An Unconventional Flavivirus and Other RNA Viruses in the Sea Cucumber (Holothuroidea; Echinodermata) Virome

Sea cucumbers (Holothuroidea; Echinodermata) are ecologically significant constituents of benthic marine habitats. We surveilled RNA viruses inhabiting eight species (representing four families) of holothurian collected from four geographically distinct locations by viral metagenomics, including a single specimen of Apostichopus californicus affected by a hitherto undocumented wasting disease. The RNA virome comprised genome fragments of both single-stranded positive sense and double stranded RNA viruses, including those assigned to the Picornavirales, Ghabrivirales, and Amarillovirales. We discovered an unconventional flavivirus genome fragment which was most similar to a shark virus. Ghabivirales-like genome fragments were most similar to fungal totiviruses in both genome architecture and homology and had likely infected mycobiome constituents. Picornavirales, which are commonly retrieved in host-associated viral metagenomes, were similar to invertebrate transcriptome-derived picorna-like viruses. The greatest number of viral genome fragments was recovered from the wasting A. californicus library compared to the asymptomatic A. californicus library. However, reads from the asymptomatic library recruited to nearly all recovered wasting genome fragments, suggesting that they were present but not well represented in the grossly normal specimen. These results expand the known host range of flaviviruses and suggest that fungi and their viruses may play a role in holothurian ecology.

STRENGTHENING METHOD AND STRUCTURAL PERFORMANCE OF COLD-FORMED CUT-CURVED STEEL UNDER COMPRESSION

Cold-formed steel section (CFSS) is a popular material in the steel structure that has been recognised in construction work. CFSS with curved section is a new section that proposed in the CFSS and still being studied by researchers. Steel curved section, whether by using hot-rolled or cold-formed steel become essential and significant in the design that be suited by the architectural demand. For this reason, the CFSS is recommended to provide the curve in the structure and dispute the use of the hot-rolled steel. In the study, the CFSS is curved by using a clamp, small bender and welding machine. Through this process, CFSS with cut-curved (CFSS-C) is strengthened by welding in particular location at flange and web. The CFSS-C are established into five specimens with different of welding location and added with one normal specimen (CFSS-N) as a control specimen. The CFSS is tested for the structural performance of the column specimens with the height, 1000 mm under compression load and lastly the suitable strengthens method with highest of ultimate load is selected. From the testing, CFSS-C4 is reported to decrease about 32.26 % when compared with normal specimen.

Trauma Laparotomy: Evaluating the Necessity of Histological Examination

Trauma laparotomy is the most commonly performed procedure in the acute care setting. As current practice, removed specimens are sent for histological examination. A retrospective review of all trauma laparotomies with specimens removed and sent to pathology during a 12-month period was performed in a Level I trauma center. One hundred five procedures of 244 trauma laparotomies yielded specimens sent for examination. Eighty-six patients were male and 19 patients were female with an average age of 34 ± 14 years. Fifty-six per cent of the injuries resulted from penetrating trauma and 44 per cent were from blunt trauma. Gunshot wound and motor vehicle crash were the most common penetrating and blunt injuries, respectively. One hundred thirteen specimens were sent to pathology. Forty-three per cent of the specimens were spleen, 24 per cent small bowel, 16 per cent large bowel, 4 per cent kidney, 2 per cent omentum, 3 per cent appendix, 3 per cent pancreas, and 1 per cent for gallbladder and lung. One hundred twelve of 113 grossly normal specimens had normal pathology. One grossly normal specimen exposed abnormal pathology revealing benign appendiceal mucocele. Therefore, 99.1 per cent of grossly normal specimens sent for histological examination after trauma laparotomy were normal. Based on our review, in select patients routine histological examination of tissues removed for traumatic injury is unnecessary.

Effect of Machining Process on Stable Crack Growth

This paper aims to present an experimental evidence of the effect of machining process on stable crack growth behaviour (SCG) through AISI 4340 low alloy steel. Brittle fracture behaviour had been discovered in a batch of compact tension CT specimens, unlike previous batches that had shown ductile (stable crack growth) behaviour. This was unexpected, and indeed, was anomalous. An investigation was thus carried out to understand what processes that have affected the behaviour. Such anomalous brittle behaviour was observed while performing the fracture test on the affected specimen. The load-load displacement (P-ΔLL) curves show that the “normal” specimen exhibiting stable crack growth and the non-linear region, in the anomalous curve of the anomalous specimens, is rather limited. This indicates very limited, if any, stable crack growth. Fracture tests were carried out on CT specimens with different heat treatments to find the cause of this unexpected embrittlement. Microhardness measurements, tensile tests and microscopic (SEM) examination were also carried out and reported. The results suggest that, a great attention is needed during machining process to avoid accidental changes in the properties and to avoid misleading experimental results.

Reconstruction of electron holograms recorded in a non-FEG, non-biprism TEM

An experimental technique for performing electron holography using a non-FEG, non-biprism transmission electron microscope (TEM) has been introduced by Ru et al. A double stacked specimens, one being a single crystal foil and the other the specimen, are loaded in the normal specimen position in TEM. The single crystal, which is placed onto the specimen, is responsible to produce two beams that are equivalent to two virtual coherent sources illuminating the specimen beneath, thus, permitting electron holography of the specimen. In this paper, the imaging theory of this technique is described. Procedures are introduced for digitally reconstructing the holograms.

Identification of Asbestos Fibres in a Water Sample by X-Ray Microanalysis

Investigation of the particulate matter contained in the water sample, revealed the presence of a number of different types and certain of these were selected for analysis.An A.E.I. Corinth electron microscope was modified to accept a Kevex Si (Li) detector. To allow for existing instruments to be readily modified, this was kept to a minimum. An additional port is machined in the specimen region to accept the detector, with the liquid nitrogen cooling dewar conveniently housed in the left hand cupboard adjacent to the microscope column. Since background radiation leads to loss in the sensitivity of the instrument, great care has been taken to reduce this effect by screening and manufacturing components that are near the specimen from material of low atomic number. To change from normal transmission imaging to X-ray analysis, the special 4-position specimen rod is inserted through the normal specimen airlock.

Metal Cutting in the Scanning Electron Microscope

One of neglected features of a SEM is its applicability to mechanical testing and deformation processes. Metal cutting plastic deformations can be viewed at high magnification with slow deformation rates in the TV mode (rapid scan) in standard SEM-TV setups. Two force or orthogonal cutting as shown in Figure 1 can be performed in situ in a specially designed deformation stage which can be substituted for the normal specimen holder (in the JEOL JSM U3) and inserted in the goniometer stage. The deformation stage is driven externally by a motor connected to a rod which passes through the specimen air lock door and feeds the workpiece. Figures 2 and 3 show stop action micrographs of a metal cutting process as performed in the SEM under normal vacuum conditions. Thus, this large strain, high strain process could be dynamically studied and recorded at magnifications up to 5000X.

Strobilation in a Mollusc; The Development of Aberrant Stages in Clio Pyramidata Linnaeus, 1767 (Gastropoda, Pteropoda)

The occurrence of aberrant stages in the protandric hermaphrodite Clio pyramidata is considered in relation to the sexual cycle of this species. The anatomy of the juveniles, males and females is shortly discussed especially with regard to their sexual organs. The anatomy of the developing (the normal-complete) and of the growing-aberrant stage is briefly reviewed. It is shown that the aberrant stage is formed by strobilation of a normal specimen, probably as a result of less favourable environmental conditions. As the most important conclusions it can be stated that: 1) the aberrant stage described by van der Spoel (1962) is a normal stage in the life cycle; 2) the aberrants are most abundant in the population in the months before the reproductive peaks; 3) the aberrants seem to occur more frequently when environmental conditions become less favourable; 4) the aberrants develop from specimens in the female phase; 5) the aberrants develop into male specimens; 6) the aberrants arise by strobilation of a normal specimen; 7) the animal, which gives rise by strobilation to an aberrant, is after strobilation an asexual shell-less specimen; 8) the strobilation points to an evolutionary relation between worms and molluscs.

A 700°C Hot Stage for the JEOL JSM-2 Scanning Electron Microscope

A heating device compatible with the standard JSM-2 goniometer stage has been developed, thereby providing rapid interchangeability between normal and hot stage microscopy. The hot stage is designed for temperatures ranging from 25 to 700°C and requires only minor modification to and interference with normal microscope functions. The heating carriage is inserted or removed through the airlock like a normal specimen holder; power and thermocouple leads are connected through the standard instrument patch board, and the main structural components consist of stainless steel, copper, nickel and sapphire. Other important internal components of this system include a large cryogenic surface above the specimen carriage and a water chilled base plate which replaces the normal solid dovetail plate. Externally, a direct current power source and a recorder to monitor temperature are required.Fig. 1 shows the arrangement of the heating device and electrical contacts. The hot stage consists of a carriage with the normal dovetail runners which supports the heating device, thermal shielding structure, and electrical connections.

Hydration Stages—Achievements and Obstacles

As we have previously reported our laboratory has developed and perfected a dynamically pumped hydration stage. The stage consists of four collinear apertures: two 100μ and two 200μ. The two 100μ apertures straddle the specimen and define the specimen chamber. The two 200μ apertures define the intermediate chamber which is independently pumped by a normal cryotrapped forepump. The whole stage is translated in order to move the apertures collinear with the beam by the normal specimen translation mechanism, through the bore of the upper polepiece. The specimen may be moved within its 1.2mm gap by an independent translation mechanism thereby allowing the full area of the grid to be examined. Water vapor evaporates from the source and continuously flows out of the apertures thereby providing a very effective anticontamination device.