developing protection and restoration plans, it is important to know where and from what sources the nutrients originate. As part of a binational effort, Midcontinent SPARROW (SPAtially Referenced Regression On Watershed attributes) models were developed and used to estimate P and N loading from throughout the entire basin based on nutrient inputs similar to 2002; previous SPARROW models only estimated U.S. contributions. The new models have a higher resolution (~2‐km2 catchments) enabling improved descriptions of where nutrients originate and the sources at various spatial scales. The models were developed using harmonized geospatial datasets describing the stream network, nutrient sources, and environmental characteristics affecting P and N delivery. The models were calibrated using loads from sites estimated with ratio estimator and regression techniques and additional statistical approaches to reduce spatial correlation in the residuals and have all monitoring sites equally influence model development. SPARROW results, along with interlake transfers and direct atmospheric inputs, were used to quantify the entire P and N input to each lake and describe the importance of each nutrient source. Model results can be used to compare loading and yields from various tributaries and jurisdictions

Toward a first-principles integrated simulation of tokamak edge plasmas

Performance of the ITER is anticipated to be highly sensitive to the edge plasma condition. The edge pedestal in ITER needs to be predicted from an integrated simulation of the necessary first-principles, multi-scale physics codes. The mission of the SciDAC Fusion Simulation Project (FSP) Prototype Center for Plasma Edge Simulation (CPES) is to deliver such a code integration framework by (1) building new kinetic codes XGC0 and XGC1, which can simulate the edge pedestal buildup; (2) using and improving the existing MHD codes ELITE, M3D-OMP, M3D-MPP and NIMROD, for study of large-scale edge instabilities called Edge Localized Modes (ELMs); and (3) integrating the codes into a framework using cutting-edge computer science technology. Collaborative effort among physics, computer science, and applied mathematics within CPES has created the first working version of the End-to-end Framework for Fusion Integrated Simulation (EFFIS), which can be used to study the pedestal-ELM cycles

PKD1 and PKD2 mutations in Slovenian families with autosomal dominant polycystic kidney disease

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disorder caused by mutations in at least two different loci. Prior to performing mutation screening, if DNA samples of sufficient number of family members are available, it is worthwhile to assign the gene involved in disease progression by the genetic linkage analysis. METHODS: We collected samples from 36 Slovene ADPKD families and performed linkage analysis in 16 of them. Linkage was assessed by the use of microsatellite polymorphic markers, four in the case of PKD1 (KG8, AC2.5, CW3 and CW2) and five for PKD2 (D4S1534, D4S2929, D4S1542, D4S1563 and D4S423). Partial PKD1 mutation screening was undertaken by analysing exons 23 and 31–46 and PKD2 . RESULTS: Lod scores indicated linkage to PKD1 in six families and to PKD2 in two families. One family was linked to none and in seven families linkage to both genes was possible. Partial PKD1 mutation screening was performed in 33 patients (including 20 patients from the families where linkage analysis could not be performed). We analysed PKD2 in 2 patients where lod scores indicated linkage to PKD2 and in 7 families where linkage to both genes was possible. We detected six mutations and eight polymorphisms in PKD1 and one mutation and three polymorphisms in PKD2. CONCLUSION: In our study group of ADPKD patients we detected seven mutations: three frameshift, one missense, two nonsense and one putative splicing mutation. Three have been described previously and 4 are novel. Three newly described framesfift mutations in PKD1 seem to be associated with more severe clinical course of ADPKD. Previously described nonsense mutation in PKD2 seems to be associated with cysts in liver and milder clinical course