The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

The risk of sudden cardiac death (SCD) is doubled when a patient with chronic kidney disease (CKD) stage 5 starts haemodialysis. Low heart rate variability (HRV) has been reported to be independently associated with increased risk of SCD and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA; 20:5n-3, EPA and 22:6n-3, DHA) may exert anti-arrhythmic effects on cardiac myocytes. Haemodialysis patients have lower serum LC n-3 PUFA levels compared to populations without CKD. Few studies have investigated the relationship between LC n-3 PUFA and HRV in patients with CKD. This study aimed to characterise the variability of LC n-3 PUFA status in patients who recently commenced haemodialysis, and to investigate relationships between LC n-3 PUFA status and HRV. A cross-sectional study was conducted in adults aged 40–80 years with CKD commencing haemodialysis (within 6–10 weeks) (NRES research ethics committee ref: 14/LO/0186). At 2 separate study days, pre-dialysis blood samples were taken to measure fatty acid composition by GC, and HRV monitors (Actiheart, CamNtech Ltd, UK) were fitted after dialysis had started to monitor parameters of cardiac autonomic function during dialysis, during the night, and for a total of 24 h. Forty-five patients (mean age 58 y, SD 9, 20 females/25 males) completed data collection at least once; 91% presented hypertension and 39% had type 2 diabetes. Sample mean omega-3 index (O3I; EPA + DHA as a % of fatty acids in erythrocyte membranes) was very low (3.45%, SD 1.25; median 3.26 %, IQR 1.32); only 2 individuals had O3I > 5%. Variability in erythrocyte EPA (median 0.66 %, IQR 0.42) and DHA (median 2.40 %, IQR 1.32) was limited. Most HRV parameters did not significantly correlate with O3I following adjustment (e.g. age, BMI, β-blockers). Plasma EPA significantly positively correlated with overall and longer phase components of HRV and significantly negatively correlated with beat-to-beat variability over 24 h after full adjustment for confounders. This suggests that although higher circulating EPA concentrations were associated with better cardiac responsivity to environmental stimulations over 24 h, they were also associated with poorer parasympathetic tone (the predominant influence on beat-to-beat HRV). No correlations were observed between plasma DHA and HRV. The divergent pattern of relationships between plasma EPA versus DHA and HRV raises the theory that patients commencing haemodialysis may have compromised conversion of EPA to DHA which may impair vagally-mediated regulation of cardiac autonomic function, a potential mechanism for high risk of SCD.

Interesterified (IE) fats are widely used to replace partially-hydrogenated fats as hard fats with functional and sensory properties needed for spreads/margarines, baked goods, and confectionary, while avoiding the health hazards of trans fats. Detailed mechanistic work to determine the metabolic effects of interesterification of commonly-consumed hard fats has not yet been done. Earlier studies using fats less commonly consumed have shown either neutral or a lowering effect on postprandial lipaemia. We investigated postprandial lipaemia, lipoprotein remodelling, and triacylglycerol-rich lipoprotein (TRL) fraction apolipoprotein concentrations following a common IE blend of palm oil/kernel fractions versus its non-IE counterpart, alongside a reference monounsaturated (MUFA) oil. A 3-armed, double blind, randomized controlled trial (clinicaltrials.gov NCT03191513) in healthy adults (n = 20; 10 men, 10 women) aged 45–75 y, assessed effects of single meals (897 kcal, 50 g fat, 16 g protein, 88 g carbohydrate) on postprandial plasma triacylglycerol (TAG) concentrations, lipoprotein profiles, and TRL fraction apolipoprotein B48 and TAG concentrations. Test fats were IE 80:20 palm stearin/palm kernel fat, the equivalent non-IE fat, and a high-MUFA reference oil (rapeseed oil, RO). Blood was collected at baseline and hourly for 8 h. Linear mixed modelling was performed, adjusting for treatment order and baseline values (ver. 24.0; SPSS Inc., Chicago, IL, USA). Total 8 h incremental area under the curves (iAUC) for plasma TAG concentrations were lower following IE and non-IE compared with RO (mean difference in iAUC: non-IE vs. RO -1.8 mmol/L.h (95% CI -3.3, -0.2); IE vs. RO -2.6 mmol/L.h (95% CI -5.3, 0.0)), but iAUCs for IE and non-IE were not significantly different. There were no differences between IE and non-IE for chylomicron fraction apoB48 concentrations nor TAG:apoB48 ratio. No differences were observed between IE and non-IE for lipoprotein (VLDL, HDL, LDL) particle size or sub-class particle concentrations. However, LDL particle diameters were reduced at 5 and 6 h following IE vs RO (P < 0.05). XXL- (including chylomicron remnants and VLDL particles), XL- and L-VLDL particle concentrations (average diameters > 75, 64, and 53.6 nm respectively) were higher following IE and non-IE vs. RO at 6 h (P < 0.05) and 8 h postprandially (P < 0.005–0.05). In conclusion, both IE and non-IE palmitic acid-rich fats generated a greater preponderance of pro-atherogenic large TRL remnant particles in the late postprandial phase relative to an oleic acid-rich oil. However, the process of interesterification did not modify postprandial TAG response or lipoprotein metabolism.

In the context of an austere financial climate, local health care budget holders are increasingly expected to make and enact decisions to decommission (reduce or stop providing) services. However, little is currently known about the experiences of those seeking to decommission. This paper presents the first national study of decommissioning in the English National Health Service drawing on multiple methods, including: an interview-based review of the contemporary policy landscape of health care decommissioning; a national online survey of commissioners of health care services responsible for managing and enacting budget allocation decisions locally; and illustrative vignettes provided by those who have led decommissioning activities. Findings are presented and discussed in relation to four themes: national-local relationships; organisational capacity and resources for decommissioning; the extent and nature of decommissioning; and intended outcomes of decommissioning. Whilst it is unlikely that local commissioners will be able to ‘successfully’ implement decommissioning decisions unless aspects of engagement, local context and outcomes are addressed, it remains unclear what ‘success’ looks like in terms of a decommissioning process.

We describe the design and performance of the Engineering Development Array, which is a low-frequency radio telescope comprising 256 dual-polarisation dipole antennas working as a phased array. The Engineering Development Array was conceived of, developed, and deployed in just 18 months via re-use of Square Kilometre Array precursor technology and expertise, specifically from the Murchison Widefield Array radio telescope. Using drift scans and a model for the sky brightness temperature at low frequencies, we have derived the Engineering Development Array’s receiver temperature as a function of frequency. The Engineering Development Array is shown to be sky-noise limited over most of the frequency range measured between 60 and 240 MHz. By using the Engineering Development Array in interferometric mode with the Murchison Widefield Array, we used calibrated visibilities to measure the absolute sensitivity of the array. The measured array sensitivity matches very well with a model based on the array layout and measured receiver temperature. The results demonstrate the practicality and feasibility of using Murchison Widefield Array-style precursor technology for Square Kilometre Array-scale stations. The modular architecture of the Engineering Development Array allows upgrades to the array to be rolled out in a staged approach. Future improvements to the Engineering Development Array include replacing the second stage beamformer with a fully digital system, and to transition to using RF-over-fibre for the signal output from first stage beamformers.

Low heart rate variability (HRV) predicts sudden cardiac death. Long-chain (LC) n-3 PUFA (C20–C22) status is positively associated with HRV. This cross-sectional study investigated whether vegans aged 40–70 years (n 23), whose diets are naturally free from EPA (20 : 5n-3) and DHA (22 : 6n-3), have lower HRV compared with omnivores (n 24). Proportions of LC n-3 PUFA in erythrocyte membranes, plasma fatty acids and concentrations of plasma LC n-3 PUFA-derived lipid mediators were significantly lower in vegans. Day-time interbeat intervals (IBI), adjusted for physical activity, age, BMI and sex, were significantly shorter in vegans compared with omnivores (mean difference −67 ms; 95 % CI −130, −3·4, P<0·05), but there were no significant differences over 24 h or during sleep. Vegans had higher overall HRV, measured as 24 h standard deviation of normal-to-normal intervals (SDNN) (mean adjusted difference 27 ms; 95 % CI 1, 52, P=0·039). Conversely, vegans presented with decreased 8 h day-time HRV: mean adjusted difference in SDNN −20 ms; 95 % CI −37, −3, P=0·021, with no differences during nocturnal sleep. Day-time parameters of beat-to-beat HRV (root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals, percentage of adjacent normal-to-normal intervals that differ by >50 % and high-frequency power) were similarly lower in vegans, with no differences during sleep. In conclusion, vegans have higher 24 h SDNN, but lower day-time HRV and shorter day-time IBI relative to comparable omnivores. Vegans may have reduced availability of precursor markers for pro-resolving lipid mediators; it remains to be determined whether there is a direct link with impaired cardiac function in populations with low-n-3 status.

Efficient natural dispersal of herbicide-resistance alleles via seed and pollen can markedly accelerate the incidence of herbicide-resistant weed populations across an agroecoregion. Studies were conducted in western Canada in 2014 and 2015 to investigate pollen- and seed-mediated gene flow in kochia. Pollen-mediated gene flow (PMGF) from glyphosate-resistant (GR) to non-GR kochia was quantified in a field trial (hub and spoke design) at Saskatoon, Saskatchewan. Seed-mediated gene flow of acetolactate synthase (ALS) inhibitor-resistant kochia as a function of tumbleweed speed and distance was estimated in cereal stubble fields at Lethbridge, Alberta and Scott, Saskatchewan. Regression analysis indicated that outcrossing from GR to adjacent non-GR kochia ranged from 5.3 to 7.5%, declining exponentially to 0.1 to 0.4% at 96 m distance. However, PMGF was significantly influenced by prevailing wind direction during pollination (maximum of 11 to 17% outcrossing down-wind). Seed dropped by tumbleweeds varied with distance and plant speed, approaching 90% or more (ca. 100,000 seeds or more) at distances of up to 1,000 m and plant speeds of up to 300 cm s–1. This study highlights the efficient proximal (pollen) and distal (seed) gene movement of this important GR weed.

This article reviews the most likely mechanisms of transmission of the commonly encountered respiratory viruses (influenza, respiratory syncytial virus, parainfluenza, rhinovirus), herpesviruses, and hepatitis viruses, and presents the guidelines used currently for prevention and control that are in use at Strong Memorial Hospital.

In western Canada, more money is spent on wild oat herbicides than on any other weed species, and wild oat resistance to herbicides is the most widespread resistance issue. A direct-seeded field experiment was conducted from 2010 to 2014 at eight Canadian sites to determine crop life cycle, crop species, crop seeding rate, crop usage, and herbicide rate combination effects on wild oat management and canola yield. Combining 2× seeding rates of early-cut barley silage with 2× seeding rates of winter cereals and excluding wild oat herbicides for 3 of 5 yr (2011 to 2013) often led to similar wild oat density, aboveground wild oat biomass, wild oat seed density in the soil, and canola yield as a repeated canola–wheat rotation under a full wild oat herbicide rate regime. Wild oat was similarly well managed after 3 yr of perennial alfalfa without wild oat herbicides. Forgoing wild oat herbicides in only 2 of 5 yr from exclusively summer annual crop rotations resulted in higher wild oat density, biomass, and seed banks. Management systems that effectively combine diverse and optimal cultural practices against weeds, and limit herbicide use, reduce selection pressure for weed resistance to herbicides and prolong the utility of threatened herbicide tools.