Rainfall attenuation at 36 GHz and 55 GHz

Simultaneous rainfall measurements at 36 GHz and 55 GHz on a common 4.1 km path show, under the conditions of these experiments, that the attenuation due to rainfall lies between the attenuation values predicted by the lognormal and the Best rain drop size distributions.     

THE MYCOFLORA OF BARLEYS ACCEPTED AND REJECTED FOR MALTING

Barleys were examined by direct and dilution plating before purchase for drying and subsequent malting. The mould flora of barleys rejected because of heating was characterised by lower proportions of field fungi, particularly Cladosporium spp, and higher proportions of storage fungi, particularly Aspergillus glaucus (group), than in undried barleys which had not heated. Results indicated that microbiological analysis could be used to resolve whether self-heating of undried barley has occurred on the farm before the barley has been delivered free of heat to meet a purchaser's specification.     

The future of the microcomputer as a classroom teaching aid: An empirical approach to crystal gazing

A microcomputer can be a valuable teaching aid but its current use in secondary schools is so infrequent as to make it difficult to assess its future potential. We observed 174 school lessons during which 17 teachers employed a microcomputer regularly with a chosen class for a whole term. The aim was to provide a glimpse into the future when there will be better computer facilities and more expertise among teachers. During the term, we detected no drop in interest as the novelty diminished and lessons tended to improve as teachers became more experienced in using the medium. Two terms later the majority of teachers were still using a microcomputer regularly as a teaching aid and there was some spread of interest to other teachers in the same schools. The results suggest that, in subjects like mathematics, computer-aided teaching will be successfully adopted by the majority of teachers if the necessary resources are available. The computer appears to be a very versatile teaching aid and we found no grounds for strongly recommending any particular style of use.     

A cost-effective eigensolution method for large systems with Rockwell NASTRAN

The Lanczos method with reorthogonalization based on Householder transformations has been implemented in Rockwell's version of the COSMIC-released NASTRAN program for partial solution of a large-scale symmetric eigenvalue problem. A special technique has been included for restarting Lanczos iteration with a new random vector, partly to avoid premature termination associated with a null or linearly dependent Lanczos feed vector and partly to discover multiple eigenvalues. The developed Lanczos-Householder algorithm with built-in random restart capability shows appreciable cost-savings over the conventional subspace iteration technique as well as the COSMIC NASTRAN method, FEER, which utilizes the modified Gram-Schmidt process to reorthogonalize the Lanczos feed vector with respect to those previously converged.     

Dilation and Intercalation of Gases Within Carbon Nanostructures

We present a study of the mutual effects of the interactions between an adsorbed gas and an adsorbing porous environment when the possible expansion of the pore is considered. In particular, we have studied the dilation of a carbon nanotube bundle when quantum gases are absorbed within the interstitial channels and also the possibility of gas (H₂ and ⁴ He) intercalation between two graphene planes when the distance between them is allowed to change. We find that the dilation of the bundle increases significantly the binding energy of adsorption while intercalation between two graphene sheets is energetically unfavorable for both gases.     

Physiological and behavioral responses of stonefly nymphs to enhanced limestone treatment of acid mine drainage

A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD, to enhance limestone neutralization of AMD. We conducted laboratory studies to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Plecoptera) exposed to effluents produced by the treatment system. Survival, sodium balance, drift, and feeding responses by P. proteus to treated and untreated AMD were examined. P. proteus nymphs exhibited significant losses of whole body sodium in exposures to untreated AMD. Nymphs exposed to treated effluents experienced no loss of whole-body sodium. Nymphs exposed to untreated AMD showed elevated drift rates and depressed feeding rates relative to those of nymphs exposed to treated AMD, and to AMD-free controls. No significant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The treatment system, with and without CO2 pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physiological function.     

Effect of eicosapentaenoic acid on the proliferation and incidence of apoptosis in the colorectal cell line HT29

Fish oil has been shown to reduce the induction of colorectal cancer in animal models by a mechanism which may involve suppression of mitosis, increased apoptosis, or both. We used the human colonic adenocarcinoma cell line HT29 to explore the effects of the long-chain n-3 polyunsaturated fatty acid eicosapentaenoic acid (EPA) on cell proliferation and death in vitro. Cells were cultured in media containing EPA at 5, 10, and 15 μg/mL. Cell number and thymidine incorporation were used to quantify proliferation, and cell cycle effects were studied using flow cytometry. Gel electrophoresis, annexin-V binding, and morphological criteria were used to characterize apoptosis. Adherent cells and freely floating detached cells were treated as two distinct populations. In the presence of EPA at 10 and 15 μg/mL there was a marked reduction in the growth rate of adherent HT29 colonies, owing to an increased detachment of adherent cells. After treatment with 10 or 15 μg/mL EPA the proportion of adherent cells in S-phase increased, indicating either a block in late S-phase or early G2. Floating cells showed evidence of extensive DNA cleavage, but the proportion of floating cells with sub G0 DNA content declined on treatment with 10 or 15 μg/mL EPA even though the number of floating cells increased. We conclude that EPA does not inhibit mitosis of adherent cells, but increases the rate at which they become detached from the substrate, probably at an early stage in the initiation of apoptosis. This mechanism may be analogous to “anoikis”, or induction of apoptosis in response to loss of cell contact, and may contribute to the anticarcinogenic effects of fish oil in vivo.