Optically Selected GRB Afterglows, a Real Time Analysis System at the CFHT

We attempt to detect optical GRB afterglows on images taken by the Canada France Hawaii Telescope for the Very Wide survey, component of the Legacy Survey. To do so, a Real Time Analysis System called "Optically Selected GRB Afterglows" has been installed on a dedicated computer in Hawaii. This pipeline automatically and quickly analyzes Megacam images and extracts from them a list of variable objects which is displayed on a web page for validation by a member of the collaboration. The Very Wide survey covers 1200 square degrees down to i'=23.5. This paper briefly explain the RTAS process.Comment: 4 pages, 3 figures, accepted for publication in Il Nuovo Ciment

Identifying Barriers to File Rendering in Bit-level Preservation Repositories: A Preliminary Approach

This paper seeks to advance digital preservation theory and practice by presenting an evidence-based model for identifying barriers to digital content rendering within a bit-level preservation repository. It details the results of an experiment at the University of Illinois at Urbana-Champaign library, where the authors procured a random sample of files from their institution’s digital preservation repository and tested their ability to open said files using software specified in local policies. This sampling regime furnished a preliminary portrait of local file rendering challenges, and thus preservation risk, grounded not in nominal preferences for one format’s characteristics over another, but in empirical evidence of what types of files present genuine barriers to staff and patron access. This research produced meaningful diagnostic data to inform file format policymaking for the repository. Data files created to support this research are available at http://hdl.handle.net/2142/89994.Ope

Melanosomes at a glance

Melanosomes, the pigment granules that provide tissues with colour and photoprotection, are the cellular site of synthesis, storage and transport of melanin pigments. They are synthesised in mammalian skin melanocytes, in choroidal melanocytes and retinal pigment epithelial (RPE) cells in the eye, and in melanophores (a class of pigment-containing cells) in lower vertebrates. The precise fate and functions of melanosomes vary according to cell type – epidermal melanocytes supply neighbouring keratinocytes with melanosomes, which results in the pigmentation of skin and hair, whereas pigment granules are retained intracellularly in RPE cells and choroidal melanocytes. In lower vertebrates, the reversible aggregation and dispersion of melanosomes throughout the melanophore enables rapid colour change and adaptation to the environment

Low-complexity wavelet-based scalable image & video coding for home-use surveillance

We study scalable image and video coding for the surveillance of rooms and personal environments based on inexpensive cameras and portable devices. The scalability is achieved through a multi-level 2D dyadic wavelet decomposition featuring an accurate low-cost integer wavelet implementation with lifting. As our primary contribution, we present a modification to the SPECK wavelet coefficient encoding algorithm to significantly improve the efficiency of an embedded system implementation. The modification consists of storing the significance of all quadtree nodes in a buffer, where each node comprises several coefficients. This buffer is then used to efficiently construct the code with minimal and direct memory access. Our approach allows efficient parallel implementation on multi-core computer systems and gives a substantial reduction of memory access and thus power consumption. We report experimental results, showing an approximate gain factor of 1,000 in execution time compared to a straightforward SPECK implementation, when combined with code optimization on a common digital signal processor. This translates to 75 full color 4CIF 4:2:0 encoding cycles per second, clearly demonstrating the realtime capabilities of the proposed modification

A journey through the exocytic pathway

International audienc

Recycling endosomes

The endocytic and exocytic system is important for cells to communicate with their surroundings. For instance, endocytosis allows the regulated internalisation of receptors (which can be ligand bound or not) into peripheral early endosomes and can thus modulate responses to external stimuli. Internalised molecules can be degraded after entering the late-endosomal/lysosomal pathway or be recycled to the cell surface (Maxfield and McGraw, 2004). Recycling to the cell surface can occur directly from peripheral early endosomes. However, many cells display a distinct subpopulation of endosomes that have a slightly higher pH of ~6.4 and also recycle membrane components. These are typically located deeper in the cell and centered around the microtubule-organising centre (MTOC) (Perret et al., 2005). These so-called recycling endosomes (REs) display a heterogeneous tubular-vesicular morphology, which suggests dynamic and intense trafficking activity, and connect the endocytic pathway to the exocytic pathway (Ang et al., 2004; Lock and Stow, 2005; Murray et al., 2005). The most prominent RE marker to date is the small GTPase Rab11. Studies of the function of Rab11 and the proteins with which it interacts in various experimental systems and organisms suggest that cells use REs for the delivery of membranes to regions of their surface that are subject to dynamic reorganisation, probably through regulated interactions with the exocyst, a multiprotein complex containing the Sec5, Sec6, Sec8, Sec10, Sec15 and Exo70 proteins that is thought to recruit material to areas of membrane growth. Consequently, REs are implicated in the regulation of a variety of cellular processes that depend on such trafficking. Several of these are highlighted in the poster and discussed briefly below. Epithelial cell-cell adhesion E-cadherin-mediated cell-cell adhesion controls epithelial cell polarisation, 1679Cell Science at a Glance (See poster insert

The Spatial Vision Tree: A Generic Pattern Recognition Engine- Scientific Foundations, Design Principles, and Preliminary Tree Design

New foundational ideas are used to define a novel approach to generic visual pattern recognition. These ideas proceed from the starting point of the intrinsic equivalence of noise reduction and pattern recognition when noise reduction is taken to its theoretical limit of explicit matched filtering. This led us to think of the logical extension of sparse coding using basis function transforms for both de-noising and pattern recognition to the full pattern specificity of a lexicon of matched filter pattern templates. A key hypothesis is that such a lexicon can be constructed and is, in fact, a generic visual alphabet of spatial vision. Hence it provides a tractable solution for the design of a generic pattern recognition engine. Here we present the key scientific ideas, the basic design principles which emerge from these ideas, and a preliminary design of the Spatial Vision Tree (SVT). The latter is based upon a cryptographic approach whereby we measure a large aggregate estimate of the frequency of occurrence (FOO) for each pattern. These distributions are employed together with Hamming distance criteria to design a two-tier tree. Then using information theory, these same FOO distributions are used to define a precise method for pattern representation. Finally the experimental performance of the preliminary SVT on computer generated test images and complex natural images is assessed

An In-Depth Look at Fractal Image Compression

Ordinary things that we take for granted, such as the nature surrounding us, are extraordinary fractals in the eyes of mathematicians