Exploratory Research: The Effects of Electronic Books on College Students

In recent years, the e-book has become more and more popular among college students, and it is much easier to be installed and set up in electronic equipment, such as laptop, Kindle, or IPad. A random sample (N=80) of undergraduate (n=25) and graduate (n=55) students not only use the e-book to read in class and library, but also at public places and at home. Of the respondents, 46% have a part-time job, 32% have a full-time job, and 22% are not employed. Fifty-five percent of the sample was male and 45% were female. The results of the survey questionnaire indicate that 55% sample claimed to spend hours on learning every week by using electronic tools, especially reading articles. Twenty-eight percent of the participants would take their electronic equipment to class instead of traditional textbooks; and 17% of them own at least two pieces of electronic equipment. Although most students rely on traditional paper print books, the population of college students applying e-book in their study life is increasing rapidly because many more “smart” and inexpensive electronic equipment (hardware) are displayed in markets in which an e-book can be installed. As everyone knows, textbooks in the United States are very expensive to be afforded by all college students. Consequently, the e-book offers a far less expensive alternative than paper print books

Secure Inter-domain Routing and Forwarding via Verifiable Forwarding Commitments

The Internet inter-domain routing system is vulnerable. On the control plane, the de facto Border Gateway Protocol (BGP) does not have built-in mechanisms to authenticate routing announcements, so an adversary can announce virtually arbitrary paths to hijack network traffic; on the data plane, it is difficult to ensure that actual forwarding path complies with the control plane decisions. The community has proposed significant research to secure the routing system. Yet, existing secure BGP protocols (e.g., BGPsec) are not incrementally deployable, and existing path authorization protocols are not compatible with the current Internet routing infrastructure. In this paper, we propose FC-BGP, the first secure Internet inter-domain routing system that can simultaneously authenticate BGP announcements and validate data plane forwarding in an efficient and incrementally-deployable manner. FC-BGP is built upon a novel primitive, name Forwarding Commitment, to certify an AS's routing intent on its directly connected hops. We analyze the security benefits of FC-BGP in the Internet at different deployment rates. Further, we implement a prototype of FC-BGP and extensively evaluate it over a large-scale overlay network with 100 virtual machines deployed globally. The results demonstrate that FC-BGP saves roughly 55% of the overhead required to validate BGP announcements compared with BGPsec, and meanwhile FC-BGP introduces a small overhead for building a globally-consistent view on the desirable forwarding paths.Comment: 16 pages, 17 figure

Student Physical Fitness Test System and Test Data Analysis System Based on Computer Vision

Computer vision technology is one of the main research directions of artificial intelligence. With the rapid growth of image or video data scale and the improvement of computing power, computer vision technology has achieved unprecedented development in recent years and is widely used in a variety of scenes. This study mainly discusses the design of student physical fitness test system and test data analysis system based on computer vision. This study is mainly based on the motion attitude determination algorithm to identify the motion. In hardware configuration, the key is CPU and GPU. The model realizes large-scale matrix computation based on the parallel computing power provided by GPU and uses CPU to realize data reading and preprocessing. The assessment controller is responsible for the transmission of instructions and status information and controls the operation of the entire pitch assessment system. It is the control center of the entire system. ZigBee wireless communication technology is adopted as the communication method of human posture measurement terminal and assessment controller. The input image is preprocessed through scaling and standardization. The image is scaled to the resolution of 224×224 when input, which is performed to realize data parallel training. The image was changed by means of random horizontal flip, random rotation, and color change to achieve the effect of expanding the dataset. Then, the test evaluation module was used to evaluate various test indexes of the body. During the sit-up test, nine out of 10 sit-ups can be accurately counted and the recognition rate reaches 90 percent. The results show that the system designed in this study has high accuracy and good performance, which can be used for the physical fitness test and test data analysis of students

Factors of COVID-19 Vaccination among Hong Kong Chinese Men Who Have Sex with Men during Months 5–8 since the Vaccine Rollout—General Factors and Factors Specific to This Population

This study investigated an under-researched topic regarding the prevalence of COVID-19 vaccination behavior among Chinese men who have sex with men (MSM) and the associations of this with general and MSM-specific perceptions grounded in the health belief model (HBM) and the theory of planned behaviors (TPB). A total of 400 Chinese MSM were recruited from multiple sources (site recruitment, online recruitment, and peer referral) in Hong Kong from July to October 2021, who then participated in a structured telephone interview. Of all the participants, the prevalence of COVID-19 vaccination (i.e., taking at least one dose of COVID-19 vaccination) was 78.3%. Multivariable logistic regression analyses showed that, after adjusting for background factors, (1) the general and MSM-specific HBM variables of perceived benefits and self-efficacy were positively associated with COVID-19 vaccination behavior; (2) the items or scale of general/MSM-specific perceived barriers and social norms were negatively associated with COVID-19 vaccination behavior; (3) the general perceived severity and MSM-specific perceived susceptibility, perceived severity, and cue to action were not significantly associated with COVID-19 vaccination behavior. The findings suggest that the HBM and social norm construct of the TPB only partially explained the participant’s COVID-19 vaccination behavior. Health promotion may need to focus more on modifying perceptions related to COVID-19 vaccination rather than COVID-19

UV/ozone induced physicochemical transformations of polystyrene nanoparticles and their aggregation tendency and kinetics with natural organic matter in aqueous systems.

Once discharged into the environment, plastics debris are unavoidably subjected to natural weathering processes. Unfortunately, the impact of weathering on the aggregation tendency and kinetics of nanoplastics in complex environmental matrices is poorly understood. Here, we investigated the influence of weathering as induced by UV and O3 treatments, on the aggregation of polystyrene nanoparticles (PSNPs) in simulated waters containing representative organic molecules (humic acid, lysozyme, and alginate) and in natural waters. Results showed that UV/O3 weathering-induced physicochemical transformations of PSNPs, particularly the formation of oxygen-containing functional groups and the increase in hydrophilicity, altered the aggregation state of PSNPs to different extents. The presence of organic molecules destabilized the UV-aged PSNPs with strength of lysozyme > alginate > humic acid, owing to the decrease of sorption of macromolecules on their surface. Differently, the O3-aged PSNPs displayed strong stability in the absence or presence of organic molecules (except for lysozyme), probably due to steric repulsion arising from the leakage of endogenous organic matters. This work demonstrates that the aggregation behavior of PSNPs is determined by the complex interplays among weathering, natural organic matter, and solution chemistry, and provides significant insights into the fate and transport of PSNPs in realistic scenarios

Hormonal and inflammatory signatures of different mood episodes in bipolar disorder: a large-scale clinical study

Abstract Background Bipolar disorder (BD) is characterized by intensive mood fluctuations. While hormones imbalance plays important role in the mood swings, it is unknown whether peripheral hormones profiles could differentiate the manic and depressive mood episodes in BD. In this study, we investigated the changes of various hormones and inflammatory markers across distinct mood episodes of BD in a large clinical study to provide mood episode-specific peripheral biomarkers for BD. Methods A total of 8332 BD patients (n = 2679 depressive episode; n = 5653 manic episode) were included. All patients were in acute state of mood episodes and need hospitalization. A panel of blood tests were performed for levels of sex hormones (serum levels of testosterone, estradiol, and progesterone), stress hormones (adrenocorticotropic hormone and cortisol), and an inflammation marker (C-reactive protein, CRP). A receiver operating characteristic (ROC) curve was used to analyze the discriminatory potential of the biomarkers for mood episodes. Results In overall comparison between mood episodes, the BD patients expressed higher levels of testosterone, estradiol, progesterone, and CRP (P < 0.001) and lower adrenocorticotropic hormone (ACTH) level (P < 0.001) during manic episode. The episode-specific changes of testosterone, ACTH, and CRP levels remained between the two groups (P < 0.001) after correction for the confounding factors including age, sex, BMI, occupation, marital status, tobacco use, alcohol consumption, psychotic symptoms, and age at onset. Furthermore, we found a sex- and age-specific impact of combined biomarkers in mood episodes in male BD patients aged ≥ 45 years (AUC = 0.70, 95% CI, 0.634–0.747), not in females. Conclusions While both hormone and inflammatory change is independently associated with mood episodes, we found that the combination of sex hormones, stress hormones and CRP could be more effective to differentiate the manic and depressive episode. The biological signatures of mood episodes in BD patients may be sex- and age-specific. Our findings not only provide mood episode-related biological markers, but also better support for targeted intervention in BD treatments

Wafer-scale functional circuits based on two dimensional semiconductors with fabrication optimized by machine learning

10.1038/s41467-021-26230-xNature Communications121595