|Metacognition refers to the ability to introspect our cognitive ability, which plays an essential role in guiding and optimizing our activities. However, little is known about metacognitive capacity for highly practiced motor behaviors and its neural correlates. Using structural and functional magnetic resonance imaging (MRI), the present study examined the brain substrates underlying individual differences in self-awareness of handwriting in adults, a highly practiced visuomotor skill. Results showed that adult writers generally overestimate their handwriting skill, which is more pronounced in males relative to females. The extent of overestimation of handwriting quality was positively correlated with grey matter volume in the left fusiform gyrus, right middle frontal gyrus and right precuneus. Moreover, the activation of these regions in a handwriting task was not correlation with self-awareness of handwriting, confirming that the identified connection between brain structures and handwriting self-awareness is independent of task performances. The left fusiform gyrus and right middle frontal gyrus are thought to represent domain-specific brain mechanisms for handwriting self-awareness, while the right precuneus is likely to be a domain-general brain mechanism, suggesting that the ability of introspect practiced visuomotor skills relies on both domain-general and domain-specific brain systems. Together, this study is the first to reveal the neuroanatomical correlates of a highly practiced motor behavior, extending our understanding about the neural basis of human metacognition.|
|This study aimed to examine the brain mechanisms underlying the distinctions between automatic and controlled handwriting. Functional magnetic resonance imaging data were collected while adult participants (n = 53) performed a copying task with varying speed control demands. Network analysis showed significant differences in functional connectivity within and between the frontoparietal network (FPN), the default mode network (DMN), the dorsal attention network (DAN), the somatomotor network (SMN) and the visual network (VN) between automatic and speed-controlled handwriting irrespective of written materials, which are thought to reflect general executive control and task-relevant visuomotor operations. However, there were no differences in brain activation between automatic and controlled handwriting. These results suggest that reconfiguration of functional network architecture, rather than regional activation, underlies the dissociations between automatic and controlled handwriting. Our findings shed new light on the neural mechanisms of handwriting mastery and handwriting impairments in individuals with neurological disorders.|
|新型冠状病毒（2019-nCoV）自2019年12月在湖北省武汉市爆发，并迅速传播到中国多地及其他国家。在本研究中，我们报告了来自中国深圳早期的2019-nCoV感染患者的流行病学、临床指标、生化指标和影像学特征，以及可用于预测疾病严重程度的潜在生物标记物。所有12例2019-nCoV感染的肺炎患者均发展为肺炎，其中一半患者进一步发展为急性呼吸窘迫综合征（acute respiratory distress syndrome，ARDS）。最常见的实验室检测生化指标异常是低白蛋白（albumine，ALB）血症、淋巴细胞（lymphocytes，LYM）计数减少，淋巴细胞百分比和中性粒细胞（neutrophils，NEU）百分比降低，C反应蛋白（C-reactive protein，CRP）和乳酸脱氢酶（lactate dehydrogenase，LDH）水平升高，以及CD8细胞计数降低。从患者呼吸道特别是下呼吸道检测到的2019-nCoV病毒滴度与肺部疾病的严重程度正相关。 ALB、LYM、LYM（%）、LDH、NEU（％）和CRP的水平与急性肺损伤程度高度相关。年龄、病毒滴度、肺损伤评分和血液生化指标：ALB、CRP、LDH、LYM（%）、LYM和NEU（%）可能是疾病严重程度的预测指标。此外， 2019-nCoV感染患者的血浆血管紧张素II水平显着升高，并且与病毒滴度和肺损伤程度线性相关。我们的研究结果提供了多种潜在的可用于诊断的生物标志物， 并提出了血管紧张素 II受体阻滞剂（angiotensin II receptor blocker，ARB）药物或可作为治疗2019-nCoV感染的潜在药物进行深入研究。|
Effects of sludge utilization on the mobility and phytoavailability of heavy metals in soil-plant systems have attracted broad attention in recent years. In this study, we analyzed the effects of municipal sludge compost (MSC) on the solubility and plant uptake of Cd, Ni, Cu, Zn and Pb in a soil-potato system to explore the mobility, potato plant uptake and enrichment of these five heavy metals in sierozem soils amended with MSC through a potato cultivation trial in Lanzhou University of China in 2014. Ridge regression analysis was conducted to investigate the phytoavailability of heavy metals in amended soils. Furthermore, CaCl2, CH3COONH4, CH3COOH, diethylene triamine pentacetic acid (DTPA) and ethylene diamine tetraacetic acid (EDTA) were used to extract the labile fraction of heavy metals from the amended soils. The results show that the MSC could not only improve the fertility but also increase the dissolved organic carbon (DOC) content of sierozem soils. The total concentrations and labile fraction proportions of heavy metals increase with increasing MSC percentage in sierozem soils. In amended soils, Cd has the highest solubility and mobility while Ni has the lowest solubility and mobility among the five heavy metals. The MSC increases the concentrations of heavy metals in the root, stem, peel and tuber of the potato plant, with the concentrations being much higher in the stem and root than in the peel and tuber. Among the five heavy metals, the bioconcentration factor value of Cd is the highest, while that of Ni is the lowest. The complexing agent (DTPA and EDTA) extractable fractions of heavy metals are the highest in terms of phytoavailability. Soil properties (including organic matter, pH and DOC) have important impacts on the phytoavailability of heavy metals. Our results suggest that in soil-potato systems, although the MSC may improve soil fertility, it can also increase the risk of soils exposed to heavy metals.
|The high frequency vibration analysis of a composite laminate plate structure subjected to impact loads was investigated by using method of energy finite element analysis (EFEA). The time and space averaged energy density was used as the primary variable to form the governing differential equations. The multilayer laminate plate is simplified to be equivalent isotropic plate using the average concept, such as the average damping loss factor and the average group speed. The global system of EFEA equations can be solved numerically and the energy density distribution within the whole system can then be obtained. The EFEA numerical results for composite laminate plate structure are validated through comparison with those of very dense conventional finite element analysis (FEA).|
|Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed 4150 km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated accel- eration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days.|
|Norovirus (NoV) causes epidemic acute gastroenteritis in humans, whereby histo-blood group antigens (HBGAs) play an important role in host susceptibility. Each of the two major genogroups (GI and GII) of human NoVs recognizes a unique set of HBGAs through a distinct binding interface that is conserved within a genogroup, indicating a distinct evolutionary path for each genogroup. Here, we characterize a Lewis a (Le(a)) antigen binding strain (OIF virus) in the GII. 21 genotype that does not share the conserved GII binding interface, revealing a new evolution lineage with a distinct HBGA binding interface. Sequence alignment showed that the major residues contributing to the new HBGA binding interface are conserved among most members of the GII. 21, as well as a closely related GII. 13 genotype. In addition, we found that glycerol inhibits OIF binding to HBGAs, potentially allowing production of cheap antivirals against human NoVs. Taken together, our results reveal a new evolutionary lineage of NoVs selected by HBGAs, a finding that is important for understanding the diversity and widespread nature of NoVs.|
In Arabidopsis thaliana and Oryza sativa, the cytochrome P450 (CYP) 714 protein family represents a unique group of CYP monooxygenase, which functions as a shoot-specific regulator in plant development through gibberellin deactivation. Here, we report the functional characterizations of PtCYP714A3, an OsCYP714D1/Eui homologue from Populus trichocarpa. PtCYP714A3 was ubiquitously expressed with the highest transcript level in cambium–phloem tissues, and was greatly induced by salt and osmotic stress in poplar. Subcellular localization analyses indicated that PtCYP714A3-YFP fusion protein was targeted to endoplasmic reticulum (ER). Expression of PtCYP714A3 in the rice eui mutant could rescue its excessive-shoot-growth phenotype. Ectopic expression of PtCYP714A3 in rice led to semi-dwarfed phenotype with promoted tillering and reduced seed size. Transgenic lines which showed significant expression of PtCYP714A3 also accumulated lower GA level than did the wild-type (WT) plants. The expression of some GA biosynthesis genes was significantly suppressed in these transgenic plants. Furthermore, transgenic rice plants exhibited enhanced tolerance to salt and maintained more Na+ in both shoot and root tissues under salinity stress. All these results not only suggest a crucial role of PtCYP714A3 in shoot responses to salt toxicity in rice, but also provide a molecular basis for genetic engineering of salt-tolerant crops.