371 research outputs found

    Use of Wild Species in Developing Varieties

    Get PDF
    The familiar plant known as tobacco has the more technical name of Nicotiana tabacum L. It belongs to a family of plants called the Solanaceae or Nightshade family. This family includes many familiar species besides tobacco: tomato, potato, bitter sweet, horse-nettle, ground-cherry, jimsonweed, henbane, and petunia, to mention only a few. In addition to these more distant relatives of tobacco, there are approximately 65 Nicotiana species. Morphologically, the Nicotiana species are very diverse, ranging from those resembling tobacco to the extreme types that look more like cabbage. The species are widespread geographically, with a particularly large concentration in South and Central America

    KYRT1, a Disarmed Version of a Highly Tumorigenic \u3cem\u3eAgrobacterium Tumefaciens\u3c/em\u3e Strain Identified as Chry5

    Get PDF
    Disarmed A. tumefaciencs strain KYRT1, derived from a highly tumorigenic strain identified as A. tumefaciens strain Chry5. Disarming is accomplished by inactivation of plasmid pTiChry5 T-DNA sequences by, for example, deletion of sequences comprising the T-DNA right border. Methods of making transgenic plants using the novel A. tumefaciens strains are also provided

    Control of Black Root Rot in Dark Tobacco

    Get PDF
    Reports of the increasing prevalence of black root rot in the areas where dark tobacco types are grown has triggered an accelerated effort from the tobacco research staff to develop and release additional varieties with high resistance to this disease. The high level of resistance to black root rot found in Nicotiana debneyi (an Australian species) is being used as the source of resistance in the breeding program

    Use of Bacterial Acetate Kinase and Their Genes for Protection of Plants Against Different Pathogens

    Get PDF
    An isolated gene fragment that encodes for acetate kinase, which confers disease resistance in plants is disclosed. The gene can be cloned into an expression vector to produce a recombinant DNA expression system suitable for insertion into cells to form a transgenic plant transformed with the gene fragment. A method for conferring disease resistance in plants that consists of growing plant host cells transformed with the expression system and expressing the gene conferring disease resistance to impart such resistance to host cells is also disclosed

    Transformation, Somatic Embryogenesis and Whole Plant Regeneration Method for Glycine Species

    Get PDF
    A method for somatic embryogenesis of soybean, (Glycine max), Glycine soja and other Glycine species is provided using immature cotyledon tissue, preferably with the embryonic axis removed, comprising culturing said tissue on a medium containing auxin, preferably NAA at a concentration of at least about 15 mg/l. A further method for such somatic embryogenesis is provided wherein the culture medium contains a synergistically acting lowered carbohydrate and auxin concentration. Particularly embryogenic cells of such tissue are identified and improved maceration methods for contacting such cells with regeneration and transformation media are disclosed. Methods for transforming somatic tissue from soybean and other Glycine species are also provided. Whole, fertile, transformed plants are obtained

    The electrical structure of the central Pacific upper mantle constrained by the NoMelt experiment

    Get PDF
    Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 16 (2015): 1115–1132, doi:10.1002/2014GC005709.The NoMelt experiment imaged the mantle beneath 70 Ma Pacific seafloor with the aim of understanding the transition from the lithosphere to the underlying convecting asthenosphere. Seafloor magnetotelluric data from four stations were analyzed using 2-D regularized inverse modeling. The preferred electrical model for the region contains an 80 km thick resistive (>103 Ωm) lithosphere with a less resistive (∼50 Ωm) underlying asthenosphere. The preferred model is isotropic and lacks a highly conductive (≤10 Ωm) layer under the resistive lithosphere that would be indicative of partial melt. We first examine temperature profiles that are consistent with the observed conductivity profile. Our profile is consistent with a mantle adiabat ranging from 0.3 to 0.5°C/km. A choice of the higher adiabatic gradient means that the observed conductivity can be explained solely by temperature. In contrast, a 0.3°C/km adiabat requires an additional mechanism to explain the observed conductivity profile. Of the plausible mechanisms, H2O, in the form of hydrogen dissolved in olivine, is the most likely explanation for this additional conductivity. Our profile is consistent with a mostly dry lithosphere to 80 km depth, with bulk H2O contents increasing to between 25 and 400 ppm by weight in the asthenosphere with specific values dependent on the choice of laboratory data set of hydrous olivine conductivity and the value of mantle oxygen fugacity. The estimated H2O contents support the theory that the rheological lithosphere is a result of dehydration during melting at a mid-ocean ridge with the asthenosphere remaining partially hydrated and weakened as a result.Funding for the NoMELT experiment was provided by the National Science Foundation through the following grant numbers: OCE-0927172, OCE-0928270, OCE-1459649, and OCE-0928663.2015-10-1

    Neuronal guidance molecule netrin-1 attenuates inflammatory cell trafficking during acute experimental colitis

    Get PDF
    Background: Inflammatory bowel diseases, encompassing Crohn’s disease and ulcerative colitis, are characterised by persistent leucocyte tissue infiltration leading to perpetuation of an inappropriate inflammatory cascade. The neuronal guidance molecule netrin-1 has recently been implicated in the orchestration of leucocyte trafficking during acute inflammation. We therefore hypothesised that netrin-1 could modulate leucocyte infiltration and disease activity in a model of inflammatory bowel disease. Design: DSS-colitis was performed in mice with partial genetic netrin-1 deficiency (Ntn-1+/- mice) or wild-type mice treated with exogenous netrin-1 via osmotic pump to examine the role of endogenous and therapeutically administered netrin-1. These studies were supported by in vitro models of transepithelial migration and intestinal epithelial barrier function. Results: Consistent with our hypothesis, we observed induction of netrin-1 during intestinal inflammation in vitro or in mice exposed to experimental colitis. Moreover, mice with partial netrin-1 deficiency demonstrated an exacerbated course of DSS-colitis compared to littermate controls, with enhanced weight loss and colonic shortening. Conversely, mice treated with exogenous mouse netrin-1 experienced attenuated disease severity. Importantly, permeability studies and quantitative assessment of apoptosis reveal that netrin-1 signalling events do not alter mucosal permeability or intestinal epithelial cell apoptosis. In vivo studies of leucocyte transmigration demonstrate suppression of neutrophil trafficking as a key function mediated by endogenous or exogenously administered netrin-1. Finally, genetic studies implicate the A2B adenosine receptor in netrin-1-mediated protection during DSS-colitis. Conclusions: The present study identifies a previously unrecognised role for netrin-1 in attenuating experimental colitis through limitation of neutrophil trafficking

    The ideal job-seeker norm: unemployment and marital privileges in the professional middle-class

    Get PDF
    Objective: To understand how heterosexual US married parents interpret and respond to a spouse's unemployment and subsequent job-searching. Background: The pervasiveness of employment uncertainty, and unemployment, may propel families to embrace gender egalitarian norms. Quantitative research finds that this possibility is not borne out. Qualitative research has sought to illuminate mechanisms as to how gender norms persist even during a time that is optimal for dismantling them, but these mechanisms remain unclear. Method: Seventy-two in-depth interviews were conducted with a nonrandom sample of heterosexual, professional, dual-earner, married, unemployed women, men, and their spouses in the United States. Follow-up interviews were conducted with 35 participants. Intensive family observations were conducted with four families, two of unemployed men, and two of unemployed women. Results: Unemployed women, men, and spouses acknowledge that a set of time-intensive activities are key for reemployment (the ideal job-seeker norm). Couples with unemployed men direct resources such as time, space, and even money to facilitate unemployed men's compliance with the ideal job-seeker norm. Couples downplay the importance of women's reemployment and do not direct similar resources to help unemployed women job-search. Conclusion: Couples preserve a traditional gender status quo, often in defiance of material realities, by actively maintaining men's position at the helm of paid work and women's at unpaid work. Implications: Linking unemployment and job-seeking with the institution of heterosexual marriage reveals novel insights into social and marital processes shaping job-seeking

    Transplantation in Remission Improves the Disease-Free Survival of Patients with Advanced Myelodysplastic Syndromes Treated with Myeloablative T Cell-Depleted Stem Cell Transplants from HLA-Identical Siblings

    Get PDF
    AbstractFrom 1985 to 2004, 49 patients with advanced myelodysplastic syndromes (MDS) (≥5% blasts) or acute myeloid leukemia (AML) transformed from MDS underwent T cell depleted bone marrow or peripheral blood hematopoietic stem cell transplantation (HSCT) from HLA-identical siblings following conditioning with a myeloablative regimen that included total body irradiation (44 patients) or busulfan (5 patients). Thirty-six patients received chemotherapy (3 low dose and 33 induction doses) before conditioning, and 13 patients did not receive any chemotherapy. Prior to transplantation, 22 of the 36 treated patients were in hematologic remission; 4 were in a second refractory cytopenia phase (26 responders); 8 had failed to achieve remission; and 2 of the responders had progression or relapse of their MDS (10 failures). No post-transplantation pharmacologic prophylaxis for graft-versus-host disease (GVHD) was given. The median age was 48 yrs (range 13-61). Forty-five of the 49 patients engrafted; 2 had primary graft failure; and 2 died before engraftment. Only 3 patients developed acute GVHD (aGVHD) (grades I and III) and 1 chronic GVHD (cGVHD). At 3 yrs post-transplantation, the overall survival (OS) was 54% in the responders; 31% in the untreated group; and 0% in the failure group (P=.0004). The disease free survival (DFS) was 50%, 15% and 0% in each group respectively (P=.0008). In multivariate analysis, disease status before cytoreduction remained highly correlated with DFS (P<.001). The cumulative incidence (CI) of relapse at 2-yrs post-transplantation for the responders was 23%; for the untreated group was 38%; and for the failures was 50%. The CI of non-relapse mortality at 2-yrs post-transplantation, for the responders was 23%; for the untreated group was 38%; and for the failures was 40%. All survivors achieved a Karnofsky Performance Status (KPS) of ≥90. These results indicate that patients with advanced MDS who achieve and remain in remission or a second refractory cytopenia phase with chemotherapy before conditioning can achieve successful long-term remissions following a myeloablative T cell depleted allogeneic HSCT

    Viral population estimation using pyrosequencing

    Get PDF
    The diversity of virus populations within single infected hosts presents a major difficulty for the natural immune response as well as for vaccine design and antiviral drug therapy. Recently developed pyrophosphate based sequencing technologies (pyrosequencing) can be used for quantifying this diversity by ultra-deep sequencing of virus samples. We present computational methods for the analysis of such sequence data and apply these techniques to pyrosequencing data obtained from HIV populations within patients harboring drug resistant virus strains. Our main result is the estimation of the population structure of the sample from the pyrosequencing reads. This inference is based on a statistical approach to error correction, followed by a combinatorial algorithm for constructing a minimal set of haplotypes that explain the data. Using this set of explaining haplotypes, we apply a statistical model to infer the frequencies of the haplotypes in the population via an EM algorithm. We demonstrate that pyrosequencing reads allow for effective population reconstruction by extensive simulations and by comparison to 165 sequences obtained directly from clonal sequencing of four independent, diverse HIV populations. Thus, pyrosequencing can be used for cost-effective estimation of the structure of virus populations, promising new insights into viral evolutionary dynamics and disease control strategies.Comment: 23 pages, 13 figure
    corecore