Bit error rate performance enhancement of a retrodirective array over a conventional fixed beam array in a dynamic multipath environment

In this paper, we provide experimental evidence to show that enhanced bit error rate (BER) performance is possible using a retrodirective array operating in a dynamically varying multipath environment. The operation of such a system will be compared to that obtained by a conventional nonretrodirective array. The ability of the array to recover amplitude shift keyed encoded data transmitted from a remote location whose position is not known a priori is described. In addition, its ability to retransmit data inserted at the retrodirective array back to a spatially remote beacon location whose position is also not known beforehand is also demonstrated. Comparison with an equivalent conventional fixed beam antenna array utilizing an identical radiating aperture arrangement to that of the retrodirective array are given. These show that the retrodirective array can effectively exploit the presence of time varying multipath in order to give significant reductions in BER over what can be otherwise achieved. Additionally, the retrodirective system is shown to be able to deliver low BER regardless of whether line of sight is present or absent.

The Evolving Role of the UNCHR: Should the Conventional Role of UNHCR Be Expanded?

This paper focuses on the question of whether the UNHCR should be governed only by its original 1950 mandate to provide international protection to refugees or should its role be re-defined in order to cover those who are not refugees, yet in refugee-like conditions. The purpose of this study is to scrutinize what rights UNHCR already possesses with regards to its newly-evolved tasks and what sort of legal framework is required today.

Computer-assisted pathological immunohistochemistry scoring is more time-effective than conventional scoring, but provides no analytical advantage

Computer-assisted pathological immunohistochemistry scoring is more time-effective than conventional scoring, but provides no analytical advantage

Conventional 3D staging PET/CT in CT simulation for lung cancer: impact of rigid and deformable target volume alignments for radiotherapy treatment planning

Objective: Positron emission tomography (PET)/CT scans can improve target definition in radiotherapy for non-small cell lung cancer (NSCLC). As staging PET/CT scans are increasingly available, we evaluated different methods for co-registration of staging PET/CT data to radiotherapy simulation (RTP) scans.

Methods: 10 patients underwent staging PET/CT followed by RTP PET/CT. On both scans, gross tumour volumes (GTVs) were delineated using CT (GTVCT) and PET display settings. Four PET-based contours (manual delineation, two threshold methods and a source-to-background ratio method) were delineated. The CT component of the staging scan was co-registered using both rigid and deformable techniques to the CT component of RTP PET/CT. Subsequently rigid registration and deformation warps were used to transfer PET and CT contours from the staging scan to the RTP scan. Dice’s similarity coefficient (DSC) was used to assess the registration accuracy of staging-based GTVs following both registration methods with the GTVs delineated on the RTP PET/CT scan.

Results: When the GTVCT delineated on the staging scan after both rigid registration and deformation was compared with the GTVCT on the RTP scan, a significant improvement in overlap (registration) using deformation was observed (mean DSC 0.66 for rigid registration and 0.82 for deformable registration, p50.008). A similar comparison for PET contours revealed no significant improvement in overlap with the use of deformable registration.

Conclusions: No consistent improvements in similarity measures were observed when deformable registration was used for transferring PET-based contours from a staging PET/CT. This suggests that currently the use of rigid registration remains the most appropriate method for RTP in NSCLC.

Integrated care: utilisation of complementary and alternative medicine within a conventional cancer treatment centre

Objectives: To estimate the proportion of cancer outpatients who visit a Complementary and Alternative Medicine (CAM) unit that is located within a conventional cancer treatment centre; to compare the characteristics of CAM unit visitors with those of all outpatients; to monitor the demand for 20 CAM therapies delivered by professionals, and the use of the CAM unit for waiting, gathering information and informal support from volunteer staff.

Design: Prospective, observational, over a six month period.

Setting: CAM unit within a NHS cancer treatment centre.

Main outcome measures: Utilisation of the CAM unit for 20 complementary therapies, and for waiting, gathering information, informal support; characteristics of CAM users compared with those of all cancer outpatients attending the cancer centre; predictors of CAM therapy use and frequent use.

Results: 761 (95% of those approached) people were recruited, 498 (65.4%) cancer patients, 202 (26.5%) relatives, 37 (4.8%) friends/carers, 24 (3.2%) staff. Women predominated (n = 560, 73.6%). Of all outpatients attending the cancer centre, 498 (15.8%) visited the CAM unit, 290 (9.2%) accessed therapies. Compared to all outpatients, those visiting the CAM unit were: younger (mean 63.7 vs. 58.4 years), more likely to be female (57.9% vs. 78.7%), have breast (14.8% vs. 51.9%), gynaecological (5.0% vs. 9.1%) cancer, live in local postal district (57.3% vs. 61.6%). Significant predictors of therapy use and frequent visits were being a patient, female, higher education, living closer to the cancer centre.

Conclusions: Despite easy access to CAM therapies, a relatively small number of people regularly used them, whilst a larger number selectively tried a few. The integrated CAM unit meets a demand for information and informal support. The findings inform emerging policy on integrating CAM and conventional cancer treatment to address psychosocial needs of people with cancer. More research is needed on why people do not use integrated CAM services and how charges affect demand. © 2008.

DETERMINATION OF THE CONCENTRATIONS OF THE STEROIDS ESTRADIOL, PROGESTERONE AND TESTOSTERONE IN BOVINE SERA - COMPARISON OF COMMERCIAL DISSOCIATION ENHANCED LANTHANIDE FLUORESCENCE IMMUNOASSAY KITS WITH CONVENTIONAL RADIO AND ENZYME IMMUNOASSAYS

The performance of three conventional enzyme and radioimmunoassays routinely used to detect residues of anabolic steroids in cattle sera were compared with dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) kits designed for the hospital market. Slight modifications to the kit reagents were required for the analysis of bovine sera. Owing to the large sample volumes used in conventional assays, detection limits were generally better than those obtained with DELFIA kits, however, assay reproducibility was enhanced using the DELFIA technology. Comparison of sera obtained from cattle implanted with anabolic steroids revealed a good correlation between alternate methods (r(2) from 0.91 to 0.97). The DELFIA kits offer a faster method for measuring estradiol, progesterone and testosterone with adequate sensitivity and in a safer environment than that encountered using radioimmunoassays.