bluuebunny/crossref_metadata_2025 huggingface dataset:
Monte Carlo Calculation Procedure and Its Implementation for Radiation Load Estimation on Russian VVER Reactor Equipment
Authors: Baier Silvio , Konheiser Jörg , Borodkin Pavel , Gazetdinov Azamat , Khrennikov Nikolay
Published: December 2018

Prediction of radiation load parameters (fluence, fluence rate, neutron energy spectrum) of reactor components (e.g., reactor pressure vessel) water-water energetic reactors (known as VVER in Russia) is regulated by the requirements of the Russian normative documents [1]. One of the key measures is the validation of calculated procedures by ex-vessel neutron activation measurements at VVER nuclear power plants. The neutron dosimetry research for every reactor component includes validation calculations by appropriate codes. The standard method was based on the three-dimensional synthesis method with input from results of calculations from the deterministic code DORT [2] coupled with the BUGLE-96T library [3]. It was identified in comparison between experiments and calculations that this method gives different results outside the active core. Hence, the usage of a three-dimensional code is essential. For this reason, the Scientific and Engineering Centre for Nuclear and Radiation Safety wants to use the Monte Carlo code TRAMO for their fluence calculations. Thus, the purpose of this work is the possible application of TRAMO for expert calculations of radiation load parameters of reactor components for all VVER reactor types, verification of results by comparison with other codes (deterministic and Monte Carlo), and validation by neutron activation measured data. The paper presents the main options of the new version of TRAMO for neutron fluence calculations suggested by the Scientific and Engineering Centre for Nuclear and Radiation Safety.
Neutron Fluence Monitoring for Subsequent License Renewal
Authors: Patel Amrit D. , Risner Joel M. , Parks Benjamin T. , Hardgrove Matthew T.
Published: December 2018

The U.S. Nuclear Regulatory Commission (NRC) has been reviewing nuclear power plant license renewal applications for licensees seeking extended operation beyond their original 40-year operating licenses. The NRC has reviewed and approved applications for multiple licensees to continue operating up to 60 years from the issuance of their original operating license. Licensees have shown recent interest in continuing operation up to a total of 80 years, in accordance with the Atomic Energy Act of 1954, as amended. The NRC has been reviewing the technical and regulatory challenges for this subsequent license renewal period. This paper: (1) reviews experience and challenges in applying the NRC’s regulatory framework regarding neutron fluence calculations to the broad variety of neutron fluence applications that support 60-year extended operating licenses, (2) explains the NRC’s basis for developing an aging management program for fluence calculations for 80-year license terms, and (3) discusses planned improvements to regulatory guidance supporting the regulatory framework regarding neutron fluence calculations.
Examination of Core Neutronic Data Generated with the CASL Tools and Impacts on Ex-Core Neutron Exposure Calculations
Authors: Fischer Greg A.
Published: December 2018

The Consortium for Advanced Simulation of Light Water Reactors (known as CASL) is A U.S. Department of Energy program initiated to develop core neutronic, thermal-hydraulic, and crud transport tools based on higher-order methods than those that currently support the operating fleet of nuclear power plants. The objective is to try to find ways to improve plant performance. Core depletion calculations modeling several operating commercial nuclear reactors have been performed with the Consortium tool suite called the Virtual Environment for Reactor Analysis, or VERA. The data from these calculations provide a basis for comparison against currently used data and outputs from existing core neutronics codes. This paper compares predictions of pin power distributions generated by VERA with predictions from nodal diffusion-based core neutronics codes that are used for production calculations and with generic pin power distributions typically used as inputs to dosimetry analyses. The resulting impacts on subsequent neutron transport calculations are provided. The consistency of the VERA-predicted pin power distributions in the axial direction is examined. Axial power distributions calculated by VERA are compared to calculations from the Westinghouse Advanced Nodal Code, and the core-averaged axial power distribution is compared to distributions computed for specific peripheral assemblies calculated by VERA. Taken together, these comparisons provide insight into the degree to which widely used methodological approximations, such as diffusion theory in the core design process, are able to generate accurate predictions of necessary input parameters for fluence and dosimetry analysis.
The VENUS-F Reactor for Nuclear Data Validation
Authors: Krása Antonín , Baeten Peter , Fiorito Luca , Heyse Jan , Kochetkov Anatoly , Kopecky Stefan , Messaoudi Nadia , Paradela Carlos , Schillebeeckx Peter , Stankovskiy Alexey , van den Eynde Gert , Vittiglio Guido , Wagemans Jan
Published: December 2018

Integral experiments for nuclear data validation have been carried out at the fast zero-power reactor VENUS-F at the Belgian Nuclear Research Centre SCK•CEN since 2011. VENUS-F serves as a mock-up of MYRRHA, a fast, lead-bismuth cooled reactor/accelerator-driven system. First, solid lead was used as a coolant simulator and reflector at VENUS-F. In 2016, all lead in VENUS-F fuel assemblies was replaced by bismuth (in total, 625 kg), and a new experimental campaign was carried out with the aim of validating bismuth properties in integral experiments, mainly in the neutron energy region from 1 keV up to 10 MeV. Since 2017, lead and bismuth have been combined in fuel assemblies to simulate lead-bismuth eutectic. An overview of the integral experiments is presented in this paper. Fission rate spatial distributions are compared with Monte Carlo calculations using various nuclear data libraries. The importance of accurate knowledge of material composition is discussed using high-purity bismuth samples (99.99 %) as examples. These were characterized by neutron activation analysis at SCK•CEN, mass spectrometry by the supplier (EVOCHEM), and neutron resonance capture analysis at the GELINA facility of the European Commission Joint Research Centre.
On the Influence of Biological Shielding on Neutron Flux behind Reactor Pressure Vessel
Authors: Košt´ál Michal , Klupák Vít , Rypar Vojtěch , Losa Evžen , Cvachovec František , Jánský Bohumil , Harutunyan Davit , Schulc Martin , Novák Evžen , Zaritskiy Sergey M. , Bresson Anais , Tommy-Martin Michel , Gosmain Cecile-Aline
Published: December 2018

The neutron flux behind the reactor pressure vessel (RPV) is formed by primary transmitted neutrons from the core and also by backscattered neutrons from biological shielding. In the evaluations of neutron flux in the RPV, the knowledge of the reflected neutrons’ share on the total flux is important for correct assessment of possible discrepancies. This paper aims to determine the share of backscattered neutrons in the spectrum behind the RPV and presents new results obtained with an improved fixed source model based on more precise and validated power distribution. Measurements of fast and thermal neutron fluxes in various configurations of biological shielding are realized in a VVER-1000 mock-up in the LR-0 reactor. Additionally, the calculations of the VVER-1000 mock-up are supplemented by calculations of an Électricité de France heavy reflector benchmark that represents arbitrary pressurized water reactor geometry. Comparison of both types of results shows that the LR-0 mock-up measurements are directly applicable, in terms of reactor dosimetry, to other types of pressurized water reactors, regardless of the burn-up and type of fuel they use. It is shown that the amount of backscattered thermal neutrons behind the reactor vessel strongly depends on the distance between the vessel and the concrete shielding. The choice of the data library for calculations influences the results in the thermal region as well.
Supplemental Surveillance Capsule Application for Optimized Power Reactor, OPR1000, in Korea
Authors: Maeng YoungJae , Lim MiJoung , Kim KyungSik , Yoo ChoonSung , Kim Byoung Chul
Published: December 2018

In Korea, the pressurized water reactor (PWR) is the most common nuclear power plant. Twenty-four PWRs are operating commercially or are under construction. According to the public requirements of the reactor pressure vessel (RPV) surveillance program, all PWR plants have surveillance capsules. The current design life of OPR1000 is 40 years. In order to obtain more accelerated embrittlement characteristics of the RPV material, six surveillance capsules were installed at the OPR1000 RPV inner wall in the downcomer region before the plant began operation. However, the lead factor—defined as the ratio of the fast (E > 1.0 MeV) neutron flux at the surveillance capsule to the fast neutron flux at the RPV peak fluence location—had been estimated at about 1.3 MeV. Therefore, it is difficult to obtain the high-dose irradiation embrittlement data for the life extension. To overcome the small lead factors of OPR1000, supplemental surveillance capsules were fabricated and installed at the Westinghouse plant, which has a relatively high lead factor. This paper discusses the fabrication and installation of supplemental surveillance capsules and the expected withdrawal schedule based on neutron transport calculations and dosimetry evaluations.
Practical Considerations for Reactor Spectrum Characterization: Lessons Learned
Authors: Quirk Thomas , Parma Edward J.
Published: December 2018

The Annular Core Research Reactor (ACRR) at Sandia National Laboratories provides experimenters with a unique platform for irradiations. Its central cavity is wide enough to accommodate spectrum-modifying materials, commonly referred to as buckets. The addition of hydrogenous moderators, such as polyethylene or water, can cause considerable thermalization of the free field neutron spectrum. Conversely, thick annular regions of strong, thermal absorbers, such as boron or cadmium, create a faster neutron spectrum inside. Similarly, the gamma-ray fluence can be attenuated by adding high-Z materials or enhanced through radiative capture in cadmium or gadolinium. Novel configurations of buckets allow simultaneous neutron energy spectrum modification and gamma-ray attenuation. As such, different radiation environments can exist at ACRR’s core centerline. Recent efforts have produced detailed characterizations of several neutron- and gamma-ray spectrum-modifying buckets for the ACRR central cavity, including: the free field; the 44-in.-tall lead-boron carbide bucket (fast neutron, attenuated photon); the polyethylene-lead-graphite bucket (thermalized neutrons, attenuated photon); and the Cd-Poly bucket (cadmium polyethylene lined bucket used to enhance photon production). Dedicated opportunities to perform multiple characterizations occurred somewhat infrequently, which afforded the authors the ability to hone techniques for performing these tests. Each neutron spectrum characterization generally followed both ASTM E720, Standard Guide for Selection and Use of Neutron Sensors for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics, and ASTM E721, Standard Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics. This paper presents some practical lessons learned throughout these characterizations—both experimental and computational.
Establishment of CORONA Academy as Common Source of Knowledge in the Area of VVER Technology
Authors: Mitev Mladen R. , Manolova Mariya A. , Pironkov Lyubomir T.
Published: December 2018

Preserving and further developing of nuclear competencies, skills, and knowledge related to water-water energy reactor (or VVER) technology (from the Russian, vodo-vodyanoi energetichesky reaktor)—a technology used by many European Union countries—is among the main objectives of the CORONA II project (“Enhancement of training capabilities in VVER technology through establishment of VVER training academy”). The project is financed under the Horizon 2020 Research and Innovation Programme. This objective will be achieved by the establishment of a state-of-the-art regional training center for VVER competence—the CORONA Academy. The academy will act as a management system for VVER-related knowledge as well as serving as an on-demand training provider. These particular objectives will be achieved using a created knowledge management portal and the implementation of e-learning tools within a distance training system. Knowledge about reactor dosimetry tools and methods is highly recognized due to their great importance to the long-term operation and decommissioning activities that are ongoing in many VVER-operating countries around the world. For this reason, a number of topics related to dosimetry and pressure vessel state assessment are included in training programs for nuclear professionals and subcontractors. The ability of the Online Multimedia Training Course on VVER Reactor Pressure Vessel Embrittlement and Integrity Assessment, developed by a joint effort of Joint Research Centre, Institute for Energy and Transport and the International Atomic Energy Agency to provide adequate ground for transfer of reactor dosimetry knowledge, is also evaluated in the training.
Assessment of Novel Techniques for Nuclear Data Evaluation
Authors: Helgesson Petter , Neudecker Denise , Sjöstrand Henrik , Grosskopf Michael , Smith Donald L. , Capote Roberto
Published: December 2018

The quality of evaluated nuclear data can be impacted by, for example, the choice of the evaluation algorithm. The objective of this work is to compare the performance of the evaluation techniques generalized least squares (GLS), generalized nonlinear least squares in the parameter domain (GLS-P), and the Unified Monte Carlo evaluation algorithms B (UMC-B) and G (UMC-G), by using synthetic data. In particular, the effects of model defects are investigated. For small model defects, UMC-B and GLS-P are found to perform best, while these techniques yield the worst results for a significantly defective model; in particular, they seriously underestimate the uncertainties. If UMC-B is augmented with Gaussian processes, it performs distinctly better for a defective model but is more susceptible to an inadequate experimental covariance estimate.
Design of Separated Element Reflector Experiments in CROCUS: PETALE
Authors: Lamirand Vincent , Perret Gregory , Radman Stefan , Siefman Daniel , Frajtag Pavel , Hursin Mathieu , Gruel Adrien , Leconte Pierre , Blaise Patrick , Pautz Andreas
Published: December 2018

The present article describes the preliminary design studies for PETALE (Programme d’Etude en Transmission de l’Acier Lourd et ses Eléments), an oncoming experimental program in the CROCUS reactor. Within the framework of the Venus-Eole-Proteus collaboration, PETALE continues the nuclear data validation efforts required for modeling GEN-III pressurized water reactors with heavy steel reflectors. The inelastic scattering cross sections at around 1 MeV of iron-56, as well as nickel and chromium isotopes, will be studied separately. The water reflector will be replaced successively by sheets of stainless steel alloy and pure metals—iron, nickel, and chromium. Data will be extracted from two sources: the measured neutron flux attenuation using adequate dosimetry and possibly fission chambers in the metal reflector and from the criticality effects of these reflectors. PETALE will also be used with nuclear data adjustment methods because, as a separated and elemental integral experiment, it allows the limiting of compensation effects in the nuclear data adjustments. A parametric study has been carried out with MCNPX for assessing the optimal configuration and the feasibility of the experiments. This study is the first step toward optimizing the global sensitivity of the experiments to the reactions in the energy range of interest, thus assessing the measurements’ target uncertainties and preparing further use of the program results.
Experimental and Computational Validation of RAPID
Authors: Roskoff Nathan J. , Haghighat Alireza , Mascolino Valerio
Published: December 2018

The Real-Time Analysis for Particle Transport and In-Situ Detection (RAPID) code system utilizes the multi-stage response-function transport approach with the fission matrix method for neutronics simulation of nuclear systems. RAPID performs real-time calculations by utilizing pre-calculated databases for different enrichments, burnups, and cooling times. This paper discusses the validation of RAPID using the U.S. Naval Academy's subcritical reactor facility. Computational validation is performed by detailed comparison with a Monte Carlo N-Particle reference calculation, and experimental validation is performed using both in-core and ex-core neutron measurements with different helium-3 (3He) proportional counters. These measurements and associated calculations have demonstrated that RAPID achieves accurate results in real time.
1-MeV Equivalent Silicon Damage Studies at the White Sands Missile Range Fast Burst Reactor
Authors: Flanders Thomas M. , Sparks Mary Helen
Published: December 2018

In the last half of the 1970s, a variety of research reactor facilities were used to perform studies on the radiation hardness of solid-state devices. Due to the lack of a cohesive method for evaluating and measuring the relative damage effectiveness of the various environments, results of the studies varied widely, and it was difficult to compare the results from one facility with results obtained at a different facility. In response, the testing community developed a standard to evaluate an equivalent damage concept, which would provide a common basis for damage studies. ASTM E722, Standard Practice for Characterizing Neutron Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence for Radiation-Hardness Testing of Electronics, has become the accepted standard for the test facilities. In this paper we document the significant changes to this response function, other functions commonly used with transport calculations, and the effect of the changes on evaluating the 1-MeV equivalent silicon displacement damage with a common set of reactor spectra. The data presented are of value to test programs that have used one or more of the facilities for an extended life-cycle test program.
Spectrum Adjustment Results for Three Environments in the ACRR Central Cavity Using a Genetic Algorithm
Authors: Vega Richard M. , Parma Edward J.
Published: December 2018

Presented in this report is the description of a new method for neutron energy spectrum adjustment that uses a genetic algorithm to minimize the difference between calculated and measured reaction probabilities. The reaction probability is the integral over all energies of the product of the microscopic reaction cross section with the neutron fluence. The measured reaction probabilities are found using neutron activation analysis. The method adjusts a trial spectrum provided by the user that typically is calculated using a neutron transport code such as Monte Carlo N-Particle. Observed benefits of this method over currently existing methods include: (a) the reduction in unrealistic artifacts in the spectral shape when compared to iterative unfold approaches such as are used in the SAND-II code or to least squares approaches when an accurate prior spectrum covariance is not available; and (b) a reduced sensitivity to increases in the energy resolution of the derived spectrum. This report presents the adjustment results for various spectrum-altering bucket environments in the central cavity of the Annular Core Research Reactor. In each case, the results are compared to those generated using LSL-M2, which is a code commonly used for spectrum adjustment. The genetic algorithm produces spectrum-averaged reaction probabilities comparable to those resulting from LSL-M2. The splicing of local segments of the a priori spectrum, which is part of the genetic algorithm, permits the resulting spectrum adjustment to avoid introducing severe narrow energy-width shape artifacts without the requirement of a covariance matrix for the prior spectrum.
Testing of the Retrospective Dosimetry Procedure Based on Niobium Extraction from VVER-1000 Cladding Material Samples after Their Irradiation in Research Reactor
Authors: Kochkin Viacheslav N. , Dmitrieva Natalia A. , Reshetnikov Alexandr A. , Erak Dmitry Yu. , Pesnya Yuriy E. , Nasonov Vladimir A.
Published: December 2018

At present, many VVER-1000 reactors in Russia are approaching the end of their design lifetime. Therefore, the problem of their lifetime extension is of immediate interest. Precise evaluation of neutron fluence with E greater than 0.5 MeV at the reactor pressure vessel (RPV) wall is one of the main issues in the lifetime extension process. One of the most reliable experimental techniques that could be used for the refinement of fast neutron fluence value on RPV is the investigation of samples from RPV cladding with approximately 1 % niobium (Nb) content. It is necessary to validate this technique before taking samples from the RPV cladding of reactors currently in operation. Toward this goal, a dosimetry experiment has been carried out at Russia’s Kurchatov Institute. The main idea of the experiment was to compare 93mNb activity in niobium dosimeters and in cladding samples irradiated together to a certain fluence in the research reactor. Another goal was to measure and compare 54Mn activity formed as a result of 54Fe(n,p) reaction in an irradiated RPV material and in iron dosimeters. This task is important due to the widespread use of this technique for the study of the surveillance sets of Russian VVER-440 and VVER-1000 reactors, which are not equipped with a sufficient number of neutron dosimeters.
Predicting Spectrum Averaged Cross Sections in Prompt Fission Neutron Fields
Authors: Capote Roberto , Trkov Andrej
Published: December 2018

New non-model evaluations of prompt fission neutron spectra (PFNS) for thermal neutron induced fission on 233,235U and 239Pu targets have been recently proposed based on an available experimental database. The evaluated PFNS have been validated using measured spectrum averaged cross sections (SACS) and evaluated dosimetry cross sections from the International Reactor Dosimetry and Fusion File v1.05 library. A systematic is derived that predicts the SACS ratio in different PFNS as a function of the E50 % energy for each reaction. The proposed systematic is used to predict difficult to measure or discrepant values of (n,p) and (n,2n) threshold dosimetry reactions in 235U(nth,f) and 252Cf(sf) prompt fission neutron fields based on existing measurements. Parabolic dependence of selected SACS on the average energy of the neutron field is proposed and used to predict the expected SACS in the 239Pu(nth,f) prompt fission neutron field. Independence of the SACS ratio on the neutron field is experimentally confirmed for reactions with E50 % approximately equal to the PFNS average energy. Such independence is used to predict SACS for 235U(n,f), 239Pu(n,f), 10B(n,α), and 237Np(n,f) reactions in 233U(nth,f) and 239Pu(nth,f) prompt fission neutron fields.
Advanced Neutron Dosimetry on VVER-440 Aimed to Reactor Equipment Load Evaluation during Lifetime Prolongation
Authors: Borodkin Pavel , Gazetdinov Azamat , Khrennikov Nikolay , Konheiser Jörg , Dzhalandinov Alexander , Sidorov Alexander , Aleshin Sergey , Zaritskiy Sergey M. , Egorov Alexander L. , Kochkin Vyacheslav N. , Erak Dmitry Yu. , Panferov Pavel , Makhotin Denis
Published: December 2018

The lifetime of nonrestorable reactor equipment (e.g., reactor pressure vessels, in- and ex-vessel constructions, reactor support structures) of a first-generation water-water energetic reactor, VVER-440, may restrict plant life as a whole. Service life extension has affected the first generation of VVER-440 type reactors. Today, all Russian first-generation VVER-440s that have been in operation more than 45 years run with reduced cores by using dummy assemblies, except reactor Unit 4 of the Novovoronezh nuclear power plant. In comparison with other power units, the full-core loading scheme of this unit results in the highest neutron fluence accumulated over the whole operation period. Another important aspect of dosimetry research on Unit 4 of the Novovoronezh nuclear power plant reactor is the verification and validation of calculational methods used for the prediction of the maximum neutron fluence on the VVER-440 pressure vessel.
Fast Two-Parametric Spectrometric System for Experimental MSR/FHR Reactor Dosimetry
Authors: Matěj Zdeněk , Košt´ál Michal , Mravec Filip , Pavelek Martin , Herman Ondřej , Veškrna Martin , Přenosil Václav , Cvachovec František , Losa Evžen
Published: December 2018

The neutron fluence load in the structural components of reactor systems is crucial for issues of reactor dosimetry. The neutron spectrum in the construction of light-water reactor systems is modified by water and iron, whereas the spectrum in advanced molten salt/fluoride salt reactor systems is shifted by fluoride salts and graphite. The majority of commercial nuclear power plants are light-water reactors, where the neutron spectra have been examined many times. In case of progressive technologies, as molten salt/fluoride salt, neutron spectra are measured only rarely. Therefore, a series of experiments with a fast two-parametric spectrometric system were performed in an LR-0 reactor in order to analyze the effect of graphite and fluorides on neutron spectrum.
Prefrontal–Bed Nucleus Circuit Modulation of a Passive Coping Response Set
Authors: Johnson Shane B. , Emmons Eric B. , Lingg Ryan T. , Anderson Rachel M. , Romig-Martin Sara A. , LaLumiere Ryan T. , Narayanan Nandakumar S. , Viau Victor , Radley Jason J.
Published: December 2018

One of the challenges facing neuroscience entails localization of circuits and mechanisms accounting for how multiple features of stress responses are organized to promote survival during adverse experiences. The rodent medial prefrontal cortex (mPFC) is generally regarded as a key site for cognitive and affective information processing, and the anteroventral bed nuclei of the stria terminalis (avBST) integrates homeostatic information from a variety of sources, including the mPFC. Thus, we proposed that the mPFC is capable of generating multiple features (endocrine, behavioral) of adaptive responses via its influence over the avBST. To address this possibility, we first optogenetically inhibited input to avBST from the rostral prelimbic cortical region of mPFC and observed concurrent increases in immobility and hypothalamo–pituitary–adrenal (HPA) output in male rats during tail suspension, whereas photostimulation of this pathway decreased immobility during the same challenge. Anatomical tracing experiments confirmed projections from the rostral prelimbic subfield to separate populations of avBST neurons, and from these to HPA effector neurons in the paraventricular hypothalamic nucleus, and to aspects of the midbrain periaqueductal gray that coordinate passive defensive behaviors. Finally, stimulation and inhibition of the prelimbic–avBST pathway, respectively, decreased and increased passive coping in the shock-probe defensive burying test, without having any direct effect on active coping (burying) behavior. These results define a new neural substrate in the coordination of aresponse setthat involves the gating of passive, rather than active, coping behaviors while restraining neuroendocrine activation to optimize adaptation during threat exposure.

SIGNIFICANCE STATEMENTThe circuits and mechanisms accounting for how multiple features of responses are organized to promote adaptation have yet to be elucidated. Our report identifies a prefrontal–bed nucleus pathway that organizes aresponse setcapable of gating passive coping behaviors while concurrently restraining neuroendocrine activation during exposure to inescapable stressors. These data provide insight into the central organization of how multiple features of responses are integrated to promote adaptation during adverse experiences, and how disruption in one neural pathway may underlie a broad array of maladaptive responses in stress-related psychiatric disorders.
ARL13B, a Joubert Syndrome-Associated Protein, Is Critical for Retinogenesis and Elaboration of Mouse Photoreceptor Outer Segments
Authors: Dilan Tanya L. , Moye Abigail R. , Salido Ezequiel M. , Saravanan Thamaraiselvi , Kolandaivelu Saravanan , Goldberg Andrew F.X. , Ramamurthy Visvanathan
Published: December 2018

Mutations in the Joubert syndrome-associated small GTPase ARL13B are linked to photoreceptor impairment and vision loss. To determine the role of ARL13B in the development, function, and maintenance of ciliated photoreceptors, we generated a pan-retina knock-out (Six3-Cre) and a rod photoreceptor-specific inducible conditional knock-out (Pde6g-CreERT2) of ARL13B using murine models. Embryonic deletion of ARL13B led to defects in retinal development with reduced cell proliferation. In the absence of ARL13B, photoreceptors failed to develop outer segment (OS) membranous discs and axonemes, resulting in loss of function and rapid degeneration. Additionally, the majority of photoreceptor basal bodies did not dock properly at the apical edge of the inner segments. The removal of ARL13B in adult rod photoreceptor cells after maturation of OS resulted in loss of photoresponse and vesiculation in the OS. Before changes in photoresponse, removal of ARL13B led to mislocalization of rhodopsin, prenylated phosphodiesterase-6 (PDE6), and intraflagellar transport protein-88 (IFT88). Our findings show that ARL13B is required at multiple stages of retinogenesis, including early postnatal proliferation of retinal progenitor cells, development of photoreceptor cilia, and morphogenesis of photoreceptor OS discs regardless of sex. Last, our results establish a need for ARL13B in photoreceptor maintenance and protein trafficking.

SIGNIFICANCE STATEMENTThe normal development of photoreceptor cilia is essential to create functional, organized outer segments with stacked membrane discs that house the phototransduction proteins necessary for sight. Our study identifies a complex role for ARL13B, a small GTPase linked to Joubert syndrome and visual impairment, at various stages of photoreceptor development. Loss of ARL13B led to defects in retinal proliferation, altered placement of basal bodies crucial for components of the cilium (transition zone) to emanate, and absence of photoreceptor-stacked discs. These defects led to extinguished visual response and dysregulated protein trafficking. Our findings show the complex role ARL13B plays in photoreceptor development, viability, and function. Our study accounts for the severe retinal impairment observed in ARL13B-linked Joubert syndrome patients.
Upregulation of Anandamide Hydrolysis in the Basolateral Complex of Amygdala Reduces Fear Memory Expression and Indices of Stress and Anxiety
Authors: Morena Maria , Aukema Robert J. , Leitl Kira D. , Rashid Asim J. , Vecchiarelli Haley A. , Josselyn Sheena A. , Hill Matthew N.
Published: December 2018

Increased anandamide (AEA) signaling through inhibition of its catabolic enzyme fatty acid amide hydrolase (FAAH) in the basolateral complex of amygdala (BLA) is thought to buffer against the effects of stress and reduces behavioral signs of anxiety and fear. However, examining the role of AEA signaling in stress, anxiety, and fear through pharmacological depletion has been challenging due to the redundant complexity of its biosynthesis and the lack of a pharmacological synthesis inhibitor. We developed a herpes simplex viral vector to rapidly yet transiently overexpress FAAH specifically within the BLA to assess the impact of suppressing AEA signaling on stress, fear, and anxiety in male rats. Surprisingly, FAAH overexpression in BLA dampened stress-induced corticosterone release, reduced anxiety-like behaviors, and decreased conditioned fear expression. Interestingly, depleting AEA signaling in the BLA did not prevent fear conditioning itself or fear reinstatement. These effects were specific to the overexpression of FAAH because they were reversed by intra-BLA administration of an FAAH inhibitor. Moreover, the fear-suppressive effects of FAAH overexpression were also mitigated by intra-BLA administration of a low dose of a GABAAreceptor antagonist, but not an NMDA/AMPA/kainate receptor antagonist, suggesting that they were mediated by an increase in GABAergic neurotransmission. Our data suggest that a permissive AEA tone within the BLA might gate GABA release and that loss of this tone through elevated AEA hydrolysis increases inhibition in the BLA, which in turn reduces stress, anxiety, and fear. These data provide new insights on the mechanisms by which amygdalar endocannabinoid signaling regulates emotional behavior.

SIGNIFICANCE STATEMENTAmygdala endocannabinoid signaling is involved in the regulation of stress, anxiety, and fear. Our data indicate that viral-mediated augmentation of anandamide hydrolysis within the basolateral amygdala reduces behavioral indices of stress, anxiety, and conditioned fear expression. These same effects have been previously documented with inhibition of anandamide hydrolysis in the same brain region. Our results indicate that the ability of anandamide signaling to regulate emotional behavior is nonlinear and may involve actions at distinct neuronal populations, which could be influenced by the basal level of anandamide. Modulation of anandamide signaling is a current clinical therapeutic target for stress-related psychiatric illnesses, so these data underscore the importance of fully understanding the mechanisms by which anandamide signaling regulates amygdala-dependent changes in emotionality.
El maíz en Italia, siglos XVI-XIX: precios, mercados y haciendas agrícolas (dos casos de estudio: Lombardía y Umbría)
Authors: Mocarelli Luca , Vaquero Piñeiro Manuel
Published: December 2018

El presente estudio tiene por objetivo presentar algunos aspectos clave que nos ayuden a comprender la introducción y expansión del maíz en Lombardía y Umbría en los siglos XVI y XIX, dos regiones emblemáticas en lo que concierne a su historia en Italia. El trabajo utiliza material de archivo inédito para comprobar la validez de una serie de presupuestos de investigación. En primer lugar, la cronología de la introducción del nuevo cultivo, un proceso histórico que, sin duda, implicó la acuñación de nuevas palabras para designar un alimento desconocido hasta la segunda mitad del siglo XVI. Veremos luego las rutas que siguió la “revolución del maíz” en Italia, atendiendo al papel jugado en este sentido por los grandes propietarios de tierra. Otro tema de interés que trataremos son los cambios que la nueva planta introdujo en la estructura productiva, o la forma en que su consumo modificó el tradicional funcionamiento de los mercados de cereal, tanto urbanos como rurales, al favorecer el desarrollo de las haciendas y la aparición de mercaderes especializados. Desde este punto de vista, un aspecto central de nuestro estudio será la posición del maíz en la formacion de ese mercado de cereales. Por esta razón, la investigacion presenta toda una serie de datos estadísticos que demuestran la validez de la tesis relativa a la integración de los circuitos comerciales y, lo que es más emblemático, la perfecta correlación en ellos de los precios. Al respecto, la evolucion de esos precios, tanto del trigo como del maíz, pondrán de relieve la integración de amplios espacios comerciales en la Italia de los siglos XVIII y XIX.
El maíz en el sistema agrario y en la alimentación en Galicia, siglos XVII-XIX
Authors: Saavedra Pegerto
Published: December 2018

El sistema agropecuario vigente en muchas comarcas de Galicia al filo de 1600 notó transformaciones decisivas con la difusión del maíz desde la década de 1630. La planta americana no se convirtió en un cultivo más al lado de los ya existentes, sino que, con ritmos distintos según los territorios, desplazó al mijo y en ocasiones a los cereales de invierno y afectó a las diferentes piezas del complejo tecnológico que caracterizaba la economía rural, desde los usos del monte comunal hasta la estructura y niveles de la cabaña ganadera, y desde el calendario agrario a la división sexual de los diversos trabajas. Impulsado por los campesinos, el maíz transformó el paisaje agrario y el sistema alimenticio de las aldeas en las que se generalizó, a pesar de su escaso aprecio social. En efecto, las contabilidades y otras fuentes monásticas ponen de manifiesto que solo consumían el cereal americano aquellas familias que no tenían suficiente centeno, lo que creó identidades sociales derivadas del tipo de pan que se cocía en los hogares, pues otra cuestión a destacar es que el maíz, a imitación de lo que se practicaba el mijo, se utilizó fundamentalmente en forma de pan, lo que contribuyó a evitar la difusión de la pelagra en comarcas en las que llegó a convertirse casi en el único cereal que se cultivaba y comía.
Adjusting preoperative risk models of post heart transplant survival to a European cohort in the age of a new cardiac allocation score in Europe
Authors: Sargut Tarik Alp , Pergantis Panagiotis , Knosalla Christoph , Knierim Jan , Hummel Manfred , Falk Volkmar , Schoenrath Felix
Published: December 2018

Background

Several risk models target the issue of posttransplant survival, but none of them have

been validated in a large European cohort. This aspect is important, in a time of the planned change of the Eurotransplant allocation system to a scoring system.

Material and Methods

Data of 761 heart transplant recipients from the Eurotransplant region with a total follow up of 5027 patient-years were analyzed. We assessed 30-day to 10-year freedom from graft failure. Existing post-transplant mortality risk models, IMPACT, Meld-XI and Columbia Risk Stratification Score were (RSS) were evaluated. A new risk model was created and the predictive accuracy was compared with the existing risk scores, with a focus on LVAD patients.

Results

Thirty-day, 1-year, 5-year and 10-year rates of freedom from graft failure were 78.3±1.5%, 68.8±1.71%, 59.1±1.8% and 44.1±1.9. The 1-year incidence of graft failure varied from 14.1% to 50% (RSS), from 22.9% to 57.1 (IMPACT) and from 24.9% to 42.6% using MELD-XI. Our newly adjusted risk score showed an improved area under the curve (AUC) of 0.69 (95% CI 0.64-0.72) with better discrimination in the intermediate to moderate risk cohort (CABDES Score).

Conclusion

IMPACT, Meld-XI and RSS were suitable to predict posttransplant graft failure only in a high and low risk cohort. CABDES Score, might be an alternative scoring system, with donor age and eGFR beeing the strongest predictors. Implementation of the IMPACT score within the new Eurotransplant Cardiac Allocation Score for patient prioritization for heart transplantation, should be reevaluated.
Žydų muziejus Vilniuje: pirmieji bandymai įprasminti trauminę patirtį ir skatinti tvarią atmintį
Authors: Latvytė-Gustaitienė Neringa
Published: December 2018

[full article and abstract in Lithuanian; abstract in English]

The Jewish Museum in Vilnius, founded in the autumn on 1944 upon the initiative of the Holocaust survivors, played a special place in the collective memory of Litvaks. It was the first and unique attempt in Eastern Europe to (publicly) present the massive killings of Jews by the Nazi and local collaborators, primarily by shooting, and by annihilating themat Nazi concentration camp gas chambers, the plunder of cultural and spiritual values, and the efforts of survivors to collect and preserve Jewish heritage remnants. The museum became a certain genius loci, that is, a lively place giving both material and mental meaning to the Jewish community, creating emotions, providing a certain sense of security and encouraging dialogue. Unfortunately, the Soviet government failed to understand the uniqueness of the museum and appreciate the importance of its activities. This memory institution was closed down in 1949, in the midst of an anti-Semitic campaign. The collections and exhibits accumulated in the museum were distributed to Lithuanian museums, archives and libraries. Thus, the Jewish history, culture and traditions and the very theme of mass murder of the Jews were pushed to the margins of history for the period of 40 years.

(De)codable with double-memory standards, the so-called counter-memory of kitchen communities or reprocessed memory was rather wretchedly presented in public were maintained as a counterweight to the hegemonic narrative. It was under the influence of the latter that in September of 1989 the Lithuanian State Jewish Museum was restored. The first exhibition named “Catastrophe”, mounted in the newly restored museum, was the only Holocaust exhibition in the former Soviet bloc countries. Later it was granted the status of a separate museum branch, called the Holocaust exposition. Renovated in 2010, the exhibition has retained the features of the post-war Jewish Museum exhibition. As such, it attracts a lot of visitors and encourages sustainable memory.

The aim of the article is to introduce the circumstances related to the establishment of the post-war Jewish Museum in Vilnius, distinguishing its peculiarities by demonstrating the attempts and methods of the Holocaust survivors to publicly introduce the traumatic experiences of the community, as opposed to the discourse shaped by the Soviet regime, as well as showing the exclusivity of the memory institution itself in today’s society.
The time-fractional mZK equation for gravity solitary waves and solutions using sech-tanh and radial basic function method
Authors: Guo Min , Dong Haoyu , Liu Jianxin , Yang Hongwei
Published: December 2018

In recent years, we know that gravity solitary waves have gradually become the research spots and aroused extensive attention; on the other hand, the fractional calculus have been applied to the biology, optics and other fields, and it also has attracted more and more attention. In the paper, by employing multi-scale analysis and perturbation methods, we derive a new modified Zakharov–Kuznetsov (mZK) equation to describe the propagation features of gravity solitary waves. Furthermore, based on semi-inverse and Agrawal methods, the integer-order mZK equation is converted into the time-fractional mZK equation. In the past, fractional calculus was rarely used in ocean and atmosphere studies. Now, the study on nonlinear fluctuations of the gravity solitary waves is a hot area of research by using fractional calculus. It has potential value for deep understanding of the real ocean–atmosphere. Furthermore, by virtue of the sech-tanh method, the analytical solution of the time-fractional mZK equation is obtained. Next, using the above analytical solution, a numerical solution of the time-fractional mZK equation is given by using radial basis function method. Finally, the effect of time-fractional order on the wave propagation is explained.
Factors of Mutual Impact of Innovative Startups and the Regional Environment
Authors: Arzhenovskiy Igor V.
Published: December 2018

Introduction. The growing dependence of regional economies on innovation determines the importance of regional innovation policy, it being an integral part of regional economic policy. Within its framework, a constant assessment of mutual impact of the factors of regional development and successful startups is necessary. The goal of this study is to identify such basic factors.

Materials and Methods. Regional socio-economic complexes of the Republic of Mordovia, Nizhny Novgorod Region and Samara Region are considered as the research object. Regional primary and secondary statistics on the research topic, legislative and regulatory acts of the federal and regional levels form the information basis of the study. The methods of system analysis, economic statistics, expert survey, economic and mathematical modeling as well as cognitive modeling were employed.

Results. The primary and final lists of factors of mutual impact of innovative startups and the regional environment have been compiled. The features of modern startups and their interaction with the external environment have been exposed. The cause-and-effect relations between the factors have been identified. A quantitative and qualitative analysis of the factors, their grouping and classification for the subsequent modeling of innovative processes in the region has been performed.

Discussion and Conclusion. The results obtained serve as the basis for correlation and regression analysis and the subsequent provision of a cognitive model of the regional innovation process that takes into account the peculiarities of the regions under consideration. The verified cognitive model makes it possible to construct prognostic scenarios of the impact of innovations on the regional growth and the influence of the regional environment on the growth of innovations, to conduct a justification, a comparative analysis and an assessment of the consequences of management decisions on development of the regional infrastructure to support entrepreneurship as well as to evaluate the adaptability of innovative startups to changes in external and internal environment factors.
Quality of Life in the Republic of Sakha (Yakutia): Rating of the Municipal Districts
Authors: Gordyachkova Olga V. , Pechetova Tatiana I.
Published: December 2018

Introduction. In Russia, the issue of disparity in the quality of life between the regions remains urgent. To a large extent, it is manifested in the regions themselves, and is due to an objective factor of geographical location. The purpose of this study is to give a rating assessment of the quality of life in the largest constituent entity of the Russian Federation, the Republic of Sakha (Yakutia).

Materials and Methods. The information base of the study includes open data from the Territorial Body of the Federal State Statistics Service for the Republic of Sakha (Yakutia), and the ratings by Profile magazine and RIA Rating agency. To assess the quality of life in the municipal districts of the Republic of Sakha (Yakutia), the sum-of-the-places rating method was adopted.

Results. According to the ranking of the municipal districts of the Republic of Sakha (Yakutia), the leaders (the capital and industrially developed regions) and outsiders (areas in the Arctic zone of Yakutia) were identified. It has been revealed that despite the efforts undertaken by the regional authorities, there is a significant gap in the quality of life in the Republic of Sakha (Yakutia). The study has shown that there is no official or generally accepted system for assessing the quality of life. Moreover, there is no common understanding of indicators that comprehensively characterize the quality of life.

Discussion and Conclusion. The study has confirmed the thesis that industrial development in association with development of the territory and formation of the infrastructure help improve the quality of life. On the other hand, industrial development and increased urbanization exacerbate the problem of safety of residents and make relevant the issues related to the provision of quality housing in extreme climatic conditions. The results of the rating can be used by the government of the Republic of Sakha (Yakutia) and the municipal authorities in order to provide solutions for managing the quality of life.