The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Ni...The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Nicotiana tabacum L. cv. Xanthi (nn, Smith)) leaf disks. We compared the effect of temperatures ranging from 15°C, 18°C, 20°C, 22°C to 25°C on the stable expression of β-glucuronidase (GUS) activity of 14 days old hygromycin-selected leaf disks, and on the increase in the fresh weight yield of 28 days old kanamycin-selected calli. The highest average of GUS activity was obtained at 20°C among the five temperatures tested although the difference between the 18°C and 20°C treatment was not statistically significant. The GUS activity at 15°C was statistically lower than those at 18°C and 20°C. The GUS activity in 22°C treatment was an intermediate between the highest (18/20°C) and second highest averages (15°C), and was not statistically significantly different. The lowest average of GUS activity was observed at 25°C. The highest increase in the plate average of fresh weight yield was obtained at 20°C among the five temperature tested. The 20°C treatment was statistically significantly better than the 15°C and 18°C treatments. The 20°C co-cultivation treatment resulted in the higher FW yield than 22°C and 25°C even though the differences were not statistically significant. In conclusion, low co-cultivation temperature at 20°C resulted in the reproducible maximum increase in both the fresh weight yield and stable expression of GUS activity after transformation of tobacco leaf disks.展开更多
Principle Component Analysis (PCA) a widely used mathematical tool for high dimension data analysis. PCA has been used for face recognition[1], motion analysis and synthesis[2], clusterin[3], dimension reduction[4], e...Principle Component Analysis (PCA) a widely used mathematical tool for high dimension data analysis. PCA has been used for face recognition[1], motion analysis and synthesis[2], clusterin[3], dimension reduction[4], etc. PCA provides a guideline for how to reduce a complex dataset to one of lower dimensionality to reveal any hidden, simplified structures that may underlie it.展开更多
Ghrelin was isolated as an endogenous ligand for the GH secretagogue receptor from the rat stomach. Although physiological effects of ghrelin have been revealed by numerous studies, the regulation of stomach ghrelin r...Ghrelin was isolated as an endogenous ligand for the GH secretagogue receptor from the rat stomach. Although physiological effects of ghrelin have been revealed by numerous studies, the regulation of stomach ghrelin remains obscure, and the factor that directly regulates ghrelin expression and production has not been identified. Here, we show some data regarding the characteristic features of ghrelin cells and the regulation of stomach ghrelin. In the gastrointestinal tract, ghrelin cells were identified as opened- and closed-type cells, and it was found that the number of ghrelin cells decreased from the stomach to the colon. The postnatal change in number of ghrelin cells in the stomach showed a sexually dimorphic pattern, indicating a role of estrogen in the regulation of stomach ghrelin. In vitro studies revealed that estrogen stimulated both ghrelin expression and production and that treatment with formestane, an aromatase (estrogen synthetase) inhibitor, decreased ghrelin expression level. On the other hand, leptin was found to inhibit both basal and estrogen-stimulated ghrelin expression. Moreover, both aromatase mRNA- expressing cells and leptin cells were found to be located close to ghrelin cells in the gastric mucosa. Furthermore, we found an inverse relationship between gastric ghrelin and leptin levels in a fasting state, and we revealed relative changes in expression of gastric ghrelin, estrogen and leptin in the postnatal rats. We propose that gastric estrogen and leptin directly regulate stomach ghrelin and that the balance control through gastric estrogen and leptin contributes to the altered ghrelin expression level in some physiological states.展开更多
With rising population,decline in soil productivity and land-based conflicts,the per-capita land availability for cultivation is rapidly decreasing within Benue State,a largely agrarian and small-holder setting.This s...With rising population,decline in soil productivity and land-based conflicts,the per-capita land availability for cultivation is rapidly decreasing within Benue State,a largely agrarian and small-holder setting.This study attempts a local-level support for the actualisation of Sustainable Development Goal Number 2(“end hunger,achieve food security and improved nutrition,and promote sustainable agriculture”)by 2030.Using Multi-Criteria Decision Making(MCDM)method,remote sensing data from Climate Research Unit(CRU)and in-situ data from Nigeria Meteorological Agency(NIMET)were analyzed by GIS techniques to map the suitability of rice cultivation in the study area,with the integration of Normalized Difference Vegetation Index(NDVI),land cover,slope,temperature,precipitation and soil parameters(cation exchange capacity,pH,bulk density,organic carbon).We apply the various statistical parameters that include mean spatial NDVI;correlation coefficient,standard deviation and Root Mean Square(RMS)between CRU and NIMET data.Spatial regression trend analysis is conducted between CRU precipitation and NDVI and between CRU temperature and NDVI from 1985 to 2015.The results reveal that NDVI in highly suitable rice planting regions is higher than marginally suitable regions except in the months of October and November,which shows that the highly suitable regions will yield better than the marginally suitable regions during the dry season.Additionally,NDVI is seasonally bimodal in response to precipitation,meaning that vegetation vigor is more dependent on precipitation than temperature.Finally,the correlation coefficient,standard deviation and RMS between CRU and NIMET precipitation data shows 0.42,108,and 110,respectively,while these three factors between CRU and NIMET temperature data shows 0.88,1.60,and 0.86,respectively.In conclusion,the MCDM approach reveals that upland is more suitable for rice cultivation in Benue State when comparing with the area provided by the Global Land Cover and National Mappings Organization(GLCNMO)data.展开更多
活的非可培养(viable but non cultivable,VBNC)状态是某些细菌在不良环境胁迫下的一种生存策略,在一定的条件下,进入VBNC状态的细菌可以复苏,重新恢复可培养的能力,致病菌也会恢复其致病性。由于微生物培养法和常规分子生物学手段都无...活的非可培养(viable but non cultivable,VBNC)状态是某些细菌在不良环境胁迫下的一种生存策略,在一定的条件下,进入VBNC状态的细菌可以复苏,重新恢复可培养的能力,致病菌也会恢复其致病性。由于微生物培养法和常规分子生物学手段都无法检测到VBNC状态细菌,因此容易对食品安全和公共卫生造成潜在威胁。本文首先简要阐述了VBNC状态细菌的最新研究进展,揭露出VBNC状态细菌的风险和威胁;其次系统介绍了VBNC状态细菌的形成和复苏机制,重点总结了在水、乳制品和肉制品这3种基质中自然存在的细菌被诱导进入VBNC状态细菌的条件,以及VBNC状态细菌复苏的条件和方法。了解细菌在水和食品基质中进入VBNC状态的条件范围能够指导食品加工处理过程中如何避免VBNC状态细菌的产生,对于水和食品的安全风险防控具有重要意义。展开更多
文摘The importance of controlled temperature during the four-days co-cultivation period was evaluated under the most physiologically relevant conditions for Agrobacterium tumefaciens-mediated transformation of tobacco (Nicotiana tabacum L. cv. Xanthi (nn, Smith)) leaf disks. We compared the effect of temperatures ranging from 15°C, 18°C, 20°C, 22°C to 25°C on the stable expression of β-glucuronidase (GUS) activity of 14 days old hygromycin-selected leaf disks, and on the increase in the fresh weight yield of 28 days old kanamycin-selected calli. The highest average of GUS activity was obtained at 20°C among the five temperatures tested although the difference between the 18°C and 20°C treatment was not statistically significant. The GUS activity at 15°C was statistically lower than those at 18°C and 20°C. The GUS activity in 22°C treatment was an intermediate between the highest (18/20°C) and second highest averages (15°C), and was not statistically significantly different. The lowest average of GUS activity was observed at 25°C. The highest increase in the plate average of fresh weight yield was obtained at 20°C among the five temperature tested. The 20°C treatment was statistically significantly better than the 15°C and 18°C treatments. The 20°C co-cultivation treatment resulted in the higher FW yield than 22°C and 25°C even though the differences were not statistically significant. In conclusion, low co-cultivation temperature at 20°C resulted in the reproducible maximum increase in both the fresh weight yield and stable expression of GUS activity after transformation of tobacco leaf disks.
文摘Principle Component Analysis (PCA) a widely used mathematical tool for high dimension data analysis. PCA has been used for face recognition[1], motion analysis and synthesis[2], clusterin[3], dimension reduction[4], etc. PCA provides a guideline for how to reduce a complex dataset to one of lower dimensionality to reveal any hidden, simplified structures that may underlie it.
基金Supported by (in part) Grants for research fellowships from the Japan Society for the Promotion of Science for Young Scientists by the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation (NIBIO)
文摘Ghrelin was isolated as an endogenous ligand for the GH secretagogue receptor from the rat stomach. Although physiological effects of ghrelin have been revealed by numerous studies, the regulation of stomach ghrelin remains obscure, and the factor that directly regulates ghrelin expression and production has not been identified. Here, we show some data regarding the characteristic features of ghrelin cells and the regulation of stomach ghrelin. In the gastrointestinal tract, ghrelin cells were identified as opened- and closed-type cells, and it was found that the number of ghrelin cells decreased from the stomach to the colon. The postnatal change in number of ghrelin cells in the stomach showed a sexually dimorphic pattern, indicating a role of estrogen in the regulation of stomach ghrelin. In vitro studies revealed that estrogen stimulated both ghrelin expression and production and that treatment with formestane, an aromatase (estrogen synthetase) inhibitor, decreased ghrelin expression level. On the other hand, leptin was found to inhibit both basal and estrogen-stimulated ghrelin expression. Moreover, both aromatase mRNA- expressing cells and leptin cells were found to be located close to ghrelin cells in the gastric mucosa. Furthermore, we found an inverse relationship between gastric ghrelin and leptin levels in a fasting state, and we revealed relative changes in expression of gastric ghrelin, estrogen and leptin in the postnatal rats. We propose that gastric estrogen and leptin directly regulate stomach ghrelin and that the balance control through gastric estrogen and leptin contributes to the altered ghrelin expression level in some physiological states.
文摘With rising population,decline in soil productivity and land-based conflicts,the per-capita land availability for cultivation is rapidly decreasing within Benue State,a largely agrarian and small-holder setting.This study attempts a local-level support for the actualisation of Sustainable Development Goal Number 2(“end hunger,achieve food security and improved nutrition,and promote sustainable agriculture”)by 2030.Using Multi-Criteria Decision Making(MCDM)method,remote sensing data from Climate Research Unit(CRU)and in-situ data from Nigeria Meteorological Agency(NIMET)were analyzed by GIS techniques to map the suitability of rice cultivation in the study area,with the integration of Normalized Difference Vegetation Index(NDVI),land cover,slope,temperature,precipitation and soil parameters(cation exchange capacity,pH,bulk density,organic carbon).We apply the various statistical parameters that include mean spatial NDVI;correlation coefficient,standard deviation and Root Mean Square(RMS)between CRU and NIMET data.Spatial regression trend analysis is conducted between CRU precipitation and NDVI and between CRU temperature and NDVI from 1985 to 2015.The results reveal that NDVI in highly suitable rice planting regions is higher than marginally suitable regions except in the months of October and November,which shows that the highly suitable regions will yield better than the marginally suitable regions during the dry season.Additionally,NDVI is seasonally bimodal in response to precipitation,meaning that vegetation vigor is more dependent on precipitation than temperature.Finally,the correlation coefficient,standard deviation and RMS between CRU and NIMET precipitation data shows 0.42,108,and 110,respectively,while these three factors between CRU and NIMET temperature data shows 0.88,1.60,and 0.86,respectively.In conclusion,the MCDM approach reveals that upland is more suitable for rice cultivation in Benue State when comparing with the area provided by the Global Land Cover and National Mappings Organization(GLCNMO)data.
文摘活的非可培养(viable but non cultivable,VBNC)状态是某些细菌在不良环境胁迫下的一种生存策略,在一定的条件下,进入VBNC状态的细菌可以复苏,重新恢复可培养的能力,致病菌也会恢复其致病性。由于微生物培养法和常规分子生物学手段都无法检测到VBNC状态细菌,因此容易对食品安全和公共卫生造成潜在威胁。本文首先简要阐述了VBNC状态细菌的最新研究进展,揭露出VBNC状态细菌的风险和威胁;其次系统介绍了VBNC状态细菌的形成和复苏机制,重点总结了在水、乳制品和肉制品这3种基质中自然存在的细菌被诱导进入VBNC状态细菌的条件,以及VBNC状态细菌复苏的条件和方法。了解细菌在水和食品基质中进入VBNC状态的条件范围能够指导食品加工处理过程中如何避免VBNC状态细菌的产生,对于水和食品的安全风险防控具有重要意义。
