AIMS To detect enteric microsporidia in faecal specimens from patients with the acquired immunodeficiency syndrome (AIDS), and to identify the spores to species level without using invasive procedures. METHODS Formalised faecal preparations were examined using a modification of the strong trichrome staining method to demonstrate microsporidian spores. Six positive specimens were prepared for ...

Dormant spores of a Bacillus subtilis mutant that lacks two major small, acid-soluble spore proteins are very sensitive to UV irradiation, which in spores generates about half the amount of thymine-containing dimers formed by comparable irradiation of vegetative cells. Irradiation of mutant spores also produces spore photoproducts, but again only about one-half the amount formed in comparably i...

Clostridial spore germination requires degradation of the spore's peptidoglycan (PG) cortex by cortex-lytic enzymes (CLEs), and two Clostridium perfringens CLEs, SleC and SleM, degrade cortex PG in vitro. We now find that only SleC is essential for cortex hydrolysis and viability of C. perfringens spores. C. perfringens sleC spores did not germinate completely with nutrients, KCl, or a 1:1 chel...

Previous studies have described both surface morphology and adhesive properties of fungal spores, but little information is currently available on their mechanical properties. In this study, atomic force microscopy (AFM) was used to investigate both surface topography and micromechanical properties of Aspergillus nidulans spores. To assess the influence of proteins covering the spore surface, w...

A spore assay was developed to measure the relative density of spores of the nematophagous fungus Hirsutella rhossiliensis in soil. Orchard soil containing H. rhossiliensis-parasitized Criconemella xenoplax was placed in vials and incubated for 0-120 days before the addition of probe nematodes, Heterorhabditis heliothidis juveniles. After 18 hours, H. heliothidis were extracted from the soil an...

In situ neutron powder diffraction measurements show that the orthorhombic-to-tetragonal phase transition in YBa2Cu307 —,which occurs near 700 C in a pure oxygen atmosphere, is an order-disorder transition in which the disordering of oxygen atoms into a normally vacant site destroys the one-dimensional Cu-0 chains present in the room-temperature orthorhombic structure. For both structures, the ...

Electromechanical property measurements and microstructure observations using optical microscopy were performed on a [001] c oriented k33 resonator made of 91%Pb(Zn1/3Nb2/3)O3-9%PbTiO3 single crystal, which was polarized under different electric fields. At room temperature, when the poling field is 1100 V/mm, the electromechanical coupling factor k33 is 0.90 and piezoelectric coefficient d33 is...

Cytochrome c(2) serves as the secondary electron donor that reduces the photo-oxidized bacteriochlorophyll dimer in photosynthetic bacteria. Cytochrome c(2) from Rhodobacter sphaeroides has been crystallized in three different forms. At high ionic strength, crystals of a hexagonal space group (P6(1)22) were obtained, while at low ionic strength, triclinic (P1) and tetragonal (P4(1)2(1)2) crysta...

The high-pressure polymorphs of CuI have attracted much attention due to the somewhat contradictory identification of their structures by means of x-ray diffraction measurements and theoretical calculations. In this paper, we report the results of a theoretical investigation of polymorphs of CuI including zinc-blende, rhombohedral, tetragonal, rocksalt and orthorhombic phases. We find that CuI...

High-temperature phases of hafnium dioxide have exceptionally high dielectric constants and large bandgaps, but quenching them to room temperature remains a challenge. Scaling the bulk form to nanocrystals, while successful in stabilizing the tetragonal phase of isomorphous ZrO2, has produced nanorods with a twinned version of the room temperature monoclinic phase in HfO2. Here we use in situ h...