bluuebunny/crossref_metadata_2025_split huggingface dataset:
Complex IV-deficient Surf1−/− mice initiate mitochondrial stress responses
Authors: Pulliam Daniel A. , Deepa Sathyaseelan S. , Liu Yuhong , Hill Shauna , Lin Ai-Ling , Bhattacharya Arunabh , Shi Yun , Sloane Lauren , Viscomi Carlo , Zeviani Massimo , Van Remmen Holly 
Published: June 2014

Mutations in SURF1 (surfeit locus protein 1) COX (cytochrome c oxidase) assembly protein are associated with Leigh's syndrome, a human mitochondrial disorder that manifests as severe mitochondrial phenotypes and early lethality. In contrast, mice lacking the SURF1 protein (Surf1−/−) are viable and were previously shown to have enhanced longevity and a greater than 50% reduction in COX activity. We measured mitochondrial function in heart and skeletal muscle, and despite the significant reduction in COX activity, we found little or no difference in ROS (reactive oxygen species) generation, membrane potential, ATP production or respiration in isolated mitochondria from Surf1−/− mice compared with wild-type. However, blood lactate levels were elevated and Surf1−/− mice had reduced running endurance, suggesting compromised mitochondrial energy metabolism in vivo. Decreased COX activity in Surf1−/− mice is associated with increased markers of mitochondrial biogenesis [PGC-1α (peroxisome-proliferator-activated receptor γ co-activator 1α) and VDAC (voltage-dependent anion channel)] in both heart and skeletal muscle. Although mitochondrial biogenesis is a common response in the two tissues, skeletal muscle has an up-regulation of the UPRMT (mitochondrial unfolded protein response) and heart exhibits induction of the Nrf2 (nuclear factor-erythroid 2-related factor 2) antioxidant response pathway. These data are the first to show induction of the UPRMT in a mammalian model of decreased COX activity. In addition, the results of the present study suggest that impaired mitochondrial function can lead to induction of mitochondrial stress pathways to confer protective effects on cellular homoeostasis.
Research on dynamic real‐time error correction method using Wiener‐based neural network
Authors: Wu Dehui , You Dehai , Chen Jun , Li Chao 
Published: June 2014

A novel structure of Wiener‐based neural network is proposed and applied to correct the dynamic real‐time error for the improvement of the sensor's dynamic performance. First, the compensation filter was established based on the principle of inverse model and was described by a dynamic linear‐static nonlinear cascade (Wiener model). Then, the neural network structure was devised and the network weights were accord with the parameters of the compensation filter. Followed that, some experimental devices were designed for dynamic calibration of the uIRt/c infrared temperature sensor. Finally, the identification of compensation filter was achieved by network iteration and the actual calibration data of the uIRt/c were made use of in the testing experiments. The results show that the stabilising time of the sensor is reduced to less than 7 ms from 27 ms and the dynamic performance is obviously improved after compensation.
Self‐matched high‐Q reconfigurable antenna concept for mobile terminals
Authors: Bahramzy Pevand , Jagielski Ole , Svendsen Simon , Pedersen Gert F. 
Published: June 2014

This study presents reconfigurable antenna design for a front end (FE) that has separate transmit (Tx) and receive (Rx) path. In such an FE, the Tx and Rx antennas can be content with covering only the transmit and receive channels in a frequency band. Therefore they can be quite narrow‐band. Narrow‐band antennas can exhibit high losses, because of the relative high current density per area and limited tuning/matching component Q. To address this, a self‐matched antenna design is introduced, having the tunable capacitor as the only physical component. The Tx and Rx narrow‐band antennas are designed to cover the frequency range 1710–2170 MHz. Metrics as for example, impedance bandwidth and efficiency are obtained both in simulations and measurements.
AC creeping discharges propagating over solid–gas interfaces
Authors: Sadaoui Fares , Beroual Abderrahmane 
Published: June 2014

This study is aimed at the characterisation of surface discharges propagating over different solid materials namely glass, bakelite and epoxy resin immersed in three gases and their mixtures (namely SF6, N2 and CO2, SF6/N2 and SF6/CO2) under AC voltage (50 Hz) in a point‐plane electrode system. It is shown that the stopping length of discharges (Lf) increases linearly with the applied voltage and decreases when the gas pressure is increased. Lf is longer in CO2 and N2 than in SF6 [Lf(N2) > Lf(CO2) > Lf(SF6)]; and the increase of SF6 content in the investigated mixtures leads to a significant decrease of Lf. Also, for a given gas, Lf is slightly longer with glass and bakelite than that with epoxy resin indicating that the higher the dielectric constant, the longer the discharge is. Thus, the density of the discharge branches and Lf reduce when the thickness of insulators increases and/or their dielectric constant decreases. Such observations evidence the implication of capacitive charge effect and electric field in the development of creeping discharges.
Applicability of 3D Monte Carlo simulations for local values calculations in a PWR core
Authors: Bernard Franck , Cochet Bertrand , Jinaphanh Alexis , Jacquet Olivier 
Published: June 2014

As technical support of the French Nuclear Safety Authority, IRSN has been developing the MORET Monte Carlo code for many years in the framework of criticality safety assessment and is now working to extend its application to reactor physics. For that purpose, beside the validation for criticality safety (more than 2000 benchmarks from the ICSBEP Handbook have been modeled and analyzed), a complementary validation phase for reactor physics has been started, with benchmarks from IRPHEP Handbook and others.
In particular, to evaluate the applicability of MORET and other Monte Carlo codes for local flux or power density calculations in large power reactors, it has been decided to contribute to the “Monte Carlo Performance Benchmark” (hosted by OECD/NEA). The aim of this benchmark is to monitor, in forthcoming decades, the performance progress of detailed Monte Carlo full core calculations. More precisely, it measures their advancement towards achieving high statistical accuracy in reasonable computation time for local power at fuel pellet level. A full PWR reactor core is modeled to compute local power densities for more than 6 million fuel regions.
This paper presents results obtained at IRSN for this benchmark with MORET and comparisons with MCNP. The number of fuel elements is so large that source convergence as well as statistical convergence issues could cause large errors in local tallies, especially in peripheral zones. Various sampling or tracking methods have been implemented in MORET, and their operational effects on such a complex case have been studied. Beyond convergence issues, to compute local values in so many fuel regions could cause prohibitive slowing down of neutron tracking. To avoid this, energy grid unification and tallies preparation before tracking have been implemented, tested and proved to be successful. In this particular case, IRSN obtained promising results with MORET compared to MCNP, in terms of local power densities, standard deviations and computing times.
Large scale ab initio calculations of extended defects in materials: screw dislocations in bcc metals
Authors: Dézerald Lucile , Ventelon Lisa , Willaime François , Clouet Emmanuel , Rodney David 
Published: June 2014

Ab initio methods, based on the Density Functional Theory (DFT), have been extensively used to study point defects and defect clusters in materials. Present HPC resources and DFT codes now allow similar investigations to be performed on dislocations. The study of these extended defects requires not only larger simulation cells but also a higher accuracy because the energy differences, which are involved, are rather small, typically 50-to-100 meV for supercells containing 50-to-500 atoms.
The topology of the Peierls potential of screw dislocations with 1/2 <111>Burgers vector, i.e. the 2D energy landscape seen by these dislocations, is being completely revisited by DFT calculations. From results obtained in all body-centered cubic (bcc) transition metals, except Cr (V, Nb, Ta, Mo, W and Fe), using the PWSCF code, which is part of the Quantum-Espresso package, we concluded that the 2D Peierls potentials have two common features: the single-hump shape of the barrier between two minima of the potential, and the presence of a maximum – and not a minimum as predicted by most empirical potentials – around the split core. In iron, the topology of the Peierls potential is reversed compared to the classical sinusoidal picture: the location of the saddle point and the maximum are indeed inverted with unexpected flat regions.
The first results obtained within the framework of the PRACE project, DIMAIM (DIslocations in Metals using Ab Initio Methods), started at the beginning of 2013, will also be presented. In particular, in order to address the twinning-antitwinning asymmetry often observed in bcc metals and regarded as the major contribution to the breakdown of Schmid's law, we have determined the crystal orientation dependence of the Peierls stress, i.e. the critical stress required for dislocation motion. These computationally most expensive simulations were performed on the PRACE Tier-0 system at Barcelona Supercomputing Center (Marenostrum III). The scalability results using the various parallelization levels of the PWSCF code up to 10 000 cores will be presented.
Reconstruction of Human Monte Carlo Geometry from Segmented Images
Authors: Zhao Kai , Cheng Mengyun , Fan Yanchang , Wang Wen , Long Pengcheng , Wu Yican ,   FDS Team
Published: June 2014

Human computational phantoms have been used extensively for scientific experimental analysis and experimental simulation. This article presented a method for human geometry reconstruction from a series of segmented images of a Chinese visible human dataset. The phantom geometry could actually describe detailed structure of an organ and could be converted into the input file of the Monte Carlo codes for dose calculation.
A whole-body computational phantom of Chinese adult female has been established by FDS Team which is named Rad-HUMAN with about 28.8 billion voxel number. For being processed conveniently, different organs on images were segmented with different RGB colors and the voxels were assigned with positions of the dataset. For refinement, the positions were first sampled. Secondly, the large sums of voxels inside the organ were three-dimensional adjacent, however, there were not thoroughly mergence methods to reduce the cell amounts for the description of the organ. In this study, the voxels on the organ surface were taken into consideration of the mergence which could produce fewer cells for the organs. At the same time, an indexed based sorting algorithm was put forward for enhancing the mergence speed. Finally, the Rad-HUMAN which included a total of 46 organs and tissues was described by the cuboids into the Monte Carlo Monte Carlo Geometry for the simulation.
The Monte Carlo geometry was constructed directly from the segmented images and the voxels was merged exhaustively. Each organ geometry model was constructed without ambiguity and self-crossing, its geometry information could represent the accuracy appearance and precise interior structure of the organs. The constructed geometry largely retaining the original shape of organs could easily be described into different Monte Carlo codes input file such as MCNP. Its universal property was testified and high-performance was experimentally verified
Importance Sampling Implemented in the Code PRIZMA for Deep Penetration and Detection Problems in Reactor Physics
Authors: Kandiev Y.Z. , Zatsepin O.V. 
Published: June 2014

At RFNC-VNIITF a code PRIZMA which has been developed for more than 30 years is used to model radiation transport by the Monte Carlo method. The code implements individual and coupled tracking of neutrons, photons, electrons, positrons and ions in 1D, 2D or 3D geometry. Attendance estimators are used for tallying, i.e., the estimators whose scores are only nonzero from particles which cross a region or surface of interest. Importance sampling is used to make deep penetration and detection calculations more effective. However, its application to reactor analysis appeared peculiar and required further development.
The paper reviews methods used for deep penetration and detection calculations by PRIZMA. It describes in what these calculations differ when applied to reactor analysis and how we compute approximated importance functions and parameters for biased distributions. Methods to control the statistical weight of particles are also discussed.
A number of test and applied calculations which were done for the purpose of verification are provided. They are shown to agree either with asymptotic solutions if exist, or with results of analog calculations or predictions by other codes. The applied calculations include the estimation of ex-core detector response from neutron sources arranged in the core, and the estimation of in-core detector response.
Secondary neutron source modelling using MCNPX and ALEPH codes
Authors: Trakas Christos , Kerkar Nordine 
Published: June 2014

Monitoring the subcritical state and divergence of reactors requires the presence of neutron sources. But mainly secondary neutrons from these sources feed the ex-core detectors (SRD, Source Range Detector) whose counting rate is correlated with the level of the subcriticality of reactor.
In cycle 1, primary neutrons are provided by sources activated outside of the reactor (e.g. Cf252); part of this source can be used for the divergence of cycle 2 (not systematic). A second family of neutron sources is used for the second cycle: the spontaneous neutrons of actinides produced after irradiation of fuel in the first cycle. Both families of sources are not sufficient to efficiently monitor the divergence of the second cycles and following ones, in most reactors. Secondary sources cluster (SSC) fulfil this role. In the present case, the SSC [Sb, Be], after activation in the first cycle (production of Sb124, unstable), produces in subsequent cycles a photo-neutron source by gamma (from Sb124)-neutron (on Be9) reaction.
This paper presents the model of the process between irradiation in cycle 1 and cycle 2 results for SRD counting rate at the beginning of cycle 2, using the MCNPX code and the depletion chain ALEPH-V1 (coupling of MCNPX and ORIGEN codes). The results of this simulation are compared with two experimental results of the PWR 1450 MWe-N4 reactors. A good agreement is observed between these results and the simulations. The subcriticality of the reactors is about at -15,000 pcm. Discrepancies on the SRD counting rate between calculations and measurements are in the order of 10%, lower than the combined uncertainty of measurements and code simulation.
This comparison validates the AREVA methodology, which allows having an SRD counting rate best-estimate for cycles 2 and next ones and optimizing the position of the SSC, depending on the geographic location of sources, main parameter for optimal monitoring of subcritical states.
Benchmarking MCNP and TRIPOLI with PGNAA measurements
Authors: Carasco C. , Perot B. , Sikora A. , Mauerhofer E. , Havenith A. , Payan E. , Kettler J. , Kring T. , Ma J.L. 
Published: June 2014

The French Alternative Energies and Atomic Energy Commission (CEA Cadarache), the Forschungszentrum Jülich GmbH (FZJ), and the RWTH Aachen University (RWTH) are involved in a cooperation aiming at characterizing toxic and reactive elements in radioactive waste packages by means of Prompt Gamma Neutron Activation Analysis (PGNAA). The design of an optimized measurement system and the assessment of its performances for realistic scenarios can be conveniently studied by numerical Monte Carlo simulation, provided the model and nuclear data offer a sufficient precision.
Previous studies performed with MCNP have shown that when the nuclear data libraries lack of precision, relevant results can still be obtained by performing calculations in multiple steps (by first determining the radiative capture rate, and transporting the induced gamma toward the detector) and by injecting valid gamma-ray production data in-between [1]. In such cases, it is interesting to compare the results obtained with different codes. In the present paper, we propose to compare the MCNP and TRIPOLI codes with measurements obtained in MEDINA (Multi Element Detection based on Instrumental Neutron Activation), which is the new FZJ PGNAA facility [2]. The aim of the measurement campaign is to assess capture gamma rays of toxic elements that can be found in 200 L waste drums which are expected for geological repository.
Fast Monte Carlo Electron-Photon Transport Method and Application in Accurate Radiotherapy
Authors: Hao Lijuan , Sun Guangyao , Zheng Huaqing , Song Jing , Chen Zhenping , Li Gui ,   FDS Team
Published: June 2014

Monte Carlo (MC) method is the most accurate computational method for dose calculation, but its wide application on clinical accurate radiotherapy is hindered due to its poor speed of converging and long computation time. In the MC dose calculation research, the main task is to speed up computation while high precision is maintained.
The purpose of this paper is to enhance the calculation speed of MC method for electron-photon transport with high precision and ultimately to reduce the accurate radiotherapy dose calculation time based on normal computer to the level of several hours, which meets the requirement of clinical dose verification.
Based on the existing Super Monte Carlo Simulation Program (SuperMC), developed by FDS Team, a fast MC method for electron-photon coupled transport was presented with focus on two aspects: firstly, through simplifying and optimizing the physical model of the electron-photon transport, the calculation speed was increased with slightly reduction of calculation accuracy; secondly, using a variety of MC calculation acceleration methods, for example, taking use of obtained information in previous calculations to avoid repeat simulation of particles with identical history; applying proper variance reduction techniques to accelerate MC method convergence rate, etc.
The fast MC method was tested by a lot of simple physical models and clinical cases included nasopharyngeal carcinoma, peripheral lung tumor, cervical carcinoma, etc. The result shows that the fast MC method for electron-photon transport was fast enough to meet the requirement of clinical accurate radiotherapy dose verification. Later, the method will be applied to the Accurate/Advanced Radiation Therapy System ARTS as a MC dose verification module.
Maritime route of colonization of Europe
Authors: Paschou Peristera , Drineas Petros , Yannaki Evangelia , Razou Anna , Kanaki Katerina , Tsetsos Fotis , Padmanabhuni Shanmukha Sampath , Michalodimitrakis Manolis , Renda Maria C. , Pavlovic Sonja , Anagnostopoulos Achilles , Stamatoyannopoulos John A. , Kidd Kenneth K. , Stamatoyannopoulos George 
Published: June 2014

Significance
The question of colonization of Europe by Neolithic people of the Near East and their contribution to the farming economy of Europe has been addressed with extensive archaeological studies and many genetic investigations of extant European and Near Eastern populations. Here, we use DNA polymorphisms of extant populations to investigate the patterns of gene flow from the Near East to Europe. Our data support the hypothesis that Near Eastern migrants reached Europe from Anatolia. A maritime route and island hopping was mainly used by these Near Eastern migrants to reach Southern Europe.
Anthropogenic changes in sodium affect neural and muscle development in butterflies
Authors: Snell-Rood Emilie C. , Espeset Anne , Boser Christopher J. , White William A. , Smykalski Rhea 
Published: June 2014

Significance
Sodium is an essential micronutrient that is often limited in animal diets. It is important in the development of neural tissue and thought to have driven the evolution of specific foraging behavior. Human activity is drastically altering patterns of sodium availability, particularly through road salt application, but we know little about the consequences of such anthropogenic change on the development and evolution of wild animals. Here, we show that road salt runoff affects sodium concentrations of roadside plants, which in turn, have significant, (sometimes positive) effects on neural and muscular development of herbivores. These results suggest that anthropogenic changes in sodium can have major consequences for both behavioral development and selection on foraging behavior.
Self-assembly of amphiphilic Janus dendrimers into uniform onion-like dendrimersomes with predictable size and number of bilayers
Authors: Zhang Shaodong , Sun Hao-Jan , Hughes Andrew D. , Moussodia Ralph-Olivier , Bertin Annabelle , Chen Yingchao , Pochan Darrin J. , Heiney Paul A. , Klein Michael L. , Percec Virgil 
Published: June 2014

Significance
Simple injection of a solution of amphiphilic Janus dendrimer with specific primary structure into water or buffer has been shown to yield uniform submicrometer-size onion-like vesicles denoted dendrimersomes. The size and number of alternating internally confined bilayers is predicted by the final concentration of the Janus dendrimer. Onion-like dendrimersomes provide mimics of various biological membranes and can be elaborated to provide time-dependent delivery of drugs. Their ease of preparation contrasts with conventional methods used to make onion-like vesicles that are both complicated and time-consuming.
Social identification moderates the effect of crowd density on safety at the Hajj
Authors: Alnabulsi Hani , Drury John 
Published: June 2014

Significance
A large-scale survey of pilgrims on the Hajj to Mecca (also called Makkah) showed that where there is identification with the crowd the negative effect of crowd density on safety is diminished or even reversed: a new finding. The reason that identification with the crowd moderates the effect of density on safety is because crowd identification increases the perception that others will be supportive. This process also helps to explain national differences among pilgrims in feelings of safety during the event. In contrast both to engineering approaches, which neglect crowd psychology, and traditional crowd psychology, which assumes that the crowd is inherently a “problem,” this study shows how the crowd can be part of the solution in crowd safety management.
Marker for type VI secretion system effectors
Authors: Salomon Dor , Kinch Lisa N. , Trudgian David C. , Guo Xiaofeng , Klimko John A. , Grishin Nick V. , Mirzaei Hamid , Orth Kim 
Published: June 2014

Significance
The recently discovered type VI secretion system (T6SS) is used by Gram-negative bacteria to deliver effector proteins into both eukaryotic and prokaryotic neighboring cells to mediate virulence and competition, respectively. Even though several T6SS effector families have been described, many T6SSs are not associated with known effectors. In this work, we report the discovery of a conserved motif named MIX (marker for type six effectors) that is often located near the T6SS genome neighborhood and is found in numerous proteins from diverse Proteobacteria, among them several T6SS effectors. We show that the MIX motif can be used as a marker to identify new T6SS effectors, thereby significantly enlarging the list of known T6SS effector families.