1,796 research outputs found
On the Use of Generative Adversarial Networks for Aircraft Trajectory Generation and Atypical Approach Detection
International audienceAircraft approach flight path safety management provides procedures that guide the aircraft to intercept the final approach axis and runway slope before landing. In order to detect atypical behavior, this paper explores the use of data generative models to learn real approach flight path probability distributions and identify flights that do not follow these distributions. Through the use of Generative Adversarial Networks (GAN), a GAN is first trained to learn real flight paths, generating new flights from learned distributions. Experiments show that the new generated flights follow realistic patterns. Unlike trajectories generated by physical models, the proposed technique, only based on past flight data, is able to account for external factors such as Air Traffic Control (ATC) orders, pilot behavior or meteorological phenomena. Next, the trained GAN is used to identify abnormal trajectories and compare the results with a clustering technique combined with a functional principal component analysis. The results show that reported non compliant trajectories are relevant
Trajectory APproach AnalysiS: A Post-operational Aircraft Approach Analysis Tool
International audienceIn aviation, safety has always been a key issue to reduce the number of incidents and accidents. Nowadays, it is even more important since the air traffic increases every year, and is predicted to reach 7.8 billion passengers worldwide in 2036. Flight safety offices aim at enhancing safety, analyzing past events, and preventing potential critical occurrences. This paper presents TAPAS, a post-operational aircraft approach analysis tool. The software offers an interactive analysis of aircraft approach energy management. The software uses and validates an existing atypical approach detection algorithm on flight data record and flight safety office events from airlines. Various correlations and analysis are conducted to illustrate the potential benefits of this methodology
Automatización del análisis exploratorio de datos y procesamiento geoquímico univariado empleando Python
Process automation is being implemented in different disciplines of earth sciences, as seen in the implementation of libraries such as Pyrolite, PyGeochemCalc, dh2loop 1.0, NeuralHydrology, GeoPyToo among others. The present work addresses a methodology to automate the geochemical univariate analysis by using Python and open-source packages such as pandas, seaborn, matplotlib, statsmodels which will be integrated into a script in a local work environment such as Jupyter notebook or in an online environment such as Google Collaboratory. The script is designed to process any type of geochemical data, allowing to remove outliers, perform calculations and graphs of the elements and their respective geological domain. The results include graphics such as boxplot, quantile-quantile and calculations of normality tests and geochemical parameters, allowing to determine the background and threshold of the elements worked. The result of the geochemical parameters will be further processed in geographic information software which allows to generate the univariate anomaly map and the anomalous basins.La automatización de procesos viene siendo implementada en distintas disciplinas de las ciencias geológicas, ello se ve en el desarrollo de librerías como Pyrolite, PyGeochemCalc, dh2loop 1.0, NeuralHydrology, GeoPyTools entre otros. El presente trabajo aborda una metodología para automatizar el análisis geoquímico univariado mediante el uso de paquetes de código abierto en Python como Pandas, Seaborn, Matplotlib, Statsmodels y Scipy, las cuales serán integrados a un script en un entorno de trabajo local como Jupyter Notebook o en un entorno online como Google Colaboratory. El Script está diseñado para procesar cualquier tipo de datos geoquímicos, permitiendo remover los outliers, realizar cálculos y gráficos de los elementos con su respectivo dominio geológico. Los resultados incluyen gráficos como el box-plot, cuantil-cuantil, cálculos de las pruebas de normalidad y de los parámetros geoquímicos, lo que permite determinar el valor de fondo o background y el umbral o threshold de los elementos trabajados. El resultado de los parámetros geoquímicos será procesado posteriormente en softwares de información geográfica, la cual permite generar mapas de anomalías metálicas univariadas y de las cuencas anómalas
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV
Results are presented from a search for physics beyond the standard model
based on events with large missing transverse energy, at least three jets, and
at least one, two, or three b-quark jets. The study is performed using a sample
of proton-proton collision data collected at sqrt(s) = 7 TeV with the CMS
detector at the LHC in 2011. The integrated luminosity of the sample is 4.98
inverse femtobarns. The observed number of events is found to be consistent
with the standard model expectation, which is evaluated using control samples
in the data. The results are used to constrain cross sections for the
production of supersymmetric particles decaying to b-quark-enriched final
states in the context of simplified model spectra.Comment: Submitted to Physical Review
Performance and Operation of the CMS Electromagnetic Calorimeter
The operation and general performance of the CMS electromagnetic calorimeter
using cosmic-ray muons are described. These muons were recorded after the
closure of the CMS detector in late 2008. The calorimeter is made of lead
tungstate crystals and the overall status of the 75848 channels corresponding
to the barrel and endcap detectors is reported. The stability of crucial
operational parameters, such as high voltage, temperature and electronic noise,
is summarised and the performance of the light monitoring system is presented
Molecular Biomarker Analyses Using Circulating Tumor Cells
Evaluation of cancer biomarkers from blood could significantly enable biomarker assessment by providing a relatively non-invasive source of representative tumor material. Circulating Tumor Cells (CTCs) isolated from blood of metastatic cancer patients hold significant promise in this regard.Using spiked tumor-cells we evaluated CTC capture on different CTC technology platforms, including CellSearch and two biochip platforms, and used the isolated CTCs to develop and optimize assays for molecular characterization of CTCs. We report similar performance for the various platforms tested in capturing CTCs, and find that capture efficiency is dependent on the level of EpCAM expression. We demonstrate that captured CTCs are amenable to biomarker analyses such as HER2 status, qRT-PCR for breast cancer subtype markers, KRAS mutation detection, and EGFR staining by immunofluorescence (IF). We quantify cell surface expression of EGFR in metastatic lung cancer patient samples. In addition, we determined HER2 status by IF and FISH in CTCs from metastatic breast cancer patients. In the majority of patients (89%) we found concordance with HER2 status from patient tumor tissue, though in a subset of patients (11%), HER2 status in CTCs differed from that observed in the primary tumor. Surprisingly, we found CTC counts to be higher in ER+ patients in comparison to HER2+ and triple negative patients, which could be explained by low EpCAM expression and a more mesenchymal phenotype of tumors belonging to the basal-like molecular subtype of breast cancer.Our data suggests that molecular characterization from captured CTCs is possible and can potentially provide real-time information on biomarker status. In this regard, CTCs hold significant promise as a source of tumor material to facilitate clinical biomarker evaluation. However, limitations exist from a purely EpCAM based capture system and addition of antibodies to mesenchymal markers could further improve CTC capture efficiency to enable routine biomarker analysis from CTCs
Allosteric Regulation of Fibronectin/α5β1 Interaction by Fibronectin-Binding MSCRAMMs
Citation: Liang, X. W., Garcia, B. L., Visai, L., Prabhakaran, S., Meenan, N. A. G., Potts, J. R., . . . Hook, M. (2016). Allosteric Regulation of Fibronectin/alpha(5)beta(1) Interaction by Fibronectin-Binding MSCRAMMs. Plos One, 11(7), 17. doi:10.1371/journal.pone.0159118Adherence ofmicrobes to host tissues is a hallmark of infectious disease and is often mediated by a class of adhesins termed MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules). Numerous pathogens express MSCRAMMs that specifically bind the heterodimeric human glycoprotein fibronectin (Fn). In addition to roles in adhesion, Fn-binding MSCRAMMs exploit physiological Fn functions. For example, several pathogens can invade host cells by a mechanism whereby MSCRAMM-bound Fn bridges interaction with alpha(5)beta(1) integrin. Here, we investigate two Fn-binding MSCRAMMs, FnBPA (Staphylococcus aureus) and BBK32 (Borrelia burgdorferi) to probe structure-activity relationships of MSCRAMM-induced Fn/alpha(5)beta(1) integrin activation. Circular dichroism, fluorescence resonance energy transfer, and dynamic light scattering techniques uncover a conformational rearrangement of Fn involving domains distant from the MSCRAMM binding site. Surface plasmon resonance experiments demonstrate a significant enhancement of Fn/alpha(5)beta(1) integrin affinity in the presence of FnBPA or BBK32. Detailed kinetic analysis of these interactions reveal that this change in affinity can be attributed solely to an increase in the initial Fn/alpha(5)beta(1) on-rate and that this rate-enhancement is dependent on high-affinity Fn-binding by MSCRAMMs. These data implicate MSCRAMM-induced perturbation of specific intramolecular contacts within the Fn heterodimer resulting in activation by exposing previously cryptic alpha(5)beta(1) interaction motifs. By correlating structural changes in Fn to a direct measurement of increased Fn/alpha(5)beta(1) affinity, this work significantly advances our understanding of the structural basis for the modulation of integrin function by Fn-binding MSCRAMMs
Group 2 ITI Consensus Report: Prosthodontics and implant dentistry
ObjectivesWorking Group 2 was convened to address topics relevant to prosthodontics and dental implants. Systematic reviews were developed according to focused questions addressing (a) the number of implants required to support fixed full‐arch restorations, (b) the influence of intentionally tilted implants compared to axial positioned implants when supporting fixed dental prostheses (FDPs), (c) implant placement and loading protocols, (d) zirconia dental implants, (e) zirconia and metal ceramic implant supported single crowns and (f) zirconia and metal ceramic implant supported FDPs.Materials and methodsGroup 2 considered and discussed information gathered in six systematic reviews. Group participants discussed statements developed by the authors and developed consensus. The group developed and found consensus for clinical recommendations based on both the statements and the experience of the group. The consensus statements and clinical recommendations were presented to the plenary (gathering of all conference attendees) and discussed. Final versions were developed after consensus was reached.ResultsA total of 27 consensus statements were developed from the systematic reviews. Additionally, the group developed 24 clinical recommendations based on the combined expertise of the participants and the developed consensus statements.ConclusionsThe literature supports the use of various implant numbers to support full‐arch fixed prostheses. The use of intentionally tilted dental implants is indicated when appropriate conditions exist. Implant placement and loading protocols should be considered together when planning and treating patients. One‐piece zirconia dental implants can be recommended when appropriate clinical conditions exist although two‐piece zirconia implants should be used with caution as a result of insufficient data. Clinical performance of zirconia and metal ceramic single implant supported crowns is similar and each demonstrates significant, though different, complications. Zirconia ceramic FDPs are less reliable than metal ceramic. Implant supported monolithic zirconia prostheses may be a future option with more supporting evidence.</p
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