A new view of quiet-Sun topology from Hinode/SOT

Context. With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature. Aims. Topology is a tool to explain the complexity of the magnetic field, the occurrence of reconnection processes, and the heating of the corona. This Letter aims to give new insights to these different topics. Methods. Using a high-resolution Hinode/SOT observation of the line-of-sight magnetic field on the photosphere, we calculate the three dimensional magnetic field in the region above assuming a potential field. From the 3D field, we determine the existence of null points in the magnetic configuration. Results. From this model of a continuous field, we find that the distribution of null points with height is significantly different from that reported in previous studies. In particular, the null points are mainly located above the bottom boundary layer in the photosphere (54%) and in the chromosphere (44%) with only a few null points in the corona (2%). The density of null points (expressed as the ratio of the number of null points to the number of photospheric magnetic fragments) in the solar atmosphere is estimated to be between 3% and 8% depending on the method used to identify the number of magnetic fragments in the observed photosphere. Conclusions. This study reveals that the heating of the corona by magnetic reconnection at coronal null points is unlikely. Our findings do not rule out the heating of the corona at other topological features. We also report the topological complexity of the chromosphere as strongly suggested by recent observations from Hinode/SOT

\u3ci\u3eIn Vitro\u3c/i\u3e Stable Isotope Labeling for Discovery of Novel Metabolites by Liquid Chromatography-Mass Spectrometry: Confirmation of γ-Tocopherol Metabolism in Human A549 Cell

A general approach for discovering novel catabolic metabolites from a parent biocompound was developed and validated on metabolism of γ-tocopherol in human A549 cell. Method is based on LC-MS analysis of in vitro stable isotope labeled metabolites and assumes that a parent compound and its metabolites share a common functional group that can be derivatized by well-documented reagents. In this method, two equal aliquots of extracted metabolites are separately derivatized with isotope-coded (heavy) and non-isotope-coded (light) form of derivatizing reagent, mixed at 1:1 ratio and analyzed using LC-MS. The metabolites with common functional group are then easily recognized by determination of a chromatographically co-eluted pair of isotopomers (MS doublet peaks) with similar peak intensities and mass difference corresponding to the mass difference between heavy and light form of derivatization reagent. The feasibility of this approach was demonstrated and validated by identification of products of γ-tocopherol catabolism in human A549 cell culture media using N-methyl-nicotinic acid N-hydroxysuccinimide ester (C1-NANHS) and Nmethyl- d3-nicotinic acid N-hydroxysuccinimide ester (C1-d3-NANHS) derivatizing reagent. Overall four γ-tocopherol metabolites were identified including 9\u27-COOH, 11\u27-COOH, 13\u27-COOH and 13\u27-OH. In addition, the developed LC-MS method can also be used for the fast and sensitive quantitative analysis of γ-tocopherol and other forms of vitamin E related compounds

Influence of dietary constituents on intestinal absorption of aluminum

Orally-ingested aluminum compounds have been implicated in the development of dialysis encephalopathy, osteomalacic dialysis osteodystrophy and other disorders in both hemodialyzed and nonhemodialyzed patients suffering from chronic renal failure [1–10]. Both dialysate aluminum content [7, 11, 12] and aluminum-containing phosphate binding agents [12–15] have been identified as contributing to hyperaluminemia in uremic patients. The health threat from dialysate fluids has been reduced by the recommendation that the dialysate contains less than 10 µg/liter of aluminum [16]. Alternative phosphate-binding agents which do not contain aluminum are available but these agents are not free of problems [17], and uremic patients continue to ingest significant doses of aluminum-containing phosphate binding agents.Aluminum is the most common metal in the biosphere of humans but, aside from uremic patients, causes no widespread toxicity. This may be as a result of the extremely limited solubility of aluminum at the pH range of the small intestine and blood [18]. Advances in analytical chemistry have made it possible to measure picogram quantities of aluminum in body fluids, thus enabling accurate determination of plasma aluminum levels in the part per billion (µg/liter) range. These analytical techniques have shown that orally ingested aluminum-containing antacids elevate plasma aluminum levels in man [13]. Balance studies monitoring aluminum absorption and elimination revealed an average positive balance from 23 to 313mg of aluminum per day when diets were supplemented with 1 to 3g of aluminum per day [15]. These studies show that a small fraction of the ingested aluminum is absorbed. This absorption presents potential toxic effects to uremic patients whose ability to eliminate aluminum is impaired.In addition, Slanina et al [19] have shown that addition of citric acid to aluminum-supplemented dietary regimens results in blood aluminum levels that are significantly higher than those found in subjects treated with aluminum-supplemented dietary regimens alone. This result suggests that dietary factors may contribute to aluminum absorption.This study was undertaken to determine if the form of aluminum present in the intestinal lumen significantly affects the absorption of aluminum following oral ingestion

An Automated Method for the Analysis of Stable Isotope Labeling Data in Proteomics

An algorithm is presented for the generation of a reliable peptide component peak table from liquid chromatography-mass spectrometry (LC-MS) and subsequent quantitative analysis of stable isotope coded peptide samples. The method uses chemical noise filtering, charge state fitting, and deisotoping toward improved analysis of complex peptide samples. Overlapping peptide signals in mass spectra were deconvoluted by correlation with modeled peptide isotopic peak profiles. Isotopic peak profiles for peptides were generated in silico from a protein database producing reference model distributions. Doublets of heavy and light labeled peak clusters were identified and compared to provide differential quantification of pairs of stable isotope coded peptides. Algorithms were evaluated using peptides from digests of a single protein and a seven-protein mixture that had been differentially coded with stable isotope labeling agents and mixed in known ratios. The experimental results correlated well with known mixing ratios

Proteomic analysis of Arabidopsis glutathione S-transferases from benoxacor- and copper-treated seedlings

Glutathione S-transferases (GSTs) are involved in many stress responses in plants, for example, participating in the detoxification of xenobiotics and limiting oxidative damage. Studies examining the regulation of this gene family in diverse plant species have focused primarily on RNA expression. A proteomics method was developed to identify GSTs expressed in Arabidopsis seedlings and to determine how the abundance of these proteins changed in response to copper, a promoter of oxidative stress, and benoxacor, a herbicide safener. Eight GSTs were identified in seedlings grown under control conditions, and only one, AtGSTU19, was induced by benoxacor. In contrast, four GSTs, AtGSTF2, AtGSTF6, AtGSTF7, and AtGSTU19, were significantly more abundant in copper-treated seedlings. The different responses to these treatments may reflect the potential for copper to affect many more aspects of plant growth and physiology compared with a herbicide safener. Differences between RNA and protein expression of GSTs indicate that both transcriptional and translational mechanisms are involved in regulation of GSTs under these conditions

Report: The 62nd Annual Caddo Conference and 27th Annual East Texas Archeological Conference, Tyler, Texas, February 28 and 29, 2020

The 62nd Caddo Conference and 27th East Texas Archeological Conference was held at the University Center on the campus of the University of Texas at Tyler on February 28 and 29, 2020. The conference was dedicated to the rebuilding of public facilities at Caddo Mounds State Historic Site. These facilities had been destroyed by a tornado in 2019. The conference organizers were Thomas Guderjan, Colleen Hanratty, Cory Sills, Christy Simmons (University of Texas at Tyler), Keith Eppich (Tyler Junior College), Anthony Souther (Caddo Mounds State Historic Site), Amanda Regnier (Oklahoma Archeological Survey), Mark Walters (Texas Historical Commission Steward). Sponsors included The Center for Social Science Research and Department of Social Sciences, University of Texas at Tyler, Humanities Texas, Kevin Stingley, Arkansas Archeological Survey, Beta Analytic, Inc., Friends of Northeast Texas Archeology, East Texas Archeological Society, Maya Research Program, Tejas Archeology, Tyler Junior College, Gregg County Historical Museum, the American Indian Heritage Day of Texas organization, and the Caddo Nation. Before the formal program began, a preconference gathering was held at ETX Brewing Company at 221 S Broadway Avenue in Tyler on Thursday evening, February 27th. Approximately 250 people participated in the joint conferences

A System F accounting for scalars

The Algebraic lambda-calculus and the Linear-Algebraic lambda-calculus extend the lambda-calculus with the possibility of making arbitrary linear combinations of terms. In this paper we provide a fine-grained, System F-like type system for the linear-algebraic lambda-calculus. We show that this "scalar" type system enjoys both the subject-reduction property and the strong-normalisation property, our main technical results. The latter yields a significant simplification of the linear-algebraic lambda-calculus itself, by removing the need for some restrictions in its reduction rules. But the more important, original feature of this scalar type system is that it keeps track of 'the amount of a type' that is present in each term. As an example of its use, we shown that it can serve as a guarantee that the normal form of a term is barycentric, i.e that its scalars are summing to one

Electrosynthesis of Aryliminophosphoranes in Continuous Flow

A practical electrochemical method for synthesizing aryliminophosphoranes from widely available nitro(hetero)arenes in a continuous-flow system is presented. The utilization of flow technology offers several advantages to our approach, including the elimination of the need for a supporting electrolyte and enhanced scalability. Our method demonstrates good tolerance towards various functional groups, with electron-deficient nitroarenes being particularly suitable for this strategy. In addition, we have demonstrated the versatility of aryliminophosphoranes as intermediates in synthesizing anilines, amines, and amides. To further enhance the utility of our approach, we have developed a telescoped method that utilizes a tube-in-tube setup for the in-situ production of isocyanates

Patterned Protein Microarrays for Bacterial Detection

Abstract Patterned microarrays of antibodies were fabricated and tested for their ability to bind targeted bacteria. These arrays were used in a series of bacterial immunoassays to detect E. coli 0157:H7 and Renibacterium Salmoninarum (RS). Microarrays were fabricated using microcontact printing (µCP) and characterized using scanning probe microscopy (SPM). The high-resolution SPM imaging showed that targeted bacteria had a higher binding selectivity to complementary antibody patterns than to unfunctionalized regions of the substrate. Additional studies indicated a significant reduction in binding of bacteria when the microarrays were exposed to non-specific bacteria. These studies demonstrate how protein microarrays could be developed into useful platforms for sensing microorganisms.