We review investigations that have lead to a model of how the ventral spinal cord of higher vertebrate embryos is patterned during development. Central to this model is the secreted morphogen protein, Sonic hedgehog. There is now considerable evidence that this molecule acts in a concentration-dependent manner to direct the development of the spinal cord. Recent studies have suggested that two ...

Germ cell formation in Drosophila relies on polar granules, which are large ribonucleoprotein complexes found at the posterior end of the embryo. The granules undergo characteristic changes in morphology during development, including the assembly of multiple spherical bodies from smaller precursors. Several polar granule components, both protein and RNA, have been identified. One of these, the ...

A zebra-crossing detection method for intelligent vehicle is proposed in this paper. The method is performed on a bird-eye view image called inverse perspective mapping image. The complete method includes two phrases. First, a morphological filer followed by horizontal projection is applied to fast extract candidate zebra-crossing regions, where the size and structure information of zebra-cross...

The vertebrate organizer has been of intense interest since its discovery in amphibia by Spemann and Mangold in the early 1920s (Ref. 1). The organizer was operationally defined as a piece of tissue that can induce a duplicated dorsal body axis and head when transplanted into the ventral side of a host embryo. The original Spemann and Mangold organizer experiment provided the first convincing d...

Methylation of lysine 27 on histone H3 (H3K27me) by the Polycomb complex (PRC2) proteins is associated with gene silencing in many developmental processes. A cluster of recent papers (Agger et al., 2007; De Santa et al., 2007; Lan et al., 2007; Lee et al., 2007) identify the JmjC-domain proteins UTX and JMJD3 as H3K27-specific demethylases that remove this methyl mark, enabling the activation o...

In Dynamic Electronic Speckle Pattern Interferometry (DESPI), deformation analysis could be done for successively acquired frame data of interfering speckle patterns with no additional frames like phase shifting speckle patterns. Our final goal is to obtain a temporally varying process of two-dimensional strain field. Two normal strains and shearing strain are derived by numerical derivatives o...

Translational regulation plays a prominent role in Drosophila body patterning. Progress in elucidating the underlying mechanisms has been limited by the lack of a homologous in vitro system that supports regulation. Here we show that extracts prepared from Drosophila tissues are competent for translation. Ovarian extracts, but not embryonic extracts, support the Bruno response element- and Brun...

An electroencephalogram (EEG) signal is extremely nonstationary, highly composite and very complex, all of which reflects the underlying integral neurodynamics. Understanding the EEG "grammar", its internal structural organization would place a "Rozetta stone" in researchers' hands, allowing them to more adequately describe the information processes of the brain in terms of EEG phenomenology. T...

Plant architecture results from the activity of the shoot apical meristem, which initiates leaves, internodes, and axillary meristems. KNOTTED1-like homeobox (KNOX) genes are expressed in specific patterns in the shoot apical meristem and play important roles in plant architecture. KNOX proteins interact with BEL1-like (BELL) homeodomain proteins and together bind a target sequence with high af...