Ultrastructural Analysis of Drosophila Ovaries by Electron Microscopy

The Drosophila melanogaster ovary is a powerful, genetically tractable system through which one can elucidate the principles underlying cellular function and organogenesis in vivo. In order to understand the intricate process of oogenesis at the subcellular level, microscopic analysis with the highest possible resolution is required. In this chapter, we describe the preparation of ovaries for ultrastructural analysis using transmission electron microscopy and focused ion beam scanning electron microscopy. We discuss and provide protocols for chemical fixation of Drosophila ovaries that facilitate optimal imaging with particular attention paid to preserving and resolving mitochondrial membrane morphology and structure

Bacteriocinogenic potential and genotypic characterization of three Enterococcus faecium isolates from Algerian raw milk and traditional butter

The detection of bacteriocinogenic potential of Enterococcus sp. isolates from Algerian raw milk coded LO4 and LO12 and from traditional butter coded BRO2 was carried on M17 buffered medium. PCR amplification of Enterococcus sp. DNA using specific enterococcal primers gave 733 bp fragments. The phylogenetic analysis using the neighbour joining method further supported the identification of the three strains as Enterococcus faecium. These bacteria were bacteriocinogenic against Pseudomonas sp, Proteus mirabilis and E. faecium. Lyophilisate extracts were tested for sensitivity to enzymes, heating and effect of pH. Complete inactivation in bacteriocinogenic activity was observed after treatment with proteolytic enzymes. The antibacterial activity from E faecium LO12 was stable (1280 AU/ml) for range pH 2 to 12. Maximal activity from BRO2 strain was at pH 7 (20480 AU/ml) and from LO4 strain was at pH 7 and 6 (2560 AU/ml). Antibacterial activities of E. faecium BRO2 (5120 AU/ml) and E. faecium LO12 (640 AU/ml) remained stable at 60°C for 30 min. The antibacterial activity of .E faecium LO4 was stable at 100°C for 30 min (5120 AU/ml)

The physics of wind-blown sand and dust

The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This article presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.Comment: 72 journal pagers, 49 figure

Calcitonin control of calcium metabolism during weightlessness

The main objective of this proposal is to elucidate calcitonin role in calcium homeostasis during weightlessness. In this investigation our objectives are to study: the effect of weightlessness on thyroid and serum calcitonin, the effect of weightlessness on the circadian variation of calcitonin in serum and the thyroid gland, the role of light as zeitgeber for calcitonin circadian rhythm, the circadian pattern of thyroid sensitivity to release calcitonin in response to calcium load, and the role of serotonin and norepinephrine in the control of calcitonin release. The main objective of this research/proposal is to establish the role of calcitonin in calcium metabolism during weightlessness condition. Understanding the mechanism of these abnormalities will help in developing therapeutic means to counter calcium imbalance in spaceflights