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We consider a model with both a parametric global trend and a nonparametric local trend. This model may be of interest in a number of applications in economics, finance, ecology, and geology. We first propose two hypothesis tests to detect whether two nested special cases are appropriate. For the case where both null hypotheses are rejected, we propose an estimation method to capture certain aspects of the time trend. We establish consistency and some distribution theory in the presence of a large sample. Moreover, we examine the proposed hypothesis tests and estimation methods through both simulated and real data examples. Finally, we discuss some potential extensions and issues when modelling time effects.
In this paper we prove some one-level density results for the low-lying zeros of families of quadratic and quartic Hecke
-functions of the Gaussian field. As corollaries, we deduce that at least 94.27% and 5%, respectively, of the members of the quadratic family and the quartic family do not vanish at the central point.
To obtain rich information about the cognitive diagnosis of borderline personality disorder (BPD), this study attempted to retrofit a traditional borderline personality questionnaire so that the improved assessment (called CDA-BPD) could provide more diagnostic information. The retrofitting processes included the following steps: (1) applied an cognitive diagnosis model to analyze the psychometric characteristics of the traditional questionnaire; (2) under the guidance of cognitive diagnosis assessment (CDA), high-quality items were chosen to develop the CDA-BPD and tested on 1,097 subjects; (3) the quality of the CDA-BPD was evaluated; (4) the structure of the CDA-BPD was analyzed. Results indicated that: (1) the CDA-BPD had acceptable reliability and validity; (2) the CDA-BPD had sensitivity of 0.985 and specificity of 0.853 with area under curve (AUC) = 0.956; (3) the two structural factors of the traditional questionnaire were confirmed in the CDA-BPD; χ2 was 83.01 with df = 26, p < .0001, comparative fit index (CFI) = 0.97, root mean square error of approximation (RMSEA) = 0.045. It was concluded that the practice of retrofitting a traditional borderline personality assessment for cognitive diagnostic purpose was feasible. Most importantly, under the cognitive diagnosis model framework, CDA-BPD could simultaneously provide general-level information and the detailed symptom criteria-level information about the posterior probability of satisfying each symptom criterion in the Diagnostic and Statistical Manual of Mental Disorders (5th edition; DSM-5; American Psychiatric Association, 2013) for each individual, which gave further insight into tailoring individual-specific treatments for borderline personality disorder.
A novel online antenna array calibration method is presented in this paper for estimating direction-of-arrival (DOA) in the case of uncorrelated and coherent signals with unknown gain-phase errors. Conventional calibration methods mainly consider incoherent signals for uniform linear arrays with gain-phase errors. The proposed method has better performance not only for uncorrelated signals but also for coherent signals. First, an on-grid sparse technique based on the covariance fitting criteria is reformulated aiming at gain-phase errors to obtain DOA and the corresponding source power, which is robust to coherent sources. Second, the gain-phase errors are estimated in the case of uncorrelated and coherent signals via introducing an exchange matrix as the pre-processing of a covariance matrix and then decomposing the eigenvalues of the covariance matrix. Those parameters estimate values converge to the real values by an alternate iteration process. The proposed method does not require the presence of calibration sources and previous calibration information unlike offline ways. Simulation results verify the effectiveness of the proposed method which outperforms the traditional approaches.
Liquid films can be entrained when the dewetting velocity attains a threshold, and this dynamical wetting transition has been well studied in the situation of plane substrates. We investigate the forced dewetting in a capillary tube using diffuse-interface simulations and lubrication analysis, focusing on the onset of wetting transition and subsequent interface evolution. Results show that the meniscus remains stable when the displacing rate is below a threshold, beyond which film entrainment occurs and eventually leads to the formation of Taylor bubbles separated by liquid slugs, as has also been observed in the recent experiments of Zhao et al. (Phys. Rev. Lett., vol. 120, 2018, 084501). We derive an analytical solution of the critical capillary number, and demonstrate that the wetting transition is accompanied by a vanishing apparent contact angle and an abrupt drop of the contact-line velocity. Both the bubble and slug lengths are found to depend on the capillary number and the wettability of the wall. A theoretical formula for the bubble length is also proposed and compares favourably with numerical and experimental results.
Gut microbes, especially those in the large intestine, are actively involved in nutrient metabolism; however, their impact on host nitrogen (N) metabolism remains largely unknown. This study was designed to investigate the effects of feeding a cocktail of antibiotics (AGM) (ampicillin, gentamycin and metronidazole) on intestinal microbiota, N utilization efficiency, and amino acid (AA) digestibility in cannulated pigs, with the aim of exploring the impact of gut microbiota on host N metabolism. In total, 16 piglets were surgically fitted with a simple distal ileal T-cannula and a jugular venous catheter. The pigs were fed a basal diet without antibiotics (control; CON) or with antibiotics (antibiotic; ANTI), for 2 weeks. The results showed that feeding AGM did not affect weight gain or digestive enzyme activity. The antibiotics increased the concentration of urea N (P<0.05). However, they reduced N utilization, and the total tract apparent digestibility of isoleucine, methionine, valine, tyrosine and total AA (P<0.05). Furthermore, the antibiotics increased the terminal ileum apparent digestibility of CP, phenylalanine, valine, alanine, tyrosine and total AA (P<0.05). AGM markedly altered the composition of the microbiota in the ileum and feces, with a reduction in populations of Bifidobacterium, Lactobacillus and Ruminococcus, and an increase in the abundance of Escherichia coli (P<0.05). The antibiotics also significantly increased the concentration of cadaverine and ammonia, both in ileal digesta and feces (P<0.05), suggesting a marked impact on N metabolism in the intestine. The analyses indicated that the alteration of gut microbiota was correlated with the apparent digestibility of CP and AA in the intestine. These findings suggest that the AGM-induced alteration of gut microbiota may contribute to the change in intestinal N metabolism, and consequently, N excretion from the body. These results also suggest that antibiotics could have a significant effect on host N metabolism. The present study contributes to our understanding of the effects of antibiotics and provides a rational scientific basis for diet formulation during AGM use.
Invasive smooth cordgrass (Spartina alterniflora Loisel) eradication is important for the health of many coastal ecosystems. An integrated regime of continuous submergence after clear mowing, with three interval levels between mowing and submergence (5, 10, and 15 d) and three submergence depths (20, 30, and 50 cm), was implemented in cofferdams enclosing invader populations along a Chinese coast. In July of the following year, after the roots of mowed S. alterniflora had been submerged for 12 mo, some ramets grew under the regime with an interval of 15 d and the regime with a submergence depth of 20 cm, but no ramets occurred under the regimes with submergence depths of 30 or 50 cm and intervals of 5 or 10 d. Four crab species were documented: Helice tridens tientsinensis Rathbun, Sesarma dehaani H. Milne-Edwards, Ocypode stimpsoni Ortmann, and Chiromantes haematocheir de Haan. Biomass and abundance values of crab species in the cofferdams were similar to those in the mudflats but different from those in smooth cordgrass populations. Thus, the treatment of submergence after mowing, which was implemented in the cofferdams, can control S. alterniflora and provide a mudflat-like habitat that promotes crab recovery if this treatment uses the proper combination of submergence depth and interval between mowing and submergence.
When a contact line moves with a sufficiently large speed, liquid or gas films can be entrained on a solid depending on the direction of contact-line movement. In this work, the contact-line dynamics in the situation of a generic two-fluid system is investigated. We demonstrate that the hydrodynamics of a contact line, no matter whether advancing or receding, can formally reduce to that of a receding one with small interfacial slopes. Since the latter can be well treated under the classical lubrication approximation, this analogy allows us to derive an asymptotic solution of the interfacial profiles for arbitrary values of contact angle and viscosity ratio. For the dip-coating geometry, we obtain, with no adjustable parameters, an analytical formula for the critical speed of wetting transition, which in particular predicts the onset of both liquid and gas entrainment. Moreover, the present analysis also builds a novel connection between the Cox–Voinov law and classical lubrication theory for moving contact lines.
In this paper, we investigate the ratchet mechanism of drops climbing a vibrated oblique plate based on three-dimensional direct numerical simulations, which for the first time reproduce the existing experiment (Brunet et al., Phys. Rev. Lett., vol. 99, 2007, 144501). With the help of numerical simulations, we identify an interesting and important wetting behaviour of the climbing drop; that is, the breaking of symmetry due to the inclination of the plate with respect to the acceleration leads to a hysteresis of the wetted area in one period of harmonic vibration. In particular, the average wetted area in the downhill stage is larger than that in the uphill stage, which is found to be responsible for the uphill net motion of the drop. A new hydrodynamic model is proposed to interpret the ratchet mechanism, taking account of the effects of the acceleration and contact angle hysteresis. The predictions of the theoretical analysis are in good agreement with the numerical results.
We study the complex dynamics of a two-dimensional suspension comprising non-motile active particles confined in an annulus. A coarse-grained liquid crystal model is employed to describe the nematic structure evolution, and is hydrodynamically coupled with the Stokes equation to solve for the induced active flows in the annulus. For dilute suspensions, coherent structures are captured by varying the particle activity and gap width, including unidirectional circulations, travelling waves and chaotic flows. For concentrated suspensions, the internal collective dynamics features motile disclination defects and flows at finite gap widths. In particular, we observe an intriguing quasi-steady-state at certain gap widths during which
-order defects oscillate around equilibrium positions accompanying travelling-wave flows that switch circulating directions periodically. We perform linear stability analyses to reveal the underlying physical mechanisms of pattern formation during a concatenation of instabilities.
In this paper, drop impact onto a sphere is numerically investigated at moderate Reynolds and Weber numbers. It is naturally expected that the aspect ratio of the sphere to the drop,
, would make a big difference to drop spreading and retraction on the sphere, compared with drop impact onto a flat substrate. To quantitatively assess the effect of
, a diffuse-interface immersed-boundary method is adopted after being validated against experiments. With the help of numerical simulations, we identify the key regimes in the spreading and retraction, analyse the results by scaling laws, and quantitatively evaluate the effect of
on the impact dynamics. We find that the thickness of the liquid film spreading on the sphere can be well approximated by
represents the film thickness of drop impact on a flat substrate. At the early stage of spreading, the temporal variation of the wetted area is independent of
when the time is rescaled by the thickness of the liquid film. Drops are observed to retract on the sphere at a roughly constant speed, and the predictions of theoretical analysis are in good agreement with numerical results.
To describe our finding of increased ossification of the modiolus in paediatric patients with auditory neuropathy who met criteria for cochlear implantation.
A retrospective case series with a comparison group at a tertiary referral centre is described. Seven paediatric patients with auditory neuropathy who met criteria for and underwent cochlear implantation were identified. Fifteen paediatric implantees with bilateral profound sensorineural hearing loss were included as the comparison group. All patients underwent pre-operative computed tomography. Attenuation at the modiolus was measured in all subjects by a neuroradiologist blinded to clinical information.
Attenuation values in the modiolus in the auditory neuropathy patients (mean ± standard deviation = 796.2 ± 53.0 HU) was statistically significantly higher than in the comparison sensorineural hearing loss patients (267.1 ± 45.6 HU; p < 0.05, t-test).
Patients with auditory neuropathy who meet criteria for cochlear implantation demonstrate significantly higher modiolar attenuation on computed tomography imaging, consistent with increased ossification at the modiolus.
To determine the prevalence of high weight at different characteristics, understand the perceptions and behaviours towards high body weight, and determine potential influencing factors of body weight misperception among high-weight adults in Jilin Province.
A cross-sectional survey with complex sampling design was conducted. We described the prevalence and perception of high body weight.
Northeast China in 2012.
Adults (n 20 552) aged 18–79 years.
Of overweight individuals, 37·4 % considered themselves as ‘normal weight’, 4·8 % reported themselves as being ‘very thin’ and only 53·1 % were aware of their own weight being ‘overweight’. About 1·8 % of both male and female obese individuals perceived themselves as ‘very thin’. Only 29·1 % of obese people thought of themselves as ‘too fat’. Nearly 30·0 % of centrally obese men and women perceived that their waist circumference was about right and they were of ‘normal weight’; 5·7 % of the centrally obese even perceived themselves as being ‘very thin’. Only 51·8 and 12·5 % of centrally obese individuals reported themselves to be ‘overweight’ or ‘too fat’. Body weight misperception was more common in rural residents (OR; 95 % CI: 1·340; 1·191, 1·509). The prevalence of body weight misperception increased with age (middle age: 1·826; 1·605, 2·078; old people: 3·101; 2·648, 3·632) and declined with increased education level (junior middle school: 0·628; 0·545, 0·723; senior middle school: 0·498; 0·426, 0·583; undergraduate and above: 0·395; 0·320, 0·487).
Body weight misperception was common among adults from Jilin Province.
With increasing output of petroleum coke, the value-added exploitation of petroleum coke has become a tough problem. Preparing porous carbons is a traditional way to the value-added exploitation of petroleum coke. Here, we used a facile and efficient hard-templating strategy to synthesize mesoporous carbon with high surface area from petroleum coke. N2 adsorption analyses show that the BET specific area and pore volume of the carbons can reach up to 864 m2/g and 1.37 cm3/g, respectively. To utilize the abundant mesopores of the carbons, anthraquinone-modified mesoporous carbon was tested as an electrode material for supercapacitor applications. Electrochemical measurements demonstrated that the specific capacitance reached up to 366 F/g at the current density of 1 A/g, indicating a promising prospect of using this carbon in electrochemical energy-storage field. More importantly, the strategy used in this work can be easily modified to prepare other nano-carbon materials from petroleum coke.
In this study, a system of triple liquid phases was developed using Li2CO3, Na2CO3, and K2CO3 to improve the densification of the akermanite scaffolds fabricated by selective laser sintering (SLS). The system formed a ternary liquid phase (Li2CO3–Na2CO3–K2CO3) at 399 °C, a binary liquid phase (Na2CO3–K2CO3) at 695 °C, and a unitary liquid phase (K2CO3) at 891 °C during sintering process. The effects of the liquid phases on the sinterability and mechanical properties of the scaffolds were investigated. The fracture toughness and compressive strength is increased by 43 and 152% with liquid phases increasing from 0 to 4 wt%, respectively. This was explained that liquid phases enhanced densification via improving diffusion kinetics and inducing particle rearrangement. In addition, the scaffolds maintained favorable hydroxyapatite (HA) formation ability and cell proliferation ability, which was proved by simulated body fluid (SBF) test and microculture tetrazolium test (MTT), respectively.
A review of recently published temporal data from Shuidonggou Locality 1 indicates that a 40–43 cal ka date for the inception of Initial Upper Paleolithic (IUP) blade-oriented technologies in East Asia is warranted. Comparison of the dates from Shuidonggou to other Asian IUP dates in Korea, Siberia, and Mongolia supports this assertion, indicating that the initial appearance of the IUP in East Asia generally corresponds in time to the fluorescence of the IUP in eastern Europe and western Asia. This conclusion preliminarily suggests that either a version of the IUP originated independently in East Asia just prior to 40 cal ka, or more likely, that an early, initial diffusion of the IUP into East Asia occurred ∼41 cal ka, a hypothesis consistent with current estimates for the evolution or arrival of modern humans in the region.