background: iron, manganese, and aluminum are three abundant metals on earth and their concentrations have increased in aquatic environments as a result of natural and industrial activities. this study was undertaken to report the median acute toxicity (lc50) and accumulation of the sub-lethal concentration (10% 96-h lc50) of iron (fe), manganese (mn) and aluminum (al) in kutum (rutilus kutum) ...

spirulina platensis, a cyanobacterium of economic important was studied for the tolerance to cadmium. the bioassay studies showed the ec50 value to be 1.53 mg/g. the cyanobacterium was very sensitive to low metal concentration and the productivity was also reduced. the chlorophyll pigments reduced with decreasing the algal biomass. the algal survival rate showed a marked reduction in their surv...

Earthworms represent an important food source for many vertebrates and as a result, predators may encounter toxic effects via the food chain from consumption of contaminated worms. Therefore, including an assessment of xenobiotic to worms in risk assessment procedures is advisable. Here we studied the acute toxicity, bioaccumulation and elimination of ethofumesate enantiomers in earthworm, Eise...

We provide a holographic description of the BMN matrix model and its 1/2 BPS vacua, e.g. the concentric fuzzy spheres, by dual IIA supergravity solutions. We apply the Polchinski-Strassler method to construct our solutions, due to the similarity of the vacuum structure of this model and the N = 1∗ theory. The dual solutions have brane configurations which are concentric shells of S-wrapped D2 b...

We study the internal dynamics of Ramond-Ramond solitons excited far from the BPS limit by leading Regge trajectory open strings. The simplest world volume process for such strings is splitting into two smaller pieces, and we calculate the corresponding decay rates. Compared to the conventional open superstring, the splitting of states polarized parallel to the brane is suppressed by powers of ...

We study the superstring theory on pp-wave background with NSNS-flux that is realized as the Penrose limit of AdS3 × S3 × M4, where M4 is T 4 or T 4/Z2(∼= K3). Quantizing this system in the covariant gauge, we explicitly construct the space-time supersymmetry algebra and the complete set of DDF operators. We analyse the spectrum of physical states by using the spectrally flowed representations ...

We study the vacuum polarization of a massless minimally coupled scalar field at the horizon of four-charge STU black holes. We compare the results for the standard asymptotically flat black holes and for the black holes obtained in the “subtracted limit”, both in the general static case and at the horizon pole for the general rotating case. The original and the subtracted results are identical...

Epsilon toxin (Etx) from Clostridium perfringens is a pore-forming protein with a lethal effect on livestock, producing severe enterotoxemia characterized by general edema and neurological alterations. Site-specific mutations of the toxin are valuable tools to study the cellular and molecular mechanism of the toxin activity. In particular, mutants with paired cysteine substitutions that affect ...