89 research outputs found

    Cloning and characterization of two subunits of calcineurin cDNA in naked carp (Gymnocypris przewalskii) from Lake Qinghai, China

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    The naked carp (Gymnocypris przewalskii), a native teleost, plays an important role in maintenance of the ecological balance in the system of Lake Qinghai (altitude, 3.2 km) on the Qinghai-Tibet Plateau in China. Calcineurin (CN) is the only member of the serine/threonine phosphatase family that can be activated by both Ca2+ and calmodulin (CaM) and involved in many important physiological processes such as salt tolerance/adaption. In this report, cDNAs of CN catalytic subunit paralogue isoforms: GpCAα (GenBank accession no.JQ407043), GpCAγ (GenBank accession no. JQ407043), and CN regulatory subunit (GpCB) (GenBank accession no. JQ410473), were isolated from Gymnocypris przewalskii and their expression patterns in embryos developmentwere characterized. Gene expression profile demonstrated that GpCA and GpCB mRNA was distributed ubiquitously in all embryonic stages and showed decline until final stage of development. Immunohistologicalanalysis revealed CN localization in different tissues including kidney, heart, brain, spermary, and gill. Collectively, these results provide molecular basis and clues to further understand the role of CN during embryos development and its function in tissues for the adaptation mechanism of naked carp

    Evolutionary origin of genomic structural variations in domestic yaks

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    Yak has been subject to natural selection, human domestication and interspecific introgression during its evolution. However, genetic variants favored by each of these processes have not been distinguished previously. We constructed a graph-genome for 47 genomes of 7 cross-fertile bovine species. This allowed detection of 57,432 high-resolution structural variants (SVs) within and across the species, which were genotyped in 386 individuals. We distinguished the evolutionary origins of diverse SVs in domestic yaks by phylogenetic analyses. We further identified 334 genes overlapping with SVs in domestic yaks that bore potential signals of selection from wild yaks, plus an additional 686 genes introgressed from cattle. Nearly 90% of the domestic yaks were introgressed by cattle. Introgression of an SV spanning the KIT gene triggered the breeding of white domestic yaks. We validated a significant association of the selected stratified SVs with gene expression, which contributes to phenotypic variations. Our results highlight that SVs of different origins contribute to the phenotypic diversity of domestic yaks

    Allelic shift in cis-elements of the transcription factor RAP2.12 underlies adaptation associated with humidity in Arabidopsis thaliana

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    Populations of widespread species are usually geographically distributed through contrasting stresses, but underlying genetic mechanisms controlling this adaptation remain largely unknown. Here, we show that in Arabidopsis thaliana, allelic changes in the cis-regulatory elements, WT box and W box, in the promoter of a key transcription factor associated with oxygen sensing, RELATED TO AP 2.12 (RAP2.12), are responsible for differentially regulating tolerance to drought and flooding. These two cis-elements are regulated by different transcription factors that downstream of RAP2.12 results in differential accumulation of hypoxia-responsive transcripts. The evolution from one cis-element haplotype to the other is associated with the colonization of humid environments from arid habitats. This gene thus promotes both drought and flooding adaptation via an adaptive mechanism that diversifies its regulation through noncoding alleles

    Spatial inequity in access to healthcare facilities at a county level in a developing country: a case study of Deqing County, Zhejiang, China

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    Background The inequities in healthcare services between regions, urban and rural, age groups and diverse income groups have been growing rapidly in China. Equal access to basic medical and healthcare services has been recognized as “a basic right of the people” by Chinese government. Spatial accessibility to healthcare facilities has received huge attention in Chinese case studies but been less studied particularly at a county level due to limited availability of high-resolution spatial data. This study is focused on measuring spatial accessibility to healthcare facilities in Deqing County. The spatial inequity between the urban (town) and rural is assessed and three scenarios are designed and built to examine which scenario is instrumental for better reducing the spatial inequity. Methods This study utilizes highway network data, Digital Elevation Model (DEM), location of hospitals and clinics, 2010 census data at the finest level – village committee, residential building footprint and building height. Areal weighting method is used to disaggregate population data from village committee level to residential building cell level. Least cost path analysis is applied to calculate the travel time from each building cell to its closest healthcare facility. Then an integral accessibility will be calculated through weighting the travel time to the closest facility between three levels. The spatial inequity in healthcare accessibility between the town and rural areas is examined based on the coverages of areas and populations. The same method is used to compare three scenarios aimed at reducing such spatial inequity – relocation of hospitals, updates of weighting values, and the combination of both. Results 50.03 % of residents can reach a county hospital within 15 min by driving, 95.77 % and 100 % within 30 and 60 min respectively. 55.14 % of residents can reach a town hospital within 5 min, 98.04 % and 100 % within 15 and 30 min respectively. 57.86 % of residential building areas can reach a village clinic within 5 min, 92.65 % and 99.22 % within 10 and 15 min. After weighting the travel time between the three-level facilities, 30.87 % of residents can reach a facility within 5 min, 80.46 %% and 99.88 % within 15 and 30 min respectively. Conclusions The healthcare accessibility pattern of Deqing County has exhibited spatial inequity between the town and rural areas, with the best accessibility in the capital of the county and poorest in the West of the county. There is a high negative correlation between population ageing and healthcare accessibility. Allocation of more advanced medical and healthcare equipment and highly skillful doctors and nurses to village clinics will be an efficient means of reducing the spatial inequity and further consolidating the national medical security system. GIS (Geographical Information Systems) methods have proven successful method of providing quantitative evidence for policy analysis although the data sets and methods could be further improved

    Aridity-driven shift in biodiversity–soil multifunctionality relationships

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    From Springer Nature via Jisc Publications RouterHistory: received 2021-01-07, accepted 2021-08-12, registration 2021-08-25, pub-electronic 2021-09-09, online 2021-09-09, collection 2021-12Publication status: PublishedFunder: National Natural Science Foundation of China (National Science Foundation of China); doi: https://doi.org/10.13039/501100001809; Grant(s): 31770430Abstract: Relationships between biodiversity and multiple ecosystem functions (that is, ecosystem multifunctionality) are context-dependent. Both plant and soil microbial diversity have been reported to regulate ecosystem multifunctionality, but how their relative importance varies along environmental gradients remains poorly understood. Here, we relate plant and microbial diversity to soil multifunctionality across 130 dryland sites along a 4,000 km aridity gradient in northern China. Our results show a strong positive association between plant species richness and soil multifunctionality in less arid regions, whereas microbial diversity, in particular of fungi, is positively associated with multifunctionality in more arid regions. This shift in the relationships between plant or microbial diversity and soil multifunctionality occur at an aridity level of ∼0.8, the boundary between semiarid and arid climates, which is predicted to advance geographically ∼28% by the end of the current century. Our study highlights that biodiversity loss of plants and soil microorganisms may have especially strong consequences under low and high aridity conditions, respectively, which calls for climate-specific biodiversity conservation strategies to mitigate the effects of aridification

    Fault Investigation and Operation Strategy of Dry Type Air-core Reactor in Severe Cold Environment

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    The influence of extreme climate such as severe cold temperature on power transmission system can not be ignored, the low temperature could cause complicated mechanical and dielectric deterioration to electrical materials and devices. In China’s recent operation experience of reactors, it is found the burning fault rate of dry type air-core reactors in cold northeast region was obviously higher than that of other regions, which had inflicted negative impact on substation equipment and personnel safety. To tackle with the problems and prevent potential faults, typical fault characteristics and mechanism at low temperature, the specific influence of low temperature on materials and reactor performance, as well as corresponding operation strategies would be studied and proposed in this paper

    Freeze-thaw-assisted aqueous two-phase system as a green and low-cost option for analytical grade B-phycoerythrin production from unicellular microalgae Porphyridium purpureum

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    Microalgae are promising alternative sources for natural phycobiliprotein production since they grow rapidly and can be cultured on a large scale. However, the overall economic viability of analytical grade phycoerythrin production from microalgae is limited by the high cost of the pretreatment required to break down the cell wall, as well as the expensive reagents and equipment used during purification. This study developed a novel extraction and purification process to recovery B-phycoerythrin (B-PE) in a freeze-thaw-assisted aqueous two-phase system (FT-ATPS) from Porphyridium purpureum. The effects of culture strategy, extraction method and purification factors on B-PE production were studied systematically. The results revealed that low light induced B-PE synthesis, whereas hindered the growth. The stepwise light supplement strategy alleviated the growth limitation under low-light conditions and increased the final B-PE production, up to 182.1 +/- 4.1 mg/L (increasing by 73.1 %). Compared with the traditional electricity highly-consumed ultrasonication method, the green freeze-thaw method could extract B-PE without damaging the cell structure and save much more power (> 98 %), and the extraction rate reached the highest when frozen at -80 C. The purity and concentration of B -PE in crude extract were proved to have a significant effect on ATPS purification, and the higher the former, the better the latter. A total production cost of 0.045 $/mg (decreasing by 96.2 %) and purity of 5.6 +/- 0.2 (A(545)/A(280)) for analytical grade B-PE production were achieved by FT-ATPS based on 4 % polyethylene glycol (PEG2,000) and 20 % ammonium sulfate. Relative to the conventional method of phycoerythrin production, the method developed herein has greater safety, lower cost, and more environmental benefits, which can be function appropriately in the expensive purification of analytical grade phycobiliproteins

    Freeze-thaw-assisted aqueous two-phase system as a green and low-cost option for analytical grade B-phycoerythrin production from unicellular microalgae Porphyridium purpureum

    No full text
    Microalgae are promising alternative sources for natural phycobiliprotein production since they grow rapidly and can be cultured on a large scale. However, the overall economic viability of analytical grade phycoerythrin production from microalgae is limited by the high cost of the pretreatment required to break down the cell wall, as well as the expensive reagents and equipment used during purification. This study developed a novel extraction and purification process to recovery B-phycoerythrin (B-PE) in a freeze-thaw-assisted aqueous two-phase system (FT-ATPS) from Porphyridium purpureum. The effects of culture strategy, extraction method and purification factors on B-PE production were studied systematically. The results revealed that low light induced B-PE synthesis, whereas hindered the growth. The stepwise light supplement strategy alleviated the growth limitation under low-light conditions and increased the final B-PE production, up to 182.1 +/- 4.1 mg/L (increasing by 73.1 %). Compared with the traditional electricity highly-consumed ultrasonication method, the green freeze-thaw method could extract B-PE without damaging the cell structure and save much more power (> 98 %), and the extraction rate reached the highest when frozen at -80 C. The purity and concentration of B -PE in crude extract were proved to have a significant effect on ATPS purification, and the higher the former, the better the latter. A total production cost of 0.045 $/mg (decreasing by 96.2 %) and purity of 5.6 +/- 0.2 (A(545)/A(280)) for analytical grade B-PE production were achieved by FT-ATPS based on 4 % polyethylene glycol (PEG2,000) and 20 % ammonium sulfate. Relative to the conventional method of phycoerythrin production, the method developed herein has greater safety, lower cost, and more environmental benefits, which can be function appropriately in the expensive purification of analytical grade phycobiliproteins

    Lewis acid-mediated aqueous glycerol pretreatment of sugarcane bagasse: Pretreatment recycling, one-pot hydrolysis and lignin properties

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    Sugarcane bagasse was pretreated with Lewis acid-mediated glycerol, results showed that 98.47% glucan recovery, 95.31% xylan removal and 49.69% delignification were achieved by pretreatment using 80 wt% aqueous glycerol combined with 1.0 wt% AlCl3 at 150 degrees C for 1 h. Reutilization experiments of acidified glycerol showed that its pretreatment efficiency was relatively well maintained during four consecutive cycles. Enzymatic in situ saccharification of pretreated bagasse led to about 50% glucose yield at 16 wt% glycerol concentration. After pretreatment, the lignin distributed in pretreatment hydrolysate and pretreated solid residue (referred to as organosolv lignin (OL) and cellulolytic enzyme lignin (CEL), respectively) demonstrated contrasting effect on enzymatic hydrolysis with OL slightly increasing while CEL decreasing cellulose conversion, which could be explained by their differences in hydrophobicity and surface charge. Further analysis of the structure and molecular weights of two lignin samples indicated their great potential for valorization into value-added products. (C) 2021 Elsevier Ltd. All rights reserved

    An all-silicon design of a high-efficiency broadband transmissive terahertz polarization convertor

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    Abstract Polarization, a fundamental behavior of electromagnetic waves, holds immense potential across diverse domains such as environmental monitoring, biomedicine, and ocean exploration. However, achieving efficient modulation of terahertz waves with wide operational bandwidth poses significant challenges. Here, we introduce an all-silicon polarization converter designed specifically to operate in the terahertz range of the electromagnetic spectrum. Simulation results demonstrate that the average conversion efficiency of cross-linear waves exceeds 80% across a wide frequency range spanning from 1.00 to 2.32 THz, with the highest conversion efficiency peaking at an impressive 99.97%. Additionally, our proposed structure facilitates linear-to-circular polarization conversion with an ellipticity of 1 at 0.85 THz. Furthermore, by rotating the cross-shaped microstructure, active control over arbitrary polarization states can be achieved. To summarize, the proposed structure offers remarkable flexibility and ease of integration, providing a reliable and practical solution for achieving broadband and efficient polarization conversion of terahertz waves. Graphical abstrac
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