1,637 research outputs found
Searching for Clusters of Galaxies with SUMSS
Statistical overdensities of radio sources in the NRAO VLA Sky Survey (NVSS) catalogue have proven to be signposts to high-redshift clusters of galaxies. A similar search for overdensities has been carried out in the Sydney University Molonglo Sky Survey (SUMSS), which is closely matched in resolution and frequency to the NVSS. Sixty potential southern-hemisphere clusters have been found in SUMSS
Mathematical modelling of tissue-engineering angiogenesis
We present a mathematical model for the vascularisation of a porous scaffold following implantation in vivo. The model is given as a set of coupled non-linear ordinary differential equations (ODEs) which describe the evolution in time of the amounts of the different tissue constituents inside the scaffold. Bifurcation analyses reveal how the extent of scaffold vascularisation changes as a function of the parameter values. For example, it is shown how the loss of seeded cells arising from slow infiltration of vascular tissue can be overcome using a prevascularisation strategy consisting of seeding the scaffold with vascular cells. Using certain assumptions it is shown how the system can be simplified to one which is partially tractable and for which some analysis is given. Limited comparison is also given of the model solutions with experimental data from the chick chorioallantoic membrane (CAM) assay
Power requirements for electron cyclotron current drive and ion cyclotron resonance heating for sawtooth control in ITER
13MW of electron cyclotron current drive (ECCD) power deposited inside the q
= 1 surface is likely to reduce the sawtooth period in ITER baseline scenario
below the level empirically predicted to trigger neo-classical tearing modes
(NTMs). However, since the ECCD control scheme is solely predicated upon
changing the local magnetic shear, it is prudent to plan to use a complementary
scheme which directly decreases the potential energy of the kink mode in order
to reduce the sawtooth period. In the event that the natural sawtooth period is
longer than expected, due to enhanced alpha particle stabilisation for
instance, this ancillary sawtooth control can be provided from > 10MW of ion
cyclotron resonance heating (ICRH) power with a resonance just inside the q = 1
surface. Both ECCD and ICRH control schemes would benefit greatly from active
feedback of the deposition with respect to the rational surface. If the q = 1
surface can be maintained closer to the magnetic axis, the efficacy of ECCD and
ICRH schemes significantly increases, the negative effect on the fusion gain is
reduced, and off-axis negative-ion neutral beam injection (NNBI) can also be
considered for sawtooth control. Consequently, schemes to reduce the q = 1
radius are highly desirable, such as early heating to delay the current
penetration and, of course, active sawtooth destabilisation to mediate small
frequent sawteeth and retain a small q = 1 radius.Comment: 29 pages, 16 figure
3D chemical characterization of frozen hydrated hydrogels using ToF-SIMS with argon cluster sputter depth profiling
Hydrogels have been used extensively in bioengineering as artificial cell culture supports. Investigation of the interrelationship between cellular response to the hydrogel and its chemistry ideally requires methods that allow characterization without labels and can map species in three dimensional to follow biomolecules adsorbed to, and absorbed into, the open structure before and during culture. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has the potential to be utilized for through thickness characterization of hydrogels. The authors have established a simple sample preparation procedure to successfully achieve analysis of frozen hydrated hydrogels using ToF-SIMS without the need for dry glove box entry equipment. They demonstrate this on a poly(2-hydroxyethyl methacrylate) (pHEMA) film where a model protein (lysozyme) is incorporated using two methods to demonstrate how protein distribution can be determined. A comparison of lysozyme incorporation is made between the situation where the protein is present in a polymer dip coating solution and where lysozyme is in an aqueous medium in which the film is incubated. It is shown that protonated water clusters H(H2O)nþ where n ¼ 5–11 that are indicative of ice are detected through the entire thickness of the pHEMA. The lysozyme distribution through the pHEMA hydrogel films can be determined using the intensity of a characteristic amino acid secondary ion fragment
Research Notes : Inheritance of presence/absence of flavonoid compounds in soybean seedcoats
In soybean plants carrying the gene T and having black or brown pigmentation of seed coats, there are numerous compounds that can be detected by thin layer chromatography (TLC). There are four spots (A, B, C and D) that appear to be related; they are yellow-orange under visible light and they fluoresce yellow-orange (duller than quercetin) under UV light after spray-ing with flavone reagent. Phenotypic positions of A and D on 2-way plates are given in Table 1. A is present in all material tested, but D varies in presence/absence (B and C also vary but have not been studied)
Research notes: Soybean parental lines
Seed of five improved breeding lines (Table 1) is available upon request for use in crosses or experimental work. Disease reactions are given in Table 2 and physiological attributes in Table 3. The lines are somewhat improved over the unadapted parents; however, only OX610I has been yield tested
Research Notes : Genetics of black pigmentation of soybean seedcoats/hila
Gene T is involved in black pigmentation and w1 in the presence of t is involved in imperfect black pigmentation (Bernard and Weiss, 1973). Tis a phenolase gene resulting in quercetin formation and brown pubescence (Buttery and Buzzell, 1973); W is a flower and hypocotyl-color gene (Hartwig and Hinson, 1962). Thin layer chromatography shows two major \u27spots\u27 involved in black pigmentation of soybean seed coats
Prognostic significance of endogenous adhesion/growth-regulatory lectins in lung cancer
Objective: To determine the expression of endogenous adhesion/growth-regulatory lectins and their binding sites using labeled tissue lectins as well as the binding profile of hyaluronic acid as an approach to define new prognostic markers. Methods: Sections of paraffin-embedded histological material of 481 lungs from lung tumor patients following radical lung excision processed by a routine immunohistochemical method (avidin-biotin labeling, DAB chromogen). Specific antibodies against galectins-1 and - 3 and the heparin-binding lectin were tested. Staining by labeled galectins and hyaluronic acid was similarly visualized by a routine protocol. After semiquantitative assessment of staining, the results were compared with the pT and pN stages and the histological type. Survival was calculated by univariate and multivariate methods. Results: Binding of galectin-1 and its expression tended to increase, whereas the parameters for galectin-3 decreased in advanced pT and pN stages at a statistically significant level. The number of positive cases was considerably smaller among the cases with small cell lung cancer than in the group with non-small-cell lung cancer, among which adenocarcinomas figured prominently with the exception of galectin-1 expression. Kaplan-Meier computations revealed that the survival rate of patients with galectin-3-binding or galectin-1-expressing tumors was significantly poorer than that of the negative cases. In the multivariate calculations of survival lymph node metastases ( p < 0.0001), histological type ( p = 0.003), galectin-3-binding capacity ( p = 0.01), galectin-3 expression ( p = 0.03) and pT status ( p = 0.003) proved to be independent prognostic factors, not correlated with the pN stage. Conclusion: The expression and the capacity to bind the adhesion/growth regulatory galectin-3 is defined as an unfavorable prognostic factor not correlated with the pTN stage. Copyright (C) 2005 S. Karger AG, Basel
Research Notes : Flavonol classes of cultivars in Maturity Groups 00-IV
Since the complementary action of Fg1 and Fg3 in producing kaempferol 2G-glucosyl-gentiobioside (Buttery and Buzzell, 1975) is associated with deleterious effects on chlorophyll concentration, photosynthetic rate and yield (Buttery and Buzzell, 1976), the bringing together of these two genes in crosses may necessitate selection against the Fg1-Fg3-genotype in the segregating material. For example, with the cross of \u27Corsoy\u27 (Fg1 fg3) x \u27Hawkeye\u27 (fg1 Fg3) at Iowa State University, visual selection was carried out against chlorophyll deficient types during inbreeding in order to develop lines for a physiological study. At the time of selection it was not known that flavonol-glycoside genes were involved. Advanced lines were later classified using thin layer chromatography (Buttery and Buzzell, 1973
Research Notes: Agriculture Canada and United States Department of Agriculture
In an increase plot of foundation seeds of Harosoy in 1957 at Urbana, a number of Harosoy-type plants were found with flowers of a deeper red than the normal purple (P). The color is best described as magenta (M). This mutant was added to the Genetic Type Collection as T235
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