A comparison study was made for the characteristics of pH value, orga nic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larc...A comparison study was made for the characteristics of pH value, orga nic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larch and in bulk soils. The results show that the pH values of rhizosphere soil for all the plant ations except the pure walnut stand, which was slightly higher, were lower than those of bulk soils, while the organic matter contents in the rhizosphere soil f or all the plantations except the mixed plantation, which was slightly lower, we re higher than that in bulk soil. There exists a relative nitrogen accumulation in the rhizosphere and the extent to which the nitrogen accumulates is closely r elated to tree species and mixed pattern. As far as the total P and K contents a re considered, there exists a deficient tendency in rhizosphere in comparison wi th bulk soil. The element N, P and K are all mobilized in the rhizosphere of the pure or mixed plantation, characterized by the higher contents of the available N, P and K in the rhizosphere. The available N content in the rhizosphere of th e larch in mixed plantation was obviously higher than that of its pure plantatio n, whereas the available P and K contents in the rhizosphere of walnut in the mi xed plantation, on the other hand, were significantly higher than those of its p ure plantation.展开更多
Literate individuals possess knowledge and skill and can apply these to perform tasks in novel settings. Knowledge is at the heart of physical literacy and provides the foundation for knowing what to do and how and wh...Literate individuals possess knowledge and skill and can apply these to perform tasks in novel settings. Knowledge is at the heart of physical literacy and provides the foundation for knowing what to do and how and when to perform. In this paper I argue that physical literacy includes not only knowledge for performance but also the ability to apply knowledge and use knowledge for innovation. Scholars since the 1930s have addressed the role of knowledge in physical literacy designing curricula centered on transmitting knowledge through a range of interdisciplinary approaches to physical education. This emphasis on physical literacy curricula continues today in the Science, PE, ＆ Me.t and The Science of Healthful Living interdisciplinary curricula.展开更多
Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixt...Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixty male Sprague-Dawley rats were divided equally into two groups: GDNF group and control group. The SCI model was established according to the method of Nystrom, and then the DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA complexes were injected into the injured spinal cord. The expression of GDNF cDNA 1 week after injection was detected by RT-PCR and fluorescence microscope. We observed the remaining motoneurons in the anterior horn and the changes of cholinesterase (CHE) and acid phosphatase (ACP) activity using Nissl and enzyme histochemistry staining. The locomotion function of hind limbs of rats was evaluated using inclined plane test and BBB locomotor scale. Results: RT-PCR and fluorescence observation confirmed the presence of expression of GDNF cDNA 1 week and 4 weeks after injection. At 1, 2, 4 weeks after SCI, the number of motoneurons in the anterior horn in GDNF group ((20.4)±(3.2), (21.7)±(3.6), (22.5)±(3.4)) was more than that in control group ((16.8)±(2.8), (17.3)±(2.7), (18.2)±(3.2), P<(0.05)). At 1, 2 weeks after SCI, the mean gray of the CHE-stained spinal motoneurons in GDNF group ((74.2)±(25.8), (98.7)±(31.6)) was less than that in control group ((98.5)±(32.2), (134.6)±(45.2), P<(0.01)), and the mean gray of ACP in GDNF group ((84.5)±(32.6), (79.5)±(28.4)) was more than that in control group ((61.2)±(24.9), (52.6)±(19.9), P<(0.01)). The locomotion functional scales in GDNF group were higher than that in control group within 1 to 4 weeks after SCI (P<(0.05)). Conclusions: GDNF gene transfer in vivo can protect motoneurons from death and degeneration induced by incompleted spinal cord injury as well as enhance locomotion functional restoration of hind limbs. These results suggest that liposome-mediated delivery of GDNF cDNA might be a practical method for treating traumatic spinal cord injury.展开更多
基金Hundred Scientists" Project of Ch inese Academy of Sciences.
文摘A comparison study was made for the characteristics of pH value, orga nic matter content, nutrient element N, P and K contents in rhizosphere soils of pure and mixed plantations of Manchurian walnut and Dahurian larch and in bulk soils. The results show that the pH values of rhizosphere soil for all the plant ations except the pure walnut stand, which was slightly higher, were lower than those of bulk soils, while the organic matter contents in the rhizosphere soil f or all the plantations except the mixed plantation, which was slightly lower, we re higher than that in bulk soil. There exists a relative nitrogen accumulation in the rhizosphere and the extent to which the nitrogen accumulates is closely r elated to tree species and mixed pattern. As far as the total P and K contents a re considered, there exists a deficient tendency in rhizosphere in comparison wi th bulk soil. The element N, P and K are all mobilized in the rhizosphere of the pure or mixed plantation, characterized by the higher contents of the available N, P and K in the rhizosphere. The available N content in the rhizosphere of th e larch in mixed plantation was obviously higher than that of its pure plantatio n, whereas the available P and K contents in the rhizosphere of walnut in the mi xed plantation, on the other hand, were significantly higher than those of its p ure plantation.
文摘Literate individuals possess knowledge and skill and can apply these to perform tasks in novel settings. Knowledge is at the heart of physical literacy and provides the foundation for knowing what to do and how and when to perform. In this paper I argue that physical literacy includes not only knowledge for performance but also the ability to apply knowledge and use knowledge for innovation. Scholars since the 1930s have addressed the role of knowledge in physical literacy designing curricula centered on transmitting knowledge through a range of interdisciplinary approaches to physical education. This emphasis on physical literacy curricula continues today in the Science, PE, ＆ Me.t and The Science of Healthful Living interdisciplinary curricula.
文摘Objective: To investigate the effect of liposome-mediated glial cell line-derived neurotrophic factor (GDNF) gene transfer in vivo on spinal cord motoneurons after spinal cord injury (SCI) in adult rats. Methods: Sixty male Sprague-Dawley rats were divided equally into two groups: GDNF group and control group. The SCI model was established according to the method of Nystrom, and then the DC-Chol liposomes and recombinant plasmid pEGFP-GDNF cDNA complexes were injected into the injured spinal cord. The expression of GDNF cDNA 1 week after injection was detected by RT-PCR and fluorescence microscope. We observed the remaining motoneurons in the anterior horn and the changes of cholinesterase (CHE) and acid phosphatase (ACP) activity using Nissl and enzyme histochemistry staining. The locomotion function of hind limbs of rats was evaluated using inclined plane test and BBB locomotor scale. Results: RT-PCR and fluorescence observation confirmed the presence of expression of GDNF cDNA 1 week and 4 weeks after injection. At 1, 2, 4 weeks after SCI, the number of motoneurons in the anterior horn in GDNF group ((20.4)±(3.2), (21.7)±(3.6), (22.5)±(3.4)) was more than that in control group ((16.8)±(2.8), (17.3)±(2.7), (18.2)±(3.2), P<(0.05)). At 1, 2 weeks after SCI, the mean gray of the CHE-stained spinal motoneurons in GDNF group ((74.2)±(25.8), (98.7)±(31.6)) was less than that in control group ((98.5)±(32.2), (134.6)±(45.2), P<(0.01)), and the mean gray of ACP in GDNF group ((84.5)±(32.6), (79.5)±(28.4)) was more than that in control group ((61.2)±(24.9), (52.6)±(19.9), P<(0.01)). The locomotion functional scales in GDNF group were higher than that in control group within 1 to 4 weeks after SCI (P<(0.05)). Conclusions: GDNF gene transfer in vivo can protect motoneurons from death and degeneration induced by incompleted spinal cord injury as well as enhance locomotion functional restoration of hind limbs. These results suggest that liposome-mediated delivery of GDNF cDNA might be a practical method for treating traumatic spinal cord injury.
