针对分类问题,本文提出了稀疏组Lasso支持向量机方法(Sparse group lasso SVM,SGLSVM),即在SVM模型的损失函数中引入SGL惩罚函数,能同时进行组间变量和组内变量的筛选。由于SGL-SVM的目标函数求解比较复杂,本文又提出了一种快速的双层...针对分类问题,本文提出了稀疏组Lasso支持向量机方法(Sparse group lasso SVM,SGLSVM),即在SVM模型的损失函数中引入SGL惩罚函数,能同时进行组间变量和组内变量的筛选。由于SGL-SVM的目标函数求解比较复杂,本文又提出了一种快速的双层坐标下降算法。通过模拟实验,发现SGL-SVM方法在预测效果和变量选择上均要优于其他方法,对于变量具有自然分组结构且组内是稀疏的数据,本文方法在提高变量选择效果的同时又能提高模型的预测精度。最后,本文将SGL-SVM方法应用到我国制造业上市公司财务困境预测中。展开更多
Grain yield is a polygenic trait that can be influenced by environmental factors and genetic compositions at all plant growth stages.Currently,the molecular mechanisms behind the coordination of the interaction betwee...Grain yield is a polygenic trait that can be influenced by environmental factors and genetic compositions at all plant growth stages.Currently,the molecular mechanisms behind the coordination of the interaction between grain yield-related traits remain unknown.In this study,we characterized the function of four STRESS_tolerance and GRAIN_LENGTH(Os SGL)Poaceae ortholog genes that are transcribed into DUF1645 domain-containing proteins in relation to the grain length,grain weight,and drought stress-tolerance of rice.The transgenic plants with overexpressing or heterologous high levels of Poaceae OsSGL ortholog genes exhibited longer grain size than the wild type plants.Larger cells were seen in panicles of the four transgenic lines with paraffin sectioning and scanning electron microscopy analyses.In addition,four Poaceae OsSGL ortholog genes positively affected the drought tolerance of rice.Four transgenic plants displayed higher resistance to drought stress at the seedling and vegetative stages.RNA-sequencing and qRT-PCR results indicated that over-or heterologous-expression of four Poaceae OsSGL ortholog genes also affected the transcriptome of rice plants.These genes may play a role in auxin and cytokinin biosynthesis and their transduction pathways.Taken together,these results suggested that the four OsSGL orthologs have a conserved function in the regulation of stress-tolerance and cell growth by modulating hormonal biosynthesis and signaling.展开更多
SGLT2 inhibitors improve hyperglycemia with a decline in body weight and blood pressure, the outcomes touted to be of major importance in management of type 2 diabetes. However, the efficacy in lowering glycemia is ve...SGLT2 inhibitors improve hyperglycemia with a decline in body weight and blood pressure, the outcomes touted to be of major importance in management of type 2 diabetes. However, the efficacy in lowering glycemia is very modest and imparts an undue cost burden on patients. Moreover, the declines in body weight and blood pressure are slight at best and orthostatic hypotension and its manifestations including syncope at worst, are all secondary to dehydration and probable total body electrolyte depletion caused by polyuria and nocturia as anticipated and established consequences of glycolsuria induced by SGLT2 inhibitors via their mechanism of action. Moreover, frequent adverse effects including impaired renal function as expressed by rises in serum creatinine and urea nitrogen, hyperkalemia and recurrent genitourinary infections are certainly likely to lead to the decline in quality of life. Finally, a rise in LDL cholesterol accompanied by increased serum viscosity secondary to dehydration may compromise cardiovascular safety as well. Thus, use of these expensive agents with modest efficacy and with established significant pathologic side effects escalating costs even further and unknown long term safety may be contradictory to the tenets of ethical medical practice established by “Hippocratic oath”. Recent approval of SGLT2 inhibitors by regulatory agencies in Europe and USA for treatment of hyperglycemia in type 2 diabetes is therefore surprising and disheartening.展开更多
文摘针对分类问题,本文提出了稀疏组Lasso支持向量机方法(Sparse group lasso SVM,SGLSVM),即在SVM模型的损失函数中引入SGL惩罚函数,能同时进行组间变量和组内变量的筛选。由于SGL-SVM的目标函数求解比较复杂,本文又提出了一种快速的双层坐标下降算法。通过模拟实验,发现SGL-SVM方法在预测效果和变量选择上均要优于其他方法,对于变量具有自然分组结构且组内是稀疏的数据,本文方法在提高变量选择效果的同时又能提高模型的预测精度。最后,本文将SGL-SVM方法应用到我国制造业上市公司财务困境预测中。
基金supported by the National Natural Science Foundation of China(Grant Nos.31501393,31671671 and 31671612)the Open Research Fund of State Key Laboratory of Hybrid Rice(Wuhan University,China)(Grant No.KF201803)。
文摘Grain yield is a polygenic trait that can be influenced by environmental factors and genetic compositions at all plant growth stages.Currently,the molecular mechanisms behind the coordination of the interaction between grain yield-related traits remain unknown.In this study,we characterized the function of four STRESS_tolerance and GRAIN_LENGTH(Os SGL)Poaceae ortholog genes that are transcribed into DUF1645 domain-containing proteins in relation to the grain length,grain weight,and drought stress-tolerance of rice.The transgenic plants with overexpressing or heterologous high levels of Poaceae OsSGL ortholog genes exhibited longer grain size than the wild type plants.Larger cells were seen in panicles of the four transgenic lines with paraffin sectioning and scanning electron microscopy analyses.In addition,four Poaceae OsSGL ortholog genes positively affected the drought tolerance of rice.Four transgenic plants displayed higher resistance to drought stress at the seedling and vegetative stages.RNA-sequencing and qRT-PCR results indicated that over-or heterologous-expression of four Poaceae OsSGL ortholog genes also affected the transcriptome of rice plants.These genes may play a role in auxin and cytokinin biosynthesis and their transduction pathways.Taken together,these results suggested that the four OsSGL orthologs have a conserved function in the regulation of stress-tolerance and cell growth by modulating hormonal biosynthesis and signaling.
文摘SGLT2 inhibitors improve hyperglycemia with a decline in body weight and blood pressure, the outcomes touted to be of major importance in management of type 2 diabetes. However, the efficacy in lowering glycemia is very modest and imparts an undue cost burden on patients. Moreover, the declines in body weight and blood pressure are slight at best and orthostatic hypotension and its manifestations including syncope at worst, are all secondary to dehydration and probable total body electrolyte depletion caused by polyuria and nocturia as anticipated and established consequences of glycolsuria induced by SGLT2 inhibitors via their mechanism of action. Moreover, frequent adverse effects including impaired renal function as expressed by rises in serum creatinine and urea nitrogen, hyperkalemia and recurrent genitourinary infections are certainly likely to lead to the decline in quality of life. Finally, a rise in LDL cholesterol accompanied by increased serum viscosity secondary to dehydration may compromise cardiovascular safety as well. Thus, use of these expensive agents with modest efficacy and with established significant pathologic side effects escalating costs even further and unknown long term safety may be contradictory to the tenets of ethical medical practice established by “Hippocratic oath”. Recent approval of SGLT2 inhibitors by regulatory agencies in Europe and USA for treatment of hyperglycemia in type 2 diabetes is therefore surprising and disheartening.
