61 research outputs found
Nonparametric Independence Screening in Sparse Ultra-High Dimensional Varying Coefficient Models
The varying-coefficient model is an important nonparametric statistical model
that allows us to examine how the effects of covariates vary with exposure
variables. When the number of covariates is big, the issue of variable
selection arrives. In this paper, we propose and investigate marginal
nonparametric screening methods to screen variables in ultra-high dimensional
sparse varying-coefficient models. The proposed nonparametric independence
screening (NIS) selects variables by ranking a measure of the nonparametric
marginal contributions of each covariate given the exposure variable. The sure
independent screening property is established under some mild technical
conditions when the dimensionality is of nonpolynomial order, and the
dimensionality reduction of NIS is quantified. To enhance practical utility and
the finite sample performance, two data-driven iterative NIS methods are
proposed for selecting thresholding parameters and variables: conditional
permutation and greedy methods, resulting in Conditional-INIS and Greedy-INIS.
The effectiveness and flexibility of the proposed methods are further
illustrated by simulation studies and real data applications
Delayed Effect of Anisaldehyde on Feeding Behavior and Reproduction of Adult Aedes albopictus (Diptera: Culicidae) 1
ABSTRACT Anisaldehyde may be useful as a spatial repellent against Aedes albopictus, and it could play a major role in new repellent technology for mosquito management. This study characterized the delayed effects of anisaldehyde on Ae. albopictus adult host-seeking behavior, feeding behavior, and reproduction. Anisaldehyde was applied as a fumigant (0.25 mg/cm 3 ) during different developmental stages of the mosquito (larvae from 1 st instar to pupation, larvae from 1 st instar to adult emergence, pupae, and two-day-old adults). Except when treated as pupae, the resulting adult females (at 5 days of age) exhibited significantly lower host-seeking capability and lower repeated-feeding rates than untreated females. Anisaldehyde treatments also significantly reduced the number of eggs and hatchability, and this chemical prolonged the gonotrophic cycle and egg development. These results showed that anisaldehyde acted as a spatial repellent, where it not only reduced hostseeking capability, but also greatly reduced vectoring capacity and reproduction potential, which is significant for mosquito control and disease prevention
Effect of direct current electric field intensity and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment
The effect of direct current (DC) electric field and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment were investigated using electrochemical measurements. The results show that the limiting diffusion current density (ilim) decreases with increasing the thin electrolyte layers (TELs) thickness but it increases with increasing the DC electric field intensity. The potential shifts negatively with the DC electric field. It is found that the DC electric field enables OH− ions to quickly migrate from the solution/electrode interface to the electrolyte layer. All these features promote the cathodic reduction process thereby enhancing the metal corrosion rate
Numerical Simulations of the Lunar Penetrating Radar and Investigations of the Geological Structures of the Lunar Regolith Layer at the Chang’E 3 Landing Site
Efficacy, Stability, and Biosafety of Sifuvirtide Gel as a Microbicide Candidate against HIV-1
Sifuvirtide is a proven effective HIV-1 entry inhibitor and its safety profile has been established for systemic administration. The present study evaluated the potential of sifuvirtide formulated in a universal gel for topical use as a microbicide candidate for preventing sexual transmission of HIV. Our data showed that sifuvirtide formulated in HEC gel is effective against HIV-1 B, C subtypes, CRF07_BC and CRF01_AE, the latter two recombinants represents the most prevalent strains in China. In addition, we demonstrated that sifuvirtide in gel is stable for at least 8 weeks even at 40°C, and did not cause the disruption of integrity of mucosal epithelial surface, or the up-regulation of inflammatory cytokines both in vitro or in vivo. These results suggest that sifuvirtide gel is an effective, safe and stable product, and should be further tested as a vaginal or rectal microbicide in pre-clinical model or clinical trial for preventing HIV sexual transmission
Analogue simulation and analysis of non-circular gear reentry error
The studies on non-circular gear cutting and using errors were generally based on theory of cylindrical gear errors, and the similarities and differences between cylindrical gear and non-circular gear were combined to study the change rule of non-circular gear contacting line and obtained corresponding conclusions. In this paper, from a different perspective, by starting from the non-circular gear engagement principle, on the basis of analyzing the concrete geometric error conditions, new type tooth profile algorithm routine is reasonably modified, and needed non-circular gear tooth profile error contrast figure is obtained. Furthermore, theoretical derivation is carried out by incorporating analytical method and contacting line incremental method, validity of computer simulation is verified, and the characterization of the tangential error characteristic code is obtained, Summed up the error sources for error genetic which possess enormous significance to direct practice generation
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