Unethical aspects of homeopathic dentistry

In the last year there has been a great deal of public debate about homeopathy, the system of alternative medicine whose main principles are that like cures like and that potency increases relative to dilution. The House of Commons Select Committee on Science and Technology concluded in November 2009 that there is no evidence base for homeopathy, and agreed with some academic commentators that homeopathy should not be funded by the NHS. While homeopathic doctors and hospitals are quite commonplace, some might be surprised to learn that there are also many homeopathic dentists practising in the UK. This paper examines the statements made by several organisations on behalf of homeopathic dentistry and suggests that they are not entirely ethical and may be in breach of various professional guidelines

Activation of WNT and BMP signaling in adult human articular cartilage following mechanical injury

Peer reviewedPublisher PD

Chromatic dispersion monitoring for high-speed WDM systems using two-photon absorption in a semiconductor microcavity

This paper presents a theoretical and experimental investigation into the use of a two-photon absorption (TPA) photodetector for use in chromatic dispersion (CD) monitoring in high-speed, WDM network. In order to overcome the inefficiency associated with the nonlinear optical-to-electrical TPA process, a microcavity structure is employed. An interesting feature of such a solution is the fact that the microcavity enhances only a narrow wavelength range determined by device design and angle at which the signal enters the device. Thus, a single device can be used to monitor a number of different wavelength channels without the need for additional external filters. When using a nonlinear photodetector, the photocurrent generated for Gaussian pulses is inversely related to the pulsewidth. However, when using a microcavity structure, the cavity bandwidth also needs to be considered, as does the shape of the optical pulses incident on the device. Simulation results are presented for a variety of cavity bandwidths, pulse shapes and durations, and spacing between adjacent wavelength channels. These results are verified experimental using a microcavity with a bandwidth of 260 GHz (2.1 nm) at normal incident angle, with the incident signal comprising of two wavelength channels separated by 1.25 THz (10 nm), each operating at an aggregate data rate of 160 Gb/s. The results demonstrate the applicability of the presented technique to monitor accumulated dispersion fluctuations in a range of 3 ps/nm for 160 Gb/s RZ data channel

Prescribing trends of gabapentin, pregabalin and oxycodone; a secondary analysis of primary care prescribing patterns in England

Background The risk of iatrogenic harm from prescription drug use, misuse and abuse of drugs such as gabapentin, pregabalin and oxycodone is substantial. In recent years, deaths associated with these drugs in England have increased. Aims To characterise general practice prescribing trends for gabapentin, pregabalin and oxycodone – termed dependence forming medicines (DFM) – in England and describe potential drivers of unwarranted variation. Design and Setting This study is a retrospective secondary analysis of open source, publicly available government data from various sources pertaining to primary care demographics and prescriptions. Methods This study used five consecutive years (April 2013 – March 2018) of aggregate data to investigate longitudinal trends of prescribing and variation in prescribing trends at practice and clinical commissioning group (CCG) level. Results Annual prescriptions of gabapentin, pregabalin and oxycodone have increased each year over the period. Variation in prescribing trends were associated with GP practice deprivation quintile, where the most deprived GP practices prescribe 313% (p<0.001) and 238% (p<0.001) greater volumes of gabapentin and pregabalin per person than practices in the least deprived quintile. The highest prescribing CCGs of each of these drugs were predominantly in northern and eastern regions of England. Conclusions Substantial increases in gabapentin, pregabalin and oxycodone prescriptions are concerning and will increase iatrogenic harm from drug-related morbidity and mortality. More research is needed to understand the large variation in prescribing between general practices; and to develop and implement interventions to reduce unwarranted variation and increase the appropriateness of prescribing of these drugs

All-optical pulse processing for advanced photonic communication system

This paper investigates the use of a two-photon absorption photodetector for high speed processing of ultrashort optical pulses in advanced photonic communication systems. Specifically the paper describes how the two-photon absorption photodetector maybe employed for chromatic dispersion monitoring in high-speed, wavelength division multiplexed networks, and also for reducing multiple access interference noise in an optical code division multiplexed system

Two-photon-absorption-based OSNR monitor for NRZ-PSK transmission systems

A two-photon absorption microcavity-based technique for monitoring in-band optical signal-to-noise ratio (OSNR) in nonreturn-to-zero phase-shift-keying systems is presented. Experiments using a 10-Gb/s differential phase-shift-keying system showed that accurate measurements ( 1 dB) were possible for OSNRs in excess of 20 dB

The 15-43 GHz parsec-scale circular polarization of 41 active galactic nuclei

We present the results of parsec-scale circular-polarization measurements based on Very Long Baseline Array data for a number of radio-bright, core-dominated active galactic nuclei obtained simultaneously at 15, 22 and 43 GHz. The degrees of circular polarization m(c) for the Very Long Baseline Interferometry (VLBI) core region at 15 GHz are similar to the values reported earlier at this wavelength, with typical values of a few tenths of a per cent. We find that mc as often rises as falls with increasing frequency between 15 and 22 GHz, while the degree of circular polarization at 43 GHz is in all cases higher than at 22 and 15 GHz. This behaviour seems contrary to expectations, since the degree of circular polarization from both synchrotron radiation and the Faraday conversion of linear to circular polarization - the two main mechanisms considered thus far in the literature - should decrease towards higher frequencies if the source is homogeneous. The increase in mc at 43 GHz may be due to the presence of regions of both positive and negative circular polarization with different frequency dependences ( but decreasing with increasing frequency) on small scales within the core region; alternatively, it may be associated with the intrinsic inhomogeneity of a Blandford-Konigl like jet. In several objects, the detected circular polarization appears to be near, but not coincident with, the core, although further observations are needed to confirm this. We find several cases of changes in sign with frequency, most often between 22 and 43 GHz. We find tentative evidence for transverse structure in the circular polarization of 1055+018 and 1334-127, that is consistent with their being generated by either the synchrotron mechanism or the Faraday conversion in a helical magnetic field. Our results confirm the earlier finding that the sign of the circular polarization at a given observing frequency is generally consistent across epochs separated by several years or more, suggesting stability of the magnetic-field orientation in the innermost jets