Factors influencing engagement in premarital sex among Vietnamese young adults: a qualitative study.

Background With the rising trend of sexual engagement among Vietnamese young adults in recent years, concerns were raised over the issue of premarital sex and its potential health consequences. In order to prevent such consequences and further promote health, an in-depth understanding of factors influencing young people to have premarital sex would be valuable. Objective To generate a grounded theory explaining factors influencing engagement in premarital sex among Vietnamese young adults. Subjects Vietnamese adults aged 18-24 who have voluntarily engaged in premarital sex (n = 18). Method The study was conducted using the grounded theory approach by Glaser. Purposive and theoretical sampling was used. Ten in-depth interviews and three additional focus group discussions were carried out. The interviews were audio-recorded and transcribed verbatim. Data analysis involved using the constant comparative method and open and theoretical coding. Sampling, data collection and data analysis happened simultaneously until theoretical saturation was achieved. Results The grounded theory is constructed around six emergent themes: (a) desire as the 'direct cause'; (b) the facilitators; (c) social changes; (d) media; (e) peer and (f) absence of family. The latter four themes are 'indirect causes' that influence through desire and the facilitators. Conclusion The study has contributed a grounded theory that identified the factors and described their relationships in a comprehensive way. It suggested a need for a reliable source of information to be tailor-designed to suit young people. Additionally, the stigma of talking about sex needs to be reduced to allow for more open discussions on sex and sexual health

Unsupervised deep learning-based reconfigurable intelligent surface aided broadcasting communications in industrial IoTs

This paper presents a general system framework which lays the foundation for Reconfigurable Intelligent Surface (RIS)-enhanced broadcast communications in Industrial Internet of Things (IIoTs). In our system model, we consider multiple sensor clusters co-existing in a smart factory where the direct links between these clusters and a central base station (BS) is blocked completely. In this context, an RIS is utilized to reflect signals broadcast from BS toward cluster heads (CHs) which act as a representative of clusters, where BS only has access to the statistical distribution of the channel state information (CSI). An analytical upper bound of the total ergodic spectral efficiency and an approximation of outage probability are derived. Based on these analytical results, two algorithms are introduced to control the phase shifts at RIS, which are the Riemannian conjugate gradient (RCG) method and the deep neural network (DNN) method. While the RCG algorithm operates based on the conventional iterative method, the DNN technique relies on unsupervised deep learning. Our numerical results show that the both algorithms achieve satisfactory performance based on only statistical CSI. In addition, compared to the RCG scheme, using deep learning reduces the computational latency by more than 10 times with an almost identical total ergodic spectral efficiency achieved. These numerical results reveal that while using conventional RCG method may provide unsatisfactory latency, DNN technique shows much promise for enabling RIS in ultra reliable and low latency communications (URLLC) in the context of IIoTs

Transgenerational interactions between pesticide exposure and warming in a vector mosquito

While transgenerational plasticity may buffer ectotherms to warming and pesticides separately, it remains unknown how combined exposure to warming and pesticides in the parental generation shapes the vulnerability to these stressors in the offspring. We studied the transgenerational effects of single and combined exposure to warming (4°C increase) and the pesticide chlorpyrifos on life history traits of the vector mosquito Culex pipiens. Parental exposure to a single stressor, either warming or the pesticide, had negative effects on the offspring: both parental exposure to warming and to the pesticide resulted in an overall lower offspring survival, and a delayed offspring metamorphosis. Parental exposure to a single stressor did, however, not alter the vulnerability of the offspring to the same stressor in terms of survival. Parental pesticide exposure resulted in larger offspring when the offspring experienced the same stressor as the parents. Within both the parental and offspring generations, warming made the pesticide more toxic in terms of survival. Yet, this synergism disappeared in the offspring of parents exposed to both stressors simultaneously because in this condition the pesticide was already more lethal at the lower temperature. Our results indicate that transgenerational effects will not increase the ability of this vector species to deal with pesticides in a warming world. Bifactorial transgenerational experiments are crucial to understand the combined impact of warming and pesticides across generations, hence to assess the efficacy of vector control in a warming world.status: publishe

Integrable and superintegrable systems associated with multi-sums of products

We construct and study certain Liouville integrable, superintegrable, and non-commutative integrable systems, which are associated with multi-sums of products.Comment: 26 pages, submitted to Proceedings of the royal society