Signal Processing for Semiconductor Detectors

This is a tutorial paper designed to provide a balanced perspective on the processing of signals produced by semiconductor detectors. The general problems of pulse shaping to optimize resolution with constraints imposed by noise, counting rate and rise time fluctuations are discussed.     

Estimation of timber volume in a coniferous plantation forest using Landsat TM

Optimisation of economic return from forests requires that comprehensive forest inventory data be available to support the design of harvesting strategies. Such inventory data can potentially be obtained by remote sensing. This study investigates the accuracy with which wood volume (m3 ha -1) in a plantation forest can be calculated from Landsat TM data at the pixel and foreststand spatial scales. Wood volumes were estimated from regression analysis, nonparametric line-fitting, and an N-dimensional K-nearest-neighbour classification scheme. At the pixel scale, relations between Landsat data and measured wood volume were found to be significant but weak, with r2 values of 0.3, and with correspondingly poor estimates of wood volume (root-mean-square errors rmses of 100 m3 ha -1). By averaging the pixel-scale estimates, wood volume estimates of acceptable accuracy were obtained for forest-stand areas of about 40 ha (rmses of 46 m3 ha -1). Parametric regression performed slightly better overall than non-parametric line fitting techniques for estimating wood volume. Estimates of similar accuracy to those obtained by regression were also given by NK-classification at the pixel-scale, provided K was large ( 15), although the classifier produced biased results at the forest-stand scale. It is concluded that Landsat TM only provides an acceptable data source for estimating wood volumes in plantation forests for areas of about 40 ha and larger. The very low dynamic range in the Landsat data is probably a significant factor limiting its use for inventory at more detailed scales.     

Detailed active site configuration of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 at 1.9 A resolution

The three-dimensional structure of a new crystal form of methanol dehydrogenase from Methylophilus W3A1 has been obtained in the presence of substrate using data recorded at a synchrotron. The structure of this approximately 140 kDa heterotetramer, refined at 1. 9 A resolution, reveals the detailed configuration of its redox cofactor, pyrroloquinoline quinone (PQQ). C4, one of the oxygen-bearing atoms of this orthoquinone is in a planar configuration while C5, which bears the other quinone oxygen, is tetrahedral, suggesting that the PQQ is in the semiquinone redox state. The substrate binding site has been identified close to PQQ and to the side chain of Asp297, the putative active site base. The proximity of the hydroxyl of methanol to C5 of PQQ compared to the greater separation of the substrate methyl group from C5 supports the addition-elimination reaction mechanism involving a hemiketal intermediate.     

Inhibition of proliferation and expression of T-antigen in SV40 large T-antigen gene-induced immortalized cells following transplantations

In this paper the Authors reviewed the recent literature for a more comprehensive and clear vision of the epidemiological and pathological aspects of retroperitoneal sarcomas. The most effective procedures for a an early and accurate diagnosis were identified. Moreover, the different therapeutic choices were taken into account focusing on those provided of the major potential in terms of oncologically valid treatment.     

Association of chromosome 12p genetic polymorphisms with lung adenocarcinoma risk and prognosis

The mapping near Kras2 of pulmonary adenoma susceptibility 1 (Pas1), a major locus affecting inherited predisposition to lung cancer in mice prompted us to test the homologous human region (12p12) for association with lung adenocarcinoma, by a population-based study. We genotyped 213 lung adenocarcinoma patients and 219 healthy blood donor subjects for five polymorphic markers mapping in the putative region of interest. Three marker polymorphisms, located in a region spanning approximately 700 kb, were significantly associated with lung adenocarcinoma risk. Furthermore, polymorphisms in KRAS2 and PTHLH loci were also associated with tumor prognosis. These results suggest the existence of a human Pas1 homologous locus on chromosome 12p12.     

Intraoperative arthrography and the Ilizarov technique. Role in the correction of paediatric deformity and leg lengthening

We performed intraoperative arthrography of the knee in 12 children with congenital short femur, Blount's disease or Ollier's disease in whom the Ilizarov technique was used for correction of deformity, leg lengthening or both. In each case, arthrography revealed a joint surface considerably different from that assumed from plain radiographs, and resulted in a change in the placement of our reference wires before application of the frame. This gave significant improvement in the mechanical axis obtained at the time of removal of the frame. The technique is safe, cheap and easy to perform. It is a useful adjunct to the application of the Ilizarov frame when used for complex lengthening and correction of deformity in the leg.