2,374 research outputs found
3D Path planning using a fuzzy logic navigational map for Planetary Surface Rovers
This work proposes an innovative app
navigation path-planning problem
exploration rovers by including terrain characteristics.
The objective is to enhance the typical 2D arithmetical
cost function by adding 3D information computed from
the laser-scanned terrain such as terrain height, slopes,
shadows, orientation and terrain roughness.
This paper describes the algorithm developed by UPM
and GMV and the tests made at the GMV outdoor test
facilities using the Moon-Hound rover. This rover is a
50 Kg rover including a Sick laser mounted on a
pan&tilt unit for generation of 3D Digital Elevation
Models (DEM’s). Experimental results have shown the
effectiveness of the proposed approach
Negative immunodiffusion test results obtained with sera of paracoccidioidomycosis patients may be related to low-avidity immunoglobulin G2 antibodies directed against carbohydrate epitopes
Immunodiffusion (ID) is the serologic test most frequently used for the diagnosis and posttherapy follow-up of patients with paracoccidioidomycosis (PCM). the ID test is highly specific (100%), but its sensitivity is relatively low (90%), leading to false-negative results. the aim of this study was to determine the profiles of antibodies in sera from patients with proven PCM and with negative results in the ID test (IDneg) versus positive results in the ID test (IDpos). We analyzed 46 sera from patients with active PCM for total immunoglobulin G (IgG) and IgG subclass responses to Paracoccidioides brasiliensis gp43 antigen (treated or not treated with sodium metaperiodate) by enzyme-linked immunosorbent assay and immunoblotting. Immunoblotting showed that both IDneg and IDpos sera recognized predominantly the gp43 fraction of the P. brasiliensis antigen used in the ID test. IDneg sera contain low-avidity antibodies, low levels of specific IgG (total) and IgGI, and high levels of IgG2 compared with IDpos sera. the antibodies present in IDpos sera were predominantly directed against carbohydrate epitopes, since treatment with sodium metaperiodate resulted in a significant decrease in antibody reactivity. These data suggest that the lack of reactivity of sera from PCM patients in the ID test may be related to the production of low-avidity IgG2 antibodies directed against carbohydrate epitopes.UNICAMP, Fac Med Sci, Dept Clin Pathol, BR-13083970 Campinas, SP, BrazilUNIFESP, Discipline Cellular Biol, São Paulo, SP, BrazilUNIFESP, Discipline Cellular Biol, São Paulo, SP, BrazilWeb of Scienc
The Kinetic Interpretation of the DGLAP Equation, its Kramers-Moyal Expansion and Positivity of Helicity Distributions
According to a rederivation - due to Collins and Qiu - the DGLAP equation can
be reinterpreted (in leading order) in a probabilistic way. This form of the
equation has been used indirectly to prove the bound
between polarized and unpolarized distributions, or positivity of the helicity
distributions, for any . We reanalize this issue by performing a detailed
numerical study of the positivity bounds of the helicity distributions. To
obtain the numerical solution we implement an x-space based algorithm for
polarized and unpolarized distributions to next-to-leading order in ,
which we illustrate. We also elaborate on some of the formal properties of the
Collins-Qiu form and comment on the underlying regularization, introduce a
Kramers-Moyal expansion of the equation and briefly analize its Fokker-Planck
approximation. These follow quite naturally once the master version is given.
We illustrate this expansion both for the valence quark distribution and
for the transverse spin distribution .Comment: 38 pages, 27 figures, Dedicated to Prof. Pierre Ramond for his 60th
birthda
Wireless sensor web for rover planetary exploration
Together with the “traditional“ approach, during the last years a new concept of planetary surface exploration has been introduced and investigated by the space community, including the European Space Agency (ESA). The concept consists in deploying a number of sensors communicating among themselves in a wireless networked architecture (WSN). These sensors, altogether, constitute a distributed instrument with the potential of broadening the capabilities of making science on and around a planetary body. When compared to big and monolithic planetary probes, with payloads able to obtain high-quality local measurements (e.g. by imaging or sampling), wireless sensor networks allow mapping larger planetary surfaces and/or volumes over a large time span. This concept is particularly suitable to retrieve localised simple measurements such as pressure, temperature, humidity or gas type, which could support the major interests of space exploration: 1) determine if life ever arose on a certain celestial body, 2) characterise the geology and topology of the body surface, 3) characterise its climate, and 4) prepare for human exploration. In line with this trend ESA initiated the RF-WIPE project (RF Wireless for Planetary Exploration), with GMV leading a consortium completed by SUPSI (University of Applied Sciences and Arts of Southern Switzerland) and UPM (Technical University of Madrid
Modelling wind-driven rain on buildings in urbanized area using 3-D GIS and LiDAR datasets
This study investigated the distribution of the fraction of rainfall intercepted by the facades of buildings located in an urbanized area. We used the frequently used semi-empirical standard ISO-15927-3 to simulate Wind-Driven Rain on facades. The implementation of the Norm on a neighbourhood scale required a list of parameters, including building geometry and terrain characteristics. For the first time, we proposed the use of combined 3-D GIS and LiDAR data to retrieve all the information necessary to apply the Norm on a large set of buildings. The proposed methodology was tested on a dense urban area of 242 buildings with a wide range of original features. The distributions of simulated catch ratios per facade were exponentially distributed between 0 and 9%. Results obtained were smaller than those usually identified in the literature. This was in large part explained by two points: (i) the buildings considered are located in a dense urban area where surrounding buildings create an obstruction factor that limits WDR on facades and, (ii) not only are windward facades considered, but also facades located in the dominant wind direction which received almost no rain. Facade orientation is a clear factor that influenced the amount of rainfall in contact with it. Modern GIS techniques are sufficiently advanced to provide the necessary information to assess WDR. However, the accuracy of our conclusion was limited by the inherent simplicity of the Norm, which has potential for improvement in terms of the definition of the obstruction factor and the range of building geometry which it takes into consideration. (c) 2012 Elsevier Ltd. All rights reserved
Determination of the 12C nuclear density through heavy-ion elastic scattering experiments
Precise elastic scattering differential cross sections have been measured for the 12C158Ni,208Pb systems at
sub-barrier energies. The corresponding bare potentials have been determined at interaction distances larger
than the respective barrier radii, and the results have been compared with those from an early extensive
systematics for the nuclear potential. The present data have been combined with others for the 12C
112C,208Pb systems at intermediate energies, in order to extract the 12C ground-state nuclear density through
an unfolding method
The mechanical and EM simulations of the CryoAC for the ATHENA X-IFU
The design phase of the CryoAC DM for the ATHENA X-IFU has concerned numerical simulations to exploit different fabrication possibilities. The mechanical simulations have accounted for the peculiar detector structure: 4 silicon chips asymmetrically suspended by means of 4 microbridges each. A preliminary study was performed to analyze the response to acceleration spectra in the frequency domain, shocks and time domain random displacement, prior to a real vibration test campaign. EM simulations to spot unwanted magnetic fields have been conducted as well. In this work we will show the latest advance in the design of the new detectors, showing the main results coming from various simulations
Cost-effectiveness of a hypertension management programme in an elderly population: a Markov model
<p>Abstract</p> <p>Background</p> <p>Mounting evidence shows that multi-intervention programmes for hypertension treatment are more effective than an isolated pharmacological strategy. Full economic evaluations of hypertension management programmes are scarce and contain methodological limitations. The aim of the study was to evaluate if a hypertension management programme for elderly patients is cost-effective compared to usual care from the perspective of a third-party payer.</p> <p>Methods</p> <p>We built a cost-effectiveness model using published evidence of effectiveness of a comprehensive hypertension programme vs. usual care for patients 65 years or older at a community hospital in Buenos Aires, Argentina. We explored incremental cost-effectiveness between groups. The model used a life-time framework adopting a third-party payer's perspective. Incremental cost-effectiveness ratio (ICER) was calculated in International Dollars per life-year gained. We performed a probabilistic sensitivity analysis (PSA) to explore variable uncertainty.</p> <p>Results</p> <p>The ICER for the base-case of the "Hypertension Programme" versus the "Usual care" approach was 1,124 International Dollars per life-year gained. PSA did not significantly influence results. The programme had a probability of 43% of being dominant (more effective and less costly) and, overall, 95% chance of being cost-effective.</p> <p>Discussion</p> <p>Results showed that "Hypertension Programme" had high probabilities of being cost-effective under a wide range of scenarios. This is the first sound cost-effectiveness study to assess a comprehensive hypertension programme versus usual care. This study measures hard outcomes and explores robustness through a probabilistic sensitivity analysis.</p> <p>Conclusions</p> <p>The comprehensive hypertension programme had high probabilities of being cost-effective versus usual care. This study supports the idea that similar programmes could be the preferred strategy in countries and within health care systems where hypertension treatment for elderly patients is a standard practice.</p
The PLASMONX Project for advanced beam physics experiments
The Project PLASMONX is well progressing into its
design phase and has entered as well its second phase of
procurements for main components. The project foresees
the installation at LNF of a Ti:Sa laser system (peak
power > 170 TW), synchronized to the high brightness
electron beam produced by the SPARC photo-injector.
The advancement of the procurement of such a laser
system is reported, as well as the construction plans of a
new building at LNF to host a dedicated laboratory for
high intensity photon beam experiments (High Intensity
Laser Laboratory). Several experiments are foreseen
using this complex facility, mainly in the high gradient
plasma acceleration field and in the field of mono-
chromatic ultra-fast X-ray pulse generation via Thomson
back-scattering. Detailed numerical simulations have
been carried out to study the generation of tightly focused
electron bunches to collide with laser pulses in the
Thomson source: results on the emitted spectra of X-rays
are presented
The predictive and prognostic potential of plasma telomerase reverse transcriptase (TERT) RNA in rectal cancer patients
Background: Preoperative chemoradiotherapy (CRT) followed by surgery is the standard care for locally advanced rectal cancer,
but tumour response to CRT and disease outcome are variable. The current study aimed to investigate the effectiveness of plasma
telomerase reverse transcriptase (TERT) levels in predicting tumour response and clinical outcome.
Methods: 176 rectal cancer patients were included. Plasma samples were collected at baseline (before CRT\ubcT0), 2 weeks after
CRT was initiated (T1), post-CRT and before surgery (T2), and 4\u20138 months after surgery (T3) time points. Plasma TERT mRNA levels
and total cell-free RNA were determined using real-time PCR.
Results: Plasma levels of TERT were significantly lower at T2 (Po0.0001) in responders than in non-responders. Post-CRT TERT
levels and the differences between pre- and post-CRT TERT levels independently predicted tumour response, and the prediction
model had an area under curve of 0.80 (95% confidence interval (CI) 0.73\u20130.87). Multiple analysis demonstrated that patients with
detectable TERT levels at T2 and T3 time points had a risk of disease progression 2.13 (95% CI 1.10\u20134.11)-fold and 4.55 (95% CI
1.48\u201313.95)-fold higher, respectively, than those with undetectable plasma TERT levels.
Conclusions: Plasma TERT levels are independent markers of tumour response and are prognostic of disease progression in rectal
cancer patients who undergo neoadjuvant therapy
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