Photonically referenced extremely stable oscillator.

Due to their low phase noise at high carrier frequencies, photonic microwave oscillators are continuously expanding their application areas including digital signal processing, telecommunications, radio astronomy, and RADAR and LIDAR systems. Currently, the lowest noise photonic oscillators rely on traditional optical frequency combs with multiple stabilization loops that incorporate large vacuum components and complex optoelectronic configurations. Hence, the resulting systems are not only challenging to operate but also expensive to maintain. Here, we introduce a significantly simpler solution: a Photonically Referenced Extremely STable Oscillator (PRESTO). PRESTO requires only three key components: a femtosecond laser, a fiber delay element, and a pulse timing detector. The generated microwave at 10 GHz has phase noise levels of -125, -145, and <-160 dBc/Hz at 1, 10, and >100 kHz, respectively, with an integrated timing jitter of only 2 fs root mean square (RMS) over [100 Hz-1 MHz]. This approach offers a reliable solution for simplifying and downsizing photonic oscillators while delivering high performance.

Detection of a local Mycobacterium bovis reservoir using cattle surveillance data.

The incidence of bovine tuberculosis (TB, caused by Mycobacterium bovis) in cattle has been associated with TB in badgers (Meles meles) in parts of England. The aim was to identify badger-associated M. bovis reservoirs in the Edge Area, between the High- and Low-Risk Areas for cattle TB. Data from badger TB surveys were sparse. Therefore, a definition for a local M. bovis reservoir potentially shared by cattle and badgers was developed using cattle TB surveillance data. The performance of the definition was estimated through Latent Class Analysis using badger TB survey data. Spatial units (25 km2 ) in the Edge Area were classified as having a reservoir if they had (i) at least one TB incident in at least three of the previous 7 years, (ii) at least one TB incident in a cattle herd confirmed by post-mortem tests as due to M. bovis infection and not attributable to cattle movements in the previous 2 years and (iii) more confirmed TB incidents than un-confirmed in the previous 2 years. Approximately 20% of the Edge Area was classified as having a local M. bovis reservoir using the cattle-based definition. Assuming 15% TB prevalence in Edge Area badgers, sensitivity for the local M. bovis reservoir definition varied from 25.7% [95% credible interval (CrI): 10.7%-85.1%] to 64.8% (95% CrI: 48.1%-88.0%). Specificity was 91.9% (CrI: 83.6%-97.4%). Over 90% of the local reservoir was in stable endemic TB areas identified through previous work and its spatial distribution was largely consistent with local veterinary knowledge. Uncertainty in the reservoir spatial distribution was explored through its recalculation in spatial units shifted in different directions. We recommend that the definition is re-evaluated as further data on badger infection with M. bovis become available.

Cat-to-Human Transmission of Mycobacterium bovis, United Kingdom.

Human infection with Mycobacterium bovis is reported infrequently in the United Kingdom. Most cases involve previous consumption of unpasteurized milk. We report a rare occurrence of 2 incidents of cat-to-human transmission of M. bovis during a cluster of infection in cats.

Bovine tuberculosis in working foxhounds: lessons learned from a complex public health investigation.

In 2017, Public Health England South East Health Protection Team (HPT) were involved in the management of an outbreak of Mycobacterium bovis (the causative agent of bovine tuberculosis) in a pack of working foxhounds. This paper summarises the actions taken by the team in managing the public health aspects of the outbreak, and lessons learned to improve the management of future potential outbreaks. A literature search was conducted to identify relevant publications on M. bovis. Clinical notes from the Public Health England (PHE) health protection database were reviewed and key points extracted. Animal and public health stakeholders involved in the management of the situation provided further evidence through unstructured interviews and personal communications. The PHE South East team initially provided 'inform and advise' letters to human contacts whilst awaiting laboratory confirmation to identify the infectious agent. Once M. bovis had been confirmed in the hounds, an in-depth risk assessment was conducted, and contacts were stratified in to risk pools. Eleven out of 20 exposed persons with the greatest risk of exposure were recommended to attend TB screening and one tested positive, but had no evidence of active TB infection. The number of human contacts working with foxhound packs can be large and varied. HPTs should undertake a comprehensive risk assessment of all potential routes of exposure, involve all other relevant stakeholders from an early stage and undertake regular risk assessments. Current guidance should be revised to account for the unique risks to human health posed by exposure to infected working dogs.

An outbreak of tuberculosis due to Mycobacterium bovis infection in a pack of English Foxhounds (2016-2017).

Mycobacterium bovis can cause tuberculosis (TB) in social mammals including lions, cattle and man, but canine infections are considered rare. In 2016/17 we investigated a M. bovis TB outbreak in a pack of approximately 180 Foxhounds within the bovine TB Edge Area of England. We employed a combination of immunological tests including an interferon gamma release assay (IGRA) and a serological assay (DPP VetTB, Chembio). Test-positive hounds were euthanased and subjected to post-mortem examination (PME). Overall 164 hounds were tested; 97 (59%) responded positively to at least one test. Eighty-five (52%) dogs responded to M. bovis antigens by IGRA while only 21 (12.9%) had detectable serological responses. At PME three hounds (3.1%) had visible lesions (VL) due to M. bovis infection, later confirmed by culture. Samples from 24 non-VL hounds were cultured and M. bovis infection was confirmed in a further three hounds (11%). This study is the first investigation and report of an outbreak of M. bovis TB in a canine species. We establish that, in principle, diagnostic tests used for identifying infected individuals of other species can effectively be used in the dog. Further work is urgently needed to establish the sensitivity and specificity of the testing approach used in this study for future clinical application.

Fiber-coupled balanced optical cross-correlator using PPKTP waveguides.

We present a fiber-coupled balanced optical cross-correlator using waveguides in periodically-poled KTiOPO(4) (PPKTP). The normalized conversion efficiency of the waveguide device is measured to be η(0) = 1.02% / [W · cm(2)], which agrees well with theory and simulation. This result represents an expected improvement of a factor of 20 over previous bulk-optic devices. The sensitivity of the cross-correlator is characterized and shown to be comparable to the free-space bulk-optic version, with the potential for significant performance enhancements in the future.

Ethical review of research on human subjects at Unilever: reflections on governance.

This article considers the process of ethical review of research on human subjects at a very large multinational consumer products company. The commercial context of this research throws up unique challenges and opportunities that make the ethics of the process of oversight distinct from mainstream medical research. Reflection on the justification of governance processes sheds important, contrasting light on the ethics of governance of other forms and context of research.

Facial aesthetics: babies prefer attractiveness to symmetry.

The visual preferences of human infants for faces that varied in their attractiveness and in their symmetry about the midline were explored. The aim was to establish whether infants' visual preference for attractive faces may be mediated by the vertical symmetry of the face. Chimeric faces, made from photographs of attractive and unattractive female faces, were produced by computer graphics. Babies looked longer at normal and at chimeric attractive faces than at normal and at chimeric unattractive faces. There were no developmental differences between the younger and older infants: all preferred to look at the attractive faces. Infants as young as 4 months showed similarity with adults in the 'aesthetic perception' of attractiveness and this preference was not based on the vertical symmetry of the face.

High-quality fiber-optic polarization entanglement distribution at 1.3 microm telecom wavelength.

We demonstrate high-quality distribution of 1.3 microm polarization-entangled photons generated from a fiber-coupled periodically poled KTiOPO(4) waveguide over 200 m fiber-optic cables. Time-multiplexed measurements with a 19% efficient superconducting nanowire single-photon detector at the remote location show a detected flux of 5.8 pairs/s at a pump power of 25 microW and an average two-photon quantum-interference visibility of 97.7% without subtraction of accidentals.

Guided wave optics in periodically poled KTP: quadratic nonlinearity and prospects for attosecond jitter characterization.

For the first time to our knowledge, continuous nonsegmented channel waveguides in periodically poled KTiOPO(4) with guided orthogonal polarizations are used to demonstrate type II background-free second harmonic generation in the telecom band with 1.6%/(W cm(2)) normalized conversion efficiency. This constitutes a 90-fold improvement in aggregate conversion efficiency over its free space counterpart. Simulations show that the guided wave device should enable the measurement of timing fluctuations of optical pulse trains at the attosecond level in an optical cross correlation scheme.

A genetic linkage map of Venturia inaequalis, the causal agent of apple scab.

BACKGROUND: Venturia inaequalis is an economically-important disease of apple causing annual epidemics of scab worldwide. The pathogen is a heterothallic ascomycete with an annual cycle of sexual reproduction on infected apple leaf litter, followed by several cycles of asexual reproduction during the apple growing season. Current disease control is achieved mainly through scheduled applications of fungicides. Genetic linkage maps are essential for studying genome structure and organisation, and are a valuable tool for identifying the location of genes controlling important traits of interest such as avirulence, host specificity and mating type in V. inaequalis. In this study, we performed a wide cross under in vitro conditions between an isolate of V. inaequalis from China and one from the UK to obtain a genetically diverse mapping population of ascospore progeny isolates and produced a map using AFLP and microsatellite (SSR) markers. FINDINGS: Eighty-three progeny were obtained from the cross between isolates C0154 (China) x 01/213 (UK). The progeny was screened with 18 AFLP primer combinations and 31 SSRs, and scored for the mating type locus MAT. A linkage map was constructed consisting of 294 markers (283 AFLPs, ten SSRs and the MAT locus), spanning eleven linkage groups and with a total map length of 1106 cM. The length of individual linkage groups ranged from 30.4 cM (Vi-11) to 166 cM (Vi-1). The number of molecular markers per linkage group ranged from 7 on Vi-11 to 48 on Vi-3; the average distance between two loci within each group varied from 2.4 cM (Vi-4) to 7.5 cM (Vi-9). The maximum map length between two markers within a linkage group was 15.8 cM. The MAT locus was mapped to a small linkage group and was tightly linked to two AFLP markers. The map presented is over four times longer than the previously published map of V. inaequalis which had a total genetic distance of just 270 cM. CONCLUSION: A genetic linkage map is an important tool for investigating the genetics of important traits in V. inaequalis such as virulence factors, aggressiveness and mating type. The linkage map presented here represents a significant improvement over currently published maps for studying genome structure and organisation, and for mapping genes of economic importance on the V. inaequalis genome.

High performance photon-pair source based on a fiber-coupled periodically poled KTiOPO4 waveguide.

We demonstrate efficient generation of photon pairs at 1316 nm in a fiber-coupled type-II phase-matched Rb-indiffused waveguide in periodically poled KTiOPO(4). The integrated waveguide source has a pair production rate of 2 x 10(7)/s/mW in a 1.08-nm bandwidth, in good agreement with a theoretical model that takes into account the transversal momentum imparted on the phase matching function by the waveguide. We achieve a Hong-Ou-Mandel quantum-interference visibility of 98.2% after subtraction of accidental coincidences, representing the highest reported value for a waveguide-based photon-pair source.

Broadband amplitude squeezing in a periodically poled KTiOPO4 waveguide.

We generated -2.2 dB of broadband amplitude squeezing at 1064 nm in a periodically poled KTiOPO4 (PPKTP) waveguide by coupling of the fundamental and second-harmonic cw fields. This is the largest amount of squeezing obtained to date in a KTP waveguide, limited by propagation losses. This result paves the way for further improvements by use of lower-loss buried ion-exchanged waveguides.

The incidence and prevalence of diabetes in patients with serious mental illness in North West Wales: two cohorts, 1875-1924 & 1994-2006 compared.

BACKGROUND: Against a background of interest in rates of diabetes in schizophrenia and related psychoses and claims that data from historical periods demonstrate a link that antedates modern antipsychotics, we sought to establish the rate of diabetes in first onset psychosis and subsequent prevalence in historical and contemporary cohorts. METHODS: Analysis of two epidemiologically complete databases of individuals admitted for mental illness. 3170 individuals admitted to the North Wales Asylum between 1875-1924 and tracked over 18,486 patient years and 394 North West Wales first admissions for schizophrenia and related psychoses between 1994 and 2006 and tracked after treatment. RESULTS: The prevalence of Type 2 diabetes among patients with psychoses at time of first admission in both historical and contemporary samples was 0%. The incidence of diabetes remained 0% in the historical sample throughout 15 years of follow-up but rose in the contemporary sample after 3, 5 and 6 years of treatment with an incidence rate double the expected population rate so that the 15 year prevalence is likely to be over 8%. CONCLUSION: No association was found between diabetes and serious mental illness, but there may be an association between diabetes and treatment.

Generation of 250 mW narrowband pulsed ultraviolet light by frequency quadrupling of an amplified erbium-doped fiber laser.

We demonstrate a high-power, narrowband pulsed source at 390 nm by two stages of frequency doubling in periodically poled MgO:LiNbO(3) and periodically poled KTiOPO(4) of an amplified, passively mode-locked fiber laser. With a frequency quadrupling efficiency of 5.5% and a 0.1 nm bandwidth, the 250 mW ultraviolet source is a suitable compact pump source for many entanglement-based quantum information processing tasks.

Otitis media in children (acute).

INTRODUCTION: In the UK, about 30% of children under 3 years of age visit their GPs each year with acute otitis media (AOM), and 97% of these receive antibiotics. In the USA, AOM is the most common reason for outpatient antibiotic treatment. Without antibiotics, AOM resolves within 24 hours in about 60% of children, and within 3 days in about 80% of children. METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of treatments for AOM in children; and what are the effects of interventions to prevent recurrence? We searched: Medline, Embase, The Cochrane Library and other important databases up to January 2007. (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). RESULTS: We found 19 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: analgesics, antibiotics, delayed antibiotics, immediate antibiotics, long-term antibiotic prophylaxis, longer courses of antibiotics, myringotomy, pneumococcal vaccination, tympanostomy with ventilation tubes.