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Six new species of Tricholoma (Fr.) Staude in sections Genuina (Tricholoma amarissimum, Tricholoma lutescentifolium, Tricholoma pudorinum, Tricholoma sapineum) and Fucata (Tricholoma griseobrunneum, Tricholoma pallidogriseum) are formally described from North America east of the Rocky Mountains based on their nrITS sequence, morphology, ecology, and distribution patterns. Those species are found in summer or fall in deciduous or coniferous forests. Descriptions of their morphological characters are provided, along with photographs of the basidiomata and their micromorphology. The new species are compared with similar species occurring in North America and Europe. Tricholoma felschii Ovrebo, Hughes & Halling, in section Fucata, is here considered to represent three species, T. felschii s. str., Tricholoma subumbrinum A.H. Sm., and the newly described T. griseobrunneum. Emended descriptions of the first two species are provided to accommodate the new concepts. [ABSTRACT FROM AUTHOR]

A new method, called genetic programming-spectral vegetation index (GP-SVI), for the extraction of information from hyperspectral data is presented. This method is introduced in the context of precision farming. GP-SVI derives a regression model describing a specific crop biophysical variable from hyperspectral images (verified with in situ observations). GP-SVI performed better than other methods [multiple regression, tree-based modeling, and genetic algorithm-partial least squares (GA-PLS)] on the task of correlating canopy ultrogen content in a cornfield with pixel reflectance. It is also shown that the band selection performed by GP-SVI is comparable with the selection performed by GA-PLS, a method that is specifically designed to deal with hyperspectral data. Index Terms--Compact Airborne Spectrographic Imager (CASI) sensor, crop nitrogen, feature selection, genetic programming (GP), hyperspectral remote sensing, precision farming, site-specific management, spectral vegetation indices (SVIs).

Meloche, Sylvain, Jacques Landry, Jacques Huot, Francois Houle, Francois Marceau, and Edith Giasson. p38 MAP kinase pathway regulates angiotensin II-induced contraction of rat vascular smooth muscle. Am J Physiol Heart Circ Physiol 279: H741-H751, 2000.--Angiotensin II (ANG II) is a multifunctional hormone that exerts potent vasoconstrictor and hypertrophic effects on vascular smooth muscle. Here, we demonstrate that the p38 mitogen-activated protein (MAP) kinase pathway is involved in ANG II-induced vascular contraction. Addition of ANG II to rat aortic smooth muscle cells (SMC) caused a rapid and transient increase of p38 activity through activation of the [AT.sub.1] receptor subtype. This response to ANG II was strongly attenuated by pretreating cells with antioxidants and diphenylene iodonium and was mimicked by exposure of cells to [H.sub.2][O.sub.2]. Stimulation of p38 by ANG II resulted in the enzymatic activation of MAP kinase-activated protein (MAPKAP) kinase-2 and the phosphorylation of heat shock protein 27 (HSP27) in aortic SMC. Pretreatment of cells with the specific p38 MAP kinase inhibitor SB-203580 completely blocked the ANG II-dependent activation of MAPKAP kinase-2 and phosphorylation of HSP27. ANG II also caused a robust activation of MAPKAP kinase-2 in the intact rat aorta. Incubation with SB-203580 significantly decreased the potency of ANG II to induce contraction of rat aortic rings and depressed the maximal hormone response. These results suggest that the p38 MAP kinase pathway selectively modulates the vasoconstrictor action of ANG II in vascular smooth muscle. smooth muscle cell; signal transduction; mitogen-activated protein kinase; angiotensin receptor