Parallel computing in information retrieval - An updated review

The progress of parallel computing in Information Retrieval (IR) is reviewed. In particular we stress the importance of the motivation in using parallel computing for Text Retrieval. We analyse parallel IR systems using a classification due to Rasmussen [1] and describe some parallel IR systems. We give a description of the retrieval models used in parallel Information Processing.. We describe areas of research which we believe are needed

The importance of understanding individual differences in Down syndrome

In this article, we first present a summary of the general assumptions about Down syndrome (DS) still to be found in the literature. We go on to show how new research has modified these assumptions, pointing to a wide range of individual differences at every level of description. We argue that, in the context of significant increases in DS life expectancy, a focus on individual differences in trisomy 21 at all levels—genetic, cellular, neural, cognitive, behavioral, and environmental—constitutes one of the best approaches for understanding genotype/phenotype relations in DS and for exploring risk and protective factors for Alzheimer’s disease in this high-risk population

The neutron spectrum of plutonium fluoride

The neutron spectrum of PuF<SUB>4</SUB> has been theoretically calculated using the measured total <SUP>19</SUP>F(α, n)<SUP>22</SUP>Na cross sections, and compared with available experimental data. There is good agreement with regard to the main peak as well as the maximum energy of the spectrum. The calculated spectrum explains all the features of the observed spectrum

Calculations of responses to representative neutron spectra of albedo neutron dosemeters incorporating LiF thermoluminescent detectors

The responses to representative neutron spectra from the Health Physics Research Reactor in the USA of some albedo dosemeter configurations using commercially available LiF TLD chips have been calculated, and methods suggested for correcting the energy response of albedo dosemeters

Sodium pyrophosphate- a new thermoluminescent detector

Sodium pyrophosphate doped with dysprosium oxide in the ratio of 1000 : 1 by weight has been developed as a thermoluminescent detector. The gamma ray response characteristics of the prepared phosphor along with the thermal and fast neutron responses are reported in this paper. The phosphor has an emission spectrum consisting of two peaks at 480 nm and 580 nm. It has three glow peaks at 90°C, 181°C and 228°C. The low temperature peak decays rapidly on storage and the glow peak at 181°C is stable and useful for dosimetry purposes. The integrated thermoluminescence has always been measured three days after irradiation. The trap depths for the three glow peaks have been determined as 0.89 eV, 1.24 eV and 1.58 eV respectively. The optimum annealing temperature of the phosphor is found to be 400°C. The photon energy response of the new phosphor was estimated theoretically and experimentally and found to be similar to that of LiF (TLD-100). The exposure range covered was from 0.41 C·kg−1 to 3.30 C·kg−1 of 60Co gamma radiation and the TL output is found to be linear in this range. The response of the phosphor per unit thermal neutron fluence is equivalent to 1.3 × 10−14 C·kg−1 of 60Co gamma radiation. The kerma in sodium pyrophosphate for various neutron energies were computed. A fast neutron exposure of 10 mSv gives a TL output equivalent to 1.95×10−6 C·kg−1 of 60Co gamma rays

Quantitative analysis of the effects of physiologic brain motion on point-resolved spectroscopy

Although single-voxel proton MR spectroscopy is a noninvasive method that enables measurement of brain metabolite concentrations, it has been shown that physiologic brain motion causes inaccuracies in measurement of metabolite concentrations and increases the overall SD of the measurements when the stimulated echo acquisition mode (STEAM) is used. We tested the hypothesis that the point-resolved spectroscopy (PRESS) technique is less sensitive to physiologic brain motion than the STEAM technique. In 10 healthy subjects, spectra were obtained from a voxel located in the left basal ganglia by using the PRESS sequence with cardiac gating and without water suppression to assess global phase change as a function of physiologic brain motion. This was accomplished by acquiring data at various time delays from the R wave throughout the cardiac cycle. Subsequently, spectra were obtained in 10 healthy subjects by using PRESS both without and with cardiac gating, and with water suppression, to determine whether brain motion resulted in a statistically significant difference in mean and SD of measured metabolite concentration. At various time delays from the R wave throughout the cardiac cycle, no significant global phase difference was noted in water signal intensity. In addition, when PRESS data were obtained both without and with cardiac gating (by using an optimal delay obtained from previously published data by using STEAM), no significant difference was seen in measured metabolite concentrations and SDs. The PRESS technique is relatively insensitive to physiologic brain motion

The use of a chitosan dressing with silver in the management of paediatric burn wounds: a pilot study.

OBJECTIVE: Traditional burn dressings demonstrate unfavourable tendencies of shrinking when wet and failing to maintain their integrity when manipulated. To overcome these obstacles, gel-forming fibre dressings have emerged as an alternative. Our objective was to observe the clinical properties and healing ability in the setting of burn wounds in a paediatric centre of a chitosan-based dressing containing silver. METHODS: A sample of 12 partial-thickness burns in 10 children were identified for treatment with the chitosan-based silver dressing. The dressings were moistened before application, and monitored for any shrinkage on application. Patients were monitored for healing at outpatient follow-up visits and the dressings were allowed to separate as healing occurred. RESULTS: We treated 12 burns in 10 children with an average age of 5.2 years. The burns had an average proportion of total body surface area (TBSA) of 3.6 % and involved the trunk and all extremities. Wounds healed mostly or completely in an average of 8.3 days. Dressings retained their size when wet and integrity when removed. No burns were found to be infected at any point in the study. CONCLUSIONS: The chitosan-based dressing offered an optimal environment for moist wound management, and did not demonstrate the shrinkage or disintegration that diminishes the clinical usability of widely used hydrofibre dressings. The burns healed within an expected period of time, and did not undergo any infectious processes. Based on the results of this pilot study, the chitosan-based silver dressing is deserving of further study as an alternative to traditional burn dressings