A review and further analysis of the results of the defect detection trials

The Defect Detection Trials were initiated in the post-PISC I era when it was considered essential to determine under controlled conditions the capability of selected ultrasonic techniques to detect and size significant flaws. These trials were not intended to allow a statistical evaluation of either the capability or reliability of a particular team or technique since the number of tests had to be limited. However, useful conclusions relating to the effectiveness of specific ultrasonic techniques under the conditions relevant to the DDT can be drawn, and some guidance can be gained on factors which influence the reliability of inspection.

The analysis first considers defect detection and concludes that very high standards were achieved, with all the flaws being reported for DDT Plates 1 and 2 by all the teams. Secondly, the fraction of referable flaws which are correctly classified according to specified criteria is evaluated. In some cases the margin between classifying a flaw as acceptable or referable is extremely small, and tolerances on the sizing data are considered and causes of misclassification are assessed.

The contribution made by the tandem and pulse-echo techniques and the degree of redundancy in the detection data are reviewed.     

Author's Reply

In response to Luchini's comments, we recalculate the small-signal gain in planar-wiggler free-electron lasers. When all first-order contributions are included, the standard gain formula is obtained, as required by the Madey theorem.     

Urethral sphincterotomy for delivery of vesical calculus in the mare: a case report

A case of vesical calculus in which haematuria was not a presenting sign is described. Methods of removal of vesical calculi are discussed. In this case, urethral sphincterotomy facilitated delivery.     

TAPER: query-aware,partition-enhancement for large,heterogenous graphs

Graph partitioning has long been seen as a viable approach to addressing Graph DBMS scalability. A partitioning, however, may introduce extra query processing latency unless it is sensitive to a specific query workload, and optimised to minimise inter-partition traversals for that workload. Additionally, it should also be possible to incrementally adjust the partitioning in reaction to changes in the graph topology, the query workload, or both. Because of their complexity, current partitioning algorithms fall short of one or both of these requirements, as they are designed for offline use and as one-off operations. The TAPER system aims to address both requirements, whilst leveraging existing partitioning algorithms. TAPER takes any given initial partitioning as a starting point, and iteratively adjusts it by swapping chosen vertices across partitions, heuristically reducing the probability of inter-partition traversals for a given path queries workload. Iterations are inexpensive thanks to time and space optimisations in the underlying support data structures. We evaluate TAPER on two different large test graphs and over realistic query workloads. Our results indicate that, given a hash-based partitioning, TAPER reduces the number of inter-partition traversals by \(\sim \)80%; given an unweighted Metis partitioning, by \(\sim \)30%. These reductions are achieved within eight iterations and with the additional advantage of being workload-aware and usable online.     

High resolution microscopic survey of third metacarpal articular calcified cartilage and subchondral bone in the juvenile horse: possible implications in chondro-osseous disease

The aim was to survey articular calcified cartilage (ACC) and subchondral bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of young horses with minimal or no signs of musculo-skeletal abnormality. Back-scattered electron scanning electron microscopy (BSE SEM) was conducted on polymethyl methacrylate-embedded mediolateral slices and macerated wedges of the right distal Mc3 from seven each of trained and untrained 2-year-old Thoroughbred horses. Furrows or grooves visible to the naked eye in the mineralizing front (MF) of ACC are the commonest "lesion" and are most common in the palmar portions of the medial and lateral condylar grooves. Cracks running predominantly in the parasagittal plane that infill with hypercalcified matrix are found in the same domain. Common to all these defects are deficiencies or absence of the ACC MF. Other anomalies include local excrescences or depressed areas of the MF. More important condylar lesions show displaced fragmented hypermineralized ACC with underlying excess resorption in the bone domain, leaving a thin ACC layer with cavernous space beneath it. The fragments may dislodge and displace to the joint space. Obvious although small lesions are present in horses that have undertaken little or no training. The nature and sites of the lesions indicate that they are possibly the earliest morphological evidence of changes that may lead to specific joint abnormalities. The lesions appear unlikely to be solely due to functional traumatic forces, and developmental influences are likely to be important in their initiation.     

User-friendly algorithms for estimating completeness and diversity in randomized protein-encoding libraries

Directed evolution of proteins depends on the production ofmolecular diversity by random mutagenesis. While a number ofmethods have been developed for introducing this diversity,the best ways to sample it are not always clear. Here we usedsimple statistics to analyse completeness and diversity in randomizedlibraries generated by oligonucleotide-directed mutagenesis,error-prone polymerase chain reaction (epPCR) and in vitro recombinationof highly homologous sequences. For oligonucleotide-directedmutagenesis, we derive equations to estimate how complete agiven library is expected to be and also to predict the sizeof library required to give a fixed probability of being 100%complete. We describe the statistical bases for computer programswhich estimate the number of distinct variants represented inepPCR and shuffled libraries, dubbed PEDEL and DRIVeR, respectively.These programs allow the user to calculate (rather than guess)the diversity represented in a given library and also provideempirical guidelines for maximizing this diversity. PEDEL andDRIVeR are available at www.bio.cam.ac.uk/