MedWorm provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest medical blog items that have been tagged with 'electron microscopy'. Sat, 03 Sep 2011 02:36:19 +0100 http://www.medworm.com/index.php?rid=3973009&cid=t_100973_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2010%2F09%2F15%2Fupdate-diadem-final-results%2F The DIADEM automated neuronal reconstruction contest has finished.  Accurate, fast, and high-resolution automated neuron reconstruction is of vital importance to cracking the mystery of how neural circuits perform. Even with perfect knowledge of the firing patterns of every cell in a circuit, our understanding of how these patterns are produced and how the information is processed would be quite limited.  True understanding requires knowledge of the precise wiring diagram.  This prize is a good first step towards bringing awareness of this tricky problem to the world’s best computer scientists. $75,000 in prize money was to go to the group that was able to produce high-quality reconstructions of neuronal structures at least 20x faster than by-hand reconstructions.  In the finals... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=3973009 Wed, 15 Sep 2010 19:23:46 +0100 3973009 http://www.medworm.com/index.php?rid=3318545&cid=t_100973_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2010%2F03%2F01%2Fcompressed-sensing-in-neuroscience%2F Wired has a nice lay-person write-up of the rapidly developing field of compressed sensing. This is a technique that allows accurate reconstructions of highly undersampled sparse datasets. This field really took off in 2004 when Emmanuel J. Candès discovered that a tomography phantom image could be reconstructed exactly even with data deemed insufficient by the Nyquist-Shannon criterion. It is probably the hottest topic in imaging theory today. Modified Shepp-Logan phantom with enhanced contrast for visual perception. According to this review, Compressed Sensing MRI, its successful application requires three conditions to be met : Transform Sparsity: The desired image must have a sparse representation in a known transform domain (i.e., it must be compressible by transform coding), I... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=3318545 Mon, 01 Mar 2010 15:03:53 +0100 3318545 http://www.medworm.com/index.php?rid=2268014&cid=t_100973_136_f&fid=37846&url=http%3A%2F%2Fhealthinfoispower.wordpress.com%2F2009%2F03%2F15%2Fcan-fda-approved-hiv-drugs-treat-chemoresistant-ovarian-cancer%2F Two recent in vitro studies conducted in the U.S. and Europe raise a provocative question:  Can FDA-approved human immunodeficiency virus (HIV) drugs be used to treat chemoresistant ovarian cancer?  Both studies were based upon the fact that HIV patients taking antiretroviral inhibitors have a lower incidence of infection-associated malignancies.  Based upon that fact, the researchers [...] (Source: Libby's H*O*P*E*) Libby's H*O*P*E* blogs http://www.medworm.com/rss/comments.php?id=2268014 Mon, 16 Mar 2009 04:26:23 +0100 2268014 http://www.medworm.com/index.php?rid=2190568&cid=t_100973_122_f&fid=34757&url=http%3A%2F%2Fbraintechsci.blogspot.com%2F2009%2F02%2Fconnectomics-segmentation-circuit.html from connectomes.org :The Challenge:Download the images at http://brainmaps.org/index.php?action=viewslides&datid=137 which are SBF-SEM images from mouse hippocampus, and try your best algorithms and software for segmentation and circuit reconstruction. These are important problems to solve because much larger datasets of this type will soon be available as part of the connectomics initiative to map entire brains at synapse resolution. (Source: BrainTechSci) BrainTechSci blogs http://www.medworm.com/rss/comments.php?id=2190568 Mon, 16 Feb 2009 07:13:00 +0100 2190568 http://www.medworm.com/index.php?rid=2026813&cid=t_100973_132_f&fid=35016&url=http%3A%2F%2Fpeanutbutter.wordpress.com%2F2008%2F12%2F09%2Fmelting-away-misconceptions-the-strucure-of-the-mitotic-chromosome%2F I am sure many of you remember sitting in a science class as a child, or an early undergraduate course, being taught about cell replication. How DNA is passed from one cell to the next via either mitosis or meiosis in order to effect DNA replication and gene expression, so that the genetic information content of the DNA can be passed from one generation to the next. DNA can be organised inside packages within cells. These packages are called chromatin, which are found inside the nuclei of eukaryotic cells and the nucleoid of prokaryotic cells. Chromatin [1] is a complex combination of DNA, RNA and protein that forms a chromosome. To date, the commonly accepted hypothesis is that chromatin can take the following three organisational forms DNA wrapping around nucleosomes - The “be... peanutbutter blogs http://www.medworm.com/rss/comments.php?id=2026813 Wed, 10 Dec 2008 11:39:25 +0100 2026813 http://www.medworm.com/index.php?rid=500882&cid=t_100973_122_f&fid=35068&url=http%3A%2F%2Fbrainwindows.wordpress.com%2F2007%2F03%2F25%2Fcshl-meeting-session-vii-super-resolution-optical-techniques%2F Jean-Louis Bessereau – Ultrastructural mapping of functional domains of synapse at the synapse using high pressure imaging High pressure freezing instantaneously converts up to 0.3mm thick water into amorphous ice. C Elegans only .1mm thick at maximum. HPF entire worm to obtain EM of ‘living’ synapses. Vesicle priming occurs within 100nm of presynaptic density, directly across from post receptors. However, vesicle recycling occurs only at sites >150nm lateral from presynaptic release sites. Mark Ellisman – Multiscale light and electron microscopic imaging of the nervous system Two-color correlated light and EM microscopy using FlAsH and ReAsH. Quantum dot immunohistochemistry for multicolor correlated light and EM. QDs of different wavelength are differently sized and can be dis... Brain Windows blogs http://www.medworm.com/rss/comments.php?id=500882 Mon, 26 Mar 2007 07:22:36 +0100 500882 http://www.medworm.com/index.php?rid=471533&cid=t_100973_122_f&fid=34757&url=http%3A%2F%2Fbraintechsci.blogspot.com%2F2007%2F02%2Fsynapse-resolution-whole-brain-atlases.html In conclusion, for purposes of obtaining information about whole-brain connectivity, a nanometer-resolution whole-brain scan is required, and current-day tracer experiments are suboptimal and will always leave room for ambiguities that can only be resolved by completely mapping every synapse and axon in the brain. However, constructing a synapse resolution (or nanometer resolution) whole-brain atlas for even a mouse brain is so formidable as to be seemingly beyond today's technological capabilities. Maybe in 10-20 years. (Source: BrainTechSci) BrainTechSci blogs http://www.medworm.com/rss/comments.php?id=471533 Sat, 24 Feb 2007 23:45:00 +0100 471533