11 research outputs found

    Implementation and Performance of Factorized Backprojection on Low-cost Commercial-Off-The-Shelf Hardware

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    Traditional Synthetic Aperture Radar (SAR) systems are large, complex, and expensive platforms that require significant resources to operate. The size and cost of the platforms limits the potential uses of SAR to strategic level intelligence gathering or large budget research efforts. The purpose of this thesis is to implement the factorized backprojection SAR image processing algorithm in the C++ programming language and test the code\u27s performance on a low cost, low size, weight, and power (SWAP) computer: a Raspberry Pi Model B. For a comparison of performance, a baseline implementation of filtered backprojection is adapted to C++ from pre-existing MATLAB® code. The factorized backprojection algorithm shows a computational improvement factor of 2-3 compared to filtered backprojection. Execution on a single Raspberry Pi is too slow for real-time imaging. However, factorized backprojection is easily parallelized, and we include a discussion of parallel implementation across multiple Pis

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Mutations involved in Aicardi-Goutières syndrome implicate SAMHD1 as regulator of the innate immune response.

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    Aicardi-Goutières syndrome is a mendelian mimic of congenital infection and also shows overlap with systemic lupus erythematosus at both a clinical and biochemical level. The recent identification of mutations in TREX1 and genes encoding the RNASEH2 complex and studies of the function of TREX1 in DNA metabolism have defined a previously unknown mechanism for the initiation of autoimmunity by interferon-stimulatory nucleic acid. Here we describe mutations in SAMHD1 as the cause of AGS at the AGS5 locus and present data to show that SAMHD1 may act as a negative regulator of the cell-intrinsic antiviral response.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Clinical and Molecular Phenotype of Aicardi-Goutières Syndrome

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    Aicardi-Goutières syndrome (AGS) is a genetic encephalopathy whose clinical features mimic those of acquired in utero viral infection. AGS exhibits locus heterogeneity, with mutations identified in genes encoding the 3′→5′ exonuclease TREX1 and the three subunits of the RNASEH2 endonuclease complex. To define the molecular spectrum of AGS, we performed mutation screening in patients, from 127 pedigrees, with a clinical diagnosis of the disease. Biallelic mutations in TREX1, RNASEH2A, RNASEH2B, and RNASEH2C were observed in 31, 3, 47, and 18 families, respectively. In five families, we identified an RNASEH2A or RNASEH2B mutation on one allele only. In one child, the disease occurred because of a de novo heterozygous TREX1 mutation. In 22 families, no mutations were found. Null mutations were common in TREX1, although a specific missense mutation was observed frequently in patients from northern Europe. Almost all mutations in RNASEH2A, RNASEH2B, and RNASEH2C were missense. We identified an RNASEH2C founder mutation in 13 Pakistani families. We also collected clinical data from 123 mutation-positive patients. Two clinical presentations could be delineated: an early-onset neonatal form, highly reminiscent of congenital infection seen particularly with TREX1 mutations, and a later-onset presentation, sometimes occurring after several months of normal development and occasionally associated with remarkably preserved neurological function, most frequently due to RNASEH2B mutations. Mortality was correlated with genotype; 34.3% of patients with TREX1, RNASEH2A, and RNASEH2C mutations versus 8.0% RNASEH2B mutation–positive patients were known to have died (P=.001). Our analysis defines the phenotypic spectrum of AGS and suggests a coherent mutation-screening strategy in this heterogeneous disorder. Additionally, our data indicate that at least one further AGS-causing gene remains to be identified

    Sähkönlaadun ja energiankulutuksen tutkimus

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    Opinnäytetyössä tutkitaan sähkönlaadun ja energiankulutusta Raute Oyj:n rakentamissa vaneri- ja LVL-viilupalkkikoneissa. Opinnäytetyön tarkoituksena on selvittää esiintyykö Raute Oyj:n valmistamissa koneissa sähkönlaatua heikentäviä tekijöitä, kuten harmonisia yliaaltoja. Sähkönlaatua heikentävien tekijöiden lisäksi opinnäytetyössä selvitetään mahdollisuutta moottorikeskusten mitoituksessa käytettävän korjauskertoimen tarkentamiselle. Opinnäytetyön teoriaosassa esitellään sähkönlaatuun vaikuttavia tekijöitä, sekä niiden vaikutuksia sähköverkkoon ja verkonkäyttäjälle. Lisäksi teoriaosassa käydään läpi ratkaisuja, joilla esimerkiksi sähköverkossa esiintyvien yliaaltojen pitoisuutta voidaan vähentää tai poistaa kokonaan. Verkossa esiintyville häiriöille kuten harmonisille yliaalloille, taajuuden ja jännitteen vaihteluille on määritelty rajoituksia standardilla SFS-EN 50160, myös näitä rajoituksia ja niiden vaikutuksia sähkönlaatuun käydään läpi opinnäytetyön teoriaosassa. Sähkönlaatua ja energiankulutusta mitattiin kahdessa Raute Oyj:n koneessa, ja näiden mittaukseen käytettiin Fluken power quality analyzer mallia olevaa mittalaitetta. Mittaustuloksissa huomattiin sähkönlaadun olevan yleisesti hyvällä tasolla ja täyttävän standardissa SFS-EN 50160 sähkönlaadulle määritellyt raja-arvot. Tulosten perusteella huomattiin myös, että joissakin tapauksissa keskusten mitoituksessa käytettäviä korjauskertoimia pystyy tarkentamaan.The study researches the quality of electricity and the energy consumption on plywood and laminated veneer lumber (LVL) machines manufactured by Raute Plc. The Thesis aims to examine the potential existence of factors reducing the quality of electric, such as harmonic waves, on machines manufactured by Raute Plc. In addition to examine the electricity quality and consumption of energy, the thesis looks into the possibility of elaboration of motorcabin’s equalisation. The theory part of the Thesis presents factors that influence electric quality, as well as their influences on the electricity network and network’s users. Additionally, the theory part discusses solutions, which for instance reduce or eliminate harmonic waves in electric network. SFS-EN 50160 standard defines restrictions for disturbance in electric network such as harmonic waves, frequency and voltage variation, these restrictions are also presented in the theory part of the Thesis. In this study, electric quality and energy consumption were measured in two different machines manufactured by Raute Plc, and the measurements were conducted by Fluke power quality analyser measuring device. Electric quality was generally high according to the measurements, and it meets the electric quality standards defined in SFS-EN 50160. The measurements also indicated that in some cases the equalisation is possible to elaborate

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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