970 research outputs found
Construction of a high-resolution genetic linkage map and comparative genome analysis for the reef-building coral Acropora millepora
Section of Integrative Biology, School of Biological Sciences, University of Texas at Austin, 1 University Station C0930, Austin, TX 78712, USABackground: Worldwide, coral reefs are in decline due to a range of anthropogenic disturbances, and are now also under threat from global climate change. Virtually nothing is currently known about the genetic factors that might determine whether corals adapt to the changing climate or continue to decline. Quantitative genetics studies aiming to identify the adaptively important genomic loci will require a high-resolution genetic linkage map. The phylogenetic position of corals also suggests important applications for a coral genetic map in studies of ancestral metazoan genome architecture.
Results: We constructed a high-resolution genetic linkage map for the reef-building coral Acropora millepora, the first genetic map reported for any coral, or any non-Bilaterian animal. More than 500 single nucleotide polymorphism (SNP) markers were developed, most of which are transferable in populations from Orpheus Island and Great Keppel Island. The map contains 429 markers (393 gene-based SNPs and 36 microsatellites) distributed in 14 linkage groups, and spans 1,493 cM with an average marker interval of 3.4 cM. Sex differences in recombination were observed in a few linkage groups, which may be caused by haploid selection. Comparison of the coral map with other metazoan genomes (human, nematode, fly, anemone and placozoan) revealed synteny regions.
Conclusions: Our study develops a framework that will be essential for future studies of adaptation in coral and it also provides an important resource for future genome sequence assembly and for comparative genomics studies on the evolution of metazoan genome structure.Integrative [email protected]
Real Implementation of Ultrasonic Phased Array Technology Using Advanced Signal Processing Algorithms
Over the past few years, all improvements in the field of ultrasonic non-destructive testing have led to signi-ficant advances in ultrasonic signal processing and image conctruction techniques. The main focus in non-destructive testing area is to improve the resolution of defect dete-ction and make the detection process as fast and accurate as possible. Many techniques have been proposed and imple-mented to improve the flaw and crack detection processes. In general, these techniques can be divided into the two main parts. As first, many proposals consider the const-ruction of ultrasonic transducers and systems. The second part is mainly focused on proposal of efficient signal processing algorithms that improve sensitivity (noise reduction) during ultrasonic signal acquisition. This paper presents our fully developed ultrasonic portable system with implemented phased array technology. All acquired ultrasonic signals are consequently processed using our proposed filtering algorithms
Automated System for Crack Detection using Infrared Thermographic Testing
The objective of this study was the development of the automated system for crack detection on square steel bars used in the automative industry. The automated system for thermographic crack detection uses brief pulsed eddy curr-ents to heat steel components under inspection. Crack, if present, will disturb the current flow and so generate changes in the temperature profile in the crack area. These changes of temperature are visualized using an infrared camera. The image acquired by infrared camera is evaluated through an image processing system. The advan-tages afforede by the system are its inspection times, its excellent flaw detection sensitivity and its ability to detect hidden, subsurface, cracks. The system is part of the inspection line where the subsurface and surface cracks are searched. The system is fully automated and
its ability is to evaluate four meter blocks within 20 seconds. This is the unique reason for using this system in real industrial applications
Fasti Ecclesiae Gallicanae (1200-1500). XIV: Diocèse de Châlons-en-Champagne
This is a prosopographical repertory of bishops, canons and office-holders of the French dioceses from 1200 to 1500, giving for each a biographical and a bibliographical entry. The geographical limits are those of present-day France. Each volume presents the central institutions of the bishopric, and, depending on the availability of sources or research, gives a description of the cathedral borough, books, treasure, relics and ornaments
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Ecological Complexity of Coral Recruitment Processes: Effects of Invertebrate Herbivores on Coral Recruitment and Growth Depends Upon Substratum Properties and Coral Species
Sarah W. Davies, Mikhail V. Matz, Integrative Biology Section, The University of Texas at Austin, Austin, Texas, United States of AmericaSarah W. Davies, Peter D. Vize, Department of Biological Sciences, University of Calgary, Calgary, Alberta, CanadaBackground: The transition from planktonic planula to sessile adult corals occurs at low frequencies and post settlement mortality is extremely high. Herbivores promote settlement by reducing algal competition. This study investigates whether invertebrate herbivory might be modulated by other ecological factors such as substrata variations and coral species identity. Methodology/Principal Findings: The experiment was conducted at the Flower Garden Banks, one of the few Atlantic reefs not experiencing considerable degradation. Tiles of differing texture and orientation were kept in bins surrounded by reef (24 m). Controls contained no herbivores while treatment bins contained urchins (Diadema antillarum) or herbivorous gastropods (Cerithium litteratum). Juvenile corals settling naturally were monitored by photography for 14 months to evaluate the effects of invertebrate herbivory and substratum properties. Herbivory reduced algae cover in urchin treatments. Two genera of brooding coral juveniles were observed, Agaricia and Porites, both of which are common but not dominant on adjacent reef. No broadcast spawning corals were observed on tiles. Overall, juveniles were more abundant in urchin treatments and on vertical, rough textured surfaces. Although more abundant, Agaricia juveniles were smaller in urchin treatments, presumably due to destructive overgrazing. Still, Agaricia growth increased with herbivory and substrata texture-orientation interactions were observed with reduced growth on rough tiles in control treatments and increased growth on vertical tiles in herbivore treatments. In contrast to Agaricia, Porites juveniles were larger on horizontal tiles, irrespective of herbivore treatment. Mortality was affected by substrata orientation with vertical surfaces increasing coral survival. Conclusions/Significance: We further substantiate that invertebrate herbivores play major roles in early settlement processes of corals and highlight the need for deeper understanding of ecological interactions modulating these effects. The absence of broadcast-spawning corals, even on a reef with consistently high coral cover, continues to expose the recruitment failure of these reef-building corals throughout the Caribbean.Natural Sciences and Engineering Research Council of Canada (NSERC) PGS-M to SWD; ACCESS Funding from the University of Calgary to SWD; National Science Foundation grant DEB-1054766 to MVM. Boat time provided by FGBNMS under permit# FGBNMS-2007-006. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Biological Sciences, School ofIntegrative BiologyEmail: [email protected]
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Isolation and characterization of novel green fluorescent proteins from copepods
The isolation and characterization of two protein isoforms collected green fluorescent copepods is described herein. The new Pontella mimocerami GFP-like isoforms pmimGFP1 and pmimGFP2 of the present invention are quick to mature and rapidly produce a fluorescent signal. The two isoforms are very similar in molar extinction coefficients (ME) with 105,000 M−1 cm−1 for pmimGFP1 and 103,000 M−1cm−1 for pmimGFP2, respectively. The relative brightness of these two new copepod GFP-like proteins is the highest measured for any isolated GFP-like protein.Board of Regents, University of Texas Syste
Signal-to-Noise Ratio Improvement based on the Discrete Wavelet Transform in Ultrasonic Defectoscopy
In ultrasonic testing it is very important to recognize the fault echoes buried in a noisy signal. The fault echo characterizes a flaw in the material. An important requirement on ultrasonic signal filtering is zero-time shift, because the position of ultrasonic echoes is essential. This requirement is accomplished using the discrete wavelet transform (DWT), which is used for reducing the signal-to-noise ratio. This paper evaluates the quality of filtering using the discrete wavelet transform. Additional computer simulations of the proposed algorithms are presented
Signal Separation in Ultrasonic Non-Destructive Testing
In ultrasonic non-destructive testing the signals characterizing the material structure are commonly evaluated. The sensitivity and resolution of ultrasonic systems is limited by the backscattering and electronic noise level commonly contained in the acquired ultrasonic signals. For this reason, it is very important to use appropriate advanced signal processing methods for noise reduction and signal separation. This paper compares algorithms used for efficient noise reduction in ultrasonic signals in A-scan. Algorithms based on the discrete wavelet transform and the Wiener filter are considered. Part of this paper analyses and applies blind source separation, which has never been used in practical ultrasonic non-destructive testing. All proposed methods are evaluated on both simulated and acquired ultrasonic signals.
Gene Expression Associated with White Syndromes in a Reef Building Coral, \u3ci\u3eAcropora hyacinthus\u3c/i\u3e
Background: Corals are capable of launching diverse immune defenses at the site of direct contact with pathogens, but the molecular mechanisms of this activity and the colony-wide effects of such stressors remain poorly understood. Here we compared gene expression profiles in eight healthy Acropora hyacinthus colonies against eight colonies exhibiting tissue loss commonly associated with white syndromes, all collected from a natural reef environment near Palau. Two types of tissues were sampled from diseased corals: visibly affected and apparently healthy. Results: Tag-based RNA-Seq followed by weighted gene co-expression network analysis identified groups of co-regulated differentially expressed genes between all health states (disease lesion, apparently healthy tissues of diseased colonies, and fully healthy). Differences between healthy and diseased tissues indicate activation of several innate immunity and tissue repair pathways accompanied by reduced calcification and the switch towards metabolic reliance on stored lipids. Unaffected parts of diseased colonies, although displaying a trend towards these changes, were not significantly different from fully healthy samples. Still, network analysis identified a group of genes, suggestive of altered immunity state, that were specifically up-regulated in unaffected parts of diseased colonies. Conclusions: Similarity of fully healthy samples to apparently healthy parts of diseased colonies indicates that systemic effects of white syndromes on A. hyacinthus are weak, which implies that the coral colony is largely able to sustain its physiological performance despite disease. The genes specifically up-regulated in unaffected parts of diseased colonies, instead of being the consequence of disease, might be related to the originally higher susceptibility of these colonies to naturally occurring white syndromes
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