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It is important to understand the temporal trend of the paediatric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load to estimate the transmission potential of children in schools and communities. We determined the differences in SARS-CoV-2 viral load dynamics between nasopharyngeal samples of infected asymptomatic and symptomatic children. Serial cycle threshold values of SARS-CoV-2 from the nasopharynx of a cohort of infected children were collected for analysis. Among 17 infected children, 10 (58.8%) were symptomatic. Symptomatic children, when compared to asymptomatic children, had higher viral loads (mean cycle threshold on day 7 of illness 28.6 vs. 36.7, P = 0.02). Peak SARS-CoV-2 viral loads occurred around day 2 of illness in infected children. Although we were unable to directly demonstrate infectivity, the detection of significant amount of virus in the upper airway of asymptomatic children suggest that they have the potential to shed and transmit SARS-CoV-2. Our study highlights the importance of contact tracing and screening for SARS-CoV-2 in children with epidemiological risk factors regardless of their symptom status, in order to improve containment of the virus in the community, including educational settings.
An acute gastroenteritis (AGE) outbreak caused by a norovirus occurred at a hospital in Shanghai, China, was studied for molecular epidemiology, host susceptibility and serological roles. Rectal and environmental swabs, paired serum samples and saliva specimens were collected. Pathogens were detected by real-time polymerase chain reaction and DNA sequencing. Histo-blood group antigens (HBGA) phenotypes of saliva samples and their binding to norovirus protruding proteins were determined by enzyme-linked immunosorbent assay. The HBGA-binding interfaces and the surrounding region were analysed by the MegAlign program of DNAstar 7.1. Twenty-seven individuals in two care units were attacked with AGE at attack rates of 9.02 and 11.68%. Eighteen (78.2%) symptomatic and five (38.4%) asymptomatic individuals were GII.6/b norovirus positive. Saliva-based HBGA phenotyping showed that all symptomatic and asymptomatic cases belonged to A, B, AB or O secretors. Only four (16.7%) out of the 24 tested serum samples showed low blockade activity against HBGA-norovirus binding at the acute phase, whereas 11 (45.8%) samples at the convalescence stage showed seroconversion of such blockade. Specific blockade antibody in the population played an essential role in this norovirus epidemic. A wide HBGA-binding spectrum of GII.6 supports a need for continuous health attention and surveillance in different settings.
In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.
Only a few studies have been performed on seed germination of perennial ephemeral species native to the cold deserts of central Asia. We hypothesized that seeds of the cold desert perennial ephemeral Leontice incerta exhibit versatility in the timing of germination, that is, having the capacity to germinate at any time in summer, autumn and next spring. At dispersal in late May, only about 30% of the seeds could germinate; thus, a high percentage of the seeds was dormant. Seeds had a fully developed embryo, and dry storage, cold stratification, warm stratification and gibberellin promoted germination; we concluded that they have non-deep physiological dormancy. Seeds buried under natural conditions during summer germinated to 57–86% in autumn (late October) when exhumed and incubated at 5/2–25/15°C. However, seeds were sown in soil exposed to natural temperature and (low) precipitation did not germinate until next spring when the soil was moist. Thus, like various cold desert annuals, seeds of the perennial L. incerta can germinate in summer, autumn and next spring, depending on the availability of soil moisture (rainfall). Rainfall in cold deserts can play an important role in shaping seed germination traits of desert plants.
Sub-acute ruminal acidosis (SARA) can reduce the production efficiency and impair the welfare of cattle, potentially in all production systems. The aim of this study was to characterise measurable postmortem observations from divergently managed intensive beef finishing farms with high rates of concentrate feeding. At the time of slaughter, we obtained samples from 19 to 20 animals on each of 6 beef finishing units (119 animals in total) with diverse feeding practices, which had been subjectively classified as being high risk (three farms) or low risk (three farms) for SARA on the basis of the proportions of barley, silage and straw in the ration. We measured the concentrations of histamine, lipopolysaccharide (LPS), lactate and other short-chain fatty acids (SCFAs) in ruminal fluid, LPS and SCFA in caecal fluid. We also took samples of the ventral blind sac of the rumen for histopathology, immunohistopathology and gene expression. Subjective assessments were made of the presence of lesions on the ruminal wall, the colour of the lining of the ruminal wall and the shape of the ruminal papillae. Almost all variables differed significantly and substantially among farms. Very few pathological changes were detected in any of the rumens examined. The animals on the high-risk diets had lower concentrations of SCFA and higher concentrations of lactate and LPS in the ruminal fluid. Higher LPS concentrations were found in the caecum than the rumen but were not related to the risk status of the farm. The diameters of the stratum granulosum, stratum corneum and of the vasculature of the papillae, and the expression of the gene TLR4 in the ruminal epithelium were all increased on the high-risk farms. The expression of IFN-γ and IL-1β and the counts of cluster of differentiation 3 positive and major histocompatibility complex class two positive cells were lower on the high-risk farms. High among-farm variation and the unbalanced design inherent in this type of study in the field prevented confident assignment of variation in the dependent variables to individual dietary components; however, the CP percentage of the total mixed ration DM was the factor that was most consistently associated with the variables of interest. Despite the strong effect of farm on the measured variables, there was wide inter-animal variation.
The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
Item 9 of the Patient Health Questionnaire-9 (PHQ-9) queries about thoughts of death and self-harm, but not suicidality. Although it is sometimes used to assess suicide risk, most positive responses are not associated with suicidality. The PHQ-8, which omits Item 9, is thus increasingly used in research. We assessed equivalency of total score correlations and the diagnostic accuracy to detect major depression of the PHQ-8 and PHQ-9.
We conducted an individual patient data meta-analysis. We fit bivariate random-effects models to assess diagnostic accuracy.
16 742 participants (2097 major depression cases) from 54 studies were included. The correlation between PHQ-8 and PHQ-9 scores was 0.996 (95% confidence interval 0.996 to 0.996). The standard cutoff score of 10 for the PHQ-9 maximized sensitivity + specificity for the PHQ-8 among studies that used a semi-structured diagnostic interview reference standard (N = 27). At cutoff 10, the PHQ-8 was less sensitive by 0.02 (−0.06 to 0.00) and more specific by 0.01 (0.00 to 0.01) among those studies (N = 27), with similar results for studies that used other types of interviews (N = 27). For all 54 primary studies combined, across all cutoffs, the PHQ-8 was less sensitive than the PHQ-9 by 0.00 to 0.05 (0.03 at cutoff 10), and specificity was within 0.01 for all cutoffs (0.00 to 0.01).
PHQ-8 and PHQ-9 total scores were similar. Sensitivity may be minimally reduced with the PHQ-8, but specificity is similar.
Sufficient amino acid (AA) transport is essential to ensure the normal physiological function and growth of growing animals. The processes of AA sensing and transport in humans and murine animals, but rarely in goats, have been arousing great interest recently. This study was conducted to investigate the messenger RNA expression patterns of lysophosphatidic acid receptor 5 (LPAR5), guanine nucleotide-binding protein α-transducing 3 (GNAT3) and important partial AA transporters in digestive tracts, metabolic organs and muscles of growing goats. The results showed that these genes were widely expressed in goats, and had different expression patterns. LPAR5, GNAT3, solute carrier (SLC38A2), SLC7A7, SLC7A1 and SLC3A1 were rarely expressed in the rumen, but were highly expressed in the abomasum and intestine which are the main sites of AA absorption. GNAT3, SLC38A1, SLC38A2, SLC6A19, SLC7A7 and SLC7A1 showed comparatively high expression in the pancreas and the vital digestive glands, and the relatively high expression of these nine genes were noted in the tibialis posterior, the active muscle in energy metabolism. The correlation analysis showed that there were certain positive correlation among most genes. The current results indicate that the AA sensing and transport occur extensively in the abomasum and small intestine, metabolic organs and muscle tissues of ruminants, and that related genes have tissue specificity.
The gastrointestinal tract (GIT) of animals is capable of sensing various kinds of nutrients via G-protein coupled receptor-mediated signaling transduction pathways, and the process is known as ‘gut nutrient chemosensing’. GPR40, GPR41, GPR43 and GPR119 are chemoreceptors for free fatty acids (FFAs) and lipid derivatives, but they are not well studied in small ruminants. The objective of this study is to determine the expression of GPR40, GPR41, GPR43 and GPR119 along the GIT of kid goats under supplemental feeding (S) v. grazing (G) during early development. In total, 44 kid goats (initial weight 1.35±0.12 kg) were slaughtered for sampling (rumen, abomasum, duodenum, jejunum, ileum, cecum, colon and rectum) between days 0 and 70. The expression of GPR41 and GPR43 were measured at both mRNA and protein levels, whereas GPR40 and GPR119 were assayed at protein level only. The effects of age and feeding system on their expression were variable depending upon GIT segments, chemoreceptors and expression level (mRNA or protein), and sometimes feeding system × age interactions (P<0.05) were observed. Supplemental feeding enhanced expression of GPR40, GPR41 and GPR43 in most segments of the GIT of goats, whereas G enhanced expression of GPR119. GPR41 and GPR43 were mainly expressed in rumen, abomasum and cecum, with different responses to age and feeding system. GPR41 and GPR43 expression in abomasum at mRNA level was greatly (P<0.01) affected by both age and feeding system; whereas their expression in rumen and abomasum at protein level were different, feeding system greatly (P<0.05) affected GPR41 expression, but had no effect (P>0.05) on GPR43 expression; and there were no feeding system×age interactions (P>0.05) on GPR41 and GPR43 protein expression. The expression of GPR41 and GPR43 in rumen and abomasum linearly (P<0.01) increased with increasing age (from days 0 to 70). Meanwhile, age was the main factor affecting GPR40 expression throughout the GIT. These outcomes indicate that age and feeding system are the two factors affecting chemoreceptors for FFAs and lipid derivatives expression in the GIT of kids goats, and S enhanced the expression of chemoreceptors for FFAs, whereas G gave rise to greater expression of chemoreceptors for lipid derivatives. Our results suggest that enhanced expression of chemoreceptors for FFAs might be one of the benefits of early supplemental feeding offered to young ruminants during early development.
While studies suggest that nutritional supplementation may reduce aggressive behavior in children, few have examined their effects on specific forms of aggression. This study tests the primary hypothesis that omega-3 (ω-3), both alone and in conjunction with social skills training, will have particular post-treatment efficacy for reducing childhood reactive aggression relative to baseline.
In this randomized, double-blind, stratified, placebo-controlled, factorial trial, a clinical sample of 282 children with externalizing behavior aged 7–16 years was randomized into ω-3 only, social skills only, ω-3 + social skills, and placebo control groups. Treatment duration was 6 months. The primary outcome measure was reactive aggression collected at 0, 3, 6, 9, and 12 months, with antisocial behavior as a secondary outcome.
Children in the ω-3-only group showed a short-term reduction (at 3 and 6 months) in self-report reactive aggression, and also a short-term reduction in overall antisocial behavior. Sensitivity analyses and a robustness check replicated significant interaction effects. Effect sizes (d) were small, ranging from 0.17 to 0.31.
Findings provide some initial support for the efficacy of ω-3 in reducing reactive aggression over and above standard care (medication and parent training), but yield only preliminary and limited support for the efficacy of ω-3 in reducing overall externalizing behavior in children. Future studies could test further whether ω-3 shows promise in reducing more reactive, impulsive forms of aggression.
Different diagnostic interviews are used as reference standards for major depression classification in research. Semi-structured interviews involve clinical judgement, whereas fully structured interviews are completely scripted. The Mini International Neuropsychiatric Interview (MINI), a brief fully structured interview, is also sometimes used. It is not known whether interview method is associated with probability of major depression classification.
To evaluate the association between interview method and odds of major depression classification, controlling for depressive symptom scores and participant characteristics.
Data collected for an individual participant data meta-analysis of Patient Health Questionnaire-9 (PHQ-9) diagnostic accuracy were analysed and binomial generalised linear mixed models were fit.
A total of 17 158 participants (2287 with major depression) from 57 primary studies were analysed. Among fully structured interviews, odds of major depression were higher for the MINI compared with the Composite International Diagnostic Interview (CIDI) (odds ratio (OR) = 2.10; 95% CI = 1.15–3.87). Compared with semi-structured interviews, fully structured interviews (MINI excluded) were non-significantly more likely to classify participants with low-level depressive symptoms (PHQ-9 scores ≤6) as having major depression (OR = 3.13; 95% CI = 0.98–10.00), similarly likely for moderate-level symptoms (PHQ-9 scores 7–15) (OR = 0.96; 95% CI = 0.56–1.66) and significantly less likely for high-level symptoms (PHQ-9 scores ≥16) (OR = 0.50; 95% CI = 0.26–0.97).
The MINI may identify more people as depressed than the CIDI, and semi-structured and fully structured interviews may not be interchangeable methods, but these results should be replicated.
Declaration of interest
Drs Jetté and Patten declare that they received a grant, outside the submitted work, from the Hotchkiss Brain Institute, which was jointly funded by the Institute and Pfizer. Pfizer was the original sponsor of the development of the PHQ-9, which is now in the public domain. Dr Chan is a steering committee member or consultant of Astra Zeneca, Bayer, Lilly, MSD and Pfizer. She has received sponsorships and honorarium for giving lectures and providing consultancy and her affiliated institution has received research grants from these companies. Dr Hegerl declares that within the past 3 years, he was an advisory board member for Lundbeck, Servier and Otsuka Pharma; a consultant for Bayer Pharma; and a speaker for Medice Arzneimittel, Novartis, and Roche Pharma, all outside the submitted work. Dr Inagaki declares that he has received grants from Novartis Pharma, lecture fees from Pfizer, Mochida, Shionogi, Sumitomo Dainippon Pharma, Daiichi-Sankyo, Meiji Seika and Takeda, and royalties from Nippon Hyoron Sha, Nanzando, Seiwa Shoten, Igaku-shoin and Technomics, all outside of the submitted work. Dr Yamada reports personal fees from Meiji Seika Pharma Co., Ltd., MSD K.K., Asahi Kasei Pharma Corporation, Seishin Shobo, Seiwa Shoten Co., Ltd., Igaku-shoin Ltd., Chugai Igakusha and Sentan Igakusha, all outside the submitted work. All other authors declare no competing interests. No funder had any role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
Aphelinus mali (Haldeman) is an effective natural enemy of woolly apple aphid (WAA), Eriosoma lanigerum (Hausmann). Previous studies have found that, with WAA from Shandong Province (Qingdao) as the host, there are significant differences in various biological characteristics between a Shandong clade and Liaoning clade of A. mali. The ability of the Shandong clade to control this aphid was significantly higher than that of the Liaoning clade in Shandong Province. In order to determine whether differences were caused by better adaptation of the Shandong parasitoid clade to the population of the host in that province or if it represents a more general fitness of this clade to control the host regardless of location, we compared the same parasitoid clades with hosts from Hebei Province. We found no significant differences in the developmental threshold temperature, effective accumulated temperature, fecundity, longevity, and oviposition period of the two clades, but the duration of host searching of the Shandong clade was significantly longer than that of the Liaoning clade. The instantaneous attack rate, the control ability (a/Th), the search parameter (Q) of the Shandong clade (0.0946, 0.543, 0.0725) of A. mali were higher than that of the Liaoning clade (0.0713, 0.382, 0.0381), and therefore, with WAA from Hebei Province as the host, the host adaptability of the Shandong clade of A. mali was not worse than that of the Liaoning clade, while the pest control ability of the Shandong clade was still greater than that of the Liaoning clade.
The LOFAR Tied Array All-Sky Survey (LOTAAS) is an ongoing all northern sky survey for pulsars and transients. It is one of the first large scale pulsar surveys conducted at an observing frequency below 200 MHz. The unique set-up of the survey is the simultaneous formation of 222 beams for each survey pointing by coherently adding signals from the central 6 LOFAR stations. This represents the first SKA-like pulsar survey. As of 12 September 2017, the survey has completed 1456 pointings, more than two-thirds of the total. The survey has discovered 61 new pulsars via Fourier-based periodicity searches and a further 5 via single pulse searches. I present the survey approach and distinctive features including a discussion of an improved machine learning classifier used to identify the best candidates produced by the pipeline for further investigation. I present a summary of the discoveries so far including the first binary pulsar and the pulsar with the longest spin period of 23.5 s.
In this paper, a simplified lattice Boltzmann method (SLBM) without evolution of the distribution function is developed for simulating incompressible viscous flows. This method is developed from the application of fractional step technique to the macroscopic Navier-Stokes (N-S) equations recovered from lattice Boltzmann equation by using Chapman-Enskog expansion analysis. In SLBM, the equilibrium distribution function is calculated from the macroscopic variables, while the non-equilibrium distribution function is simply evaluated from the difference of two equilibrium distribution functions. Therefore, SLBM tracks the evolution of the macroscopic variables rather than the distribution function. As a result, lower virtual memories are required and physical boundary conditions could be directly implemented. Through numerical test at high Reynolds number, the method shows very nice performance in numerical stability. An accuracy test for the 2D Taylor-Green flow shows that SLBM has the second-order of accuracy in space. More benchmark tests, including the Couette flow, the Poiseuille flow as well as the 2D lid-driven cavity flow, are conducted to further validate the present method; and the simulation results are in good agreement with available data in literatures.
Laser-driven relativistic electrons can be focused onto a high-Z convertor for generating high-brightness γ-rays, which in turn can be used to induce photonuclear reactions. In this work, photo-transmutation of long-lived radionuclide 135Cs induced by laser–plasma–interaction-driven electron source is demonstrated using Geant4 simulation (Agostinelli et al., 2003 Nucl. Instrum. Meth. A506, 250). High-energy electron generation, bremsstrahlung, as well as photonuclear reaction are observed at four different laser intensities: 1020, 5 × 1020, 1021, and 5 × 1021 W/cm2. The transmutation efficiency depends on the laser intensity and target size. An optimum laser intensity, namely 1021 W/cm2, was found, with the corresponding photonuclear reaction yield reaching 108 J−1 of the laser energy. Laser-generated electrons can therefore be a promising tool for transmutation reactions. Potential application in nuclear waste management is suggested.
Vibrio cholerae O139 emerged as a causative agent of epidemic cholera in 1992 in India and Bangladesh, and was subsequently reported in China in 1993. The genetic relatedness and molecular characteristics of V. cholerae O139 in Guangdong Province, located in the southern coastal area of China, remains undetermined. In this study, we investigated 136 clinical V. cholerae O139 isolates from 1993 to 2013 in Guangdong. By conventional PCR, 123 (90·4%) isolates were positive for ctxB, ace and zot. Sequencing of the positive amplicons indicated 113 (91·7%) isolates possessed the El Tor allele of ctxB (genotype 3); seven carried the classical ctxB type (genotype 1) and three harboured a novel ctxB type (genotype 5). With respect to tcpA, 123 (90·4%) isolates were positive for the El Tor allele. In addition, pulsed-field gel electrophoresis (with NotI digestion) differentiated the isolates into clusters A and B. Cluster A contained seven of the non-toxigenic isolates from 1998 to 2000; another six non-toxigenic isolates (from 1998 and 2007) and all of the toxigenic isolates formed cluster B. Our results suggest that over a 20-year period, the predominant O139 clinical isolates have maintained a relatively tight clonal structure, although some genetic variance and shift has occurred. Our data highlight the persistence of toxigenic V. cholerae O139 in clinical settings in the southern coastal area of China.
Anthrax is still a severe public health problem and threat to human health. A cutaneous anthrax outbreak occurred in Jiangsu Province, a non-endemic anthrax region of eastern China, from July to August 2012. Epidemiological and laboratory investigation were initiated to trace the source of infection and identify the risk factors of the outbreak. On 25 July 2012, 17 persons were exposed to a sick cow, which had been imported from northeast China a few days previously. Of the 17 exposed, eight developed symptoms between 1 and 8 days and were diagnosed as cutaneous anthrax cases. Three main genes of Bacillus anthracis were detected from both human and cow meat samples, indicating that the outbreak was associated with this infected cow. A retrospective cohort study showed that contact with blood and presence of skin damage contributed to the case infection with B. anthracis. The outbreak highlights the need to enhance quarantine for imported livestock, which should have been vaccinated prior to importation, the significance of education for high-risk individuals, and training for primary healthcare workers even in anthrax-free areas.