Three-dimensional tracking of axonal projections in the brain by magnetic resonance imaging

The relationship between brain structure and complex behavior is governed by large-scale neurocognitive networks. The availability of a noninvasive technique that can visualize the neuronal projections connecting the functional centers should therefore provide new keys to the understanding of brain function. By using high-resolution three-dimensional diffusion magnetic resonance imaging and a newly designed tracking approach, we show that neuronal pathways in the rat brain can be probed in situ. The results are validated through comparison with known anatomical locations of such fibers.     

New insights into positional alcohol nystagmus using three-dimensional eye-movement analysis

BACKGROUND: It is generally accepted that 0 to 4 degreesC is a suitable temperature for organ preservation. The reason for this is based on the premise that at temperatures below 0 degreesC, intracellular ice is likely to form, with subsequent damage to cellular structures. However, it cannot be assumed that subzero temperatures will freeze the cell. In this study, we attempted to confirm the specific freezing point of rat liver and to preserve it at a temperature just above that point. METHODS: Rat livers were stored for 24, 48, 72, and 96 h either at 4 degreesC (Group N) or at -0.8 degreesC (just above the temperature ascertained to be the specific freezing point of rat liver; Group H). After cold storage, the livers were perfused for 60 min using an isolated perfused liver model for assessment of liver function. RESULTS: ATP and TAN (total adenine nucleotides) in reperfused liver tissues were significantly higher in Group H than in Group N for all preservation periods. ADP was significantly higher in Group H than in Group N for 24-, 72-, and 96-h preservation periods. Energy charge was significantly higher in Group H than in Group N for 24-, 48-, and 96-h preservation periods. CONCLUSIONS: Regarding the content of ATP, ADP, and TAN and the adenylate energy charge, our results indicate that preservation at -0.8 degreesC is advantageous. This novel preservation technique seems to prolong the period that organs can be stored.     

Integrating LIDAR data and multispectral imagery for enhanced classification of rangeland vegetation: A meta analysis

This study compared the suitability of LIDAR (LIght Detection And Ranging) data, three-band multispectral data, and LIDAR data integrated with multispectral information, for classifying spatially complex vegetation in the Aspen Parkland of western Canada. Classifications were performed for both a) general vegetation classes limited to three major formations of deciduous forest, shrubland and grassland, and b) eight detailed vegetation classes including upland mixed prairie and fescue grasslands, closed and semi-open aspen forests, western snowberry and silverberry shrublands, and fresh and saline riparian (lowland) meadows. A Digital Elevation Model (DEM) and Surface Elevation Model (SEM) developed from LIDAR data incorporated both topographic and biological biases in community positioning across the landscape. Using multispectral data, the original digital image mosaic, its hybrid color composite, and an intensity-hue-saturation (IHS) image were each tested. Final vegetation classification was done through integration of information from both digital images and LIDAR data to evaluate the improvement in classification accuracy. Among the land cover schedules with three and eight classes of vegetation, classification from the multispectral imagery, specifically the hybrid color composite image, had the highest accuracy, peaking at 74.6% and 59.4%, respectively. In contrast, the LIDAR classification schedules led to an average classification accuracy of 64.8% and 52.3%, respectively, for the general and detailed vegetation data. Subsequent integration of the LIDAR and digital image classification schedules resulted in accuracy improvements of 16 to 20%, resulting in a superior final accuracy of 91% and 80.3%, respectively, for the three and eight classes of vegetation. A final land cover map including 8 classes of vegetation, fresh and saline water, as well as bare ground, was created for the study area with an overall accuracy of 83.9%, highlighting the benefit of integrating LIDAR and multispectral imagery for enhanced vegetation classification in heterogenous rangeland environments.