Dynamic FOV visible light communications receiver for dense optical networks

This study explores how the field-of-view (FOV) of a visible light communications (VLCs) receiver can be manipulated to realise the best signal-to-noise ratio (SNR) while supporting device mobility and optimal access point (AP) selection. The authors propose a dynamic FOV receiver that changes its aperture according to receiver velocity, location, and device orientation. The D-FOV technique is evaluated through modelling, analysis, and experimentation in an indoor environment comprised of 15 VLC APs. The proposed approach is also realised as an algorithm that is studied through analysis and simulation. The results of the study indicate the efficacy of the approach including a 3X increase in predicted SNR over static FOV approaches based on measured received signal strength in the testbed. Additionally, the collected data reveal that D-FOV increases effectiveness in the presence of noise. Finally, the study describes the tradeoffs among the number of VLC sources, FOV, user device velocity, and SNR as a performance metric.Accepted manuscrip

The perils of proxy outcomes in evidence-based medicine: the case of recombinant factor VIIa.

There is currently a major controversy surrounding the off-label use of recombinant activated Factor VII (rFVIIa). The literature offers at best inconclusive support for its use in the management of bleeding in any situation other than in patients with Factor VII deficiency or hemophilia A or B with antibodies to factor VIII or factor IX respectively. This evidence has not, however, slowed the growth in off-label prescribing of rFVIIa in other situations including intracranial hemorrhage, cardiac surgery, trauma, transplantation and prostatectomy. We argue that the controversy surrounding such off-label use of rFVIIa stems in part from different understandings of the purposes and methods of evidence-based medicine (EBM) - in particular the use of gross, proxy outcomes such as mortality to determine the effectiveness of an intervention. We then argue that clinical impression and expert opinion should not be dismissed outright on the basis of inconclusive evidence of ineffectiveness. Those who advocate its continued use, however, have a responsibility to demonstrate the benefits that may be missed in current manifestations of EBM. We suggest that the only justified verdict in the case of rFVIIa is currently 'Not Proven'. Keywords Clinical experience, evidence, evidence-based medicine, outcomes, proxy outcomes, recombinant Factor VIIaNHMR

Return of the Memento Mori: imaging death in public health.

Death has always held a morbid fascination for humans. Indeed, awareness of one’s own mortality may well be one of the defining features of the ‘human condition’ – symbols of death appearing in most civilizations since artefacts have been made. The Latin phrase memento mori, meaning literally ‘remember to die’, encapsulates a rich and varied artistic tradition, dating back to the Middle Ages, of figuring death by symbolizing its literal processes and remainders. From the decomposed effigies of 15th-century ‘cadaver tombs’, to the humorous medieval iconography of the skeletal danse macabre, the works of this genre draw on the destructive physical changes that are a part of our understanding of death. Prolific within its morbid imagery are the use of skull, skeleton and verminous or rotting flesh as ‘trope’ or symbol of the processes that eventually take away the person who lived, and who was once like us. At the height of its popularity between the 16th and 18th centuries, Church walls, tombs, jewellery, paintings, and so on frequently depicted death and decay. The entreaty to ‘remember’ death in memento mori was more than simply a call for ‘therapeutic contemplation’1 or the banal acceptance of the imminence of death; it was a call to piety, to conformity. Damnation would be added to death if the individual transgressed the rules of Catholic doctrine, such that scholars often trace a continuity between the motives of memento mori, and the biblical injunction: ‘Whatsoever thou takest in hand, remember the end, and thou shalt never do amiss’ (Ecclesiasticus 7:36).2 Even within the iconophobic Protestantism of the post-Reformation era, the memento mori trope persisted as a privileged mode of pious warning. In the visually secular effigy monuments of the Elizabethan gentry, inscriptions urging the reader to ‘(r)emember the last things and…not sin again’ signified that death would come to everyone – but only spiritual public health would reduce the risk of eternal punishment and separation from God.3 The memento mori trope survives into the present day, albeit in differing locations. Loosely discernible in the ‘corpse chic’ of contemporary haute couture, and entrenched within the aesthetics of punk and gothic subcultures, the skull and skeleton loom large as Western symbols of cultural rebellion.4 Similarly, the fully enfleshed ‘corpse’ continues to haunt the zone of 2 | P a g e contemporary representation – saturating the realm of Hollywood film and ‘hard news’ reportage alike, and asserting its dominance in forensics-inspired television programmes such as CSI. Representing death, it would seem, has never been more popular. Indeed, depictions of death have emerged as ‘mainstream advertising strategy’4 – their gore and horror satisfying a perverse voyeurism that many would attribute to the alienating effects of mass media saturation. While the ‘pornography’ of suffering5 in contemporary culture appears to have little in common with classical memento mori, if one looks closely, certain elements particular to this once-spiritual genre of death depiction can be unearthed, most notably in the secular arena of public health

Return of the Memento Mori: imaging death in public health.

Death has always held a morbid fascination for humans. Indeed, awareness of one’s own mortality may well be one of the defining features of the ‘human condition’ – symbols of death appearing in most civilizations since artefacts have been made. The Latin phrase memento mori, meaning literally ‘remember to die’, encapsulates a rich and varied artistic tradition, dating back to the Middle Ages, of figuring death by symbolizing its literal processes and remainders. From the decomposed effigies of 15th-century ‘cadaver tombs’, to the humorous medieval iconography of the skeletal danse macabre, the works of this genre draw on the destructive physical changes that are a part of our understanding of death. Prolific within its morbid imagery are the use of skull, skeleton and verminous or rotting flesh as ‘trope’ or symbol of the processes that eventually take away the person who lived, and who was once like us. At the height of its popularity between the 16th and 18th centuries, Church walls, tombs, jewellery, paintings, and so on frequently depicted death and decay. The entreaty to ‘remember’ death in memento mori was more than simply a call for ‘therapeutic contemplation’1 or the banal acceptance of the imminence of death; it was a call to piety, to conformity. Damnation would be added to death if the individual transgressed the rules of Catholic doctrine, such that scholars often trace a continuity between the motives of memento mori, and the biblical injunction: ‘Whatsoever thou takest in hand, remember the end, and thou shalt never do amiss’ (Ecclesiasticus 7:36).2 Even within the iconophobic Protestantism of the post-Reformation era, the memento mori trope persisted as a privileged mode of pious warning. In the visually secular effigy monuments of the Elizabethan gentry, inscriptions urging the reader to ‘(r)emember the last things and…not sin again’ signified that death would come to everyone – but only spiritual public health would reduce the risk of eternal punishment and separation from God.3 The memento mori trope survives into the present day, albeit in differing locations. Loosely discernible in the ‘corpse chic’ of contemporary haute couture, and entrenched within the aesthetics of punk and gothic subcultures, the skull and skeleton loom large as Western symbols of cultural rebellion.4 Similarly, the fully enfleshed ‘corpse’ continues to haunt the zone of 2 | P a g e contemporary representation – saturating the realm of Hollywood film and ‘hard news’ reportage alike, and asserting its dominance in forensics-inspired television programmes such as CSI. Representing death, it would seem, has never been more popular. Indeed, depictions of death have emerged as ‘mainstream advertising strategy’4 – their gore and horror satisfying a perverse voyeurism that many would attribute to the alienating effects of mass media saturation. While the ‘pornography’ of suffering5 in contemporary culture appears to have little in common with classical memento mori, if one looks closely, certain elements particular to this once-spiritual genre of death depiction can be unearthed, most notably in the secular arena of public health

Marginalizing experience: A critical analysis of public discourse surrounding stem cell research in Australia (2005-6).

Over the past decade, stem cell science has generated considerable public and political debate. These debates tend to focus on issues concerning the protection of nascent human life and the need to generate medical and therapeutic treatments for the sick and vulnerable. The framing of the public debate around these issues not only dichotomises and oversimplifies the issues at stake, but tends to marginalise certain types of voices, such as the women who donate their eggs and/or embryos to stem cell research and the patients who might benefit from its potential clinical outcomes. This paper draws on empirical research conducted on a recent stem cell policy episode in Australia. From the qualitative examination of 109 newspaper opinion editorials and twenty-three in-depth interviews, it is argued that these voices are marginalised because they are based on discourses that have less epistemological status in public debate. Our results suggest that the personal experiences of women and patients are marginalised by the alliances that form between more powerful discourse communities that use science as a source of authority and legitimation. It is argued that members of these communities establish legitimacy and assert authority in public debate by discursively deploying science in claims that marginalise other epistemologies. Implications are discussed along with suggestions for a more enriched and inclusive public debate. Keywords Stem cellsCloningBioethicsPublic polic

Further detections of OH masers in carbon stars with silicate features

A sample of J-type carbon stars was searched for OH maser emission. The new detection of three OH lines towards two silicate carbon stars is reported. In V778 Cyg, previously known as the main-lines (1665 and 1667 MHz) maser source, the satellite 1612 MHz emission was discovered while in NSV 2814 the main OH lines were detected. The presence of OH maser lines confirms the former suggestion that oxygen-rich material is located in the vicinity ($\approx$ $10^{15-16}$ cm) of silicate carbon stars.Comment: LaTeX2e, 4 pages with 2 figure

Shadow Pricing and Macroeconomic Analysis: Some Illustrations from Pakistan

Shadow prices are being used increasingly in the economic analysis of projects. The purpose of this paper, however, is to argue that shadow prices are equally relevant for certain types of analysis at the macro-economic level. In theory, macroeconomic issues can be properly analyzed, if at all, only in general equilibrium frame• work. Quantification then requires the solution of an appropriate model. But, estimable general equilibrium models can seldom include many variables, and the level of aggregation must remain high. They are general only in the very partial sense of simultaneous solution of a limited set of aggregated endogenous variables. On the other hand, some of the issues addressed by shadow pricing involve quite disaggregated variables, and, of course, project analysis itself often requires very detailed estimations

Induction of dc voltage, proportional to the persistent current, by external ac current on system of inhomogeneous superconducting loops

A dc voltage induced by an external ac current is observed in system of asymmetric mesoscopic superconducting loops. The value and sign of this dc voltage, like the one of the persistent current, depend in a periodical way on a magnetic field with period corresponded to the flux quantum within the loop. The amplitude of the oscillations does not depend on the frequency of the external ac current (in the investigated region 100 Hz - 1 MHz) and depends on its amplitude. The latter dependence is not monotonous. The observed phenomenon of rectification is interpreted as a consequence of a dynamic resistive state induced by superposition of the external current and the persistent current. It is shown that the dc voltage can be added in system of loops connected in series: the dc voltage oscillations with amplitude up to 0.00001 V were observed in single loop, up to 0.00004 V in a system of 3 loops and up to 0.0003 V in a system of 20 loops.Comment: 5 pages, 6 figure