Accurate detection of moving objects is an important step in stable tracking or recognition. By using a nonparametric density estimation method over a joint domain-range representation of image pixels, the correlation...Accurate detection of moving objects is an important step in stable tracking or recognition. By using a nonparametric density estimation method over a joint domain-range representation of image pixels, the correlation between neighboring pixels can be used to achieve high levels of detection accuracy in the presence of dynamic background. However, color similarity between foreground and background will cause many foreground pixels to be misclassified. In this paper, an adaptive foreground model is exploited to detect moving objects in dynamic scenes. The foreground model provides an effective description of foreground by adaptively combining the temporal persistence and spatial coherence of moving objects. Building on the advantages of MAP-MRF (the maximum a posteriori in the Markov random field) decision framework, the proposed method performs well in addressing the challenging problem of missed detection caused by similarity in color between foreground and background pixels. Experimental results on real dynamic scenes show that the proposed method is robust and efficient.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Project (Nos 60602012 and 60675023) supported by the National Natural Science Foundation of Chinathe National High-Tech Re-search and Development Program (863) of China (No 2007AA01Z 164)the Shanghai Key Laboratory Opening Plan Grant (No.06dz22103),China
文摘Accurate detection of moving objects is an important step in stable tracking or recognition. By using a nonparametric density estimation method over a joint domain-range representation of image pixels, the correlation between neighboring pixels can be used to achieve high levels of detection accuracy in the presence of dynamic background. However, color similarity between foreground and background will cause many foreground pixels to be misclassified. In this paper, an adaptive foreground model is exploited to detect moving objects in dynamic scenes. The foreground model provides an effective description of foreground by adaptively combining the temporal persistence and spatial coherence of moving objects. Building on the advantages of MAP-MRF (the maximum a posteriori in the Markov random field) decision framework, the proposed method performs well in addressing the challenging problem of missed detection caused by similarity in color between foreground and background pixels. Experimental results on real dynamic scenes show that the proposed method is robust and efficient.
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.
