It has generally been considered that cereals (such as wheat, rice, and maize) were the first crops to be cultivated by human beings. But a new study that included scanning electron microscopy, by Mordechai Kislev, Anat Hartmann, and Ofer Bar-Yosef (micrographs by Yakov Langsam) provides strong evidence that figs were the first agricultural crop in human history.

Kislev et al. recovered nine fig fruits (plus many nutlets called drupelets) from the ruins of a burned building near Jericho. The fire had carbonized the fruit which helped preserve the morphology of the specimens. The site was radiocarbon dated to 11,400 to 11,200 years ago. Microscopic analysis demonstrated that these specimens were of an edible fig that produces drupelets without embryos; that is, these fruits are sterile. Wild fertile figs have a symbiotic relationship with a wasp that plays an essential role in pollinating the fruit, but this fruit is inedible. In this study, no evidence of wasps or where a wasp could exit the fruit were found and these are features found in wild fruit. In other words, wild figs that can be pollinated and reproduce without human intervention are inedible, but edible figs require human intervention. The specimens examined in this study were of the latter variety.

Material scientists and engineers continue to developmaterials and structures that are ever smaller. Some of this engineering is to simply domore with less while the science of nanomaterials allows new materials to be produced with a novel range of physical and chemical properties due to the small length scales of the microstructural features of thematerials. Currently, nanoscalematerials have been produced with a diverse set of useful properties and can be found in common substances like sunscreen or technologically advanced microelectronic devices. A complete understanding of materials is based on knowledge of the processing used to produce an interesting material coupled with a full characterization of the structure that results. It is this structure/property relationship that is the basis of understanding any newmaterial developed at all length scales.

It is well known that analysis using transmission electron microscopes (TEM) yields very high resolution images of thin specimens. However, the applicability of TEM analysis is not universal due to the requirement that a high internal vacuum is required. This high vacuum precludes the TEM study of living specimens or specimens in a gas or liquid environment. In order to tackle this problem, L. Marton of Universite Libre in Brussels, Belgium was the first to design an environmental cell (E-cell) in 1935 that was sealed in the tip of a TEMsample holder [1]. Marton's design included two 0.5 μm aluminum foils as upper and lower windows sandwiching a biological sample to sustain a living environment. The electron transparent windows permitted the confined biological objects to be imaged in TEMmode. Since then, environmental TEM (E-TEM) has received increasing attention from biological scientists and eventually from materials scientists as well.

Polymers are viscoelastic materials that can often deform during microtome sectioning. Similar to plastic embedded biological materials, many methods have been developed over the years to not only improve the image contrast of these materials but also to harden the material for improved sectioning during microtomy. Even with these improvements, a common artifact, compression, during the sectioning of this class of materials remains problematic.

Compression is caused by several factors: hardness of the sample, embedding media, wedge angle of the knife, interaction between the diamond and sample surface, section thickness and cutting speed. It has been found that reducing the knife angle from 45º to 35° leads to a reduction in compression. Recent efforts to further reduce the compression of ultra-thin sections have led to the invention of an oscillating diamond knife.

Electron microscopy and x-ray microanalysis are common techniques in many research, development and quality labs (Garratt-Reed and Bell, 2002; Goldstein et al., 2003). As systems become ever more automated, as well as easy to use, new applications for the use of these systems develop and expand. One such application is particle analysis. These “particles” might be small loose fragments that can be applied to a conductive adhesive or a filter, embedded in epoxy and polished, or they can be inclusions within collect an EDS spectrum.

Recent advances in nanotechnology and nanoscience are highly dependent on our newly acquired ability to measure and manipulate individual structures on the nanoscale. A drawback of light microscopy is the fundamental limit of the attainable spatial resolution dictated by the laws of diffraction at about 250 nanometers. This diffraction limit arises from the fact that it is impossible to focus light to a spot smaller than half its wavelength. The challenge of breaking this limit has led to the development of near-field scanning optical microscopy (NSOM).

JECP stands for a java electron crystallography project that includes a series of practical java stand-alone programs for electron diffraction/microscopy and crystallography applications. The aim of the JECP project is twofold, i) as teaching tools to show students the principles of electron diffraction/microscopy and crystallography, ii) as research tools to analyze experimental results. Although there are commercial and public domain computer programs available that allow a user to simulate electron diffraction patterns or processingHREMimages, there are always situations when we need to perform operations that are not a feature of any of the existing programs. The programs in the JECP can bemodified and extended tomeet the need in experiments.

The methylotropic yeast Pichia pastoris is a model organism for the study of autophagy and peroxisome biogenesis. Being able to look at the organism via transmission electron microscopy (TEM) can yield valuable data on the morphology of the secretory pathway and many other organelles of interest. However, preparing the yeast for TEM work can be very arduous and costly. One of the reasons P. pastoris is so hard to prepare for visualization is because its cell wall is very thick and tough compared to the membrane of a mammalian cell. Thus, P. pastoris is notoriously difficult to infiltrate with fixatives, a step necessary to maintain its ultrastructure. This article outlines an efficient and cost effective way to prepare P. pastoris for TEM without the need for certain specialized equipment. With this protocol, excellent pictures can be obtained by using the buffers, KMnO4, sorbitol, and PIPES, along with glutaraldehyde. These components preserve the ultrastructure of the yeast without any apparent artifactual change in morphology.

There are numerous biological surfaces covered with secretory fluids, such as the adhesive pads of insects, sticky trichomes of plants, gustatory drops on plant leaves, lubricating coatings of vertebrate joints, etc. These fluids can be well visualised using light microscopy methods, however it is difficult to obtain detailed high magnification ultrastructural information on the morphology of these small-volume droplets. Conventional SEM preparation methods fail, because of the presence of vacuum and/or the instability of the subject fluid under the electron beam. Part of the problem can be resolved by the use of an Environmental SEM (ESEM) or an Atomic Force Microscopy (AFM), but the first method is restricted in its resolution and the second method has difficulty with resolving the complex geometry of the substrate and is rather slow for the analysis of these small, fast-evaporating droplets. Moreover, it is desirable in many applications to visualise the fluid behaviour at the contact interface between two surfaces, and this task cannot be resolved via the conventional application of either SEM or AFM methods. Herewith, we describe a Cryo-SEM approach successfully applied for visualisation of droplets of various fluids deposited on a substrate, or located at the interface between two surfaces.

In science, there are occasions when it is of value to know the number and distribution of different types of particles present in a solution. Calculation of these values is simplified if you can uniformly distribute the number of particles in a known volume over an established surface area. A number of procedures have been proposed. The best which we have used is direct centrifugation of particles to formvar/carbon-formvar coated electron microscope grids in an EM-90 rotor for the Beckman Airfuge®. This instrument makes use of the ability to pellet all material in a suspension using established centrifugation theory.

Jan Hinsch wrote an excellent review article “About the Use of Digital Single Lens Reflex Cameras on Microscopes” in 2004 for the web journal Modern Microscopy, http://www.modernmicroscopy.com/main.asp?article=33&print=true. The purpose of this article is to demonstrate the capabilities of the new Olympus Evolt E-330 DSLR for use with older design microscopes to capture the full diagonal of an 18 mm field number eyepiece that is not high eyepoint. This camera can be fitted with OM mount film camera lenses using the Olympus MF-1 adapter. A key requirement I had before purchasing a DSLR was that critical focusing must be possible at the full resolution of the sensor. I asked the Olympus Precision Instruments Group whether Olympus would have a DSLR available with this capability, and learned from them that the new E-330 DSLR would allow a selected area to be displayed at full resolution from the main CMOS sensor for critical focusing. This 7.5 megapixel sensor measures 13 by 17 mm.

The stereo dissecting microscope is a widely used instrument for macro-structure observation and documentation. The emergence of digital imaging, along with sophisticated imaging software, makes this macro-imaging more efficient. It also makes possible certain special imaging modes that are difficult to accomplish with traditional (film) imaging, such as extended depth of focus imaging ( EDF), automatic mont aging, etc. These special imaging techniques often require dedicated hardware on the microscope, such as a motorized stage.

In a recent paper on the revised formulation of Spurr low viscosity embedding medium with ERL 4221 the importance of maintaining an appropriate anhydride:epoxide (A:E) ratio was discussed. By understanding a few simple concepts about epoxy resin formulations and setting up a formulation table it is possible to create new resin mixtures with good sectioning properties and other desirable properties such as decreased viscosity and increased beam stability.

Before starting a formulation you need to know the molecular weight of the anhydride and the WPE (weight per epoxide equivalent) of the epoxy resin component. The molecular weights and WPEs are usually printed on the bottle or can be obtained from the vendor. An A:E ratio of 0.7:1.0 -1.0:1.0 is used for most biological specimens. Increasing the A:E ratio results in a harder block; decreasing the A:E ratio results in a softer block. Table 1 shows a basic formulation spreadsheet where the molecular weights of the anhydrides and the WPEs of the epoxy resin components can be entered. The A:E ratio is entered under the anhydride for the molar ratio and the molar ratios of the epoxy components are entered under the epoxy components. The calculations are done as shown in each column and row.