A Genetic Programming Approach to Rainfall-Runoff Modelling

Planning for sustainable development of water resources relies crucially on the data available. Continuous hydrologic simulation based on conceptual models has proved to be the appropriate tool for studying rainfall-runoff processes and for providing necessary data. In recent years, artificial neural networks have emerged as a novel identification technique for the modelling of hydrological processes. However, they represent their knowledge in terms of a weight matrix that is not accessible to human understanding at present. This paper introduces genetic programming, which is an evolutionary computing method that provides a transparent and structured system identification, to rainfall-runoff modelling. The genetic-programming approach is applied to flow prediction for the Kirkton catchment in Scotland (U.K.). The results obtained are compared to those attained using two optimally calibrated conceptual models and an artificial neural network. Correlations identified using data-driven approaches (genetic programming and neural network) are surprising in their consistency considering the relative size of the models and the number of variables included. These results also compare favourably with the conceptual models.     

A Conjoint-based approach to student evaluations of teaching performance

In recent years, the need for greater accountability and improvement in teaching’s quality has become a major issue in higher education. The results of student evaluation of teaching are increasingly used to make judgments about teaching quality, career advancement, and the funding of teaching itself. An important component of any such student evaluation is the communication of rating results in a manner that allows for fair and meaningful interpretations and comparisons of results by a wide range of evaluation users. In this paper, an approach for a more objective evaluation of university teachers is proposed, one which is based on previously obtained conjoint analysis data concerning criteria importance from a student’s point of view. Therein, an illustrative example is given to demonstrate the efficiency and practical usage of such a proposed approach.     

Sensitivity analysis of experimentally determined grounding gridimpulse characteristics

The paper presents an experimental determination of the grounding grid impulse characteristics procedure. The measuring circuit configuration and characteristics of the applied equipment are given. Some of the numerous experimental results for three grounding grid configurations are presented. The paper provides the analysis of the results obtained for various impulse current shapes, magnitudes and discharge points. The results shown are related to the cases without soil ionization around the grid elements     

Assessing the performance of a spectral reflectance estimation method based on a diffraction grating and a spectroradiometer

Constant improvements in digital cameras have made it possible to use these devices for colour acquisition and reproduction at an advanced level. It is known that a colour match for all observers when changing illumination can only be achieved by matching spectral data. Obtaining spectral data from digital camera RGB values could provide a new way of using the digital camera as a spectrophotometric tool or as a high‐quality colour‐capturing system that is required in more demanding applications. In the present study, two spectral reflectance estimation methods were examined – the Imai–Berns method (ImaiBerns) and the spectral‐sensitivity‐based method (SpecSens). The purpose of the research was to simplify the procedure of the SpecSens method by using a diffraction grating and a spectroradiometer instead of a monochromator, and to compare the results with those of the ImaiBerns approach. Obtained spectral reflectance estimates were evaluated using the root‐mean‐square error and ?E₀₀ metrics. Results of the research show that the ImaiBerns method was superior to SpecSens, most likely because the former method does not require knowledge of the camera spectral sensitivities, which often introduces errors into reflectance estimation calculations. Both methods were successful in predicting black, brownish, and dark patches, as indicated by a low root‐mean‐square error, as well as unsaturated pastel, pink, or skin colours, which produced low ?E₀₀ values. On the other hand, many of the patches with a low root‐mean‐square error also exhibited high ?E₀₀ values, while bright, nearly‐white patches were characterised by a high root‐mean‐square error.     

Differential localization of VE- and N-cadherins in human endothelial cells: VE-cadherin competes with N-cadherin for junctional localization

The two major cadherins of endothelial cells are neural (N)-cadherin and vascular endothelial (VE)- cadherin. Despite similar level of protein expression only VE-cadherin is located at cell-cell contacts, whereas N-cadherin is distributed over the whole cell membrane. Cotransfection of VE-cadherin and N-cadherin in CHO cells resulted in the same distribution as that observed in endothelial cells indicating that the behavior of the two cadherins was not cell specific but related to their structural characteristics. Similar amounts of alpha- and beta-catenins and plakoglobin were associated to VE- and N-cadherins, whereas p120 was higher in the VE-cadherin complex. The presence of VE-cadherin did not affect N-cadherin homotypic adhesive properties or its capacity to localize at junctions when cotransfectants were cocultured with cells transfected with N-cadherin only. To define the molecular domain responsible for the VE-cadherin-dominant activity we prepared a chimeric construct formed by VE-cadherin extracellular region linked to N-cadherin intracellular domain. The chimera lost the capacity to exclude N-cadherin from junctions indicating that the extracellular domain of VE-cadherin alone is not sufficient for the preferential localization of the molecule at the junctions. A truncated mutant of VE-cadherin retaining the full extracellular domain and a short cytoplasmic tail (Arg621-Pro702) lacking the catenin-binding region was able to exclude N-cadherin from junctions. This indicates that the Arg621-Pro702 sequence in the VE-cadherin cytoplasmic tail is required for N-cadherin exclusion from junctions. Competition between cadherins for their clustering at intercellular junctions in the same cell has never been described before. We speculate that, in the endothelium, VE- and N-cadherin play different roles; whereas VE-cadherin mostly promotes the homotypic interaction between endothelial cells, N-cadherin may be responsible for the anchorage of the endothelium to other surrounding cell types expressing N-cadherin such as vascular smooth muscle cells or pericytes.     

Evaluation of barley as a source of protein for chicks. I. Variety and nitrogen application in relation to protein content and amino-acid composition of the seed

Seventy-six samples of barley embracing 14 varieties grown under various conditions of nitrogen fertilisation in different locations in the U.K. were examined for nitrogen content and 14 samples were analysed for their total content of amino acids other than tryptophan. Top dressing with nitrogenous fertilisers during growth resulted in the production of grain with a higher nitrogen content as well as an increased overall yield of nitrogen/hectare. The growth locality had a greater effect upon the nitrogen content of the harvested seed than did the application of nitrogen to the growing crop. Lysine content was inversely proportional to crude protein content for barleys containing between 8 and 11% crude protein and, in consequence, within this range the yield of lysine/ton of grain was of the same order.     

Cytotoxicity of some catalysts commonly used in the synthesis of copolymers for biomedical use

The cytotoxicity of four catalysts commonly used for the synthesis of copolymers for biomedical use, such as segmented polyurethanes, was evaluated towards two types of cells, the first being the well-characterized cell line Swiss 3T3 mouse fibroblasts, the second the actual living system that faces any device in contact with blood, i.e. human endothelial cells (HEC). The catalysts were two tertiary aliphatic amines: TMBDA (tetramethylbutanediamine), and DABCO (1–4 diazo (2,2,2) octane); two alkyl tin compounds: DBTDL (dibutyl-tin-dilaurate), and SnOct (stannous octoate). Cytotoxicity tests were carried out by adding to the culture medium, after cell adhesion, different concentrations of each catalyst in dimethylsulphoxide, and keeping them in contact with the monolayer for 72 h. All the catalysts proved to be cytotoxic, although at different extent (in the order: DABCO < TMBDA < SnOct < DBTDL); their dose inhibiting 50% of cell growth (IC50) came out to be lower for 3T3 fibroblasts than for HEC, with the exception of DBTDL, which showed a similar toxicity for both the cell lines. As an example, the cytotoxicity of a polyurethane-amide, laboratory synthesized with DBTDL as catalysts, was checked with fibroblasts. By using both the method of the extract, and that of the direct contact (through a microporous membrane), a moderate to severe cell growth inhibition, related to the Sn content in the material, was observed.     

Sex differences in patients with mesial temporal lobe epilepsy

Possible sex differences in the pattern of interictal hypometabolism were investigated, and also seizure spread in patients with mesial temporal lobe epilepsy (n=48) and hippocampal sclerosis (MTLE). Male patients (n=21) more often had a frontal lobe hypometabolism ipsilateral to the seizure onset (p<0.0001) and a spread of epileptiform activity to this region (p=0.001). By contrast, female patients more often exhibited hypometabolism (p=0.0052) and an ictal spread to the contralateral temporal lobe (p=0.0097). These findings suggest sex differences in spatial distribution of brain dysfunction in MTLE, perhaps reflecting sexual dimorphism in regional cerebral connectivity.