In the United States anthropogenic activities are mainly responsible for the wide spread perchlorate contamination of drinking water, surface water, groundwater, and soil. Even at microgram levels, perchlorate causes toxicity to flora and fauna and affects growth, metabolism and reproduction in humans and animals. Reports of antithyroid effects of perchlorate and its detection in common food items have raised serious public health concerns, leading to extensive decontamination efforts in recent years. Several physico-chemical removal and biological decontamination processes are being developed. Although promising, ion exchange is a non-selective and incomplete process as it merely transfers perchlorate from water to the resin. The perchlorate-laden spent resins (perchlorate 200-500 mg L(-1)) require regeneration resulting in production of concentrated brine (6-12% NaCl) or caustic waste streams. On the contrary, biological reduction completely degrades perchlorate into O(2) and innocuous Cl(-). High reduction potential of ClO(4)(-)/Cl(-) (E° =∼ 1.28 V) and ClO(3)(-)/Cl(-) pairs (E° =1.03 V) makes these contaminants thermodynamically ideal e(-) acceptors for microbial reduction. In recent years unique dissimilatory perchlorate reducing bacteria have been isolated and detailed studies pertaining to their microbiological, biochemical, genetics and phylogenetic aspects have been undertaken which is the subject of this review article while the various physico-chemical removal and biological reduction processes have been reviewed by others.

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In spite of ongoing annual vaccination programs, the seasonal influenza epidemics remain a major cause of high morbidity and mortality. The currently used "inactivated" vaccines provide very short-term and highly specific humoral immunity due to the frequent antigenic variations in the influenza virion. These intra-muscularly administered vaccines also fail to induce protective mucosal immunity at the portal of viral entry and destruction of the virally infected cells by induction of cytotoxic T lymphocytes. Therefore, it is necessary to develop immunologically superior vaccines. This article highlights some of the recent developments in investigational influenza vaccines. The most notable recent developments of interest include the use of immunopotentiators, development of DNA vaccines, use of reverse genetics, and the feasibility of mammalian cell-based production processes. Presently, due to their safety and efficacy, the cold-adapted "live attenuated" vaccines are seen as viable alternatives to the "inactivated vaccines". The DNA vaccines are gaining importance due to the induction of broad-spectrum immunity. In addition, recent advances in recombinant technologies have shown the possibility of constructing pre-made libraries of vaccine strains, so that adequately preparations can be made for epidemics and pandemics.

Bimolecular fluorescence complementation (BiFC) is based on the complementation between two nonfluorescent fragments of the yellow fluorescent protein (YFP) when they are united by interactions between proteins covalently linked to them. We have successfully applied BiFC in Neurospora crassa using two genes involved in meiotic silencing by unpaired DNA (MSUD) and observed macromolecular complex formation involving only SAD-1 proteins, only SAD-2 proteins, and mixtures of SAD-1 and SAD-2 proteins.

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