A detailed determination of the a priori mixing angles in non-leptonic decays of hyperons

Non-leptonic Decays of Hyperons can provide a detailed determination of the a priori mixing angles that appear in physical hadrons in the approach in which non-perturbative flavor and parity violations are present in tiny pieces of the hadron mass operator. The determination of such angles in these decays will provide a bench mark to test their necessary universality-like property in other types of decays. Our main result is that the magnitudes of the a priori mixing angles can be determined quite accurately

Homologue expression of a fungal endo-1,4-β-Dxylanase using submerged and solid substrate fermentations

The xyn5 gene, which encodes an endo-β-1,4-xylanase (Xyn5), in Aspergillus niger GS1 was cloned into an expression cassette under the control of constitutive glyceraldhehyde-3-phosphate dehydrogenase gene promoter. The expression system was designed to produce the recombinant enzyme containing a six-histidine peptide fused to the carboxyl end of the protein. The efficiency of Xyn5 production under submerged (SmF) and solid-state (SSF) fermentation was investigated using the homologous cotransformed A. niger AB4.1. A productivity of 17.1 U/(l·h) was estimated for SSF and 3.2 U/(l·h) for SmF calculated at peak value of enzyme titers. Recombinant Xyn5 obtained by SSF on polyurethane fiber, was purified 5.1-fold by anion exchange and immobilized metal affinity chromatography, with 35.7% recovery. The purified recombinant enzyme showed an apparent molecular weight of 30 kDa and optimal activity (522 U/mg protein) at pH 5.5 and 50°C.Key words: Aspergillus niger GS1, xylanolytic activity, solid-state fermentation, homologue expression, polyurethane fiber

A Priori Mixed Hadrons, Weak Radiative and Non-leptonic Decays of Hyperons

A priori mixings of eigenstates in physical states are quantum mechanical effects well known in several realms of physics. The possibility that such effects are also present in particle physics, in the form of flavor and parity mixings, is studied. Applications to weak radiative and non-leptonic decays of hyperons are discussed

The very lithium rich post-AGB SB2 binary HD172481

Double lined spectroscopic binaries in an evolved stage of evolution are expected to be extremely rare since they must consist of equally luminous and thus almost equally evolved objects, which requires an extremely similar initial mass. In this contribution we discuss such rare double evolved SB2 system: HD172481. This binary includes an F-type post-AGB object and an M-type AGB companion. The spectrum shows a surprisingly strong LiI 670.8nm line with an equivalent width of 54mA yielding a lithium abundance of log(Li)=3.6. Several explanations for this huge lithium content are explored.Comment: 7 pages, 5 figures, to appear in the proceedings of: "Post-AGB Objects (Proto-Planetary Nebulae) as a Phase of Stellar Evolution", held in Torun, Poland, July 5-7, 2000; eds. R. Szczerba, R. Tylenda, and S.K. Gorny. See also the accepted A&A paper at http://xxx.lanl.gov/abs/astro-ph/001048

Controls on gut phosphatisation : the trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah)

Despite being internal organs, digestive structures are frequently preserved in Cambrian Lagerstätten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alternative to appendage morphology for inferences on their biology. Here we describe the phosphatised digestive structures of three trilobite species from the Cambrian Weeks Formation Lagerstätte (Utah). Their exquisite, three-dimensional preservation reveals unique details on trilobite internal anatomy, such as the position of the mouth and the absence of a differentiated crop. In addition, the presence of paired pygidial organs of an unknown function is reported for the first time. This exceptional material enables exploration of the relationships between gut phosphatisation and the biology of organisms. Indeed, soft-tissue preservation is unusual in these fossils as it is restricted to the digestive structures, which indicates that the gut played a central role in its own phosphatisation. We hypothesize that the gut provided a microenvironment where special conditions could develop and harboured a source of phosphorus. The fact that gut phosphatization has almost exclusively been observed in arthropods could be explained by their uncommon ability to store ions (including phosphorous) in their digestive tissues. However, in some specimens from the Weeks Formation, the phosphatisation extends to the entire digestive system, suggesting that trilobites might have had some biological particularities not observed in modern arthropods. We speculate that one of them might have been an increased capacity for ion storage in the gut tissues, related to the moulting of their heavily-mineralised carapace

Experimental Reconstruction of Lomonosov's Discovery of Venus's Atmosphere with Antique Refractors During the 2012 Transit of Venus

In 1761, the Russian polymath Mikhail Vasilievich Lomonosov (1711-1765) discovered the atmosphere of Venus during its transit over the Sun's disc. In this paper we report on experimental reenactments of Lomonosov's discovery with antique refractors during the transit of Venus June 5-6, 2012. We conclude that Lomonosov's telescope was fully adequate to the task of detecting the arc of light around Venus off the Sun's disc during ingress or egress if proper experimental techniques as described by Lomonosov in his 1761 report are employed.Comment: 14 pages, 9 figure

Preparation and in vitro evaluation of 177Lu-iPSMA-RGD as a new heterobivalent radiopharmaceutical

This study aimed to synthesize a new 177Lu-iPSMA-RGD heterobivalent radiopharmaceutical, as well as to assess the in vitro radiopharmaceutical potential to target cancer cells overexpressing PSMA and a(v) b(3) integrins. The radiotracer prepared with a radiochemical purity of 98.8 ± 1.0% showed stability in human serum, specific recognition with suitable affinity to PSMA and a(v)b(3) integrins, and capability to inhibit cancer cell proliferation and VEGF signaling (antiangiogenic effect). Results warrant further preclinical studies to establish the 177Lu-iPSMA-RGD potential as a dual therapeutic radiopharmaceutical.CONACyT-CB-2016-01-28152

Epistemological access through lecture materials in multiple modes and language varieties: the role of ideologies and multilingual literacy practices in student evaluations of such materials at a South African University

This paper seeks to address the ways in which ideology and literacy practices shape the responses of students to an ongoing initiative at the University of the Western Cape aimed at diversifying options for epistemological access, specifically the language varieties and the modes in which parts of the curriculum for a third year linguistics module are delivered. Students’ responses to the materials in English and in two varieties of Afrikaans and isiXhosa (as mediated in writing vs orally) are determined, and used as basis to problematize decisions on language variety and mode in language diversification initiatives in Higher Education in South Africa. The findings of the paper are juxtaposed against particular group interests in the educational use of a language as well as differences in the affordances and impact of different modes of language use. The paper suggests that beyond the euphoria of using languages other than English in South African Higher Education, several issues (such as entrenched language practices, beliefs and language management orientations) require attention if the goals of transformation in this sector are to be attained

Microbial catabolic activities are naturally selected by metabolic energy harvest rate

The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate

Prospective study of patients with persistent symptoms of dengue in Brazil

Dengue is an arboviral infection clinically recognized as an acute and self-limited disease. Persistence of dengue symptoms is known, but it has been little studied. The aim of this study was to characterize persistent symptoms in 113 patients with dengue followed up clinically and by laboratory testing at a tertiary hospital. Symptoms that persisted for more than 14 days were observed in 61 (54.0%) patients, and six (6.2%) of them had symptoms for 6 months or more. The persistent symptoms identified were myalgia, weakness, hair loss, memory loss, reduced resistance to physical effort, headache, reasoning problems, arthralgia, sleepiness- and emotional lability. The progression to persistent symptoms was significantly associated with hospitalization, older age, more severe disease, the presence of bleeding and comorbidities upon univariate analysis. Upon multivariate analysis, the presence of persistent symptoms continued to be significantly associated only with increased age and dengue with warning signs. The platelet count during the acute phase of the disease was significantly lower in the group with persistent symptoms. In conclusion, the frequency of progression to persistent symptoms in dengue is relevant in patients seen at a tertiary hospital and the persistence of symptoms is more common in patients with dengue with warning signs