1,082 research outputs found
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A universal primer for isolation of fragments of a gene encoding phytoene desaturase for use in virus-induced gene silencing (VIGS) studies
We have been using Virus-Induced Gene Silencing (VIGS) to test the function of genes that are candidates for involvement in floral senescence. Although VIGS is a powerful tool for assaying the effects of gene silencing in plants, relatively few taxa have been studied using this approach, and most that have are in the Solanaceae. We typically use silencing of phytoene desaturase (PDS) in preliminary tests of the feasibility of using VIGS. Silencing this gene, whose product is involved in carotene biosynthesis, results in a characteristic photobleaching phenotype in the leaves. We have found that efficient silencing requires the use of fragments that are more than 90% homologous to the target gene. To simplify testing the effectiveness of VIGS in a range of species, we designed a set of universal primers to a region of the PDS gene that is highly conserved among species, and that therefore allows an investigator to isolate a fragment of the homologous PDS gene from the species of interest. We report the sequences of these primers and the results of VIGS experiments in horticultural species from the Asteraceae, Leguminosae, Balsaminaceae and Solanaceae
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Perception of bitterness, sweetness and liking of different genotypes of lettuce
Lettuce is an important leafy vegetable, consumed across the world, containing bitter sesquiterpenoid lactone (SL) compounds that may negatively affect consumer acceptance and consumption. We assessed liking of samples with differing absolute abundance and different ratios of bitter:sweet compounds by analysing recombinant inbred lines (RILs) from an interspecific lettuce mapping population derived from a cross between a wild (L. serriola acc. UC96US23) and domesticated lettuce, (L. sativa, cv. Salinas). We found that the ratio of bitter:sweet compounds was a key determinant of bitterness perception and liking. We were able to demonstrate that SLs such as 8-deoxylactucin-15-sulphate contribute most strongly to bitterness perception, whilst 15-p-hydroxylphenylacetyllactucin-8-sulphate does not contribute to bitter taste. Glucose was the sugar most highly correlated with sweetness perception. There is a genetic basis to the biochemical composition of lettuce. This information will be useful in lettuce breeding programmes in order to produce leaves with more favourable taste profiles
Character sums for primitive root densities
It follows from the work of Artin and Hooley that, under assumption of the
generalized Riemann hypothesis, the density of the set of primes for which
a given non-zero rational number is a primitive root modulo can be
written as an infinite product of local factors
reflecting the degree of the splitting field of at the primes ,
multiplied by a somewhat complicated factor that corrects for the
`entanglement' of these splitting fields. We show how the correction factors
arising in Artin's original primitive root problem and some of its
generalizations can be interpreted as character sums describing the nature of
the entanglement. The resulting description in terms of local contributions is
so transparent that it greatly facilitates explicit computations, and naturally
leads to non-vanishing criteria for the correction factors. The method not only
applies in the setting of Galois representations of the multiplicative group
underlying Artin's conjecture, but also in the GL-setting arising for
elliptic curves. As an application, we compute the density of the set of primes
of cyclic reduction for Serre curves.Comment: 23 pages. This version is to appear in the Mathematical Proceedings
of the Cambridge Philosophical Societ
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Utah Southwest Regional Geothermal Development Operations Research Project. Appendix 10 of regional operations research program for development of geothermal energy in the Southeast United States. Final technical report, June 1977--August 1978
The Southwest Regional Geothermal Operations/Research project was initiated to investigate geothermal development in the five states within the region: Arizona, Colorado, Nevada, New Mexico, and Utah. Although the region changed during the first year to include Idaho, Montana, North Dakota, South Dakota, and Wyoming, the project objectives and procedures remained unchanged. The project was funded by the DOE/DGE and the Four Corners Regional Commission with participation by the New Mexico Energy Resources Board. The study was coordinated by the New Mexico Energy Institute at New Mexico State University, acting through a 'Core Team'. A 'state' team, assigned by the states, conducted the project within each state. This report details most of the findings of the first year's efforts by the Utah Operations/Research team. It is a conscientious effort to report the findings and activities of the Utah team, either explicitly or by reference. The results are neither comprehensive nor final, and should be regarded as preliminary efforts to much of what the Operations/Research project was envisioned to accomplish. In some cases the report is probably too detailed, in other cases too vague; hopefully, however, the material in the report, combined with the Appendices, will be able to serve as source material for others interested in geothermal development in Utah
For the time being
This paper is a reflection on my journey away from painting and my recent effort to broaden my understanding of internal and external experience by exploring language and the material world. This journey has led me a few steps closer to finding my voice as an artist. It loosed the threads of thought, multiple and variable, that comprise this thesis body of work
Effects of interleukin-3 on myelosuppression induced by chemotherapy for ovarian cancer and small cell undifferentiated tumours.
Two clinical studies were undertaken to study the toxicity profile and effects of interleukin-3 (rhIL-3) on chemotherapy-induced myelosuppression. Fifteen patients with recurrent ovarian carcinoma were treated with high dose carboplatin (800 mg m-2). All patients received 5.0 micrograms/kg/d rhIL-3 subcutaneously but timing and duration of rhIL-3 treatment differed. Constitutional symptoms were the major toxicity and in addition to the carboplatin-induced nausea and vomiting the combination was poorly tolerated. In 5/15 patients receiving high dose carboplatin rhIL-3 administration was discontinued due to nephrotoxicity (2 x), hypotension, severe malaise and bone pain. In this study, rhIL-3 ameliorated chemotherapy-induced neutropenia as well as thrombocytopenia and reduced the requirement for platelet transfusions in the second cycle of chemotherapy. However, rhIL-3 failed to prevent cumulative platelet toxicity. In the second study 12 patients with small cell undifferentiated cancers were treated with carboplatin, etoposide and ifosfamide. Three dose levels of rhIL-3 were explored (0.125, 5.0 and 7.5 micrograms/kg/d). In this study, toxicity of the treatment was mild, however, no beneficial haematologic effects of rhIL-3 could be demonstrated. In conclusion, the haematological effects of rhIL-3 were modest and dependent on the chemotherapeutic regimen, timing and duration of rhIL-3 treatment (in relation to the expected nadir). In general rhIL-3-induced toxicity was mild, but combination with high dose carboplatin could be hazardous if rhIL-3 is initiated at 24 h after the cytostatic agent
Prognostic factors in high and intermediate grade non-Hodgkin's lymphoma.
An analysis of prognostic factors has been performed on 260 patients with high and intermediate grade non-Hodgkin's lymphoma (NHL) treated over an 11-year period between 1975 and 1986. The overall 5-year survival rate was 50% with a median follow-up of 72 months. Over 20 clinical, radiological and laboratory parameters have been studied, including variables reported to be important indicators of prognosis in previous series, and these variables have been subjected to univariate and multivariate analysis. Attainment of complete remission (CR) was the most important predictor of overall survival, low serum lactate dehydrogenase (LDH), limited stage disease and a high serum albumin were also independently associated with prolonged survival in multivariate analysis. After removing remission status from the model, Ann Arbor clinical stage became the most significant pre-treatment prognostic indicator. Sixty-five per cent of patients achieved CR, and a discriminant analysis showed that failure to attain CR was associated with advanced stage disease, constitutional symptoms, increasing patient age, a low serum albumin and the presence of bulk disease. Advanced clinical stage and an elevated serum LDH predicted independently for a poor relapse-free survival, and reduced overall survival following CR. There was no significant correlation between histological subtype in the Kiel classification and prognosis. This study confirms the prognostic significance of remission status and Ann Arbor clinical stage, and illustrates additional factors including serum levels of albumin and LDH, which serve to enhance the pre-treatment prognostic evaluation of patients with unfavourable histology NHL
A pilot study to evaluate the effects of C1 esterase inhibitor on the toxicity of high-dose interleukin 2.
In a pilot study six patients received 4 days' treatment with interleukin 2 (IL-2) [cumulative dose (CD) 264 +/- 26 x 10(6) IU m-2] and C1 esterase inhibitor (C1-INH) (loading dose 2,000 U, followed by 500-1,000 U twice daily). Toxicity was compared with that in patients given 4 days' treatment with standard (CD 66 +/- 12 x 10(6) IU m-2) or escalating-dose (CD 99 +/- 8 x 10(6) IU m-2) IL-2. IL-2-induced hypotension was equivalent and complement activation was less after IL-2 + C1-INH (C3a = 10.5 +/- 3.2 nmol l-1) than following standard (14.1 +/- 8.4 nmol l-1) or escalating-dose (18.3 +/- 2.9 nmol l-1) IL-2. This study demonstrates that C1-INH administration during IL-2 treatment is safe and warrants further study to evaluate its ability to ameliorate IL-2-induced toxicity
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