In centrifugal compressors, the identification of flow instability signals from experiments is a difficult problem owing to the nonlinear and non-stationary characteristics. Otherwise, the complicated asymmetric structure of the volute brings a huge challenge to the evolution and circumferential nonuniformity characteristics of the flow instabilities. This paper presents experimental and numerical investigations on internal flow field to understand the flow instability characteristics in a centrifugal compressor. Considering nonlinear and non-stationary signals, a method based on Fourier-transform and variational mode decomposition was introduced to analyse the flow instability characteristics. The Fourier spectrum results show that at 0.21kg/s of 80krpm, the pressure signal has a noticeable high-frequency fluctuation, which indicates that the compressor enters the flow instability state. The variational mode decomposition results show that before a surge, the compressor experiences different flow instability stages: the RI stage, the coexistence stage of RI and stall, and the stall stage. Moreover, obvious circumferential nonuniformity characteristics of flow instabilities were observed during the throttling process. RI first occurred at the 180° circumferential position and then the stall first appeared in the circumferential range of 60° to 240°. The simulation results that it is because that the asymmetric volute causes the adverse pressure gradient inside the impeller passage and a high-pressure region (120°–240°) at the upstream of the impeller inlet. Under this combined action of the two, the effect region of tip leakage vortex expands the upstream of the impeller inlet. Meanwhile, the tip leakage vortex core migrates to a lower span of blades. This study demonstrates the ability to analyse nonlinear and non-stationary signals from a centrifugal compressor via variational mode decomposition, and provides a useful guidance for the identification of flow instability signals.

The satellite attitude control system (SACS) is a complicated system. In order to reflect the relationship among different components in SACS and analyse the impact of component faults on system performance, a complete simulation platform of the SACS based on Simulink is built in this paper. With the embedding of the specific reaction flywheel, gyroscope and earth sensor model, and the design of the controller based on the quaternion feedback, the simulation platform can not only simulate the real SACS at the component level, but it can also realise the injection of component faults for analysing the system performance. Simulations are conducted to verify the performance of the simulation platform. Simulation results show that this simulation platform has the ability to accurately reflect the control performance of the SACS, and the output accuracy of the component model is high. The research results reveal that this simulation platform can provide model support for verifying the algorithm of fault diagnosis, prediction and tolerant control of the SACS. This simulation platform is easy to use and can be expanded and improved.

Previous studies have revealed associations of meteorological factors with tuberculosis (TB) cases. However, few studies have examined their lag effects on TB cases. This study was aimed to analyse nonlinear lag effects of meteorological factors on the number of TB notifications in Hong Kong. Using a 22-year consecutive surveillance data in Hong Kong, we examined the association of monthly average temperature and relative humidity with temporal dynamics of the monthly number of TB notifications using a distributed lag nonlinear models combined with a Poisson regression. The relative risks (RRs) of TB notifications were >1.15 as monthly average temperatures were between 16.3 and 17.3 °C at lagged 13–15 months, reaching the peak risk of 1.18 (95% confidence interval (CI) 1.02–1.35) when it was 16.8 °C at lagged 14 months. The RRs of TB notifications were >1.05 as relative humidities of 60.0–63.6% at lagged 9–11 months expanded to 68.0–71.0% at lagged 12–17 months, reaching the highest risk of 1.06 (95% CI 1.01–1.11) when it was 69.0% at lagged 13 months. The nonlinear and delayed effects of average temperature and relative humidity on TB epidemic were identified, which may provide a practical reference for improving the TB warning system.

Research on flight emissions at airports is very important for environmental policymaking. This study analysed the trend of aircraft air pollutant emissions at mainland China airports from 1990 to 2017, mainly focusing on standard landing and take-off (LTO) cycles. Total flight movements increased 29-fold from 1990 to 2017 at Chinese airports. Over the same period, the emissions of NOx, SOx, CO, hydrocarbons (HC), and particulate matter (PM) increased 46, 27, 12, 5, and 4 times, respectively. Emissions at the 216 public airports showed a growth trend. It was estimated that in 2017, Chinese airports emitted 12,875 kilotons of CO2, 59 kilotons of NOx, 3 kilotons of SOx, 38 kilotons of CO, 5 kilotons of HC, and 0.4 kilotons of PM. The largest 30 airports produced 68.2% of the total emissions. Emissions from B737-800, A320, A321, B737-700, A330-300, and A319 aircraft accounted for more than 75% of aircraft LTO emissions at Chinese airports in 2017. Results show that average emissions per passenger have decreased for CO2, CO, HC, SOx, PM, and NOx from 1990 to 2017.

Severe fever with thrombocytopenia syndrome (SFTS) is a disease with a high case-fatality rate that is caused by infection with the SFTS virus (SFTSV). Five electronic databases were systematically searched to identify relevant articles published from 1 January 2011 to 1 December 2019. The pooled rates with 95% confidence interval (CI) were calculated by a fixed-effect or random-effect model analysis. The results showed that 92 articles were included in this meta-analysis. For the confirmed SFTS cases, the case-fatality rate was 0.15 (95% CI 0.11, 0.18). Two hundred and ninety-six of 1384 SFTS patients indicated that they had been bitten by ticks and the biting rate was 0.21 (95% CI 0.16, 0.26). The overall pooled seroprevalence of SFTSV antibodies among the healthy population was 0.04 (95% CI 0.03, 0.05). For the overall seroprevalence of SFTSV in animals, the seroprevalence of SFTSV was 0.25 (95% CI 0.20, 0.29). The infection rate of SFTSV in ticks was 0.08 (95% CI 0.05, 0.11). In conclusion, ticks can serve as transmitting vectors of SFTSVs and reservoir hosts. Animals can be infected by tick bites, and as a reservoir host, SFTSV circulates continuously between animals and ticks in nature. Humans are infected by tick bites and direct contact with patient secretions.

Klebsiella pneumoniae is a common pathogen associated with nosocomial infections and is characterised serologically by capsular polysaccharide (K) and lipopolysaccharide O antigens. We surveyed a total of 348 non-duplicate K. pneumoniae clinical isolates collected over a 1-year period in a tertiary care hospital, and determined their O and K serotypes by sequencing of the wbb Y and wzi gene loci, respectively. Isolates were also screened for antimicrobial resistance and hypervirulent phenotypes; 94 (27.0%) were identified as carbapenem-resistant (CRKP) and 110 (31.6%) as hypervirulent (hvKP). isolates fell into 58 K, and six O types, with 92.0% and 94.2% typeability, respectively. The predominant K types were K14K64 (16.38%), K1 (14.66%), K2 (8.05%) and K57 (5.46%), while O1 (46%), O2a (27.9%) and O3 (11.8%) were the most common. CRKP and hvKP strains had different serotype distributions with O2a:K14K64 (41.0%) being the most frequent among CRKP, and O1:K1 (26.4%) and O1:K2 (17.3%) among hvKP strains. Serotyping by gene sequencing proved to be a useful tool to inform the clinical epidemiology of K. pneumoniae infections and provides valuable data relevant to vaccine design.

We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for the newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. MeerKAT is a high-gain ( ${\sim}2.8\,\mbox{K Jy}^{-1}$ ) low-system temperature ( ${\sim}18\,\mbox{K at }20\,\mbox{cm}$ ) radio array that currently operates at 580–1 670 MHz and can produce tied-array beams suitable for pulsar observations. This paper presents results from the MeerTime Large Survey Project and commissioning tests with PTUSE. Highlights include observations of the double pulsar $\mbox{J}0737{-}3039\mbox{A}$ , pulse profiles from 34 millisecond pulsars (MSPs) from a single 2.5-h observation of the Globular cluster Terzan 5, the rotation measure of Ter5O, a 420-sigma giant pulse from the Large Magellanic Cloud pulsar PSR $\mbox{J}0540{-}6919$ , and nulling identified in the slow pulsar PSR J0633–2015. One of the key design specifications for MeerKAT was absolute timing errors of less than 5 ns using their novel precise time system. Our timing of two bright MSPs confirm that MeerKAT delivers exceptional timing. PSR $\mbox{J}2241{-}5236$ exhibits a jitter limit of $<4\,\mbox{ns h}^{-1}$ whilst timing of PSR $\mbox{J}1909{-}3744$ over almost 11 months yields an rms residual of 66 ns with only 4 min integrations. Our results confirm that the MeerKAT is an exceptional pulsar telescope. The array can be split into four separate sub-arrays to time over 1 000 pulsars per day and the future deployment of S-band (1 750–3 500 MHz) receivers will further enhance its capabilities.

Design fixation refers to the designers’ inability to avoid becoming stuck with preexisting ideas in order to generate new ones. With the recent fast advancements and developments, XR has emerged as a powerful promising technology that can shed new light on this issue. Consequently, this paper aims at: (1) investigating the underlying mechanisms of design fixation as reported in literature; (2) exploring the state-of-art in the use of XR technology in design; and (3) identifying ways to mitigate design fixation by employing XR technology.

Many studies showed the differences in subjective response to sexual stimuli between heterosexual and homosexual men. However, the underlying neurobiological factors of sexual orientation are largely unknown. We addressed the question what is the major attribution of the expected differences in brain activation, i.e. neural circuits or different cognitive process. Twenty-eight healthy male volunteers, 14 heterosexuals and 14 homosexuals, were scanned by functional Magnetic Resonance Imaging while subjects were viewing different types of stimuli, i.e. heterosexual couple stimuli (HCS), gay couple stimuli (GCS), lesbian couple stimuli (LCS) and neutral stimuli (NS). SPM02 was used for data analysis. Rating of sexual attractiveness was assessed. Subjective sexual arousal was induced by HCS and GCS in heterosexual and homosexual men, respectively. And sexual disgust was induced by GCS and LCS in heterosexual and homosexual men, respectively. As compared to viewing NS, viewing sexual stimuli induced significant different brain activations most of which had characteristic for cognitive process. These observations suggested that different cognitive pattern was major attribution of different subjective response to sexual stimuli between heterosexual and homosexual men.

The treatment of refractory schizophrenia has been a clinical challenge for most psychiatrists. The possible mechanism of the refractory schizophrenia included diagnostic errors, medical conditions and brain dysgensis. Here, we described a patient with childhood-onset schizophrenia who had severe psychiatric symptoms such as auditory hallucination and persecutory delusion and so on. We reexamined all his possible medical conditions and found the patient had an abnormal enlarged Cavus Septum Pellucidum (CSP) combined with Cavum Vergae (CV) (maximum length>30 mm). Some reports suggested that abnormal CSP(length>6 mm) has an significant association with schizophrenia. However, abnormally large CSP or CSP/CV and related prognosis were reported rarely. This case suggested that abnormally enlarged CSP or CSP/CV may lead to schizophrenia and worse prognosis.

Social phobia is increasingly recognized as a prevalent and socially impairing mental disorder. However, little data is available regarding the general and disease-specific impairments and disabilities associated with social phobia. Furthermore, most studies have not controlled for the confounding effects of comorbid conditions.

This study investigates: (a) the generic quality of life; (b) work productivity; and, (c) various other disorder-specific social impairments in current cases with pure (n = 65), comorbid (n = 51) and subthreshold (n = 34) DSM-IIIR social phobia as compared to controls with no social phobia (subjects with a history of herpes infections).

Social phobia cases reported a mean illness duration of 22.9 years with onset in childhood or adolescence. Current quality of life, as assessed by the SF-36, was significantly reduced in all social phobia groups, particularly in the scales measuring vitality, general health, mental health, role limitations due to emotional health, and social functioning. Comorbid cases revealed more severe reductions than pure and subthreshold social phobics. Findings from the Liebowitz self-rated disability scale indicated that: (a) social phobia affects most areas of life, but in particular education, career, and romantic relationship; (b) the presence of past and current comorbid conditions increases the frequency of disease-specific impairments; and, (c) subthreshold social phobia revealed slightly lower overall impairments than comorbid social phobics. Past week work productivity of social phobics was significantly diminished as indicated by: (a) a three-fold higher rate of unemployed cases; (b) elevated rates of work hours missed due to social phobia problems; and, (c) a reduced work performance.

Overall, these findings underline that social phobia in our sample of adults, whether comorbid, subthreshold, or pure was a persisting and impairing condition, resulting in considerable subjective suffering and negative impact on work performance and social relationships. The current disabilities and impairments were usually less pronounced than in the past, presumably due to adaptive behaviors in life style of the respondents. Data also confirmed that social phobia is poorly recognized and rarely treated by the mental health system.

What explains public attitudes towards a former aggressor state? Conventional wisdom would suggest the prevalence of negative sentiments rooted in historical hatred. In this article we contend that when individuals are proficient in a foreign language—e.g. a lingua franca—they have an alternative channel through which they are exposed to positive narratives put forth by other parties regarding the former aggressor state. And as a result, their attitudes towards the former aggressor state are more positive than those held by their linguistically limited counterparts. To test our argument, we focus on public attitudes towards the Japanese in Mainland China, Singapore, and Taiwan—three Chinese-ethnic majority political units that experienced Japanese aggression leading up to and during World War II. Using survey data, we demonstrate that individuals who are proficient in the English language are much more likely to hold positive attitudes of the Japanese. These results are robust even when we consider whether some individuals are predisposed to being cosmopolitan; whether some individuals have more opportunities to learn English; and whether the linguistic effects are symptomatic of American soft power.

The aim of this research was to identify variation in the yak lipin-1 gene (LPIN1) and determine whether this variation affects milk traits. PCR-single stranded conformational polymorphism (PCR-SSCP) analysis was used to detect variation in the 5′ untranslated region of LPIN1 in 500 yaks from four populations: Tianzhu white yaks, Qinghai yaks, wild × domestic-cross yaks and Gannan yaks. Four unique PCR-SSCP patterns, representing four different DNA sequence variants (named A, B, C and D), were observed. These contained six single nucleotide polymorphisms. Female Gannan yaks with BC genotype produced milk with a higher fat content (P < 0.001) and total milk solids (P < 0.001), than those with the AA, AB and BB genotypes. These results would suggest that LPIN1 is having an effect on yak milk fat synthesis.

We report a significant advance in thermally insulating transparent materials: silica-based monoliths with controlled porosity which exhibit the transparency of windows in combination with a thermal conductivity comparable to aerogels.

The lack of transparent, thermally insulating windows leads to substantial heat loss in commercial and residential buildings, which accounts for ~4.2% of primary US energy consumption annually. The present study provides a potential solution to this problem by demonstrating that ambiently dried silica aerogel monoliths, i.e., ambigels, can simultaneously achieve high optical transparency and low thermal conductivity without supercritical drying. A combination of tetraethoxysilane, methyltriethoxysilane, and post-gelation surface modification precursors were used to synthesize ambiently dried materials with varying pore fractions and pore sizes. By controlling the synthesis and processing conditions, 0.5–3 mm thick mesoporous monoliths with transmittance >95% and a thermal conductivity of 0.04 W/(m K) were produced. A narrow pore size distribution, <15 nm, led to the excellent transparency and low haze, while porosity in excess of 80% resulted in low thermal conductivity. A thermal transport model considering fractal dimension and phonon-boundary scattering is proposed to explain the low effective thermal conductivity measured. This work offers new insights into the design of transparent, energy saving windows.

A systematic review and network meta-analysis were conducted to assess the relative efficacy of internal or external teat sealants given at dry-off in dairy cattle. Controlled trials were eligible if they assessed the use of internal or external teat sealants, with or without concurrent antimicrobial therapy, compared to no treatment or an alternative treatment, and measured one or more of the following outcomes: incidence of intramammary infection (IMI) at calving, IMI during the first 30 days in milk (DIM), or clinical mastitis during the first 30 DIM. Risk of bias was based on the Cochrane Risk of Bias 2.0 tool with modified signaling questions. From 2280 initially identified records, 32 trials had data extracted for one or more outcomes. Network meta-analysis was conducted for IMI at calving. Use of an internal teat sealant (bismuth subnitrate) significantly reduced the risk of new IMI at calving compared to non-treated controls (RR = 0.36, 95% CI 0.25–0.72). For comparisons between antimicrobial and teat sealant groups, concerns regarding precision were seen. Synthesis of the primary research identified important challenges related to the comparability of outcomes, replication and connection of interventions, and quality of reporting of study conduct.

A systematic review and network meta-analysis were conducted to assess the relative efficacy of antimicrobial therapy given to dairy cows at dry-off. Eligible studies were controlled trials assessing the use of antimicrobials compared to no treatment or an alternative treatment, and assessed one or more of the following outcomes: incidence of intramammary infection (IMI) at calving, incidence of IMI during the first 30 days in milk (DIM), or incidence of clinical mastitis during the first 30 DIM. Databases and conference proceedings were searched for relevant articles. The potential for bias was assessed using the Cochrane Risk of Bias 2.0 algorithm. From 3480 initially identified records, 45 trials had data extracted for one or more outcomes. Network meta-analysis was conducted for IMI at calving. The use of cephalosporins, cloxacillin, or penicillin with aminoglycoside significantly reduced the risk of new IMI at calving compared to non-treated controls (cephalosporins, RR = 0.37, 95% CI 0.23–0.65; cloxacillin, RR = 0.55, 95% CI 0.38–0.79; penicillin with aminoglycoside, RR = 0.42, 95% CI 0.26–0.72). Synthesis revealed challenges with a comparability of outcomes, replication of interventions, definitions of outcomes, and quality of reporting. The use of reporting guidelines, replication among interventions, and standardization of outcome definitions would increase the utility of primary research in this area.

We conducted a systematic review and network meta-analysis to determine the comparative efficacy of antibiotics used to control bovine respiratory disease (BRD) in beef cattle on feedlots. The information sources for the review were: MEDLINE®, MEDLINE In-Process and MEDLINE® Daily, AGRICOLA, Epub Ahead of Print, Cambridge Agricultural and Biological Index, Science Citation Index, Conference Proceedings Citation Index – Science, the Proceedings of the American Association of Bovine Practitioners, World Buiatrics Conference, and the United States Food and Drug Administration Freedom of Information New Animal Drug Applications summaries. The eligible population was weaned beef cattle raised in intensive systems. The interventions of interest were injectable antibiotics used at the time the cattle arrived at the feedlot. The outcome of interest was the diagnosis of BRD within 45 days of arrival at the feedlot. The network meta-analysis included data from 46 studies and 167 study arms identified in the review. The results suggest that macrolides are the most effective antibiotics for the reduction of BRD incidence. Injectable oxytetracycline effectively controlled BRD compared with no antibiotics; however, it was less effective than macrolide treatment. Because oxytetracycline is already commonly used to prevent, control, and treat BRD in groups of feedlot cattle, the use of injectable oxytetracycline for BRD control might have advantages from an antibiotic stewardship perspective.