Reinnervation of dentate gyrus by homologous afferents following entorhinal cortical lesions in adult rats

Granule cells of the rat dentate gyrus which are denervated by unilateral destruction of the entorhinal cortex are reinnervated in part by proliferation of surviving pathways from the contralateral entorhinal cortex. The cells of origin of these lesion-induced projections were identified by retrograde labeling with horseradish peroxidase and were the same cell type which normally project to the ipsilateral dentate gyrus     

Hyperspectral remote sensing for shallow waters. 2. Deriving bottom depths and water properties by optimization

In earlier studies of passive remote sensing of shallow-water bathymetry, bottom depths were usually derived by empirical regression. This approach provides rapid data processing, but it requires knowledge of a few true depths for the regression parameters to be determined, and it cannot reveal in-water constituents. In this study a newly developed hyperspectral, remote-sensing reflectance model for shallow water is applied to data from computer simulations and field measurements. In the process, a remote-sensing reflectance spectrum is modeled by a set of values of absorption, backscattering, bottom albedo, and bottom depth; then it is compared with the spectrum from measurements. The difference between the two spectral curves is minimized by adjusting the model values in a predictor-corrector scheme. No information in addition to the measured reflectance is required. When the difference reaches a minimum, or the set of variables is optimized, absorption coefficients and bottom depths along with other properties are derived simultaneously. For computer-simulated data at a wind speed of 5 m/s the retrieval error was 5.3% for depths ranging from 2.0 to 20.0 m and 7.0% for total absorption coefficients at 440 nm ranging from 0.04 to 0.24 m(-1). At a wind speed of 10 m/s the errors were 5.1% for depth and 6.3% for total absorption at 440 nm. For field data with depths ranging from 0.8 to 25.0 m the difference was 10.9% (R(2) = 0.96, N = 37) between inversion-derived and field-measured depth values and just 8.1% (N = 33) for depths greater than 2.0 m. These results suggest that the model and the method used in this study, which do not require in situ calibration measurements, perform very well in retrieving in-water optical properties and bottom depths from above-surface hyperspectral measurements.     

Adopting a modern ecological view of the metropolitan landscape: the case of a greenspace system for the New York City region

Concern about environmental quality and the long-term livability of urban areas is now a driving paradigm for planning professionals. Although a modern ecological framework exists, inappropriate or outdated concepts continue to be used in the context of land-use decision making. These classical concepts emphasize a static view of the landscape and focus on short term planing of single sites. The modern framework emphasizes a dynamic view of a biologically rich urban environment with a focus on interactions among multiple sites across temporal scales. We summarize this framework by presenting five key ecological principles—content, context, dynamics, heterogeneity and hierarchy—and use the New York City Metropolitan Area as a case study to illustrate how these principles might be applied to achieve specific planning goals. We additionally use the case study as reference in providing some guidelines to more effectively incorporate the modern ecological framework in future planning.