2,437 research outputs found
Performance comparison between signal digitizers and low-cost digital oscilloscopes: spectroscopic, pulse shape discrimination and timing capabilities for nuclear detectors
Signal digitizers revolutionized the approach to the electronics readout of
radiation detectors in Nuclear Physics. These highly specialized pieces of
equipment are designed to acquire the signals that are characteristic of the
detectors in nuclear physics experiments. The functions of the several modules
that were once needed for signal acquisition, can now be substituted by a
single digitizer. As suggested by the name, with such readout modules, signals
are first digitized (i.e. the signal waveform is sampled and converted to a
digital representation) and then either stored or analyzed on-the-fly. The
performances can be comparable or better than the traditional analog
counterparts, in terms of energy, time resolution, and acquisition rate.
In this work, we investigate the use of general-purpose digital oscilloscopes
as signal digitizers for nuclear detectors. In order to have a proper
comparison, we employ a distributed data acquisition system (DAQ), that
standardizes the interface between the hardware and the on-line data analysis.
The signals, from a set of typical radiation detectors, are digitized and
analyzed with the very same algorithms in order to avoid biases due to
different software analysis. We compare two traditional signal digitizers (CAEN
DT5725 and CAEN DT5751) to two low-cost digital oscilloscopes (Digilent Analog
Discovery 2, and Red Pitaya STEMLab 125-14), in terms of their capabilities for
spectroscopy (energy resolution), time resolution, pulse shape discrimination,
and maximum acquisition rate.Comment: 17 pages, 8 figures, 4 tables, Prepared for submission to JINS
Evaluation of a duplex real-time PCR in human serum for simultaneous detection and differentiation of Schistosoma mansoni and Schistosoma haematobium infections - a cross-sectional study
BACKGROUND: We evaluated a one-tube multiplex real-time PCR targeting DNA of Schistosoma haematobium complex and S. mansoni complex in serum samples obtained at different German diagnostic centers. METHODS: Simplex real-time PCR protocols for the detection of the multi-copy DNA-repeats Dra1 of S. haematobium complex and Sm1-7 of S. mansoni complex in serum were combined to a new one-tube multiplex format. The new PCR was subjected to full validation including evaluation in a diagnostic real-life setting with travelers and migrants. PCR results were compared with those of stool and urine microscopy, serology, and circulating cathodic antigen (CCA) rapid diagnostic tests in urine. Sensitivity and specificity of the diagnostic approaches were analyzed using latent class analysis (LCA). RESULTS: LCA assessment indicated sensitivity and specificity of 94.9% and 98.4%, respectively, for serum PCR if serology was included in the calculation, and 100% and 95.6%, respectively, if serology was not included as a parameter not necessarily associated with active infection. Agreement between the compared diagnostic procedures at genus level was fair (kappa 0.273) if serology was included and moderate (kappa 0.420) if serology was not included. DISCUSSION: The PCR assay proved to be highly reliable for the diagnosis of schistosomiasis in travelers and migrants
a distributed data acquisition system for nuclear detectors
Nowadays, many examples of data acquisition (DAQ) software for experimental nuclear physics are monolithic processes that run on a computer attached to the DAQ hardware. In this article we present a distributed DAQ system developed for the C-BORD project. With our system, we propose a novel approach, in which each task related to the different DAQ parts (acquisition, pre-process, analysis, etc.) runs in a separate process. In particular, the system is composed of a set of servers that exchange information through dedicated communication sockets. Therefore, with this architecture, an important advantage is the possibility to run the processes on different computers to distribute the computational load. The initial tests of the system have been giving excellent results, both in terms of performance (i.e., maximum acquisition rates) and stability. The project entitled "Effective container inspection at BORDer control points" (C-BORD) is funded by the European H2020 programme. Its aim is to develop a comprehensive set of technologies for the generalized non-intrusive inspection (NII) of containers and large-volume freight at the European Union border
Two friends with eroded nodules on the ears : Atypical fibroxanthoma case report
Atypical fibroxanthoma is an uncommon mesenchymal tumor that manifests clinically as a reddish papule or nodule in sun-exposed areas of the body. The clinical presentation is not specific and histology and immunohistochemistry are both necessary for a correct diagnosis. Surgery is the gold standard of therapy. Recurrence and metastasis should be excluded with a follow-up at 6 months, since this tumor should nowadays be considered a medium-grade neoplasm, rather than low-grade as previously believed. We report the case of two friends who came to our hospital during the same period, complaining of very similar lesions. After biopsy and immunohistochemical examination, a diagnosis of atypical fibroxanthoma in both cases was formulated
Evaluation of a duplex real-time PCR in human serum for simultaneous detection and differentiation of Schistosoma mansoni and Schistosoma haematobium infections - cross-sectional study
Background: We evaluated a one-tube multiplex real-time PCR targeting DNA of Schistosoma haematobium
complex and S. mansoni complex in serum samples obtained at different German diagnostic centers.
Methods: Simplex real-time PCR protocols for the detection of the multi-copy DNA-repeats Dra1 of
S. haematobium complex and Sm1-7 of S. mansoni complex in serum were combined to a new one-tube multiplex
format. The new PCR was subjected to full validation including evaluation in a diagnostic real-life setting with
travelers and migrants. PCR results were compared with those of stool and urine microscopy, serology, and
circulating cathodic antigen (CCA) rapid diagnostic tests in urine. Sensitivity and specificity of the diagnostic
approaches were analyzed using latent class analysis (LCA).
Results: LCA assessment indicated sensitivity and specificity of 94.9% and 98.4%, respectively, for serum PCR if
serology was included in the calculation, and 100% and 95.6%, respectively, if serology was not included as a
parameter not necessarily associated with active infection. Agreement between the compared diagnostic procedures at genus level was fair (kappa 0.273) if serology was included and moderate (kappa 0.420) if serology
was not included.
Discussion: The PCR assay proved to be highly reliable for the diagnosis of schistosomiasis in travelers and
migrants
Families of twisted tensor product codes
Using geometric properties of the variety \cV_{r,t}, the image under the
Grassmannian map of a Desarguesian -spread of \PG(rt-1,q), we
introduce error correcting codes related to the twisted tensor product
construction, producing several families of constacyclic codes. We exactly
determine the parameters of these codes and characterise the words of minimum
weight.Comment: Keywords: Segre Product, Veronesean, Grassmannian, Desarguesian
spread, Subgeometry, Twisted Product, Constacyclic error correcting code,
Minimum weigh
Laboratory Tests of Low Density Astrophysical Equations of State
Clustering in low density nuclear matter has been investigated using the
NIMROD multi-detector at Texas A&M University. Thermal coalescence modes were
employed to extract densities, , and temperatures, , for evolving
systems formed in collisions of 47 MeV Ar + Sn,Sn
and Zn + Sn, Sn. The yields of , , He, and
He have been determined at = 0.002 to 0.032 nucleons/fm and
= 5 to 10 MeV. The experimentally derived equilibrium constants for
particle production are compared with those predicted by a number of
astrophysical equations of state. The data provide important new constraints on
the model calculations.Comment: 5 pages, 3 figure
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