bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity Analysis of Crack Shape on Screening Parameter in JSME FFS Rules for Nuclear Power Plants
Authors: Miura Naoki , Hojo Kiminobu
Published: October 2017

In the 2012 version of the JSME Fitness-for-Service Rules for Nuclear Power Plants, the procedure to calculate screening parameter, SC, which is used for selecting the analysis method (limit load controlled by plastic collapse, elastic-plastic fracture mechanics, or linear elastic fracture mechanics), has been revised to reflect a semi-elliptical surface crack. Both limit load solution and stress intensity factor solution are needed to calculate SC, and the solutions for a semi-elliptical surface crack are different from those for a fan-shape surface crack. In this study, the effect of the difference in crack shape on SC is investigated. Through the results on the sensitivity analysis, the adequacy of the evaluation procedure of SC is ascertained.
Discussions on Effects of Temperature in Fatigue Assessment of Stainless NPP Primary Piping
Authors: Solin Jussi , Curtit François , Blatman Géraud , Karabaki H. Ertugrul , Métais Thomas , Mayinger Wolfgang
Published: October 2017

Fatigue performance of Nuclear Power Plant (NPP) primary circuit components and laboratory specimens depends on temperature. Temperature plays a particular role in environmental fatigue, but affects also generic fatigue evaluations.

Historically, fatigue data was generated in air at room temperature using strain-control testing. For the purpose of engineering calculations, the strain was then transformed into “stress intensity”. The elastic-plastic strains were scaled to pseudo-stress units (psi or MPa) via the use of an elastic modulus. To make a single curve useable over a range of temperatures an adjusting factor was implemented in the codified stress analysis. The ratio of elastic modulus in the design and room temperatures was considered applicable to adjust the stress intensity (total strain) used in fatigue assessment.

Later on, temperature dependent factors were proposed for environmental effects {Fen = Nf(RT,air) / Nf(T,environment)}. Also environment independent temperature effects are covered by Fen factors, which are used to multiply fatigue usage. This means that temperature is supposed to be accounted for twice in fatigue assessments: first for stress intensity, then for allowable cycles. Moreover, fatigue data in high temperatures have been included in the data set behind the current design curve for stainless steels.

Incompatible corrections and code updates can lead to some over-conservatism when selecting adequate values for the elastic modulus and Fen for the fatigue calculations. Given the construction of the design curve as an integral part of the original codified assessment procedure, new developments in numerical stress analysis and experiments together with aim to perform calculations as consistent as possible with the physics at hand, a proposal is made in this paper to define a method to evaluate fatigue using strain amplitude rather than stress intensity amplitude.

A concern on double counting of temperature effects and inaccuracies in fatigue assessment was raised by the current authors [1] [2], but this issue has not yet been studied and discussed in depth. This paper will discuss effects of temperature in fatigue experiments and assessment in terms of transferability of laboratory data for fatigue assessment. Among others, a statistical study based on laboratory test results in Pressurized Water Reactor (PWR) environment will help identify possible gaps between the recorded fatigue lives and the values provided by the codified rules. The aim is to quantitatively analyze the ranges of inaccuracies and unknowns affecting fatigue assessment of NPP components in various operational temperatures.
Smart Technologies for Integrated Natural Risk Management: Innovative Methodologies and Remote Sensing
Authors: Marino Alessandra , Ciucci Mariano , Paolacci Fabrizio
Published: October 2017

Recent events outlined the relevance of the interactions between industrial and natural hazards (NaTech) particularly for what concerns seismic risk. EU regulation, namely Directive 2012/18/EU, explicitly requires risk analysis for NaTech events. The development of a risk assessment methodology for major hazard industrial plants allows the individuation of the critical elements of a plant in seismic-prone areas. The following implementation of smart technologies (sensors, actuators, innovative systems for seismic protection) to the critical elements allows for a relevant reduction of major hazards and related consequences.
Fracture Mechanics Analyses of Embedded Cracks Under PTS and Effects of Residual Stresses
Authors: Qian Guian , González-Albuixech V. F. , Niffenegger Markus
Published: October 2017

One potential challenge to the integrity of a reactor pressure vessel (RPV) of a pressurized water reactor is posed by a pressurized thermal shock (PTS), which is associated with severe cooling of the RPV followed by its repressurization. PTS transients lead to high tensile circumferential and axial stresses in the RPV wall. If the stress intensity factor (SIF) is large enough, a critical crack may grow. Thus, the RPV has to be assessed against cleavage fracture.

In this paper, two kinds of embedded cracks, i.e. semielliptical and elliptical crack with depth of 17 mm and length of 102 mm are considered. The extended finite element method (XFEM) is used to model such postulated cracks. The embedded crack with tip in the cladding/base interface causes a high KI. This is due to the stress discontinuities at the interface between the materials. In the FAVOR (probabilistic fracture mechanics code) calculation, for such cracks the closest point to the inner surface is calculated in order to be conservative. However, due to the highly ductile cladding material, it is unlikely for the embedded crack to propagate through the cladding. Thus, it is more appropriate to consider the outer surface point of the crack front.

The effect of welding residual stress and cladding/base interface residual stress on the crack driving force is studied. Surface cracks are assumed in the study of residual stresses. Results show that considering realistic welding residual stresses may increase KI by about 5 MPa·m0.5, while the cladding/base interface residual stress has a negligible effect on KI. The reason is that the cladding residual stress is only localized to the interface and it decreases significantly through the vessel wall.
Ultrasonic Inspection of Dissimilar Metal Welds for Probabilistic Reliability Assessment of Pipe Welds
Authors: Dugan Sandra , Jüngert Anne
Published: October 2017

There are several sources of uncertainties which need to be considered in a probabilistic reliability and lifetime assessment of safety-relevant components. In addition to the probabilistic distribution of material properties, the size and properties of flaws present in a component contribute to uncertainties in the lifetime analysis. In a current reactor safety research project, a methodology for a probabilistic fracture mechanics assessment of reliability for components with austenitic and dissimilar metal welds will be developed using the combined results from statistical evaluation of material properties and ultrasonic inspection (UT). Dissimilar metal welds present a particular challenge for ultrasonic testing due to the effects of the material anisotropy on ultrasonic propagation and scattering. Evaluation of inspection results is typically done using image-based techniques. As there is no simple relationship between UT response and flaw size, criteria for image evaluation and flaw sizing have to be defined taking into account the influence of various factors such as material and flaw properties on the UT response. In this paper, we present results from a study of the influence of grain structure on the ultrasonic inspection results and discuss the challenges of extracting data for probability of detection (POD) analyses.
Organization of the Independent Safety Review Done by Electrabel for the Safety Assessment of Doel 3 and Tihange 2 RPVs
Authors: Meert Arnaud , De Cock Jean-Paul
Published: October 2017

The paper will deal with the way Electrabel carried out an independent control of the safety case studies of Doel 3 and Tihange 2 Reactor Pressure Vessels assessments after the discovery of indications of hydrogen induced flakes.

Electrabel’s Physical Control Service (Service de Contrôle Physique: SCP), acting as an internal independent body, has been involved since the very beginning of the development of the Safety Case. Its objective has been to perform an independent review of the project deliverables issued by the Project Team.

Several independent evaluations were carried out. Some were externalised: for instance Sandia National Laboratories performed calculations with an independent methodology to challenge the project grouping methodology; they also assessed the UT technique used for the non-destructive tests. Others were done internally: for instance, statistical calculations were performed during the UT qualification process, leading to a recommendation to increase the detection level.

SCP also provided its recommendations when determining the fluence level for the irradiation campaigns done in the BR-2 reactor. This helped to challenge the correlations established for the Safety Case by the Project Team.

The paper will detail the way the SCP was organised, the scope of its activities and reviews. It will detail the legal process of independent review as requested by the Belgian legal framework. It will also detail some specific actions carried out as the Sandia counter-study and some external expertise performed.

During the whole assessment process, SCP produced several reports, synthetized in the final advise: ‘Report on independent analysis and advice regarding the Safety Case’ and its addendum, published on the website of the FANC. This late one covered the full project scope (Safety Case 2015 Version1), ranging from the preliminary studies, proceedings of mechanical tests, and draft documents up to the final justification file that was delivered to the Safety Authorities on 28 October 2015. An overview of those reports, the concerns and the solution found and finally the approbation of the action plan will be described.

Nevertheless, the paper will not address the part of the review done by the Regulatory Body and its Technical Support Organization as it is out of the scope of the SCP activities.
Penetration of Hydrogen Into Alpha-Fe: A Molecular Dynamics Study
Authors: Li Xiongying , Cui Tiancheng , Zhao Yongzhi , Zheng Jinyang , Xu Ping
Published: October 2017

Understanding of hydrogen penetration into α-Fe plays an important role in revealing the mechanism of hydrogen embrittlement in Fe-based alloys. This work aims to investigate the penetration process of hydrogen into α-Fe by molecular dynamics simulation method, including how hydrogen changes from molecular to atomic form and how hydrogen atoms enter into the sub-surface. Potential energy difference and atom density are calculated to describe the characteristics of H-Fe interactions and to analysis the invasion process. The simulation results provide an atomic-scale insight into the hydrogen invasion process.
A Novel Defect Location Method for Plate-Like Structure by Using Forward-Scattering Wave and Fuzzy C-Means Clustering
Authors: Chen Shaojie , Zhou Shaoping , Li Yong , Zhang Lanzhu
Published: October 2017

Ultrasonic guided wave technology combined with sparse transducer array provides an efficient and relatively cost-effective means of defect detection and monitoring for rapid interrogation of large in plate-like structures. However, imaging algorithm used baseline subtraction methods may be compromised under mismatched environment and operational conditions. A defect location method based on forward-scattering wave and fuzzy c-means clustering is proposed in this paper. The distance coefficient including location information between sensor pair using exciting and receiving signal and defect is defined to explain feasibility of the method proposed in this paper. A Parallel line array is evaluated using the method to locate defect. Experimental results show that the proposed method can effectively reduce the influence of mismatched environment and operational conditions on the defect location.
Comparison of Strip Yield and Net Section Plasticity Models for a Bar in Bending With a Single Edge Crack
Authors: Reinhardt Wolf , Metzger Don
Published: October 2017

The strip yield model is widely used to describe crack tip plasticity in front of a crack. In the strip yield model the stress in the plastic zone is considered as known, and stress and deformation fields can be obtained from elastic solutions using the condition that the crack tip stress singularity vanishes.

The strip yield model is generally regarded to be valid to describe small scale plasticity at a crack tip. The present paper examines the behavior of the strip yield model at the transition to large-scale plasticity and its relationship to net section plasticity descriptions. A bar in bending with a single edge crack is used as an illustrative example to derive solutions and compare with one-sided and two-sided plasticity solutions.
Load Monitoring and Condition Assessment of High-Pressure-High-Temperature (HPHT) Subsea Facilities
Authors: Shavandi Mohsen , Tang Fei
Published: October 2017

High Pressure - High Temperature (HPHT) design is a significant new challenge facing the subsea sector, particularly in the Gulf of Mexico. For fatigue-sensitive applications, the current regulations in the Gulf of Mexico will require operators to compare the actual load cycles experienced by the HPHT component to the load cycles used in the design verification analyses. Should the analyses show that the HPHT equipment is experiencing loading combinations that are greater than those anticipated in the original design, a new service life (loads, time in service, and cycles) based on the actual loads and cycles needs to be developed.

The condition assessment in other industries is mainly inspection-based, while inspection of subsea equipment at fatigue-sensitive locations during operation may not be practical. Thus, load monitoring and condition assessment of subsea facilities is a major challenge that the subsea industry is facing.

Several assessment methods were evaluated as part of this study, including use of available monitoring technologies in combination with analytical methods. The key findings are summarized to help establish the proper Load Monitoring Program (LMP) for HPHT subsea applications.
Containers for Commercial Spent Nuclear Fuel
Authors: Carter Joe T. , Jones Robert H.
Published: October 2017

An overview of containers for commercial SNF is provided. The presentation covers the current fleet of canisters, and their attributes, storage and transportation overpacks.
Swelling Characteristics of a Type 304SS Baffle Plate Irradiated up to 50 DPA in PWR and Validation of a Swelling Equation
Authors: Mogami Yuichi , Matsubara Toru , Yaguchi Seiji , Tsuda Tomohiro , Fujimoto Koji
Published: October 2017

When austenitic stainless steel is highly irradiated in a reactor under high temperature, voids will be created in the material, leading to volumetric expansion of structures. This phenomenon is known as void swelling. The deformation caused by the swelling possibly deteriorates the functionality of reactor internals in Pressurized Water Reactors (PWRs), especially baffle former assemblies. To evaluate the functionality of the internals against the swelling and to assure the structural integrity, simulation technologies play a key role, enabling the estimation of the swelling behavior of the internals through plant life. The simulation results strongly depend on inputs, especially on a swelling equation; however, it includes uncertainty to some extent because quite limited swelling data in PWR environment have been available, which are necessary for the validation of the equation.

To enable the validation of swelling equations and improve the reliability on the simulations, the authors investigated the swelling characteristics of a type 304SS baffle plate removed from a decommissioned PWR plant. A total of nine swelling data were obtained with the variety in neutron dose (33 to 47 dpa) and irradiation temperature (299 to 327°C). The swelling ratios obtained are ranging from 0.02 to 0.08%, which corresponds well with the swelling equation, showing the similar temperature dependency with the equation. Since the irradiation temperature range of the obtained data, up to 327°C, covers major part of baffle former assemblies, swelling ratios of most part of them are expected to be small, which is probably too small to harm the functionality of the assemblies. The results contribute to the better confidence on swelling simulations and to assure the integrity of PWR reactor internals.
Study on Safety of High Voltage GIS Busbars Shell
Authors: Yuan Shuxia , Zhou Sanping , Fan Yuguang
Published: October 2017

GIS, Gas Isolation Switchgears, is the closed combination of electrical appliances, which is filled with SF6 gas as a dielectric and insulation medium. The gas pressure is up to 0.5 MPa, so the GIS busbars shells are pressure vessels, which should have high reliability. Research about horizontal busbars shell showed that crack may appeared on the connection between the saddle support and the shell, then the gas leakage taken place. In this paper, the GIS busbars system in a certain substation is studied, the reaction force of the supports under the action of interior pressure, gravity, and temperature are calculated used as Autopipe. Then the stress distributions of the busbars shells are analyzed according to the supporting reaction force. At last, the safety of high voltage GIS busbars shell was analyzed.
Mechanical Properties of Dealloyed Aluminum Bronze Large-Bore Castings in Essential Cooling Water Service
Authors: Cipolla Russell C. , Garner Michael , Aldridge Arden J.
Published: October 2017

Metal loss caused by selective leaching of aluminum (referred to herein as dealloying) in certain aluminum-bronze (Al-Brz) alloys is an environmentally-induced degradation mechanism in piping systems containing cast components exposed to marine, brackish, or raw water service. Examples of this form of degradation have been observed in ASME Code Class 3 Essential Cooling Water systems. Mechanical properties for tensile strength and fracture toughness of Al-Brz static and centrifugal castings, fabricated to ASME SB-148 CA952 and CA954 specifications, can locally degrade in service due to dealloying under long exposure to aggressive water environments.

This paper presents the results on the reduction in mechanical strength as a result of dealloying. A mechanical testing program was completed where 20 tensile and 22 fracture toughness specimens were tested to determine the reduction in mechanical properties from no dealloying (virgin condition) to various amounts of dealloying up to 100% dealloyed condition measured across the specimen. The specimens were fabricated from components removed from service (some components being in service for over 25 years). The data were plotted as a function of percent dealloying where a systematic decrease in properties was seen directly dependent the amount of dealloyed material in the cross-section of the specimen.
Dynamic Cyclic Stress Analysis of Rolling of a Diametrically Loaded Helical Test Specimen
Authors: Metzger Don , Paulseth Mark , Gagnon Andre
Published: October 2017

In a particular nuclear application, separation between structural components is maintained by a helical spring such that the separating load bears across the diameter of the spring coils. Relative motion between the structural components due to changing load and temperature is accommodated by rolling of the spring. This rolling motion while under radial load results in cyclic loading of the spring material. Fatigue analysis of the cyclic loading must take into consideration the material degradation due to the unique operating environment, so testing of ex-service material is required. Standard fatigue test specimens are not possible due to the small dimensions of the spring component, so cyclic stress is applied to the material via a reciprocating rolling motion between two platens. Stress analysis of this arrangement provides the stress range and mean stress necessary for fatigue analysis. A three dimensional finite element dynamic simulation of the test process is applied to a nominal test specimen to determine detailed history of the stress distribution. Numerical challenges are addressed to ensure representative loading conditions are properly applied, and that steady-state response is achieved. Bounding stress ranges are determined, and the implications of the results in fatigue analysis are discussed. It is concluded that response at the ends of the specimens is important in properly evaluating test data.
Thermal Analysis of Girth Welded Joints of Dissimilar Metals in Pipes With Varying Clad Thicknesses
Authors: Kogo Bridget , Wang Bin , Wrobel Luiz , Chizari Mahmoud
Published: October 2017

Thermal analyses of girth welded joints of clads have been carried out using 2D and 3D finite element analysis (FEA) by using the engineering software Abaqus v.2016 (Dassault Systèmes). Transient temperature curves have been generated for different cladding thicknesses (of stainless steel and mild steel). The welding of the two dissimilar materials has been carried out in-house with the aid of a Tungsten Arc weld with dynamic measurement of the temperature profile in the vicinity areas of the welding track using high temperature thermocouples. Comparison of the measured temperature versus the simulation results shows close agreement.
Effect of Hydrogen on Fatigue-Crack Growth of a Ferritic-Pearlitic Low Carbon Steel
Authors: Nagao Akihide , Wang Shuai , Nygren Kelly E. , Dadfarnia Mohsen , Sofronis Petros , Robertson Ian M.
Published: October 2017

The effect of external high-pressure H2 gas on fatigue-crack growth behavior has been examined using a ferritic-pearlitic low carbon steel. The presence of hydrogen accelerates the crack growth rate by ≈13 times compared to the uncharged state and shifts the fracture surface morphology from ductile striations to a mixture of “flat” and “quasi-cleavage” features. The common feature found in the microstructure immediately beneath the hydrogen-induced fracture surface is enhanced plasticity in terms of refined dislocation cell structures and dense dislocation bands.
Material, Manufacturing and Test Results for High-Temperature Fiber-Reinforced Polymer Structures for NMR Reservoir Surveillance and Other Oilfield Applications
Authors: Mertiny Pierre , Bashar Mohammad , Yakimoski Todd , Hammami Ahmed
Published: October 2017

Nuclear magnetic resonance (NMR) logging provides a unique oilfield reservoir surveillance technique, which can distinguish formation fluid properties such as brine, gas, and oil saturation levels and oil viscosity. This open-hole technique is typically limited to applications below 150°C. For this purpose a high-temperature non-metallic and non-magnetic flask was required for the containment and insulation of the NMR logging equipment. Due to high-temperature operating conditions a fiber-reinforced bismaleimide (BMI) polymer material system was employed for the flask. Owing to its tubular shape, the filament winding manufacturing method was adopted for efficient flask production. The characteristics of the chosen BMI material system required elevated-temperature winding processes along with the integration of a liner structure coupled with an external coating layer to protect the composite structure from harmful fluid contact and ingress during reservoir surveillance operations. The present paper describes the development, manufacturing processes and testing campaign that were conducted to implement the BMI composite material system for the NMR containment flask and other advanced oilfield applications requiring non-metallic components.
Adsorption of film-forming species on NbO and NbO2 surfaces
Authors: Music Denis , Schmidt Paul , Mráz Stanislav
Published: October 2017

Based on a mass-energy analysis, Nb, NbO, NbO2, NbO3, O, O2, and O3 film forming-species occur in an Nb-O2-Ar sputtering plasma. H, H2, H2O, and OH also emerge due to high-vacuum conditions. Surface diffusion pathways for fast moving species (H, O, and OH) and adsorption energy are obtained by density functional theory. H rattles, O hops in a [110] direction, and OH moves in ⟨100⟩ channels on NbO(001), while surface diffusion on NbO2(001) is not species specific. There are strongly adsorbed species (Nb, O, O2, and O3) and weakly adsorbed species (Nb-O clusters and H containing molecules). H2O, O2, and O3 dissociate, while Nb-O clusters and OH undergo nondissociative adsorption and H2 is repelled. H incorporation is thus enabled via H and OH adsorption. Nb and O seem to promote an epitaxial growth of NbO, but not of NbO2. An NbO cluster on NbO(001) and an NbO2 cluster on NbO2(001) may sustain epitaxial growth. All other Nb-O clusters lead to a growth disruption or a nanostructure formation. In general, NbO can likely grow in a defect-free fashion, while this is not the case for NbO2 under kinetically limited growth conditions.
Review Article: Catalysts design and synthesis via selective atomic layer deposition
Authors: Cao Kun , Cai Jiaming , Liu Xiao , Chen Rong
Published: October 2017

Tailoring catalysts with atomic level control over active sites and composite structures is of great importance for advanced catalysis. This review focuses on the recent development of area selective atomic layer deposition (ALD) methods in composite catalysts design and synthesis. By adjusting and optimizing the area selective ALD processes, several catalytic structures are developed, including core shell structures, discontinuous overcoating structures, and embedded structures. The detailed synthesis strategies for these designed structures are reviewed, where the related selective approaches are highlighted and analyzed. In addition, the catalytic performance of such structures, including activity, selectivity, and stability, is discussed. Finally, a summary and outlook of area selective ALD for catalysts synthesis and applications is given.
Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics
Authors: Brogi F. , Malaspinas O. , Chopard B. , Bonadonna C.
Published: October 2017

The lattice Boltzmann method (LBM) is emerging as a powerful engineering tool for aeroacoustic computations. However, the LBM has been shown to present accuracy and stability issues in the medium-low Mach number range, which is of interest for aeroacoustic applications. Several solutions have been proposed but are often too computationally expensive, do not retain the simplicity and the advantages typical of the LBM, or are not described well enough to be usable by the community due to proprietary software policies. An original regularized collision operator is proposed, based on the expansion of Hermite polynomials, that greatly improves the accuracy and stability of the LBM without significantly altering its algorithm. The regularized LBM can be easily coupled with both non-reflective boundary conditions and a multi-level grid strategy, essential ingredients for aeroacoustic simulations. Excellent agreement was found between this approach and both experimental and numerical data on two different benchmarks: the laminar, unsteady flow past a 2D cylinder and the 3D turbulent jet. Finally, most of the aeroacoustic computations with LBM have been done with commercial software, while here the entire theoretical framework is implemented using an open source library (palabos).
A parametric model order reduction technique for poroelastic finite element models
Authors: Lappano Ettore , Polanz Markus , Desmet Wim , Mundo Domenico
Published: October 2017

This research presents a parametric model order reduction approach for vibro-acoustic problems in the frequency domain of systems containing poroelastic materials (PEM). The method is applied to the Finite Element (FE) discretization of the weak u–p integral formulation based on the Biot–Allard theory and makes use of reduced basis (RB) methods typically employed for parametric problems. The parametric reduction is obtained rewriting the Biot–Allard FE equations for poroelastic materials using an affine representation of the frequency (therefore allowing for RB methods) and projecting the frequency-dependent PEM system on a global reduced order basis generated with the proper orthogonal decomposition instead of standard modal approaches. This has proven to be better suited to describe the nonlinear frequency dependence and the strong coupling introduced by damping. The methodology presented is tested on two three-dimensional systems: in the first experiment, the surface impedance of a PEM layer sample is calculated and compared with results of the literature; in the second, the reduced order model of a multilayer system coupled to an air cavity is assessed and the results are compared to those of the reference FE model.
Development of ultrasound bioprobe for biological imaging
Authors: Shekhawat Gajendra S. , Dudek Steven M. , Dravid Vinayak P.
Published: October 2017

Imaging buried structures with ultrasound.
Meditation and yoga associated with changes in brain
Authors: Jarvis Michaela
Published: October 2017

Neuroscientists describe improvements in cognition and mood at AAAS event
Tunable porous nanoallotropes prepared by post-assembly etching of binary nanoparticle superlattices
Authors: Udayabhaskararao Thumu , Altantzis Thomas , Houben Lothar , Coronado-Puchau Marc , Langer Judith , Popovitz-Biro Ronit , Liz-Marzán Luis M. , Vuković Lela , Král Petr , Bals Sara , Klajn Rafal
Published: October 2017

Non–close-packed nanoparticle arrays

Films of colloidal nanoparticles usually form dense, close-packed lattices. If binary lattices could be made and one component removed, then a more open array could form, as long as the remaining nanoparticles could be stabilized. Udayabhaskararao
et al.
formed binary superlattices of gold and magnetite nanoparticles at an air-liquid interface that could then be transferred to carbon-coated surfaces (see the Perspective by Kotov). Selective etching of either of the nanoparticles created non–close-packed arrays with vacancies stabilized by the carbon surface.

Science
, this issue p.
514
; see also p.
448
Lysosomal metabolomics reveals V-ATPase- and mTOR-dependent regulation of amino acid efflux from lysosomes
Authors: Abu-Remaileh Monther , Wyant Gregory A. , Kim Choah , Laqtom Nouf N. , Abbasi Maria , Chan Sze Ham , Freinkman Elizaveta , Sabatini David M.
Published: October 2017

Regulated lysosomal efflux of amino acids

A new technique allows rapid purification of lysosomes and metabolic profiling by liquid chromatography and mass spectrometry. Abu-Remaileh
et al.
engineered cultured human cells to produce a protein tag on lysosomal membranes that could be used to rapidly precipitate purified lysosomes on magnetic beads. Analysis of their contents under various conditions showed that efflux from the lysosome of most essential amino acids (but not that of most other amino acids) is a regulated process. Amino acid transport was inhibited under conditions of nutrient depletion as a result of inhibition of the mTOR (mechanistic target of rapamycin) protein kinase complex.

Science
, this issue p.
807
What is consciousness, and could machines have it?
Authors: Dehaene Stanislas , Lau Hakwan , Kouider Sid
Published: October 2017

The controversial question of whether machines may ever be conscious must be based on a careful consideration of how consciousness arises in the only physical system that undoubtedly possesses it: the human brain. We suggest that the word “consciousness” conflates two different types of information-processing computations in the brain: the selection of information for global broadcasting, thus making it flexibly available for computation and report (C1, consciousness in the first sense), and the self-monitoring of those computations, leading to a subjective sense of certainty or error (C2, consciousness in the second sense). We argue that despite their recent successes, current machines are still mostly implementing computations that reflect unconscious processing (C0) in the human brain. We review the psychological and neural science of unconscious (C0) and conscious computations (C1 and C2) and outline how they may inspire novel machine architectures.
Comment on “The extent of forest in dryland biomes”
Authors: Schepaschenko Dmitry , Fritz Steffen , See Linda , Laso Bayas Juan Carlos , Lesiv Myroslava , Kraxner Florian , Obersteiner Michael
Published: October 2017

Bastin
et al
. (Reports, 12 May 2017, p. 635) claim to have discovered 467 million hectares of new dryland forest. We would argue that these additional areas are not completely “new” and that some have been reported before. A second shortcoming is that not all sources of uncertainty are considered; the uncertainty could be much higher than the reported value of 3.5%.
Assembling the brain from deep within
Authors: Donato Flavio
Published: October 2017

Stellate cells appear to drive the maturation of the entorhinal-hippocampal
network
Overriding sleep
Authors: Gradinaru Viviana
Published: October 2017

Neural substrates of wakefulness are probed with classic and emerging
technologies
Phenotypic diversity in autosomal-dominant cone-rod dystrophy elucidated by adaptive optics retinal imaging
Authors: Song Hongxin , Rossi Ethan A , Stone Edwin , Latchney Lisa , Williams David , Dubra Alfredo , Chung Mina
Published: October 2017

Purpose

Several genes causing autosomal-dominant cone-rod dystrophy (AD-CRD) have been identified. However, the mechanisms by which genetic mutations lead to cellular loss in human disease remain poorly understood. Here we combine genotyping with high-resolution adaptive optics retinal imaging to elucidate the retinal phenotype at a cellular level in patients with AD-CRD harbouring a defect in the GUCA1A gene.

Methods

Nine affected members of a four-generation AD-CRD pedigree and three unaffected first-degree relatives underwent clinical examinations including visual acuity, fundus examination, Goldmann perimetry, spectral domain optical coherence tomography and electroretinography. Genome-wide scan followed by bidirectional sequencing was performed on all affected participants. High-resolution imaging using a custom adaptive optics scanning light ophthalmoscope (AOSLO) was performed for selected participants.

Results

Clinical evaluations showed a range of disease severity from normal fundus appearance in teenaged patients to pronounced macular atrophy in older patients. Molecular genetic testing showed a mutation in in GUCA1A segregating with disease. AOSLO imaging revealed that of the two teenage patients with mild disease, one had severe disruption of the photoreceptor mosaic while the other had a normal cone mosaic.

Conclusions

AOSLO imaging demonstrated variability in the pattern of cone and rod cell loss between two teenage cousins with early AD-CRD, who had similar clinical features and had the identical disease-causing mutation in GUCA1A. This finding suggests that a mutation in GUCA1A does not lead to the same degree of AD-CRD in all patients. Modifying factors may mitigate or augment disease severity, leading to different retinal cellular phenotypes.
Outcomes following polypectomy for malignant colorectal polyps are similar to those following surgery in the general population
Authors: Lopez Anthony , Bouvier Anne-Marie , Jooste Valérie , Cottet Vanessa , Romain Gaëlle , Faivre Jean , Manfredi Sylvain , Lepage Come
Published: October 2017

Objective

Population-based studies on colorectal malignant polyps (MPs) are scarce. The aim of this study was to describe time trends in the incidence of colorectal MPs before and after the introduction of a colorectal mass-screening programmein 2003 and to assess outcomes (survival and recurrence) after endoscopic or surgical resection in patients with MPs.

Design

We included 411 patients with MPs diagnosed between 1982 and 2011 in a well-defined population. Age-standardised incidence rates were calculated. Univariate and multivariate 5-year recurrence and net survival analyses were performed according to gross morphology.

Results

Age-standardised incidence of MPs in patients aged 50–74 years doubled from 5.4 in 1982–2002 to 10.9 per 100 000 in 2003–2011. Pedunculated MPs were more frequently resected endoscopically (38.2%) than were sessile MPs (19.1%; p<0.001). For patients with pedunculated MPs and a pathological margin ≥1 mm, the 5 -year cumulative recurrence rate did not differ significantly between surgical and endoscopic resection (8.2% and 2.4%, respectively). For patients with sessile MPs, it was 3.0% after firs

t-line or second-line surgical resection, 8.6% after endoscopic resection and 17.9% after transanal resection (p=0.016). The recurrence rate decreased dramatically for patients with sessile MPs from 11.3% (1982–2002) to 1.2% (2003–2009) (p=0.010) and remained stable for pedunculated MPs at 4.6% and 6.7%, respectively. Five-year net survival was 81.0% when pathological margins were <1 mm and 95.6% when ≥1 mm (p=0.024).

Conclusion

Outcomes following polypectomy in patients with a pathological margin ≥1 mm are similar to those following surgery in the general population. Endoscopic resection needs to be completed by surgery if pathological margins are less than 1 mm.
Adipose tissue macrophages induce hepatic neutrophil recruitment and macrophage accumulation in mice
Authors: Bijnen Mitchell , Josefs Tatjana , Cuijpers Ilona , Maalsen Constantijn J , van de Gaar José , Vroomen Maria , Wijnands Erwin , Rensen Sander S , Greve Jan Willem M , Hofker Marten H , Biessen Erik A L , Stehouwer Coen D A , Schalkwijk Casper G , Wouters Kristiaan
Published: October 2017

Objective

Obesity is a risk factor for non-alcoholic steatohepatitis (NASH). This risk has been attributed to visceral adipose tissue (vAT) expansion associated with increased proinflammatory mediators. Accumulation of CD11c+ proinflammatory adipose tissue macrophages (ATM) is an important driver of vAT inflammation. We investigated the role of ATMs in hepatic inflammation during NASH development.

Design

vAT isolated from lean, obese or ATM-depleted (using clodronate liposomes) obese mice was transplanted to lean ldlr-/- acceptor mice. Systemic and hepatic inflammation was assessed either after 2 weeks on standard chow or after 8 weeks on high cholesterol diet (HCD) to induce NASH.

Results

Transplanting donor vAT from obese mice increased HCD-induced hepatic macrophage content compared with lean-transplanted mice, worsening liver damage. ATM depletion prior to vAT transplantation reduced this increased hepatic macrophage accumulation. On chow, vAT transplantation induced a more pronounced increase in circulating and hepatic neutrophil numbers in obese-transplanted than lean-transplanted mice, while ATM depletion prior to vAT transplantation reversed this effect. Microarray analysis of fluorescence-activated cell sorting of CD11c+ and CD11c− macrophages isolated from donor adipose tissue showed that obesity resulted in enhanced expression of neutrophil chemotaxis genes specifically in CD11c+ ATMs. Involvement of the neutrophil chemotaxis proteins, CXCL14 and CXCL16, was confirmed by culturing vAT. In humans, CD11c expression in vAT of obese individuals correlated with vAT expression of neutrophil chemotactic genes and with hepatic expression of neutrophil and macrophage marker genes.

Conclusion

ATMs from obese vAT induce hepatic macrophage accumulation during NASH development, possibly by enhancing neutrophil recruitment.
Assessment of the incorporation of CNV surveillance into gene panel next-generation sequencing testing for inherited retinal diseases
Authors: Ellingford Jamie M , Horn Bradley , Campbell Christopher , Arno Gavin , Barton Stephanie , Tate Catriona , Bhaskar Sanjeev , Sergouniotis Panagiotis I , Taylor Rachel L , Carss Keren J , Raymond Lucy F L , Michaelides Michel , Ramsden Simon C , Webster Andrew R , Black Graeme C M
Published: October 2017

Background

Diagnostic use of gene panel next-generation sequencing (NGS) techniques is commonplace for individuals with inherited retinal dystrophies (IRDs), a highly genetically heterogeneous group of disorders. However, these techniques have often failed to capture the complete spectrum of genomic variation causing IRD, including CNVs. This study assessed the applicability of introducing CNV surveillance into first-tier diagnostic gene panel NGS services for IRD.

Methods

Three read-depth algorithms were applied to gene panel NGS data sets for 550 referred individuals, and informatics strategies used for quality assurance and CNV filtering. CNV events were confirmed and reported to referring clinicians through an accredited diagnostic laboratory.

Results

We confirmed the presence of 33 deletions and 11 duplications, determining these findings to contribute to the confirmed or provisional molecular diagnosis of IRD for 25 individuals. We show that at least 7% of individuals referred for diagnostic testing for IRD have a CNV within genes relevant to their clinical diagnosis, and determined a positive predictive value of 79% for the employed CNV filtering techniques.

Conclusion

Incorporation of CNV analysis increases diagnostic yield of gene panel NGS diagnostic tests for IRD, increases clarity in diagnostic reporting and expands the spectrum of known disease-causing mutations.
Associations between emphysema-like lung on CT and incident airflow limitation: a general population-based cohort study
Authors: Oelsner Elizabeth C , Smith Benjamin M , Hoffman Eric A , Folsom Aaron R , Kawut Steven M , Kaufman Joel D , Manichaikul Ani , Lederer David J , Schwartz Joseph E , Watson Karol E , Enright Paul L , Austin John H M , Lima Joao A C , Shea Steven J , Barr Robert G
Published: October 2017

Emphysema on CT is associated with accelerated lung function decline in heavy smokers and patients with COPD; however, in the general population, it is not known whether greater emphysema-like lung on CT is associated with incident COPD. We used data from 2045 adult participants without initial prebronchodilator airflow limitation, classified by FEV1/FVC<0.70, in the Multi-Ethnic Study of Atherosclerosis. Emphysema-like lung on baseline cardiac CT, defined as per cent low attenuation areas<—950HU>upper limit of normal, was associated with increased odds of incident airflow limitation at 5-year follow-up on both prebronchodilator (adjusted OR 2.62, 95% CI 1.47 to 4.67) and postbronchodilator (adjusted OR 4.38, 95% CI 1.63 to 11.74) spirometry, independent of smoking history. These results support investigation into whether emphysema-like lung could be informative for COPD risk stratification.
Equine infectious anaemia in Europe: an ongoing threat to the UK
Authors: Roberts Helen
Published: October 2017

Helen Roberts of Defra's International Disease Monitoring team sets out the situation regarding equine infectious anaemia in Europe, the threat to the UK and the expectations of disease control measures in light of an outbreak being detected.
Energy expenditure during an exercise training session for cardiac patients
Authors: Santa-Clara Helena , Melo Xavier , Willi Romina , Pinto Rita , Santos Vanessa , Almeida José P. , Martins Rodrigo , Clijsen Ron , Mendes Miguel , Fernhall Bo
Published: October 2017

Increasing energy expenditure (EE) in cardiac patients remains a challenge. Exercise approaches in cardiac rehabilitation/secondary prevention programs (CR/SP) have consistently resulted in minimal weight loss, due in part to the low exercise-related EE. The purpose of this study was to measure the EE among patients participating in a routine exercise session of Phase III maintenance CR/SP, where a recreational activity was introduced. Twelve overweight/obese male patients with coronary artery disease (aged 62.6 ± 8.5 years) had their total EE measured during a combined aerobic (circuit workout (ACW) and recreational activity) and resistance training (RT) session using a portable gas analyzer. Subjects were instructed to exercise at 60%–70% of heart rate reserve. Activity EE was calculated from total EE and resting EE. The duration of the session was 75.3 ± 1.5 min, of which 59.7 ± 8.8 min were above moderate intensity (3–6 METs). Activity EE was 309 ± 76 kcal, concurring to a total EE of 457 ± 80 kcal (3.9 ± 0.8 METs-h). ACW, recreational activity, and RT fulfilled 34.4% ± 6.4%, 25.0% ± 5.3%, and 14.2% ± 2.7% of the activity EE, respectively. Absolute intensities (METs) were significantly different between the RT (3.9 ± 1.0) and the ACW (6.9 ± 1.8) and recreational activity (5.9 ± 0.8). In conclusion, a combined aerobic and resistance training following standard exercise prescription practices, coupled with a recreational activity, is an effective tool to promote exercise above moderate intensity in male coronary artery disease patients. Clinicians can adopt concepts from recreational activity to develop CR/SP sessions.
Change in resting position in dairy calves during the first weeks of life
Authors: Pucora Endre , Clauss Marcus
Published: October 2017

Rumination relies on a gravity gradient, thus, adult ruminants only use sternal recumbency; neonates, however, also use lateral recumbency. Seventy-eight calves were observed to track the shift from variable recumbent positions to exclusive sternal recumbency, which occurred by 16 wk of age, paralleling reports on the development of proper rumination.
Spring phenological adaptation of blue honeysuckle (Lonicera caerulea L.) foundation germplasm in a temperate climate
Authors: Gerbrandt Eric M. , Bors Robert H. , Chibbar Ravindra N. , Baumann Thomas E.
Published: October 2017

Blue honeysuckle (Lonicera caerulea L.) is a novel fruit crop that stands out for its northern climatic adaptation. Understanding spring phenological adaptation to temperate climate is central to development of a broader range of production and greater mainstream crop potential. In 2012 and 2013 across three sites in the Fraser Valley, British Columbia, spring phenophases from bud break to fruit harvest were determined across three foundation groups. Genetic variability is characterized for Russian, Japanese, and Kuril blue honeysuckle foundation groups used in breeding at the University of Saskatchewan, Saskatoon, SK. Germplasm group membership is the principal feature of phenological adaptation. Although temperate climate adaptation is limited in the Russian germplasm, the intermediate Japanese and later Kuril spring phenology provide an adequate degree of temperate climate adaptation to facilitate commercial production. These findings demonstrate that blue honeysuckle has phenological adaptation to a temperate climate. Diversity between and within genetic groups presents opportunities for crop enhancement, especially through breeding for later bloom periods.