Search

BackgroundLong-term alcohol drinking is associated with numerous health complications including susceptibility to infection, cancer, and organ damage. However, due to the complex nature of human drinking behavior, it has been challenging to identify reliable biomarkers of alcohol drinking behavior prior to signs of overt organ damage. Recently, extracellular vesicle-bound microRNAs (EV-miRNAs) have been found to be consistent biomarkers of conditions that include cancer and liver disease.MethodsIn this study, we profiled the plasma EV-miRNA content by miRNA-Seq from 80 nonhuman primates after 12 months of voluntary alcohol drinking.ResultsWe identified a list of up- and downregulated EV-miRNA candidate biomarkers of heavy drinking and those positively correlated with ethanol dose. We overexpressed these candidate miRNAs in control primary peripheral immune cells to assess their potential functional mechanisms. We found that overexpression of miR-155, miR-154, miR-34c, miR-450a, and miR-204 led to increased production of the inflammatory cytokines TNFα or IL-6 in peripheral blood mononuclear cells after stimulation.ConclusionThis exploratory study identified several EV-miRNAs that could serve as biomarkers of long-term alcohol drinking and provide a mechanism to explain alcohol-induced peripheral inflammation.

We propose a Bayesian nonparametric clustering approach to study the spatial heterogeneity effect for functional data observed at spatially correlated locations. We consider a geographically weighted Chinese restaurant process equipped with a conditional autoregressive prior to capture fully the spatial correlation of function curves. To sample efficiently from our model, we customize a prior called Quadratic Gamma, which ensures conjugacy. We design a Markov chain Monte Carlo algorithm to infer simultaneously the posterior distributions of the number of groups and the grouping configurations. The superior numerical performance of the proposed method over competing methods is demonstrated using simulated examples and a U.S. annual precipitation study. [ABSTRACT FROM AUTHOR]

This study reveals the blockage effects on vortex shedding, the lock-in mechanism of a forced oscillating cylinder, and the coupling effects of blockage and oscillation. The wind tunnel experiments and large eddy simulations were conducted at a Reynolds number of 2000, encompassing a range of blockage ratios from 0.15 to 0.5. The cylinder is subjected to forced harmonic oscillations in a direction perpendicular to the incoming flow to investigate the frequency lock-in mechanism. The research findings demonstrate that both blockage and forced vibration significantly influence the dynamics of vortex shedding by altering the development of the shear layer instability (SLI). For a fixed cylinder, high blockage effectively suppresses the growth of transverse disturbances, promoting a stable maintenance of the shear layer (SL). In high blockage, the flow deceleration induces the separation of the boundary layer from the sidewalls and the subsequent constriction of the mainstream toward the channel centerline, consequently leading to an increase in the Strouhal number. For the case of a fixed blockage ratio, forced vibration alters the flow supplement in the near-SL region. During the unlocked phase, a significant occurrence of backflow is observed near the SL, which promotes the development of SLI. However, proper vibration induces the transverse flow supplement in the near-SL region, which balance the amount carried away by mainstream, thereby suppressing the backflow. The coupling effects of blockage and vibration are evident in the shift of the lock-in region and the triggering of hysteresis, both of which are explained by the proposed mechanisms of blockage and lock-in. [ABSTRACT FROM AUTHOR]

We propose a novel nonparametric Bayesian item response theory model that estimates clusters at the question level, while simultaneously allowing for heterogeneity at the examinee level under each question cluster, characterized by a mixture of binomial distributions. The main contribution of this work is threefold. First, we present our new model and demonstrate that it is identifiable under a set of conditions. Second, we show that our model can correctly identify question‐level clusters asymptotically, and the parameters of interest that measure the proficiency of examinees in solving certain questions can be estimated at a n rate (up to a log term). Third, we present a tractable sampling algorithm to obtain valid posterior samples from our proposed model. Compared to the existing methods, our model manages to reveal the multi‐dimensionality of the examinees' proficiency level in handling different types of questions parsimoniously by imposing a nested clustering structure. The proposed model is evaluated via a series of simulations as well as apply it to an English proficiency assessment data set. This data analysis example nicely illustrates how our model can be used by test makers to distinguish different types of students and aid in the design of future tests. [ABSTRACT FROM AUTHOR]

DPS (distributed propulsion system) utilizing BLI (boundary-layer ingestion) has shown great potential for reducing the power consumption of sustainable AAM (advanced air mobility), such as BWB (blended-wing body) aircraft. However, the ingesting boundary layer makes it easier for flow separation to occur within the S-shaped duct, and the consequent distortion due to flow separation can dramatically reduce the aerodynamic performance of the fan, which offsets the power-saving benefit of BLI. By analyzing the source of power saving and power loss of BLI, this paper presents the LDPS (layered distributed propulsion system) concept, in which the freestream flow and boundary-layer flow are ingested separately to improve the power-saving benefit of BLI. In order to preliminarily verify the feasibility of LDPS, an existing DPS is modified. The design parameters and the system performances of LDPS are studied using a 1D engine model. The results show that there is an optimal ratio of the FPR (fan pressure ratio) for the FSE (freestream engine) to the BLE (boundary-layer engine) that maximizes the PSC (power-saving coefficient) of LDPS. This optimal ratio of FPR for the two fans can be obtained when the exit velocities of FSE and BLE are the same. Under the optimal ratio of FPR for the two fans, the PSC of LDPS is improved by 5.83% compared to conventional DPS. [ABSTRACT FROM AUTHOR]

A new non-intrusive reduced-order modeling method based on space-time parameter decoupling for parametrized time-dependent problems is proposed. This method requires the preparation of a database comprising high-fidelity solutions. The spatial bases are extracted from the database through first-level proper orthogonal decomposition (POD). The algebraic relationship between the time trajectory/parameter positions and the projection coefficient is described by the linear superposition of the second-level POD bases (temporal bases) and the second-level projection coefficients (parameter-dependent coefficients). This decomposition strategy decouples the space-time parameter effects, providing a stable foundation for fast predictions of parametrized time-dependent problems. The mappings between the parameter locations and the parameter-dependent coefficients are approximated as Gaussian process regression (GPR) models. The accuracy and efficiency of the PPOD-ROM are demonstrated through two numerical examples: flows past a cylinder and turbine flows with a clocking effect. [ABSTRACT FROM AUTHOR]

s t r i n g U t i l s. c o n v e r t A b s t r a c t M a t h H t m l (formulaUtilTools.convertMathHtml( s t r i n g U t i l s. c o n v e r t M m l (!article.abstractinfoEn))) The mean value problems of exponential sums play a very important role in the research of analytic number theory, and many famous number theory problems are closely related to them. The main purpose of this paper is using some elementary methods and the number of the solutions of the congruence equations to study the calculating problem of some fourth power means of two-term exponential sums, and give exact calculating formulae and asymptotic formula for them. [ABSTRACT FROM AUTHOR]