QSAR studies of the pyrethroid insecticides. Part 3. A putative pharmacophore derived using methodology based on molecular dynamics and hierarchical cluster analysis

Previous studies of the conformational behaviour of a group of synthetic pyrethroid insecticides have been extended to a more structurally diverse set. This includes compounds with different backbones and differing stereochemistry, with both Types I and II biological activity. These compounds also encompass a large range of biological activities. A parameterisation of the CHARMM force field for these compounds has been performed and the extra parameters are reported. Conformational sampling, using molecular dynamics (MD), has been performed for each of the 41 active structures. The accessible conformations of each have been characterised by the values of the common torsion angles using hierarchichal cluster analysis (HCA). A further CA, based on the centroids derived from the conformational sampling, identified a conformation common to at least 39 of the 41 structures. The critical torsion angles of this conformation lie at the centre of the molecule about the ester linkage and are defining an extended conformation, which differs from the minimum energy conformation of deltamethrin used previously. This may represent a putative pharmacophore for kill. The methods used here improve significantly on those used previously. The CHARMM force field was parameterised for the compounds and an improved method of conformational sampling, based on centroid clustering, has also been used.     

Implementation of Digital Electronic Arithmetics and its application in image processing

In this paper we introduce new algorithm implementations of a new parametric image processing framework that will accurately process images and speed up computation for addition, subtraction, and multiplication. Its potential applications include computer graphics, digital signal processing and other multimedia applications. This Parameterized Digital Electronic Arithmetic (PDEA) model replaces linear operations with non-linear ones. The implementation of a parameterized model is presented. We also present the design of arithmetic circuits including parallel counters, adders and multipliers based in two high performance threshold logic gate implementations that we have developed. We will also explore new microprocessor architectures to take advantage of arithmetic. The experiments executed have shown that the algorithm provides faster and better enhancements from those described in the literature. The FPGA chips used is Spartan 3E from Xilinix. The critical length in the circuit implemented on the FPGA had the minimum period for the proposed subsystem is 10.209 ns (maximum frequency 97.957 MHz). Maximum power consumed is 2.4 mW using 32 nm process and we used parallelism and reuse of the Hardware components to accomplish and speed up the process.     

An automated enzymic micromethod for the measurement of fat in human milk

Most (98%) of the fat in human milk is present as triglycerides. This paper describes the use of a clarification procedure that enables the level of human milk fat to be determined by measurement of glycerol released by enzymic hydrolysis of triglycerides. The method requires only 10-50 microliters milk, thus presenting a possible technique for work with small mammals, and is suitable for use with autoanalysers, permitting rapid sample throughput.     

A novel surgical method of repair for Stahl's ear: a case report and review of current treatment modalities

Stahl's ear is a congenital malformation of the auricle, which is uncommon in non-Oriental societies. A number of different treatment modalities have been suggested, many of which yield unpredictable results. We review current treatment modalities from the English literature and describe a novel, simple surgical method of repair. First, a helical rim incision is made to expose the abnormal third crus and upper pole of the ear. The third crus is excised as a narrow wedge of cartilage and posterior skin, and the defect is closed primarily. The free third crus cartilage is then grafted onto the scaphal cartilage in an anatomically correct position to form a superior crus. The anterior skin flap is redraped and bolstered over this graft. Only a very small scar on the helical rim remains visible anteriorly.     

On-site treatment of a motorway service area wastewater using a package sequencing batch reactor (SBR).

A sequencing batch reactor (SBR) treating the effluent of a motorway service station in the south of England situated on a major tourist route was investigated. Wastewater from the kitchens, toilets and washrooms facilities was collected from the areas on each side of the motorway for treatment on-site. The SBR was designed for a population equivalent (p.e.) of 500, assuming an average flow of 100 m3/d, influent biochemical oxygen demand (BOD) of 300 mg/l, and influent suspended solids (SS) of 300 mg/l. Influent monitoring over 8 weeks revealed that the average flow was only 65 m3/d and the average influent BOD and SS were 480 mg/l and 473 mg/l respectively. This corresponded to a high sludge loading rate (F:M) of 0.42 d(-1) which accounted for poor performance. Therefore the cycle times were extended from 6 h to 7 h and effluent BOD improved from 79 to 27 mg/l.     

The Practical Application of Ozone Gas as an Anti-fungal (Anti-mold) Agent

We evaluated the ability of a portable ozone generating machine (Viroforce 1000) to inactivate 13 different species of environmental fungi. Samples, prepared as wet or dried films, were subjected to one or two cycles of treatment (35 ppm ozone for 20 minutes, with a short burst of?>90%?relative humidity), and measured for residual viability. Treatments could inactivate 3 log₁₀ cfu (colony forming units) of most of the fungi, both in the laboratory and in simulated field conditions, on various surfaces. We conclude that the ozone generator would be a valuable decontamination tool for mold removal in buildings.