Since the establishment of one of the early co-operatives in Western Europe in the 1800s, co-operatives in the Western world have developed exponentially and played essential roles in improving agricultural sustainability. Much research has been carried out on this topic; however, to date, there is no systematic review of this body of the literature. To fill this gap, this paper is designed to identify the main research themes regarding agricultural co-operatives in western countries, and subsequently shed light on avenues for future research in this field. Based on a systematic literature review with bibliometric techniques including citation and co-citation analyses, this study identifies six predominant themes (the social and environmental performance of cooperatives, the governance structures and performance of co-operatives, trust and commitment in co-operatives, comparisons between co-operatives and investor-owned firms (IOFs), financing problems in co-operatives, and women co-operatives) of debates on western co-operatives. Recommendations for future research are finally provided.

The use of in-line digital video holography was demonstrated for observation of the incipient erosion processes in a laboratory experiment using non-cohesive estuarine sediments. Erosion was caused by the impingement of a vertical water jet on the surface of the test bed. Holographic video reconstructions were obtained using an angular spectrum algorithm. The transverse resolution of approximately 25 µm was limited mainly by resolution of the recording camera and image acquisition chain. This procedure is substantially simpler and more convenient than the previously reported use of in-line holography with pulsed laser illumination and photographic recording. Comparisons between photographic and digital holography are discussed.

Digital in-line holography offers some significant advantages over conventional optical holography and microscopy to image biological specimens. By combining holography with digital video microscopy, an in-line holographic video microscope is developed and is capable of recording spatial 3D holographic images of biological specimens, while preserving the time dimension. The system enables high-speed video recording of fast cell movement, such as the rapid movement of blood cells in the blood stream in vivo. This capability is demonstrated with observations of fast 3-D movement of live cells in suspension cultures in response to a gentle shake to the Petri dish. The experimental and numerical procedures are incorporated with a fast reconstruction algorithm for reconstruction of holographic video frames at various planes (z axis) from the hologram and along the time axis. The current system enables both lateral and longitudinal resolutions down to a few micrometers. Postreconstruction processing of background subtraction is utilized to eliminate noise caused by scattered light, thereby enabling visualization of, for example, blood streams of live Xenopos tadpoles. The combination of digital holography and microscopy offers unique advantages for imaging of fast moving cells and other biological particles in three dimensions in vivo with high spatial and temporal resolution.

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