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The fermentation of dehydroepiandrosterone synthesized from the starting material diosgenin using Mucor racemosus produced 7alpha-hydroxy-dehydroepiandrosterone and 7beta-hydroxy-dehydroepiandrosterone. The bioactivity of the microbial metabolites is also discussed. The species M. racemosus was isolated by screening among stains from soil samples collected(More)
Fermentation of 5alpha,6alpha-epoxy-3beta-hydroxy-16-pregnen-20-one (4) with Trichoderma viride under aerobic condition yielded 3beta,5alpha,6beta-trihydroxy-16-pregnen-20-one (5) and 3beta,5alpha,6beta,15beta-tetrahydroxy-16-pregnen-20-one (6). Each microbial metabolite was characterized by spectroscopic methods. Compounds 6 and(More)
The biotransformations of a series of steroids by the fungus penicillium citreo-viride A.C.C.C. 0402 have been investigated, and the conversion to the same product testolactone (1) was observed from progesterone (2), dehydroepiandrosterone (3), 4-androstene-3, 17-dione (4), 5-androstene-3, 17-diol (5) with the exception of pregnenolone (6) and(More)
It has always been very difficult to recognize realistic actions from unconstrained videos because there are tremendous variations from camera motion, background clutter, object appearance and so on. In this paper, a Single-Feature Hierarchical Latent Dirichlet Allocation model called SF-HLDA by extending Latent Dirichlet Allocation to the hierarchical one(More)
A novel method based on space-time image features is proposed for automatic behavior modeling and recognition. The method is composed of the following three steps: (1). Video sequences are converted into a space-time image, and the image is divided into equal length segments; (2). From these segments, an unsupervised technique based on Dynamic Time Warping(More)
Increasing demand for natural rubber prompts studies into the mechanisms governing the productivity of rubber tree (Heveabrasiliensis). It is very interesting to notice that a rubber tree of clone PR107 in Yunnan, China is reported to yield more than 20 times higher than the average rubber tree. This super-high-yielding (SHY) rubber tree (designated as(More)
We report a systematic investigation of both three-photon absorption (3PA) spectra and wavelength dispersions of Kerr-type nonlinear refraction in wide-gap semiconductors. The Z-scan measurements are recorded for both ZnO and ZnS with femtosecond laser pulses. While the wavelength dispersions of the Kerr nonlinearity are in agreement with a two-band model,(More)
Most approaches for image retrieval are based on the bag-of-visual-word (BoV) representation. However, the BoV model typically ignores the spatial information that is crucial for visual representation. Zhang, et al. [1] proposed an approach to encode spatial information into Bo V using Geometry-preserving Visual Phrases (GVP). They found 2-GVP gives the(More)