First record of gregarine protists (Apicomplexa: Sporozoa) in Asian fungus-growing termite Macrotermes barneyi (Blattaria: Termitidae)

Macrotermes barneyi, widely distributed in southern China, is the major fungus-growing termite in the subfamily Macrotermitinae. It has no flagellated protists in the guts. Here, we report occurrence of gregarine, a protozoan parasite in the digestive tract of M. barneyi. The general morphology and ultrastructure of the gregarine gamonts and syzygies by light micrograph and scanning electron micrograph are presented. SSU rDNA sequence analysis showed that the termite gregarine has the highest identity (90.10%) to that of Gregarina blattarum from cockroaches. Phylogenetic analysis based on the SSU rDNA sequences from diverse insect eugregarines indicated that the gregarine from M. barneyi is phylogenetically close to G. blattarus, L. erratica and G. tropica from Gregarinidae and Leidyanidae families, and may represent a novel species. This study expands our knowledge about the diversity of terrestrial eugregarines parasitizing in termites.

Physicochemical and emulsifying properties of pre-treated octenyl succinic anhydride (OSA) sago starch in simple emulsion system

A study was carried out to determine the physicochemical and emulsifying properties of pre-treated octenyl succinic anhydride (OSA) sago starch in simple emulsion. Sago starch was pre-treated with STARGEN enzyme (EN OSA: single pre-treatment), heat moisture treatment followed by STARGEN enzyme (HMT EN OSA: dual pre-treatment) before being esterified with OSA. The ability of the pre-treated OSA sago starch to stabilize emulsion was then investigated. Dual pre-treated starch, HMT EN OSA, had significantly highest degree of substitution (DS), (DS = 0.0179) compared to single pre-treated starch, EN OSA, (DS = 0.0159) and native OSA, N-OSA (DS = 0.0057). As compared to emulsions prepared by N-OSA and HMT EN OSA, EN OSA had significantly highest emulsifying activity throughout all starch concentrations and it produced a thick viscous emulsion layer directly after emulsification. This might be due to enzymatic pretreatments may retained granule’s original shape and smooth appearance which allow having a better fit during the emulsification process. The highest emulsion stability was observed with the emulsion index values of EN OSA stabilized emulsions was the most stable for all starch concentrations throughout storage study. After the 8th week of storage study, the EN OSA remains the highest emulsion index from 0.37 to 0.56 for 200 mg/mL oil to 500 mg/mL oil starch concentration. Light micrograph of EN OSA showed that starch particles accumulated at the oil-water interface and cover the oil droplets with higher degree of coverage than the HMT EN OSA and control. No spaces were observed in the EN OSA stabilized emulsion which indicated that EN OSA modified sago starch can effectively stabilize oil in water emulsion.

Guidance for Choosing When to Use Electron and/or Light Microscopy and Related ASTM E4 Standards

Technical publications sometimes include scanning electron images to characterize a microstructure, when the relevant structure could have very easily been illustrated using a simple light micrograph. When should one use a light generated image? What are the advantages/disadvantages of an electron generated image, particularly; one generated using a scanning electron microscope (SEM)? While there is some overlap in the capabilities of these imaging systems; in general, they are complementary tools, each with their own uses. Standards under the jurisdiction of ASTM Committee E4 on Metallography offer guidance to both new and experienced users of both investigative techniques.

Parental Genome Separation in Reconstructions of Somatic and Premeiotic Metaphases of Hordeum Vulgare × H. Bulbosum

A stable interspecific sexual plant hybrid between Hordeum vulgare cv. Tuleen 346 (barley) × H. bulbosum was shown to have seven chromosomes originating from each parent by genomic in situ hybridization. Electron microscope serial thin-section reconstructions of metaphases and comparison with light micrograph karyo-types enabled chromosomes to be identified from their morphology. The three-dimensional positions of their centromeres were established and analysed in the reconstructions of somatic root tip metaphases and cells at mitotic metaphase near their entry into meiosis. Parental genomes tended to lie in spatially separated domains in both tissues. Although varying in morphology, the two sets of chromosomes had similar mean sizes, so size differences did not cause the separation observed. In the EM, the centromere-associated structures of the chromosomes of the more central genome, originating from H. vulgare, were larger than those of the more peripheral genome of H. bulbosum origin.

Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.

Cross-sectional observation of LSI by high resolution TEM

A high density A mega bits DRAM (dynamic random access memory) which was named as FASIC (folded bit line adaptive side wall isolated capacitor cell) was made and reported in 1986. The cell has been fabricated on P-type Si single crystal substrate as four layers (one poly-Si, two poly-silicides and one Al layer) and has a size of 2.6μm × 4.2μm (one million cells in 2.6mm × 4.2mm).Figure 1 shows a light micrograph of a part of FASIC DRAM 6-inch wafer. The unit chip of the circuit in the wafer which is a square of 15mm × 15mm are shown by a circle A. The region indicated by B is the circuit for testing the memory cells and the ones indicated by C and D have 2M and AM memories in 7.5mm × 5mm and 15mm x 5mm respectively. AA' and BB' show two directions rectangular each other. Figure 2 shows schematically the cross-section along AA' direction, which parallel to bit line (BL). The cross sections of word line (WL), A1 line contact and trench (capacitor) are shown. The word line is vertical to bit line and parallel to BB' direction shown in Figure 1.

The Caries Lesion Under the Scanning Acoustic Microscope

The scanning acoustic microscope can be used to obtain images of caries lesions in longitudinal sections of human enamel. The contrast in the acoustic images is unique in that it arises from changes in the elastic properties across the surface of a specimen. The contrast depends sensitively on the distance between the specimen and the focal plane of the lens, and this can be exploited to reveal features of interest. Comparison of an acoustic micrograph, a polarized light micrograph, and a microradiograph of a caries lesion reveals that the elastic properties of enamel are strongly dependent on the level of mineralization within the tissue. Acoustic micrographs show regions similar to those seen with the other techniques, but with greater sensitivity to small changes in mineralization.