Objective To focus on the possible mechanism about the spermicidal effect of methanolic extract of leaves of Cestrum parqui （Solanacea） on human spermatozoa. Methods Sperm motility and viability were noted according...Objective To focus on the possible mechanism about the spermicidal effect of methanolic extract of leaves of Cestrum parqui （Solanacea） on human spermatozoa. Methods Sperm motility and viability were noted according to the guideline of WHO. The morphological changes in chromatin materials and in plasma membrane at the head part of the spermatozoa were assessed under transmission electron microscopy （TEM）. DNA fragmentation index （DFI） of spermatozoa in percentage was assessed by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling （TUNEL） using kits. For confirmation of DNA breakage, gel electrophoresis of DNA was conducted using 1.2 % agarose gel. Results Sperm viability and motility were both decreased in dose-dependent manner from 50 to 300 lzg/ml of methanolic extract in respect to the control. Loss of viability and motility both were noted 100% at the dose of 300 #g/ml within 5 min. From the microphotography it has been revealed that chromatin condensation at the dose of 200 lzg/ml is more than the control without any noticeable alteration in plasma membrane. In contrast, chromatin decondensation has been noticed at the dose of 300 I^g/ml along with a remarkable disruption in plasma membrane. Analysis of DNA damage by TUNEL revealed a significant elevation （P〈0.01） in the level of% DFI at the dose of 200 μg/ml （moderate dose） after 17 h in respect to the control. But at the dose of 300 lzg/ml, no significant variation was observed in this parameter upto 24 h of exposure though a significant variation （P〈0.01） was noted after 48 h of exposure compared with the control. Gel electrophoresis of DNA also followed the same type of results i.e. 200 lzg/ml affected DNA integrity but other doses were ineffective in this concern. Conclusion The extract of Cestrum parqui at moderate dose exhibited spermicidal activity by inducing apoptotic pathway but at the high dose it caused necrosis.展开更多
Many forest ecosystems in Kenya are at risk from the invasion of exotic plant species that pose numerous threats like decreasing biodiversity, deteriorating ecosystem processes and degrading their services. They also ...Many forest ecosystems in Kenya are at risk from the invasion of exotic plant species that pose numerous threats like decreasing biodiversity, deteriorating ecosystem processes and degrading their services. They also affect human, other animal health and various angles of the general economy. Cestrum aurantiacum Lindl. is a species with invasive reputation having been reported with very high biological success rating and has been noted in parts of Kenya in proportions that raise concerns. It has negative effects on other plants and animal species function and diversity. These impacts have been recorded in Kenya and elsewhere in this review, I synthesized data from studies that have examined the taxonomy of Cestrum aurantiacum, how this species become part of the ecosystem in Kenya and its ecological and economic impacts. I sourced relevant articles from the internet using keywords relating to the taxonomy, impacts and reports of invasive species and narrowed to records from different parts of Kenya. In this review, I looked across twenty-seven studies, on Cestrum aurantiacum in Kenya and went ahead to review one hundred and thirteen other articles for expanded discussion. Species data in published articles from different parts of Kenya were used as georefences to model overall species distribution which was noted to lie between Mt Kenya, Mt Elgon-Nandi hills and Cherangani hills. It was clearly established that there are major adverse effects associated with species. First, it can change native ecosystem processes such as nutrient cycle or hydrology and contribute significant role on the decrease of native species. A primary risk of Cestrum aurantiacum is that when this species alters the biodiversity, ecosystems are transformed into new configurations with unpredictable consequences to humans and other wildlife in totality. Despite the few positive applications of cestrum species, these can’t compensate for the enormous detrimental consequences associated with the species. Cestrum aurantiacum was introduced in Kenya as an ornamental plant in 1921 by the government and was distributed in several regions of high potential Kenya due to high level of hybridization within the genera, several variables of the species occur. By examining the level of information regarding the taxonomy and impacts of Cestrum aurantiacum on animal and plant species, this study provides pivotal information at the country level with a view to informing monitoring and conservation efforts, such as alien plant removal and control programmes, and ensuring that endemic terrestrial animal and plant diversity are maintained.展开更多
为了准确识别气体绝缘开关柜(gas insulated switchgear,GIS)设备的异常工况,提出了一种基于加权梅尔频率谱系数单类支持向量机(Mel frequency cestrum coefficient-one class support vector machine,MFCC-OCSVM)和贝叶斯优化的门控循...为了准确识别气体绝缘开关柜(gas insulated switchgear,GIS)设备的异常工况,提出了一种基于加权梅尔频率谱系数单类支持向量机(Mel frequency cestrum coefficient-one class support vector machine,MFCC-OCSVM)和贝叶斯优化的门控循环单元(bidirectional gate recurrent unit,BiGRU)声纹识别算法。首先,利用基于F统计量的MFCC对声纹数据进行加权特征提取,突出重要特征并减弱噪声的影响,然后利用OCSVM对加权后的特征进行异常检测并去除异常值,提高数据质量。为解决样本不平衡问题,采用合成少数类过采样技术(synthetic minority over-sampling technique,SMOTE)进行声纹样本的均衡。最后,应用基于贝叶斯优化的BiGRU模型进行声纹识别。以某气体绝缘全封闭组合电器(gas insulated switchgear,GIS)为例,采集了20类不同工况下操纵机构的声音样本,与多种经典分类模型进行对比。结果显示,所提算法取得的最高平均识别准确率达到了92.8%,相比于自适应增强、朴素贝叶斯和线性判别分析算法分别提升了30.1%、14.7%和11.5%。通过消融实验进一步评估和验证了所提算法各个流程对声纹识别的实际效果和性能影响,研究成果可为GIS设备异常工况的声纹识别提供高效技术路线。展开更多
基金financial support in connection with Indo-Tunisia Bilateral Research program
文摘Objective To focus on the possible mechanism about the spermicidal effect of methanolic extract of leaves of Cestrum parqui （Solanacea） on human spermatozoa. Methods Sperm motility and viability were noted according to the guideline of WHO. The morphological changes in chromatin materials and in plasma membrane at the head part of the spermatozoa were assessed under transmission electron microscopy （TEM）. DNA fragmentation index （DFI） of spermatozoa in percentage was assessed by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling （TUNEL） using kits. For confirmation of DNA breakage, gel electrophoresis of DNA was conducted using 1.2 % agarose gel. Results Sperm viability and motility were both decreased in dose-dependent manner from 50 to 300 lzg/ml of methanolic extract in respect to the control. Loss of viability and motility both were noted 100% at the dose of 300 #g/ml within 5 min. From the microphotography it has been revealed that chromatin condensation at the dose of 200 lzg/ml is more than the control without any noticeable alteration in plasma membrane. In contrast, chromatin decondensation has been noticed at the dose of 300 I^g/ml along with a remarkable disruption in plasma membrane. Analysis of DNA damage by TUNEL revealed a significant elevation （P〈0.01） in the level of% DFI at the dose of 200 μg/ml （moderate dose） after 17 h in respect to the control. But at the dose of 300 lzg/ml, no significant variation was observed in this parameter upto 24 h of exposure though a significant variation （P〈0.01） was noted after 48 h of exposure compared with the control. Gel electrophoresis of DNA also followed the same type of results i.e. 200 lzg/ml affected DNA integrity but other doses were ineffective in this concern. Conclusion The extract of Cestrum parqui at moderate dose exhibited spermicidal activity by inducing apoptotic pathway but at the high dose it caused necrosis.
文摘Many forest ecosystems in Kenya are at risk from the invasion of exotic plant species that pose numerous threats like decreasing biodiversity, deteriorating ecosystem processes and degrading their services. They also affect human, other animal health and various angles of the general economy. Cestrum aurantiacum Lindl. is a species with invasive reputation having been reported with very high biological success rating and has been noted in parts of Kenya in proportions that raise concerns. It has negative effects on other plants and animal species function and diversity. These impacts have been recorded in Kenya and elsewhere in this review, I synthesized data from studies that have examined the taxonomy of Cestrum aurantiacum, how this species become part of the ecosystem in Kenya and its ecological and economic impacts. I sourced relevant articles from the internet using keywords relating to the taxonomy, impacts and reports of invasive species and narrowed to records from different parts of Kenya. In this review, I looked across twenty-seven studies, on Cestrum aurantiacum in Kenya and went ahead to review one hundred and thirteen other articles for expanded discussion. Species data in published articles from different parts of Kenya were used as georefences to model overall species distribution which was noted to lie between Mt Kenya, Mt Elgon-Nandi hills and Cherangani hills. It was clearly established that there are major adverse effects associated with species. First, it can change native ecosystem processes such as nutrient cycle or hydrology and contribute significant role on the decrease of native species. A primary risk of Cestrum aurantiacum is that when this species alters the biodiversity, ecosystems are transformed into new configurations with unpredictable consequences to humans and other wildlife in totality. Despite the few positive applications of cestrum species, these can’t compensate for the enormous detrimental consequences associated with the species. Cestrum aurantiacum was introduced in Kenya as an ornamental plant in 1921 by the government and was distributed in several regions of high potential Kenya due to high level of hybridization within the genera, several variables of the species occur. By examining the level of information regarding the taxonomy and impacts of Cestrum aurantiacum on animal and plant species, this study provides pivotal information at the country level with a view to informing monitoring and conservation efforts, such as alien plant removal and control programmes, and ensuring that endemic terrestrial animal and plant diversity are maintained.
