1,050 research outputs found

    Identification of zeta-carotene desaturase genes from durum wheat

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    Non-Peer ReviewedYellow pigment is an important quality trait in durum wheat (Triticum turgidum L. var durum). Few genes within the pathway responsible for carotenoid biosynthesis have yet to been identified in durum wheat. Zeta-carotene desaturase (ZDS) is an enzyme involved in carotenoid biosynthesis, and variation in the gene(s) coding for ZDS may partially explain the variation observed in endosperm color among durum wheat cultivars. For this study, a PCR strategy was used to clone and sequence greater than 1200 bp of the Zds genes from durum cultivars Kofa (high pigment) and W9262-D063 (medium pigment). Comparison of partial nucleotide sequences indicated the presence of four Zds genes which we temporarily designated as tdZds1, tdZds2, tdZds3, and tdZds4. Since durum wheat is a tetraploid, the presence of four genes suggests that the Zds gene may in fact be duplicated in the durum wheat genome, with two sets of homeologous genes. However, we have only obtained single clones of Zds2 and Zds4 from each of the two parents, and these results will need to be confirmed. However, we are currently in the process of mapping Zds1 and Zds3 to determine their role in the expression of yellow pigment concentration in durum wheat

    Immune compromise in HIV-1/HTLV-1 coinfection with paradoxical resolution of CD4 lymphocytosis during antiretroviral therapy: a case report

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    Human immunodeficiency virus type-1 (HIV-1) and human T lymphotropic virus type-1 (HTLV-1) infections have complex effects on adaptive immunity, with specific tropism for, but contrasting effects on, CD4 T lymphocytes: depletion with HIV-1, proliferation with HTLV-1. Impaired T lymphocyte function occurs early in HIV-1 infection but opportunistic infections (OIs) rarely occur in the absence of CD4 lymphopenia. In the unusual case where a HIV-1 infected individual with a high CD4 count presents with recurrent OIs, a clinician is faced with the possibility of a second underlying comorbidity. We present a case of pseudo-adult T cell leukemia/lymphoma (ATLL) in HIV-1/HTLV-1 coinfection where the individual fulfilled Shimoyama criteria for chronic ATLL and had pulmonary Mycobacterium kansasii, despite a high CD4 lymphocyte count. However, there was no evidence of clonal T-cell proliferation by T-cell receptor gene rearrangement studies nor of monoclonal HTLV-1 integration by high-throughput sequencing. Mutually beneficial interplay between HIV-1 and HTLV-1, maintaining high level HIV-1 and HTLV-1 viremia and proliferation of poorly functional CD4 cells despite chronicity of infection is a postulated mechanism. Despite good microbiological response to antimycobacterial therapy, the patient remained systemically unwell with refractory anemia. Subsequent initiation of combined antiretroviral therapy led to paradoxical resolution of CD4 T lymphocytosis as well as HIV-1 viral suppression and decreased HTLV-1 proviral load. This is proposed to be the result of attenuation of immune activation post-HIV virological control. This case illustrates the importance of screening for HTLV-1 in HIV-1 patients with appropriate clinical presentation and epidemiological risk factors and explores mechanisms for the complex interactions on HIV-1/HTLV-1 adaptive immunity

    Detection and evaluation of residual effects by defeated stripe rust resistance genes (Yr genes) in common wheat against virulent Puccinia striiformis f. sp. tritici isolates

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    Non-Peer ReviewedRace-specific stripe rust resistance genes (Yr genes) have been deployed into wheat cultivars against stripe rust caused by Puccinia striiformis f. sp. tritici Eriks. (Pst); however, the resistance has been quickly broken down only years after its introduction. Near isogenic lines (NILs) with defeated Yr genes were used in this study to evaluate partial non-race-specific resistance of the residual effect as possible durable resistance. The parental NILs with single Yr genes (Yr10, Yr26, Yr32) with Avocet background, F5 NILs with two Yr genes in the combinations of Yr26/Yr10, Yr32/Yr10 and Yr32/Yr26 and susceptible cultivar Avocet were inoculated with one of three Pst inoculums (W020, W049, T034+W052) virulent to all three Yr genes and infection type (IT), infection area (IA) and latent period (LP) were recorded. The same NILs were tested in stripe rust nurseries at Saskatoon, SK and Lethbridge, AB in 2018 and disease incidence and severity were recorded. The range of IT tended to be lower in NILs with Yr32/Yr10 and Yr32/Yr26 genes only with T034/W052. With different isolates, IA was reduced more often in the NILs with Yr32/Yr10 and Yr32/Yr26 genes than with Yr26/Yr10. The extension of LP correlated with reduction of IA. In disease nurseries, the natural Pst population appeared to be avirulent to Yr10 and Yr26 at both locations and the results were inconclusive. These results from growth chamber experiments suggest that residual effect by defeated Yr genes possibly exists in certain combinations

    Matrix Element Distribution as a Signature of Entanglement Generation

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    We explore connections between an operator's matrix element distribution and its entanglement generation. Operators with matrix element distributions similar to those of random matrices generate states of high multi-partite entanglement. This occurs even when other statistical properties of the operators do not conincide with random matrices. Similarly, operators with some statistical properties of random matrices may not exhibit random matrix element distributions and will not produce states with high levels of multi-partite entanglement. Finally, we show that operators with similar matrix element distributions generate similar amounts of entanglement.Comment: 7 pages, 6 figures, to be published PRA, partially supersedes quant-ph/0405053, expands quant-ph/050211

    Conditional q-Entropies and Quantum Separability: A Numerical Exploration

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    We revisit the relationship between quantum separability and the sign of the relative q-entropies of composite quantum systems. The q-entropies depend on the density matrix eigenvalues p_i through the quantity omega_q = sum_i p_i^q. Renyi's and Tsallis' measures constitute particular instances of these entropies. We perform a systematic numerical survey of the space of mixed states of two-qubit systems in order to determine, as a function of the degree of mixture, and for different values of the entropic parameter q, the volume in state space occupied by those states characterized by positive values of the relative entropy. Similar calculations are performed for qubit-qutrit systems and for composite systems described by Hilbert spaces of larger dimensionality. We pay particular attention to the limit case q --> infinity. Our numerical results indicate that, as the dimensionalities of both subsystems increase, composite quantum systems tend, as far as their relative q-entropies are concerned, to behave in a classical way

    The UK register of HIV seroconverters: Methods and analytical issues

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    A Register of HIV-infected persons who have had a negative antibody test within 3 years of their first antibody positive test (seroconverters) is being set up in the UK to monitor the distribution of times from HIV seroconversion to AIDS (the incubation period) and to death. It will also provide a national resource for use by those designing studies in this group of individuals. Clinicians caring for HIV-positive persons in Genito-Urinary Medicine, Infectious Disease and other departments throughout the UK were asked to participate by providing information on eligible subjects. Most laboratories undertaking HIV antibody testing were also contacted and asked to provide the name of the attending clinician for all seroconverters identified through the HIV laboratory reporting systems of the PHLS Communicable Disease Surveillance Centre (CDSC) and the Scottish Centre for Infection and Environmental Health (SCIEH) and for any other seroconverters known to them but not identified by CDSC or SCIEH. Data items sought for the Register include: sex, ethnic group, probable route of HIV transmission, annual CD4 counts, details of therapy and prophylaxis prescribed, AIDS-defining events and vital status. Follow up information is collected annually. Wherever possible, all seroconverters known to a clinic have been identified, whether currently alive or dead, either from clinic records or laboratory reporting or both. The objective is to establish and update a complete register of seroconverters on a long-term basis to provide reliable estimates of the incubation period on which future projections of AIDS cases in the UK can be made

    Entanglement Distribution and Entangling Power of Quantum Gates

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    Quantum gates, that play a fundamental role in quantum computation and other quantum information processes, are unitary evolution operators U^\hat U that act on a composite system changing its entanglement. In the present contribution we study some aspects of these entanglement changes. By recourse of a Monte Carlo procedure, we compute the so called "entangling power" for several paradigmatic quantum gates and discuss results concerning the action of the CNOT gate. We pay special attention to the distribution of entanglement among the several parties involved

    Synthetic SXR diagnostic using GEM detectors on WEST: development in the prospect of tungsten monitoring

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    International audienceWEST (Tungsten Environment in Steady-State Tokamak) will be operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of highly ionized impurities like tungsten (W) sputtered from Plasma Facing Components (PFC) into the plasma core is a critical issue since even small impurity concentrations below 10-4 degrade significantly plasma performances and can lead to radiative collapse. In the plasma core, tungsten emission is dominant in the Soft X-ray (SXR) range 0.1 keV – 15 keV with complex contributions from line transition, radiative recombination and Bremsstrahlung emission.This paper presents the recent development of a synthetic SXR diagnostic using GEM (Gas Electron Multiplier) detectors. This diagnostic will be used on WEST for W transport studies and will be equipped with two new GEM based poloidal cameras allowing 2D tomographic reconstructions with spectral resolution in energy bands. Thus once GEM response to plasma emissivity is characterized thanks to synthetic diagnostic, it offers new possibilities to disentangle the different SXR contributions in harsh fusion environments like e.g. WEST or ITER with respect to conventional semiconductor diodes working in current mode. Emitted SXR spectrum from the plasma is modelled thanks to ADAS database from given WEST scenario. The synthetic diagnostic includes Lines of Sight (LoS) etendues of the two cameras as well as probability of photoabsorption through filters, photoionization in the detection gas mixture (Ar-CO2), and transport of electron avalanches in the gas through GEM foils as computed with Magboltz. Local SXR emissivity is then retrieved from tomographic inversion using a Minimum Fisher Information (MFI) algorithm
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