131 research outputs found
Energy consumption comparison of parallel linear systems solver algorithms on HPC infrastructure
Orbit determination of space debris using a bi-static radar configuration with a multiple-beam receiver
A project for polarimetric observations in single dish with Medicina and Noto 32 m antennas
A project with multidisciplinary characteristics, aimed to implement the possibility of polarimetric measurements in single dish at the VLBI stations of Medicina and Noto, is presented. The project will open a new window on many
astrophysical items that may be approached using the already existing instrumentation and facilities of the two Italian radioastronomical stations. We report here some scientific backgrounds, together with some technical evaluations, on which the feasibility of the project is based
The First Very Long Baseline Interferometric SETI Experiment
The first Search for Extra-Terrestrial Intelligence (SETI) conducted with
Very Long Baseline Interferometry (VLBI) is presented. By consideration of the
basic principles of interferometry, we show that VLBI is efficient at
discriminating between SETI signals and human generated radio frequency
interference (RFI). The target for this study was the star Gliese 581, thought
to have two planets within its habitable zone. On 2007 June 19, Gliese 581 was
observed for 8 hours at 1230-1544 with the Australian Long Baseline Array. The
dataset was searched for signals appearing on all interferometer baselines
above five times the noise limit. A total of 222 potential SETI signals were
detected and by using automated data analysis techniques, were ruled out as
originating from the Gliese 581 system. From our results we place an upper
limit of 7 MW/Hz on the power output of any isotropic emitter located in the
Gliese 581 system, within this frequency range. This study shows that VLBI is
ideal for targeted SETI, including follow-up observations. The techniques
presented are equally applicable to next-generation interferometers, such as
the long baselines of the Square Kilometre Array (SKA).Comment: 34 pages, 6 figures, 2 tables. Accepted on 25/05/2012 for publication
in The Astronomical Journa
Shared epigenetic alterations between oral cancer and periodontitis: A preliminary study
Introduction: We recently developed a non-invasive sampling procedure for oral squamous cell carcinoma (OSCC) detection based on DNA methylation analysis of a panel of 13 genes. Oral cancer, as well as acute and chronic inflammatory diseases, may influence the methylation level of several genes in the oral cavity. In the present study, we evaluated the presence of periodontal disease (PD) and the methylation status using our 13-gene panel. Methods: Oral brushing specimens were collected from three different patient groups: 23 gingival OSCC patients, 15 patients affected by PD, and 15 healthy volunteers lacking evidence of PD. DNA methylation analysis was performed and each sample was determined to be positive or negative based on a predefined cut-off value. Results: Positive results were found for 23/23 OSCC patients, 3/15 PD patients, and 0/15 samples from healthy volunteers. The GP1BB and MIR193 genes in the PD group exhibited mean methylation levels similar to OSCC patients. ZAP70 showed different methylation levels among three groups. Conclusion: Preliminary data identified shared epigenetic alterations between PD and OSCC patients in two inflammatory genes (GP1BB and MIR193). This study may help to identify potential links between the two diseases and serve as a starting point for the future research focused on pathogenesis
Pre-operative evaluation of dna methylation profile in oral squamous cell carcinoma can predict tumor aggressive potential
Background: Prognosis of oral squamous cell carcinoma (OSCC) is difficult to exactly assess on pre-operative biopsies. Since OSCC DNA methylation profile has proved to be a useful pre-operative diagnostic tool, the aim of the present study was to evaluate the prognostic impact of DNA methylation profile to discriminate OSCC with high and low aggressive potential. Methods: 36 OSCC cases underwent neoplastic cells collection by gentle brushing of the lesion, before performing a pre-operative biopsy. The CpG islands methylation status of 13 gene (ZAP70, ITGA4, KIF1A, PARP15, EPHX3, NTM, LRRTM1, FLI1, MiR193, LINC00599, MiR296, TERT, GP1BB) was studied by bisulfite Next Generation Sequencing (NGS). A Cox proportional hazards model via likelihood-based component-wise boosting was used to evaluate the prognostic power of the CpG sites. Results: The boosting estimation identified five CpGs with prognostic significance: EPHX3-24, EPHX3-26, ITGA4-3, ITGA4-4, and MiR193-3. The combination of significant CpGs provided promising results for adverse events prediction (Brier score = 0.080, C-index = 0.802 and AUC = 0.850). ITGA4 had a strong prognostic power in patients with early OSCC. Conclusions: These data confirm that the study of methylation profile provides new insights into the molecular mechanisms of OSCC and can allow a better OSCC prognostic stratification even before surgery
A new chemical formulation for control of dental unit water line contamination: An 'in vitro' and clinical 'study'
BACKGROUND: Water delivered by dental units during routine dental practice is highly contaminated. The aim of this study is to evaluate the efficacy of a new chemical solution flushed through Dental Unit Water Lines (DUWL) for the control of contamination inside dental units. MATERIALS AND METHODS: Six old dental units equipped with a device designed to automatically flush disinfecting solutions through the water system (Castellini Autosteril) were selected. Water samples from DUWL effluents were collected in each dental unit for 10 randomly selected days, before and after a 5 minute DUWL disinfecting cycle with TetraAcetylEthileneDiamine (TAED) and persalt (Ster4spray produced by Farmec spa, and distributed by Castellini spa). Water samples were plated in R2A Agar and cultured at room temperature for 7 days, and the total number of heterotrophic microorganisms counted and expressed in Log(10) CFU/mL A general linear model was fitted and multiple regression ANOVA for repeated measures was used for the statistical analysis. RESULTS: The mean contamination in DUWL effluent at baseline was 5.45 ± 0.35 CFU/mL (range 4.79 to 5.93 CFU/mL). When water samples were tested "in vitro" against the chemical, no growth of heterotrophic bacteria was detected after a 5 minute contact in any of the water samples tested. After undergoing a 5 minute disinfecting cycle with the chemical, DUWL mean contamination in water effluents was 2.01 ± 0.32 CFU/mL (range 1.30 to 2.74 CFU/mL) (significant difference with respect to baseline). CONCLUSIONS: An inbetween patient disinfecting procedure consisting of flushing DUWL with TAED and persalt equivalent to 0.26% peracetic acid could be useful in routine dental practice for cross-contamination control
Electromagnetic Design of Broadband Antenna Feed Systems for the Northern Cross Radio Telescope
This contribution deals with the design and implementation of broadband antenna feed systems for the cylindrical offset parabolic reflector of the Northern Cross radio telescope, in the framework of the Square Kilometer Array Design Study (SKADS-FP6) project. Such feed systems have to maintain a proper radiation pattern as well as a good matching condition in the operative frequency band (120-430 MHz) in order to efficiently feed the main reflector. This task is not trivial since more than octave bandwidths are required. Several feed system designs have been carried out on the basis of different architectures such as log periodic antenna arrays, linear arrays of fat dipoles and branched Vivaldi (tapered slot) radiators inside a wired subreflector. Each configuration provides a different trade-off between electrical performance and manufacturing complexity. The most significant computed and experimental results are discussed. Some of the proposed configurations have already been mounted on the Northern Cross Radio Telescope. The adopted mechanical and electronic solutions such as wiring, canalization, amplifier housing and protection are reported. A preliminary study on the application of Focal Plane Arrays on the E/W Arm is also discussed
Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes
In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications
Anxiety and depression in keratotic oral lichen planus: a multicentric study from the SIPMO
Objectives: Oral lichen planus with exclusive keratotic reticular, papular, and/or plaque-like lesions (K-OLP) is a clinical pattern of OLP that may be associated with a complex symptomatology and psychological alteration. The aim of the study was to evaluate the prevalence of anxiety (A) and depression (D) in patients with K-OLP, analyzing the potential predictors which can affect mental health status.
Methods: Three hundred K-OLP patients versus 300 healthy controls (HC) were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), and Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A) were administered.
Results: The K-OLP patients showed statistically higher scores in the NRS, T-PRI, HAM-D, and HAM-A compared with the HC (p-value < 0.001**). A and D were found in 158 (52.7%) and 148 (49.3%) K-OLP patients. Strong linear correlations were identified between HAM-A, HAM-D, NRS, T-PRI, and employment status and between HAM-D, HAM-A, NRS, T-PRI, employment status, and female gender. Multivariate logistic regression revealed that HAM-D and HAM-A showed the greatest increase in the R2 value for A and D in the K-OLP patients, respectively (DR2 = 55.5% p-value < 0.001**; DR2 = 56.5% p-value < 0.001**).
Conclusions: The prevalence of A and D is higher in the K-OLP patients compared with the HC, also found in K-OLP subjects without pain, suggesting that the processing of pain may be in a certain way independent of the processing of mood.
Clinical relevance: Mood disorders and pain assessment should be carefully performed in relation to K-OLP to obtain a complete analysis of the patients
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