Low temperature reduction of hexavalent chromium by a microbial enrichment consortium and a novel strain of Arthrobacter aurescens

Background  

Chromium is a transition metal most commonly found in the environment in its trivalent [Cr(III)] and hexavalent [Cr(VI)] forms. The EPA maximum total chromium contaminant level for drinking water is 0.1 mg/l (0.1 ppm). Many water sources, especially underground sources, are at low temperatures (less than or equal to 15 Centigrade) year round. It is important to evaluate the possibility of microbial remediation of Cr(VI) contamination using microorganisms adapted to these low temperatures (psychrophiles).     

Food choices and habitat use by the Tana River yellow baboons (Papio cynocephalus): a preliminary report on five years of data

The Tana River Primate National Reserve, Kenya (TRPNR) yellow baboons' (Papio cynocephalus) long‐term habitat usage and food preferences are relatively under‐reported. The author presents a preliminary food catalog and analyses of 5 years of data (January 88–October 92; n=55 mo; 875 observation days; 4,893 hourly scans) for the Mchelelo troop (x̄=75 individuals). The author predicted that the TRPNR baboons would spend more time on the much larger savanna, show a seasonal preference for fruits/seeds, and show rainfall‐influenced food preferences. Although more time was spent on the proportionately larger savanna than in the forests, more than 42% of the observations occurred in forests that accounted for only 8.7% of the area regularly used by the baboons. Fruits/seeds consumption was high throughout the period and a significantly higher proportion of each month's observations reflected fruits/seeds rather than grasses/herbs/corms consumption. Two forest species' (Phoenix reclinata and Hyphaene compressa) were particularly important. Regression analysis showed fruits/seeds consumption predicted most of the grasses/herbs/corms consumption variance. There was no statistical difference in rainy vs. non‐rainy season fruits/seeds or grasses/herbs/corms consumption. One implication of these data is the baboons' potential impact on the critically endangered Tana River mangabeys (Cercocebus galeritus), which also rely heavily on P. reclinata and H. compressa. Another is what the “savanna” designation may or may not tell us about baboons. Am. J. Primatol. 71:432–436, 2009. © 2009 Wiley‐Liss, Inc.     

Implications for the Maintenance of Androdioecy in the Freshwater Shrimp, Eulimnadia texana Packard: Encounters between Males and Hermaphrodites are not Random

Androdioecy is a mixed‐mating system in which there are males and hermaphrodites but no pure females. Few species exhibit such a mating system. Eulimnadia texana is a branchiopod crustacean that has recently been identified as an androdioecious species. This system is ideal for testing questions related to the evolution of sexual reproduction. We are testing a model that predicts androdioecy to be a stable mixed‐mating system under certain conditions. Specifically, we investigated whether encounters between males and hermaphrodites are random or if either sex seeks out the other for mating. Focal male or hermaphrodite clam shrimp were presented with stimulus shrimp of the other sex or kept alone. Swimming speed and time spent within different areas of a test chamber were recorded. Males did not alter mean swimming speed or spend more time than expected by chance near partitioned hermaphrodites. Hermaphrodites, however, decreased mean swimming speed in the presence of males and also spent more time than expected by chance near partitioned males, suggesting that hermaphrodites respond to male chemical and/or visual stimuli. Modified swimming behaviour probably facilitates inter‐sexual contact, thereby increasing opportunities for out‐crossing above that expected by random encounters.     

Phospholipase D,tumor promoters,proliferation and prostaglandins

Phosphatidylcholine hydrolysis by phospholipase D is a widespread response to cellular stimulation. However, the downstream signaling events subsequent to phosphatidylcholine hydrolysis are just beginning to be determined. Initially it was proposed that diglyceride formation by phospholipase D and phosphatidate phosphohydrolase resulted in long-term stimulation of protein kinase C. However, recent studies indicate that phosphatidic acid is the relevant signaling molecule in some signaling pathways. The present review will summarize studies of phospholipase D in the response of cells to the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate, which causes cells to mimic the phenotype of oncogenic transformation. The role of phospholipase D in stimulation of Raf-1 and prostaglandin H synthase type-2 is emphasized.     

An intracellular conformational sensor assay for Abl T315I

Conformational change is a common molecular mechanism for the regulation of kinase activities. Small molecule modulators of protein conformations, including allosteric kinase inhibitors, are highly wanted as tools for the interrogation of kinase biology and as selective therapeutic agents. However, straightforward cellular assays monitoring kinase conformations in a manner conducive to high-throughput screening (HTS) are not readily available. Here we describe such an HTS-compatible conformational sensor assay for Abl based on a split luciferase construct. The Abl sensor responds to intramolecular structural rearrangements associated with intracellular Abl deactivation and small molecule inhibition. The intact regulatory CAP-SH3-SH2 domain is required for the full functionality of the sensor. Moreover, a T334I Abl mutant (T315I in Abl1a) was found to be particularly well suited for HTS purposes and mechanistic intracellular studies of T334I mutant inhibitors. We expect that the split luciferase-based conformational sensor approach might be more broadly useful to probe the intracellular activation of other kinases and enzymes in general.     

Social play behaviours and insect predation in northern grasshopper mice (Onychomys leucogaster)

Play behaviours of northern grasshopper mice, $\text{Onychomys leucogaster}$, were observed from 27 to 61 days of age and after a brief period of social isolation. The mice were also observed during a simple test of cricket predation. With the exception of an active play-soliciting response, the play behaviours were quite similar to those described for other rodents. Play declined with increasing age and was strongly potentiated by social isolation. There was no discernable relationship between any of the play measures and efficiency of cricket predation. There were no detectable sex differences in either play or predation.     

Visualization of proteases within a complex sample following their selective retention on immobilized bacitracin, a peptide antibiotic.

A method for the visualization of individual proteases within a complex biological sample is described. In a single chromatographic step, proteases can be separated from other biomolecules by selective binding to immobilized bacitracin, a peptide antibiotic. Following desorption, proteases may be separated by SDS-polyacrylamide gel electrophoresis. The application of this method is presented in the visualization of proteases secreted by the fungus Aspergillus niger.     

A fine structural study of metamorphosis of the hydrozoan Mitrocomella polydiademata

This report is a comprehensive fine structural analysis of the morphological changes occurring during metamorphosis of the marine hydrozoan Mitrocomella polydiademata. Five stages are recognized during metamorphosis: planulae just prior to settlement, ball and filiform stages, immature polyps, and primary feeding polyps. Settlement and metamorphosis of cnidarian planulae involve such changes as ciliary arrest, discharge of nematocytes, secretion of glandular cells, differentiation of cells, and changes in cell and body shape.     

Carotenoids of Prymnesiophyceae (Haptophyceae)

A quantitative study, including mass spectrometric identification, of the carotenoids isolated from some selected prymnesiophytes harvested in exponential growth phase has been carried out. Isochrysis galbana, Hymenomonas carterae, Prymnesium parvum, Pavlova (Monochrysis) lutheri and a Pavlova sp. all produce β,β-carotene, diatoxanthin, diadinoxanthin and fucoxanthin (major carotenoid) in various proportions, in addition to several minor carotenoids were found characteristic of each alga. 19'-Hexanoyloxyfucoxanthin, previously shown to be the major carotenoid in the prymnesiophyte Emeliana (Coccolithus) huxleyi, was not encountered in the Prymnesiophyceae studied here, and we conclude that this carotenoid should be critically looked for in other members of the Gephyrocapsaceae to which E. huxleyi belongs. We further conclude that the carotenoid complement of the Chrysophyceae (in the narrow sense) should be compared with that of the Prymnesiophyceae.