66 research outputs found
Characterization of a Be(p,xn) neutron source for fission yields measurements
We report on measurements performed at The Svedberg Laboratory (TSL) to
characterize a proton-neutron converter for independent fission yield studies
at the IGISOL-JYFLTRAP facility (Jyv\"askyl\"a, Finland). A 30 MeV proton beam
impinged on a 5 mm water-cooled Beryllium target. Two independent experimental
techniques have been used to measure the neutron spectrum: a Time of Flight
(TOF) system used to estimate the high-energy contribution, and a Bonner Sphere
Spectrometer able to provide precise results from thermal energies up to 20
MeV. An overlap between the energy regions covered by the two systems will
permit a cross-check of the results from the different techniques. In this
paper, the measurement and analysis techniques will be presented together with
some preliminary results.Comment: 3 pages, 3 figures, also submitted as proceedings of the
International Conference on Nuclear Data for Science and Technology 201
Are Urologists Ready for Interpretation of Multiparametric MRI Findings? A Prospective Multicentric Evaluation
Aim: To assess urologists’ proficiency in the interpretation of multiparametric magnetic resonance imaging (mpMRI). Materials and Methods: Twelve mpMRIs were shown to 73 urologists from seven Italian institutions. Responders were asked to identify the site of the suspicious nodule (SN) but not to assign a PIRADS score. We set an a priori cut-off of 75% correct identification of SN as a threshold for proficiency in mpMRI reading. Data were analyzed according to urologists’ hierarchy (UH; resident vs. consultant) and previous experience in fusion prostate biopsies (E-fPB, defined as <125 vs. ≥125). Additionally, we tested for differences between non-proficient vs. proficient mpMRI readers. Multivariable logistic regression analyses (MVLRA) tested potential predictors of proficiency in mpMRI reading. Results: The median (IQR) number of correct identifications was 8 (6–8). Anterior nodules (number 3, 4 and 6) represented the most likely prone to misinterpretation. Overall, 34 (47%) participants achieved the 75% cut-off. When comparing consultants vs. residents, we found no differences in terms of E-fPB (p = 0.9) or in correct identification rates (p = 0.6). We recorded higher identification rates in urologists with E-fBP vs. their no E-fBP counterparts (75% vs. 67%, p = 0.004). At MVLRA, only E- fPB reached the status of independent predictor of proficiency in mpMRI reading (OR: 3.4, 95% CI 1.2–9.9, p = 0.02) after adjusting for UH and type of institution. Conclusions: Despite urologists becoming more familiar with interpretation of mpMRI, their results are still far from proficient. E-fPB enhances the proficiency in mpMRI interpretation
Non-nociceptive roles of opioids in the CNS: opioids' effects on neurogenesis, learning, memory and affect.
Mortality due to opioid use has grown to the point where, for the first time in history, opioid-related deaths exceed those caused by car accidents in many states in the United States. Changes in the prescribing of opioids for pain and the illicit use of fentanyl (and derivatives) have contributed to the current epidemic. Less known is the impact of opioids on hippocampal neurogenesis, the functional manipulation of which may improve the deleterious effects of opioid use. We provide new insights into how the dysregulation of neurogenesis by opioids can modify learning and affect, mood and emotions, processes that have been well accepted to motivate addictive behaviours
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Track A Basic Science
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138319/1/jia218438.pd
Spontaneous parametric down conversion in a doubly resonant one-dimensional photonic crystal
We study spontaneous parametric down conversion (SPDC) in a one-dimensional photonic crystal designed to operate in a doubly resonant configuration, where the frequencies of the pump and the generated photons are both tuned to band-edge resonances. We investigate the spectral correlations of the generated photons as a function of the spectral width of the pump, and demonstrate that the SPDC generation rate can scale with the fifth power of the structure length in the limit of a quasi-continuous-wave pump. We show that such an unusual scaling can be simply connected with the scaling of second-harmonic generation in the same structure, illustrating the general link between spontaneous and stimulated parametric nonlinear processes
Bragg gratings will improve signal-to-noise in ÏâœÂłâŸ degenerate photon-pair generation
Dual-pump photon-pair sources typically suffer from parasitic pair production. To circumvent this, we propose and design a source in which parasitic pairs are suppressed by proper engineering of photonic band gaps in a Bragg grating.2 page(s
A miniaturized alpha spectrometer for the calibration of an avalanche-confinement TEPC
The design and development of a recent avalanche-confinement tissue equivalent proportional counter (TEPC) for microdosimetry and nanodosimetry applications required the selection of a proper miniaturized solid state detector (SSD) for detecting alpha particles emitted by a thick removable Cm-244 source embedded in the cylindrical TEPC chamber for characterization and calibration purposes. Since the available cavity for embedding the SSD detector is only 4.2 mm in diameter, no standard devices can be exploited. The selection of the best SSD for this application was based on the following requirements: very low size, proper energy resolution, cheapness. The performances of the finally selected SSD were assessed by exploiting a multi-peak calibration alpha source (Pu-239, Am-241, Cm-244). The measured energy resolution resulted about 25 keV FWHM. The TEPC calibration procedure, which exploits the selected SSD aligned to the built-in Cm-244 alpha source, is described in details
An operative dengue risk stratification system in Argentina based on geospatial technology
Based on an agreement between the Ministry of Health and the National Space Activities Commission in Argentina, an integrated informatics platform for dengue risk using geospatial technology for the surveillance and prediction of risk areas for dengue fever has been designed. The task was focused on developing stratification based on environmental (historical and current), viral, social and entomological situation for >3,000 cities as part of a system. The platform, developed with open-source software with pattern design, following the European Space Agency standards for space informatics, delivers two products: a national risk map consisting of point vectors for each city/town/locality and an approximate 50 m resolution urban risk map modelling the risk inside selected high-risk cities. The operative system, architecture and tools used in the development are described, including a detailed list of end usersâ requirements. Additionally, an algorithm based on bibliography and landscape epidemiology concepts is presented and discussed. The system, in operation since
September 2011, is capable of continuously improving the algorithms producing improved risk stratifications without a
complete set of inputs. The platform was specifically developed for surveillance of dengue fever as this disease has reemerged in Argentina but the aim is to widen the scope to include also other relevant vector-borne diseases such as chagas, malaria and leishmaniasis as well as other countries belonging to south region of Latin America
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