A Study Of Meteor Burst Channel Characteristics

To be accepted as a viable competitor for long distance communication, it remains to be demonstrated that meteor burst systems possess the potential to support reasonable throughput at agreeable costs. Using measurements from an existing meteor burst link between London and Ottawa, estimates of the path loss, flight-time, waiting time and burst duration were obtained. These results demonstrated that by employing modest equipment, communication could be maintained with an average waiting time of 3.5 minutes and an average transmission time or burst duration 0.5 seconds. By using these parameters and assuming a transmission rate of 4800 bps, the average throughput for this link was estimated to be 11.4 bps. While this throughput may be adequate for applications having low data volumes such as remote monitoring and vehicle tracking, improvements are achievable through increases in transmitter power, antenna gains and data transmission rate. To date, however, little research has been undertaken to assess the effect of potential bandwidth limitations (if any) which may restrict the signaling rate that can be supported by the link. An investigation of these impairments was carried out using an instrument that was specifically designed to probe the multipath nature of the meteor burst channel. These measurements revealed that in the majority of instances only a single path exists between the transmitter and receiver and consequently, serious impairments arising from multipath interference appear to be relatively infrequent. In some rare instances, however, as many as four such paths have been observed. Delay spread measurements were found to confirm the presence of multipath interference for which the statistics reveal that in 90% of all observations the delay spread is below 100 ns. Based on these statistics and observations to date, it is likely that data rates ranging from several hundred kbps to perhaps 1 Mbps can be supported by the meteor burst channel

The effects of night wear orthokeratology lenses on central cornela thickness

Purpose: This study was performed to determine the effectiveness and safety of Night Move™ orthokeratology lenses and to examine their effects on central corneal thickness. Methods: Ten subjects (20 eyes) with myopia less than 5D and with the rule astigmatism less than 1.50D were fitted with the Night Move™ orthokeratology lenses. The lenses were worn at night for a period of 30 days. Subjects were examined prior to the study, at 1 day, 7 days and 30 days. Unaided visual acuity, refractive error, keratometric readings, intraocular pressure and central pachymetry measurements were determined at each visit. Results: All eyes reached unaided visual acuities of at least 20/40 with 90% reaching 20/20 or better. Mean refractive error demonstrated a decrease in myopia from -2.26D to -0.04D at 30 days. The mean steep K was reduced 1.46D at 30 days. The mean decrease in central corneal thickness was 0.022mm after 30 nights of lens wear. Mild cases of epithelial staining were seen in 2 eyes at 1 day and 7 days. No staining was seen after 7 days. All other ocular health was unremarkable throughout the study. Conclusions: Changes in mean keratometric readings and mean refractive error do not explain the acuities achieved by the subjects in the study. A decrease in central corneal thickness provides the additional power to allow subjects to achieve optimum visual acuity. The change in corneal thickness is small compared to photorefractive surgeries and provides a safer alternative maintaining greater corneal integrity

National Indigenous Palliative Care Needs Study

This study involved extensive consultation with the community to identify the needs of Aboriginal and Torres Strait Islander peoples in palliative care

Designing whole-systems commissioning: lessons from the English experience

The paucity of formal evidence, allied to the requirement for strategies that are sensitive to local history and context, means that a ‘blueprint’ for successful strategic commissioning is not currently available for adoption. We are therefore confined to proposing ‘design principles’ for those seeking to embark upon a transition towards a whole systems approach to strategic commissioning. People and relationships are of critical importance all the way through the chain from strategic commissioning to micro-commissioning. Most crucially, experience suggests that structural solutions alone cannot deliver effective relationships and will not be effective when relationships are neglected. The need to ensure staff, partner and political buy-in suggests that relationship management and consensus-building are an integral component of the leadership role in moving toward strategic commissioning. As with any major re-organisation, the move to strategic commissioning is essentially a change management initiative and therefore will stand or fall according to whether it adheres to good practice in the change management process. Central to this, and to achieving commissioning outcomes, is the requirement for meaningful service user and public engagement. Effective commissioning emphasizes individual capabilities as well as needs, and community assets as well as deficits and problems. Adoption of strategic commissioning approaches is still at the developmental and learning stage and arguably all structural arrangements should be regarded as transitional

Was the NOAA Panel Correct About Contingent Valuation?

The past few years have seen a highly charged debate about whether contingent valuation (CV) surveys can provide valid economic measures of people's values for environmental resources. In an effort to appraise the validity of CV measures of economic value, a distinguished panel of social scientists, chaired by two Nobel laureates, was established by NOAA, to critically evaluate the validity of CV measures of nonuse value. The Panel provided an extensive set of guidelines for CV survey construction, administration, and analysis, and distinguished a subset of items from their guidelines for special emphasis and described them as burden of proof requirements. Of particular interest was the Panel's requirement that CV surveys demonstrate "responsiveness to the scope of the environmental insult." That demonstration has come to be called a scope test. The paper reports the findings from the first CV study that adheres to the NOAA Panel's guidelines and includes a formal scope test.

Review Essay: Emplacement and everyday use of medications in domestic dwellings

To extend knowledge of relationships between people and domestic settings in the context of medication use, we conducted fieldwork in twenty households in New Zealand. These households contained a range of ‘medicative’ forms, including prescription drugs, traditional remedies, dietary supplements and enhanced foods. The location and use of these substances within domestic dwellings speaks to processes of emplacement and identity in the creation of spaces for care. Our analysis contributes to current understandings of the ways in which objects from ‘outside’ the home come to be woven into relationships, identities and meanings ‘inside’ the home. We demonstrate that, as well as being pharmacological objects, medications are complex, socially embedded objects with histories and memories that are ingrained within contemporary relationships of care and home-making practices

SSCR Scoping Review: The role of the third sector in delivering social care

Third sector providers have been important in the delivery of social care services for some time. Long before the advent of the ‘contract culture’ that started to emerge in the 1980s, third sector organisations have been involved in the delivery of what we would today define as social care. But this role is changing as the personalisation agenda takes hold and there is a push for closer integration between health and social care services within a context of constrained financial resources

Referendum Design and Contingent Valuation: The NOAA Panel's No-Vote Recommendation

In 1992 the National Oceanic and Atmospheric Administration (NOAA) convened a panel of prominent social scientists to assess the reliability of natural resource damage estimates derived from contingent valuation (CV). The product of the Panel's deliberations was a report that laid out a set of recommended guidelines for CV survey design, administration, and data analysis. One of the Panel's recommendations was that CV surveys should employ a referendum approach. This method describes a choice mechanism that asks each respondent how they would vote if faced with a particular program and the prospect of paying for the program through some means, such as higher taxes. The Panel also recommended that CV referendum questions which commonly use only "for" or "against" answers should be expanded to explicitly offer an "I would-not-vote" response. The purpose of this paper is to consider the effects of such a "would-not-vote" option. In developing the test, we followed the important elements of the NOAA Panel guidelines for the design and administration of a CV survey and use what was acknowledged(by the Panel) as the most carefully developed CV questionnaire to that time, that is, the State of Alaska's study of the Exxon Valdez oil spill. Our findings suggest that when those selecting the "would-not-vote" response are treated as having voted "against" the offered program, offering the option does not alter: (a) the distribution of "for" and "against" responses, (b) the estimates of WTP derived from these choices, or (c) the construct validity of the results.