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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.
The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with
15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination
made over a 288-MHz band centred at 887.5 MHz.
The ‘sick-quitter’ hypothesis states that mental disorders associated with alcohol abstinence are accounted for by people who stop consuming alcohol because of poor health.
We investigated the association between alcohol abstinence and symptoms of common mental disorder and personality disorder, distinguishing between lifelong abstinence and abstinence following previous consumption.
Analyses were based on the British National Survey of Psychiatric Morbidity 2000, which sampled 8580 residents aged 16 to 74 years. Heavy consumers of alcohol were excluded, using the Alcohol Use Disorders Identification Test Questionnaire. Symptoms of common mental disorder (depression/anxiety) were identified by the Clinical Interview Schedule. The screening questionnaire of the Structured Clinical Interview for Axis II Personality Disorders was used to identify potential personality disorder. Self-reported alcohol abstinence was divided into lifelong abstinence and previous consumption. Previous consumers were asked why they had stopped. Covariates included socioeconomic status, social activity and general health status.
After adjustment, alcohol abstinence was associated with both common mental disorder symptoms and any personality disorder, but only for previous consumers (respective odds ratios 1.70 (1.23-2.34) and 1.45 (1.09-1.94)). Associations were non-specific, being apparent for most individual mental disorder symptoms and personality disorder categories. More detailed analysis indicated that associations were limited to previous consumers who reported ceasing alcohol consumption for health reasons.
The results were consistent with the ‘sick-quitter’ hypothesis and should be taken into account when interpreting associations between moderate alcohol consumption and beneficial health outcomes.
Autism Spectrum Disorders (ASDs) affect 1% of children and are associated with lifelong psychosocial impairments. The majority of children with ASD will experience co-occurring psychiatric disorders. In the UK, antipsychotics remain unlicensed for use in ASDs, however 10% of children with ASD receive antipsychotic treatment; the co-occurring disorders being targeted by these medications remains unclear.
To examine rates of antipsychotic medication use and identify associated co-occurring disorders among children with ASD receiving psychiatric care.
The sample consisted of 2844 children aged 2 to 17 with a NHS clinician recorded ICD-10 diagnoses for ASD between 2008–2013. Clinical variables extracted from their anonymised electronic patient records included disorder severity, medication use, co-occurring ICD-10 diagnoses, family characteristics, demographics and antipsychotic use.
Of the 2844 children (79% male), the majority (57%) had co-occurring psychiatric diagnoses. 313 (11%) received antipsychotic medication. The proportion of children aged 13 to 17 years and 6 to 12 years prescribed antipsychotics was 19% and 7% respectively. After controlling for socio-demographic factors, disorder severity, specialist treatment, inpatient duration, risk of self harm, violence to others, self injurious behaviour, maltreatment history, parental mental illness, caregiver anxiety, and neighbourhood deprivation, multivariate regression analysis revealed only hyperactivity disorders (O.R 1.94, 95%C.I. 1.32–2.86), psychotic disorders (O.R 5.12 95% C.I. 2.6–10.1), mood disorders (O.R 2.02, 95%C.I. 1.04–3.92) and intellectual disability (O.R 2.89 95% C.I. 1.89–4.71) were associated with anti-psychotic use.
The prescription of antipsychotic medications in this UK ASD clinical sample is strongly associated with specific co-occurring psychiatric disorders and intellectual disability.
Mood instability is an important problem but has received relatively little research attention. Natural language processing (NLP) is a novel method, which can used to automatically extract clinical data from electronic health records (EHRs).
To extract mood instability data from EHRs and investigate its impact on people with mental health disorders.
Data on mood instability were extracted using NLP from 27,704 adults receiving care from the South London and Maudsley NHS Foundation Trust (SLaM) for affective, personality or psychotic disorders. These data were used to investigate the association of mood instability with different mental disorders and with hospitalisation and treatment outcomes.
Mood instability was documented in 12.1% of people included in the study. It was most frequently documented in people with bipolar disorder (22.6%), but was also common in personality disorder (17.8%) and schizophrenia (15.5%). It was associated with a greater number of days spent in hospital (B coefficient 18.5, 95% CI 12.1–24.8), greater frequency of hospitalisation (incidence rate ratio 1.95, 1.75–2.17), and an increased likelihood of prescription of antipsychotics (2.03, 1.75–2.35).
Using NLP, it was possible to identify mood instability in a large number of people, which would otherwise not have been possible by manually reading clinical records. Mood instability occurs in a wide range of mental disorders. It is generally associated with poor clinical outcomes. These findings suggest that clinicians should screen for mood instability across all common mental health disorders. The data also highlight the utility of NLP for clinical research.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Dietary Zn has significant impacts on the growth and development of breeding rams. The objectives of this study were to evaluate the effects of dietary Zn source and concentration on serum Zn concentration, growth performance, wool traits and reproductive performance in rams. Forty-four Targhee rams (14 months; 68 ± 18 kg BW) were used in an 84-day completely randomized design and were fed one of three pelleted dietary treatments: (1) a control without fortified Zn (CON; n = 15; ~1 × NRC); (2) a diet fortified with a Zn amino acid complex (ZnAA; n = 14; ~2 × NRC) and (3) a diet fortified with ZnSO4 (ZnSO4; n = 15; ~2 × NRC). Growth and wool characteristics measured throughout the course of the study were BW, average daily gain (ADG), dry matter intake (DMI), feed efficiency (G : F), longissimus dorsi muscle depth (LMD), back fat (BF), wool staple length (SL) and average fibre diameter (AFD). Blood was collected from each ram at four time periods to quantify serum Zn and testosterone concentrations. Semen was collected 1 to 2 days after the trial was completed. There were no differences in BW (P = 0.45), DMI (P = 0.18), LMD (P = 0.48), BF (P = 0.47) and AFD (P = 0.9) among treatment groups. ZnSO4 had greater (P ≤ 0.03) serum Zn concentrations compared with ZnAA and CON treatments. Rams consuming ZnAA had greater (P ≤ 0.03) ADG than ZnSO4 and CON. There tended to be differences among groups for G : F (P = 0.06), with ZnAA being numerically greater than ZnSO4 and CON. Wool staple length regrowth was greater (P < 0.001) in ZnSO4 and tended to be longer (P = 0.06) in ZnAA treatment group compared with CON. No differences were observed among treatments in scrotal circumference, testosterone, spermatozoa concentration within ram semen, % motility, % live sperm and % sperm abnormalities (P ≥ 0.23). Results indicated beneficial effects of feeding increased Zn concentrations to developing Targhee rams, although Zn source elicited differential responses in performance characteristics measured.
A theoretically based relationship for the Darcy–Weisbach friction factor
for rough-bed open-channel flows is derived and discussed. The derivation procedure is based on the double averaging (in time and space) of the Navier–Stokes equation followed by repeated integration across the flow. The obtained relationship explicitly shows that the friction factor can be split into at least five additive components, due to: (i) viscous stress; (ii) turbulent stress; (iii) dispersive stress (which in turn can be subdivided into two parts, due to bed roughness and secondary currents); (iv) flow unsteadiness and non-uniformity; and (v) spatial heterogeneity of fluid stresses in a bed-parallel plane. These constitutive components account for the roughness geometry effect and highlight the significance of the turbulent and dispersive stresses in the near-bed region where their values are largest. To explore the potential of the proposed relationship, an extensive data set has been assembled by employing specially designed large-eddy simulations and laboratory experiments for a wide range of Reynolds numbers. Flows over self-affine rough boundaries, which are representative of natural and man-made surfaces, are considered. The data analysis focuses on the effects of roughness geometry (i.e. spectral slope in the bed elevation spectra), relative submergence of roughness elements and flow and roughness Reynolds numbers, all of which are found to be substantial. It is revealed that at sufficiently high Reynolds numbers the roughness-induced and secondary-currents-induced dispersive stresses may play significant roles in generating bed friction, complementing the dominant turbulent stress contribution.
Gut cell losses contribute to overall feed efficiency due to the energy requirement for cell replenishment. Intestinal epithelial cells are sloughed into the intestinal lumen as digesta passes through the gastrointestinal tract, where cells are degraded by endonucleases. This leads to fragmented DNA being present in faeces, which may be an indicator of gut cell loss. Therefore, measuring host faecal DNA content could have potential as a non-invasive marker of gut cell loss and result in a novel technique for the assessment of how different feed ingredients impact upon gut health. Faecal calprotectin (CALP) is a marker of intestinal inflammation. This was a pilot study designed to test a methodology for extracting and quantifying DNA from pig faeces, and to assess whether any differences in host faecal DNA and CALP could be detected. An additional aim was to determine whether any differences in the above measures were related to the pig performance response to dietary yeast-enriched protein concentrate (YPC). Newly weaned (∼26.5 days of age) Large White × Landrace × Pietrain piglets (8.37 kg ±1.10, n = 180) were assigned to one of four treatment groups (nine replicates of five pigs), differing in dietary YPC content: 0% (control), 2.5%, 5% and 7.5% (w/w). Pooled faecal samples were collected on days 14 and 28 of the 36-day trial. Deoxyribonucleic acid was extracted and quantitative PCR was used to assess DNA composition. Pig genomic DNA was detected using primers specific for the pig cytochrome b (CYTB) gene, and bacterial DNA was detected using universal 16S primers. A pig CALP ELISA was used to assess gut inflammation. Dietary YPC significantly reduced feed conversion ratio (FCR) from weaning to day 14 (P<0.001), but not from day 14 to day 28 (P = 0.220). Pig faecal CYTB DNA content was significantly (P = 0.008) reduced in YPC-treated pigs, with no effect of time, whereas total faecal bacterial DNA content was unaffected by diet or time (P>0.05). Faecal CALP levels were significantly higher at day 14 compared with day 28, but there was no effect of YPC inclusion and no relationship with FCR. In conclusion, YPC reduced faecal CYTB DNA content and this correlated positively with FCR, but was unrelated to gut inflammation, suggesting that it could be a non-invasive marker of gut cell loss. However, further validation experiments by an independent method are required to verify the origin of pig faecal CYTB DNA as being from sloughed intestinal epithelial cells.
The Parkes 64 m telescope has been used to survey a complete sample of nearby red giants (i.e. not members of close binaries or showing strong emission lines of CaII). The sample consisted of all 82 stars in the Bright Star Catalogue within 30 pc having spectral types G, K, M and luminosity classes I, II, III south of the celestial equator.
In this paper we discuss 80 MHz heliograph observations of the multiple source structure and polarization of a type IV solar radio outburst on 1970 November 16. At times during the event six sources were present. Three of these were highly circularly polarized in a L.H. sense and two in a R.H. sense. The sixth source was extended and had oppositely polarized edges. From the source behaviour we conclude that the radio emission came from two expanding and one stationary magnetic arch.
Young supernova remnants are poorly understood and few are known. Further examples may be present, but unrecognised, within existing catalogues of radio sources. G274.68–2.84 was recently suggested as one such candidate but our new radio map from the Australia Telescope indicates that it is not a supernova remnant. Rather, it appears to be extragalactic with a strong, variable, flat-spectrum nucleus, and a bright X-ray counterpart.
A unique data set of 160 MHz solar noise storm positions and polarizations covering a complete sunspot cycle interval from the Skylab period of 1973 through the Solar Maximum intervals of 1980 and 1984 is presented in the form of 27.28-day synoptic plots.
The magnetic structure in the source region of a type II burst and along the path of the type II disturbance has remained an enigma despite over 20 years of radio observations of the Sun (see e.g. reviews by Wild and Smerd (1972) and McLean (1974)). This paper describes the first radioheliograph observations of a type II burst near coronal magnetic structures depicted by soft X-ray pictures. It will be shown that three separate lanes in a type II burst are associated with three separate source regions each located almost radially above a soft X-ray loop. To explain these observations a model is derived in which a wide-fronted m.h.d. disturbance travels from the flare explosion along magnetic field lines and then intersects successively with three coronal streamer structures each located above a soft X-ray loop. An estimate of the magnetic flux density along the soft X-ray loops is obtained from the velocity of the m.h.d. disturbance.
We present a catalogue of 668 major metre-wavelength radio events. The data was collected from dynamic spectra (taken at Dapto, N.S.W. until 1966 and at Culgoora, N.S.W. thereafter) by means of a radio spectrograph, which records the intensity of radio emission as a function of both frequency and time. A description of the major types of metre-wavelength phenomena can be found in Wild et al. (1963), Kundu (1965), Wild and Smerd (1972) and Kruger (1979), and details of the radio spectrograph in Sheridan (1963, 1967) and Labrum (1972).
Travelling disturbances in the solar corona with velocities ~103 km/s manifest themselves at radio frequencies by two distinctive phenomena—the type II burst, the spectrum of which shows a slow frequency drift that corresponds to quasi-radial outward motion, and the moving type IV burst, for which positional observations show transverse motion directly. A close relation between the two phenomena has long been suspected, and each type has separately been ascribed to a shock wave disturbance. In this paper we summarize three events recorded by the Culgoora radioheliograph and spectograph (two in the course of publication and one unpublished) in each of which a type II and a moving type IV burst can be consistently attributed to the effects of a common shock wave.
In a previous paper of this issue (Stewart and Nelson 1979 — Paper A) we showed that for extended bursts a good correlation exists between the observed 100 keV X-ray slux density and the 3.75 or 9.4 GHz microwave flux density. We also showed that the microwave spectrum of these bursts was much flatter (S ∝ f1.0 on the average) than the optically thick (self-absorbed) spectrum observed for impulsive microwave bursts (Crannell et al. 1978; Dulk et al. 1978). Furthermore, the microwave turnover frequency was > 10 GHz in eight of the nine events studied and <20 GHz in four of these cases. The remaining event, which was severely occulted by the solar limb, had a turnover frequency of ∽ 1 GHz.
We describe bright microwave events that were first detected with the Parkes 64-m telescope at 8.4 or 22 GHz from six active-chromosphere stars. In some flares spectral data were obtained over a large frequency range from simultaneous measurements with the Parkes reflector (8.4 or 22 GHz), the Tidbinbilla interferometer (8.4 and 2.29 GHz), the Fleurs synthesis telescope (1.42 GHz) and the Molonglo Observatory synthesis telescope (0.843 GHz). Data on circular polarization were obtained from the Parkes observations at 8.4 GHz.
The stars were in a wide variety of evolutionary states, ranging from a single pre-main-sequence star (HD 36705), two RS CVn binaries (HD 127535, HD 128171), an Algol (HD 132742) and two apparently single K giants (HD 32918 and HD 196818). Their high brightness temperatures, positive spectral indices and low polarization are consistent with optically thick gyrosynchrotron emission from mildly relativistic electrons with average energies 0.5 to 3 MeV gyrating in inhomogeneous magnetic fields of 5 to 100 G.
It has generally been accepted that moving type IV bursts are generated as synchrotron radiation from energetic electrons high in the solar corona (Boischot and Denisse 1957). At 80 MHz the peak brightness temperature is usually ~ 108 K and the radiation becomes highly circularly polarized as the burst decays. This has led several authors (Kai 1969; Dulk 1970, 1973; Schmahl 1972; Robinson 1974, 1977; Nelson 1977) to the conclusion that the radiation comes from mildly relativistic (~ 100 keV) electrons and occurs at low harmonics of the gyro-frequency (gyro-synchrotron radiation). We present evidence of moving type IV bursts at 43, 80 and 160 MHz with brightness temperatures of ~ 109 K, and one at 43 MHz as high as 1010 K. The number (~ 1033) of energetic (≥ 1 MeV) electrons which is required in order to explain such high brightness temperatures by incoherent gyro-synchrotron emission is very large and near the upper limit for the number of fast electrons accelerated in the second phase of a solar flare. If amplification takes place a smaller number of electrons with energies ~ 100 keV would be required.