During many clear twilights, much of the solar sky is dominated by pastel purples. This purple light's red component has long been ascribed to transmission through and scattering by stratospheric dust and other aerosols. Clearly the vivid purples of post-volcanic twilights are related to increased stratospheric aerosol loading. Yet our time-series measurements of purple-light spectra, combined ...

Carbon dixoide is reduced anaerobically to cell substance and water by the hydrogen donor H%A through the agency of photosynthetic pigments with the absorption of radiant energy. Two more or less clear-cut groups ca be distinguished among the purple bacteria on the basis of their physiological characteristics. One group, the sulfur purple bacteria (family Thiorhodeae Molihch, 1907) can develop ...

Wheat (Triticum aestivum L.) cultivars possessing purple grain arethought to be more nutritious because of high anthocyanin contents in the pericarp. Comparative transcriptome analysis of purple (cv Gy115) and white pericarps was carried out using next-generation sequencing technology. There were 23,642 unigenes significantly differentially expressed in the purple and white pericarps, including...

Mammalian and plant purple acid phosphatases have similar active site structures despite low sequence identity (<20%). Although no bacterial enzyme has been purified, a sequence database search revealed that genes that could encode potential purple acid phosphatases may be restricted to a small number of organisms (i.e. myco- and cyanobacteria). Analysis of their deduced amino acid sequences an...

We located a heavy metal label, mercurilated phenylglyoxal, in both the primary sequence and in the tertiary structure of bacteriorhodopsin. This label modified arginines 225 and 227, which are on the COOH-terminal helix (G). In the projected electron potential difference map, the major site is close to the central inner helix. From this result we conclude that helix 1 could not be the COOH-ter...

The purple membrane is a two-dimensional crystalline lattice formed by bacteriorhodopsin and lipid molecules in the cytoplasmic membrane of Halobacterium salinarum. High-resolution structural studies, in conjunction with detailed knowledge of the lipid composition, make the purple membrane one of the best models for elucidating the forces that are responsible for the assembly and stability of i...

Aerial predator-prey interactions may impact populations of many terrestrial species. Here, we use altitude loggers to study aerial foraging in a native insectivore, the purple martin (Progne subis), in the southern USA. Purple martins fed primarily on mating queens and males of the invasive red imported fire ant (Solenopsis invicta), and doubled their foraging efficiency by doing so. Across th...

The genotypic variation on physico-chemical characteristics of wild grown plums (Prunus spinosa L.) was investigated. The total phenolic contents were in a range of 117 to 407 mg GAE/100 g FW. The vitamin C was highest in yellow colored fruits (12.10 mg/100 ml). The total soluble solid content varied between 9.40% (yellow colored) and 12.90% (dark purple colored) fruits.  Antioxidant activity o...

Purple corn (Zea mays L.), a grain with one of the deepest shades in the plant kingdom, has caught the attention of the food industry as it could serve as a source for alternatives to synthetic colorants. Also being rich in phenolic compounds with potential health-promoting properties, purple corn is becoming a rising star in the novel ingredients market. Although having been widely advertised ...

1. Measurements of visual purple regeneration in solution have been made by a procedure which minimized distortion of the results by other color changes so that density changes caused by the regenerating substance alone are obtained. 2. Bleaching a visual purple solution with blue and violet light causes a greater subsequent regeneration than does an equivalent bleaching with light which lacks ...