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Seismic data clustering management system
This is the abstract of the paper given at the conference. Copyright @ 2011 The Authors.Over the last years, seismic images have increasingly played a vital role to the study of earthquakes. The large volume of seismic data that has been accumulated has created the need to develop sophisticated systems to manage this kind of data. Seismic interpretation can play a much more active role in the evaluation of large volumes of data by providing at an early stage vital information relating to the framework of potential producing levels. [1] This work presents a novel method to manage and analyse seismic data. The data is initially turned into clustering maps using clustering techniques [2] [3] [4] [5] [6], in order to be analysed on the platform. These clustering maps can then be analysed with the friendly-user interface of Seismic 1 which is based on .Net framework architecture [7]. This feature permits the porting of the application in any Windows – based computer as also to many other Linux based environments, using the Mono project functionality [8], so it can run an application using the No-Touch Deployment [7]. The platform supports two ways of processing seismic data. Firstly, a fast multifunctional version of the classical region-growing segmentation algorithm [9], [10] is applied to various areas of interest permitting their precise definition and labelling. Moreover, this algorithm is assigned to automatically allocate new earthquakes to a particular cluster based upon the magnitude of the centre of gravity of the existing clusters; or create a new cluster if all centers of gravity are above a predefined by the user upper threshold point. Secondly, a visual technique is used to record the behaviour of a cluster of earthquakes in a designated area. In this way, the system functions as a dynamic temporal simulator which depicts sequences of earthquakes on a map [11]
A new approach to analysing HST spatial scans: the transmission spectrum of HD 209458 b
The Wide Field Camera 3 (WFC3) on Hubble Space Telescope (HST) is currently
one of the most widely used instruments for observing exoplanetary atmospheres,
especially with the use of the spatial scanning technique. An increasing number
of exoplanets have been studied using this technique as it enables the
observation of bright targets without saturating the sensitive detectors. In
this work we present a new pipeline for analyzing the data obtained with the
spatial scanning technique, starting from the raw data provided by the
instrument. In addition to commonly used correction techniques, we take into
account the geometric distortions of the instrument, whose impact may become
important when combined to the scanning process. Our approach can improve the
photometric precision for existing data and also push further the limits of the
spatial scanning technique, as it allows the analysis of even longer spatial
scans. As an application of our method and pipeline, we present the results
from a reanalysis of the spatially scanned transit spectrum of HD 209458 b. We
calculate the transit depth per wavelength channel with an average relative
uncertainty of 40 ppm. We interpret the final spectrum with T-Rex, our fully
Bayesian spectral retrieval code, which confirms the presence of water vapor
and clouds in the atmosphere of HD 209458 b. The narrow wavelength range limits
our ability to disentangle the degeneracies between the fitted atmospheric
parameters. Additional data over a broader spectral range are needed to address
this issue.Comment: 13 pages, 15 figures, 7 tables, Accepted for publication in Ap
An evaluation of immunoreactivity for c-erbB-2 protein as a marker of poor short-term prognosis in breast cancer.
Eighty-five breast carcinomas from the same number of patients have been assessed immunohistochemically using the antiserum 21N for the presence of the c-erbB-2 protein. Twenty-two of the patients had evidence of advanced disease (tumour fixation or distant metastases) at presentation. Follow-up was for a median of 24 months. c-erbB-2 protein was detected in the majority of cells in 14 (16.5%) carcinomas, and to a lesser extent in a further six (7%) tumours. There was no relationship between staining and stage, node status or size but more poorly differentiated carcinomas had evidence of staining (36%) than well (17%) or moderately (14%) differentiated carcinomas (P = 0.02). There was a significant association between staining and mortality (P = 0.009) and recurrence (P = 0.0002). The relative risk of death for staining compared to no staining (after adjusting for node status, stage and grade) was 2.97 (95% confidence interval 1.29, 6.84) and the relative risk of recurrence for staining compared to no staining after similar adjustment was 3.85 (95% confidence interval 1.86-7.97). In this particular group of patients immunoreactivity for c-erbB-2 protein is an independent indicator of poor short-term prognosis
Detection of an atmosphere around the super-Earth 55 Cancri e
We report the analysis of two new spectroscopic observations of the
super-Earth 55 Cancri e, in the near infrared, obtained with the WFC3 camera
onboard the HST. 55 Cancri e orbits so close to its parent star, that
temperatures much higher than 2000 K are expected on its surface. Given the
brightness of 55 Cancri, the observations were obtained in scanning mode,
adopting a very long scanning length and a very high scanning speed. We use our
specialized pipeline to take into account systematics introduced by these
observational parameters when coupled with the geometrical distortions of the
instrument. We measure the transit depth per wavelength channel with an average
relative uncertainty of 22 ppm per visit and find modulations that depart from
a straight line model with a 6 confidence level. These results suggest
that 55 Cancri e is surrounded by an atmosphere, which is probably
hydrogen-rich. Our fully Bayesian spectral retrieval code, T-REx, has
identified HCN to be the most likely molecular candidate able to explain the
features at 1.42 and 1.54 m. While additional spectroscopic observations
in a broader wavelength range in the infrared will be needed to confirm the HCN
detection, we discuss here the implications of such result. Our chemical model,
developed with combustion specialists, indicates that relatively high mixing
ratios of HCN may be caused by a high C/O ratio. This result suggests this
super-Earth is a carbon-rich environment even more exotic than previously
thought.Comment: 10 pages, 10 figures, 4 tables, Accepted for publication in Ap
Agrammatic but numerate
A central question in cognitive neuroscience concerns the extent to
which language enables other higher cognitive functions. In the
case of mathematics, the resources of the language faculty, both
lexical and syntactic, have been claimed to be important for exact
calculation, and some functional brain imaging studies have shown
that calculation is associated with activation of a network of
left-hemisphere language regions, such as the angular gyrus and
the banks of the intraparietal sulcus. We investigate the integrity
of mathematical calculations in three men with large left-hemisphere
perisylvian lesions. Despite severe grammatical impairment
and some difficulty in processing phonological and orthographic
number words, all basic computational procedures were intact
across patients. All three patients solved mathematical problems
involving recursiveness and structure-dependent operations (for
example, in generating solutions to bracket equations). To our
knowledge, these results demonstrate for the first time the remarkable
independence of mathematical calculations from language
grammar in the mature cognitive system
EChOSim: The Exoplanet Characterisation Observatory software simulator
EChOSim is the end-to-end time-domain simulator of the Exoplanet
Characterisation Observatory (EChO) space mission. EChOSim has been developed
to assess the capability EChO has to detect and characterize the atmospheres of
transiting exoplanets, and through this revolutionize the knowledge we have of
the Milky Way and of our place in the Galaxy. Here we discuss the details of
the EChOSim implementation and describe the models used to represent the
instrument and to simulate the detection. Software simulators have assumed a
central role in the design of new instrumentation and in assessing the level of
systematics affecting the measurements of existing experiments. Thanks to its
high modularity, EChOSim can simulate basic aspects of several existing and
proposed spectrometers for exoplanet transits, including instruments on the
Hubble Space Telescope and Spitzer, or ground-based and balloon borne
experiments. A discussion of different uses of EChOSim is given, including
examples of simulations performed to assess the EChO mission
The relationship between radiation-induced G1arrest and chromosome aberrations in Li-Fraumeni fibroblasts with or without germline TP53 mutations
We previously showed that cultured fibroblasts from patients with the cancer-prone Li-Fraumeni (LF) syndrome, having heterozygous germline TP53 mutations, sustain less ionizing radiation-induced permanent G1 arrest than normal fibroblasts. In contrast, fibroblast strains from LF patients without TP53 mutations showed normal G1 arrest. We have now investigated the relationship between the extent of G1 arrest and the level of structural chromosome damage (mainly dicentrics, rings and acentric fragments) in cells at their first mitosis after G1 irradiation, in 9 LF strains with TP53 mutations, 6 without TP53 mutations and 7 normal strains. Average levels of damage in the mutant strains were 50% higher than in normals, whereas in non-mutant LF strains they were 100% higher. DNA double strand breaks (dsb) are known to act as a signal for p53-dependent G1 arrest and to be the lesions from which chromosome aberrations arise. These results suggest that a minimal level of dsb is required before the signal for arrest is activated and that p53-defective cells have a higher signal threshold than p53-proficient cells. Dsb that do not cause G1 blockage can progress to mitosis and appear as simple deletions or interact to form exchange aberrations. The elevated levels in the non-mutant strains may arise from defects in the extent or accuracy of dsb repair. In LF cells with or without TP53 mutations, the reduced capacity to eliminate or repair chromosomal damage of the type induced by ionising radiation, may contribute to cancer predisposition in this syndrome. © 2001 Cancer Research Campaign http://www.bjcancer.co
Highly consistent genetic alterations in childhood adrenocortical tumours detected by comparative genomic hybridization
We have examined 11 cases of childhood adrenocortical tumours for copy number changes using comparative genomic hybridization (CGH). The changes seen are highly consistent between cases, and are independent of tumour type (carcinoma versus adenoma) or the presence of a germline TP53 mutation. The regions of chromosomal gain and loss identified in this study indicate the location of genes that are potentially important in the development and progression of childhood adrenocortical tumours. Finally, the copy number changes identified in childhood tumours are distinctly different to those seen in adult cases (Kjellman et al (1996) Cancer Res56: 4219–4223), and we propose that this indicates that childhood tumours are of embryonal origin. © 1999 Cancer Research Campaig
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