Ein neues Verfahren zur Messung der radialen Temperaturverteilung in inhomogenen und instationären Plasmasäulen mit erheblicher Selbstabsorption

The complete lateral distributions of emitted intensity and optical thickness of the instationary plasma column are measured simultaneously by probing the plasma with its own radiation and recording both distributions on a single high-speed spectrum. From these lateral distributions the radial distributions of the coefficients of emission and absorption are calculated and by application of Kirchhoff’s law the radial temperature distribution is determined. This new technique has been applied to an exploding wire plasma with 37 000 K on the axis. The mean deviations of three temperature distributions obtained by independent measurements at different wavelengths are less than 3 per cent

Selective Predation on the Seeds of Woody Plants

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the higher ground-layer heterogeneity of the old field site. We conclude that predator choice will allow some species to escape seed predation, potentially altering future plant community composition

Selective Predation on the Seeds of Woody Plants

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the higher ground-layer heterogeneity of the old field site. We conclude that predator choice will allow some species to escape seed predation, potentially altering future plant community composition

Integration of knowledge in river restoration

River engineeringRiver habitat management and restoratio

Development of a chromium-thoria alloy

Low temperature ductility and high temperature strength of pure chromium and chromium-thoria alloy prepared from vapor deposited powder

Fungal Spore Dispersal by the Eastern Box Turtle (Terrapene carolina carolina)

Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate spores, quantify the number of spores per gram of fecal material and to isolate and identify fungi. Fungal spores were found to be extremely abundant throughout all samples. Fecal samples from 36 turtles yielded a total of 23 different fungal taxa in the Zygomycota, Ascomycota and Basidiomycota. Two yeasts that were isolated, Cryptococcus albidus and Rhodotorula mucilaginosa, are reported to naturally occur on Trifolium seeds found in fecal samples. A mold previously unreported from fecal material, Aspergillus wentii, was also found in fecal samples. Data collected suggests Eastern box turtles influence fungal spore dispersal by browsing on plant materials and defecating large numbers of fungal spores within their home ranges

The UvrD303 Hyper-helicase Exhibits Increased Processivity

DNA helicases use energy derived from nucleoside 5′-triphosphate hydrolysis to catalyze the separation of double-stranded DNA into single-stranded intermediates for replication, recombination, and repair. Escherichia coli helicase II (UvrD) functions in methyl-directed mismatch repair, nucleotide excision repair, and homologous recombination. A previously discovered 2-amino acid substitution of residues 403 and 404 (both Asp → Ala) in the 2B subdomain of UvrD (uvrD303) confers an antimutator and UV-sensitive phenotype on cells expressing this allele. The purified protein exhibits a “hyper-helicase” unwinding activity in vitro. Using rapid quench, pre-steady state kinetic experiments we show the increased helicase activity of UvrD303 is due to an increase in the processivity of the unwinding reaction. We suggest that this mutation in the 2B subdomain results in a weakened interaction with the 1B subdomain, allowing the helicase to adopt a more open conformation. This is consistent with the idea that the 2B subdomain may have an autoregulatory role. The UvrD303 mutation may enable the helicase to unwind DNA via a “strand displacement” mechanism, which is similar to the mechanism used to processively translocate along single-stranded DNA, and the increased unwinding processivity may contribute directly to the antimutator phenotype

Разработка электроэнцефалографа на наносенсорах для исследования мозга человека в расширенном диапазоне частот

В выпускной квалификационной работе проведен анализ методов исследования мозга человека. Выбрана электроэнцефалография в качестве основного метода регистрации биоэлектрической активности с помощью наносенсоров. Разработан электроэнцефалограф для исследования мозга человека в расширенном диапазоне частот (0-10000 Гц), позволяющий получить дополнительную информацию о регистрируемых биопотенциалах и ритмах ЭЭГ. Проведено исследование для оценки психоэмоционального состояния человека и исследование для подтверждения возможности использования разработанного электроэнцефалографа в качестве электронейромиографа.IIn the final qualifying work, an analysis of methods of studying the human brain was carried out. Electroencephalography was chosen as the main method for recording bioelectrical activity with nanosensors. The developer is an electroencephalograph for studying the human brain in the extended frequency range (0-10000 Hz), which allows obtaining additional information on the detected bioelectric potentials and EEG rhythms. A study was conducted to assess the psychoemotional state of a person and study to confirm the possibility of using the developed electroencephalograph as an electroneuromiograph