Abstract
The human hippocampus is involved in forming new memories: damage impairs memory. The dual stream model suggests that object “what” representations from ventral stream temporal cortex ...project to the hippocampus via the perirhinal and then lateral entorhinal cortex, and spatial “where” representations from the dorsal parietal stream via the parahippocampal gyrus and then medial entorhinal cortex. The hippocampus can then associate these inputs to form episodic memories of what happened where. Diffusion tractography was used to reveal the direct connections of hippocampal system areas in humans. This provides evidence that the human hippocampus has extensive direct cortical connections, with connections that bypass the entorhinal cortex to connect with the perirhinal and parahippocampal cortex, with the temporal pole, with the posterior and retrosplenial cingulate cortex, and even with early sensory cortical areas. The connections are less hierarchical and segregated than in the dual stream model. This provides a foundation for a conceptualization for how the hippocampal memory system connects with the cerebral cortex and operates in humans. One implication is that prehippocampal cortical areas such as the parahippocampal TF and TH subregions and perirhinal cortices may implement specialized computations that can benefit from inputs from the dorsal and ventral streams.
Numerous studies have found that repetitive transcranial magnetic stimulation (rTMS) modulates plasticity. rTMS has often been used to change neural networks underlying learning, often under the ...assumption that the mechanism of rTMS-induced plasticity should be highly similar to that associated with learning. The presence of visual perceptual learning (VPL) reveals the plasticity of early visual systems, which is formed through multiple phases. Hence, we tested how high-frequency (HF) rTMS and VPL modulate the effect of visual plasticity by investigating neurometabolic changes in early visual areas. We employed an excitatory-to-inhibitory (E/I) ratio, which refers to glutamate concentration divided by GABA+ concentration, as an index of the degree of plasticity. We compared neurotransmitter concentration changes after applying HF rTMS to the visual cortex with those after training in a visual task, in otherwise identical procedures. Both the time courses of the E/I ratios and neurotransmitter contributions to the E/I ratio significantly differed between HF rTMS and training conditions. The peak E/I ratio occurred 3.5 h after HF rTMS with decreased GABA+, whereas the peak E/I ratio occurred 0.5 h after visual training with increased glutamate. Furthermore, HF rTMS temporally decreased the thresholds for detecting phosphene and perceiving low-contrast stimuli, indicating increased visual plasticity. These results suggest that plasticity in early visual areas induced by HF rTMS is not as involved in the early phase of development of VPL that occurs during and immediately after training.
IntroductionFive workers engaged in non-destructive testing (NDT) were diagnosed with leukemia and visited the Occupational Injury and Disease Prevention Center for the help of assessment for ...occupational disease in Taiwan during 2018 and 2019. NDT belongs to industrial radiography in the classification of radiation work, and the purpose of this study is to investigate the ionizing radiation exposure among workers in the industry.MethodUsing the National Radiation Workers Dose Database of the Atomic Energy Commission of Taiwan Executive Yuan from 2000 to 2019 to analyze the values of the ionizing radiation badges among the industrial radiography group and other groups exposed to ionizing radiation over these years. The cumulative personal measurement was also analyzed using the characteristics of the longitudinal databases.ResultsDuring this period, workers with dose values greater than the lowest measurable value accounted for 13.29% of the total population potentially exposed to radiation at work, compared to 26.57% of workers in industrial radiography. We also found that the mean annual median dose value for all workers possibly exposes to ionizing radiation was 0.43 mSv and in industrial radiography it was 1.21 mSv. Since 2005, most of the practitioners in the industrial radiography industry have an annual cumulative exposure of more than 20mSv. Moreover, the average personal 20-year cumulative measurement is 7.82 mSv for all ionizing radiation workers and 29.26 mSv among workers engaged in industrial radiography.ConclusionIndustrial radiography workers may have higher exposure to ionizing radiation. This is important to prevent ionizing radiation-related occupational diseases in industrial radiography or NDT workers.
Vaccination appears to be one of the effective strategies to control the COVID-19 pandemic. However, the challenge of vaccine hesitancy may lower the uptake rate and affect overall vaccine efficacy. ...Being a low-risk group in terms of serious consequences of infection, university students may possess low motivation to get vaccinated. Therefore, an expanded Protection Motivation Theory (PMT) incorporating perceived knowledge, adaptive response, and maladaptive response was proposed to investigate the COVID-19 vaccination intention among Taiwanese university students. University students (n = 924; 575 males; mean age = 25.29 years) completed an online survey during January to February 2021. The proposed expanded PMT model was examined using structural equation modeling (SEM). The results showed that perceived knowledge was significantly associated with coping appraisal (standardized coefficient (β) = 0.820; p < 0.001), and coping appraisal was significantly associated with adaptive response (β = 0.852; p < 0.001), maladaptive response (β = 0.300; p < 0.001) and intention (β = 0.533; p = 0.009). Moreover, maladaptive response (β = −0.173; p = 0.001) but not adaptive response (β = 0.148; p = 0.482) was significantly and negatively associated with intention. The present study’s results demonstrated a positive path between perceived knowledge, coping appraisal, and intention among university students. Therefore, improving knowledge among this population may increase the intention to uptake the vaccine.
Abstract
Background
Insomnia and suicidal thoughts are two of the negative impacts that have been caused by the COVID-19 pandemic. Identifying the factors that contribute to these psychological ...problems may help develop strategies to sustain the mental health of the public. The present study examined the psychosocial impacts caused by the COVID-19 pandemic among different populations in Taiwan, and investigated the relationships between these psychosocial variables, insomnia, and suicidal thoughts.
Methods
Between September 2020 and May 2021, online questionnaires including psychometrically validated scales were distributed to a convenience sample of outpatients (
n
= 205), healthcare workers (HCWs) (
n
= 500), and individuals in the general population (
n
= 1200) in Taiwan to collect data regarding their insomnia severity, suicidal thoughts, fear of COVID-19, trust of information, and resilience. Multivariate logistic regression methods were used to identify variables associated with suicidal thoughts and insomnia.
Results
Greater fear of COVID-19 was significantly associated with suicidal thoughts: odds ratios (ORs) with 95% confidence interval (CI) = 1.155 (1.002–1.330) for outpatients; 1.127 (1.035–1.228) for HCWs; and 1.100 (1.130–1.222) for those in the general population. Higher resilience was significantly associated with lower insomnia: OR (95% CI) = 0.819 (0.725–0.926) for outpatients; 0.803 (0.728–0.887), for HCWs; 0.829 (0.785–0.875), and for those in the general population. In addition, there was a statistically significant association between insomnia diagnosis and greater fear of COVID-19 among HCWs (OR 95% CI = 1.102 1.062–1.144) and those in the general population (OR 95% CI = 1.079 1.053–1.106). Among outpatients, there was a statistically significant association between suicidal thoughts and lower trust of information (OR 95% CI = 0.794 0.646–0.976), while among those in the general population there was a statistically significant association between suicidal thoughts and higher insomnia severity (OR 95% CI = 1.175 1.13–1.222). A statistically significant association was also found between insomnia diagnosis and higher suicidal thoughts among those in the general population (OR 95% CI = 3.455 2.338–5.106).
Conclusions
Trust of information, fear, and resilience were important factors for suppressing suicidal thoughts and insomnia among the three study populations. Health policies that monitor psychological status and build resiliency of the public are recommended to help develop tailored strategies for different populations affected by the COVID-19 pandemic.
Nonrapid eye movement (NREM) sleep is associated with fading consciousness in humans. Recent neuroimaging studies have demonstrated the spatiotemporal alterations of the brain functional connectivity ...(FC) in NREM sleep, suggesting the changes of information integration in the sleeping brain. However, the common stationarity assumption in FC does not satisfactorily explain the dynamic process of information integration during sleep. The dynamic FC (dFC) across brain networks is speculated to better reflect the time‐varying information propagation during sleep. Accordingly, we conducted simultaneous EEG‐fMRI recordings involving 12 healthy men during sleep and observed dFC across sleep stages using the sliding‐window approach. We divided dFC into two aspects: mean dFC (dFCmean) and variance dFC (dFCvar). A high dFCmean indicates stable brain network integrity, whereas a high dFCvar indicates instability of information transfer within and between functional networks. For the network‐based dFC, the dFCvar were negatively correlated with the dFCmean across the waking and three NREM sleep stages. As sleep deepened, the dFCmean decreased (N0~N1 > N2 > N3), whereas the dFCvar peaked during the N2 stage (N0~N1 < N3 < N2). The highest dFCvar during the N2 stage indicated the unstable synchronizations across the entire brain. In the N3 stage, the overall disrupted network integration was observed through the lowest dFCmean and elevated dFCvar, compared with N0 and N1. Conclusively, when the network specificity (dFCmean) breaks down, the consciousness dissipates with increasing variability of information exchange (dFCvar).
Ovarian steroids, estradiol and progesterone, play central roles in regulating female reproduction by acting as both positive and negative regulators of gonadotropin-releasing hormone (GnRH) ...secretion in the hypothalamus. Recent studies have identified kisspeptin neurons of the hypothalamus as the target of estrogenic regulation of GnRH secretion. In this study, we aimed to determine the significance of progesterone receptor (PGR) expression in the kisspeptin neurons. To this end, the Pgr gene was selectively ablated in mouse kisspeptin neurons and the reproductive consequence assessed. The hypothalamus of the Pgr deficient female mouse expressed kisspeptin, the pituitary released LH in response to GnRH stimulation, and the ovary ovulated when stimulated with gonadotropins. However, the mutant mouse gradually lost cyclicity, was unable to generate a LH surge in response to rising estradiol, and eventually became infertile. Taken together, these results indicate that the loss of PGR impairs kisspeptin secretory machinery and therefore that PGR plays a critical role in regulating kisspeptin secretion.
Distributed denial of service is one of the most critical threats to the availability of Internet services. A botnet with only 0.01 percent of the 50 billion connected devices in the Internet of ...Things is sufficient to launch a massive DDoS flooding attack that could exhaust resources and interrupt any target. However, the mobility of user equipment and the distinctive characteristics of traffic behavior in mobile networks also limit the detection capabilities of traditional anti-DDoS techniques. In this article, we present a novel collaborative DDoS defense architecture called MECPASS to mitigate the attack traffic from mobile devices. Our design involves two filtering hierarchies. First, filters at edge computing servers (i.e., local nodes) seek to prevent spoofing attacks and anomalous traffic near sources as much as possible. Second, global analyzers located at cloud servers (i.e., central nodes) classify the traffic of the entire monitored network and unveil suspicious behaviors by periodically aggregating data from the local nodes. We have explored the effectiveness of our system on various types of application- layer DDoS attacks in the context of web servers. The simulation results show that MECPASS can effectively defend and clean an Internet service provider core network from the junk traffic of compromised UEs, while maintaining the false-positive rate of its detection engine at less than 1 percent.
The influence of hydrothermal treatments on the structural properties and digestibility of water caltrop starch was investigated. Scanning electron microscopy (SEM) showed some small dents on the ...surface of starch granules for samples treated with heat moisture treatment (HMT), but not for samples treated with annealing (ANN) which generally showed smoother surfaces. The gelatinization temperature of starch was generally increased by hydrothermal treatments, accompanied by a trend of decreasing breakdown viscosity. These results implied the improvement of thermal and shearing stability, particularly for HMT in comparison to ANN. After being cooked, the native and ANN-modified water caltrop starch granules were essentially burst or destroyed. On the other hand, the margin of starch granules modified by HMT and dual hydrothermal treatments remained clear with some channels inside the starch granules. X-ray diffraction revealed that the crystalline pattern of water caltrop starch changed from the C
-type to the A-type and the relative crystallinity reduced with increasing moisture levels of HMT. Results of ANN-modified water caltrop starch were mostly similar to those of the native one. Moreover, water caltrop starch modified with HMT20 and dual modification contained a pronouncedly higher resistant starch content. These results suggested that HMT, ANN, and dual modification effectively modified the functional properties of water caltrop starch.
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