Mobile phone dependence, social support and impulsivity in Chinese university students

This study examined the frequency of mobile phone dependence in Chinese university students and explored its association with social support and impulsivity. Altogether, 909 university students were consecutively recruited from a large university in China. Mobile phone use, mobile phone dependence, impulsivity, and social support were measured with standardized instruments. The frequency of possible mobile phone use and mobile phone dependence was 78.3% and 7.4%, respectively. Multinomial logistic regression analyses revealed that compared with no mobile phone dependence, possible mobile phone dependence was significantly associated with being male (p = 0.04, OR = 0.7, 95% CI: 0.4–0.98), excessive mobile phone use (p \u3c 0.001, OR = 1.2, 95% CI: 1.09–1.2), and impulsivity (p \u3c 0.001, OR = 1.05, 95% CI: 1.03–1.06), while mobile phone dependence was associated with length of weekly phone use (p = 0.01, OR = 2.5, 95% CI: 1.2–5.0), excessive mobile phone use (p \u3c 0.001, OR = 1.3, 95% CI: 1.2–1.4), and impulsivity (p \u3c 0.001, OR = 1.08, 95% CI: 1.05–1.1). The frequency of possible mobile phone dependence and mobile phone dependence was high in this sample of Chinese university students. A significant positive association with impulsivity was found, but not with social support

First detection of Cryptosporidium spp. in red-bellied tree squirrels (Callosciurus erythraeus) in China

Cryptosporidium spp. are opportunistic pathogens that cause diarrhea in a variety of animal hosts. Although they have been reported in many animals, no information has been published on the occurrence of Cryptosporidium spp. in red-bellied tree squirrels (Callosciurus erythraeus). A total of 287 fecal specimens were collected from Sichuan province in China; the prevalence of Cryptosporidium spp., measured by nested-PCR amplification of the partial small-subunit (SSU) rRNA gene, was 1.4% (4/287). Three different Cryptosporidium species or genotypes were identified: Cryptosporidium parvum (n = 1), Cryptosporidium wrairi (n = 1), and Cryptosporidium rat genotype II (n = 2). The present study is the first report of Cryptosporidium infection in red-bellied tree squirrels in China. Although there is a relatively low occurrence of Cryptosporidium, the presence of C. parvum and C. wrairi, which were previously reported in humans, indicates that red-bellied tree squirrels may be a source of zoonotic cryptosporidiosis in China

Sparse system identification using orthogonal rational functions

We consider the problem of reconstructing a real sparse coefficient θ of a transfer function under the orthogonal rational functions from a limit number of linear measurements. Given m randomly selected samples of Φθ, where Φ is a sample matrix constructed by orthogonal rational functions at samples in the unit circle, we show that ℓ1 minimization can recover the coefficient θ from the real part model or the imaginary part model for the real and imaginary part of Φ have the similar structure of the orthogonal matrix

Design of synthesis filter banks for the structural similarity index

The optimal synthesis filter bank (FB) is designed for a given analysis FB by using the structural similarity (SSIM) criteria. Under the assumption that the source signal is a wide sense stationary (WSS) process with known power spectral density (PSD), that the noise is Gaussian white, and that the filter length is equal to the decimation number, the optimization problem is formulated. The closed-form solution is obtained when the mean of the source is zero. It is shown that the optimal FB designed by SSIM criteria and the one by mean square error (MSE) criteria differs only from a scalar factor. Finally, numerical example is given to compare the performance of different synthesis FBs

Optimal design of oversampled filter banks with lattice structure

For an oversampled linear phase (LP) perfect reconstruction filter banks with lattice structure, the synthesis FB is not unique. However, existing methods to choose a synthesis FB for “optimal” noise reduction may destroy the linear phase and lattice structure property. This paper studies the noise reduction design problem for oversampled filter banks (FBs) preserving lattice structure. Both the optimal design and worst case design are considered, where the former caters for the noise with known power spectral density (PSD), and the latter for the noise with unknown PSD. Explicit formula for the former and LMI-based algorithms for the latter are provided

Optimal two-sided diagonal scaling for filter bank frames

Two-sided diagonal scaling for transfer matrices is formulated. An efficient algorithm is proposed to compute globally optimal solutions using the iterated bi-section and linear matrix inequality (LMI) solver. It is shown that the two-sided scaling of filter bank (FB) frames can be implemented by the adjustment of channel gains and the periodic precoding of source signal, and that the frame-bound-ratio of FB frames can be effectively improved by such scaling. Explicit formulas are established for both uniform and nonuniform FB frames, including detail formulas for discrete Weyl-Heisenberg frames and tree-structured FBs (discrete wavelets). Different examples show the effectiveness of the obtained results