13 research outputs found
A Novel XOR-Based Threshold Visual Cryptography with Adjustable Pixel Expansion
A ( k , n ) visual cryptography (VC) scheme encodes a secret image into n shadows that are printed on transparencies distributed among a group of n participants secretly, and reveal the secret image by stacking no less than k of them. Its decryption requires no computation and attracts much attention in image security applications. The pixel expansion and contrast are two important characteristics to evaluate the visual quality of the revealed secret image for a ( k , n ) -VC scheme. The ( k , n ) XOR-based VC (XVC) schemes can greatly improve the visual quality including both pixel expansion and contrast. Previous methods require complex computation and result in high pixel expansion when they are used to construct such schemes. In this paper, we propose a pixel expansion adjustable ( k , n ) -XVC scheme, which allows pixel expansion to be changed among 2 k - 1 - 1 different values. It can ensure each pixel being exactly recovered with the same average contrast no matter it takes any pixel expansion value. The least pixel expansion is much smaller than previous schemes. Our scheme can be easily implemented based on any conventional OR-based ( k , n ) -VC (OVC) scheme
A Novel and Effective Recyclable BiOCl/BiOBr Photocatalysis for Lignin Removal from Pre-Hydrolysis Liquor
The presence of lignin hampers the utilization of hemicelluloses in the pre-hydrolysis liquor (PHL) from the kraft-based dissolving pulp production process. In this paper, a novel process for removing lignin from PHL was proposed by effectively recycling catalysts of BiOCl/BiOBr. During the whole process, BiOCl and BiOBr were not only adsorbents for removing lignin, but also photocatalysts for degrading lignin. The results showed that BiOCl and BiOBr treatments caused 36.3% and 33.9% lignin removal, respectively, at the optimized conditions, and the losses of hemicellulose-derived saccharides (HDS) were both 0.1%. The catalysts could be regenerated by simple photocatalytic treatment and obtain considerable CO and CO2. After 15 h of illumination, 49.9 μmol CO and 553.0 μmol CO2 were produced by BiOCl, and 38.7 μmol CO and 484.3 μmol CO2 were produced by BiOBr. Therefore, both BiOCl and BiOBr exhibit excellent adsorption and photocatalytic properties for lignin removal from pre-hydrolysis
Water resources and their management in Pakistan: A critical analysis on challenges and implications
Water is one of the essential natural resources for human beings. However, rising worldwide water demand and a significant decline in availability due to a lack of dynamic management and over-extraction have resulted in a complex scenario in terms of water availability. The current paper examines water resources and their management, methodologies, aims, and scope. Through the perspective of water resources and their management in Pakistan, 93 research publications were critically analyzed using a systematic review technique. The technique includes a systematic review of existing literature on water resource management, with particular emphasis on policy, governance, and environmental challenges. The study results demonstrate gaps and weaknesses in existing laws and regulations, alongside the threats to water resource management due to population expansion, urban development, climate change, and water contamination. To properly address these problems, the current study proposed a comprehensive framework for water resource management. This framework includes a national water policy that argues for sustainability and improves institutional strength. Infrastructure development, climate change adaptation, and examining social and environmental variables are all emphasized as important problems. Furthermore, it is essential to emphasize the importance of education and raising knowledge about water resource management among the general public and relevant stakeholders. By following these recommendations and the proposed OECD key principles on water governance, Pakistan may make significant progress towards achieving sustainable water management, aligning with its development objectives, and ensuring clean and safe water availability for future generations
An Optimised Region-Growing Algorithm for Extraction of the Loess Shoulder-Line from DEMs
The positive and negative terrains (P–N terrains) of the Loess Plateau of China are important geographical topography elements for measuring the degree of surface erosion and distinguishing the types of landforms. Loess shoulder-lines are an important terrain feature in the Loess Plateau and are often used as a criterion for distinguishing P–N terrains. The extraction of shoulder lines is important for predicting erosion and recognising a gully head. However, existing extraction algorithms for loess shoulder-lines in areas with insignificant slopes need to be improved. This study proposes a regional fusion (RF) method that integrates the slope variation-based method and region-growing algorithm to extract loess shoulder-lines based on a Digital Elevation Model (DEM) at a spatial resolution of 5 m. The RF method introduces different terrain factors into the growth standards of the region-growing algorithm to extract loess-shoulder lines. First, we employed a slope-variation-based method to build the initial set of loess shoulder-lines and used the difference between the smoothed and real DEMs to extract the initial set for the N terrain. Second, the region-growing algorithm with improved growth standards was used to generate a complete area of the candidate region of the loess shoulder-lines and the N terrain, which were fused to generate and integrate contours to eliminate the discontinuity. Finally, loess shoulder-lines were identified by detecting the edge of the integrated contour, with results exhibiting congregate points or spurs, eliminated via a hit-or-miss transform to optimise the final results. Validation of the experimental area of loess ridges and hills in Shaanxi Province showed that the accuracy of the RF method based on the Euclidean distance offset percentage within a 10-m deviation range reached 96.9% compared to the manual digitalisation method. Based on the mean absolute error and standard absolute deviation values, compared with Zhou’s improved snake model and the bidirectional DEM relief-shading methods, the proposed RF method extracted the loess shoulder-lines highly accurately
Chromosome-level genome assembly for takin (Budorcas taxicolor) provides insights into its taxonomic status and genetic diversity
The takin (Budorcas taxicolor) is one of the largest bovid herbivores in the subfamily Caprinae. The takin is at high risk of extinction, but its taxonomic status and genetic diversity remain unclear. In this study, we constructed the first reference genome of Bu. taxicolor using PacBio long High-Fidelity reads and Hi-C technology. The assembled genome is ~2.95 Gb with a contig N50 of 68.05 Mb, which were anchored onto 25+XY chromosomes. We found that the takin was more closely related to muskox than to other Caprinae species. Compared to the common ancestral karyotype of bovidae (2n = 60), we found the takin (2n = 52) experienced four chromosome fusions and one large translocation. Furthermore, we resequenced nine golden takins from the main distribution area, the Qinling Mountains, and identified 3.3 million single nucleotide polymorphisms. The genetic diversity of takin was very low (θπ = 0.00028 and heterozygosity =0.00038), among the lowest detected in domestic and wild mammals. Takin genomes showed a high inbreeding coefficient (FROH =0.217), suggesting severe inbreeding depression. The demographic history showed that the effective population size of takins declined significantly from ~100,000 years ago. Our results provide valuable information for protection of takins and insights into their evolution
New insights into the influence of encapsulation materials on the feasibility of ultrasonic-assisted encapsulation of Mosla chinensis essential oil
The study aimed to estimate the feasibility of α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD) to encapsulate Mosla chinensis essential oil (EO) by ultrasonic-assisted method. The physical properties variations, stabilization mechanisms, and formation processes of the inclusion complexes (ICs) were investigated using experimental methods, molecular docking, and molecular dynamics (MD) simulation. Scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis, and gas chromatography–mass spectrometry showed that the ICs were successfully prepared, which differentially improved the thermal stability and retained the chemical composition of EO. The dissolution profile showed that the Peppas model can be used to describe the diffuse release mechanism of EO. Finally, molecular docking and MD simulation theoretically confirmed the interaction and conformational changes of carvacrol (the main active component of Mosla chinensis EO) inside the cavity of CDs. The results indicate that hydrogen bonding was the primary driving force for the carvacrol spontaneous access to the cavity. Further, a binding dynamic balance occurs between carvacrol and β-CD, whereas a bind and away dynamic balance occurs in the IC between carvacrol and α-CD, γ-CD. The comprehensive results show that the medium cavity size of β-CD is a suitable host molecule for Mosla chinensis EO of encapsulation, release, and stabilization. A combination of experimental and theoretical calculations is useful for the pinpoint targeted design and optimization of CD molecular encapsulation of small entity molecules. β-CD was rationally screened as a better candidate for stabilizing EO, which provides an option for a meaningful path to realistic EO applications
A machine-learning approach clarifies interactions between contaminants of emerging concern
11 pages, 5 figures, supplemental information https://doi.org/10.1016/j.oneear.2022.10.006.-- Data and code availability: The raw data supporting the findings of this study are publicly available on GitHub: https://github.com/chenjian-research/mixture-risk-of-CECs. All analyses were performed using the open-source platform R v.4.0.4 and MATLAB R2019b. All scripts for modeling are publicly available on GitHub: https://github.com/chenjian-research/mixture-risk-of-CECsHumans and biotas are exposed to a cocktail of contaminants of emerging concern (CECs), but mixture regulation is lagging behind. This is largely attributed to inadequate experimental data of mixture risk; revealing intricate interactions among CECs in mixtures with random combinations remains a formidable challenge. Here, we propose a new framework comprised of 5,720 lab tests of mixture risk for 100 CECs with random combinations, extended prediction of mixture risk in any CEC combination via a new machine learning model, and validation in field sites. We identify a general concave-down relationship between CEC number and ecological risk of algae, invertebrates, and fish under different lab conditions and in more than 900 field sites worldwide. We propose a new “redundancy mechanism” to clarify interactions among CECs, suggesting implications in grouping CECs by action mode for developing mixture regulatory frameworks. Our framework provides a blueprint for addressing cocktail effects of multi-factors with random combinations in different disciplinesWith the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe
Sub-micron microparticles with tunable fluorescence emission obtained via co-self-assembly of amidoximed polymeric ligands and lanthanide ions
Lanthanide coordinating polymeric microparticles have witnessed increasing research interests during the past decades due to their versatile morphology and tunable fluorescent properties. Herein, we have synthesized an amidoximed block copolymer containing aromatic backbone and pendent amidoxime as well as carboxyl groups, which has been employed as the ligand to sensitize the intrinsic fluorescence emission of lanthanide ions of Tb3+ and Eu3+. Furthermore, the lanthanide coordinating polymeric microparticles showing tunable green and red emission fluorescence have been prepared via the emulsion confinement co-self-assembly of amidoximed polymeric ligands with Tb3+ and Eu3+. It is found that both the fluorescence emission and sizes of obtained fluorescent microparticles can be easily modulated in a wide range by tuning concentration of polymers and lanthanide ions, as well as emulsion evaporation temperature. Thanks to their tunable sizes (250–900 nm), fluorescence emission as well as presence of surface active functional groups, the present fluorescent microparticles would find potential applications in in-vitro detection, optical encoding and devices
Illegitimate Recombination between Duplicated Genes Generated from Recursive Polyploidizations Accelerated the Divergence of the Genus Arachis
The peanut (Arachis hypogaea L.) is the leading oil and food crop among the legume family. Extensive duplicate gene pairs generated from recursive polyploidizations with high sequence similarity could result from gene conversion, caused by illegitimate DNA recombination. Here, through synteny-based comparisons of two diploid and three tetraploid peanut genomes, we identified the duplicated genes generated from legume common tetraploidy (LCT) and peanut recent allo-tetraploidy (PRT) within genomes. In each peanut genome (or subgenomes), we inferred that 6.8–13.1% of LCT-related and 11.3–16.5% of PRT-related duplicates were affected by gene conversion, in which the LCT-related duplicates were the most affected by partial gene conversion, whereas the PRT-related duplicates were the most affected by whole gene conversion. Notably, we observed the conversion between duplicates as the long-lasting contribution of polyploidizations accelerated the divergence of different Arachis genomes. Moreover, we found that the converted duplicates are unevenly distributed across the chromosomes and are more often near the ends of the chromosomes in each genome. We also confirmed that well-preserved homoeologous chromosome regions may facilitate duplicates’ conversion. In addition, we found that these biological functions contain a higher number of preferentially converted genes, such as catalytic activity-related genes. We identified specific domains that are involved in converted genes, implying that conversions are associated with important traits of peanut growth and development
Conversion between 100-million-year-old duplicated genes contributes to rice subspecies divergence
Abstract Background Duplicated gene pairs produced by ancient polyploidy maintain high sequence similarity over a long period of time and may result from illegitimate recombination between homeologous chromosomes. The genomes of Asian cultivated rice Oryza sativa ssp. indica (XI) and Oryza sativa ssp. japonica (GJ) have recently been updated, providing new opportunities for investigating ongoing gene conversion events and their impact on genome evolution. Results Using comparative genomics and phylogenetic analyses, we evaluated gene conversion rates between duplicated genes produced by polyploidization 100 million years ago (mya) in GJ and XI. At least 5.19–5.77% of genes duplicated across the three rice genomes were affected by whole-gene conversion after the divergence of GJ and XI at ~ 0.4 mya, with more (7.77–9.53%) showing conversion of only portions of genes. Independently converted duplicates surviving in the genomes of different subspecies often use the same donor genes. The ongoing gene conversion frequency was higher near chromosome termini, with a single pair of homoeologous chromosomes, 11 and 12, in each rice genome being most affected. Notably, ongoing gene conversion has maintained similarity between very ancient duplicates, provided opportunities for further gene conversion, and accelerated rice divergence. Chromosome rearrangements after polyploidization are associated with ongoing gene conversion events, and they directly restrict recombination and inhibit duplicated gene conversion between homeologous regions. Furthermore, we found that the converted genes tended to have more similar expression patterns than nonconverted duplicates. Gene conversion affects biological functions associated with multiple genes, such as catalytic activity, implying opportunities for interaction among members of large gene families, such as NBS-LRR disease-resistance genes, contributing to the occurrence of the gene conversion. Conclusion Duplicated genes in rice subspecies generated by grass polyploidization ~ 100 mya remain affected by gene conversion at high frequency, with important implications for the divergence of rice subspecies