Examining user acceptance of SMS: An empirical study in China and Hong Kong

Short message service (SMS) has become an integral part of people\u27s lives. It is one of the most popular services for mobile communications. This paper examines the determinants of user intention to use SMS. We proposed and empirically tested a model with seven main determinants of user acceptance and two key moderators (i.e., gender and region). Our data were collected via a survey of 471 mobile phone users in China and Hong Kong. The results showed that perceived usefulness, perceived ease of use, perceived enjoyment, and perceived critical mass were the key direct determinants of user acceptance of SMS. Visibility, subjective norm, and perceived cost-effectiveness were found to have indirect influences on user acceptance via the key determinants. In addition, the results showed that gender and region each played an important role in affecting user acceptance, and the significant determinants vary across regions. We discuss implications related to mobile communication services

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye

<p>Abstract</p> <p>Background</p> <p>Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the <it>Drosophila </it>eye. Here we report the isolation of a new loss-of-function <it>ras </it>allele, <it>ras</it>^<it>KP</it>, which causes excessive apoptosis in the <it>Drosophila </it>eye.</p> <p>Results</p> <p>This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress <it>ras</it>^<it>KP</it>-induced apoptosis, whereas the removal of <it>hid </it>only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the <it>ras</it>^{<it>KP </it>}cell death. In addition, we find a strong correlation between <it>ras</it>^<it>KP</it>-induced apoptosis in the eye disc and the activation of JNK signalling.</p> <p>Conclusion</p> <p>In the <it>Drosophila </it>eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.</p

Investigation of the antidepressant effects of Shu-Gan-Jie- Yu granule and its mechanism of action

Purpose: To study the antidepressant effects of Shu-Gan-Jie-Yu granule (SJG) and its possible mechanisms in mice.Methods: The anti-depressive effects of SJG were evaluated by three techniques, viz, forced swimming test (FST), tail suspension test (TST) and open field test (OFT). The levels of the neurotransmitters norepinephrine (NE), DA, and 5-HT in the brains of depressive mice were determined using commercially available kits. In addition, the effects of SJG on the BDNF expression in the mice brain were determined by western blot.Results: Administration of SJG significantly reduced the duration time of immobility in the experiments of FST and TST. In addition, relative to the control mice, SJG (800 mg/kg) administration significantly affected the mobility performance (p &lt; 0.05) of mice. The levels of the three&nbsp; neurotransmitters (DA, NE and 5-HT) and BDNF in the brains of depressive mice were increased by treatment with SJG at the doses of 200, 400 and 800 mg/kg (p &lt; 0.05). The results suggested that SJG exerted a significant antidepressant effect, which could be attributed to increases in the levels of neurotransmitters, and the up-regulation of BDNF expression.Conclusion: The results suggested that SJG exerted a significant antidepressant effect, most probably via regulation of related neurotransmitters (including DA, NE, and 5-HT) and BDNF in the brain. Keywords: Shu-Gan-Jie-Yu granule, Antidepressant, dopamine, norepinephrine, 5-hydroxytryptamine, brain-derived neurotrophic facto

Chronic Arsenic Exposure and Angiogenesis in Human Bronchial Epithelial Cells via the ROS/miR-199a-5p/HIF-1α/COX-2 Pathway.

Background: Environmental and occupational exposure to arsenic is a major public health concern. Although it has been identified as a human carcinogen, the molecular mechanism underlying the arsenic-induced carcinogenesis is not well understood.Objectives: We aimed to determine the role and mechanisms of miRNAs in arsenic-induced tumor angiogenesis and tumor growth.Methods: We utilized an in vitro model in which human lung epithelial BEAS-2B cells were transformed through long-term exposure to arsenic. A human xenograft tumor model was established to assess tumor angiogenesis and tumor growth in vivo. Tube formation assay and chorioallantoic membranes assay were used to assess tumor angiogenesis.Results: We found that miR-199a-5p expression levels were more than 100-fold lower in arsenic-transformed cells than parental cells. Re-expression of miR-199a-5p impaired arsenic-induced angiogenesis and tumor growth through its direct targets HIF-1α and COX-2. We further showed that arsenic induced COX-2 expression through HIF-1 regulation at the transcriptional level. In addition, we demonstrated that reactive oxygen species are an upstream event of miR-199a-5p/ HIF-1α/COX-2 pathway in arsenic-induced carcinogenesis.Conclusion: The findings establish critical roles of miR-199a-5p and its downstream targets HIF-1/COX-2 in arsenic-induced tumor growth and angiogenesis.Citation: He J, Wang M, Jiang Y, Chen Q, Xu S, Xu Q, Jiang BH, Liu LZ. 2014. Chronic arsenic exposure and angiogenesis in human bronchial epithelial cells via the ROS/miR-199a-5p/HIF-1α/COX-2 Pathway. Environ Health Perspect 122:255-261; http://dx.doi.org/10.1289/ehp.1307545

Efficient, edge-aware, combined color quantization and dithering

Abstract—In this paper we present a novel algorithm to simultaneously accomplish color quantization and dithering of images. This is achieved by minimizing a perception-based cost function which considers pixel-wise differences between filtered versions of the quantized image and the input image. We use edge aware filters in defining the cost function to avoid mixing colors on opposite sides of an edge. The importance of each pixel is weighted according to its saliency. To rapidly minimize the cost function, we use a modified multi-scale iterative conditional mode (ICM) algorithm which updates one pixel a time while keeping other pixels unchanged. As ICM is a local method, careful initialization is required to prevent termination at a local minimum far from the global one. To address this problem, we initialize ICM with a palette generated by a modified median-cut method. Compared to previous approaches, our method can produce high quality results with fewer visual artifacts but also requires significantly less computational effort. Index Terms—Color quantization, dithering, optimization-based image processing. I