Blasting is well-known as an effective method for fragmenting or moving rock in open-pit mines.To evaluate the quality of blasting,the size of rock distribution is used as a critical criterion in blasting operations.A...Blasting is well-known as an effective method for fragmenting or moving rock in open-pit mines.To evaluate the quality of blasting,the size of rock distribution is used as a critical criterion in blasting operations.A high percentage of oversized rocks generated by blasting operations can lead to economic and environmental damage.Therefore,this study proposed four novel intelligent models to predict the size of rock distribution in mine blasting in order to optimize blasting parameters,as well as the efficiency of blasting operation in open mines.Accordingly,a nature-inspired algorithm(i.e.,firefly algorithm-FFA)and different machine learning algorithms(i.e.,gradient boosting machine(GBM),support vector machine(SVM),Gaussian process(GP),and artificial neural network(ANN))were combined for this aim,abbreviated as FFA-GBM,FFA-SVM,FFA-GP,and FFA-ANN,respectively.Subsequently,predicted results from the abovementioned models were compared with each other using three statistical indicators(e.g.,mean absolute error,root-mean-squared error,and correlation coefficient)and color intensity method.For developing and simulating the size of rock in blasting operations,136 blasting events with their images were collected and analyzed by the Split-Desktop software.In which,111 events were randomly selected for the development and optimization of the models.Subsequently,the remaining 25 blasting events were applied to confirm the accuracy of the proposed models.Herein,blast design parameters were regarded as input variables to predict the size of rock in blasting operations.Finally,the obtained results revealed that the FFA is a robust optimization algorithm for estimating rock fragmentation in bench blasting.Among the models developed in this study,FFA-GBM provided the highest accuracy in predicting the size of fragmented rocks.The other techniques(i.e.,FFA-SVM,FFA-GP,and FFA-ANN)yielded lower computational stability and efficiency.Hence,the FFA-GBM model can be used as a powerful and precise soft computing tool that can be appl展开更多
目的评估密度梯度离心联合上游法改善精子DNA碎片(sperm DNA fragmentation)的效率及其对体外受精-胚胎移植(IVF-ET)妊娠结局的影响。方法收集120份处理前后的精液,用精子染色质扩散法检测精子DNA碎片,评估其对100个新鲜移植患者妊娠结...目的评估密度梯度离心联合上游法改善精子DNA碎片(sperm DNA fragmentation)的效率及其对体外受精-胚胎移植(IVF-ET)妊娠结局的影响。方法收集120份处理前后的精液,用精子染色质扩散法检测精子DNA碎片,评估其对100个新鲜移植患者妊娠结局的影响。结果优选后,男性不育组精子DNA碎片率(SDFI)由22.75(14.44,30.25)降至11.5(5.60,22.79),对照组则由20.86(15.00,26.81)降至7.5(3.63,15.44);妊娠组精子DNA碎片明显低于非妊娠组,ROC曲线下面积是0.667;高水平组(DFI≥20%)的妊娠率和出生率低于低水平组(DFI<20%),差异有统计学意义。结论密度梯度离心联合上游法可减少精子DNA碎片;优选后DNA碎片对IVF-ET妊娠结局具有预测价值,一旦超过阈值,虽可正常受精,但妊娠率和出生率下降。展开更多
A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are densitygradient centrifugation （DGC） and swim-up （SUP）. To date, these methods appear to b...A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are densitygradient centrifugation （DGC） and swim-up （SUP）. To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques （ART）, but they may have negative effects on sperm DNA. In this study, the ability of these semen processing techniques to eliminate spermatozoa containing single- and double-strand DNA damage was assessed by the two-tailed comet assay and the sperm chromatin dispersion test in 157 semen samples from patients seeking assisted reproduction treatment. Our results indicated that SUP and DGC are equally efficient in eliminating spermatozoa containing double-strand DNA damage and sperm with highly damaged （degraded） DNA, as characterized by the presence of both single- and double-strand DNA breaks. However, DGC is more efficient than SUP in selecting spermatozoa that are free from single-strand DNA damage. Future studies should characterise the importance of the various types of DNA damage and examine the sperm processing protocols used in each laboratory to determine their ability to eliminate DNA damage and hence, prevent the potential transmission of genetic mutations via ART.展开更多
Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitat...Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitats of Kuwait on diversity,composition,identity and assemblage of vascular plant species.Plant survey data from 113 plots （5m×5m each） were randomly selected in 51 sites at coastal fragmented habitats at three levels of disturbance intensities （high,moderate and low） and were statistically analyzed.The results revealed that about 76% of the recorded species are considered threatened species in Kuwait,most of which are being lost in high disturbed habitats.Disturbance led to the dominance of Zygophyllum qatarense,Cornulaca aucheri and Salsola imbricata,which are species of disturbance indicators.Richness,total plant cover and species diversity were higher in moderate and low disturbed habitats than in high disturbed habitats.Beta diversity between high and low disturbed habitats was higher than either between high and moderate,or between moderate and low disturbed habitats.Cluster analyses showed statistically significant differences in composition of plant assemblages,which indicate high beta diversity between the habitat types.Intensive urbanization and industrialization are among the most serious threats that contribute to declines in biological diversity and rapid fragmentation of coastal habitats in Kuwait.Establishing protective enclosures in the disturbed habitats,planting endangered and vulnerable species,and establishing a natural reserve at Nuwaiseeb are recommended conservation actions to avoid loss of the fragmented coastal habitats and to facilitate restoration of native plants.展开更多
基金supported by the Center for Mining,Electro-Mechanical research of Hanoi University of Mining and Geology(HUMG),Hanoi,Vietnamfinancially supported by the Hunan Provincial Department of Education General Project(19C1744)+1 种基金Hunan Province Science Foundation for Youth Scholars of China fund(2018JJ3510)the Innovation-Driven Project of Central South University(2020CX040)。
文摘Blasting is well-known as an effective method for fragmenting or moving rock in open-pit mines.To evaluate the quality of blasting,the size of rock distribution is used as a critical criterion in blasting operations.A high percentage of oversized rocks generated by blasting operations can lead to economic and environmental damage.Therefore,this study proposed four novel intelligent models to predict the size of rock distribution in mine blasting in order to optimize blasting parameters,as well as the efficiency of blasting operation in open mines.Accordingly,a nature-inspired algorithm(i.e.,firefly algorithm-FFA)and different machine learning algorithms(i.e.,gradient boosting machine(GBM),support vector machine(SVM),Gaussian process(GP),and artificial neural network(ANN))were combined for this aim,abbreviated as FFA-GBM,FFA-SVM,FFA-GP,and FFA-ANN,respectively.Subsequently,predicted results from the abovementioned models were compared with each other using three statistical indicators(e.g.,mean absolute error,root-mean-squared error,and correlation coefficient)and color intensity method.For developing and simulating the size of rock in blasting operations,136 blasting events with their images were collected and analyzed by the Split-Desktop software.In which,111 events were randomly selected for the development and optimization of the models.Subsequently,the remaining 25 blasting events were applied to confirm the accuracy of the proposed models.Herein,blast design parameters were regarded as input variables to predict the size of rock in blasting operations.Finally,the obtained results revealed that the FFA is a robust optimization algorithm for estimating rock fragmentation in bench blasting.Among the models developed in this study,FFA-GBM provided the highest accuracy in predicting the size of fragmented rocks.The other techniques(i.e.,FFA-SVM,FFA-GP,and FFA-ANN)yielded lower computational stability and efficiency.Hence,the FFA-GBM model can be used as a powerful and precise soft computing tool that can be appl
文摘目的评估密度梯度离心联合上游法改善精子DNA碎片(sperm DNA fragmentation)的效率及其对体外受精-胚胎移植(IVF-ET)妊娠结局的影响。方法收集120份处理前后的精液,用精子染色质扩散法检测精子DNA碎片,评估其对100个新鲜移植患者妊娠结局的影响。结果优选后,男性不育组精子DNA碎片率(SDFI)由22.75(14.44,30.25)降至11.5(5.60,22.79),对照组则由20.86(15.00,26.81)降至7.5(3.63,15.44);妊娠组精子DNA碎片明显低于非妊娠组,ROC曲线下面积是0.667;高水平组(DFI≥20%)的妊娠率和出生率低于低水平组(DFI<20%),差异有统计学意义。结论密度梯度离心联合上游法可减少精子DNA碎片;优选后DNA碎片对IVF-ET妊娠结局具有预测价值,一旦超过阈值,虽可正常受精,但妊娠率和出生率下降。
文摘A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are densitygradient centrifugation （DGC） and swim-up （SUP）. To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques （ART）, but they may have negative effects on sperm DNA. In this study, the ability of these semen processing techniques to eliminate spermatozoa containing single- and double-strand DNA damage was assessed by the two-tailed comet assay and the sperm chromatin dispersion test in 157 semen samples from patients seeking assisted reproduction treatment. Our results indicated that SUP and DGC are equally efficient in eliminating spermatozoa containing double-strand DNA damage and sperm with highly damaged （degraded） DNA, as characterized by the presence of both single- and double-strand DNA breaks. However, DGC is more efficient than SUP in selecting spermatozoa that are free from single-strand DNA damage. Future studies should characterise the importance of the various types of DNA damage and examine the sperm processing protocols used in each laboratory to determine their ability to eliminate DNA damage and hence, prevent the potential transmission of genetic mutations via ART.
文摘Knowledge about plant diversity along disturbance gradients is essential for conservation and management of fragmented coastal habitats.This study examined the effects of human disturbance intensity in coastal habitats of Kuwait on diversity,composition,identity and assemblage of vascular plant species.Plant survey data from 113 plots （5m×5m each） were randomly selected in 51 sites at coastal fragmented habitats at three levels of disturbance intensities （high,moderate and low） and were statistically analyzed.The results revealed that about 76% of the recorded species are considered threatened species in Kuwait,most of which are being lost in high disturbed habitats.Disturbance led to the dominance of Zygophyllum qatarense,Cornulaca aucheri and Salsola imbricata,which are species of disturbance indicators.Richness,total plant cover and species diversity were higher in moderate and low disturbed habitats than in high disturbed habitats.Beta diversity between high and low disturbed habitats was higher than either between high and moderate,or between moderate and low disturbed habitats.Cluster analyses showed statistically significant differences in composition of plant assemblages,which indicate high beta diversity between the habitat types.Intensive urbanization and industrialization are among the most serious threats that contribute to declines in biological diversity and rapid fragmentation of coastal habitats in Kuwait.Establishing protective enclosures in the disturbed habitats,planting endangered and vulnerable species,and establishing a natural reserve at Nuwaiseeb are recommended conservation actions to avoid loss of the fragmented coastal habitats and to facilitate restoration of native plants.
