Recent, independent and anthropogenic origins of Trypanosoma cruzi hybrids.

The single celled eukaryote Trypanosoma cruzi, a parasite transmitted by numerous species of triatomine bug in the Americas, causes Chagas disease in humans. T. cruzi generally reproduces asexually and appears to have a clonal population structure. However, two of the six major circulating genetic lineages, TcV and TcVI, are TcII-TcIII inter-lineage hybrids that are frequently isolated from humans in regions where chronic Chagas disease is particularly severe. Nevertheless, a prevalent view is that hybridisation events in T. cruzi were evolutionarily ancient and that active recombination is of little epidemiological importance. We analysed genotypes of hybrid and non-hybrid T. cruzi strains for markers representing three distinct evolutionary rates: nuclear GPI sequences (n = 88), mitochondrial COII-ND1 sequences (n = 107) and 28 polymorphic microsatellite loci (n = 35). Using Maximum Likelihood and Bayesian phylogenetic approaches we dated key evolutionary events in the T. cruzi clade including the emergence of hybrid lineages TcV and TcVI, which we estimated to have occurred within the last 60,000 years. We also found evidence for recent genetic exchange between TcIII and TcIV and between TcI and TcIV. These findings show that evolution of novel recombinants remains a potential epidemiological risk. The clearly distinguishable microsatellite genotypes of TcV and TcVI were highly heterozygous and displayed minimal intra-lineage diversity indicative of even earlier origins than sequence-based estimates. Natural hybrid genotypes resembled typical meiotic F1 progeny, however, evidence for mitochondrial introgression, absence of haploid forms and previous experimental crosses indicate that sexual reproduction in T. cruzi may involve alternatives to canonical meiosis. Overall, the data support two independent hybridisation events between TcII and TcIII and a recent, rapid spread of the hybrid progeny in domestic transmission cycles concomitant with, or as a result of, disruption of natural transmission cycles by human activities

WFIRST Coronagraph Technology Requirements: Status Update and Systems Engineering Approach

The coronagraphic instrument (CGI) on the Wide-Field Infrared Survey Telescope (WFIRST) will demonstrate technologies and methods for high-contrast direct imaging and spectroscopy of exoplanet systems in reflected light, including polarimetry of circumstellar disks. The WFIRST management and CGI engineering and science investigation teams have developed requirements for the instrument, motivated by the objectives and technology development needs of potential future flagship exoplanet characterization missions such as the NASA Habitable Exoplanet Imaging Mission (HabEx) and the Large UV/Optical/IR Surveyor (LUVOIR). The requirements have been refined to support recommendations from the WFIRST Independent External Technical/Management/Cost Review (WIETR) that the WFIRST CGI be classified as a technology demonstration instrument instead of a science instrument. This paper provides a description of how the CGI requirements flow from the top of the overall WFIRST mission structure through the Level 2 requirements, where the focus here is on capturing the detailed context and rationales for the CGI Level 2 requirements. The WFIRST requirements flow starts with the top Program Level Requirements Appendix (PLRA), which contains both high-level mission objectives as well as the CGI-specific baseline technical and data requirements (BTR and BDR, respectively)... We also present the process and collaborative tools used in the L2 requirements development and management, including the collection and organization of science inputs, an open-source approach to managing the requirements database, and automating documentation. The tools created for the CGI L2 requirements have the potential to improve the design and planning of other projects, streamlining requirement management and maintenance. [Abstract Abbreviated]Comment: 16 pages, 4 figure

Inhibition of \u3cem\u3eRhizobium etli\u3c/em\u3e Polysaccharide Mutants by \u3cem\u3ePhaseolus vulgaris\u3c/em\u3e Root Compounds

Crude bean root extracts of Phaseolus vulgaris were tested for inhibition of the growth of several polysaccharide mutants of Rhizobium etli biovar phaseoli CE3. Mutants deficient only in exopolysaccharide and some mutants deficient only in the O-antigen of the lipopolysaccharide were no more sensitive than the wild-type strain to the extracts, whereas mutants defective in both lipopolysaccharide and exopolysaccharide were much more sensitive. The inhibitory activity was found at much higher levels in roots and nodules than in stems or leaves. Inoculation with either wild-type or polysaccharide-deficient R. etli did not appear to affect the level of activity. Sequential extractions of the crude root material with petroleum ether, ethyl acetate, methanol, and water partitioned inhibitory activity into each solvent except methanol. The major inhibitors in the petroleum ether and ethyl acetate extracts were purified by C18 high-performance liquid chromatography. These compounds all migrated very similarly in both liquid and thin-layer chromatography but were distinguished by their mass spectra. Absorbance spectra and fluorescence properties suggested that they were coumestans, one of which had the mass spectrum and nuclear magnetic resonances of coumestrol. These results are discussed with regard to the hypothesis that one role of rhizobial polysaccharides is to protect against plant toxins encountered during nodule development

The contribution of marine organics to the air quality of the western United States

The contribution of marine organic emissions to the air quality in coastal areas of the western United States is studied using the latest version of the US Environmental Protection Agency (EPA) regional-scale Community Multiscale Air Quality (CMAQv4.7) modeling system. Emissions of marine isoprene, monoterpenes, and primary organic matter (POM) from the ocean are implemented into the model to provide a comprehensive view of the connection between ocean biology and atmospheric chemistry and air pollution. Model simulations show that marine organics can increase the concentration of PM<sub>2.5</sub> by 0.1–0.3 μg m<sup>−3</sup> (up to 5%) in some coastal cities such as San Francisco, CA. This increase in the PM<sub>2.5</sub> concentration is primarily attributed to the POM emissions, with small contributions from the marine isoprene and monoterpenes. When marine organic emissions are included, organic carbon (OC) concentrations over the remote ocean are increased by up to 50% (25% in coastal areas), values consistent with recent observational findings. This study is the first to quantify the air quality impacts from marine POM and monoterpenes for the United States, and it highlights the need for inclusion of marine organic emissions in air quality models

Adolescent physical self-perceptions, sport/exercise and lifestyle physical activity

Purpose – Domain and sub-domain physical self-perceptions have been associated with adolescent moderate intensity physical activity although the association with different types of adolescent moderate intensity physical activity remains unclear. This study seeks to examine the relationship between personal self-perceptions and adolescent sport/exercise and lifestyle moderate intensity physical activity frequency. Design/methodology/approach – A total of 122, 13-to-14 year-old, English adolescents from Leeds, West Yorkshire (58 boys and 64 girls) had their personal self-perceptions, sport/exercise and lifestyle moderate intensity physical activity assessed. Findings – No significant positive relationships were found between boys' personal self-perceptions and lifestyle moderate intensity physical activity. However, a range of weak (r?=?0.34-0.42) but significant relationships (p?<?0.01) were found between personal self perceptions and boys' sport/exercise frequency. In contrast, only perceptions of strength competence were significantly related to girls' sport/exercise frequencies (r?=?0.28; p?<?0.05), while all personal self perceptions scales were significantly related to girls' lifestyle moderate intensity physical activity (r?=?0.26-0.32; p?<?0.05). Research limitations/implications – The use of correlation analyses by this study placed limitations on the extent to which cause-effect relationships were established. Furthermore, girls' sport/exercise was poorly distributed, which may have led to the non-significant relationship found between this activity type and personal self-perceptions. The presence of a significant relationship between these two variables should therefore not be discounted. Originality/value – This study seems to be the first to investigate and identify variations in the personal self-perceptions – moderate intensity physical activity relationship relative to activity type. Although more research is required, findings have implications for practitioners aiming to tailor physical activity interventions to this group and researchers aiming to match specific correlates to different types of adolescent physical activity

The Paradox of Compacts: final report to the Home Office on monitoring the impact of Compacts

The Compact is an important building block in achieving a better relationship between Government and the voluntary and community sector. We are fully committed to partnership working with the sector and increasing their role in civil society and in the delivery of public s e rvices. The Compact helps us to work better together, so that we can better meet the needs of communities

The oxidation of isothiocyanato - chromium (III) complexes by bromine in aqueous solution.

Thesis (M.A.)--Boston UniversityOver the past ten to fifteen years much work has been done on oxidation and reduction reactions of coordination complexes in aqueous solution. Relatively little attention has been devoted, however, to the study of reactions in which ligands of these complexes are oxidized or reduced. In the present work an investigation was carried out on the bromine oxidation of the isothiocyanatopentamiminechromium(III) ion and of tetraisothiocyanatodiamminechromate(III) ion. Werner (16) studied the bromine oxidation of ammonium reineckate, and after extensive treatment of the reaction solution isolated the green salt [Cr(NH3)2(Br)2(H2O)2]Br. In the present study, an attempt was made to establish the stoichiometry of the bromine oxidations of the Reineckate ion and the [Cr(NH3)5NCS]+2 ion. Work was done on the identification of the oxidation products and on correlation of these products with the observed stoichiometry. The oxidation of the Reineckate ion was carried out in both buffered solution, at a pH of 4.5-5, and acidic solution, with a pH of 1-2, in order to note any difference in the measured stoichiometries with the change in acidity. Measurements were also made to determine if dissociation of the complex preceded the initial oxidation step. [Cr(NH3)5NCS](ClO4)2 was prepared from [Cr(NH3)5Cl] by a procedure based on the method of Adamson and Wilkins (3). The [Cr(NH3)5Cl]Cl2 was prepared by the reduction of chromic ion to chromous ion by zinc in the presence of acid. The chromous ion by zinc in the presence of acid. The chromous ion was then oxidized by air in the presence of ammonium chloride in aqueous ammonia. This solution was treated with hot hydrochloric acid to obtain the internediate [Cr(NH3)5Cl]Cl2. The following procedure was used to determine the rate of consumption of bromine and extablish the stoichiometry of the reactant species. Definite volumes of solution containing complex ion and hydrochloric acid or acetate buffer were placed in one flask, and the same volumes of blank solution containing hydrochloric acid or buffer, but no complex, wwere placed in another flask. A certain volume of aqueous bromine was added to each flask, and after a certain selected time, the remaining bromine was quenched with protassium iodide. The liberated iodine was titrated with standard sodium thiosulfate solution using starch as an indicator. The stoichiometries (the moles of bromine consumed per mole of complex ion) were determined using this same method. The chromium content of each solution of complex was determined by destroying the complex in hot alkali, oxidizing the chromite ion solution to chromate ion by hot hydrogen peroxide, and measuring the absorbance of the resulting chromate solution at a wave length of 372 millimicrons. From the measurements made on the bromine oxidation of Reineckate ion, it appears that there is an initial rapid reaction followed by a slower consumption of bromine. From the available data concerning the oxidation of [Cr(NH3)5NCS]+2, there also appears to be an initial rapid consumption of bromine. Measurements did not indicate a slower consumption of bromine. Allowing the buffered oxidation of Reineckate ion by bromine to take place for 10 minutes, at a pH of 4.5-5, the observed stoichiometry was 14.2 moles of bromine per mole of Reineckate ion. In acidic solution, at a pH of 1-2, the apparent stoichiometry of the Reineckate ion oxidation was 14.0 moles of bromine per mole of Reineckate ion. The stoichiometry of the [Cr(NH3)5NCS]+2 ion oxidation, allowing the reaction to take place for 15 minutes, was 3.2 moles of bromine consumed per mole of complex ion. Sulfate ion and nitrate ion were both identified as products of the Reineckate ion oxidation. The cyanide ion and the ammonium ion were not detected and are thus ruled out as possible oxidation products. No suitable test was devised for the identification of carbon dioxide. More work should be done on the study of the slower secondary oxidation by bromine of Reineckate ion. The bromine oxidation of [Cr(NH3)5NCS]+2 should be investigated in more detail and perhaps a comparison of the oxidation rates of it and the Reineckate ion could be made where possible. A reaction apparatus should be designed which would trap any gaseous oxidation products formed and a correlation could be made between the reaction products formed during each reaction interval and the observed stoichiometries

Optimal classical-communication-assisted local model of n-qubit Greenberger-Horne-Zeilinger correlations

We present a model, motivated by the criterion of reality put forward by Einstein, Podolsky, and Rosen and supplemented by classical communication, which correctly reproduces the quantum-mechanical predictions for measurements of all products of Pauli operators on an n-qubit GHZ state (or ``cat state''). The n-2 bits employed by our model are shown to be optimal for the allowed set of measurements, demonstrating that the required communication overhead scales linearly with n. We formulate a connection between the generation of the local values utilized by our model and the stabilizer formalism, which leads us to conjecture that a generalization of this method will shed light on the content of the Gottesman-Knill theorem.Comment: New version - expanded and revised to address referee comment

Relapses of Plasmodium vivax infection usually result from activation of heterologous hypnozoites.

BACKGROUND: Relapses originating from hypnozoites are characteristic of Plasmodium vivax infections. Thus, reappearance of parasitemia after treatment can result from relapse, recrudescence, or reinfection. It has been assumed that parasites causing relapse would be a subset of the parasites that caused the primary infection. METHODS: Paired samples were collected before initiation of antimalarial treatment and at recurrence of parasitemia from 149 patients with vivax malaria in Thailand (n=36), where reinfection could be excluded, and during field studies in Myanmar (n=75) and India (n=38). RESULTS: Combined genetic data from 2 genotyping approaches showed that novel P. vivax populations were present in the majority of patients with recurrent infection (107 [72%] of 149 patients overall [78% of patients in Thailand, 75% of patients in Myanmar {Burma}, and 63% of patients in India]). In 61% of the Thai and Burmese patients and in 55% of the Indian patients, the recurrent infections contained none of the parasite genotypes that caused the acute infection. CONCLUSIONS: The P. vivax populations emerging from hypnozoites commonly differ from the populations that caused the acute episode. Activation of heterologous hypnozoite populations is the most common cause of first relapse in patients with vivax malaria