Accurate Estimation of Transport Coefficients Using Model-free Time Correlation Functions in Equilibrium Simulations

Transport coefficients, such as the diffusion coefficient and shear viscosity, are important material properties that are calculated in computer simulations. In this study, the criterion for the best estimation of viscosity, as an example of transport coefficients, is determined by using the Green-Kubo formula without any artificial models. The related algorithm is given by the estimation of the viscosities of polyethylene oxide solutions by using a molecular dynamics simulation for testing. The algorithm can be used in the simulations of complex systems with a long tail of correlations typically found in macromolecular and biological simulation systems.Comment: 8 pages, 5 figures, 1 tabl

Observations on facilitation and IOR in the Posner paradigm

In the Posner paradigm (Posner & Cohen, 1984), participants respond to a visual target preceded by a peripheral cue, either for a short or long stimulus onset asynchrony (SOA), and either at the same or a different location (Validity). Participants respond more quickly to targets when the target is cued by a stimulus at the same location for short SOAs (facilitation). This effect reverses for longer SOAs (Inhibition of Return, IOR). Previous research reported that the magnitude of facilitation and IOR was affected by physical characteristics of the cues (e.g., Lambert & Hockey, 1991; Pratt, Hillis, & Gold, 2001) and the targets (e.g., Reuter-Lorenz, Jha, & Rosenquist, 1996) in the COVAT paradigm. This thesis investigated the effect of physical characteristics of cues and targets and double cueing on facilitation and IOR. Exp. 1 aimed to examine the cue-target discriminability by manipulating the novelty of cues and targets. I found IOR but no facilitation. In addition, the cue-target discriminability did not affect the IOR, which was in line with the conclusion suggested by Pratt and colleagues (2001). In Exp. 2 I examined the effect of presenting onset and offset cues on facilitation and/ or IOR in different sequences of appearing and disappearing cues, labelled on-off and off-on cues. For on-off cueing, I found IOR but no facilitation. For off-on cueing, I found facilitation and no IOR for off-on cueing. This suggests that compared to on-off cues, off-on cues work more effectively in terms of capturing attention and that off-on cues can eliminate the otherwise robust IOR effect. In addition, for short SOA, the cue delayed the target detection for on-off cues but not for on-off cues. In Exp. 3A I examined the effects of the cue and target size on facilitation and IOR. IOR was found for both the small and large condition. Size did therefore not affect IOR for the long SOA. Facilitation was not found for either the small or large condition and instead, early IOR was found for the short SOA in the small size condition. In Exp. 3B I investigated the effect of changes in cue size on facilitation and IOR, using static cues similar to Exp. 3A as controls. I found no facilitation but observed IOR. Increased IOR was found for small cues compared to large cues in the static cue conditions. In Exp. 4A and Exp. 4B I used a double-cueing paradigm. By systematically varying SOA-D and the relative location between cue and target I studied the characteristics of facilitation as well as IOR. No matter whether single and double cueing was presented in intermixed or blocked trials, facilitation and IOR was found for single cueing, but not for double cueing. I speculate that the occurrence of facilitation for single cueing may be due to the temporal overlap of cues and targets between trials and blocks. The results for double cueing in Exp. 4A showed that IOR occurred at more than one location, that the most recently cued location produced the strongest IOR, and that IOR accumulated at the same location. When single and double cueing trials were presented in separate blocks, the second cue generated facilitation for short SOA between second cue and target and produced weaker IOR for long SOA between second cue and target. These results suggest that the second cue works effectively in terms of attracting attention, which is possibly due to the expectation of observers for target onset of the second cue. This thesis strongly supports the finding in previous research that in detection tasks facilitation is more difficult to occur whereas IOR is a robust effect (see, e.g., Collie et al., 2000; Mele et al., 2008; Tassinari et al., 1994; Tassinari & Berlucchi, 1995). This was observed when the experiment included only single and on-off cueing. Nevertheless, I found that the absence and presence of facilitation and IOR can be affected by the cue type and the number of cues. That is, for cue type, off-on cue triggered facilitation for the short SOA but eliminated IOR for the long SOA. For the number of cues, when only two cues preceded targets in a block, the second cue generated facilitation for short SOA between second cue and target and produced weaker IOR for long SOA between second cue and target, compared to when either one or two cues preceded targets in a block. The random effects of mixed models explained sufficient variance across subjects to improve estimates of facilitation and IOR and variability was mainly due to individual mean RTs (random intercepts) across conditions

Astrocyte-derived nitric oxide in manganese neurotoxicity: from cellular and molecular mechanisms underlying selective neuronal vulnerability in the basal ganglia to potential therapeutic modalities

Chronic exposure to manganese (Mn) causes the neurodegenerative movement disorder, manganism. A mouse model was developed to elucidate mechanisms involved in the etiology and progression of injury. Twelve-week old female C57Bl/6J mice were exposed to MnCl2 (100 mg/kg/day) by oral gavage daily for 8 weeks. After the experiment striatal dopamine (DA) content was decreased with the manifestation of hypoactivity. A distinct population of neurons was vulnerable to the effects of Mn, including enkephalin (ENK)-positive projection neurons, interneurons expressing neuronal nitric oxide synthetase (nNOS/NOS1), and choline acetyltransferase (ChAT)-expressing interneurons. Activation of surrounding astrocytes occurred with expression of inducible nitric oxide synthase (iNOS/NOS2) and production of nitric oxide (NO)/peroxynitrite (ONOO-). Activated astrocytes were detected primarily near the microvasculature in both the striatum and globus pallidus (GP). It is suggested that Mn exposure may damage the blood-brain barrier (BBB) and induce astrocytosis and NOS2 expression, subsequent NO production may cause the death of adjacent neurons. This hypothesis was also tested in an in vitro co-culture model. Differentiated pheochromocytoma cells (PC12 cells) were co-cultured with primary astrocytes and exposed to Mn and inflammatory cytokines. Mn and cytokines induced NOS2 expression and NO production in astrocytes, which correlated with apoptosis of PC12 cells. Apoptosis of PC12 cells was prevented by overexpression of a phosphorylation-deficient mutant of IúBñ that inhibited NOS2 expression in astrocytes. It is concluded that Mn-and cytokine-dependent apoptosis in PC12 cells requires astrocyte-derived NO and nuclear factor úB (NF-úB)-dependent expression of NOS2. To explore possible means of interdicting this inflammatory process in astrocytes, a noval pharmacologic ligands of the peroxisome proliferator-activated receptor gamma (PPARó) agonist, 1,1-Bis(3'-indolyl)-1-(p-trifluoromethylphenyl) methane (DIM-C-pPhCF3) were used in the same co-culture system. DIM-C-pPhCF3 protected PC12 cells from apoptosis through inhibition of NOS2 expression in astrocytes after Mn and cytokines exposure. By contrast, the PPARó antagonist, 2-chloro-5-nitrobenzanilide (GW9622), had the opposite effect, increasing both NO production in astrocytes and neuronal injury. It is concluded that PPARó is involved in the regulation of NOS2 expression in astrocytes and that agonists of PPARó may represent a potential treatment method for Mn neurotoxicity

Progress of Research on the Clinical Application of Radiation Protection Agents

With the advancement of nuclear technology, there is an increasing exposure of individuals to ionizing radiation. Incidents of radiation exposure occur occasionally, with the risk of radiation damage continuously rising. Radiation protectants are employed to prevent, alleviate, and treat ionizing radiation injuries. However, many current radiation protectants exhibit potent side effects, and there is currently no clinically established radiation protectant in routine use. Researchers have persistently endeavored to explore effective and low-toxicity radiation protectants. This article primarily focuses on internationally approved radiation protectants such as amifostine, dexrazoxane, phosphoramide mustard, polyethylene glycol-conjugated phosphoramide mustard, and sargramostim. Additionally, it discusses some natural antioxidants, resveratrol, and mesenchymal stem cells, which are currently undergoing clinical trials and promising to offer new avenues for the prevention and treatment of radiation injuries

Green transformational leadership and employee organizational citizenship behavior for the environment in the manufacturing industry: A social information processing perspective

The employee organizational citizenship behavior for the environment (OCBE) contributes to the improvement of the organization’s environment, its study is increasing in number. However, the psychological mechanism of promoting employee OCBE is still a missing link. Drawing on the theory of social information processing, this study seeks to establish the impact of green transformational leadership on employee OCBE and the mediating role of green organizational climate in this nexus. In addition, we have integrated environmental concerns to better explain the impact of this differentiation. The results show that: green transformational leadership has a significant positive impact on employee OCBE, and green organizational climate has a mediating effect on the impact of green transformational leadership on employee OCBE. Furthermore, environmental concern not only has a positive moderating effect on the influence of green transformational leadership on green organizational climate, but also positively moderates the impact of the influence of green transformational leadership on employee OCBE. This paper reveals the internal psychological mechanism of improving employee OCBE and provides ideas for promoting the sustainable development of enterprises

Paraoxon Attenuates Vascular Smooth Muscle Contraction through Inhibiting Ca2+ Influx in the Rabbit Thoracic Aorta

We investigated the effect of paraoxon on vascular contractility using organ baths in thoracic aortic rings of rabbits and examined the effect of paraoxon on calcium homeostasis using a whole-cell patch-clamp technique in isolated aortic smooth muscle cells of rabbits. The findings show that administration of paraoxon (30 μM) attenuated thoracic aorta contraction induced by phenylephrine (1 μM) and/or a high K+ environment (80 mM) in both the presence and absence of thoracic aortic endothelium. This inhibitory effect of paraoxon on vasoconstrictor-induced contraction was abolished in the absence of extracellular Ca2+, or in the presence of the Ca2+ channel inhibitor, verapamil. But atropine had little effect on the inhibitory effect of paraoxon on phenylephrine-induced contraction. Paraoxon also attenuated vascular smooth muscle contraction induced by the cumulative addition of CaCl2 and attenuated an increase of intracellular Ca2+ concentration induced by K+ in vascular smooth muscle cells. Moreover, paraoxon (30 μM) inhibited significantly L-type calcium current in isolated aortic smooth muscle cells of rabbits. In conclusion, our results demonstrate that paraoxon attenuates vasoconstrictor-induced contraction through inhibiting Ca2+ influx in the rabbits thoracic aorta

Task-switching costs disappear if non-Chinese participants respond to Chinese characters

In experiments with univalent target stimuli, task-switching costs can be eliminated if participants are unaware of the task rules and apply cue-target-response associations. However, in experiments with bivalent target stimuli, participants show task-switching costs. Participants may exhibit switch costs even when no task rules are provided in the instructions because they can infer the task rules. We tested this prediction by controlling the meaningfulness of cues and targets and therefore the ability to apply the task rules in 2 groups of participants. We compared the performance of Chinese and non-Chinese participants, who responded to Chinese numerals in an odd/even and high/low number task. In Experiment 1, Chinese participants, who knew Chinese characters and understood the task rules, showed task-switching costs. Non-Chinese participants on the other hand, who did not know Chinese characters, exhibited no switch costs. They applied a “target-first” strategy which means that they processed the target stimulus before the cue. In Experiment 2, we confirmed the absence of task-switching costs in Chinese participants using traditional Chinese numerals as target stimuli. Further, to determine how the target-first strategy affects switch costs, we manipulated the sequence of cue and target presentations. We conclude that task- switching costs can be eliminated more easily than previously thought, even for bivalent stimuli. The occurrence of task-switching costs depends on the approach used by participants and this may answer the puzzling question why humans typically do show task-switching costs whereas pigeons and monkeys do not

Static Semantics Reconstruction for Enhancing JavaScript-WebAssembly Multilingual Malware Detection

The emergence of WebAssembly allows attackers to hide the malicious functionalities of JavaScript malware in cross-language interoperations, termed JavaScript-WebAssembly multilingual malware (JWMM). However, existing anti-virus solutions based on static program analysis are still limited to monolingual code. As a result, their detection effectiveness decreases significantly against JWMM. The detection of JWMM is challenging due to the complex interoperations and semantic diversity between JavaScript and WebAssembly. To bridge this gap, we present JWBinder, the first technique aimed at enhancing the static detection of JWMM. JWBinder performs a language-specific data-flow analysis to capture the cross-language interoperations and then characterizes the functionalities of JWMM through a unified high-level structure called Inter-language Program Dependency Graph. The extensive evaluation on one of the most representative real-world anti-virus platforms, VirusTotal, shows that \system effectively enhances anti-virus systems from various vendors and increases the overall successful detection rate against JWMM from 49.1\% to 86.2\%. Additionally, we assess the side effects and runtime overhead of JWBinder, corroborating its practical viability in real-world applications.Comment: Accepted to ESORICS 202

Ten-year changes in the prevalence of overweight, obesity and central obesity among the Chinese adults in urban Shanghai, 1998–2007 — comparison of two cross-sectional surveys

BACKGROUND: In China, obesity is expected to increase rapidly in both urban and rural areas. However, there have been no comprehensive reports on secular trends in obesity prevalence among Chinese adults in urban Shanghai, which is the largest city in southern China. METHODS: In 1998–2001 and again in 2007–2008, two independent population-based cross-sectional surveys were conducted in Shanghai to investigate the prevalence of metabolic disorders. These surveys obtained height, waist circumference (WC), and weight measurements for Chinese adults aged between 20 and 74 years who lived in urban communities. From the 1998–2001 survey, 4,894 participants (2,081 men and 2,813 women, mean age: 48.9 years) were recruited, and 4,395 participants (1,599 men and 2,796 women, mean age: 49.8 years) were recruited from the 2007–2008 survey. Using the World Health Organization criteria, overweight was defined as 25 kg/m(2) ≤ BMI < 30 kg/m(2) and obesity as BMI ≥ 30 kg/m(2). Central obesity was defined as WC ≥ 90 cm in men or ≥85 cm in women. The differences in prevalence of obesity, central obesity and overweight between the two surveys were tested using multivariable logistic regression analyses. RESULTS: Compared to the 1998–2001 survey, in the 2007–2008 survey the BMI distribution for men and the WC distribution for both genders is shifted significantly to the right along the x-axis (all p < 0.001). Over the ten years, the prevalence of combined overweight and obesity increased 24% (from 31.5% to 39.1%, p < 0.001) in men, but decreased 8% (from 27.3% to 25.0%; p < 0.01) in women. The prevalence of central obesity increased 40% in men (from 19.5% to 27.3%; p < 0.01), but the increase was not significant in women (15.0% to 17.1%; p = 0.051). In the total population, only central obesity showed a significant change between the populations in the two surveys, increasing 29% (from 17.3% to 22.4%; p < 0.001). CONCLUSIONS: Over this 10 year period, central obesity increased significantly in the Shanghai adult population. However, the prevalence of combined overweight and obesity was significantly increased in men but not in women