Much of our current understanding about novel coronavirus disease 2019 (COVID-19) comes from hospitalised patients. However, the spectrum of mild and subclinical disease has implications for population-level screening and control. Forty-nine participants were recruited from a group of 99 adults repatriated from a cruise ship with a high incidence of COVID-19. Respiratory and rectal swabs were tested by polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sera were tested for anti-SARS-CoV-2 antibodies by enzyme-linked immunosorbent assay (ELISA) and microneutralisation assay. Symptoms, viral shedding and antibody response were examined. Forty-five participants (92%) were considered cases based on either positive PCR or positive ELISA for immunoglobulin G. Forty-two percent of cases were asymptomatic. Only 15% of symptomatic cases reported fever. Serial respiratory and rectal swabs were positive for 10% and 5% of participants respectively about 3 weeks after median symptom onset. Cycle threshold values were high (range 31–45). Attempts to isolate live virus were unsuccessful. The presence of symptoms was not associated with demographics, comorbidities or antibody response. In closed settings, incidence of COVID-19 could be almost double that suggested by symptom-based screening. Serology may be useful in diagnosis of mild disease and in aiding public health investigations.

Turbulent fluxes make a substantial and growing contribution to the energy balance of ice surfaces globally, but are poorly constrained owing to challenges in estimating the aerodynamic roughness length (z0). Here, we used structure from motion (SfM) photogrammetry and terrestrial laser scanning (TLS) surveys to make plot-scale 2-D and 3-D microtopographic estimations of z0 and upscale these to map z0 across an ablating mountain glacier. At plot scales, we found spatial variability in z0 estimates of over two orders of magnitude with unpredictable z0 trajectories, even when classified into ice surface types. TLS-derived surface roughness exhibited strong relationships with plot-scale SfM z0 estimates. At the glacier scale, a consistent increase in z0 of ~0.1 mm d−1 was observed. Space-for-time substitution based on time since surface ice was exposed by snow melt confirmed this gradual increase in z0 over 60 d. These measurements permit us to propose a scale-dependent temporal z0 evolution model where unpredictable variability at the plot scale gives way to more predictable changes of z0 at the glacier scale. This model provides a critical step towards deriving spatially and temporally distributed representations of z0 that are currently lacking in the parameterisation of distributed glacier surface energy balance models.

With generous support from the National Science Foundation, we have spent the past four years developing an archaeological radiocarbon database for the United States. Here, we highlight the importance of spatial data for open-access, national-scale archaeological databases and the development of paleodemography research. We propose a new method for analyzing radiocarbon time series in the context of paleoclimate models. This method forces us to confront one of the central challenges to realizing the full potential of national-scale databases: the quality of the spatial data accompanying radiocarbon dates. We seek to open a national discussion on the use of spatial data in open-source archaeological databases.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) represent a disease continuum with common genetic causes and molecular pathology. We recently identified mutations in the T-cell restricted intracellular antigen-1 (TIA1) protein as a cause of ALS +/− FTD. TIA1 is an RNA-binding protein containing a low complexity domain (LCD) that promotes the assembly of membrane-less organelles, such as stress granules (SG). Whole exome sequencing of two family members with fALS/FTD revealed a novel missense mutation in the TIA1 LCD (P362L). Subsequent screening identified five more TIA1 mutations in six additional ALS patients, but none in controls. All mutation carriers presented with weakness, behavioral abnormalities or language impairments and had a final diagnosis of ALS +/− FTD. Autopsy on five TIA1 mutation carriers showed widespread neurodegeneration with TDP-43 pathology. Round eosinophilic inclusions in lower motor neurons were a consistent feature. Cellular assays revealed abnormal SG dynamics in the presence of TIA1 mutations. In summary, missense mutations in the LCD of TIA1 are a newly recognized cause of ALS/FTD with TDP-43 pathology and strengthen the role of RNA metabolism in the pathogenesis in this disease.

The thickness of supraglacial debris cover controls how it impacts the ablation rate of underlying glacier ice, yet this quantity remains challenging to measure, particularly at glacier scales. We present a relatively straightforward, and cost-effective method to estimate debris thickness exposed above ice cliffs using simplified geometrical measurements from a high-resolution digital surface model (DSM), derived from a terrestrial photographic survey and a Structure from Motion with Multi-View Stereo workflow (SfM-MVS). As the ice surface relief beneath the debris cover is unknown, we assume it to be horizontal and provide error bounds based on characteristic ice-surface slope at the visible debris/ice interface. Debris thickness around the three sampled ice cliffs was highly variable (interquartile range of 0.80–2.85 m) and negatively skewed with a mean thickness of 2.08 ± 0.68 m. Manual, and high-frequency radar, determinations of debris thickness in the same area show similar thickness distributions, but statistically different mean debris thickness, due to local heterogeneity. Debris thickness values derived in this study all exceed estimates from satellite surface temperature inversions. Wider application of the method presented here would provide useful data for improving debris thickness approximations from satellite imagery.

A marginal ice-contact lake at Miage glacier, Mont Blanc, Italian Alps, has been studied to reconstruct changes in lake area. Historical sources, comprising sketches, maps, photographs and scientific surveys, have been supplemented by recent field surveys. These include surveys of glacier surface velocity (which varied along the glacier tongue from 70 ma–1 in the upper part to about 6 ma–1 close to the snout, consistent with data in the literature, showing that velocity rates have remained constant during the last 40 years), volumetric ice-cliff loss (–92 000±180m3 in 2002–03), lake temperature and bathymetry, and qualitative observation of calving events, crevassing, and meltwater production. Results indicate that the lake has been stable for the last half-century following a period of enlargement due to ice-marginal retreat. The lake hydrology is complex, with possible reversals of englacial water flow causing infrequent emptying episodes. The debris cover on the glacier and ice-cliff surfaces seems to have played an important role in the ice-cliff evolution and the calving phenomena; calving is driven by undercutting at the water-line aided by the opening of water- and debris-filled crevasses in the glacier surface.

In this paper the subject is considered from an aerodynamic point of view and no discussion of the possibilities of structural integration of the engine and airframe in the sense of using parts of the engine to contribute to the structural strength or stiffness of the airframe is included, beyond the statement that the simplest consideration and roughest calculations suggest that the sort of deflections obtained on typical aircraft structures at full load do not seem compatible with the integration into such a structure of engines having rotating parts and fine clearances, although in the case of units such as ram-jets such structural integration may well be practicable and desirable. Another structural problem which leads naturally to the consideration of engine and airframe as a single unit is the problem of improving flutter characteristics by placing the concentrated masses of the engines in suitable positions relative to the wing.

To write a paper on the work of the Royal Aircraft Establishment is a formidable task. To summarise the programme of work of the Establishment would either provide material for a series of lectures or, if compressed to a single lecture, would lead to a cursory and superficial treatment. I make no apologies, therefore, for not attempting any sort of complete survey. Within the scope of this lecture all I intend to do is to give a brief description of the RAE, what it is, what it does and how it is organised and then to consider a few items drawn from three of the RAE's research programmes, which have been selected to show some of the characteristics of the RAE and the kind of work which goes on there.

The first series of items to be presented fall in the field of the slender wing. The great potentiality of the slender wing for a wide range of applications was apparent from the time the concept was first considered. What I want to stress is the enormous range of detailed researches which are required before such a concept can be used in practical designs.

Since this is a Tizard Memorial Lecture, I think it is appropriate that I should tell you something about Operational Research in the Royal Air Force as it is carried on today. The RAF has a great tradition of actively using operational research to promote the efficiency of the Service and it was Sir Henry Tizard who initiated this tradition and sustained it until it was well established. Indeed, he was responsible for the much wider application of science to air warfare, but I am not attempting to cover the wider field in this lecture.

Background: Altered mesenteric perfusion may be a contributor to the development of necrotising enterocolitis in patients with hypoplastic left heart syndrome. The goal of this study was to document mesenteric flow patterns in patients with hypoplastic left heart syndrome pre- and post-hybrid procedure. Methods: A prospective study on all patients with hypoplatic left heart syndrome undergoing the hybrid procedure was conducted. Doppler ultrasound analysis of the coeliac and superior mesenteric artery was performed. Results: A total of 13 patients were evaluated. There was a significant difference in the coeliac artery effective velocity-time intergral pre- and post-hybrid procedure (8.69±3.84 versus 12.51±4.95 cm, respectively). There were significant differences in the superior mesenteric artery antegrade velocity-time integral pre- and post-hybrid procedure (6.86±2.45 versus 10.52±2.64 cm, respectively) and superior mesenteric artery effective velocity-time integral pre- and post-hybrid procedure (6.22±2.68 versus 9.73±2.73 cm, respectively). There were no significant differences between the coeliac and superior mesenteric artery Doppler indices in the pre-hybrid procedure; there were, however, significant differences in the post-hybrid procedure between coeliac and superior mesenteric artery antegrade velocity-time integral (13.8 2±5.60 versus 10.52±2.64 cm, respectively) and effective velocity-time integral (13.04±4.71 versus 9.73±2.73 cm, respectively). Conclusion: Doppler mesenteric indices of perfusion improve in patients with hypoplastic left heart syndrome after the hybrid procedure; however, there appears to be preferential flow to the coeliac artery versus the superior mesenteric artery in these patients post-procedure.

Data were extracted from the case records of UK patients admitted with laboratory-confirmed influenza A(H1N1)pdm09. White and non-White patients were characterized by age, sex, socioeconomic status, pandemic wave and indicators of pre-morbid health status. Logistic regression examined differences by ethnicity in patient characteristics, care pathway and clinical outcomes; multivariable models controlled for potential confounders. Whites (n = 630) and non-Whites (n = 510) differed by age, socioeconomic status, pandemic wave of admission, pregnancy, recorded obesity, previous and current smoking, and presence of chronic obstructive pulmonary disease. After adjustment for a priori confounders non-Whites were less likely to have received pre-admission antibiotics [adjusted odds ratio (aOR) 0·43, 95% confidence interval (CI) 0·28–0·68, P < 0·001) but more likely to receive antiviral drugs as in-patients (aOR 1·53, 95% CI 1·08–2·18, P = 0·018). However, there were no significant differences by ethnicity in delayed admission, severity at presentation for admission, or likelihood of severe outcome.

Understanding the nutritional demands on serving military personnel is critical to inform training schedules and dietary provision. Troops deployed to Afghanistan face austere living and working environments. Observations from the military and those reported in the British and US media indicated possible physical degradation of personnel deployed to Afghanistan. Therefore, the present study aimed to investigate the changes in body composition and nutritional status of military personnel deployed to Afghanistan and how these were related to physical fitness. In a cohort of British Royal Marines (n 249) deployed to Afghanistan for 6 months, body size and body composition were estimated from body mass, height, girth and skinfold measurements. Energy intake (EI) was estimated from food diaries and energy expenditure measured using the doubly labelled water method in a representative subgroup. Strength and aerobic fitness were assessed. The mean body mass of volunteers decreased over the first half of the deployment ( − 4·6 (sd 3·7) %), predominately reflecting fat loss. Body mass partially recovered (mean +2·2 (sd 2·9) %) between the mid- and post-deployment periods (P< 0·05). Daily EI (mean 10 590 (sd 3339) kJ) was significantly lower than the estimated daily energy expenditure (mean 15 167 (sd 1883) kJ) measured in a subgroup of volunteers. However, despite the body mass loss, aerobic fitness and strength were well maintained. Nutritional provision for British military personnel in Afghanistan appeared sufficient to maintain physical capability and micronutrient status, but providing appropriate nutrition in harsh operational environments must remain a priority.