3,641 research outputs found
TALON - The Telescope Alert Operation Network System: Intelligent Linking of Distributed Autonomous Robotic Telescopes
The internet has brought about great change in the astronomical community,
but this interconnectivity is just starting to be exploited for use in
instrumentation. Utilizing the internet for communicating between distributed
astronomical systems is still in its infancy, but it already shows great
potential. Here we present an example of a distributed network of telescopes
that performs more efficiently in synchronous operation than as individual
instruments. RAPid Telescopes for Optical Response (RAPTOR) is a system of
telescopes at LANL that has intelligent intercommunication, combined with
wide-field optics, temporal monitoring software, and deep-field follow-up
capability all working in closed-loop real-time operation. The Telescope ALert
Operations Network (TALON) is a network server that allows intercommunication
of alert triggers from external and internal resources and controls the
distribution of these to each of the telescopes on the network. TALON is
designed to grow, allowing any number of telescopes to be linked together and
communicate. Coupled with an intelligent alert client at each telescope, it can
analyze and respond to each distributed TALON alert based on the telescopes
needs and schedule.Comment: Presentation at SPIE 2004, Glasgow, Scotland (UK
SkyDOT (Sky Database for Objects in the Time Domain): A Virtual Observatory for Variability Studies at LANL
The mining of Virtual Observatories (VOs) is becoming a powerful new method
for discovery in astronomy. Here we report on the development of SkyDOT (Sky
Database for Objects in the Time domain), a new Virtual Observatory, which is
dedicated to the study of sky variability. The site will confederate a number
of massive variability surveys and enable exploration of the time domain in
astronomy. We discuss the architecture of the database and the functionality of
the user interface. An important aspect of SkyDOT is that it is continuously
updated in near real time so that users can access new observations in a timely
manner. The site will also utilize high level machine learning tools that will
allow sophisticated mining of the archive. Another key feature is the real time
data stream provided by RAPTOR (RAPid Telescopes for Optical Response), a new
sky monitoring experiment under construction at Los Alamos National Laboratory
(LANL).Comment: to appear in SPIE proceedings vol. 4846, 11 pages, 5 figure
B mu G@Sbase-a microbial gene expression and comparative genomic database
The reducing cost of high-throughput functional genomic technologies is creating a deluge of high volume, complex data, placing the burden on bioinformatics resources and tool development. The Bacterial Microarray Group at St George's (BÎĽG@S) has been at the forefront of bacterial microarray design and analysis for over a decade and while serving as a hub of a global network of microbial research groups has developed BÎĽG@Sbase, a microbial gene expression and comparative genomic database. BÎĽG@Sbase (http://bugs.sgul.ac.uk/bugsbase/) is a web-browsable, expertly curated, MIAME-compliant database that stores comprehensive experimental annotation and multiple raw and analysed data formats. Consistent annotation is enabled through a structured set of web forms, which guide the user through the process following a set of best practices and controlled vocabulary. The database currently contains 86 expertly curated publicly available data sets (with a further 124 not yet published) and full annotation information for 59 bacterial microarray designs. The data can be browsed and queried using an explorer-like interface; integrating intuitive tree diagrams to present complex experimental details clearly and concisely. Furthermore the modular design of the database will provide a robust platform for integrating other data types beyond microarrays into a more Systems analysis based future
RAPTOR observations of delayed explosive activity in the high-redshift gamma-ray burst GRB 060206
The RAPid Telescopes for Optical Response (RAPTOR) system at Los Alamos
National Laboratory observed GRB 060206 starting 48.1 minutes after gamma-ray
emission triggered the Burst Alert Telescope (BAT) on-board the Swift
satellite. The afterglow light curve measured by RAPTOR shows a spectacular
re-brightening by ~1 mag about 1 h after the trigger and peaks at R ~ 16.4 mag.
Shortly after the onset of the explosive re-brightening the OT doubled its flux
on a time-scale of about 4 minutes. The total R-band fluence received from GRB
060206 during this episode is 2.3e-9 erg/cm2. In the rest frame of the burst (z
= 4.045) this yields an isotropic equivalent energy release of ~0.7e50 erg in
just a narrow UV band 130 +/- 22 nm. We discuss the implications of RAPTOR
observations for untriggered searches for fast optical transients and studies
of GRB environments at high redshift.Comment: Submitted to ApJ Letter
A scalable machine-learning approach to recognize chemical names within large text databases
MOTIVATION: The use or study of chemical compounds permeates almost every scientific field and in each of them, the amount of textual information is growing rapidly. There is a need to accurately identify chemical names within text for a number of informatics efforts such as database curation, report summarization, tagging of named entities and keywords, or the development/curation of reference databases. RESULTS: A first-order Markov Model (MM) was evaluated for its ability to distinguish chemical names from words, yielding ~93% recall in recognizing chemical terms and ~99% precision in rejecting non-chemical terms on smaller test sets. However, because total false-positive events increase with the number of words analyzed, the scalability of name recognition was measured by processing 13.1 million MEDLINE records. The method yielded precision ranges from 54.7% to 100%, depending upon the cutoff score used, averaging 82.7% for approximately 1.05 million putative chemical terms extracted. Extracted chemical terms were analyzed to estimate the number of spelling variants per term, which correlated with the total number of times the chemical name appeared in MEDLINE. This variability in term construction was found to affect both information retrieval and term mapping when using PubMed and Ovid
Comparison of a SiO2-CaO-ZnO-SrO Glass Polyalkenoate Cement to Commercial Dental Materials: Ion Release, Biocompatibility and Antibacterial Properties
Ion Release and biocompatibility of a CaO-SrO-ZnO-SiO2 (BT 101) based glass polyalkenoate cement (GPC) was compared against commercial GPCs, Fuji IX and Ketac Molar. The radiopacity (R) was similar for each material, 2.0-2.8. Ion release was evaluated on each material over 1, 7, 30 and 90 days. BT 101 release included Ca (23 mg/L), Sr (23 mg/L) Zn (13 mg/L), Si (203 mg/L). Fuji IX release includes Ca (0.7 mg/L), Al (3 mg/L) Si (26 mg/L), Na (60 mg/L) and P (0.5 mg/L) while Ketac Molar release includes Ca (1 mg/L), Al (0.6 mg/L) Si (23 mg/L), Na (76 mg/L) and P (0.7 mg/L). Simulated body fluid trials revealed CaP surface precipitation on BT 101. No evidence of precipitation was found on Fuji IX or Ketac Molar. Cytotoxicity testing found similar cell viability values for each material (~60 %, P = 1.000). Antibacterial testing determined a reduced CFU count with BT 101 (2.5 x 103) when compared to the control bacteria (2.4 x 104), Fuji IX (1.5 x 104) and Ketac Molar (1.2 x 104). © 2013 Springer Science+Business Media New York
CO2 induced seawater acidification impacts sea urchin larval development I: Elevated metabolic rates decrease scope for growth and induce developmental delay
Anthropogenic CO(2) emissions are acidifying the world's oceans. A growing body of evidence is showing that ocean acidification impacts growth and developmental rates of marine invertebrates. Here we test the impact of elevated seawater pCO(2) (129Pa, 1271 atm) on early development, larval metabolic and feeding rates in a marine model organism, the sea urchin Strongylocentrotus purpuratus. Growth and development was assessed by measuring total body length, body rod length, postoral rod length and posterolateral rod length. Comparing these parameters between treatments suggests that larvae suffer from a developmental delay (by ca. 8%) rather than from the previously postulated reductions in size at comparable developmental stages. Further, we found maximum increases in respiration rates of +100% under elevated pCO(2), while body length corrected feeding rates did not differ between larvae from both treatments. Calculating scope for growth illustrates that larvae raised under high pCO(2) spent an average of 39 to 45% of the available energy for somatic growth, while control larvae could allocate between 78 and 80% of the available energy into growth processes. Our results highlight the importance of defining a standard frame of reference when comparing a given parameter between treatments, as observed differences can be easily due to comparison of different larval ages with their specific set of biological characters
The Structural Characterization of Ga 2O 3-Na 2O-CaO-ZnO-SiO 2 Bioactive Glasses
The characterization of bioactive glasses in which zinc (Zn) has been incrementally replaced by gallium (Ga). © 2012 IEEE
Relating PH and Ion Release from Ga2O3-Na 2O-CaO-ZnO-SiO2 Bioactive Glasses
Three glasses were designed for this study, including one Ga-free glass (Control), and two Ga-containing glasses (TGa-1, TGa-2). In the Ga-containing glasses, Ga2O3 is included at the expense of ZnO. This study focuses on the relation between pH and ion concentration present in solution in which these bioactive glasses have been submerged for periods of 1, 7, and 14 days. © 2013 IEEE
Spectroscopic Insights into the Nano-Bio Interface
Engineered nanomaterials (ENMs) strongly interact with biomolecules due to their unique physicochemical properties. From the standpoint of nanotoxicity, it is imperative to achieve a comprehensive understanding of various nano-bio interactions to ultimately design benign ENMs that do not elicit adverse physiological responses. Spectroscopic tools are ideal for elucidating the underlying biophysical mechanisms of nano-bio interactions. In this chapter, we review spectroscopy techniques, such as Raman, infrared, circular dichroism (CD), and hyperspectral imaging, to illuminate the nano-bio interface. Particularly, we discuss the role of spectroscopic tools in gaining a fundamental understanding of the formation and influence of protein corona on ENM physiological responses
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