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Despite the wide recognition of language teacher educators’ contributions in the field of Teaching English to Speakers of Other Languages (TESOL), research on language teacher educators has only picked up the pace in the last decade, shedding light on their cognition, practices, and identities in relation to various personal, interpersonal, and contextual factors. This article provides a systematic and critical review of 69 empirical studies on university-based TESOL teacher educators from 2010 and 2020. A methodological review was also conducted to analyze the different research approaches employed by previous researchers. A synthesis of the identified research led to four major themes, namely: (1) a general professional state (including responsibilities, challenges and quality), (2) professional engagement (including teaching, practicum supervision, and research and publishing), (3) cognition (including beliefs, knowledge, and expertise), as well as (4) continuous learning and identity development. Through a critical discussion of the themes, the review argues against the implicit yet powerful discourse that characterizes language teacher educators as ‘supermen/superwomen’ and emphasizes the need to humanize them as whole people by recognizing their unique strengths and struggles as well as diverse learning needs. The review also proposes a new research agenda to stimulate and deepen future investigations on language teacher educators in TESOL.
We numerically investigate turbulent Rayleigh–Bénard convection with gas bubbles attached to the hot plate, mimicking a core feature in electrolysis, catalysis or boiling. The existence of bubbles on the plate reduces the global heat transfer due to the much lower thermal conductivity of gases as compared with liquids and changes the structure of the boundary layers. The numerical simulations are performed in three dimensions at Prandtl number $\mbox{Pr}=4.38$ (water) and Rayleigh number $10^7\leqslant \mbox{Ra}\leqslant 10^8$. For simplicity, we assume the bubbles to be equally sized and having pinned contact lines. We vary the total gas-covered area fraction $0.18 \leqslant S_0 \leqslant 0.62$, the relative bubble height $0.02\leqslant h/H \leqslant 0.05$ (where $H$ is the height of the Rayleigh–Bénard cell), the bubble number $40 \leqslant n \leqslant 144$ and their spatial distribution. In all cases, asymmetric temperature profiles are observed, which we quantitatively explain based on the heat flux conservation at each horizontal section. We further propose the idea of using an equivalent single-phase set-up to mimic the system with attached bubbles. Based on this equivalence, we can calculate the heat transfer. Without introducing any free parameter, the predictions for the Nusselt number, the upper and lower thermal boundary layer thicknesses and the mean centre temperature agree well with the numerical results. Finally, our predictions also work for the cases with much larger $\mbox{Pr}$ (e.g. $400$), which indicates that our results can also be applied to predict the mass transfer in water electrolysis with bubbles attached to the electrode surface or in catalysis.
Dynamics of two-dimensional flow past a rigid flat plate with a trailing closed flexible filament acting as a deformable afterbody are investigated numerically by an immersed boundary-lattice Boltzmann method for the fluid flow and a finite element method for the filament motion. The effects of Reynolds number ($Re$) and length ratio ($Lr$) on the flow patterns and dynamics of the rigid-flexible coupling system are studied. Based on our numerical results, five typical state modes have been identified in $Lr\unicode{x2013}Re$ plane in terms of the filament shape and corresponding dynamics, i.e. static deformation, micro-vibration, multi-frequency flapping, periodic flapping and chaotic flapping modes, respectively. Benefiting from the passive flow control by using the flexible filament as a deformable afterbody, the coupled system may enjoy a significant drag reduction (up to $22\,\%$) compared with bare plate scenarios ($Lr=1$). Maximum drag reduction achieved at $L_{c,{min}} \in [1.8, 2]$ is often accompanied by the onset of the system state transition. The flow characteristic and its relation to the change in hydrodynamic drag are further explored in order to reveal the underlying mechanisms of the counterintuitive dynamical behaviour of the coupled system. The scaling laws for the form drag and the friction drag, which arise from the pressure and viscous effects, respectively, are proposed to estimate the overall drag acting on the system. The results obtained in the present study may shed some light on understanding the dynamical behaviour of rigid-flexible coupling systems.
N-acetylcysteine (NAC) possesses a strong capability to ameliorate high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) in mice, but the underlying mechanism is still unknown. Our study aimed to clarify the involvement of long non-coding RNA (lncRNA) in the beneficial effects of NAC on HFD-induced NAFLD. C57BL/6J mice were fed a normal-fat diet (10 % fat), a HFD (45 % fat) or a HFD plus NAC (2 g/l). After 14-week of intervention, NAC rescued the deleterious alterations induced by HFD, including the changes in body and liver weights, hepatic TAG, plasma alanine aminotransferase, plasma aspartate transaminase and liver histomorphology (haematoxylin and eosin and Oil red O staining). Through whole-transcriptome sequencing, 52 167 (50 758 known and 1409 novel) hepatic lncRNA were detected. Our cross-comparison data revealed the expression of 175 lncRNA was changed by HFD but reversed by NAC. Five of those lncRNA, lncRNA-NONMMUT148902·1 (NO_902·1), lncRNA-XR_001781798·1 (XR_798·1), lncRNA-NONMMUT141720·1 (NO_720·1), lncRNA-XR_869907·1 (XR_907·1), and lncRNA-ENSMUST00000132181 (EN_181), were selected based on an absolute log2 fold change value of greater than 4, P-value < 0·01 and P-adjusted value < 0·01. Further qRT-PCR analysis showed the levels of lncRNA-NO_902·1, lncRNA-XR_798·1, and lncRNA-EN_181 were decreased by HFD but restored by NAC, consistent with the RNA sequencing. Finally, we constructed a ceRNA network containing lncRNA-EN_181, 3 miRNA, and 13 mRNA, which was associated with the NAC-ameliorated NAFLD. Overall, lncRNA-EN_181 might be a potential target in NAC-ameliorated NAFLD. This finding enhanced our understanding of the biological mechanisms underlying the beneficial role of NAC.
The objective of this study was to investigate the effects of different levels of seminal plasma (SP) on boar sperm quality, antioxidant capacity and bacterial concentrations during liquid storage at 17°C. Boar sperm was diluted with Beltsville Thawing Solution (BTS) consisting of 0, 25, 50 and 75% (v/v) of SP. Total motility, progressive motility and dynamic parameters were assessed by the computer assisted sperm analysis (CASA) system. Acrosome and plasma membrane integrity were measured by FITC-PNA/DAPI and SYBR-14/PI staining, respectively. In addition, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, and reactive oxygen species (ROS) levels were detected using commercial assay kits. Bacterial concentrations were assessed by turbidimetric assay. Our results showed that 25% SP markedly improved total motility, progressive motility, sperm dynamic parameters, acrosome integrity compared with 0, 50 and 75% SP (P < 0.05). In addition, 25% SP significantly increased T-AOC but decreased MDA content and ROS levels compared with 0, and 75% SP (P < 0.05). Moreover, 25% SP significantly decreased the bacterial concentrations in extended semen compared with 50% and 75% SP, however, which was higher than with 0% SP (P < 0.05). These results suggest that 25% SP can promote boar sperm quality through enhancing its antioxidant capacity during liquid storage.
The propulsion of a pitching flexible plate in a uniform flow is investigated numerically. The effects of bending stiffness ($K$), pitching amplitude ($A_L$) and frequency ($St$) on the wake patterns, thrust generations and propulsive performances of the fluid–plate system are analysed. Four typical wake patterns, i.e. von Kármán, reversed von Kármán, deflected and chaotic wakes, emerge from various kinematics, and the $St-A_L$ wake maps are given for various $K$. The drag-to-thrust transitions (DTT) and the wake transitions (WT) between the von Kármán and reversed von Kármán wakes are examined. Results indicate that the WT and DTT boundaries can be scaled by the chord-averaged distance of travel, $\mathcal {L}$, which leads to $\mathcal {L}\times St \approx 1$ and $\mathcal {L}\times St \approx 1.2$, respectively. Further, the resonance mechanism for the performance enhancement is revealed and confirmed in a wide range of parameters. The dimensionless average speed of plate, $\mathcal {U^*}\left (=\mathcal {L}\times St\right )$, is adopted merely to characterize the propulsive performances. For the first time, the $\mathcal {U^*}$-based scaling laws for the thrust and power are revealed in pitching rigid and flexible plates for various $A_L$ and $St$. This study may deepen our understanding of biological swimming and flying, and provide a guide for bionic design.
We numerically investigate turbulent Rayleigh–Bénard convection through two immiscible fluid layers, aiming to understand how the layer thickness and fluid properties affect the heat transfer (characterized by the Nusselt number $\mbox {Nu}$) in two-layer systems. Both two- and three-dimensional simulations are performed at fixed global Rayleigh number $\mbox {Ra}=10^8$, Prandtl number $\mbox {Pr}=4.38$ and Weber number $\mbox {We}=5$. We vary the relative thickness of the upper layer between $0.01 \le \alpha \le 0.99$ and the thermal conductivity coefficient ratio of the two liquids between $0.1 \le \lambda _k \le 10$. Two flow regimes are observed. In the first regime at $0.04\le \alpha \le 0.96$, convective flows appear in both layers and $\mbox {Nu}$ is not sensitive to $\alpha$. In the second regime at $\alpha \le 0.02$ or $\alpha \ge 0.98$, convective flow only exists in the thicker layer, while the thinner one is dominated by pure conduction. In this regime, $\mbox {Nu}$ is sensitive to $\alpha$. To predict $\mbox {Nu}$ in the system in which the two layers are separated by a unique interface, we apply the Grossmann–Lohse theory for both individual layers and impose heat flux conservation at the interface. Without introducing any free parameter, the predictions for $\mbox {Nu}$ and for the temperature at the interface agree well with our numerical results and previous experimental data.
We aimed to investigate the relationship between the neutrophil to lymphocyte ratio (NLR) and nutritional parameters in chronic kidney disease (CKD) patients. In this cross-sectional study, 187 non-dialysis CKD patients were enrolled. Daily dietary energy intake (DEI) and daily dietary protein intake (DPI) were assessed by 3-d dietary records. Protein-energy wasting (PEW) was defined as Subjective Global Assessment (SGA) class B and C. Spearman correlation analysis, logistic regression analysis and receiver operating characteristic (ROC) curve analysis were performed. The median NLR was 2·51 (1·83, 3·83). Patients with CKD stage 5 had the highest NLR level. A total of 19·3 % (n 36) of patients suffered from PEW. The NLR was positively correlated with SGA and serum P, and the NLR was negatively correlated with BMI, waist and hip circumference, triceps skinfold thickness, mid-arm muscle circumference, DPI and Hb. Multivariate logistic regression analysis adjusted for DPI, DEI, serum creatinine, blood urea nitrogen, uric acid and Hb showed that a high NLR was an independent risk factor for PEW (OR = 1·393, 95 % CI 1·078, 1·800, P = 0·011). ROC analysis showed that an NLR ≥ 2·62 had the ability to identify PEW among CKD patients, with a sensitivity of 77·8 %, a specificity of 62·3 % and an AUC of 0·71 (95 % CI 0·63, 0·81, P < 0·001). The NLR was closely associated with nutritional status. NLR may be an indicator of PEW in CKD patients.
Extensive magmatism in NE China, eastern Central Asian Orogenic Belt, has produced multi-stage granitic plutons and accompanying W mineralization. The Narenwula complex in the southwestern Great Xing’an Range provides important insights into the petrogenesis, geodynamic processes and relationship with W mineralization. The complex comprises granodiorites, monzogranites and granite porphyry. Mafic microgranular enclaves are common in the granodiorites, and have similar zircon U–Pb ages as their host rocks (258.5–253.9 Ma), whereas the W-bearing granitoids yield emplacement ages of 149.8–148.1 Ma. Permian granodiorites are I-type granites that are enriched in large-ion lithophile elements and light rare earth elements, and depleted in high field strength elements and heavy rare earth elements. Both the mafic microgranular enclaves and granodiorites have nearly identical zircon Hf isotopic compositions. The results suggest that the mafic microgranular enclaves and granodiorites formed by the mixing of mafic and felsic magmas. W-bearing granitoids are highly fractionated A-type granites, enriched in Rb, Th, U and Pb, and depleted in Ba, Sr, P, Ti and Eu. They have higher W concentrations and Rb/Sr ratios, and lower Nb/Ta, Zr/Hf and K/Rb ratios than the W-barren granodiorites. These data and negative ϵHf(t) values (–6.0 to –2.1) suggest that they were derived from the partial melting of ancient lower crust and subsequently underwent extreme fractional crystallization. Based on the regional geology, we propose that the granodiorites were generated in a volcanic arc setting related to the subduction of the Palaeo-Asian Ocean, whereas the W-bearing granitoids and associated deposits formed in a post-orogenic extensional setting controlled by the Mongol–Okhotsk Ocean and Palaeo-Pacific Ocean tectonic regimes.
Membrane transporters including glucose transporters (GLUTs) are involved in cellular energy supplies, cell metabolism and other vital biological activities. They have also been implicated in cancer proliferation and metastasis, thus they represent an important target in combatting cancer. However, membrane transporters are very difficult to study due to their multispan transmembrane properties. The new computational tool, AlphaFold2, offers highly accurate predictions of three-dimensional protein structures. The glutamine, threonine and tyrosine (QTY) code provides a systematic method of rendering hydrophobic sequences into hydrophilic ones. Here, we present computational studies of native integral membrane GLUTs with 12 transmembrane helical segments determined by X-ray crystallography and CryoEM, comparing the AlphaFold2-predicted native structure to their water-soluble QTY variants predicted by AlphaFold2. In the native structures of the transmembrane helices, there are hydrophobic amino acids leucine (L), isoleucine (I), valine (V) and phenylalanine (F). Applying the QTY code, these hydrophobic amino acids are systematically replaced by hydrophilic amino acids, glutamine (Q), threonine (T) and tyrosine (Y) rendering them water-soluble. We present the superposed structures of native GLUTs and their water-soluble QTY variants. The superposed structures show remarkable similar residue mean square distance values between 0.47 and 3.6 Å (most about 1–2 Å) despite >44% transmembrane amino acid differences. We also show the differences of hydrophobicity patches between the native membrane transporters and their QTY variants. We explain the rationale why the membrane protein QTY variants become water-soluble. Our study provides insight into the differences between the hydrophobic helices and hydrophilic helices, and offers confirmation of the QTY method for studying multispan transmembrane proteins and other aggregated proteins through their water-soluble variants.
Indoor ventilation is essential for a healthy and comfortable living environment. A key issue is to discharge anthropogenic air contamination such as CO$_2$ gas or, of potentially more direct consequence, airborne respiratory droplets. Here, by employing direct numerical simulations, we study mechanical displacement ventilation with a wide range of ventilation rates $Q$ from 0.01 to 0.1 m$^3$ s$^{-1}$ person$^{-1}$. For this ventilation scheme, a cool lower zone is established beneath a warm upper zone with interface height $h$, which depends on $Q$. For weak ventilation, we find the scaling relation $h\sim Q^{3/5}$, as suggested by Hunt & Linden (Build. Environ., vol. 34, 1999, pp. 707–720). Also, the CO$_{2}$ concentration decreases with $Q$ within this regime. However, for too strong ventilation, the interface height $h$ becomes insensitive to $Q$, and the ambient averaged CO$_2$ concentration decreases towards the ambient value. At these values of $Q$, the concentrations of pollutants are very low and so further dilution has little effect. We suggest that such scenarios arise when the vertical kinetic energy associated with the ventilation flow is significant compared with the potential energy of the thermal stratification.
The article aims to estimate and forecast the transmissibility of shigellosis and explore the association of meteorological factors with shigellosis. The mathematical model named Susceptible–Exposed–Symptomatic/Asymptomatic–Recovered–Water/Food (SEIARW) was used to explore the feature of shigellosis transmission based on the data of Wuhan City, China, from 2005 to 2017. The study applied effective reproduction number (Reff) to estimate the transmissibility. Daily meteorological data from 2008 to 2017 were used to determine Spearman's correlation with reported new cases and Reff. The SEIARW model fit the data well (χ2 = 0.00046, p > 0.999). The simulation results showed that the reservoir-to-person transmission of the shigellosis route has been interrupted. The Reff would be reduced to a transmission threshold of 1.00 (95% confidence interval (CI) 0.82–1.19) in 2035. Reducing the infectious period to 11.25 days would also decrease the value of Reff to 0.99. There was a significant correlation between new cases of shigellosis and atmospheric pressure, temperature, wind speed and sun hours per day. The correlation coefficients, although statistically significant, were very low (<0.3). In Wuhan, China, the main transmission pattern of shigellosis is person-to-person. Meteorological factors, especially daily atmospheric pressure and temperature, may influence the epidemic of shigellosis.
Adenovirus pneumonia can occur in immunocompetent youths and adults. We conducted a retrospective analysis on five immunocompetent patients (aged ⩾14 years) with adenovirus pneumonia who visited our fever clinic between 1 February 2020 and 29 February 2020. The symptoms at clinical onset were fever, with cough and phlegm production either absent or appearing several days after disease onset. One patient with severe disease exhibited dyspnoea and a rapid development of respiratory failure. A subset of patients had concurrent gastrointestinal symptoms. The results of blood tests revealed normal leukocyte counts, decreased lymphocyte counts and increased C-reactive protein levels. The imaging findings resembled those of bacterial pneumonia, and pleural effusions were present in some cases. Most patients had a good prognosis with symptomatic treatment and supportive care. However, one patient with severe disease and a MuLBSTA score of >12 had a poor prognosis and ultimately died. Immunocompetent youths and adults may develop adenovirus pneumonia, and severe cases are at the risk of death. Since no effective treatments for adenovirus pneumonia are currently known, the early diagnosis and provision of symptomatic treatment and supportive care should be adopted to prevent the development and progression of severe disease.
Anticipatory pleasure deficits are closely correlated with negative symptoms in schizophrenia, and may be found in both clinical and subclinical populations along the psychosis continuum. Prospection, which is an important component of anticipatory pleasure, is impaired in individuals with social anhedonia (SocAnh). In this study, we examined the neural correlates of envisioning positive future events in individuals with SocAnh.
Methods
Forty-nine individuals with SocAnh and 33 matched controls were recruited to undergo functional MRI scanning, during which they were instructed to simulate positive or neutral future episodes according to cue words. Two stages of prospection were distinguished: construction and elaboration.
Results
Reduced activation at the caudate and the precuneus when prospecting positive (v. neutral) future events was observed in individuals with SocAnh. Furthermore, compared with controls, increased functional connectivity between the caudate and the inferior occipital gyrus during positive (v. neutral) prospection was found in individuals with SocAnh. Both groups exhibited a similar pattern of brain activation for the construction v. elaboration contrast, regardless of the emotional context.
Conclusions
Our results provide further evidence on the neural mechanism of anticipatory pleasure deficits in subclinical individuals with SocAnh and suggest that altered cortico-striatal circuit may play a role in anticipatory pleasure deficits in these individuals.
Nicotine 3,5-dihydroxybenzoate dihydrate is a nicotine salt and can be used as compositions in tobacco products. X-ray powder diffraction data, unit-cell parameters, and space group for nicotine 3,5-dihydroxybenzoate, C10H15N2⋅C7H5O4⋅2H2O, are reported [a = 8.424(1) Å, b = 13.179(8) Å, c = 8.591(1) Å, α = 90°, β = 102.073(8)°, γ = 90°, unit-cell volume V = 932.765(3) Å3, Z = 2, ρcal = 1.256 g⋅cm−3, and space group P21] at room temperature. All measured lines were indexed and are consistent with the P21 space group.
Hypertension represents one of the most common pre-existing conditions and comorbidities in Coronavirus disease 2019 (COVID-19) patients. To explore whether hypertension serves as a risk factor for disease severity, a multi-centre, retrospective study was conducted in COVID-19 patients. A total of 498 consecutively hospitalised patients with lab-confirmed COVID-19 in China were enrolled in this cohort. Using logistic regression, we assessed the association between hypertension and the likelihood of severe illness with adjustment for confounders. We observed that more than 16% of the enrolled patients exhibited pre-existing hypertension on admission. More severe COVID-19 cases occurred in individuals with hypertension than those without hypertension (21% vs. 10%, P = 0.007). Hypertension associated with the increased risk of severe illness, which was not modified by other demographic factors, such as age, sex, hospital geological location and blood pressure levels on admission. More attention and treatment should be offered to patients with underlying hypertension, who usually are older, have more comorbidities and more susceptible to cardiac complications.
Cost-effective sampling design is a problem of major concern in some experiments especially when the measurement of the characteristic of interest is costly or painful or time-consuming. In this article, we investigate ratio-type estimators of the population mean of the study variable, involving either the first or the third quartile of the auxiliary variable, using ranked set sampling (RSS) and extreme ranked set sampling (ERSS) schemes. The properties of the estimators are obtained. The estimators in RSS and ERSS are compared to their counterparts in simple random sampling (SRS) for normal data. The numerical results show that the estimators in RSS and ERSS are significantly more efficient than their counterparts in SRS.
This study aimed at estimating the transmissibility of hepatitis C. The data for hepatitis C cases were collected in six districts in Xiamen City, China from 2004 to 2018. A population-mixed susceptible-infectious-chronic-recovered (SICR) model was used to fit the data and the parameters of the model were calculated. The basic reproduction number (R0) and the number of newly transmitted cases by a primary case per month (MNI) were adopted to quantitatively assess the transmissibility of hepatitis C virus (HCV). Eleven curve estimation models were employed to predict the trends of R0 and MNI in the city. The SICR model fits the reported HCV data well (P < 0.01). The median R0 of each district in Xiamen is 0.4059. R0 follows the cubic model curve, the compound curve and the power function curve. The median MNI of each district in Xiamen is 0.0020. MNI follows the cubic model curve, the compound curve and the power function curve. The transmissibility of HCV follows a decreasing trend, which reveals that under the current policy for prevention and control, there would be a high feasibility to eliminate the transmission of HCV in the city.