Fast Neighbor Discovery for Wireless Ad Hoc Network with Successive Interference Cancellation

Neighbor discovery (ND) is a key step in wireless ad hoc network, which directly affects the efficiency of wireless networking. Improving the speed of ND has always been the goal of ND algorithms. The classical ND algorithms lose packets due to the collision of multiple packets, which greatly affects the speed of the ND algorithms. Traditional methods detect packet collision and implement retransmission when encountering packet loss. However, they does not solve the packet collision problem and the performance improvement of ND algorithms is limited. In this paper, the successive interference cancellation (SIC) technology is introduced into the ND algorithms to unpack multiple collision packets by distinguishing multiple packets in the power domain. Besides, the multi-packet reception (MPR) is further applied to reduce the probability of packet collision by distinguishing multiple received packets, thus further improving the speed of ND algorithms. Six ND algorithms, namely completely random algorithm (CRA), CRA based on SIC (CRA-SIC), CRA based on SIC and MPR (CRA-SIC-MPR), scan-based algorithm (SBA), SBA based on SIC (SBA-SIC), and SBA based on SIC and MPR (SBA-SIC-MPR), are theoretically analyzed and verified by simulation. The simulation results show that SIC and MPR reduce the ND time of SBA by 69.02% and CRA by 66.03% averagely.Comment: 16 pages, 16 figure

Inflammation-coagulation response and thrombotic effects induced by silica nanoparticles in zebrafish embryos

<p>Nowadays, nanotechnology environmental health and safety (nanoEHS) is gaining attention. We previously found that silica nanoparticles (SiNPs) could induce vascular endothelial damage. However, the subsequent toxicologic response to SiNPs-induced endothelial damage was still largely unknown. In this study, we explored the inflammation–coagulation response and thrombotic effects of SiNPs in endothelial cells and zebrafish embryos. For <i>in vitro</i> study, swollen mitochondria and autophagosome were observed in ultrastructural analysis. The cytoskeleton organization was disrupted by SiNPs in vascular endothelial cells. The release of proinflammatory and procoagulant cytokines including IL-6, IL-8, MCP-1, PECAM-1, TF and vWF, were markedly elevated in a dose-dependent manner. For <i>in vivo</i> study, based on the NOAEL for dosimetry selection, and using two transgenic zebrafish, Tg(mpo:GFP) and Tg(fli-1:EGFP), SiNPs-induced neutrophil-mediated inflammation and impaired vascular endothelial cells. With the dosage higher than NOAEL, SiNPs significantly decreased blood flow and velocity, exhibiting a blood hypercoagulable state in zebrafish embryos. The thrombotic effect was assessed by <i>o</i>-dianisidine staining, showed that an increasing of erythrocyte aggregation occurred in SiNPs-treated zebrafish. Microarray analysis was used to screen the possible genes for inflammation–coagulation response to SiNPs in zebrafish, and the JAK1/TF signaling pathway was further verified by qRT-PCR and Western blot assays. For in-deepth study, <i>il6st</i> was knocked down with specific morpholinos. The whole-mount <i>in situ</i> hybridization and qRT-PCR analysis showed that the expression <i>jak1</i> and <i>f3b</i> were attenuated in <i>il6st</i> knockdown groups. In summary, our data demonstrated that SiNPs could induce inflammation–coagulation response and thrombotic effects via JAK1/TF signaling pathway.</p

Gab2 Ablation Reverses the Stemness of HER2-Overexpressing Breast Cancer Cells

Background/Aims: HER2 has been implicated in mammary tumorigenesis as well as aggressive tumor growth and metastasis. Its overexpression is related to a poor prognosis and chemoresistance in breast cancer patients. Although Grb2-associated binding protein 2 (Gab2) is important in the development and progression of human cancer, its effects and mechanisms in HER2-overexpressing breast cancer are unclear. Methods: Clone formation and MTT assays were used to examine cell proliferation. To detect the effect of Gab2 on the stemness of breast cancer cells, we used flow cytometry, a sphere formation assay, real-time PCR, and western blot. An animal model was created to validate the effect of Gab2 on tumor growth in vivo. Tissue slides were analyzed by immunohistochemistry. Results: Knockdown of Gab2 suppressed PI3K/AKT and MAPK/ERK pathway activity. Gab2 ablation also reduced the stemness of HER2-overexpressing breast cancer cells. In vivo, knockdown of Gab2 inhibited tumor growth. Conclusion: This study unveils a potential function of Gab2 in HER2-overexpressing breast cancer cells. Gab2 might be a potential target in the clinical therapy of HER2-overexpressing breast carcinoma

Consistencies and differences in posttraumatic stress disorder and depression trajectories from the Wenchuan earthquake among children over a 4-year period

Background: Posttraumatic stress disorder (PTSD) and depression are the most prevalent mental disorders following disasters, and they often co-occur. The current study investigated trajectories of PTSD and depression among children after exposure to the Wenchuan earthquake and identified factors associated with PTSD or depression trajectories. Methods: Three hundred children who were exposed to the Wenchuan earthquake reported PTSD and depression symptoms 4, 16, 29, 40 and 52 months after the disaster, and potential predictors (age, earthquake exposure, prequake trauma and parental relationship) were identified. The PTSD and depression trajectories were identified with latent growth mixture modeling (LGMM), and the predictors were explored with multinomial logistic regression. Results: Two depression trajectories emerged: resilient (66.2%) and chronic (33.8%). Three PTSD trajectories emerged: resilient (74.9%), recovery (7.5%) and relapsing (17.7%). Overall, 57.3% of the children had low depression and PTSD symptoms over four years. Depression trajectories were significantly predicted by age and parental relationship, while PTSD trajectories were significantly predicted by trauma exposure and prequake trauma experience. Limitations: The children's prequake mental health statuses were unknown, and all assessments relied on self report questionnaires. Conclusion: The postdisaster developmental course of depression was more stable than that of PTSD, and PTSD and depression had different risk factors. Previous studies that focus only on PTSD or depression trajectories may overestimate children's resilient responses. Longer-term postdisaster intervention should pay more attention to depression than to PTSD

Traumatic experiences and posttraumatic stress disorder among Chinese rural-to-urban migrant children

Background: Children and adolescents are in the developmental periods with the highest risk of experiencing multiple types of traumatic experiences (TEs). Immigrant children are more likely than other children to be exposed to TEs and have a higher risk of mental health problems. However, no epidemiological study has reported the prevalence of TEs and the associated development of posttraumatic stress disorder (PTSD) among Chinese children. Methods: The present study focused on trauma exposure among rural-to-urban migrant Chinese children. A large-scale (N = 16,140) cross-sectional survey of rural-to-urban migrant workers&#39; children in grades 4 to 9 was conducted in Beijing. Lifetime exposure to accidents and injuries, interpersonal violence, and trauma within the social network or witnessing traumatic events were measured along with PTSD. Results: Nearly half of the participants (47.06%) had experienced TEs, and 6.68% of those children met the cutoff for PTSD. Trauma exposure was associated with gender, age, quality of life, parents&#39; marital status, caregivers before the child started school and father&#39;s education level. Overall, interpersonal violence was associated with the highest rates of PTSD, and disasters were associated with the lowest rates of PTSD. Limitations: The cross-sectional survey design limited the ability to document temporal ordering, and the assessment of lifetime TEs was based on retrospective recall. Conclusions: The present study is the first epidemiological study of TEs in Chinese rural-to-urban migrant children. TEs are potentially fairly common among this population. Interventions designed to prevent PTSD should target different TE types according to the victim&#39;s gender.</p

The Influence of Organizational Social Network on Enterprise Collaborative Innovation&#x2014;Mediating Role of Knowledge Sharing and Moderating Effect of Digital Construction

This paper mainly discusses the influence of organizational social network on enterprise collaborative innovation, as well as the intermediary role of knowledge sharing and the regulatory role of digital construction. Based on social exchange theory and social cognition theory, an integration model of organizational social network influencing enterprise collaborative innovation is constructed. The hierarchical regression analysis was used to sample the high-tech enterprises in China&#x2019;s Yangtze River Delta. Statistical analysis of 212 questionnaires was performed using SPSS and AMOS. It is found that organizational social network has a significant positive impact on enterprise collaborative innovation. Knowledge sharing plays a partially mediating role in the relationship between the organizational social network and enterprise collaborative innovation. Digital construction positively moderates the relationship between organizational social network and enterprise collaborative innovation. In general, In general, the research findings show that improving the construction of organizational social networks and enhancing employees&#x2019; knowledge sharing behavior can improve enterprises&#x2019; collaborative innovation ability. In addition, in the context of highly digital construction, the effect of organizational social networks on improving enterprise collaborative innovation is more obvious

How Maternal Trauma Exposure Contributed to Children's Depressive Symptoms following the Wenchuan Earthquake: A Multiple Mediation Model Study

Although well-established literature has indicated the burden of mental health among victims after the Wenchuan earthquake, no research has focused on the mental health of mothers and their children who experienced the earthquake and were pregnant during or shortly after it. This study investigates the relationship between maternal trauma exposure (TE) and children's depressive symptoms after the Wenchuan earthquake and explores the risk and protective factors underlying this relationship. A sample of 547 mother-child dyads, in which the mother experienced the Wenchuan earthquake, was used to assess maternal depressive symptoms, maternal TE, children's depressive symptoms, children's perceived impact of the earthquake and maternal posttraumatic growth (PTG). The results showed that maternal TE had two significant one-step indirect associations with children's depressive symptoms (through children's perceived impact of the earthquake and maternal PTG) and one two-step indirect association with children's depressive symptoms (through maternal depressive symptoms via children's perceived impact of the earthquake). The results indicated that maternal depressive symptoms, children's perceived impact of the earthquake and maternal PTG mediated the association between maternal TE and children's depressive symptoms. These findings highlight the importance of mothers in supporting the mental health of these children. Maternal depressive symptoms and PTG, two posttraumatic outcomes, played positive and negative roles in the intergenerational transmission of trauma. Thus, post-disaster interventions should reduce the maternal transmission of trauma-related information and improve maternal PTG to support children's mental health

Trajectories of posttraumatic stress disorders among children after the Wenchuan earthquake: a four-year longitudinal study

Background: Previous research has demonstrated heterogeneous patterns of posttraumatic stress disorder (PTSD) among children following disasters. However, no clear consensus has been reached regarding the postdisaster trajectories of PTSD among children. Objective: The current study examined the trajectories of PTSD among children after exposure to the Wenchuan earthquake and explored potential predictors of distinct PTSD trajectories. Methods: A four-year longitudinal study was conducted to follow 301 children who were evaluated for PTSD symptoms following the Wenchuan earthquake. Trauma exposure and some pre-existing characteristics were measured at four months after the disaster, and PTSD symptoms were measured at 4, 16, 29, 40 and 52 months after the disaster. The trajectories were identified with Latent Growth Mixture Modelling, and the predictors were explored with multinomial logistic regression. Results: The following three latent PTSD trajectories were found among children: resilient (74.9%), relapsing (17.7%) and recovery (7.5%). Trauma exposure was more likely to be related to a more severe trajectory of PTSD, having experienced prequake trauma was more likely to be related to the recovery trajectory and school 2 was more likely to be related to the relapsing trajectory. Conclusion: These findings provide novel insights into children's postdisaster response patterns. Individual heterogeneity existed in posttraumatic reactions. This longer-term longitudinal study captured more detailed and accurate information about the development of these trajectories. Trauma exposure and previous traumatic experience were linked to malignant development of PTSD

A Large Sample Survey of Tibetan People on the Qinghai-Tibet Plateau: Current Situation of Depression and Risk Factors

Background: A depressive state is a negative emotional state characterized by abnormal dejection and unpleasant mood. Long-term depressive symptoms can result in psychological disorders such as depression. However, little is known about the depression status and risk factors of the Tibetan people on the Qinghai-Tibet Plateau. Objective: This study explores the depression status of the Tibetan people to better promote ethnic minorities&#39; physical and mental health. Participants and Setting: The Center for Epidemiologic Studies Depression Scale (CES-D) was administered to 24,141 Tibetan people from Yushu Prefecture; the average age was 34.33 years (SD = 9.18, range = 18-94 years). Materials and Methods: Participants completed questionnaires collecting demographic information and evaluating symptoms of depression. Results: The depression prevalence was higher at high altitudes, and there may be a significant positive correlation between depression rates and altitude. Significant differences were found for each demographic variable. Participants with depressive symptoms (scores &gt;= 8) accounted for 52.3% of the total sample, and participants with depression (scores &gt;= 14) accounted for 28.6%. The binary logistic regression results showed that alcohol drinkers, unmarried participants, participants with high self-assessed socioeconomic status, participants with a high income level, and those with a middle-school education were more likely to be depressed. Conclusions: The results provide the first evidence that the prevalence of depression in Tibetans of the Qinghai-Tibet Plateau is higher than that in the general Chinese population and that reported in Western studies, a finding that may be related to cultural differences and chronic hypoxia caused by the high altitude. This paper offers insight into the mental health status of people living in plateau areas and provides a basis for formulating pertinent mental health policy.</p