bluuebunny/crossref_metadata_2025 huggingface dataset:
First-principles study on electronic, optic, elastic, dynamic and thermodynamic properties of RbH compound
Authors: Gulebaglan Sinem Erden , Dogan Emel Kilit , Secuk Mehmet Nurullah , Aycibin Murat , Erdinc Bahattin , Akkus Harun
Published: December 2015

We performed first-principles calculations to obtain the electronic, optical, elastic, lattice-dynamical and thermodynamic properties of RbH compound with rock salt structure. The ground-state properties, i.e., the lattice constant and the band gap were investigated using a plane wave pseudopotential method within density functional theory. The calculated lattice constant, bulk modulus, energy band gap and elastic constants are reported and compared with previous theoretical and experimental results. Our calculated results and the previous results which are obtained from literature are in a good agreement. Moreover, real and imaginary parts of complex dielectric function, reflectivity spectrum, absorption, extinction coefficient and loss function as a function of photon energy and refractive index with respect to photon wavelength were calculated. In addition, temperature dependent thermodynamic properties such as Helmholtz free energy, internal energy, entropy and specific heat have been studied.
Trendanalyse der Qualitätsindikatoren der Krankenhäuser einer Region von 2006/07 bis 2013
Authors: Held J. , Lack N. , Hermanek P. , Eßer M.
Published: December 2015

Einleitung: Trotz bundesweiter Einführung von Qualitätsindikatoren (QI) in der stationären externen Qualitätssicherung fehlt eine systematische Evaluation ihrer Entwicklung im Zeitverlauf.

Methode: Es wurde eine Trendanalyse der jährlich von 2006/7 bis 2013 erhobenen Gesamtraten von QI bayerischer Krankenhäuser durchgeführt. 123 von insgesamt 245 Indikatoren aus 15 Leistungsbereichen waren über den gesamten Zeitraum verfügbar und vergleichbar. Deren Gesamtraten wurden mittels Joinpoint Regressionen im zeitlichen Verlauf dargestellt. Klinikraten wurden exemplarisch für einen Leistungsbereich mit Boxplots analysiert.

Ergebnis: 99 QI (80,5%) zeigten einen positiven Trend, 67 davon (54,5% aller QI) einen statistisch signifikanten. Ein Wechsel von positivem zu negativem Trend war bei 15 QI (12,2%) festzustellen, wobei der negative Trend nur in einem Fall signifikant war. 9 QI (7,3%) wiesen einen kontinuierlich negativen Trend auf (3 davon signifikant). Die Boxplots der Klinikraten zeigen eine über die Jahre konstante Anzahl Kliniken, deren Ergebnisse weit unterhalb des bayernweiten Durchschnitts liegen.

Schlussfolgerungen: Der überwiegend positive Trend der Indikatoren könnte als Hinweis für die Wirksamkeit des Verfahrens der externen Qualitätssicherung gewertet werden und weiteren qualitätsverbessernden Maßnahmen Auftrieb geben.
Vergleich gesundheitsrelevanter Verhaltensmuster von Jungen und Mädchen in Deutschland: Ergebnisse der MoMo Studie
Authors: Spengler S. , Mess F. , Woll A.
Published: December 2015

Ziel der Studie: Um die Gesundheit von Jugendlichen optimal fördern zu können ist es wichtig, typische jugendliche Verhaltensmuster zu kennen. Ziel der vorliegenden Untersuchung war es, geschlechtsspezifische gesundheitsrelevante Verhaltensmuster von Jugendlichen in Deutschland zu identifizieren und zu vergleichen.

Methodik: Im Rahmen des KiGGS Surveys und der MoMo Studie wurden 832 Jungen und 811 Mädchen (11–17 Jahre) zum Gesundheitsverhalten befragt. Mit den Indices Aktivitätslevel, Ernährungsqualität und Medienkonsum wurden Clusteranalysen für Jungen und Mädchen getrennt durchgeführt.

Ergebnisse: Für beide Geschlechter konnten jeweils 4 Gesundheitsverhaltensmuster identifiziert werden, die sich hinsichtlich ihrer Ausprägungen ähneln, sich jedoch in Bezug auf Clustergröße, Ausprägungsstärke der Verhaltensweisen und Korrelate unterscheiden: Mädchen haben seltener ein sportorientiertes Verhaltensmuster als Jungen, Aktivitätslevel und Medienkonsum sind insgesamt bei den Verhaltensmustern der Mädchen schwächer ausgeprägt. Die Verhaltensmuster der Mädchen sind stärker als die der Jungen mit dem sozialen Status assoziiert, bei Jungen unterscheidet sich die Übergewichtsprävalenz je nach Verhaltensmuster signifikant.

Schlussfolgerungen: Die ähnlichen Clusterlösungen unterstützen die Annahme, dass stabile typische Gesundheitsverhaltensmuster bei deutschen Jugendlichen existieren, was die Auswahl von homogenen Zielgruppen für Lebensstilinterventionen erleichtert. Die Unterschiede zwischen Jungen und Mädchen verweisen darauf, dass Gesundheitsförderprogramme geschlechtsabhängig unterschiedliche Schwerpunkte verfolgen sollten.
X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics
Authors: Rácz R. , Biri S. , Pálinkás J. , Mascali D. , Castro G. , Caliri C. , Romano F. P. , Gammino S.
Published: December 2015

Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.
Infrared laser induced population transfer and parity selection in 14NH3: A proof of principle experiment towards detecting parity violation in chiral molecules
Authors: Dietiker P. , Miloglyadov E. , Quack M. , Schneider A. , Seyfang G.
Published: December 2015

We have set up an experiment for the efficient population transfer by a sequential two photon—absorption and stimulated emission—process in a molecular beam to prepare quantum states of well defined parity and their subsequent sensitive detection. This provides a proof of principle for an experiment which would allow for parity selection and measurement of the time evolution of parity in chiral molecules, resulting in a measurement of the parity violating energy difference ΔpvE between enantiomers of chiral molecules. Here, we present first results on a simple achiral molecule demonstrating efficient population transfer (about 80% on the average for each step) and unperturbed persistence of a selected excited parity level over flight times of about 1.3 ms in the beam. In agreement with model calculations with and without including nuclear hyperfine structure, efficient population transfer can be achieved by a rather simple implementation of the rapid adiabatic passage method of Reuss and coworkers and considering also the stimulated Raman adiabatic passage technique of Bergmann and coworkers as an alternative. The preparation step uses two powerful single mode continuous wave optical parametric oscillators of high frequency stability and accuracy. The detection uses a sensitive resonantly enhanced multiphoton ionization method after free flight lengths of up to 0.8 m in the molecular beam. Using this technique, we were able to also resolve the nuclear hyperfine structure in the rovibrational levels of the ν1 and ν3 fundamentals as well as the 2ν4 overtone of 14NH3, for which no previous data with hyperfine resolution were available. We present our new results on the quadrupole coupling constants for the ν1, ν3, and 2ν4 levels in the context of previously known data for ν2 and its overtone, as well as ν4, and the ground state. Thus, now, 14N quadrupole coupling constants for all fundamentals and some overtones of 14NH3 are known and can be used for further theoretical analysis.
Very large strain gauges based on single layer MoSe2 and WSe2 for sensing applications
Authors: Hosseini Manouchehr , Elahi Mohammad , Pourfath Mahdi , Esseni David
Published: December 2015

Here, we propose a strain gauge based on single-layer MoSe2 and WSe2 and show that, in these materials, the strain induced modulation of inter-valley phonon scattering leads to large mobility changes, which in turn result in highly sensitive strain gauges. By employing density-functional theory bandstructure calculations, comprehensive scattering models, and the linearized Boltzmann equation, we explain the physical mechanisms for the high sensitivity to strain of the resistivity in single-layer MoSe2 and WSe2, discuss the reduction of the gauge factor produced by extrinsic scattering sources (e.g., chemical impurities), and propose ways to mitigate such sensitivity degradation.
Polymer-based solar cells having an active area of 1.6 cm2 fabricated via spray coating
Authors: Scarratt N. W. , Griffin J. , Wang T. , Zhang Y. , Yi H. , Iraqi A. , Lidzey D. G.
Published: December 2015

We demonstrate the fabrication of polymer solar cells in which both a PEDOT:PSS hole transport and a PCDTBT:PC71BM photoactive layer are deposited by spray-casting. Two device geometries are explored, with devices having a pixel area of 165 mm2 attaining a power conversion efficiency of 3.7%. Surface metrology indicates that the PEDOT:PSS and PCDTBT:PC71BM layers have a roughness of 2.57 nm and 1.18 nm over an area of 100 μm2. Light beam induced current mapping reveals fluctuations in current generation efficiency over length-scales of ∼2 mm, with the average photocurrent being 75% of its maximum value.
Glucans monomer-exchange dynamics as an open chemical network
Authors: Rao Riccardo , Lacoste David , Esposito Massimiliano
Published: December 2015

We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming some of the polymer concentrations fixed (chemostatting). We show that three different long-time behaviors may ensue: equilibrium states, nonequilibrium steady states, and continuous growth states. We dynamically and thermodynamically characterize these states and emphasize the crucial role of conservation laws in identifying the chemostatting conditions inducing them.
Enhanced magnetization at the Cr/MgO(001) interface
Authors: Leroy M.-A. , Bataille A. M. , Wang Q. , Fitzsimmons M. R. , Bertran F. , Le Fèvre P. , Taleb-Ibrahimi A. , Vlad A. , Coati A. , Garreau Y. , Hauet T. , Gatel C. , Ott F. , Andrieu S.
Published: December 2015

We report on the magnetization at the Cr/MgO interface, which we studied through two complementary techniques: angle-resolved photoemission spectroscopy and polarized neutron reflectivity. We experimentally observe an enhanced interface magnetization at the interface, yet with values much smaller than the ones reported so far by theoretical and experimental studies on Cr(001) surfaces. Our findings cast some doubts on the interpretations on previous works and could be useful in antiferromagnetic spin torque studies.
Impact of x-ray dose on track formation and data analysis for CR-39-based proton diagnostics
Authors: Rinderknecht H. G. , Rojas-Herrera J. , Zylstra A. B. , Frenje J. A. , Gatu Johnson M. , Sio H. , Sinenian N. , Rosenberg M. J. , Li C. K. , Séguin F. H. , Petrasso R. D. , Filkins T. , Steidle Jeffrey A. , Steidle Jessica A. , Traynor N. , Freeman C.
Published: December 2015

The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1–100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5–9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The impact of this effect on the analysis of data from existing CR-39-based proton diagnostics on OMEGA and the National Ignition Facility is evaluated and best practices are proposed for cases in which the effect of x rays is significant.
A one-stage, high-load capacity separation actuator using anti-friction rollers and redundant shape memory alloy wires
Authors: Xiaojun Yan , Dawei Huang , Xiaoyong Zhang , Ying Liu , Qiaolong Yang
Published: December 2015

This paper proposes a SMA (shape memory alloy) wire-based separation actuator with high-load capacity and simple structure. The novel actuator is based on a one-stage locking mechanism, which means that the separation is directly driven by the SMA wire. To release a large preload, a group of anti-friction rollers are adopted to reduce the force for triggering. In addition, two SMA wires are used redundantly to ensure a high reliability. After separation, the actuator can be reset automatically without any auxiliary tool or manual operation. Three prototypes of the separation actuator are fabricated and tested. According to the performance test results, the actuator can release a maximum preload of 40 kN. The separation time tends to decrease as the operation current increases and it can be as short as 0.5 s under a 7.5 A (the voltage is 5.8 V) current. Lifetime test indicates that the actuator has a lifetime of more than 50 cycles. The environmental tests demonstrate that the actuator can endure the typical thermal and vibration environment tests without unexpected separation or structure damage, and separate normally after these environment tests.
A stochastic simulation method for the assessment of resistive random access memory retention reliability
Authors: Berco Dan , Tseng Tseung-Yuen
Published: December 2015

This study presents an evaluation method for resistive random access memory retention reliability based on the Metropolis Monte Carlo algorithm and Gibbs free energy. The method, which does not rely on a time evolution, provides an extremely efficient way to compare the relative retention properties of metal-insulator-metal structures. It requires a small number of iterations and may be used for statistical analysis. The presented approach is used to compare the relative robustness of a single layer ZrO2 device with a double layer ZnO/ZrO2 one, and obtain results which are in good agreement with experimental data.
An efficient reconstruction algorithm for differential phase-contrast tomographic images from a limited number of views
Authors: Sunaguchi Naoki , Yuasa Tetsuya , Gupta Rajiv , Ando Masami
Published: December 2015

The main focus of this paper is reconstruction of tomographic phase-contrast image from a set of projections. We propose an efficient reconstruction algorithm for differential phase-contrast computed tomography that can considerably reduce the number of projections required for reconstruction. The key result underlying this research is a projection theorem that states that the second derivative of the projection set is linearly related to the Laplacian of the tomographic image. The proposed algorithm first reconstructs the Laplacian image of the phase-shift distribution from the second-derivative of the projections using total variation regularization. The second step is to obtain the phase-shift distribution by solving a Poisson equation whose source is the Laplacian image previously reconstructed under the Dirichlet condition. We demonstrate the efficacy of this algorithm using both synthetically generated simulation data and projection data acquired experimentally at a synchrotron. The experimental phase data were acquired from a human coronary artery specimen using dark-field-imaging optics pioneered by our group. Our results demonstrate that the proposed algorithm can reduce the number of projections to approximately 33% as compared with the conventional filtered backprojection method, without any detrimental effect on the image quality.
Study on Australian energy policy, socio-economic, and environment issues
Authors: Azad A. K. , Rasul M. G. , Khan M. M. K. , Sharma Subhash C. , Bhuiya M. M. K.
Published: December 2015

This article deals with the Australian total energy consumption related to economic growth and carbon dioxide (CO2) emission in which total energy consumption is sub-divided into renewable and non-renewable energy consumption. The aim of this study is to determine the nexus between all energy elements with gross domestic product and CO2 emission using the Cobb-Douglas equation. The study is based on the Australian panel data over the period from 1976–1977 to 2012–2013. Vector error correction model and generalized method of moments were used to estimate the variables for the relationship between energy variables. The proposed model shows good agreement with the data available on the bioenergy production and consumption in Organization for Economic Co-operation and Development countries. In this model, oil price, oil consumption, carbon tax, renewable energy technology, population growth, urbanization, etc., have been considered as model variables or governing factors. The results show the bidirectional relationship between energy consumption, economic growth, and CO2 emission. The proposed energy economic model is focused on resilient strategic investment decisions on CO2 emission intensive sectors like electricity generation and the transport sector. The model can be used to determine and understand the relationship between reduction of CO2 emission and economic growth in Australia.
Schottky source/drain germanium-based metal-oxide-semiconductor field-effect transistors with self-aligned NiGe/Ge junction and aggressively scaled high-k gate stack
Authors: Hosoi Takuji , Minoura Yuya , Asahara Ryohei , Oka Hiroshi , Shimura Takayoshi , Watanabe Heiji
Published: December 2015

Schottky source/drain (S/D) Ge-based metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated by combining high permittivity (high-k) gate stacks with ultrathin AlOx interlayers and Fermi level depinning process by means of phosphorous ion implantation into NiGe/Ge contacts. Improved thermal stability of the metal/high-k/Ge stacks enabled self-aligned integration scheme for Schottky S/D complementary MOS applications. Significantly reduced parasitic resistance and aggressively scaled high-k gate stacks with sub-1-nm equivalent oxide thickness were demonstrated for both p- and n-channel Schottky Ge-FETs with the proposed combined technology.
Resistance-switching mechanism of SiO2:Pt-based Mott memory
Authors: Zhang Keke , Lu Nianduan , Li Ling , Liu Qi , Liu Ming
Published: December 2015

We proposed a basic resistance-switching mechanism for Mott memory based on the SiO2:Pt system to explain why device performance depends on the electrode. The competition between collection current and drift current in SiO2:Pt system was attributed to the polarity of the set voltage depending on the work function of the electrode. The proposed theory, based on the energy band of SiO2:Pt calculated using first-principles calculations, explains the perplexing phenomenon wherein a SiO2:Pt device cannot show reproducible resistance-switching behavior with a symmetric electrode. The theoretical set voltage agrees with prior experimental results, which verifies our theory.
Electric field triggering the spin reorientation and controlling the absorption and release of heat in the induced multiferroic compound EuTiO3
Authors: von Ranke P. J. , Gama S. , Ribeiro P. O. , Carvalho A. Magnus G. , Alho B. P. , Alvarenga T. S. T. , Nobrega E. P. , Caldas A. , de Sousa V. S. R. , Lopes P. H. O. , de Oliveira N. A.
Published: December 2015

We report remarkable results due to the coupling between the magnetization and the electric field induced polarization in EuTiO3. Using a microscopic model Hamiltonian to describe the three coupled sublattices, Eu-(spin-up), Eu-(spin-down), and Ti-(moment), the spin flop and spin reorientation phase transitions were described with and without the electric-magnetic coupling interaction. The external electric field can be used to tune the temperature of the spin reorientation phase transition TSR = TSR(E). When the TSR is tuned around the EuTiO3—Néel temperature (TN = 5.5 K), an outstanding effect emerges in which EuTiO3 releases heat under magnetic field change. The electric field controlling the spin reorientation transition and the endo-exothermic processes are discussed through the microscopic interactions model parameters.
Atomic-scale microstructure underneath nanoindentation in Al-Cr-N ceramic films
Authors: Zhuang Chunqiang , Li Zhipeng , Lin Songsheng
Published: December 2015

In this work, Al-Cr-N ceramic films deformed by nanoindentation were peeled off from silicon substrates and their atomic-scale microstructures underneath the indenter were investigated by high resolution transmission electron microscope (HR-TEM). Dislocations were formed underneath the indenter and they accumulated along nano-grain boundaries. The accumulative dislocations triggered the crack initiation along grain boundaries, and further resulted in the crack propagation. Dislocations were also observed in nano-grains on the lateral contact area. A model was proposed to describe the variation of microstructures under nanoindentation.
Climate change impacts and adaptation in agricultural water management in the Philippines.
Authors: Lansigan F. P. , Cruz A. C. dela
Published: December 2015

Climate change is now a reality and is expected to have profound impacts on agricultural production systems, thus threatening food security. Local observational evidence of changing climate based on available historical weather data-sets is presented for selected locations in the Philippines. In this study, plausible climate scenarios and downscaled climate projections for representative crop production areas are discussed. Results of downscaling of climate projections for 2020, 2050 and 2080 using a dynamic downscaling procedure and a statistical downscaling method are presented and compared. Impacts of climate change and variability on crop productivity and production systems in selected crop-growing areas in the country are presented. Crop yields using a calibrated crop simulation model for a standard rice variety (IR-64) and a local maize variety (IPB-911) for projected climate were determined. Results indicate a reduction from 8% to 14% in crop yields per 1°C temperature increase depending on season and location. Some adaptation strategies related to agricultural water management to minimize the adverse effects and impacts of climate change are described. These location-specific measures based on best practices include adjusting the planting calendar, improving water use efficiency and irrigation water management, water impoundment, planting stress-tolerant varieties, and weather index-based insurance for crop production.
Groundwater for food production and livelihoods - the nexus with climate change and transboundary water management.
Authors: Villholth K.
Published: December 2015

Groundwater resources in transboundary aquifers may cushion climate change and other impacts of anthropogenic change through irrigation development, which in turn can enhance food security, livelihood benefits and poverty reduction in developing countries. Such resources present significant water reserves that, however, need to undergo critical joint assessment, development and management if they are to provide substantial as well as sustainable scenarios to agricultural and socio-economic development. This chapter explores the nexus between groundwater in shared aquifers, climate change and agricultural growth in the context of Africa, Asia, the Middle East and Latin America and examines the added challenges as well as opportunities that the transboundary setting of these resources may provide in terms of devising lasting solutions. The chapter highlights that both local smaller-scale no-regret as well as larger-scale, strategic adaptation measures that often hinge on integrated surface-groundwater solutions are important. In addition, the socio-economic and institutional aspects, the latter in terms of general international law and specific adapted international agreements as well as bottom-up participatory processes, are critical for attaining success on the ground.
Mitigating greenhouse gas emissions from rice production through water-saving techniques: potential, adoption and empirical evidence.
Authors: Sander B. O. , Wassmann R. , Siopongco J. D. L. C.
Published: December 2015

Flooded rice fields are a large anthropogenic source of the greenhouse gas (GHG) methane (CH4). Aeration of the paddy field can reduce methane emissions and at the same time save water. Different forms of water saving techniques (WST), e.g. alternate wetting and drying (AWD) and midseason drainage (MSD), have been developed and disseminated. This article gives an overview on adoption of AWD in the Philippines and assesses prospects and constraints. It also explains the Clean Development Mechanism (CDM) methodology for rice production and analyses the mitigation potential of WST in the form of a literature review. The adoption rate of AWD strongly depends on the incentive for the farmer. While direct monetary incentives are limited to areas where saving water is directly linked to reduced costs (e.g. pump irrigation systems), indirect incentives (e.g. improved crop development) have not yet been scientifically assessed. The literature meta-analysis proves the great mitigation potential of WST. Methane emissions can be reduced by an average of 36.5% with a single drainage and by 43% with multiple aerations. Nitrous oxide emissions increase under all WST but this increase does not offset the reduction in CH4 emissions. This study also shows that the amount of GHG emissions can vary drastically between different regions. This poses a challenge for the transfer of mitigation strategies from one region to another.
A modified hot tearing criterion for direct chill casting of aluminium alloys
Authors: Bai Q. L. , Liu J. C. , Li H. X. , Du Q. , Katgerman L. , Zhang J. S. , Zhuang L. Z.
Published: December 2015

Using the good criteria to predict hot tearing is very important during DC casting of aluminium alloys. Among all the hot tearing criteria, a fracture-mechanics based SKK criterion proposed by Suyitno et al. has made considerable improvements in the hot tearing prediction. However, its obtained hot tearing susceptibility (HTS) evolution during solidification is also not completely consistent with real industrial production circumstances, especially when approaching the solidus temperature. In this paper, some further modifications are made based on the SKK criterion to emphasise the important effect of solid bridging/grain coalescence on hot tear propagation. It is proved that the HTS evolution in freezing range predicted by the modified hot tearing criterion is in good agreement with casting practice.
Calico Scallop Argopecten gibbus Abundance on the Cape Canaveral Bed and on Florida's Gulf of Mexico Shelf
Authors: Geiger Stephen P. , Arnold William S. , Stephenson Sarah , Fischer Keith
Published: December 2015

Annual landings of the calico scallop Argopecten gibbus fishery in the southeastern United States increased from less than 3,000 kg in 1959 to 19.5 million kg of adductor muscle meat in 1984. The fishery began to collapse in early 1986 in Florida and fell below 1 million kg/year in the mid-1990s. From 2002 through 2011, the only reported landings were 550 kg in 2009, but annual landings of less than 200,000 kg beginning in 2012 indicate the resource rebounded enough in that year to create renewed interest in the fishery. When the fishery was developing, the National Marine Fisheries Service (NMFS) sponsored 59 cruises (1956 through the mid-1970s) to map the distribution of the stock and found the calico scallop stocks on Florida's east coast principally occurred around the 40-m depth contour near the shelf break. By the early 1980s, surveys were no longer routinely conducted. Two surveys in the mid-1990s were dedicated to investigating the collapse of the stock. The present study consisted of eight cruises from 2004 to 2006: four each to the beds off Cape Canaveral on the eastern coast and the poorly documented beds off southwestern Florida. Cruises studying baitfish and cruises in the Gulf of Mexico by the Southeast Area Monitoring and Assessment Program (SEAMAP) yielded data that provided additional calico scallop abundance estimates. Abundant, albeit small, scallops were found on both coasts during three of the four cruises to each coast though none were detected in fall 2004 on either coast. Our results concur with those historic NMFS surveys conducted prior to the period of heaviest exploitation of the resource (1974–1999); the center of distribution for calico scallops on the Cape Canaveral beds still occurs near the 40-m depth contour. The essential habitat for calico scallops, shell base, which was suspected to have declined during the most active fishery periods, was found to have persisted consistently at that depth. There were few scallops with a shell height greater than 40 mm, the minimal size considered acceptable for commercial exploitation.

Received July 9, 2015; accepted September 15, 2015
Receptor editing and genetic variability in human autoreactive B cells
Authors: Lang Julie , Ota Takayuki , Kelly Margot , Strauch Pamela , Freed Brian M. , Torres Raul M. , Nemazee David , Pelanda Roberta
Published: December 2015

The mechanisms by which B cells undergo tolerance, such as receptor editing, clonal deletion, and anergy, have been established in mice. However, corroborating these mechanisms in humans remains challenging. To study how autoreactive human B cells undergo tolerance, we developed a novel humanized mouse model. Mice expressing an anti–human Igκ membrane protein to serve as a ubiquitous neo self-antigen (Ag) were transplanted with a human immune system. By following the fate of self-reactive human κ+ B cells relative to nonautoreactive λ+ cells, we show that tolerance of human B cells occurs at the first site of self-Ag encounter, the bone marrow, via a combination of receptor editing and clonal deletion. Moreover, the amount of available self-Ag and the genetics of the cord blood donor dictate the levels of central tolerance and autoreactive B cells in the periphery. Thus, this model can be useful for studying specific mechanisms of human B cell tolerance and to reveal differences in the extent of this process among human populations.
Activity profiles and hook-tool use of New Caledonian crows recorded by bird-borne video cameras
Authors: Troscianko Jolyon , Rutz Christian
Published: December 2015

New Caledonian crows are renowned for their unusually sophisticated tool behaviour. Despite decades of fieldwork, however, very little is known about how they make and use their foraging tools in the wild, which is largely owing to the difficulties in observing these shy forest birds. To obtain first estimates of activity budgets, as well as close-up observations of tool-assisted foraging, we equipped 19 wild crows with self-developed miniature video cameras, yielding more than 10 h of analysable video footage for 10 subjects. While only four crows used tools during recording sessions, they did so extensively: across all 10 birds, we conservatively estimate that tool-related behaviour occurred in 3% of total observation time, and accounted for 19% of all foraging behaviour. Our video-loggers provided first footage of crows manufacturing, and using, one of their most complex tool types—hooked stick tools—under completely natural foraging conditions. We recorded manufacture from live branches of paperbark (Melaleucasp.) and another tree species (thought to beAcacia spirorbis), and deployment of tools in a range of contexts, including on the forest floor. Taken together, our video recordings reveal an ‘expanded’ foraging niche for hooked stick tools, and highlight more generally how crows routinely switch between tool- and bill-assisted foraging.
Lift enhancement by bats' dynamically changing wingspan
Authors: Wang Shizhao , Zhang Xing , He Guowei , Liu Tianshu
Published: December 2015

This paper elucidates the aerodynamic role of the dynamically changing wingspan in bat flight. Based on direct numerical simulations of the flow over a slow-flying bat, it is found that the dynamically changing wingspan can significantly enhance the lift. Further, an analysis of flow structures and lift decomposition reveal that the elevated vortex lift associated with the leading-edge vortices intensified by the dynamically changing wingspan considerably contributed to enhancement of the time-averaged lift. The nonlinear interaction between the dynamically changing wing and the vortical structures plays an important role in the lift enhancement of a flying bat in addition to the geometrical effect of changing the lifting-surface area in a flapping cycle. In addition, the dynamically changing wingspan leads to the higher efficiency in terms of generating lift for a given amount of the mechanical energy consumed in flight.
Disinhibition of the HECT E3 ubiquitin ligase WWP2 by polymerized Dishevelled
Authors: Mund Thomas , Graeb Michael , Mieszczanek Juliusz , Gammons Melissa , Pelham Hugh R. B. , Bienz Mariann
Published: December 2015

Dishevelled is a pivot in Wnt signal transduction, controlling both β-catenin-dependent transcription to specify proliferative cell fates, and cell polarity and other non-nuclear events in post-mitotic cells. In response to Wnt signals, or when present at high levels, Dishevelled forms signalosomes by dynamic polymerization. Its levels are controlled by ubiquitylation, mediated by various ubiquitin ligases, including NEDD4 family members that bind to a conserved PPxY motif in Dishevelled (mammalian Dvl1–3). Here, we show that Dvl2 binds to the ubiquitin ligase WWP2 and unlocks its ligase activity from autoinhibition. This disinhibition of WWP2 depends on several features of Dvl2 including its PPxY motif and to a lesser extent its DEP domain, but crucially on the ability of Dvl2 to polymerize, indicating that WWP2 is activated in Wnt signalosomes. We show that Notch intracellular domains are substrates for Dvl-activated WWP2 and their transcriptional activity is consequently reduced, providing a molecular mechanism for cross-talk between Wnt and Notch signalling. These regulatory interactions are conserved inDrosophilawhose WWP2 orthologue, Suppressor-of-deltex, downregulates Notch signalling upon activation by Dishevelled in developing wing tissue. Attentuation of Notch signalling by Dishevelled signalosomes could be important during the transition of cells from the proliferative to the post-mitotic state.
Marine reserve recovery rates towards a baseline are slower for reef fish community life histories than biomass
Authors: McClanahan T. R. , Graham N. A. J.
Published: December 2015

Ecological baselines are disappearing and it is uncertain how marine reserves, here called fisheries closures, simulate pristine communities. We tested the influence of fisheries closure age, size and compliance on recovery of community biomass and life-history metrics towards a baseline. We used census data from 324 coral reefs, including 41 protected areas ranging between 1 and 45 years of age and 0.28 and 1430 km
2
, and 36 sites in a remote baseline, the Chagos Archipelago. Fish community-level life histories changed towards larger and later maturing fauna with increasing closure age, size and compliance. In high compliance closures, community biomass levelled at approximately 20 years and 10 km
2
but was still only at approximately 30% of the baseline and community growth rates were projected to slowly decline for more than 100 years. In low compliance and young closures, biomass levelled at half the value and time as high compliance closures and life-history metrics were not predicted to reach the baseline. Biomass does not adequately reflect the long-time scales for full recovery of life-history characteristics, with implications for coral reef management.
Evolutionary stability of sex chromosomes in snakes
Authors: Rovatsos Michail , Vukić Jasna , Lymberakis Petros , Kratochvíl Lukáš
Published: December 2015

Amniote vertebrates possess various mechanisms of sex determination, but their variability is not equally distributed. The large evolutionary stability of sex chromosomes in viviparous mammals and birds was believed to be connected with their endothermy. However, some ectotherm lineages seem to be comparably conserved in sex determination, but previously there was a lack of molecular evidence to confirm this. Here, we document a stability of sex chromosomes in advanced snakes based on the testing of Z-specificity of genes using quantitative PCR (qPCR) across 37 snake species (our qPCR technique is suitable for molecular sexing in potentially all advanced snakes). We discovered that at least part of sex chromosomes is homologous across all families of caenophidian snakes (Acrochordidae, Xenodermatidae, Pareatidae, Viperidae, Homalopsidae, Colubridae, Elapidae and Lamprophiidae). The emergence of differentiated sex chromosomes can be dated back to about 60 Ma and preceded the extensive diversification of advanced snakes, the group with more than 3000 species. The Z-specific genes of caenophidian snakes are (pseudo)autosomal in the members of the snake families Pythonidae, Xenopeltidae, Boidae, Erycidae and Sanziniidae, as well as in outgroups with differentiated sex chromosomes such as monitor lizards, iguanas and chameleons. Along with iguanas, advanced snakes are therefore another example of ectothermic amniotes with a long-term stability of sex chromosomes comparable with endotherms.
Phase diagram of the Nd2Fe14B–Sm2Fe14B pseudo-binary system
Authors: Xu Ch. F. , Chen K. H. , Gu Z. F. , Cheng L. Y. , Ma D. D. , Cheng G. , Rao G. H. , Yao Q. R.
Published: December 2015

The phase relations in the (1−x)Nd2Fe14B–xSm2Fe14B system over the whole concentration range have been studied by means of X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Crystal structure parameters for all studied compositions of (Nd1−xSmx)2Fe14B have been determined by full-profile Rietveld refinements. These results revealed that all intermediate alloys of (Nd1−xSmx)2Fe14B are similar to the end member of the investigated system, Nd2Fe14B, with a tetragonal structure (space groupP42/mnm). The formation of continuous solid solutions has been found in this system. The normalized lattice parameters and unit-cell volumes of (Nd1−xSmx)2Fe14B solid solutions decrease linearly with increasing Sm content. The DTA measurements show that the melting temperature of (Nd1−xSmx)2Fe14B increases linearly with increasing Sm content and no metastable phases were detected. Based on the DTA data and XRD results, a tentative phase diagram for the pseudo-binary system Nd2Fe14B–Sm2Fe14B has been constructed.
COD::CIF::Parser: an error-correcting CIF parser for the Perl language
Authors: Merkys Andrius , Vaitkus Antanas , Butkus Justas , Okulič-Kazarinas Mykolas , Kairys Visvaldas , Gražulis Saulius
Published: December 2015

A syntax-correcting CIF parser,COD::CIF::Parser, is presented that can parse CIF 1.1 files and accurately report the position and the nature of the discovered syntactic problems. In addition, the parser is able to automatically fix the most common and the most obvious syntactic deficiencies of the input files. Bindings for Perl, C and Python programming environments are available. Based onCOD::CIF::Parser, thecod-toolspackage for manipulating the CIFs in the Crystallography Open Database (COD) has been developed. Thecod-toolspackage has been successfully used for continuous updates of the data in the automated COD data deposition pipeline, and to check the validity of COD data against the IUCr data validation guidelines. The performance, capabilities and applications of different parsers are compared.
PhotonDiag2015 workshop: introductory overview
Authors: Cocco Daniele , Plönjes Elke , Zangrando Marco
Published: December 2015

This issue of the Journal of Synchrotron Radiation is a special issue including papers from the PhotonDiag2015 workshop. Here, a brief introduction is given.
6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two tautomers present in the same crystal?
Authors: Gerhardt Valeska , Bolte Michael
Published: December 2015

It is well known that pyrimidin-4-one derivatives are able to adopt either the 1H- or the 3H-tautomeric form in (co)crystals, depending on the coformer. As part of ongoing research to investigate the preferred hydrogen-bonding patterns of active pharmaceutical ingredients and their model systems, 2-amino-6-chloropyrimidin-4-one and 2-amino-5-bromo-6-methylpyrimidin-4-one have been cocrystallized with several coformers and with each other. Since Cl and Br atoms both have versatile possibilities to interact with the coformers, such asviahydrogen or halogen bonds, their behaviour within the crystal packing was also of interest. The experiments yielded five crystal structures, namely 2-aminopyridin-1-ium 2-amino-6-chloro-4-oxo-4H-pyrimidin-3-ide–2-amino-6-chloropyrimidin-4(3H)-one (1/3), C5H7N2+·C4H3ClN3O−·3C4H4ClN3O, (Ia), 2-aminopyridin-1-ium 2-amino-6-chloro-4-oxo-4H-pyrimidin-3-ide–2-amino-6-chloropyrimidin-4(3H)-one–2-aminopyridine (2/10/1), 2C5H7N2+·2C4H3ClN3O−·10C4H4ClN3O·C5H6N2, (Ib), the solvent-free cocrystal 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one–2-amino-5-bromo-6-methylpyrimidin-4(1H)-one (1/1), C5H6BrN3O·C5H6BrN3O, (II), the solvate 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one–2-amino-5-bromo-6-methylpyrimidin-4(1H)-one–N-methylpyrrolidin-2-one (1/1/1), C5H6BrN3O·C5H6BrN3O·C5H9NO, (III), and the partial cocrystal 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one–2-amino-5-bromo-6-methylpyrimidin-4(1H)-one–2-amino-6-chloropyrimidin-4(3H)-one (0.635/1/0.365), C5H6BrN3O·C5H6BrN3O·C4H4ClN3O, (IV). All five structures showR22(8) hydrogen-bond-based patterns, either by synthon 2 or by synthon 3, which are related to the Watson–Crick base pairs.
Sqt1p is an eight-bladed WD40 protein
Authors: Frénois Frédéric , Legrand Pierre , Fribourg Sébastien
Published: December 2015

Ribosome biogenesis in eukaryotes is a complex and highly orchestrated process involving more than 200 accessory factors in addition to ribosomal RNAs and ribosomal proteins. Among the many factors involved, Sqt1p has been reported to specifically bind to uL16 and to act as a chaperone. The crystal structure of full-length Sqt1p from the yeastSaccharomyces cerevisiaehas been solved at 3.35 Å resolution. A SAD experiment at the Se Kedge and an S-SAD experiment on the same selenomethionine-substituted protein crystal allowed unambiguous positioning of the selenomethionine and Cys residues. On the basis of the atomic structure of Sqt1p, the potential residues involved in uL16 interaction were identified and tested.
Crystal structure of 3-(diethylamino)phenol
Authors: Golen James A. , McDonald Kyle J. , Manke David R.
Published: December 2015

The title compound, C10H15NO, has two molecules in the asymmetric unit. Each molecule has a near-planar C8NO unit excluding H atoms and the terminal methyl groups on the diethylamino groups, with mean deviations from planarity of 0.036 and 0.063 Å. In the crystal, hydrogen bonding leads to four-membered O—H...O—H...O—H·· rings. No π–π interactions were observed in the structure.
Tetraethyl pyrazine-2,3,5,6-tetracarboxylate
Authors: Wang Yi , Stoeckli-Evans Helen
Published: December 2015

The whole molecule of the title compound, C16H20N2O8, is generated by inversion symmetry. The adjacent carboxylate groups [C(=O)—O—C] are inclined to the pyrazine ring by 72.40 (10) and 19.64 (10)°, and to one another by 68.21 (12)°. In the crystal, molecules stack along thea-axis direction but there are no significant intermolecular interactions present.
trans-Dichlorido{3,4-dimethoxy-2-[(2,3-η)-prop-2-en-1-yl]benzene}(pyridine-κN)platinum(II)
Authors: Bui Thi Yen Hang , Nguyen Thi Thanh Chi , Van Meervelt Luc
Published: December 2015

In the title organoplatinum(II) complex, [PtCl2(C5H5N)(C11H14O2)], the methyleugenol ligand only coordinates to the PtIIatom through the ethylenic double bond. The coordination is completed by the N atom of the pyridine ligand and two Cl atoms positionedtranswith respect to each other. The pyridine and benzene rings are inclined to one another by 68.6 (2)°. In the crystal, molecules are linkedviaa number of C—H...Cl and C—H...O hydrogen bonds, forming sheets parallel to thebcplane.
2-Chloro-1-ferrocenylethanone
Authors: McAdam C. John , Simpson Jim
Published: December 2015

The title molecule, [Fe(C5H5)(C7H6ClO)], comprises a ferrocene unit with a 2-chloroethanone substituent on one of the cyclopentadienyl (Cp) rings. The two Cp rings are almost coplanar with an angle of 1.28 (1)° between them. In the crystal, C—H...Cl and C—H...O hydrogen bonds together with an edge-to-face C—H...π contact involving the unsubstituted Cp ring stack molecules along thec-axis direction.
Expression of PD‐1/LAG‐3 and cytokine production by CD4+ T cells during infection with Plasmodium parasites
Authors: Doe Henrietta T. , Kimura Daisuke , Miyakoda Mana , Kimura Kazumi , Akbari Masoud , Yui Katsuyuki
Published: December 2015

CD4+ T cells play critical roles in protection against the blood stage of malarial infection; however, their uncontrolled activation can be harmful to the host. In this study, in which rodent models of Plasmodium parasites were used, the expression of inhibitory receptors on activated CD4+ T cells and their cytokine production was compared with their expression in a bacterial and another protozoan infection. CD4+ T cells from mice infected with P. yoelii 17XL, P yoelii 17XNL, P. chabaudi, P. vinckei and P. berghei expressed the inhibitory receptors, PD‐1 and LAG‐3, as early as 6 days after infection, whereas those from either Listeria monocytogenes‐ or Leishmania major‐infected mice did not. In response to T‐cell receptor stimulation, CD4+ T cells from mice infected with all the pathogens under study produced high concentrations of IFN‐γ. IL‐2 production was reduced in mice infected with Plasmodium species, but not in those infected with Listeria or Leishmania. In vitro blockade of the interaction between PD‐1 and its ligands resulted in increased IFN‐γ production in response to Plasmodium antigens, implying that PD‐1 expressed on activated CD4+ T cells actively inhibits T cell immune responses. Studies using Myd88−/−, Trif−/− and Irf3−/− mice showed that induction of these CD4+ T cells and their ability to produce cytokines is largely independent of TLR signaling. These studies suggest that expression of the inhibitory receptors PD‐1 and LAG‐3 on CD4+ T cells and their reduced IL‐2 production are common characteristic features of Plasmodium infection.