842 research outputs found
The role of environmental factors in the spatial distribution of Japanese encephalitis in mainland China
No full textAbstract not availableLiya Wang, Wenbiao Hu, Ricardo J. Soares Magalhaes, Peng Bi, Fan Ding, Hailong Sun, Shenlong Li, Wenwu Yin, Lan Wei, Qiyong Liu, Ubydul Haque, Yansong Sun, Liuyu Huang, Shilu Tong, Archie C.A. Clements, Wenyi Zhang, Chengyi L
Energy storage in Chlamydomonas reinhardtii measured with photoacoustic techniques
No full textThe energy storage efficiencies of the reaction centers in the intact cells of Chlamydomonas reinhardtii wild type cell, PSI-less mutants and PSII-less mutants in microsecond time window were determined using pulsed, time-resolved photoacoustic techniques. The heat emission from the photochemical reaction can result in the positive thermal expansion photoacoustic signal, opposing the negative thylokoid volume contraction signal caused by electrostriction during the charge separation. In this present research, we observed that PSI differed strongly from PSII, both in thermal expansion and volume contraction. Similar to the bacterial reaction centre, PSI is marked with the large volume contraction but small thermal expansion, in contrast to the large thermal expansion but small volume contraction in PSII. For wild type, the volume contraction signal is dominant over the thermal expansion signal upon low pulse energy illumination at room temperature. In microsecond time scale, the energy storage efficiencies were estimated to be 36%, 80±5%, and 50±14% per trap in wild type, PSI and PSII, respectively. The different energy conversion efficiencies are probably attributed to the escape of the bound counterions from the particle surface in PSI and rapid electron transfer in PSII. In the present work, we conducted the photoacoustic experiments to study the energy storage in different photosystem with the intact cells of PSI-less and PSII-less mutants, instead of using either specific wavelength excitation light or PSII inhibitors (e. g. DCMU), which were commonly applied in the previous studies. We also proved photoacoustic techniques’ usefulness and convenience in the photosynthesis research, especially in electron transfer and some related thermodynamics studies.M.S.Includes bibliographical references (p. 22-27)by Chengyi Ya
CaCO3 recrystallization in saline and alkaline soils
No full textAre desert ecosystems a stable sink for atmospheric CO2? Although the uptake of atmospheric CO2 by soil during the nighttime is detected in deserts and some semi-deserts, the underlying mechanisms remain elusive. In order to determine the factors affecting the CO2 fluxes into soil and to reveal the relationship between CO2 fluxes and carbonate formation and recrystallization in saline and alkaline soils, four soils with contrasting salinity from two sites, Aksu and Yingbazar, along the Tarim River were analysed. Soils were incubated in (CO2)-C-14 labelled atmosphere for 90 days at three CO2 concentrations: 0.04%, 0.4% and 4%. The C-14 activity was measured in soil water and air, as well as in carbonates after 2,14 and 90 days. The C-14 incorporation in CaCO3 increased with corresponding C-14 decrease remaining in the CO2. The highest C-14 incorporation into CaCO3 (54%) was observed in the Yingbazar saline soil. The carbonate recrystallization rates increased logarithmically (r(2) > 0.97) with the CO2 concentration. The average carbonate recrystallization rate from three sampling times was highest in the Yingbazar saline soil under 4% CO2 (8.45 x 10-6 day(-1)) and lowest in the Aksu alkaline soil under 0.04% CO2 (0.03 x 10(-6) day(-1)). The average carbonate recrystallization rate increased with electric conductivity (corresponding to soil salinity) but decreased with pH (R-2 = 0.99 for 4% CO2). The alkaline soils incorporated less C-14 into CaCO3 than the saline soils. At the highest CO2 concentration of 4%, the full recrystallization period of the remaining primary carbonates was 10- to 100-fold shorter than at the lower CO2 concentrations. Therefore, besides soil chemical parameters (e.g. pH, CaCO3 content), CO2 concentration (respiration of microorganisms and roots) is an important factor for CaCO3 recrystallization and formation of pedogenic carbonates in desert soils. It is the most important factor for CaCO3 recrystallization and so, for the formation of pedogenic carbonates. (C) 2016 Elsevier B.V. All rights reserved
sj-docx-1-pie-10.1177_09544089231163377 - Supplemental material for Fault diagnosis of reciprocating compressor based on the prediction of comprehensive index extracted from the expansion process in indicator diagram
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089231163377 for Fault diagnosis of reciprocating compressor based on the prediction of comprehensive index extracted from the expansion process in indicator diagram by Weifeng Wu, Chengyi Li, Jing Zhang, Yin Zhang, Xiaoran Li, Yifan Yang, Zhongqing Zhu and Bingsheng Wang in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
SINE jumping contributes to large-scale polymorphisms in the pig genomes
No full textAbstract Background Molecular markers based on retrotransposon insertion polymorphisms (RIPs) have been developed and are widely used in plants and animals. Short interspersed nuclear elements (SINEs) exert wide impacts on gene activity and even on phenotypes. However, SINE RIP profiles in livestock remain largely unknown, and not be revealed in pigs. Results Our data revealed that SINEA1 displayed the most polymorphic insertions (22.5 % intragenic and 26.5 % intergenic), followed by SINEA2 (10.5 % intragenic and 9 % intergenic) and SINEA3 (12.5 % intragenic and 5.0 % intergenic). We developed a genome-wide SINE RIP mining protocol and obtained a large number of SINE RIPs (36,284), with over 80 % accuracy and an even distribution in chromosomes (14.5/Mb), and 74.34 % of SINE RIPs generated by SINEA1 element. Over 65 % of pig SINE RIPs overlap with genes, most of them (> 95 %) are in introns. Overall, about one forth (23.09 %) of the total genes contain SINE RIPs. Significant biases of SINE RIPs in the transcripts of protein coding genes were observed. Nearly half of the RIPs are common in these pig breeds. Sixteen SINE RIPs were applied for population genetic analysis in 23 pig breeds, the phylogeny tree and cluster analysis were generally consistent with the geographical distributions of native pig breeds in China. Conclusions Our analysis revealed that SINEA1–3 elements, particularly SINEA1, are high polymorphic across different pig breeds, and generate large-scale structural variations in the pig genomes. And over 35,000 SINE RIP markers were obtained. These data indicate that young SINE elements play important roles in creating new genetic variations and shaping the evolution of pig genome, and also provide strong evidences to support the great potential of SINE RIPs as genetic markers, which can be used for population genetic analysis and quantitative trait locus (QTL) mapping in pig
Bio-inspired self-assembly of waxberry-like core-shell SiO2@TiO2 nanoparticles towards antiglare coatings
No full textWaxberry-like core-shell SiO2@TiO2 nanoparticles were prepared by liquid-phase deposition (LPD) method. The dip-coating self-assembly of waxberry-like core-shell SiO2@TiO2 nanoparticles has been used to fabricate coatings with excellent antiglare properties in the large angle and wide wavelength range. The field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements showed that the surface of SiO2 nanoparticles were coated by titania as a shell with controllable and uniform thickness. The ultraviolet visible near-infrared spectrophotometer (UV-Vis-NIR) results indicate that the maximum transmittance of the antiglare coating is up to 95.80% in the visible band, whereas that of the pure glass substrate is only 92.10%. The scattering and haze of the films have been measured to show that such specifically structured coatings exhibited good antiglare properties in the large angle and wide wavelength range
Computer‐based scaffoldings influence students\u27 metacognitive monitoring and problem‐solving efficiency in an intelligent tutoring system
No full textBackground Computer‐based scaffolding has been intensively used to facilitate students\u27 self‐regulated learning (SRL). However, most previous studies investigated how computer‐based scaffoldings affected the cognitive aspect of SRL, such as knowledge gains and understanding levels. In contrast, more evidence is needed to examine the effects of scaffolding on the metacognitive dimension and efficiency outcome of SRL. Objectives This study aims to examine the role of computer‐based scaffolding in students\u27 metacognitive monitoring and problem‐solving efficiency. Methods Seventy‐two medical students completed two clinical reasoning tasks in BioWorld, an intelligent tutoring system (ITS) designed for promoting medical students\u27 diagnostic expertise. During solving the tasks, students were asked to report their confidence judgements about proposed diagnoses. Computer trace data were used to identify task completion time (CT) and students\u27 use of three scaffolding types, that is, conceptual, strategic, and metacognitive. Then we calculated students\u27 metacognitive monitoring accuracy (i.e., calibration) and problem‐solving efficiency. Results and Conclusions One‐sample t ‐test demonstrated that students inaccurately monitored their learning processes and were overconfident in both tasks. Linear mixed‐effects models (LMMs) indicated that the intensive use of metacognitive scaffolding positively predicted students\u27 metacognitive monitoring accuracy. Moreover, strategic scaffolding was negatively related to problem‐solving efficiency, whereas metacognitive scaffolding positively influenced problem‐solving efficiency. Takeaways This study shows the importance of metacognitive scaffolding in improving the accuracy of metacognitive monitoring and problem‐solving efficiency. Findings from this study provide new insights for instructors and ITS developers to optimise the design of scaffoldings. , Lay Description What is already known about this topic? Computer‐based scaffolding can facilitate students\u27 knowledge gains and academic performance during self‐regulated learning (SRL). The effects of computer‐based scaffolding on the metacognitive dimension and efficiency outcome of SRL are still in a nascent phase. What this paper adds? This paper explores how different types of computer‐based scaffolding affect students\u27 metacognitive monitoring and problem‐solving efficiency. Metacognitive scaffolding improved the accuracy of medical students\u27 confidence judgements. Metacognitive scaffolding promoted medical students\u27 diagnostic problem‐solving efficiency. Strategic scaffolding had a negative effect on problem‐solving efficiency. Implications for practice Instructors could provide more metacognitive scaffoldings to facilitate students\u27 metacognitive monitoring accuracy. The designers of intelligent tutoring systems and instructors should consider the costs associated with using scaffoldings
Two Retrotransposon Elements in Intron of Porcine BMPR1B Is Associated with Phenotypic Variation
No full textIt has been established that through binding to bone morphogenetic proteins (BMPs), bone morphogenetic protein receptor I B (BMPR1B) can mediate transforming growth factor β (TGF-β) signal transduction, and is involved in the regulation of several biological processes, such as bone and muscle formation and homeostasis, as well as folliculogenesis. Also known as FecB, BMPR1B has been reported as the major gene for sheep prolificacy. A number of previous studies have analyzed the relationship between single nucleotide polymorphisms (SNPs) in this gene and its related performance. In recent years, with the illustration of the effect of retrotransposon insertion on the expression of the proximal genes or phenotypic variation, retrotransposon insertion polymorphisms (RIPs) have been used as a novel type of molecular marker in the evaluation of evolution, population structure and breeding of plant and domestic animals. In this study, the RIPs in porcine BMPR1B gene were excavated, and thereafter verified using a comparative genome and polymerase chain reaction (PCR). The potential effects of phenotype, gene expression and functions related to RIPs were also explored. The results showed that 13 distinct RIPs were identified in introns of porcine BMPR1B. Among these, only BMPR1B-SINE-RIP9 and BMPR1B-LINE-RIP13 displayed a close relationship with the growth traits of Large White pigs. Moreover, the total number of BMPR1B-SINE+/+-RIP9 individuals born was found to be significantly higher than that of SINE−/− (p < 0.05). These two RIPs showed an obvious distribution pattern among Chinese indigenous breeds and Western commercial breeds. The expression of BMPR1B in ovaries of adult BMPR1B-SINE+/+-RIP9 Sushan pigs was found to be significantly higher in comparison to those of BMPR1B-SINE−/−-RIP9 (p < 0.05). SINE insertion of BMPR1B-SINE-RIP9 and LINE insertion of BMPR1B-LINE-RIP13 were observed to significantly increase the activity of Octamer binding transcription factor 4 (OCT4) minipromoter in CHO and C2C12 cells (p < 0.01). Therefore, these two RIPs could serve as useful molecular markers for modulating the growth or reproductive traits in assisted selection of pig breeding, while the mechanisms of the insertion function should be studied further
Analysis of impact factors on scrubland soil respiration in the southern Gurbantunggut Desert, central Asia
No full textMonitoring soil CO2 respiration with chamber measurements and identifying controlling factors such as the diversity of vegetation species, moisture and temperature can help guide desert scrubland management. Soil CO2 respiration and potential controlling factors at four sites in desert scrubland were examined along the Sangong River Basin (SRB) in northwestern China in 2004. Soil CO2 respiration descended along the SRB as did the diversity of vegetation species, air temperature and air humidity. The two sites of the field station (FS) and the north desert (ND) and the low reaches of the SRB among these locations were monitored to analyze the effects of pH value, soil organic carbon (SOC), total nitrogen (TN) and calcium carbonate (CaCO3) on soil CO2 respiration during the growing season in 2005. The ND site was located at the southern edge of the Gurbantunggut Desert; the FS site was in the border area of the SRB Alluvial Fan. One-way ANOVA was performed. The result showed that air humidity and CaCO3 content had a strong influence on soil CO2 respiration; SOC content was a limitation to soil CO2 respiration in the arid-desert zone. Effective management activities can attenuate soil CO2 respiration and keep carbon balance trends at a desirabe level in desert scrublands
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