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A Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique and Three Types of Gamma-ray Detectors
No full textA Feasibility Study to Determine Cooling Time and Burnup of ATR Fuel Using a Nondestructive Technique1 Rahmat Aryaeinejad, Jorge Navarro, and David W Nigg Idaho National Laboratory Abstract Effective and efficient Advanced Test Reactor (ATR) fuel management require state of the art core modeling tools. These new tools will need isotopic and burnup validation data before they are put into production. To create isotopic, burn up validation libraries and to determine the setup for permanent fuel scanner system a feasibility study was perform. The study consisted in measuring short and long cooling time fuel elements at the ATR canal. Three gamma spectroscopy detectors (HPGe, LaBr3, and HPXe) and two system configurations (above and under water) were used in the feasibility study. The first stage of the study was to investigate which detector and system configuration would be better suited for different scenarios. The second stage of the feasibility study was to create burnup and cooling time calibrations using experimental isotopic data collected and ORIGEN 2.2 burnup data. The results of the study establish that a better spectra resolution is achieve with an above the water configuration and that three detectors can be used in the permanent fuel scanner system for different situations. In addition it was conclude that a number of isotopic ratios and absolute measurements could be used to predict ATR fuel burnup and cooling times. 1This work was supported by the U.S. Depart¬ment of Energy (DOE) under Battelle Energy Alliance, LLC Contract No. DE-AC07-05ID14517
Physical Neutron Dosimetry for the University of Pavia Thermal Neutron Source for BNCT Radiobiological Research
No full textThe Idaho National Laboratory and the University of Pavia are collaborating in the field of medical neutron dosimetry specific to Neutron Capture Therapy (NCT) applications. This effort resides within a larger framework of computational and experimental dosimetric intercomparisons of several thermal neutron sources used for preclinical NCT radiobiology research worldwide. Recognizing the importance of accurate and reproducible physical beam dosimetry as an essential tool for combination of preclinical and clinical results from different facilities, we have conducted an experimental characterization of the neutronic performance of the thermal neutron source at the University of Pavia TRIGATM research reactor facility. The characterization methodology is based on neutron activation spectrometry coupled with rigorous least-squares-based spectral deconvolution procedures to produce the desired neutron flux, adjusted dosimetry reaction rates, and corresponding radiobiological dosimetric information. Results show that the Pavia neutron source is well thermalized, with a Cadmium Ratio of approximately 80 and a thermal flux of approximately 1 x 1010 n/cm2-s or greater, depending on the specific irradiation location. The submitted poster will discuss further details of the application of advanced modeling and simulation approaches for computational dosimetry of neutron sources, the use of neutron activation spectrometry for experimental validation of research reactor based neutron source performance, and the specific results obtained for the TRIGA facility at Pavia
On the regulation of centriole duplication in human cells : exploring the interactions of polo-like kinase 4 with the centrosomal proteins Cep192 and STIL
No full textCentrioles duplicate once in each cell cycle to give rise to two centrosomes that form the spindle poles during mitosis. Aberrant centriole duplication can result in the formation of supernumerary centrosomes, leading to incorrect spindle assembly and chromosome segregation errors, thereby possibly contributing to carcinogenesis (Ganem et al., 2009; Nigg, 2002; Zyss and Gergely, 2008). Thus, to ensure genome stability, centriole duplication has to be precisely regulated. Polo-like kinase 4 (PLK4) is a key regulator of centriole duplication (Bettencourt-Dias et al., 2005; Habedanck et al., 2005). PLK4 is characterized by an N-terminal Ser/Thr kinase domain and three C-terminal Polo-boxes (PB1-PB3) (Slevin et al., 2012). The PB1-PB2 domain is required for PLK4's centrosomal localization and binding to Cep152 (Cizmecioglu et al., 2010; Hatch et al., 2010; Slevin et al., 2012). In contrast to PB1-PB2, no binding partners have been described for PB3.
Here, we identify Cep192 and STIL as novel interaction partners of PLK4-PB1-PB2 and PLK4-PB3, respectively. In the first part of this study, we reveal that Cep192 directly binds PB1-PB2 via a short region within its N-terminus, which contains conserved patches of acidic residues. We show that also in the case of Cep152 a short N-terminal acidic region is critical for the binding to PB1-PB2. These acidic regions of Cep192 and Cep152 enable electrostatic interactions with positively charged residues of the PB1-PB2 domain in order to promote PLK4 centriolar recruitment (Sonnen et al., 2013). In the second part of this study, we identify STIL as the first known binding partner of PLK4-PB3. We show that the coiled-coil motif of STIL (STIL-CC) is necessary and sufficient for this interaction and thus important for centriole duplication. Based on a collaboration for crystallographic and NMR analyses, we furthermore demonstrate that PB3 adopts a canonical PB fold, and that the PLK4-PB3/STIL-CC binding mimics coiled-coil formation. Analysis of structure-guided STIL mutants suggests a dual binding mode of STIL-CC to PB3 and L1 of PLK4 (linker between the catalytic domain and the PB domains). Taken together, we propose a speculative model for the initial steps of procentriole assembly according to which PLK4 is recruited to centrioles by electrostatic interactions between PB1-PB2 and Cep192/Cep152, and thereafter is stabilized and activated via STIL-CC binding to PB3 and L1
Neutron Spectrometry for the University of Pavia TRIGA Thermal Neutron Source Facility
No full textThe University of Pavia and the Idaho National
Laboratory (INL) are collaborating in the field of
medical neutron dosimetry specific to Neutron
Capture Therapy (NCT) radiobiological research
applications. Recognizing the importance of
accurate and reproducible radiation dosimetry as an
essential tool for interpretation and combination of
preclinical and clinical results from different research
facilities that are active in this field, we have
conducted an experimental characterization of the
neutronic performance of the reactor based thermal
neutron source for nuclear medical research at the
University of Pavia TRIGATM research reactor. This
activity is part of a larger dosimetry intercomparison
exercise, based on a common experimental protocol
that also includes the thermal neutron irradiation
facilities used for medical research at the Missouri
University Research Reactor (MURR) and the RA-3
Research Reactor in Buenos Aires, Argentina
Physical Neutron Dosimetry for the University of Pavia Thermal Neutron Source for BNCT Research
No full textAre language production problems apparent in adults who no longer meet diagnostic criteria for attention-deficit/hyperactivity disorder?
No full textIn this study, we examined sentence production in a sample of adults (N = 21) who had had attention-deficit/hyperactivity disorder (ADHD) as children, but as adults no longer met DSM-IV diagnostic criteria (APA, 2000). This “remitted” group was assessed on a sentence production task. On each trial, participants saw two objects and a verb. Their task was to construct a sentence using the objects as arguments of the verb. Results showed more ungrammatical and disfluent utterances with one particular type of verb (i.e., participle). In a second set of analyses, we compared the remitted group to both control participants and a “persistent” group, who had ADHD as children and as adults. Results showed that remitters were more likely to produce ungrammatical utterances and to make repair disfluencies compared to controls, and they patterned more similarly to ADHD participants. Conclusions focus on language output in remitted ADHD, and the role of executive functions in language production
Interpolated Lake Bathymetry of Lake Lucerne
No full textThis dataset provides the interpolated bathymetry of Lake Lucerne used for the numerical wave propagation simulation performed in the study “Shallow-Water Tsunami Deposits: Evidence from Sediment Cores and Numerical Wave Propagation of the 1601 CE Lake Lucerne” by Nigg et al. (in review). The multibeam echo-sounder bathymetry dataset of Lake Lucerne acquired by Hibe et al. (2011) was resampled from a grid size of 1x1 m to 5x5 m to reduce computational time using ArcMap (version 10.8.1). In addition, large artificial shoreline modifications were cropped and interpolated based on historical maps. Shallow-water areas (water depth 0-4m), which are not entirely covered by the bathymetrical data were linearly interpolated to the shoreline.
The original bathymetry was acquired using a Geo-Acoustics GeoSwath Plus 125 kHz interferometer by Hilbe et al. (2011). Positioning was acquired with a Leica SR 530 GPS receiver with real time kinematic positioning (RTK; swipos GIS/GEO from swisstopo). Acquisition control and data processing were conducted using the GeoAcoustics GS+ software package. Swiss basic hydrological monitoring network (BAFU, 2008) were used to normalize water depths to the mean lake level (433.6 m a.s.l.). See Hilbe et al. (2011) for further information. The original bathymetry dataset is available from swisstopo and should be referenced as Hilbe, M., Anselmetti, F. S., Eilertsen, R. S., Hansen, L., & Wildi, W. (2011). Subaqueous morphology of Lake Lucerne (Central Switzerland): implications for mass movements and glacial history. Swiss Journal of Geosciences, 104(3), 425-443
Boron biodistribution for BNCT in the hamster cheek pouch oral cancer model: Combined administration of BSH and BPA
No full textSodium mercaptoundecahydro-closo-dodecaborate (BSH) is being investigated clinically for BNCT. We examined the biodistribution of BSH and BPA administered jointly in different proportions in the hamster cheek pouch oral cancer model. The 3 assayed protocols were non-toxic, and showed preferential tumor boron uptake versus precancerous and normal tissue and therapeutic tumor boron concentration values (70-85ppm). All 3 protocols warrant assessment in BNCT studies to contribute to the knowledge of (BSH+BPA)-BNCT radiobiology for head and neck cancer and optimize therapeutic efficacy.Fil: Garabalino, Marcela Alejandra. Comisión Nacional de Energía Atómica; ArgentinaFil: Heber, Elisa Mercedes. Comisión Nacional de Energía Atómica; ArgentinaFil: Monti Hughes, Andrea. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pozzi, Emiliano César Cayetano. Comisión Nacional de Energía Atómica; ArgentinaFil: Molinari, Ana Julia. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nigg, David W.. Idaho National Laboratory; Estados UnidosFil: Bauer, William. Idaho National Laboratory; Estados UnidosFil: Trivillin, Verónica Andrea. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schwint, Amanda Elena. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
The effects of increased midsole bending stiffness of sports shoes on muscle-tendon unit shortening and shortening velocity: a randomized crossover trial in recreational male runners
No full textBackground: Individual compliances of the foot-shoe interface have been suggested to store and release elastic strain energy via ligamentous and tendinous structures or by increased midsole bending stiffness (MBS), compression stiffness, and resilience of running shoes. It is unknown, however, how these compliances interact with each other when the MBS of a running shoe is increased. The purpose of this study was to investigate how structures of the foot-shoe interface are influenced during running by changes to the MBS of sport shoes.
Methods: A randomised crossover trial was performed, where 13 male, recreational runners ran on an instrumented treadmill at 3.5 m center dot s(-1) while motion capture was used to estimate foot arch, plantar muscle-tendon unit (pMTU), and shank muscle-tendon unit (sMTU) behaviour in two conditions: (1) control shoe and (2) the same shoe with carbon fibre plates inserted to increase the MBS.
Results: Running in a shoe with increased MBS resulted in less deformation of the arch (mean +/- SD; stiff, 7.26 +/- 1.78 degrees; control, 8.84 +/- 2.87 degrees; p <= 0.05), reduced pMTU shortening (stiff, 4.39 +/- 1.59 mm; control, 6.46 +/- 1.42 mm; p <= 0.01), and lower shortening velocities of the pMTU (stiff, - 0.21 +/- 0.03 m center dot s(-1); control, - 0.30 +/- 0.05 m center dot s(-1); p <= 0.01) and sMTU (stiff, - 0.35 +/- 0.08 m center dot s(-1); control, - 0.45 +/- 0.11 m center dot s(-1); p <= 0.001) compared to a control condition. The positive and net work performed at the arch and pMTU, and the net work at the sMTU were significantly lower in the stiff compared to the control condition.
Conclusion: The findings of this study showed that if a compliance of the foot-shoe interface is altered during running (e.g. by increasing the MBS of a shoe), the mechanics of other structures change as well. This could potentially affect long-distance running performance.articl
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