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The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together
programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories.
Seasonal autoregressive-integrated moving average (SARIMA) has been widely used to model and forecast incidence of infectious diseases in time-series analysis. This study aimed to model and forecast monthly cases of hand, foot and mouth disease (HFMD) in China. Monthly incidence HFMD cases in China from May 2008 to August 2018 were analysed with the SARIMA model. A seasonal variation of HFMD incidence was found from May 2008 to August 2018 in China, with a predominant peak from April to July and a trough from January to March. In addition, the annual peak occurred periodically with a large annual peak followed by a relatively small annual peak. A SARIMA model of SARIMA (1, 1, 2) (0, 1, 1)12 was identified, and the mean error rate and determination coefficient were 16.86% and 94.27%, respectively. There was an annual periodicity and seasonal variation of HFMD incidence in China, which could be predicted well by a SARIMA (1, 1, 2) (0, 1, 1)12 model.
Starch digestion in the small intestines of the dairy cow is low, to a large extent, due to a shortage of syntheses of α-amylase. One strategy to improve the situation is to enhance the synthesis of α-amylase. The mammalian target of rapamycin (mTOR) signalling pathway, which acts as a central regulator of protein synthesis, can be activated by leucine. Our objectives were to investigate the effects of leucine on the mTOR signalling pathway and to define the associations between these signalling activities and the synthesis of pancreatic enzymes using an in vitro model of cultured Holstein dairy calf pancreatic tissue. The pancreatic tissue was incubated in culture medium containing l-leucine for 3 h, and samples were collected hourly, with the control being included but not containing l-leucine. The leucine supplementation increased α-amylase and trypsin activities and the messenger RNA expression of their coding genes (P <0.05), and it enhanced the mTOR synthesis and the phosphorylation of mTOR, ribosomal protein S6 kinase 1 and eukaryotic initiation factor 4E-binding protein 1 (P <0.05). In addition, rapamycin inhibited the mTOR signal pathway factors during leucine treatment. In sum, the leucine regulates α-amylase and trypsin synthesis in dairy calves through the regulation of the mTOR signal pathways.
Seasonal autoregressive integrated moving average (SARIMA) has been used to model nationwide tuberculosis (TB) incidence in other countries. This study aimed to characterise monthly TB notification rate in China. Monthly TB notification rate from 2005 to 2017 was used. Time-series analysis was based on a SARIMA model and a hybrid model of SARIMA-generalised regression neural network (GRNN) model. A decreasing trend (3.17% per years, P < 0.01) and seasonal variation of TB notification rate were found from 2005 to 2016 in China, with a predominant peak in spring. A SARIMA model of ARIMA (0,1,1) (0,1,1)12 was identified. The mean error rate of the single SARIMA model and the SARIMA–GRNN combination model was 6.07% and 2.56%, and the determination coefficient was 0.73 and 0.94, respectively. The better performance of the SARIMA–GRNN combination model was further confirmed with the forecasting dataset (2017). TB is a seasonal disease in China, with a predominant peak in spring, and the trend of TB decreased by 3.17% per year. The SARIMA–GRNN model was more effective than the widely used SARIMA model at predicting TB incidence.
Using the spectroscopic distances of over 0.12 million A-type stars selected from the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC), we map their three-dimensional number density distributions in the Galaxy. These stellar number density maps allow an investigation of the Galactic young age thin disk structure with no a priori assumptions about the functional form of its components. The data show strong evidence for a significant flaring young disk. A more detail analysis show that the stellar flaring have different behaviours between the Northern and the Southern Galactic disks. The maps also reveal spatially coherent, kpc-scale stellar substructure in the thin disk. Finally, we detect the Perseus arm stellar overdensity at R ~ 10 kpc.
We derive the mean velocity components at various Galactocentric radii from 8 to 14 kpc using about 40,000 red clump stars observed in the LAMOST survey. We find that the vertical bulk motion for younger red clump stars are significantly larger than that for the older red clump stars. This is likely the kinematical feature of the Galactic warp around its line-of-node, which is located close to the Galactic anti-center region. It is evident that the warp are mainly contributed by the younger stars rather than the older stars. The age variation in the vertical kinematics favors a formation scenario where the Galactic warp is originated from infalling misaligned gas.
While oral antidepressants reach efficacy after weeks, single-dose intravenous (i.v.) ketamine has rapid, yet time-limited antidepressant effects. We aimed to determine the efficacy and safety of single-dose i.v. ketamine augmentation of escitalopram in major depressive disorder (MDD).
Thirty outpatients with severe MDD (17-item Hamilton Rating Scale for Depression total score ⩾24) were randomized to 4 weeks double-blind treatment with escitalopram 10 mg/day+single-dose i.v. ketamine (0.5 mg/kg over 40 min) or escitalopram 10 mg/day + placebo (0.9% i.v. saline). Depressive symptoms were measured using the Montgomery–Asberg Depression Rating Scale (MADRS) and the Quick Inventory of Depressive Symptomatology – Self-Report (QIDS-SR). Suicidal ideation was evaluated with the QIDS-SR item 12. Adverse psychopathological effects were measured with the Brief Psychiatric Rating Scale (BPRS)-positive symptoms, Young Mania Rating Scale (YMRS) and Clinician Administered Dissociative States Scale (CADSS). Patients were assessed at baseline, 1, 2, 4, 24 and 72 h and 7, 14, 21 and 28 days. Time to response (⩾50% MADRS score reduction) was the primary outcome.
By 4 weeks, more escitalopram + ketamine-treated than escitalopram + placebo-treated patients responded (92.3% v. 57.1%, p = 0.04) and remitted (76.9% v. 14.3%, p = 0.001), with significantly shorter time to response [hazard ratio (HR) 0.04, 95% confidence interval (CI) 0.01–0.22, p < 0.001] and remission (HR 0.11, 95% CI 0.02–0.63, p = 0.01). Compared to escitalopram + placebo, escitalopram + ketamine was associated with significantly lower MADRS scores from 2 h to 2 weeks [(peak = 3 days–2 weeks; effect size (ES) = 1.08–1.18)], QIDS-SR scores from 2 h to 2 weeks (maximum ES = 1.27), and QIDS-SR suicidality from 2 to 72 h (maximum ES = 2.24). Only YMRS scores increased significantly with ketamine augmentation (1 and 2 h), without significant BPRS or CADSS elevation.
Single-dose i.v. ketamine augmentation of escitalopram was safe and effective in severe MDD, holding promise for speeding up early oral antidepressant efficacy.
With the velocity de-projection technique, we derived the averaged 3 dimensional local velocity distribution using only the line-of-sight velocity for the 200,000 FGK type main-sequence stars from the LAMOST DR1 data. Taking the effective temperature as a proxy for age, we investigate the variation of the velocity distribution as a function of Teff and disk height within 100 < |z| < 500 pc. Using the mean velocities of the cool stars, we derive the solar motion of (U⊙, V⊙, W⊙)=(9.58±2.39, 10.52±1.96, 7.01±1.67) kms−1 with respect to the local standard of rest (LSR). Moreover, we find that the stars with Teff > 6000 K show a net asymmetric motion of 〈U〉~2 kms−1 and 〈W〉~3 kms−1 compared to the stars with Teff < 6000 K. And their azimuthal velocity increases when |z| increases. The asymmetric motion in the warmer stars is likely because they are too young and not completely relaxed.
We show that redshift-space distortions of galaxy correlations have a strong effect on correlation functions with the signature of the Baryon Acoustic Oscillations (BAO). Near the line of sight, the features become sharper as a result of redshift-space distortions. We analyze the SDSS DR7 main-galaxy sample (MGS), splitting the sample into slices 2.5 deg on the sky in various rotations. Measuring 2D correlation functions in each slice, we do see a sharp bump along the line of sight. Using Mexican-hat wavelets, we localize it to (110 ± 10) h − 1 Mpc and estimate its significance at about 4σ.
To study the interactive influence of implanted nano platinum black electrodes (as compared with pure platinum electrodes) on rabbit orbicularis oculi muscle morphology and function.
The influence of the two types of electrode on the orbicularis oculi muscle was monitored in a rabbit model of facial paralysis. Biological electric current and exciting current were administered to biological tissue, and morphological and functional changes were identified. Changes in orbicularis oculi muscle contraction, electrode configuration and performance associated with long-term electrical stimulation were observed over 28 days of implantation.
The nano platinum black electrode was superior to the pure platinum electrode in the following aspects: morphology and functionality, electrical excitation function of the orbicularis oculi muscle (as assessed by electromyography), muscle contraction function and biological tissue changes. Furthermore, the nano platinum black electrode features had good stability.
Microelectrode surface modification with nano platinum black can effectively increase the microelectrode surface area and improve electrode performance, and is associated with good tissue compatibility.
The transmission of haemorrhagic fever with renal syndrome (HFRS) is deeply influenced by the reservoir and hantavirus prevalence rate. In this study, a surveillance on human HFRS cases, relative rodent abundance, and hantavirus infection prevalence was conducted in Shaanxi province, China, during 1984–2012. A generalized linear model with Poisson-distributed residuals and a log link was used to quantify the relationship between reservoir, virus and HFRS cases. The result indicated that there was a significant association of HFRS incidence with relative rodent density and the prevalence rate. This research provides evidence that the changes of infection prevalence in the reservoir could lead directly to the emergence of a new epidemic. It was concluded that the measurement of a number of these variables could be used in disease surveillance to give useful advance warning of potential disease epidemics.
Parrots are one of the most popular pet birds in China, and can harbour Chlamydia which has significance for human and animal health. We investigated, by indirect haemagglutination assay, the seroprevalence of Chlamydia infection in four species of parrots, namely budgerigars (Melopsittacus undulatus), lovebirds (Agapornis sp.), cockatiels (Nymphicus hollandicus) and Alexandrine parakeets (Psittacula eupatria) that were collected from Weifang and Beijing cities, North China and explored the association between potential risk factors and chlamydial seropositivity. We further determined the genotype of Chlamydia in 21 fresh faecal samples based on the ompA sequence by reconstruction of phylogenetic relationships. Of the 311 parrots examined, 35·37% (95% confidence interval 30·06–40·68) were seropositive, and species, gender, age, season and geographical location were identified as risk factors. Two PCR-positive samples represented Chlamydia psittaci genotype A. The occurrence of C. psittaci genotype A in the droppings of two pet parrots in China suggests potential environmental contamination with Chlamydiaceae and may raise a public health concern.
A study of 7,388 consecutive patients after hepatic resection between 2011 and 2012 identified hepatolithiasis, cirrhosis, and intraoperative blood transfusion as the only independent risk factors of both incisional and organ/space surgical site infection (SSI). Patients with these conditions should be cared for with caution to lower SSI rates.
Millions of medical implants and devices (e.g., screws, plates, and pins) are used each year worldwide in surgery, and traditionally the components have been limited to permanent metals (e.g., stainless steel, titanium alloys) and polyester-based absorbable polymers. Because of clinical problems associated with these traditional materials, a novel class of biodegradable metallic materials, i.e., magnesium-based alloys, attracted great attention and clinical interests. Magnesium (Mg) is particularly attractive for load-bearing orthopedic applications because it has comparable modulus and strength to cortical bone. Controlling the interface of Mg with the biological environment, however, is the key challenge that currently limits this biodegradable metal for broad applications in medical devices and implants. This paper will particularly focus on creating nanostructured interface between the biodegradable metallic implant and surrounding tissue for the dual purposes of (1) mediating the degradation of the metallic implants and (2) simultaneously enhancing bone tissue regeneration and integration. Nanophase hydroxyapatite (nHA) is an excellent candidate as a coating material due to its osteoconductivity that has been widely reported. Applying nHA coatings or nHA containing composite coatings on Mg alloys is therefore promising in serving the needed dual functions. The composite of nHA and poly(lactic-co-glycolic acid) (PLGA) as a dual functional interface provides additional benefits for medical implant applications. Specifically, the polymer phase promotes interfacial adhesion between the nHA and Mg, and the degradation products of PLGA and Mg neutralize each other. Our results indicate that nHA and nHA/PLGA coatings slow down Mg degradation rate and enhance adhesion of bone marrow stromal cells, thus promising as the next-generation multifunctional implant materials. Further optimization of the coatings and their interfacial properties are still needed to bring them into clinical applications.
Varicella accounts for substantial morbidities and remains a public health issue worldwide, especially in children. Little is known about the effect of meteorological variables on varicella infection risk for children. This study described the epidemiology of paediatric varicella notifications in Hong Kong from 2004 to 2010, and explored the association between paediatric varicella notifications in children aged <18 years and various meteorological factors using a time-stratified case-crossover model, with adjustment of potential confounding factors. The analysis found that daily mean temperature, atmospheric pressure and Southern Oscillation Index (SOI) were positively associated with paediatric varicella notifications. We found that an interquartile range (IQR) increase in temperature (8·38°C) at lag 1 day, a 9·50 hPa increase in atmospheric pressure for the current day, and a 21·91 unit increase in SOI for the current day may lead to an increase in daily cases of 5·19% [95% confidence interval (CI) 1·90–8·58], 5·77% (95% CI 3·01–8·61), and 4·32% (95% CI 2·98–5·68), respectively. An IQR increase in daily relative humidity (by 11·96%) was associated with a decrease in daily paediatric varicella (−2·79%, 95% CI −3·84 to −1·73). These findings suggest that meteorological factors might be important predictors of paediatric varicella infection in Hong Kong.
Previous studies support Beck's cognitive model of vulnerability to depression. However, the relationship between his cognitive triad and other clinical features and risk factors among those with major depression (MD) has rarely been systematically studied.
The three key cognitive symptoms of worthlessness, hopelessness and helplessness were assessed during their lifetime worst episode in 1970 Han Chinese women with recurrent MD. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression.
Compared to patients who did not endorse the cognitive trio, those who did had a greater number of DSM-IV A criteria, more individual depressive symptoms, an earlier age at onset, a greater number of episodes, and were more likely to meet diagnostic criteria for melancholia, postnatal depression, dysthymia and anxiety disorders. Hopelessness was highly related to all the suicidal symptomatology, with ORs ranging from 5.92 to 6.51. Neuroticism, stressful life events (SLEs) and a protective parental rearing style were associated with these cognitive symptoms.
During the worst episode of MD in Han Chinese women, the endorsement of the cognitive trio was associated with a worse course of depression and an increased risk of suicide. Individuals with high levels of neuroticism, many SLEs and high parental protectiveness were at increased risk for these cognitive depressive symptoms. As in Western populations, symptoms of the cognitive trio appear to play a central role in the psychopathology of MD in Chinese women.
In recent years, human leptospirosis has been reported in Jinping and Liping counties, Guizhou province, but the leptospires have never been isolated. To track the source of infection and understand the aetiological characteristics, we performed surveillance for field mice carriage of leptospirosis in 2011. Four strains of leptospire were isolated from Apodemus agrarius. PCR confirmed the four isolates as pathogenic. Multiple-locus variable-number tandem repeat analysis (MLVA) showed that the four strains were closely related to serovar Lai strain 56601 belonging to serogroup Icterohaemorrhagiae, which is consistent with the antibody detection results from local patients. Furthermore, the diversity of leptospiral isolates from different hosts and regions was demonstrated with MLVA. Our results suggest that A. agrarius may be the main carrier of Leptospira in Jinping and Liping counties, and the serogroup Icterohaemorrhagiae serovar may be the epidemic serogroup of Leptospira. This will contribute to the control and prevention of leptospirosis in these localities.