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Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array’s (MWA) Phase II compact configuration offers us opportunities for both redundant calibration and sky-based calibration algorithms; using the two in tandem is a potential approach to mitigate calibration errors caused by inaccurate sky models. The MWA Epoch of Reionization (EoR) experiment targets three patches of the sky (dubbed EoR0, EoR1, and EoR2) with deep observations. Previous work in Li et al. (2018) and (2019) studied the effect of tandem calibration on the EoR0 field and found that it yielded no significant improvement in the power spectrum (PS) over sky-based calibration alone. In this work, we apply similar techniques to the EoR1 field and find a distinct result: the improvements in the PS from tandem calibration are significant. To understand this result, we analyse both the calibration solutions themselves and the effects on the PS over three nights of EoR1 observations. We conclude that the presence of the bright radio galaxy Fornax A in EoR1 degrades the performance of sky-based calibration, which in turn enables redundant calibration to have a larger impact. These results suggest that redundant calibration can indeed mitigate some level of model incompleteness error.
Little is known about the joint mental health effects of air pollution and tobacco smoking in low- and middle-income countries.
To investigate the effects of exposure to ambient fine particulate matter pollution (PM2.5) and smoking and their combined (interactive) effects on depression.
Multilevel logistic regression analysis of baseline data of a prospective cohort study (n=41785). The 3-year average concentrations of PM2.5 were estimated using US National Aeronautics and Space Administration satellite data, and depression was diagnosed using a standardised questionnaire. Three-level logistic regression models were applied to examine the associations with depression.
The odds ratio (OR) for depression was 1.09 (95% CI 1.01–1.17) per 10 μg/m3 increase in ambient PM2.5, and the association remained after adjusting for potential confounding factors (adjusted OR = 1.10, 95% CI 1.02–1.19). Tobacco smoking (smoking status, frequency, duration and amount) was also significantly associated with depression. There appeared to be a synergistic interaction between ambient PM2.5 and smoking on depression in the additive model, but the interaction was not statistically significant in the multiplicative model.
Our study suggests that exposure to ambient PM2.5 may increase the risk of depression, and smoking may enhance this effect.
We investigated the first presence of qnrA among Shigella sonnei clinical isolates in Jiangsu Province, China. The qnrA-positive isolates coexisted with the mutation in gyrA at codon 83, these isolates were resistant to nalidixic acid and 22·2% (2 of 9) of them were resistant to norfloxacin.
The E2F transcription factor family is distributed widely in eukaryotes and has been well studied among mammals. In the present study, the E2F transcription factor 4 (E2F4) gene was isolated from fat bodies of Antheraea pernyi and sequenced. E2F4 comprised a 795 bp open reading frame encoding a deduced amino acid sequence of 264 amino acid residues. The recombinant protein was expressed in Escherichia coli (Transetta DE3), and anti-E2F4 antibodies were prepared. The deduced amino acid sequence displayed significant homology to an E2F4-like protein from Bombyx mori L. Quantitative real-time polymerase chain reaction analysis revealed that E2F4 expression was highest in the integument, followed by the fat body, silk glands, and haemocytes. The expression of E2F4 was upregulated in larvae challenged by bacterial (Escherichia coli, Micrococcus luteus), viral (nuclear polyhedrosis virus), and fungal (Beauveria bassiana) pathogens. These observations indicated that E2F4 is an inducible protein in the immune response of A. pernyi and probably in other insects.
A series of catalytic reactions has been performed in our laboratory using olivine-type silicates (OTS) and SiC as catalysts for the conversion of carbon-containing molecules (such as acetylene, CO and methanol) to small organic molecules (C2H4, C3H3, CH3O) and also polycyclic aromatic hydrocarbons (PAHs). Experimentally, small-to-medium-sized gas-phase compounds such as PAHs, reaction intermediates and hydrocarbon compounds were detected in situ using the time-of-light mass-spectrometry technique. Solid deposition on the catalyst surface was examined by high-resolution transmission electron microscopy and thermo-gravimetric analysis techniques. Our laboratory results show that the conversion of acetylene to PAHs, the CO disproportionation reaction for producing CO2 and carbon deposition (graphitic and carbon nanostructures), and also the transformation of methanol to hydrocarbon compounds can easily be achieved with OTS as a catalyst. Furthermore, the conversion of acetylene to PAHs could also be achieved by SiC as the catalyst. It is proposed that these catalytic reactions mimic similar chemical processes in circumstellar envelopes (CSEs).
Lipases are ubiquitous enzymes in nature, which play a crucial role in fat metabolism by catalyzing the hydrolysis of triacylglycerol to free fatty acids and glycerol. However, reports concerning insect lipase are rare. In this study, we studied the expression and activity of a lipase-related protein from Antheraea pernyi (ApLRP). Recombinant ApLRP was expressed in Escherichia coli cells and used to raise rabbit anti-ApLRP polyclonal antibodies. ApLRP mRNA and protein expression were abundant in the midgut and malpighian tubules, respectively. After challenge with four different microorganisms (E. coli, Beauveria bassiana, Micrococcus luteus and nuclear polyhedrosis virus), the expression levels of ApLRP mRNA in midgut were inducted significantly compared with the control. The different pathogens induced different ApLRP gene expression patterns. The optimum temperature and pH for the enzyme's activity were 35°C and 7.0, respectively. ApLRP activity was stimulated in the presence of Mg2+, Na+, Ca2+ and b-mercaptoethanol; while Zn2+, Cu2+ and Fe3+ inhibited its activity. Detergents such as SDS, glycerol and Tween-20 increased the lipase activity by 20–30%. Our results indicated that ApLRP might play an important role in the innate immunity of insects.
Maize in Canada is grown mainly in the south-eastern part of the country. No comprehensive studies on Canadian maize yield levels have been done so far to analyse the barriers of obtaining optimal yields associated with cultivar, environmental stress and agronomic management practices. The objective of the current study was to use a modelling approach to analyse the gaps between actual and potential (determined by cultivar, solar radiation and temperature without any other stresses) maize yields in Eastern Canada. The CSM–CERES–Maize model in DSSAT v4·6 was calibrated and evaluated with measured data of seven cultivars under different nitrogen (N) rates across four sites. The model was then used to simulate grain yield levels defined as: yield potential (YP), water-limited (YW, rainfed), and water- and N-limited yields with N rates 80 kg/ha (YW, N-80N) and 160 kg/ha (YW, N-160N). The options were assessed to further increase grain yield by analysing the yield gaps related to water and N deficiencies. The CSM–CERES–Maize model simulated the grain yields in the experiments well with normalized root-mean-squared errors <0·20. The model was able to capture yield variations associated with varying N rates, cultivar, soil type and inter-annual climate variability. The seven calibrated cultivars used in the experiments were divided into three grades according to their simulated YP: low, medium and high. The simulation results for the 30-year period from 1981 to 2010 showed that the average YP was 15 000 kg/ha for cultivars with high yield potential. The YP is generally about 6000 kg/ha greater than the actual yield (YA) at each experimental site in Eastern Canada. Two-thirds of this gap between YP and YA is probably associated with water stress, as a gap of approximately 4000 kg/ha between the YW and the YP was simulated. This gap may be reduced through crop management, such as introducing irrigation to improve the distribution of available water during the growing season. The simulated yields indicated a gap of about 3000 and 1000 kg/ha between YW and YW,N-80N for cultivars with high YP and low YP, respectively. The gap between YW and YW,N-160N decreased to <2000 kg/ha for high Yp cultivars with little difference for the low Yp cultivars. The different yield gaps among cultivars suggest that cultivars with high YP require high N rates but cultivars with low YP may need only low N rates.
There is new evidence which identifies seasonal changes of the variability time scale in intraday variable (IDV) sources with refractive interstellar scintillation effects. Such a RISS model takes the annual change of the Earth's velocity relative to the scattering medium into account. In September 1998 we found a remarkable prolongation of the variability time scale in the IDV source 0917+624 with only small variations in flux density during a period of 5 days. This was explained as a seasonal effect, in which the velocity vector of the Earth and the interstellar medium nearly cancelled. In order to further investigate the applicability of the model for 0917+624, we performed an Effelsberg 6 cm-flux monitoring program over the course of one year. Since September 2000, the source appears to be remarkably inactive and yet (May 2001) no return to its normal, faster and stronger variability pattern is observed. Here, our observational results and a possible explanation for the current quiescence are presented.
Orbital-period variations of the neglected W UMa-type binary star, NY Lyr, were analyzed based on two newly determined eclipse times together with the others compiled from the literature. A cyclic oscillation with a period of 82.1 yr and an amplitude of 0.0247 d was discovered to be superimposed on a continuous period increase (dP/dt = +1.33 × 10−7 d yr−1). After the long-term period increase and the large-amplitude cyclic oscillation were removed from the O–C diagram, the residuals suggest that there is another small-amplitude period oscillation (A4 = 0.0053 d, P4 = 19.4 years) in the orbital period changes. As in the cases of AH Cnc and AD Cnc, both the continuous period increase and the two cyclic period oscillations make NY Lyr an interesting system to study in the future. In order to understand the evolutionary state of the binary system, new photometric and spectroscopic observations and a careful investigation on those data are needed.
In-depth analysis of eclipsing binary (EB) observational data collected for several decades can inform us about a lot of astrophysically interesting processes taking place in the systems. We have developed a wide-ranging method for the phenomenological modelling of eclipsing binary phase curves that enables us to combine even very disparate sources of phase information. This approach is appropriate for the processing of both standard photometric series of eclipses and data from photometric surveys of all kind. We conclude that mid-eclipse times, determined using the latest version of our “hi-fi” phenomenological light curve models, as well as their accuracy, are nearly the same as the values obtained using much more complex standard physical EB models.
Transoral rigid laryngoscopy with videostroboscopy is the most practical method to visualise the vocal folds. The optimal topical anaesthesia regimen for transoral rigid laryngoscopy has not yet been established.
To compare patient comfort and compliance with various topical anaesthetics for transoral rigid laryngoscopy.
Each of 10 patients received a random topical administration of either 2 per cent lidocaine gel, 1 per cent tetracaine gel or 1 per cent tetracaine solution, 10 minutes before undergoing rigid laryngoscopy with videostroboscopy. During follow-up laryngoscopies, the agent with the lowest mean visual analogue scale score for discomfort was then used to study the timing of topical anaesthetic application: the agent was given to the patient 5, 10 or 15 minutes before laryngoscopy (with the timing randomly selected).
Compared with lidocaine gel or tetracaine gel, laryngoscopy with topical tetracaine solution was more comfortable. There was a statistically significant difference in discomfort score between the 5 and 10 minute application groups, but not between the 10 and 15 minute groups.
The roles of hydrogen plasma radicals on passivation of several kinds of crystallized poly-Si thin films were investigated using optical emission spectroscopy (OES) combined with Hall mobility, Raman spectra, and absorption coefficient spectra. It was found that different kinds of hydrogen plasma radicals are responsible for passivation of dissimilar poly-Si crystallized by different method. Radicals Hα with lower energy are mainly responsible for passivating the poly-Si crystallized by solid phase crystallization (SPC) whose crystallization precursor was made by plasma enhanced chemical vapor deposition (PECVD). Higher energy radicals H* are more effective in passivating defects left over by Ni in poly-Si crystallized by Metal Induced Crystallization (MIC). The highest energy radicals Hβ and Hγ are needed to passivate the defects in poly-Si crystallized by SPC but whose precursor was made by low pressure CVD (LPCVD).
A technique to improve and accelerate aluminum induced crystallization (AIC) by hydrogen plasma is proposed in this paper. Raman spectroscopy and Secondary Ion Mass Spectrometry of crystallized poly-Si thin films show that hydrogen plasma radicals reduce the crystallization time of AIC. This technique shortens the annealing time from 10 hours to 4 hours and increases the Hall mobility from 22.1 cm2/V·s to 42.5 cm2/V·s. The possible mechanism of AIC assisted by hydrogen radicals will also be discussed.
Graphene, two-dimensional layers of sp2-bonded carbon, has many unique properties. In this paper, graphene is decorated with flower-like MnO2 nanostructures for the application in energy storage devices. The as-prepared graphene and MnO2 nano-flowers, which were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were assembled into an asymmetric supercapacitor. The specific capacitance of the graphene electrode reached 245 F/g at a charging current of 1 mA. The MnO2 nano-flowers which consisted of tiny rods with a diameter of less than 10 nm were coated onto the graphene electrodes by electrodeposition. The specific capacitance after the MnO2 deposition is 328 F/g at the charging current of 1 mA with an energy density of 11.4Wh/kg and power density of 25.8 kW/kg. This work suggests that our graphene-based electrodes can be a promising candidate for high-performance energy storage devices.
Genetic polymorphisms of the LMP/TAP gene coded by the HLA-II region may be associated with outcomes of HBV infection. We conducted a case-control study to test the hypothesis, including a persistent group of 155 patients with chronic hepatitis B and 36 healthy carriers, a recovered group of 165 individuals spontaneously recovered from HBV infection, and an uninfected group of 278 healthy normal controls. Genotypes of eight polymorphisms of the LMP/TAP gene were analysed by PCR–RFLP. A logistic regression model was used to analyse statistical differences in polymorphisms or haplotypes in different groups. Of the eight polymorphisms, two (TAP1 codon 637 and LMP7 codon 145) were observed to have statistically significant association with outcomes of HBV infection (P<0·05). The two-locus haplotype constructed with two such polymorphisms was analysed. The frequencies of haplotypes B (Asp-Lys), C (Gly-Gln), and D (Gly-Lys) were found to be increased significantly in the persistent group, compared to healthy controls (OR 2·26, 95% CI 1·62–3·15, P<0·001; OR 2·37, 95% CI 1·69–3·32, P<0·001; OR 4·38, 95% CI 1·78–10·77, P=0·001, respectively). The prevalence of haplotypes B (Asp-Lys), C (Gly-Gln), and D (Gly-Lys) were also significantly higher in the persistent infectious group than in the recovered group (OR 2·68, 95% CI 1·81–3·98, P<0·001; OR 2·40, 95% CI 1·62–3·55, P<0·001; OR 3·03, 95% CI 1·22–7·55, P=0·017, respectively). These findings indicated that genetic polymorphisms of the LMP/TAP gene might be an important factor in determining the outcome of HBV infection.
The rise-time of the pulse on the diode of the intense electron-beam accelerators (IEBA) is one of the important factors that affect the quality and characteristic of the output beam current of the IEBA. In this paper, effect of the transition section between the main switch and middle cylinder of strip spiral Blumlein line (SSBL) on the diode voltage of IEBA is analyzed in theory, based on the theoretical analysis of the wave propagation along the Blumlein pulse forming line (BPFL), the traveling time of the transition section has a great effect on the rise-time, the plateau-time, and the fall-time of the output voltage at the matching load. Furthermore, the operation of the whole accelerator consisting of the primary energy-storage capacitor, the Tesla transformer, a main switch, the transition section, BPFL, and a resistive load was simulated using a circuit-simulation code called PSpice, and the dependence of the output voltage on the inductance of the main switch and the transition section was obtained. It was found from the wave propagation theory and the circuit simulation using computer results that the wave traveling time of the transition section between the main switch and the middle cylinder of the SSBL influences considerably the rise-time, plateau-time, and fall-time of the voltage waveform at the matching load. In order to get an ideal square pulse voltage waveform at the matching load and to improve the electron beam quality of such an accelerator, the wave traveling time of the transition section should be designed as soon as possible. At last, a couple of contrastive experiments are performed on two kinds of IEBA. The experimental results agree with the theoretical analysis and simulated results.
The Experimental Advanced Superconducting Tokamak (EAST) has a major radius of R0 = 1.75 m and a midplane halfwidth of 0.5 m. It has been operated with a toroidal magnetic field B0 = 2 T and Ip ≤ 500 kA. The evolution of the plasma equilibrium is analysed between discharges by Equilibrium Fitting Code (EFIT). Limiter, single-null and double-null diverted configurations have been produced. A plasma elongation in the range 1.3 ≤ κ ≤ 1.9 and a triangularity in the range 0.1 ≤ δ ≤ 0.55 have been sustained. The operation space of elongated discharges is also presented based on the EAST database.