In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tes...In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.展开更多
Distinctness, Uniformity and Stability (DUS) testing is the technical base of Plant Variety Protection (PVP) and the scientific basis for the approval of Plant Breeder's Rights (PBR). DUS Test Guidelines are no...Distinctness, Uniformity and Stability (DUS) testing is the technical base of Plant Variety Protection (PVP) and the scientific basis for the approval of Plant Breeder's Rights (PBR). DUS Test Guidelines are not only the technical manuals for the DUS testing authorities to conduct the testing, but also the technical standards for the competent authorities to examine the DUS of new varieties of plants. Tea plant, originated from Yunnan Province, China, is a very important woody cash species in the world. The International Union for the Protection of New Varieties of Plants (UPOV) DUS Test Guidelines for tea plant is the first Test Guidelines prepared by China for the UPOV. In this article, the subject, selection, and determination of characteristics, states of expression of characteristics and the selection of example varieties, assessment of the UPOV DUS Test Guidelines for tea plant were elucidated in detail. Finally, the proposal of PVP for tea plant in China was also proposed. The preparation of UPOV DUS Test Guidelines for tea plant will have important significance both for promoting the development of PVP and increasing the status of international PVP fields for China.展开更多
Assessment of variety distinctness is important for both the registration and the protection of particular variety. However, the current testing system, which assesses a range of morphological characters of each pair ...Assessment of variety distinctness is important for both the registration and the protection of particular variety. However, the current testing system, which assesses a range of morphological characters of each pair of varieties grown side-by-side, is time-consuming and is not suitable for the assessment of hundreds of samples. The objective of this study was to develop a procedure for the assessment of wheat variety distinctness using simple sequence repeat(SSR) markers. A comparison between the molecular and morphological profile of 797 varieties was made. On the basis of the comparison, pairs of varieties with a genetic similarity value(GSV) ≤90% were deemed to be distinct, accounting for ~85% of varieties assessed in wheat regional trials. For the remaining ~15% of varieties, GSVs between different varieties were 〉90%, among which ~35% were not distinct and the other ~65% were distinct. Therefore, if given a GSV〉90%, the pairs of varieties should be morphologically assessed in the field. To avoid any errors in the assessments, we proposed the elimination of contaminant plants from the sample before comparing the varietal genotypes, scoring of the genotype at each locus with a pair of allele numbers when constructing a molecular profile, and faithfully recording two alleles at a non-homozygous locus. To reduce the workload and cost, a three-grade markers comparison among varieties is suggested. In addition, 80 SSR markers and a technical procedure for assessment of wheat variety distinctness have been proposed. Based on the procedure, the distinctness assessment of ~85% of all wheat varieties is completed in our laboratory annually. Consequently, total field assessment has been reduced considerably.展开更多
The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerpr...The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerprinting the lettuce cultivars. Fifty-eight EST-SSR markers showed hy-per-variability and were able to differentiate 92 cultivars. A total of 176 polymorphic amplified fragments were obtained by the 58 markers, and two to eight SSR alleles were detected for each l°Cus with an average of three alleles per locus. Average polymorphism information content (PIC) was 0.425, ranging from 0.022 to 0.743. Cluster analysis was based on Jaccard’s distance coefficients using the method of unweighted pair group. In this method we used arithmetical averages (UPGMA) algorithm categorized 4 major groups, which were in accordance to morphological traits. The eight cultivars of three groups with 100% genetic similarity through SSR analysis were investigated by phenotypic traits. These cultivars including these pairs are very similar in 27 morphological characteristics. Therefore, these EST-SSR markers could be used to select similar cultivars through management of reference collection to complement distinctiveness test of lettuce cultivars.展开更多
The intertidal zone is a complex coastal area exposed to a wide variety of environmental factors. During low tide, rocky pools are exposed to air for several hours throughout the day, and environmental conditions such...The intertidal zone is a complex coastal area exposed to a wide variety of environmental factors. During low tide, rocky pools are exposed to air for several hours throughout the day, and environmental conditions such as temperature and salinity are highly variable. Fish communities that inhabit these tide pools are also exposed to environmental variability;therefore it is important to look at fish community structure in relation to important environmental factors such as temperature, salinity and dissolved oxygen on tide pools during spring tides, time of greater exposure to air. Therefore, the aim of the present study was to analyze the variation of the taxonomic distinctness of intertidal fish communities considering temperature, salinity and dissolved oxygen of the water that remains trapped in the tide pools during low tide. Visual census surveys were carried out monthly, from January to December 2015, in the intertidal zone of El Faro during spring tides on full moon days, when fluctuations of environmental variables are significant. Total extension of the census surveys was 156 × 5 m (780 m2). A total of 145 tide pools were sampled and divided in three groups (small, medium and large) according to size and depths that ranged from 20 to 45 cm. Temperature, salinity and dissolved oxygen fluctuate throughout the year of study. Thermal difference between open ocean and tide pools ranged from 3.5°C to 4.5°C. A total of 3757 organisms from 22 species, 12 families, four orders and one class were recorded. When comparing taxonomic distinctness and average taxonomic distinctness between months and tide pools of different sizes, values fell within the confidence intervals in the tunnel and were located close to the mean.展开更多
The problem of identifying differential activity such as in gene expression is a major defeat in biostatistics and bioinformatics. Equally important, however much less frequently studied, is the question of similar ac...The problem of identifying differential activity such as in gene expression is a major defeat in biostatistics and bioinformatics. Equally important, however much less frequently studied, is the question of similar activity from one biological condition to another. The fold- change, or ratio, is usually considered a relevant criterion for stating difference and similarity between measurements. Importantly, no statistical method for concomitant evaluation of similarity and distinctness currently exists for biological applications. Modern micro- array, digital PCR (dPCR), and Next-Generation Sequencing (NGS) technologies frequently provide a means of coeff^cient of variation estimation for individual measurements. Using fold-change, and by making the assumption that measurements are normally distributed with known variances, we designed a novel statistical test that allows us to detect concomitantly, thus using the same formalism, differ- entially and similarly expressed genes (http:]]cds.ihes.fr). Given two sets of gene measurements in different biological conditions, the probabilities of making type I and type II errors in stating that a gene is differentially or similarly expressed from one condition to the other can be calculated. Furthermore, a confidence interval for the fold-change can be delineated. Finally, we demonstrate that the assumption of normality can be relaxed to consider arbitrary distributions numerically. The Concomitant evaluation of Distinctness and Similarity (CDS) statistical test correctly estimates similarities and differences between measurements of gene expression. The imple- mentation, being time and memory efficient, allows the use of the CDS test in high-throughput data analysis such as microarray, dPCR, and NGS experiments. Importantly, the CDS test can be applied to the comparison of single measurements (N = 1) provided the var- iance (or coefficient of variation) of the signals is known, making CDS a valuable tool also in biomedical analysis where typically a single measurement per subject is available.展开更多
Background In the riverine riparian ecosystem,particularly in India,the knowledge of the effects of habitat disturbance on taxonomic distinctness,functional diversity,and local contribution toβdiversity(LCBD)of spide...Background In the riverine riparian ecosystem,particularly in India,the knowledge of the effects of habitat disturbance on taxonomic distinctness,functional diversity,and local contribution toβdiversity(LCBD)of spider community is elusive.The present study examined the relationships between the index of taxonomic distinctness(Δ^(+)),index of variation in taxonomic distinctness(λ^(+)),functional evenness(FEve),functional divergence(FDiv),functional dispersion(FDis),and LCBD of spider community of the Ganga River and the effects of habitat disturbance on these indices.A total of 27 sampling sites were selected along the bank of the Ganga River.Based on the rating of the disturbance scores,the sites were classified into lowly,moderately,and highly disturbed sites.To understand the relationships between species richness,Δ^(+),λ^(+),FDis,FDiv,FEve,LCBD,and habitat disturbance score,Pearson’s correlation was calculated,followed by the linear regression model.The one-way multivariate analysis of variance was used to find differences in taxonomic distinctness and functional diversity in the different disturbed sites.Results Significant relationships were found betweenλ^(+)andΔ^(+),FDis andΔ^(+),FDis andλ^(+),FDiv and species richness,FEve and species richness,FEve andλ^(+),FEve and habitat disturbance,LCBD and FEve,and LCBD and habitat disturbance.A significant difference was present in the indices of functional diversity between the lowly,moderately,and highly disturbed sites.Agriculture,garbage dump,human settlement,and created embankment influenced the spider community’sλ^(+),FEve,and LCBD.Conclusion Unrestrained anthropogenic activities exacerbate habitat disturbance by affecting ecological processes.Thus,understanding linkages between ecosystem disturbance,taxonomic,functional,andβdiversity can be fundamental to managing and conserving natural resources.This work highlights the importance of including taxonomic and functional diversity to comprehend the impact of habitat disturbance on riverine riparian spiders beyond just the number of species.An integrated taxonomic and functional diversity approach coupled withβdiversity can be used to support environmental assessment,restoration,and conservation planning of the biological resources of the Ganges River.展开更多
Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using a...Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.展开更多
Borehole instability in naturally fractured rocks poses significant challenges to drilling.Drilling mud invades the surrounding formations through natural fractures under the difference between the wellbore pressure(P...Borehole instability in naturally fractured rocks poses significant challenges to drilling.Drilling mud invades the surrounding formations through natural fractures under the difference between the wellbore pressure(P w)and pore pressure(P p)during drilling,which may cause wellbore instability.However,the weakening of fracture strength due to mud intrusion is not considered in most existing borehole stability analyses,which may yield significant errors and misleading predictions.In addition,only limited factors were analyzed,and the fracture distribution was oversimplified.In this paper,the impacts of mud intrusion and associated fracture strength weakening on borehole stability in fractured rocks under both isotropic and anisotropic stress states are investigated using a coupled DEM(distinct element method)and DFN(discrete fracture network)method.It provides estimates of the effect of fracture strength weakening,wellbore pressure,in situ stresses,and sealing efficiency on borehole stability.The results show that mud intrusion and weakening of fracture strength can damage the borehole.This is demonstrated by the large displacement around the borehole,shear displacement on natural fractures,and the generation of fracture at shear limit.Mud intrusion reduces the shear strength of the fracture surface and leads to shear failure,which explains that the increase in mud weight may worsen borehole stability during overbalanced drilling in fractured formations.A higher in situ stress anisotropy exerts a significant influence on the mechanism of shear failure distribution around the wellbore.Moreover,the effect of sealing natural fractures on maintaining borehole stability is verified in this study,and the increase in sealing efficiency reduces the radial invasion distance of drilling mud.This study provides a directly quantitative prediction method of borehole instability in naturally fractured formations,which can consider the discrete fracture network,mud intrusion,and associated weakening of fracture strength.The information provided by the numerical approach(e.g.displacement around the borehole,shear displacement on fracture,and fracture at shear limit)is helpful for managing wellbore stability and designing wellbore-strengthening operations.展开更多
The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of...The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium theory.The results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition characteristics.Generally,failure first occurs in certain superimposed strata slightly far from the goaf.Subsequently,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the goaf.This process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the goaf.The deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping discontinuities.The effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than expected.The strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling failure.However,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever beams.By taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the key stratum,moving downward toward and upwards away from the goaf.展开更多
This paper investigates the verb valency structure of English that is used by English as Foreign Language(EFL)learners from a corpus-driven perspective.Specifically,it focuses on the usage of the verbs“suggest”and“...This paper investigates the verb valency structure of English that is used by English as Foreign Language(EFL)learners from a corpus-driven perspective.Specifically,it focuses on the usage of the verbs“suggest”and“advise”in a selected corpus.By analyzing a sample of written and spoken texts,this study attempts to investigate the similarities and differences in the patterns of verb valency between native English speakers and Chinese EFL learners.The findings of this research can contribute to a better understanding of the challenges faced by Chinese EFL learners in acquiring accurate verb valency structures and provide insights for language teachers in designing effective pedagogical approaches.展开更多
A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes...A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.展开更多
By taking Bixi Town of Changshu City of Jiangsu Province in China for example,through the analysis of its development including villages types,industrial layout and existing problems,development strategies for basic f...By taking Bixi Town of Changshu City of Jiangsu Province in China for example,through the analysis of its development including villages types,industrial layout and existing problems,development strategies for basic facilities in villages of Bixi Town have been illustrated from the perspective of road system,water supply and drainage system,power supply engineer,communication facilities,cable television engineer and sanitation engineer.Strategies contain building famous historical and cultural villages,developing leisure agriculture and developing distinctive agricultural undertakings.It is expected to provide development strategies for small towns and villages under the background of new countryside construction.展开更多
As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indic...As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indices, but its ef fect on taxonomic distinctness(TD) indices is less well studied. Here, we examined the responses of traditional(species richness, Shannon-Wiener diversity) and TD(average taxonomic distinctness: Δ +, and variation in taxonomic distinctness: Λ +) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three dif ferent river systems in China. At regional scale, taxa richness asymptotically increased with ?xed-count size; ≥250–300 individuals to express 95% information of the raw data. In contrast, TD indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with ≥100 individuals needed to estimate 95% of the information of the actual Δ + and Λ + in the three river basins. We also found that abundance had a certain ef fect on diversity indices during the subsampling procedure, with dif ferent subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat type.展开更多
By using multi-objective analysis method, five architectural tourist sites with Lingnan characteristics were selected. Through the analysis on relevant data obtained by GIS, spatial analysis research had been conducte...By using multi-objective analysis method, five architectural tourist sites with Lingnan characteristics were selected. Through the analysis on relevant data obtained by GIS, spatial analysis research had been conducted on competitiveness of Lingnan distinctive architectural tourist cultural sites in Guangdong Province and some conclusions had been obtained.展开更多
Cassava (Manihot esculenta Crantz) is one of the most important economic crops in Thailand. However, the Thai cassava breeding gene pool was genetically narrow with only 11 distinct landraces. An attempt was made here...Cassava (Manihot esculenta Crantz) is one of the most important economic crops in Thailand. However, the Thai cassava breeding gene pool was genetically narrow with only 11 distinct landraces. An attempt was made here to characterize 266 cassava clones collected from 80 farms in eight provinces using 35 SSR markers. A total of 365 polymorphic alleles were detected in the assayed samples. The molecular analysis of variance revealed that a large SSR variance (19.8%) was present among the farm samples. The genetic relationships of the 266 farm samples revealed by the principal coordinate analysis confirmed the large SSR variation observed among the collected cassava samples. The average dissimilarity (AD) of a cassava sample against the other 265 samples was calculated and the AD values obtained ranged from 0.256 to 0.502 with a mean of 0.319. Based on these AD values, a set of 50 unique cassava samples with AD values of 0.346 or higher was assembled from the on-farm samples to widen the genetic base of the Thai cassava breeding gene pool.展开更多
The coastal areas of the Baja California peninsula are characterized mainly by rocky areas, where rock pools dominate as important coastal habitats because of the tide cycle, when the water is trapped during the low t...The coastal areas of the Baja California peninsula are characterized mainly by rocky areas, where rock pools dominate as important coastal habitats because of the tide cycle, when the water is trapped during the low tide, forming the pools. Environmental parameters like temperature, salinity and dissolved oxygen of the water trapped in the pools are key factors for the flora and fauna that inhabit these areas, particularly during the warmer months when the mean values of these parameters are usually higher than the mean values of the sea surface. The aim of the present study was to determine the variation of the taxonomic diversity of the fish communities that inhabit the rock pools in the common land known as Conquista Agraria in the Pacific coast of Baja California Sur, México, from 2015 to 2019. A total of 59 visual censuses were carried out monthly during the second low tide of the full moon. Temperature, salinity, and dissolved oxygen showed variation throughout the study period, with two distinct seasons (warm and cold), which influenced the taxonomic diversity and taxonomic distinctness of the species recorded in the area. There was a higher diversity in the warmer months (summer) and years (2015 and 2016). In addition, according to the MDS analysis, 2017 and 2018 showed high similarity of species.展开更多
This article briefs the past and development of independent colleges until now in China,dealing with the reasons why they have come into existence and developed in a remarkable way.A somewhat detailed analysis of thei...This article briefs the past and development of independent colleges until now in China,dealing with the reasons why they have come into existence and developed in a remarkable way.A somewhat detailed analysis of their distinctions from other higher education has been made and the further development strategies are also presented in it.展开更多
The paper attempts to make the distinction between China English and Chinglish from the different aspects,to understandmore about the relationship of them and reasons of their occurrences.With a synthesizing and compa...The paper attempts to make the distinction between China English and Chinglish from the different aspects,to understandmore about the relationship of them and reasons of their occurrences.With a synthesizing and comparative method,the study draws aclear cut between China English and Chinglish and explores their implications to EFL in China.展开更多
基金funded by the National Natural Science Foundation of China (Grant Nos.40730847,40906063 and 41076090)
文摘In this paper, we assessed the ecological and biodiversity status in the Bohai Sea through a quantitative survey on mac-rofaunal community at 25 stations in Laizhou Bay and adjacent waters in the autumn of 2006.We tested the robustness and effectiveness of taxonomic distinctness as an ecological indictor by analyzing its correlation with species richness and natural environmental variables and by analyzing other ecological indicators (Shannon-Wiener H' and W statistics from Abundance Biomass Comparison curve).Results so obtained indicated that the benthic environment of the study waters in general is not under major impact of anthropogenic disturbance, but some stations in Laizhou Bay and along the coast of the Shandong Peninsula and even in the central Bohai Sea might be moderately disturbed and showed signs of ecological degradation.The taxonomic distinctness measures △+ and Λ+ were independent of sampling effort and natural environment factors and were compliant to other ecological indicators.Further application of the taxonomic distinctness indicator to assess marine biodiversity and ecosystem health on a larger regional scale with historical data seems promising.
文摘Distinctness, Uniformity and Stability (DUS) testing is the technical base of Plant Variety Protection (PVP) and the scientific basis for the approval of Plant Breeder's Rights (PBR). DUS Test Guidelines are not only the technical manuals for the DUS testing authorities to conduct the testing, but also the technical standards for the competent authorities to examine the DUS of new varieties of plants. Tea plant, originated from Yunnan Province, China, is a very important woody cash species in the world. The International Union for the Protection of New Varieties of Plants (UPOV) DUS Test Guidelines for tea plant is the first Test Guidelines prepared by China for the UPOV. In this article, the subject, selection, and determination of characteristics, states of expression of characteristics and the selection of example varieties, assessment of the UPOV DUS Test Guidelines for tea plant were elucidated in detail. Finally, the proposal of PVP for tea plant in China was also proposed. The preparation of UPOV DUS Test Guidelines for tea plant will have important significance both for promoting the development of PVP and increasing the status of international PVP fields for China.
基金funded by the Innovation Platform for Basic Research in Breeding of Beijing, China (D08070500690801)the Science and Technology Innovation Ability Construction Projects,Beijing Academy of Agricultural and Forestry Sciences, China (KJCX20140202)
文摘Assessment of variety distinctness is important for both the registration and the protection of particular variety. However, the current testing system, which assesses a range of morphological characters of each pair of varieties grown side-by-side, is time-consuming and is not suitable for the assessment of hundreds of samples. The objective of this study was to develop a procedure for the assessment of wheat variety distinctness using simple sequence repeat(SSR) markers. A comparison between the molecular and morphological profile of 797 varieties was made. On the basis of the comparison, pairs of varieties with a genetic similarity value(GSV) ≤90% were deemed to be distinct, accounting for ~85% of varieties assessed in wheat regional trials. For the remaining ~15% of varieties, GSVs between different varieties were 〉90%, among which ~35% were not distinct and the other ~65% were distinct. Therefore, if given a GSV〉90%, the pairs of varieties should be morphologically assessed in the field. To avoid any errors in the assessments, we proposed the elimination of contaminant plants from the sample before comparing the varietal genotypes, scoring of the genotype at each locus with a pair of allele numbers when constructing a molecular profile, and faithfully recording two alleles at a non-homozygous locus. To reduce the workload and cost, a three-grade markers comparison among varieties is suggested. In addition, 80 SSR markers and a technical procedure for assessment of wheat variety distinctness have been proposed. Based on the procedure, the distinctness assessment of ~85% of all wheat varieties is completed in our laboratory annually. Consequently, total field assessment has been reduced considerably.
文摘The objectives of this study were to construct a database of expressed sequence tag (EST)-simple sequence repeat (SSR) markers to identify lettuce cultivars. A set of 370 EST-SSR primer pairs were applied for fingerprinting the lettuce cultivars. Fifty-eight EST-SSR markers showed hy-per-variability and were able to differentiate 92 cultivars. A total of 176 polymorphic amplified fragments were obtained by the 58 markers, and two to eight SSR alleles were detected for each l°Cus with an average of three alleles per locus. Average polymorphism information content (PIC) was 0.425, ranging from 0.022 to 0.743. Cluster analysis was based on Jaccard’s distance coefficients using the method of unweighted pair group. In this method we used arithmetical averages (UPGMA) algorithm categorized 4 major groups, which were in accordance to morphological traits. The eight cultivars of three groups with 100% genetic similarity through SSR analysis were investigated by phenotypic traits. These cultivars including these pairs are very similar in 27 morphological characteristics. Therefore, these EST-SSR markers could be used to select similar cultivars through management of reference collection to complement distinctiveness test of lettuce cultivars.
文摘The intertidal zone is a complex coastal area exposed to a wide variety of environmental factors. During low tide, rocky pools are exposed to air for several hours throughout the day, and environmental conditions such as temperature and salinity are highly variable. Fish communities that inhabit these tide pools are also exposed to environmental variability;therefore it is important to look at fish community structure in relation to important environmental factors such as temperature, salinity and dissolved oxygen on tide pools during spring tides, time of greater exposure to air. Therefore, the aim of the present study was to analyze the variation of the taxonomic distinctness of intertidal fish communities considering temperature, salinity and dissolved oxygen of the water that remains trapped in the tide pools during low tide. Visual census surveys were carried out monthly, from January to December 2015, in the intertidal zone of El Faro during spring tides on full moon days, when fluctuations of environmental variables are significant. Total extension of the census surveys was 156 × 5 m (780 m2). A total of 145 tide pools were sampled and divided in three groups (small, medium and large) according to size and depths that ranged from 20 to 45 cm. Temperature, salinity and dissolved oxygen fluctuate throughout the year of study. Thermal difference between open ocean and tide pools ranged from 3.5°C to 4.5°C. A total of 3757 organisms from 22 species, 12 families, four orders and one class were recorded. When comparing taxonomic distinctness and average taxonomic distinctness between months and tide pools of different sizes, values fell within the confidence intervals in the tunnel and were located close to the mean.
基金funds from the Centre National de la Recherche Scientifique,the Agence Nationale pour la Recherche(Grant No.ANR-07-PHYSIO-013-01)the Fondation pour la Recherche sur l'Hypertension Arterielle (Grant No.AO 2007)the Agence Nationale de Recherches sur le SIDA et les hepatites virales (ANRS) and the Genopole Evry (all awarded to AB),JFBG was recipient of a CONACYTMexico PhD Fellowship (Grant No.207676/302245)
文摘The problem of identifying differential activity such as in gene expression is a major defeat in biostatistics and bioinformatics. Equally important, however much less frequently studied, is the question of similar activity from one biological condition to another. The fold- change, or ratio, is usually considered a relevant criterion for stating difference and similarity between measurements. Importantly, no statistical method for concomitant evaluation of similarity and distinctness currently exists for biological applications. Modern micro- array, digital PCR (dPCR), and Next-Generation Sequencing (NGS) technologies frequently provide a means of coeff^cient of variation estimation for individual measurements. Using fold-change, and by making the assumption that measurements are normally distributed with known variances, we designed a novel statistical test that allows us to detect concomitantly, thus using the same formalism, differ- entially and similarly expressed genes (http:]]cds.ihes.fr). Given two sets of gene measurements in different biological conditions, the probabilities of making type I and type II errors in stating that a gene is differentially or similarly expressed from one condition to the other can be calculated. Furthermore, a confidence interval for the fold-change can be delineated. Finally, we demonstrate that the assumption of normality can be relaxed to consider arbitrary distributions numerically. The Concomitant evaluation of Distinctness and Similarity (CDS) statistical test correctly estimates similarities and differences between measurements of gene expression. The imple- mentation, being time and memory efficient, allows the use of the CDS test in high-throughput data analysis such as microarray, dPCR, and NGS experiments. Importantly, the CDS test can be applied to the comparison of single measurements (N = 1) provided the var- iance (or coefficient of variation) of the signals is known, making CDS a valuable tool also in biomedical analysis where typically a single measurement per subject is available.
基金National Mission for Clean Ganga(NMCG),Ministry of Jal Shakti,Government of India(Grant No.B-02/2015-16/1259/NMCG-WII PROPOSAL and B-03/2015-16/1077/NMCG-NEW PROPASAL).
文摘Background In the riverine riparian ecosystem,particularly in India,the knowledge of the effects of habitat disturbance on taxonomic distinctness,functional diversity,and local contribution toβdiversity(LCBD)of spider community is elusive.The present study examined the relationships between the index of taxonomic distinctness(Δ^(+)),index of variation in taxonomic distinctness(λ^(+)),functional evenness(FEve),functional divergence(FDiv),functional dispersion(FDis),and LCBD of spider community of the Ganga River and the effects of habitat disturbance on these indices.A total of 27 sampling sites were selected along the bank of the Ganga River.Based on the rating of the disturbance scores,the sites were classified into lowly,moderately,and highly disturbed sites.To understand the relationships between species richness,Δ^(+),λ^(+),FDis,FDiv,FEve,LCBD,and habitat disturbance score,Pearson’s correlation was calculated,followed by the linear regression model.The one-way multivariate analysis of variance was used to find differences in taxonomic distinctness and functional diversity in the different disturbed sites.Results Significant relationships were found betweenλ^(+)andΔ^(+),FDis andΔ^(+),FDis andλ^(+),FDiv and species richness,FEve and species richness,FEve andλ^(+),FEve and habitat disturbance,LCBD and FEve,and LCBD and habitat disturbance.A significant difference was present in the indices of functional diversity between the lowly,moderately,and highly disturbed sites.Agriculture,garbage dump,human settlement,and created embankment influenced the spider community’sλ^(+),FEve,and LCBD.Conclusion Unrestrained anthropogenic activities exacerbate habitat disturbance by affecting ecological processes.Thus,understanding linkages between ecosystem disturbance,taxonomic,functional,andβdiversity can be fundamental to managing and conserving natural resources.This work highlights the importance of including taxonomic and functional diversity to comprehend the impact of habitat disturbance on riverine riparian spiders beyond just the number of species.An integrated taxonomic and functional diversity approach coupled withβdiversity can be used to support environmental assessment,restoration,and conservation planning of the biological resources of the Ganges River.
基金This work is supported by Demonstration of Scientific and Technology Achievements Transform in Sichuan Province under Grant 2022ZHCG0036National Natural Science Foundation of China(62002047).
文摘Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52074312 and 52211530097)CNPC Science and Technology Innovation Foundation(Grant No.2021DQ02-0505).
文摘Borehole instability in naturally fractured rocks poses significant challenges to drilling.Drilling mud invades the surrounding formations through natural fractures under the difference between the wellbore pressure(P w)and pore pressure(P p)during drilling,which may cause wellbore instability.However,the weakening of fracture strength due to mud intrusion is not considered in most existing borehole stability analyses,which may yield significant errors and misleading predictions.In addition,only limited factors were analyzed,and the fracture distribution was oversimplified.In this paper,the impacts of mud intrusion and associated fracture strength weakening on borehole stability in fractured rocks under both isotropic and anisotropic stress states are investigated using a coupled DEM(distinct element method)and DFN(discrete fracture network)method.It provides estimates of the effect of fracture strength weakening,wellbore pressure,in situ stresses,and sealing efficiency on borehole stability.The results show that mud intrusion and weakening of fracture strength can damage the borehole.This is demonstrated by the large displacement around the borehole,shear displacement on natural fractures,and the generation of fracture at shear limit.Mud intrusion reduces the shear strength of the fracture surface and leads to shear failure,which explains that the increase in mud weight may worsen borehole stability during overbalanced drilling in fractured formations.A higher in situ stress anisotropy exerts a significant influence on the mechanism of shear failure distribution around the wellbore.Moreover,the effect of sealing natural fractures on maintaining borehole stability is verified in this study,and the increase in sealing efficiency reduces the radial invasion distance of drilling mud.This study provides a directly quantitative prediction method of borehole instability in naturally fractured formations,which can consider the discrete fracture network,mud intrusion,and associated weakening of fracture strength.The information provided by the numerical approach(e.g.displacement around the borehole,shear displacement on fracture,and fracture at shear limit)is helpful for managing wellbore stability and designing wellbore-strengthening operations.
基金Financial support for this work was provided by the Youth Fund Program of the National Natural Science Foundation of China (No. 42002292)the General Program of the National Natural Science Foundation of China (No. 42377175)the General Program of the Hubei Provincial Natural Science Foundation, China (No. 2023AFB631)
文摘The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical simulations.Moreover,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium theory.The results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition characteristics.Generally,failure first occurs in certain superimposed strata slightly far from the goaf.Subsequently,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the goaf.This process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the goaf.The deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping discontinuities.The effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than expected.The strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling failure.However,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever beams.By taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the key stratum,moving downward toward and upwards away from the goaf.
文摘This paper investigates the verb valency structure of English that is used by English as Foreign Language(EFL)learners from a corpus-driven perspective.Specifically,it focuses on the usage of the verbs“suggest”and“advise”in a selected corpus.By analyzing a sample of written and spoken texts,this study attempts to investigate the similarities and differences in the patterns of verb valency between native English speakers and Chinese EFL learners.The findings of this research can contribute to a better understanding of the challenges faced by Chinese EFL learners in acquiring accurate verb valency structures and provide insights for language teachers in designing effective pedagogical approaches.
文摘A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.
文摘By taking Bixi Town of Changshu City of Jiangsu Province in China for example,through the analysis of its development including villages types,industrial layout and existing problems,development strategies for basic facilities in villages of Bixi Town have been illustrated from the perspective of road system,water supply and drainage system,power supply engineer,communication facilities,cable television engineer and sanitation engineer.Strategies contain building famous historical and cultural villages,developing leisure agriculture and developing distinctive agricultural undertakings.It is expected to provide development strategies for small towns and villages under the background of new countryside construction.
基金Supported by the National Natural Science Foundation of China(Nos.31400469,41571495,31770460)the National Science and Technology Basic Research Program(No.2015FY110400-4)+2 种基金the China Three Gorges Corporation Research Project(No.JGJ/0272015)the Key Program of the Chinese Academy of Sciences(Comprehensive Assessment Technology of River Ecology and Environment for the Water Source Region of "South-toNorth Water Diversion Central Route")the Program for Biodiversity Protection(No.2017HB2096001006)
文摘As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indices, but its ef fect on taxonomic distinctness(TD) indices is less well studied. Here, we examined the responses of traditional(species richness, Shannon-Wiener diversity) and TD(average taxonomic distinctness: Δ +, and variation in taxonomic distinctness: Λ +) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three dif ferent river systems in China. At regional scale, taxa richness asymptotically increased with ?xed-count size; ≥250–300 individuals to express 95% information of the raw data. In contrast, TD indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with ≥100 individuals needed to estimate 95% of the information of the actual Δ + and Λ + in the three river basins. We also found that abundance had a certain ef fect on diversity indices during the subsampling procedure, with dif ferent subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat type.
基金Supported by Basic Tourism which is the Elaborate Course of Guang-zhou Vocational College of Technology and BusinessSubtopic of 863Key Program (2006AA06A306 )+1 种基金Key Item of Weather Bureau of Shandong Province (2009sdqxz16)Geochemical Investigation Data-base (INFO-115-C01-SDB4-06) ~~
文摘By using multi-objective analysis method, five architectural tourist sites with Lingnan characteristics were selected. Through the analysis on relevant data obtained by GIS, spatial analysis research had been conducted on competitiveness of Lingnan distinctive architectural tourist cultural sites in Guangdong Province and some conclusions had been obtained.
文摘Cassava (Manihot esculenta Crantz) is one of the most important economic crops in Thailand. However, the Thai cassava breeding gene pool was genetically narrow with only 11 distinct landraces. An attempt was made here to characterize 266 cassava clones collected from 80 farms in eight provinces using 35 SSR markers. A total of 365 polymorphic alleles were detected in the assayed samples. The molecular analysis of variance revealed that a large SSR variance (19.8%) was present among the farm samples. The genetic relationships of the 266 farm samples revealed by the principal coordinate analysis confirmed the large SSR variation observed among the collected cassava samples. The average dissimilarity (AD) of a cassava sample against the other 265 samples was calculated and the AD values obtained ranged from 0.256 to 0.502 with a mean of 0.319. Based on these AD values, a set of 50 unique cassava samples with AD values of 0.346 or higher was assembled from the on-farm samples to widen the genetic base of the Thai cassava breeding gene pool.
文摘The coastal areas of the Baja California peninsula are characterized mainly by rocky areas, where rock pools dominate as important coastal habitats because of the tide cycle, when the water is trapped during the low tide, forming the pools. Environmental parameters like temperature, salinity and dissolved oxygen of the water trapped in the pools are key factors for the flora and fauna that inhabit these areas, particularly during the warmer months when the mean values of these parameters are usually higher than the mean values of the sea surface. The aim of the present study was to determine the variation of the taxonomic diversity of the fish communities that inhabit the rock pools in the common land known as Conquista Agraria in the Pacific coast of Baja California Sur, México, from 2015 to 2019. A total of 59 visual censuses were carried out monthly during the second low tide of the full moon. Temperature, salinity, and dissolved oxygen showed variation throughout the study period, with two distinct seasons (warm and cold), which influenced the taxonomic diversity and taxonomic distinctness of the species recorded in the area. There was a higher diversity in the warmer months (summer) and years (2015 and 2016). In addition, according to the MDS analysis, 2017 and 2018 showed high similarity of species.
文摘This article briefs the past and development of independent colleges until now in China,dealing with the reasons why they have come into existence and developed in a remarkable way.A somewhat detailed analysis of their distinctions from other higher education has been made and the further development strategies are also presented in it.
文摘The paper attempts to make the distinction between China English and Chinglish from the different aspects,to understandmore about the relationship of them and reasons of their occurrences.With a synthesizing and comparative method,the study draws aclear cut between China English and Chinglish and explores their implications to EFL in China.