The Upper Cretaceous of Tantou Basin in western Henan has yielded many vertebrate fossils,which are featured by several non-avian dinosaurs.Meanwhile,studies on their eggs were yet inadequate though many eggshells hav...The Upper Cretaceous of Tantou Basin in western Henan has yielded many vertebrate fossils,which are featured by several non-avian dinosaurs.Meanwhile,studies on their eggs were yet inadequate though many eggshells have been reported.The newly discovered material 41HⅤ0199 was excavated from the Upper Cretaceous Qiupa Formation in 2021.The block preserves eight complete eggs arranged in two partial rings that form a partial clutch,and there are some scattered eggshells preserved closely with the block,showing a concave-up to concave-down ratio of 54.5:45.5,which indicates that the scattered eggshells come from the clutch and the clutch had been partially broken before it was buried.Based on morphological and microstructural characteristics,the eggs and eggshells can be assigned to Macroolithus yaotunensis(Elongatoolithidae),an oospecies known to be related to oviraptorids,which leads Yulong mini to be its probable producer.Besides,some eggshells show microstructural signs indicating egg retention,which marks the second example of egg retention in the oofamily Elongatoolithidae.展开更多
科学的轨道交通出行模式分析是运营决策优化的重要依据。为挖掘城市轨道交通时空流动特征及其影响机理,提出一种基于非负张量分解的OD客流强度时空分布计算方法,采用融合SHAP归因分析的极端梯度提升树(eXtreme Gradient Boosting,XGBoo...科学的轨道交通出行模式分析是运营决策优化的重要依据。为挖掘城市轨道交通时空流动特征及其影响机理,提出一种基于非负张量分解的OD客流强度时空分布计算方法,采用融合SHAP归因分析的极端梯度提升树(eXtreme Gradient Boosting,XGBoost)对各模式OD客流强度进行拟合预测。使用城市轨道交通AFC(automatic fare collection system,AFC)系统数据,从空间、时段以及出行日3个维度构建3阶客流OD张量,采用交替非负最小二乘法(alternating non negative least squares,ANLS)实现非负CP张量分解。基于张量分解结果,从北京轨道交通344个站点连续1周16266966条出行数据中,提取出晨高峰长距离通勤、早高峰中短通勤、平峰休闲中转出行、晚归出行4种出行模式的时、空分布特征。基于可解释性机器学习模型,对各模式OD客流进行预测。结果表明XGBoost与CatBoost、LightGBM、OLS相比更具优势。根据OD起终点站域环境特征,考虑起终点缓冲区内各类兴趣点(point of interest,POI)数量、小区住户数、房价、人口数量、站点偏离距离以及出行距离等指标,构建OD强度关联指标体系,解释各指标对OD客流强度的正负反馈效应。SHAP归因分析说明,居民更倾向于14站以内的中短途出行,并分别得到了就业类POI数目对晨、早通勤客流正向影响,以及餐饮类POI数目对休闲中转出行客流正向影响的临界阈值。该方法可为轨道交通精细化出行引导和客流组织提供数据支撑,优化城市轨道交通供需平衡及服务水平。展开更多
2,4-dienoyl CoA reductase gene （DECR 1） is mapped on pig 4 q1.2, includes ten exons and nine introns of variable size that span 30 kb. DECR 1 gene participates in the β-oxidation pathway, affects the content of int...2,4-dienoyl CoA reductase gene （DECR 1） is mapped on pig 4 q1.2, includes ten exons and nine introns of variable size that span 30 kb. DECR 1 gene participates in the β-oxidation pathway, affects the content of intramuscular fatty acid, especially the percentage of linoleic acid. The expression of DECR 1 gene has important influence on IMF, the pH, and the meat colour of pork further affects the meat quality.展开更多
Genetic characters of 10 soybean breeds in Heilongjiang Province were studied using RAPD technique. We calculated the genetic similarity and genetic distance, made the cluster analysis, and also studied the genetic re...Genetic characters of 10 soybean breeds in Heilongjiang Province were studied using RAPD technique. We calculated the genetic similarity and genetic distance, made the cluster analysis, and also studied the genetic relationship among the 10 breeds. We found 93 amplification segments by RAPE） analysis, in which there were 70 polymorphism segments, 75.26% of amplification segments, using 13 random primers, 11, 12, 5, 4, 7, 8, 3, 7, 2, 5, 10, 10, 9 amplificated bands were found. There were 7.15 bands per primer in average, The genetic similarity among the breeds ranged from 0.6848 to 0.9019, and the genetic distance ranged from 0.0981 to 0.3152. Genetic relationship between 90035 and 9674 was the closest, and between Heifeng 27 and 90035 was the farthest. Protein analysis revealed that the closest genetic relationship was between 90035 and 90024, and the farthest was between 1330 and Sui 4, and between 1330 and Heinong 39.展开更多
Polymorphisms of porcine ob exon 1 and exon 2 among different breeds including Landrace, Duroc, Min pig, Yorkshire pig, double-muscled Yorkshire, Sanjiang pig, wild boar and cross bred pig were analyzed by PCR-SSCP in...Polymorphisms of porcine ob exon 1 and exon 2 among different breeds including Landrace, Duroc, Min pig, Yorkshire pig, double-muscled Yorkshire, Sanjiang pig, wild boar and cross bred pig were analyzed by PCR-SSCP in the current study. Three pairs of primers according to the ob cDNA sequence obtained from GenBank database were designed to amplify the first two exons, which were then genotyped by SSCP. The T to C transversion was found in exon 2, which resulted in 3 genotypes named AA, AB and BB, respectively in these different porcine breeds. There was only genotype of BB in the Min pig, while no allele B was detected in double-muscled Yorkshire, and the 3 genotypes all existed in other breeds. There was significant difference on the genotype frequencies in various breeds. There was a trend that the frequency of allele A was positively associated with muscle ratio distribution on the one hand, and on the other hand, it was linked to the selected direction. So the allele A could be used as a selective marker of high muscle ratio in pig breeding.展开更多
文摘The Upper Cretaceous of Tantou Basin in western Henan has yielded many vertebrate fossils,which are featured by several non-avian dinosaurs.Meanwhile,studies on their eggs were yet inadequate though many eggshells have been reported.The newly discovered material 41HⅤ0199 was excavated from the Upper Cretaceous Qiupa Formation in 2021.The block preserves eight complete eggs arranged in two partial rings that form a partial clutch,and there are some scattered eggshells preserved closely with the block,showing a concave-up to concave-down ratio of 54.5:45.5,which indicates that the scattered eggshells come from the clutch and the clutch had been partially broken before it was buried.Based on morphological and microstructural characteristics,the eggs and eggshells can be assigned to Macroolithus yaotunensis(Elongatoolithidae),an oospecies known to be related to oviraptorids,which leads Yulong mini to be its probable producer.Besides,some eggshells show microstructural signs indicating egg retention,which marks the second example of egg retention in the oofamily Elongatoolithidae.
文摘科学的轨道交通出行模式分析是运营决策优化的重要依据。为挖掘城市轨道交通时空流动特征及其影响机理,提出一种基于非负张量分解的OD客流强度时空分布计算方法,采用融合SHAP归因分析的极端梯度提升树(eXtreme Gradient Boosting,XGBoost)对各模式OD客流强度进行拟合预测。使用城市轨道交通AFC(automatic fare collection system,AFC)系统数据,从空间、时段以及出行日3个维度构建3阶客流OD张量,采用交替非负最小二乘法(alternating non negative least squares,ANLS)实现非负CP张量分解。基于张量分解结果,从北京轨道交通344个站点连续1周16266966条出行数据中,提取出晨高峰长距离通勤、早高峰中短通勤、平峰休闲中转出行、晚归出行4种出行模式的时、空分布特征。基于可解释性机器学习模型,对各模式OD客流进行预测。结果表明XGBoost与CatBoost、LightGBM、OLS相比更具优势。根据OD起终点站域环境特征,考虑起终点缓冲区内各类兴趣点(point of interest,POI)数量、小区住户数、房价、人口数量、站点偏离距离以及出行距离等指标,构建OD强度关联指标体系,解释各指标对OD客流强度的正负反馈效应。SHAP归因分析说明,居民更倾向于14站以内的中短途出行,并分别得到了就业类POI数目对晨、早通勤客流正向影响,以及餐饮类POI数目对休闲中转出行客流正向影响的临界阈值。该方法可为轨道交通精细化出行引导和客流组织提供数据支撑,优化城市轨道交通供需平衡及服务水平。
基金Supported by Heilongjiang Province Tackle Key Problem Item(GB01B104)
文摘2,4-dienoyl CoA reductase gene （DECR 1） is mapped on pig 4 q1.2, includes ten exons and nine introns of variable size that span 30 kb. DECR 1 gene participates in the β-oxidation pathway, affects the content of intramuscular fatty acid, especially the percentage of linoleic acid. The expression of DECR 1 gene has important influence on IMF, the pH, and the meat colour of pork further affects the meat quality.
文摘Genetic characters of 10 soybean breeds in Heilongjiang Province were studied using RAPD technique. We calculated the genetic similarity and genetic distance, made the cluster analysis, and also studied the genetic relationship among the 10 breeds. We found 93 amplification segments by RAPE） analysis, in which there were 70 polymorphism segments, 75.26% of amplification segments, using 13 random primers, 11, 12, 5, 4, 7, 8, 3, 7, 2, 5, 10, 10, 9 amplificated bands were found. There were 7.15 bands per primer in average, The genetic similarity among the breeds ranged from 0.6848 to 0.9019, and the genetic distance ranged from 0.0981 to 0.3152. Genetic relationship between 90035 and 9674 was the closest, and between Heifeng 27 and 90035 was the farthest. Protein analysis revealed that the closest genetic relationship was between 90035 and 90024, and the farthest was between 1330 and Sui 4, and between 1330 and Heinong 39.
文摘Polymorphisms of porcine ob exon 1 and exon 2 among different breeds including Landrace, Duroc, Min pig, Yorkshire pig, double-muscled Yorkshire, Sanjiang pig, wild boar and cross bred pig were analyzed by PCR-SSCP in the current study. Three pairs of primers according to the ob cDNA sequence obtained from GenBank database were designed to amplify the first two exons, which were then genotyped by SSCP. The T to C transversion was found in exon 2, which resulted in 3 genotypes named AA, AB and BB, respectively in these different porcine breeds. There was only genotype of BB in the Min pig, while no allele B was detected in double-muscled Yorkshire, and the 3 genotypes all existed in other breeds. There was significant difference on the genotype frequencies in various breeds. There was a trend that the frequency of allele A was positively associated with muscle ratio distribution on the one hand, and on the other hand, it was linked to the selected direction. So the allele A could be used as a selective marker of high muscle ratio in pig breeding.
