Deficiency of toxin-binding protein activity in mutants of sugarcane clone H54-775 as it relates to disease resistance

Three mutants selected from a population of sugarcane clone H54-775 that had been irradiated with 3 kR gamma-radiation all lacked toxin-binding protein activity. This activity previously had been shown to be essential for eye spot disease susceptibility and was demonstrated in the susceptible parent clone H54-775. In one mutant, the biochemical, immunochemical, and electrophoretic mobilities of the toxin-binding protein were all modified.     

Note: NAMD–LP: Filtering and Translating NAMD-generated Files

Abstract

We have empirically tested limits of the magnitude of multiple time steps in molecular dynamics simulations of aqueous systems, and the extent to which these offer a means to shorten computation time. Three different steps were employed, δ₀t for calculation of “bonded” forces, δ₁t for calculations of short-range (< 6 Å) non-bonded forces, and δ₂t for long-range (< 10 Å) non-bonded forces. Each longer step was a multiple of the shortest one. The leap-frog integration algorithm was used with SHAKE for restraint of all bond lengths and water molecules. For a system of SPC water molecules, calculation of short-range non-bonded forces could be done with a time step δ₁t = 10 fs, without appreciable change of the average temperature and energy, radial distribution function or diffusion coefficient. These properties were found to be insensitive to the inclusion of long-range non-bonded forces. A multiple-step protocol with δ₀t = 2, δ₁t = 4 and δ₂t = 16 fs has been compared with a single-step procedure with δt 2 fs for small polypeptides in water. The exploration of conformation space, with crossing of low energy barriers, was tested with the glycine dipeptide and was found to proceed at similar rates. Mean, hysteresis and statistical error of the free energy for changing alanine to α-amino butyric acid in the dipeptide, calculated by the slow-growth method, proved independent of the cutoff distance or exact protocol, within 1 kJ/mol. In conclusion, we recommend, instead of use of a single time step of 2 fs at a 10 Å cutoff, use of a time step δ_t = 4 fs for short-range nonbonded forces and a time step δ₂t = 16 fs for long-range nonbonded forces for a 60% reduction of computation time.     

The Paleobiosphere: a novel device for the in vivo testing of hydrocarbon producing-utilizing microorganisms

The construction and testing of a unique instrument, the Paleobiosphere, which mimics some of the conditions of the ancient earth, is described. The instrument provides an experimental testing system for determining if certain microbes, when provided an adequate environment, can degrade biological materials to produce fuel-like hydrocarbons in a relatively short time frame that become trapped by the shale. The conditions selected for testing included a particulate Montana shale (serving as the “Trap Shale”), plant materials (leaves and stems of three extant species whose origins are in the late Cretaceous), a water-circulating system, sterile air, and a specially designed Carbotrap through which all air was passed as exhaust and volatile were hydrocarbons trapped. The fungus for initial testing was Annulohypoxylon sp., isolated as an endophyte of Citrus aurantifolia. It produces, in solid and liquid media, a series of hydrocarbon-like molecules. Some of these including 1,8-cineole, 2-butanone, propanoic acid, 2-methyl-, methyl ester, benzene (1-methylethyl)-, phenylethyl alcohol, benzophenone and azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl), [1S-(1α,7α,8aβ)]. These were the key signature compounds used in an initial Paleobiosphere test. After 3 weeks, incubation, the volatiles associated with the harvested “Trap Shale” included each of the signature substances as well as other fungal-associated products: some indanes, benzene derivatives, some cyclohexanes, 3-octanone, naphthalenes and others. The fungus thus produced a series of “Trap Shale” products that were representative of each of the major classes of hydrocarbons in diesel fuel (Mycodiesel). Initial tests with the Paleobiosphere offer some evidence for a possible origin of hydrocarbons trapped in bentonite shale. Thus, with modifications, numerous other tests can also be designed for utilization in the Paleobiosphere.     

Stereoselective Synthesis of 1- and 2-O-α-d-Cellotriosyl-3-deoxy-2(R)- and 2(S)-glycerols Related to Rhynchosporoside

The stereoselective synthesis of 1- and 2-O-α-d-cellotriosyl-3-deoxy-2(R)- and 2(S)-glycerols, which determined the structure of rhynchosporoside produced by Rhynchosporium secalis, and their phytotoxicity toward the host plant (Hordeum vulgare) are described in detail.     

Does family language matter? The role of foreign language use and family social capital in the educational achievement of immigrant students in Germany

The role of ethnic resources in the educational success of immigrants is highly disputed. Combining arguments of segmented assimilation and Coleman's concept of family social capital, this study investigates whether speaking one's language of origin at home relates to achievement by facilitating the mobilization of resources or their transmission from parents to children. Mediating and moderating mechanisms are disentangled and empirically questioned in regression models that predict the mathematical competences of immigrant students from Turkey, Poland and the former Soviet Union. Based on data from the German National Educational Panel Study, the results contradict the assumption that foreign language use will contribute to education through mechanisms of social capital. Regardless of parental human capital or the group of origin, the language used at home does not affect the students’ learning when German language proficiency is accounted for.     

Novel,X-ray supported kinetic imaging of hidden-lifestyle arthropods

Dear Editor,There are several arthropods,which live and develop covertly in plant tissues.The plant tissues surrounding them provide them with shelter during their vulnerable developing stage or ensure overwintering as well as they can supply them with essential food for their ontogenetic development(McNaughton,1983).