A total of sixty surgically castrated male pigs (Large White × Landrace) weighing 31·2 (sd 4·3) kg were used in a randomised block experiment to examine the effect of added dietary inulin (0, 20, 40 and 80 g/kg) on the occurrence of swine dysentery (SD) and on fermentation characteristics in the large intestine after experimental challenge with the causative spirochaete Brachyspira hyodysenteriae. The pigs were allowed to adapt to the diets for 2 weeks before each pig was challenged orally four times with a broth culture containing B. hyodysenteriae on consecutive days. Increasing dietary levels of inulin linearly (P = 0·001) reduced the risk of pigs developing SD; however, eight out of fifteen pigs fed the diet with 80 g/kg inulin still developed the disease. The pH values in the caecum (P = 0·072) tended to decrease, and in the upper colon, the pH values did decrease (P = 0·047) linearly with increasing inulin levels in the diets, most probably due to a linear increase in the concentration of total volatile fatty acids in the caecum (P = 0·018), upper colon (P = 0·001) and lower colon (P = 0·013). In addition, there was a linear reduction in the proportion of the branched-chain fatty acids isobutyric acid and isovaleric acid in the caecum (P = 0·015 and 0·026) and upper colon (P = 0·011 and 0·013) with increasing levels of dietary inulin. In conclusion, the present study showed that a diet supplemented with a high level of inulin (80 g/kg) but not lower levels reduced the risk of pigs developing SD, possibly acting through a modification of the microbial fermentation patterns in the large intestine.

Organized nanostructures are formed after irradiation of layers of randomly aligned single-wall carbon nanotube (SWNT)-polymer composites by a Ti:Sapphire 775 nm laser with a 150 fs pulse at fluences near 0.1 J/cm2. At varying peak fluences morphology is seen where the tubes are ejected from the substrate or formed into long, parallel structures of SWNT’s. These structures have been created on both glass substrates and carbon grids. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) investigation of the structures reveal that they are composed of bundled nanotubes typically 400 nm – 1 micron long. Large-area laser patterning of the film allows for structuring of the film without detrimental decreases in conductivity.

Extended abstract of a paper presented at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, August 1–5, 2004.

The environmental scanning electron microscope (ESEM™) and variable pressure electron microscope (VPSEM) have become accepted tools in the contemporary electron microscopy facility. Their flexibility and their ability to image almost any sample with little, and often no, specimen preparation has proved so attractive that each manufacturer of scanning electron microscopes now markets a low vacuum model.

The University of Michigan Electron Microbeam Analysis Laboratory (EMAL) operates two variable pressure instruments, an ElectroScan E3 ESEM and a Hitachi S3200N VPSEM. The E3 ESEM was acquired in the early 1990s with funding from the Amoco Foundation and it has been used to examine an extremely wide variety of different materials. Since EMAL serves the entire university community, and offers support to neighboring institutions and local industry, the types of materials examined span a wide range. There are users from Materials Science & Engineering, Chemical Engineering, Nuclear Engineering, Electrical Engineering, Physics, Chemistry, Geology, Biology, Biophysics, Pharmacy and Pharmacology.

The development and makeup of a real-time full remote control system for the University of Michigan, Department of Materials Science and Engineering Teaching SEM is described. The instrument was initially controlled via the campus local area Ethernet network and cable TV network. The latest implementation employs Fast Ethernet, Asynchronous Transfer Mode (ATM) networks, and moving picture experts group (MPEG) video encoding to effect the remote control via the computer network alone. Remote control demonstrations from Washington, DC, Dearborn, MI, and Emerson School, Ann Arbor, MI are described.

Since the introduction of personal computers in the early 1980s, most documents and manuscripts have been prepared from within a word processing program on such a computer. Indeed, most documents on personal computers are created on a limited number of word processing packages that have come to dominate the market. Most of the data acquisition that attendees of Microscopy and Microanalysis currently perform is digital, i.e. directly into a personal computer or desktop workstation. It is frequently the case that images, spectra and diffraction patterns are only committed to paper when they are dispatched for publication. With the advent of the World Wide Web in 1994, and its subsequent explosive growth, entirely electronic publishing has become possible. It is possible to envisage the day when most publications will be available solely electronically and material will be only printed out occasionally by the reader.

While there are a growing number of journals that are only available electronically, entirely paperless publication is not yet the norm and there are no definite plans, as yet, to publish the proceedings of the Microscopy and Microanalysis meetings solely in electronic format. However, there are a number of advantages to applying some of these emerging technologies in the production of the future proceedings. Electronic submission of abstracts is one advance that is being considered by the organizers of the meetings scheduled for the early 2000s. The National Science Foundation now receives almost all proposals electronically. There are several reasons for moving to electronic submission. The first is that proofing and correcting the abstracts would then be straightforward.

The environmental scanning electron microscope (Environmental SEM) has proved to be a powerful tool in both materials science and the life sciences. Full characterization of materials in the environmental SEM often requires chemical analysis by X-ray energy dispersive spectroscopy (XEDS). However, the spatial resolution of the XEDS signal can be severely degraded by the gaseous environment in the sample chamber. At an operating pressure of 5Torr a significant fraction of the primary electron beam is scattered after it passes through the final pressure limiting aperture and before it strikes the sample. Bolon and Griffin have both published data that illustrates this effect very well. Bolon revealed that 45% of the primary electron beam was scattered by more than 25 μm in an Environmental SEM operating at an accelerating voltage of 30kV, with a water vapor pressure of 3Torr and a working distance of 15mm.

To introduce engineering undergraduates to microstructural characterization in the scanning electron microscope, The Department of Materials Science and Engineering (MS&E) at The University of Michigan has developed the Teaching SEM. This instrument, based on a Philips XL30 SEM and located in the teaching laboratories, may be controlled from a lecture theater or classroom virtually anywhere on the University campus via a combination of the campus computing network and the campus cable television network. The use of the campus cable TV network is a limitation. Many areas of the University have Internet connections, but no cable connections. A number of local schools have expressed an interest in incorporating use of this system into their classes. The current work seeks to eliminate the cable TV network and send both the control and video signals over the Internet.

The field of in-situ electron microscopy has recently become very active. Microscopy and Microanalysis 1997 was host to an extended symposium devoted entirely to in-situ studies. Also, a recent Winter School sponsored by Arizona State University was devoted entirely to in-situ electron microscopy and drew over 90 attendees. Examination of the presentations and papers in these in-situ symposia has revealed that the researchers involved still have problems acquiring, managing and storing and manipulating their data. An in-situ experiment, by its very nature, is dynamic and recording micrographs is typically not the optimum method of image acquisition. Videotape is the preferred medium. High grade S-video recording of experiments permits the extraction of single frames of reasonable quality from the tapes for presentation and publication. There are, however, a number of problems with video recording. During in-situ studies a number of variables in the sample environment are changing, e.g. the pressure, the temperature, the stress, the strain and the microscope parameters (accelerating voltage, beam current, magnification, specimen tilt, etc.).

The environmental scanning electron microscope (or Environmental SEM) is a powerful tool in the materials science laboratory. The large sample chamber and ability to operate in a very poor vacuum (>5Torr) makes it an ideal device for a wide variety of in-situ studies. A three point bending stage has been used in the ElectroScan E3 environmental SEM at the University of Michigan for over four years. The stage is extremely flexible and can be used to view samples in both planar and transverse views. It also allows for quantitative recording of the stress and strain exerted on the sample via a load cell and a linear variable differential transducer. The output s of the load cell are acquired into an Apple Macintosh computer via a National Instruments analog-to-digital acquisition card. To extend the capability of EMAL's in-situ tensile testing laboratory, a uniaxial tensile stage has been constructed in collaboration with the Department of Mechanical Engineering and Applied Mechanics.

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quality positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).

The correlation between surface cross-hatched morphology and interfacial misfit dislocations in strained III-V semiconductor heteroepitaxy has been studied. The surface pattern is clearly seen on samples grown at high temperature (520°C) and with lattice mismatch f < 2%. A poorly defined cross-hatched morphology is found on layers grown at low temperature (400°C). For f > 2%, a rough textured surface morphology is observed in place of cross hatching. Few threading dislocations are observed in the strained layer when cross hatch develops. Cross hatch occurs after most interfacial misfit dislocations are generated. The results suggest that surface cross hatch is directly related to the generation and glide of interfacial misfit dislocations.