A rapid computational filter for predicting the rate of human renal clearance

In silico models that predict the rate of human renal clearance for a diverse set of drugs, that exhibit both active secretion and net re-absorption, have been produced using three statistical approaches. Partial Least Squares (PLS) and Random Forests (RF) have been used to produce continuous models whereas Classification And Regression Trees (CART) has only been used for a classification model. The best models generated from either PLS or RF produce significant models that can predict acids/zwitterions, bases and neutrals with approximate average fold errors of 3, 3 and 4, respectively, for an independent test set that covers oral drug-like property space. These models contain additional information on top of any influence arising from plasma protein binding on the rate of renal clearance. Classification And Regression Trees (CART) has been used to generate a classification tree leading to a simple set of Renal Clearance Rules (RCR) that can be applied to man. The rules are influenced by lipophilicity and ion class and can correctly predict 60% of an independent test set. These percentages increase to 71% and 79% for drugs with renal clearances of < 0.1 ml/min/kg and > 1 ml/min/kg, respectively. As far as the authors are aware these are the first set of models to appear in the literature that predict the rate of human renal clearance and can be used to manipulate molecular properties leading to new drugs that are less likely to fail due to renal clearance.     

Properties and performance modelling of finite buffer M/G/1/K networks

Finite buffer, single-server queueing systems and networks are difficult to analyze since the length of time a customer spends in the system does not follow the Markovian property. A two-moment approximation schema is developed for the probability distribution of M/G/1/K systems and extended to the analysis of M/G/1/K   queueing networks. The general purpose of this paper is to develop a flexible and practical transform-free approach for computing the probability distribution and performance measures of the system as well as identify the underlying properties of these systems. It is shown that for most performance measures, a sigmoid or S-shaped curve with an inflection point at ρ=1$\rho =1$ appears as K→∞$K\to \infty$. This has direct implications for the analysis and optimization of such systems. The performance modelling of the M/G/1/K queueing networks of general topologies along with extensive numerical results accompany the paper along with the linear concave performance measures for these systems.     

A microcomputer system for processing natural languages

This correspondence describes a microcomputer system, called ?BE (for microprocessor-based English), for processing natural languages. Its techniques and facilities, however, should be extendible to other languages. By using the microprocessor as special purpose hardware for several functions of a natural language processor (in particular, hashing and parsing), the system aids computational linguists by increasing the computational power available for natural language investigations. An overview of ?BE is given followed by a more detailed discussion of the hasher and parser. The paper concludes with specific applications of the microprocessor system to computational linguistics. ?BE is not based on a particular theory of language so that the system's user may define his own theory and investigate its consequences. ?BE contains facilities and capabilities to assist such investigations.     

A national survey of the weight loss in pig carcasses between slaughter and 24 hours post mortem

A national survey was carried out in Great Britain in 1978/79 to determine the weight loss occurring in pig carcasses between slaughter and 24 hours post mortem. A total of 20,600 carcasses were measured over a 12-month period, the sample covering forty-eight slaughtering plants and the main market weights of pig. At 24 hours post mortem, the overall mean weight loss was estimated to be 2·27% of the hot weight. The figure differed little between market weights or between times of the year, but there were important differences between slaughtering plants.     

A dual method for maximum entropy restoration

A simple iterative dual algorithm for maximum entropy image restoration is presented. The dual algorithm involves fewer parameters than conventional minimization in the image space. Mini-computer test results for Fourier synthesis with inadequate phantom data are given.     

Portable Device for Detection of Petit Mal Epilepsy

We have developed and tested a portable device that analyzes the electroencephalogram (EEG) to determine if petit mal epilepsy waveforms are present. Clinicians should rimd it useful in diagnosing seizure activity of their patients. The micropower, battery-operated, portable device indicates a seizure has occurred if three criteria are satisfied: 1) frequencies of 2.5-7 Hz, 2) large amplitude waves, and 3) minimum number of waves per second. Levels and counts are adjustable, thus insuring high reliability against noise artifacts and permitting each subject to be individually fitted. The device has shown promise in giving the patient a possible mechanism of seizure control or suppression.     

A thin film electrochromic display based on the tungsten bronzes

The main features of a passive thin film display cell based on the electrochemically reversible formation of a tungsten bronze according to the reaction

$\text{(colourless) WO}{}_3\text{+ x}\text{M}{}^{\mathrm{+}}\text{+ x}\text{e}{}^{\mathrm{?}}\text{?}\text{M}{}_{\mathrm{x}}\text{WO}{}_3\text{(blue)}$

where 0 < x < 1 are considered. Chemical analysis of an electrochemically coloured WO₃ film has confirmed the presence of M. It is shown that a critical requirement of these cells is that D_τ(qC_m/Q)² ≈ 1, where the symbols are, in order, the M⁺ diffusion coefficient, the required device response time, the electronic charge, the maximum practical volume concentration of M in the WO₃ film and lastly the area colouring charge. Typical energy requirements might be about 10 mJ cm^?2 per complete cycle in a favourable case.Ionic injection overpotentials and ionic diffusion both appear to play a significant role in determining cell currents. Preliminary diffusion coefficient results for Li⁺ in r.f. sputtered WO₃ films are reported, and their predicted dependence of film structure is discussed. The optical absorption of coloured WO₃ films is presented, and it is interpreted as being predominantly due to free-electron intraband transitions.