Software in the new millennium: a virtual roundtable

What will software look like in the future? To answer this question, we conducted a survey of our editorial and industrial advisory boards, as well as a few outsiders. We constructed a set of 13 questions that we thought reflected the original query. We then circulated these questions to our boards, with a request to respond to the questions, or be extend them with additional are questions as appropriate. The answers were far ranging and sometimes surprising.     

Stability of the body-centered cubic gamma phase in the uranium-zirconium-niobium system

A thermodynamic representation of the stability of the binary gamma phases has been developed for the U-Zr, U-Nb and Zr-Nb binary systems. This has permitted the calculation of the miscibility gaps in the ternary system. The three binary gaps merge to form a large three-phase region in the middle of the composition trangle. Because of the large coherency energies, the spinodal decomposition in the U-Nb and Zr-Nb gaps will be drastically modified, but a large region remains in the ternary system where the decomposition products have small coherency energies such that spinodal decomposition is probable. From these results, we have identified the four decomposition processes in Mulberry (U-16.6 at% Nb-5.6 at% Zr) as being discontinuous and spinodal decomposition within the miscibility gap, the diffusionless formation of α and the formation of (α + γ) from the supersaturated gamma phase.     

A Recursive Orthogonal Least Squares Algorithm for Training RBF Networks

A recursive orthogonal least squares (ROLS) algorithm for multi-input, multi-output systems is developed in this paper and is applied to updating the weighting matrix of a radial basis function network. An illustrative example is given, to demonstrate the effectiveness of the algorithm for eliminating the effects of ill-conditioning in the training data, in an application of neural modelling of a multi-variable chemical process. Comparisons with results from using standard least squares algorithms, in batch and recursive form, show that the ROLS algorithm can significantly improve the neural modelling accuracy. The ROLS algorithm can also be applied to a large data set with much lower requirements on computer memory than the batch OLS algorithm.     

Assessment of non-uniform malathion distribution for insect control in a commercial wheat silo

Experimental (non-uniform) and conventional malathion treatments of wheat, stored in 2000 tonne vertical steel bins were compared. For the experimental treatment, grain pretreated with malathion at 750–800 ppm was added to an untreated grain stream during inloading of a silo, so that pretreated grain comprised about 1% of the bulk. Conventional treatment consisted of continuous spraying of a similar grain stream with an emulsion of malathion. Mean overall malathion levels of approximately 5–6 ppm were obtained in both silos.Distribution of insecticide in the two treatments was compared by assaying groups of 25 grains taken from each bin. Significantly increased non-uniformity of distribution of insecticide was found in the experimental treatment which was considered to account for the greater persistence of malathion residues.Bioassays to indicate the potential of adult Tribolium castaneum (Herbst) and Sitophilus oryzae (L.) to develop infestations were conducted on wheat from the experimental and conventional treatments throughout their respective 10 and 8 months storage periods. Results indicated effective suppression of T. castaneum infestation throughout the storage periods in both silos. After 6 months storage, the conventional treatment did not prevent infestation by S. oryzae, whereas the experimental treatment remained effective throughout the 10 months storage period; suggesting that the proposed method has the economic advantage of eliminating retreatment.     

Influence of malathion distribution on the protection of wheat grain against insect infestation

Laboratory experiments indicated that treatment of a small proportion of a wheat bulk with high concentrations of malathion may prove a more effective method of application than attempting to treat all grains uniformly with the same overall level of insecticide. Adults of Sitophilus oryzae (L.), Tribolium confusum Duv., Rhizopertha dominica F. were exposed in the laboratory to wheat samples in which varying percentages of the grains were treated with malathion to give the same overall level of insecticide, usually 10 ppm. Treating 1 or 2 per cent of grains gave as effective control as treating all grains, but control was inferior when only 0·1 or 0·2 per cent of grains were treated. The relative control levels in wholly and partially treated grain samples were not affected by varying the overall level of malathion between 1 and 11 ppm. There was a trend to greater persistence of malathion as the concentration on grains was increased.     

The effect of external vorticity on stagnation-point heat transfer at high prandtl number

The strong sensitivity of stagnation-point heat transfer to the presence of free-stream turbulence has been attributed to vorticity amplification by stretching of vortex filaments. A mathematical model proposed by Sutera, Maeder and Kestin is examined for the case of very high Prandtl number (Pr). Asymptotic solutions are obtained for the limit Pr → ∞. These show that the heat-transfer sensitivity continues to increase with Prandtl number. Approximately 95 per cent of the asymptotic value of the stagnation-point heat-transfer coefficient is attained at Pr = 100.     

Col4a3-/- Mice on Balb/C Background Have Less Severe Cardiorespiratory Phenotype and SGLT2 Over-Expression Compared to 129x1/SvJ and C57Bl/6 Backgrounds

Alport syndrome (AS) is a hereditary renal disorder with no etiological therapy. In the preclinical Col4a3^-/- model of AS, disease progression and severity vary depending on mouse strain. The sodium-glucose cotransporter 2 (SGLT2) is emerging as an attractive therapeutic target in cardiac/renal pathologies, but its application to AS remains untested. This study investigates cardiorespiratory function and SGLT2 renal expression in Col4a3^-/- mice from three different genetic backgrounds, 129x1/SvJ, C57Bl/6 and Balb/C. male Col4a3^-/- 129x1/SvJ mice displayed alterations consistent with heart failure with preserved ejection fraction (HFpEF). Female, but not male, C57Bl/6 and Balb/C Col4a3^-/- mice exhibited mild changes in systolic and diastolic function of the heart by echocardiography. Male C57Bl/6 Col4a3^-/- mice presented systolic dysfunction by invasive hemodynamic analysis. All strains except Balb/C males demonstrated alterations in respiratory function. SGLT2 expression was significantly increased in AS compared to WT mice from all strains. However, cardiorespiratory abnormalities and SGLT2 over-expression were significantly less in AS Balb/C mice compared to the other two strains. Systolic blood pressure was significantly elevated only in mutant 129x1/SvJ mice. The results provide further evidence for strain-dependent cardiorespiratory and hypertensive phenotype variations in mouse AS models, corroborated by renal SGLT2 expression, and support ongoing initiatives to develop SGLT2 inhibitors for the treatment of AS.     

Thematic labelling from hyperspectral remotely sensed imagery: trade-offs in image properties

The effect of spatial, spectral and noise degradations on the accuracy of two highly contrasting thematic labelling scenarios was investigated. The study used hyperspectral imagery of a site near Falmouth, UK, to assess the effect of the data degradations on the accuracy of supervised classification when the H-resolution scene model was applicable and on labelling when an L-resolution scene model was applicable and no ground data were available. In both scenarios, the spatial, spectral and noise degradations affected the accuracy of labelling. However, over the range of degradations investigated, the noise content of the data was consistently noted to be a major variable affecting the accuracy of labelling.     

The importance of choosing attractors for optimizing chaotic communications

In this brief, we consider methods to improve the performance of chaotic communication schemes. We study a system using a receiver which explicitly includes the presence of noise in the channel. We show how the choice of chaotic dynamical system generating the transmitted signal is crucial. We observe a large variation in bit error rate performance of the system as parameters in the maps are changed, and we propose a simple explanation for this variation.