Herbicides that bind specifically to Photosystem II greatly increased ammonia liberation by a heterotrophic cyanobacterium incubated with methionine sulfoximine anaerobically in light. Comparison of cells incubated under argon and nitrogen indicated that about one-half of the liberated ammonia came from endogenous sources, as well as from dinitrogen fixation. Chromatography of cell extracts rev...

Rhodobacter sphaeroides only showed chemotaxis towards ammonia if grown under nitrogen-limited conditions. This chemotactic response was completely inhibited by the addition of methionine sulfoximine. There was no effect of methionine sulfoximine treatment on motility or taxis towards propionate, demonstrating that the effect is specific to ammonia taxis. It is known that methionine sulfoximine...

The reduction of ammonia-nitrogen fluxes from polluted streams entering the Tai Lake is an important task in areas with limnetic eutrophication. Biofilm technique for the polluted streams has been proposed as one effective method to reduce ammonia-nitrogen fluxes entering the Tai Lake. In this study, ammonia-nitrogen biodegradation in a created biofilm purification engineering was evaluated by ...

Fishes, in general, follow ammonotelic mode of excretion. However, certain stress factors may provoke them to excrete urea. In the present study, the possible role of ureogenesis to avoid accumulation of toxic ammonia under water-restricted condition was tested in Heteropneustes fossilis. A total of hundred fishes were collected and sacrificed. Excretory urea and ammonia were estimated in the w...

We introduce the notion of hyper-self-duality for Bose-Mesner algebras as a strengthening of formal self-duality. LetM denote a Bose-Mesner algebra on a finite nonempty set X . Fix p ∈ X , and letM∗ and T denote respectively the dual Bose-Mesner algebra and the Terwilliger algebra ofMwith respect to p. By a hyper-duality ofM, we mean an automorphism ψ of T such that ψ(M) =M∗, ψ(M∗) =M; ψ2(A) = ...

Nonresonant hyper-Raman and hyper-Rayleigh spectra excited at 1064 nm are reported for neat benzene and pyridine. The theory of Herzberg-Teller vibronic coupling in nonresonant and preresonant hyper-Raman scattering is developed. Nonresonant hyper-Raman scattering is shown to be vibronically induced by modes that efficiently couple strongly allowed onephoton and two-photon transitions. A weak a...

In 2004,ammonia concentration in raw water of Sitalakhya River at the eastern periphery of Dhaka was found higher than the expected rate of 4 mg/Lforecasted in feasibility studies,with a value of about 8 mg/L, which could not be removed by conventional treatment chain employed at Dhaka, hence, recentlyan ammonia removal plant has been constructed. This important background has ledto the current...

The objective of this experiment was to determine the capability of ruminant gut tissues to detoxify ammonia-N using short-term incubations of isolated cells in vitro. Ruminal epithelial cells (REC) and duodenal mucosal cells (DMC) were isolated from growing Texel-Polypay ram lambs (n = 4) fed a pelleted forage:concentrate-based diet. Immediately after isolation, primary cells were incubated fo...

Remarkably little is known about nitrogenous excretion in freshwater invertebrates. In the current study, the nitrogen excretion mechanism in the carnivorous ribbon leech, Nephelopsis obscura, was investigated. Excretion experiments showed that the ribbon leech is ammonotelic, excreting 166.0 ± 8.6 nmol·grams fresh weight (gFW)(-1)·h(-1) ammonia and 14.7 ± 1.9 nmol·gFW(-1)·h(-1) urea. Exposure ...