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A myriad of design rules for what constitutes a "good" colormap can be found in the literature. Some common rules include order, uniformity, and high discriminative power. However, the meaning of many of these terms is often ambiguous or open to interpretation. At times, different authors may use the same term to describe different concepts or the same rule is described by varying nomenclature. These ambiguities stand in the way of collaborative work, the design of experiments to assess the characteristics of colormaps, and automated colormap generation. In this paper, we review current and historical guidelines for colormap design. We propose a specified taxonomy and provide unambiguous mathematical definitions for the most common design rules.

Children and youth with disabilities have historically received unequal treatment in the public education system. In the early 20th century, the enactment of compulsory attendance laws in the states began to change the educational opportunities for these students. Opportunities for admittance to public schools were greater, but many students nevertheless did not receive an effective or appropriate education. Beginning in the late 1960s and early 1970s, parents and advocates for students with disabilities began to use the courts in an attempt to force states to provide an equal educational opportunity for these students. These efforts were very successful and eventually led to the passage of federal legislation to ensure these rights. The purpose of this article is to examine the legal history of special education. We will examine these early efforts to ensure a free appropriate education for students with disabilities up to and including the enactment of the Individuals with Disabilities Education Act Amendments of 1997.

3-Hydroxy-3-methylglutaryl-CoA reductase (NADPH) was solubilized with polyoxyethylene ether (Brij) W-1 from a heavy-membrane fraction, sedimented at 16000 x g from a cell-free homogenate of four-day-old, darkgrown radish seedlings (Raphanus sativus L.). Approximately 350-fold purification of the solubilized enzyme activity was achieved by (NH4)2S04 precipitation followed by column chromatography on DEAE-Sephadex A-50, blue-dextran-agarose and HMG-CoA-hexane-agarose. The presence of detergent, which was required at all times to maintain activity, did not interfere with the chromatographic procedures used. Sucrose density centrifugation suggested an apparent molecular mass of 180 kDa with subunits of 45 kDa (polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate). The enzyme was stable at 67.5T for 30 min in the presence of glycerol, dithioerythritol and detergent. Studies of enzyme stability and activation indicate that the enzyme is a hydrophobic protein with free thiol groups that are essential for full activity. The activation energy was estimated to be 92 kJ (Arrhenius plot). Antibodies raised against rat liver and yeast hydroxymethylglutarylCoA (HMG-CoA) reductase failed to bind or inactivate the radish enzyme. When both HMG-CoA and NADPH concentrations were varied, intersecting patterns were obtained with double-reciprocal plots. The apparent K,,, values determined in this way are 1.5 pM [(S)-HMG-CoA], and 27 pM (NADPH). Concentrations of NADPH greater than 150 pM caused substrate inhibition at low HMG-CoA concentrations resulting in deviations from linearity in secondary plots. Analysis of these data and the product inhibition pattern suggest a sequential mechanism for the reduction of HMG-CoA to mevalonic acid with HMG-CoA being the first substrate binding to the enzyme, followed by NADPH. 3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR)regulates the synthesis of mevalonic acid, the specific precursor of the myriad of isopentenoid compounds functional in plant biochemical processes. In mammalian cells this enzyme is generally regarded to be the most important ratecontrolling enzyme for cholesterogenesis. Because of the close relation between increased serum cholesterol levels and atherosclerosis in man and the possible involvement of HMGR in the regulation of the cell cycle, this enzyme has generated a great deal of interest [I -61. Comparably little information is available on the properties and regulation of plant HMGR. In recent work [7-91 it has been shown that, in radish seedlings, HMGR activity is Correspondence to T.