The properties of the postsynaptic muscarinic receptors of a ventral giant interneurone in the sixth abdominal ganglion of the cockroach were studied using the single-fibre oilgap technique. 1. Pressure-ejections of 1024 mol l21 arecoline (ARE) and muscarine evoked a small (approximately 1mV), prolonged slow depolarization whereas the muscarinic agonist McN-A-343 (1023 mol l21) elicited only a ...

Sedimentary biogenic silica (BSi) accumulation was used in conjunction with a hypothetical model of BSi accumulation to show that BSi is a sensitive proxy for low-level phosphorus enrichment in the Great Lakes. We hypothesize that historic nutrient-driven changes in diatom production altered silica biogeochemistry and induced biologically mediated silica depletion (BMSD) and that a record of th...

A flow injection manifold is proposed for the sequential determination of titratable (total) acidity based on a pseudotitration and of tartaric acid based on the formation of a coloured vanadate complex. The method involves in-line dialysis prior to injection to avoid interference from the sample background absorption in the spectrophotometric detection. The changes in the colour of both reacti...

Architecture of higher plant chloroplast ribosomes involves additional protein domains over that found in the Escherichia coli ribosome, although the rRNAs in these two kinds of ribosomes are very similar in length and sequence (Subramanian, A. R. (1993) Trends Biochem. Sci. 18, 177-180). Here, we show that two chloroplast-specific protein domains (a novel chloroplast ribosomal protein of the 3...

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L21, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L21) and increased with depth. The photoproduction rate of OC...

Heat treatments of single crystals Ni44Fe19Ga27Co10 (at.%) shape memory alloys cause various microstructures the high-temperature phase. The nanodomain structure, consisting regions L21- and B2-phases, nanosized particles are main parameters that change during heat determine mechanism nucleation growth martensite crystals, size thermal-induced lamellae, temperature Ms, intervals martensitic tra...

The Laser Engineered Net Shaping (LENS) technique was combined with direct synthesis to fabricate L21-ordered Fe-Al-Ti based intermetallic alloys. It was found that ternary Fe-Al-Ti alloys can be synthesized using the LENS technique from a feedstock composed of a pre-alloyed Fe-Al powder and elemental Ti powder. The obtained average compositions of the ternary alloys after the laser deposition ...

Although an enhanced magnetoresistance (MR) has been observed in many Co2-based Heusler alloys by promoting their structural ordering from B2 to L21 post-annealing at higher temperatures (Tann > 500 °C), it is desirable search for other that crystallize L21-order below 300 °C, as the maximum Tann restricted processing devices. For Co2MnZ (Z = Ge, Sn) alloys, expected appear even as-depos...

The performance and optimization of an anion exchanger phase (SAX) in line with a hydrophobic phase (C18) was studied for the preconcentration of selenite [Se(iv)], selenate [Se(vi)], dimethylselenide (DMSe), dimethyldiselenide (DMDSe), diethylselenide (DESe) and diethyldiselenide (DEDSe), using a GC-MS system to characterize the different selenium species. Optimum separation and preconcentrati...

The pentapeptide proctolin has multiple effects on the locust oviposition digging system. At the neuromuscular junction of the ventral opener muscle, it has a concentration-dependent range of modulatory effects. At low concentrations (10210 mol l21), proctolin causes an increase in the frequency of miniature excitatory junctional potentials, but has no apparent effects on the muscle membrane or...