bluuebunny/crossref_metadata_2025 huggingface dataset:
An experimental evaluation of autonomous underwater vehicle localization on geomagnetic map
Authors: Wu Zhitian , Hu Xiaoping , Wu Meiping , Mu Hua , Cao Juliang , Zhang Kaidong , Tuo Zhouhui
Published: September 2013

This letter reports an experimental evaluation of a three-axis magnetometer into an inertial navigation system (INS) for underwater localization. The magnetometer measurements of geomagnetic field are compared with map values to provide position updates to the INS. The concept of such navigation system is not new but lacks test verification and actual application. We examine the capabilities of the integrated navigation by using a localization algorithm based on the interval knowledge of geomagnetic field values. The underwater experimental result indicates that the use of geomagnetic values significantly reduces the growth of position errors of an INS.
Ga nanoparticle-enhanced photoluminescence of GaAs
Authors: Kang M. , Al-Heji A. A. , Lee J.-E. , Saucer T. W. , Jeon S. , Wu J. H. , Zhao L. , Katzenstein A. L. , Sofferman D. L. , Sih V. , Goldman R. S.
Published: September 2013

We have examined the influence of surface Ga nanoparticles (NPs) on the enhancement of GaAs photoluminescence (PL) efficiency. We have utilized off-normal focused-ion-beam irradiation of GaAs surfaces to fabricate close-packed Ga NP arrays. The enhancement in PL efficiency is inversely proportional to the Ga NP diameter. The maximum PL enhancement occurs for the Ga NP diameter predicted to maximize the incident electromagnetic (EM) field enhancement. The PL enhancement is driven by the surface plasmon resonance (SPR)-induced enhancement of the incident EM field which overwhelms the SPR-induced suppression of the light emission.
The pumpistor: A linearized model of a flux-pumped superconducting quantum interference device for use as a negative-resistance parametric amplifier
Authors: Sundqvist K. M. , Kintaş S. , Simoen M. , Krantz P. , Sandberg M. , Wilson C. M. , Delsing P.
Published: September 2013

We describe a circuit model for a flux-driven Superconducting QUantum Interference Device (SQUID). This is useful for developing insight into how these devices perform as active elements in parametric amplifiers. The key concept is that frequency mixing in a flux-pumped SQUID allows for the appearance of an effective negative resistance. In the three-wave, degenerate case treated here, a negative resistance appears only over a certain range of allowed input signal phase. This model readily lends itself to testable predictions of more complicated circuits.
Effect of GaAs interfacial layer on the performance of high bandgap tunnel junctions for multijunction solar cells
Authors: Samberg Joshua P. , Zachary Carlin C. , Bradshaw Geoff K. , Colter Peter C. , Harmon Jeffrey L. , Allen J. B. , Hauser John R. , Bedair S. M.
Published: September 2013

The effect of the heterojunction interface on the performance of high bandgap InxGa1−xP:Te/Al0.6Ga0.4As:C tunnel junctions (TJs) was investigated. The insertion of 30 Å of GaAs:Te at the junction interface resulted in a peak current of 1000 A/cm2 and a voltage drop of ∼3 mV for 30 A/cm2 (2000× concentration). The presence of this GaAs interfacial layer also improved the uniformity across the wafer. Modeling results are consistent with experimental data and were used to explain the observed enhancement in TJ performance. This architecture could be used within multijunction solar cells to extend the range of usable solar concentration with minimal voltage drop.
Anomalously strong nonlinearity of unswept quartz acoustic cavities at liquid helium temperatures
Authors: Goryachev Maxim , Farr Warrick G. , Ivanov Eugene N. , Tobar Michael E.
Published: September 2013

We demonstrate a variety of nonlinear phenomena at extremely low powers in cryogenic acoustic cavities fabricated from quartz material, which have not undergone any electrodiffusion processes. Nonlinear phenomena observed include lineshape discontinuities, power response discontinuities, quadrature oscillations, and self-induced transparency. These phenomena are attributed to nonlinear dissipation through a large number of randomly distributed heavy trapped ions, which would normally be removed by electrodiffusion. A simple mean-field model predicts most of the observed phenomena. In contrast to Duffing-like systems, this system shows an unusual mechanism of nonlinearity, which is not related to crystal anharmonicity.
Growth and characterization of rugged sodium potassium antimonide photocathodes for high brilliance photoinjector
Authors: Cultrera L. , Karkare S. , Lillard B. , Bartnik A. , Bazarov I. , Dunham B. , Schaff W. , Smolenski K.
Published: September 2013

Sodium potassium antimonide photocathodes with Quantum Efficiency (QE) in the range of few percent have been grown, and their photoemission properties are measured. We report the intrinsic emittance and response time of electron bunches extracted from this material. It is possible to recover the QE of an overheated cathode by simple potassium addition, and the cathode is rugged enough to deliver tens of mA of average current with no or minimal degradation.
Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings
Authors: Kats Mikhail A. , Byrnes Steven J. , Blanchard Romain , Kolle Mathias , Genevet Patrice , Aizenberg Joanna , Capasso Federico
Published: September 2013

Recently a new class of optical interference coatings was introduced which comprises ultra-thin, highly absorbing dielectric layers on metal substrates. We show that these lossy coatings can be augmented by an additional transparent subwavelength layer. We fabricated a sample comprising a gold substrate, an ultra-thin film of germanium with a thickness gradient, and several alumina films. The experimental reflectivity spectra showed that the additional alumina layer increases the color range that can be obtained, in agreement with calculations. More generally, this transparent layer can be used to enhance optical absorption, protect against erosion, or as a transparent electrode for optoelectronic devices.
Atomistic origin of glass-like Zn4Sb3 thermal conductivity
Authors: Li Xudong , Carrete Jesús , Lin Jianping , Qiao Guanjun , Wang Zhao
Published: September 2013

Zinc antimony stands out among thermoelectrics because of its very low lattice thermal conductivity, close to the amorphous limit. Understanding the physical reason behind such an unusual crystal property is of fundamental interest for the design of new thermoelectric materials. In this work, we report the results of atomistic computer simulations on experimentally determined β-Zn4Sb3 structures. We find a remarkably anharmonic behavior of interstitial Zn atoms that could be responsible for the low thermal conductivity of Zn4Sb3: their movement, better explained as diffusive, does not contribute to thermal conduction. Moreover, phonon transport is impeded by a lack of coupling between Zn and Sb atoms in crystalline positions.
Understanding of ferromagnetism in thiol capped Mn doped CdS nanocrystals
Authors: Ghosh Anirudha , Paul Sanhita , Raj Satyabrata
Published: September 2013

The evolution of ferromagnetism has been investigated in thiol (2-mercaptoethanol) capped Mn doped CdS nanoparticles synthesized at various temperatures by sol-gel reverse micelle mechanism. X-ray diffraction measurements reveal a structural phase transformation from wurtzite to zinc blende structure with the increase in synthesis temperature of Mn doped nanocryatals. Magnetic measurements suggest that the antiferromagnetic interactions of Mn2+ ions within Mn—cluster in Mn doped CdS nanocrystals synthesized at lower temperature (∼17 °C) reduce the total magnetic moment at ambient temperature. Whereas the isolated Mn2+ ions in nanocrystals synthesized above 70 °C enhance the magnetic moment due to the sp-d exchange interaction at ambient temperature. It has been observed that the magnetic moments in all samples synthesized at various temperatures do not saturate even at lowest temperature, 5 K. The core diamagnetism in doped nanocrystals synthesized at low temperature (∼17 °C) is mostly due to the presence of magnetic ions around the surface, whereas these ions exist randomly throughout the crystal for samples synthesized at high temperature (∼70 °C), as a result core diamagnetism vanishes.
Note: Determination of torsional spring constant of atomic force microscopy cantilevers: Combining normal spring constant and classical beam theory
Authors: Álvarez-Asencio R. , Thormann E. , Rutland M. W.
Published: September 2013

A technique has been developed for the calculation of torsional spring constants for AFM cantilevers based on the combination of the normal spring constant and plate/beam theory. It is easy to apply and allow the determination of torsional constants for stiff cantilevers where the thermal power spectrum is difficult to obtain due to the high resonance frequency and low signal/noise ratio. The applicability is shown to be general and this simple approach can thus be used to obtain torsional constants for any beam shaped cantilever.
A new scaling relation for n-AlN doped superconducting MgB2
Authors: Tripathi D. , Dey T. K.
Published: September 2013

The scaling behavior of nano-aluminum nitride added polycrystalline MgB2 superconductor is discussed. A series of polycrystalline MgB2 samples with different amounts of nanosized AlN addition are synthesized by solid reaction. All the synthesized pellets are subjected to x-ray diffraction, field emission gun scanning electron microscopy (FEG-SEM), and transmission electron microscopy (TEM) to examine their micro-structural features. A marginal decrease in lattice parameters of pure MgB2 with AlN nanoparticles addition is observed. Surface morphology reveals randomly oriented hexagonal MgB2 grains decorated with AlN nanoparticles between the grain boundaries and also scattered on the grain surface. For higher concentration, n-AlN agglomerates are visible. Resistivity data confirm a decrease in superconducting transition temperature (Tc) from 38.5 to 37 K and increase in transition width (ΔTc) with increased loading of n-AlN in MgB2. The critical current density (Jc) of the pellets at 4, 10, 20, and 30 K is evaluated from the magnetization data between ±6 T and is explained well in the framework of collective pinning model. The normalized pinning force density of n-AlN doped MgB2 at various temperatures indicates an excellent scaling with respect to Hn (the field corresponding to which Fp drops to half of its maximum value) as the scaling field. A new scaling expression derived, using the expression of field dependence of Jc proposed by “collective pinning model” in small bundle regime, demonstrates an excellent agreement with the measured normalized pinning force density (viz., Fp/Fpmax vs. hn) of the AlN nanoparticles doped MgB2 superconductors.
The strain models of misfit dislocations at cubic semiconductors hetero-interfaces
Authors: Wang Yi , Ruterana P.
Published: September 2013

The misfit dislocations at cubic semiconductors hetero-interfaces were quantitatively investigated by high angle dark field scanning transmission electron microscopy in combination with geometric phase analysis and dislocation density tensor analysis. A detailed comparison of the extracted information with the available dislocation models (Peierls-Nabarro and Foreman model) in bulk materials shows that these models can be adapted to the misfit dislocations at lattice mismatched interface. A typical illustration is made for GaSb/GaAs, where it is shown that the strain fields of the 60° dislocation follows the Foreman model (a = 1.8), in case of the Lomer and 60° dislocation pair, the Foreman (a = 2.5) and Peierls-Nabarro model apply for εxx and εyy, respectively.
Electrical properties of scandium nitride epitaxial films grown on (100) magnesium oxide substrates by molecular beam epitaxy
Authors: Ohgaki Takeshi , Watanabe Ken , Adachi Yutaka , Sakaguchi Isao , Hishita Shunichi , Ohashi Naoki , Haneda Hajime
Published: September 2013

Scandium nitride (ScN) films were grown on (100) MgO single crystals by a molecular beam epitaxy method. The effects of growth conditions, including [Sc]/[N] ratio, growth temperature, and nitrogen radical state, on the electrical properties of the ScN films were studied. The ScN films comprised many small columnar grains. Hall coefficient measurements confirmed that the ScN films were highly degenerate n-type semiconductors and that the carrier concentration of the ScN films was sensitive to the growth temperature and the nitrogen radical states during the film growth. The carrier concentrations of the ScN films ranged from 1019–1021 cm−3 while the Hall mobilities ranged from 50–130 cm2·V−1·s−1 for undoped films. The temperature-dependent Hall coefficient measurements showed that the carrier concentration is nearly independent of temperature, indicating that the change in resistivity with temperature is explained by a change in the Hall mobility. The temperature-dependence of the Hall mobility was strongly affected by the growth conditions.
Field emission from laterally aligned carbon nanotube flower arrays for low turn-on field emission
Authors: Kimura Hiroe , Zhao Bin , Futaba Don N. , Yamada Takeo , Kurachi Hiroyuki , Uemura Sashiro , Hata Kenji
Published: September 2013

Laterally aligned carbon nanotube (CNT) arrays “blossomed” homogeneously in honeycomb holes of a metal grid substrate were explored as rational architecture for field emission. A low turn-on field (TOF) of 1.09 V/μm for 10 μA/cm2 emission was achieved, which approaches or exceeds the lowest reported TOF values for field emitter arrays. We interpret that these lateral CNT arrays act as source of CNT “loop” arrays enabling a structure suited toward low TOF field emission.
Chemically exfoliated large-area two-dimensional flakes of molybdenum disulfide for device applications
Authors: Pachauri Vivek , Kern Klaus , Balasubramanian Kannan
Published: September 2013

A solution-based exfoliation method for obtaining large-area two-dimensional flakes of molybdenum disulfide, followed by the fabrication of electrical devices is presented in this manuscript. The exfoliation method is based on the use of an aprotic solvent, namely, acetonitrile under mild sonication steps. In order to fabricate devices, a dielectrophoresis technique is used for transferring MoS2 flakes site-specifically on to the electrode pairs pre-written on the glass chips. The devices fabricated thus can be operated as chemical sensor in liquids while investigations under photo illumination indicate that such devices can also efficiently function as photodetectors.
Film of lignocellulosic carbon material for self-supporting electrodes in electric double-layer capacitors
Authors: Funabashi Tsubasa , Mizuno Jun , Sato Masamichi , Kitajima Masao , Matsuura Makoto , Shoji Shuichi
Published: September 2013

A novel thin, wood-based carbon material with heterogeneous pores, film of lignocellulosic carbon material (FLCM), was successfully fabricated by carbonizing softwood samples of Picea jezoensis (Jezo spruce). Simultaneous increase in the specific surface area of FLCM and its affinity for electrolyte solvents in an electric double-layer capacitor (EDLC) were achieved by the vacuum ultraviolet/ozone (VUV/O3) treatment. This treatment increased the specific surface area of FLCM by 50% over that of original FLCM. The results obtained in this study confirmed that FLCM is an appropriate self-supporting EDLC electrode material without any warps and cracks.
Controllable fabrication and optical properties of Sn-doped ZnO hexagonal microdisk for whispering gallery mode microlaser
Authors: Dai J. , Xu C. X. , Xu X. Y. , Li J. T. , Guo J. Y. , Lin Y.
Published: September 2013

We report a controllable method for fabricating hexagonal Sn doped ZnO microdisks. The photoluminescence mechanism of the Sn doped ZnO microdisks is investigated, the defect emission is attributed to the singly charged oxygen vacancy. Under the excitation of a femtosecond pulsed laser with a wavelength of 325 nm, exciton-exciton collision process is clearly demonstrated, and amplified spontaneous emission is further realized under strong excitation. Using the perfect hexagonal symmetric structure of the Sn doped ZnO microdisks, the whispering-gallery mode lasing with high quality factor and fine mode structure is obtained from a single microdisk.
Shape modification of Si nanowires by using faceted silicide catalysts nucleated in Au-Si catalyst solution during the growth
Authors: Meng Erchao , Li Wen , Nakane Kaito , Shirahashi Yuya , Hayakawa Yasuhiro , Tatsuoka Hirokazu
Published: September 2013

The shape modification of Si nanowires is demonstrated using faceted solid silicide catalysts. The Si nanowires were grown on Si(111) substrates covered with Au as a catalyst using MnCl2 and Si powders as source materials. The solid silicide catalysts were nucleated and formed in the Au-Si catalyst solution at the top of the nanowires during the growth. The faceted solid silicides grew larger with increased growth time and played a role as a solid catalyst. The faceted shape of the catalyst defines the shape of the faceted Si nanowire. The squared Si nanowires were grown with the growth direction of Si[111] and the sidewalls of {110} and {211} planes. The growth evolution of the faceted Si nanowires occurs by a vapor-liquid-solid mechanism followed by the silicide vapor-solid-solid mechanism.
Taking near infrared spectroscopy beyond feedstuff analysis to enhance animal production profitability
Authors: Graham Hadden , Piotrowski Chris , Van Barneveld Robert
Published: September 2013

Near infrared reflectance (NIR) spectroscopy allows a cheap and rapid estimation of composition, and thus is widely used in the animal feed industry for the quality control and quality assurance of feeds and particularly feed ingredients. However, such analyses are often limited to a few variables not closely related to the nutritive value of the particular feed ingredients, and are often retrospective. This paper discusses recent developments in both hardware and software, which now allow real-time and in-line analysis of feed ingredients and feeds, and how these can be used to save substantial costs in the feed industry worldwide by reducing feed costs and giving more predictable animal performance. We also discuss how laboratory, hand-held and in-line NIR equipment could be widely used in the future for the purchase of feed ingredients and the manufacture of animal feeds.
Interrogating Fragments Using a Protein Thermal Shift Assay
Authors: McMahon Róisín M. , Scanlon Martin J. , Martin Jennifer L.
Published: September 2013

Protein thermal shift is a relatively rapid and inexpensive technique for the identification of low molecular weight compound interactions with protein targets. An increase in the melting temperature of the target protein in the presence of a test ligand is indicative of a promising ligand–protein interaction. Due to its simplicity, protein thermal shift is an attractive method for screening libraries and validating hits in drug discovery programs. The methodology has been used successfully in high throughput screens of small molecule libraries, and its application has been extended to report on protein–drug-like-fragment interactions. Here, we review how protein thermal shift has been employed recently in fragment-based drug discovery (FBDD) efforts, and highlight its application to protein–protein interaction targets. Multiple validation of fragment hits by independent means is paramount to ensure efficient and economical progress in a FBDD campaign. We discuss the applicability of thermal shift assays in this light, and discuss more generally what one does when orthogonal approaches disagree.
Development and evaluation of a field-based high-throughput phenotyping platform
Authors: Andrade-Sanchez Pedro , Gore Michael A. , Heun John T. , Thorp Kelly R. , Carmo-Silva A. Elizabete , French Andrew N. , Salvucci Michael E. , White Jeffrey W.
Published: September 2013

Physiological and developmental traits that vary over time are difficult to phenotype under relevant growing conditions. In this light, we developed a novel system for phenotyping dynamic traits in the field. System performance was evaluated on 25 Pima cotton (Gossypium barbadense L.) cultivars grown in 2011 at Maricopa, Arizona. Field-grown plants were irrigated under well watered and water-limited conditions, with measurements taken at different times on 3 days in July and August. The system carried four sets of sensors to measure canopy height, reflectance and temperature simultaneously on four adjacent rows, enabling the collection of phenotypic data at a rate of 0.84 ha h–1. Measurements of canopy height, normalised difference vegetation index and temperature all showed large differences among cultivars and expected interactions of cultivars with water regime and time of day. Broad-sense heritabilities (H2)were highest for canopy height (H2 = 0.86–0.96), followed by the more environmentally sensitive normalised difference vegetation index (H2 = 0.28–0.90) and temperature (H2 = 0.01–0.90) traits. We also found a strong agreement (r2 = 0.35–0.82) between values obtained by the system, and values from aerial imagery and manual phenotyping approaches. Taken together, these results confirmed the ability of the phenotyping system to measure multiple traits rapidly and accurately.
Recovery of the endangered trout cod, Maccullochella macquariensis: what have we achieved in more than 25 years?
Authors: Koehn John D. , Lintermans Mark , Lyon Jarod P. , Ingram Brett A. , Gilligan Dean M. , Todd Charles R. , Douglas John W.
Published: September 2013

Recovery of threatened species is often necessarily a long-term process. The present paper details the progress towards the recovery of trout cod, Maccullochella macquariensis, an iconic, long-lived fish species first listed as threatened in the 1980s. The objectives, actions and progress over three successive national recovery plans (spanning 18 years) are assessed, documenting changes to population distribution and abundance and updating ecological knowledge. Increased knowledge (especially breeding biology and hatchery techniques, movements, habitats and genetics) has greatly influenced recovery actions and the use of a population model was developed to assist with management options and stocking regimes. Key recovery actions include stocking of hatchery-produced fish to establish new populations, regulations on angling (including closures), education (particularly identification from the closely related Murray cod, M. peelii) and habitat rehabilitation (especially re-instatement of structural woody habitats). In particular, the establishment of new populations using hatchery stocking has been a successful action. The importance of a coordinated long-term approach is emphasised and, although there is uncertainty in ongoing resourcing of the recovery program, much has been achieved and there is cautious optimism for the future of this species.
Systematic review of the types of methods and approaches used to assess the effectiveness of healthcare information websites
Authors: Tieman Jennifer , Bradley Sandra L.
Published: September 2013

The aim of this systematic review was to identify types of approaches and methods used to evaluate the effectiveness of healthcare information websites. Simple usage data may not be sufficient to assess whether desired healthcare outcomes were achieved or to determine the relative effectiveness of different web resources on the same health topic. To establish the state of the knowledge base on assessment methods used to determine the effectiveness of healthcare websites, a structured search of the literature was conducted in Ovid Medline, resulting in the retrieval of 1611 articles, of which 240 met the inclusion criteria for the present review. The present review found that diverse evaluation methods were used to measure the effectiveness of healthcare websites. These evaluation methods were used during development, before release and after release. Economic assessment was rare and most evaluations looked at content issues, such as readability scores. Several studies did try to assess the usefulness of websites, but few studies looked at behaviour change or knowledge transfer following engagement with the designated health website. To assess the effectiveness of the knowledge transfer of healthcare information through the online environment, multiple methods may need to be used to evaluate healthcare websites and may need to be undertaken at all stages of the website development process.
Binding constants of membrane-anchored receptors and ligands depend strongly on the nanoscale roughness of membranes
Authors: Hu Jinglei , Lipowsky Reinhard , Weikl Thomas R.
Published: September 2013

Cell adhesion and the adhesion of vesicles to the membranes of cells or organelles are pivotal for immune responses, tissue formation, and cell signaling. The adhesion processes depend sensitively on the binding constant of the membrane-anchored receptor and ligand proteins that mediate adhesion, but this constant is difficult to measure in experiments. We have investigated the binding of membrane-anchored receptor and ligand proteins with molecular dynamics simulations. We find that the binding constant of the anchored proteins strongly decreases with the membrane roughness caused by thermally excited membrane shape fluctuations on nanoscales. We present a theory that explains the roughness dependence of the binding constant for the anchored proteins from membrane confinement and that relates this constant to the binding constant of soluble proteins without membrane anchors. Because the binding constant of soluble proteins is readily accessible in experiments, our results provide a useful route to compute the binding constant of membrane-anchored receptor and ligand proteins.
Cultural interfaces of self-determination and the rise of the neo-Biafran movement in Nigeria
Authors: Onuoha Godwin
Published: September 2013

This article examines the ‘cultural repertoires’ of neo-Biafran separatist Igbo groups in south-eastern Nigeria, pointing to the ways in which cultural repertoires, narratives and emblems are deployed to forge a separatist ethno-political project in a multi-ethnic state. The neo-Biafran movement reveals the robustness of political resistance and the existence of multiple frameworks through which ethno-nationalist groups resist and challenge extant power structures of the state in the quest for self-determination. The article argues that ethnic groups have the capacity to initiate their own ‘cultural repertoires’ in order to construct group identity, identify forms of external identity (the ‘other’) and shore up the boundaries of their own collective group identity. Myths of origin, narratives of the past, images and symbols are rooted in certain cultural repertoires, and are elaborated, interpreted, invented and reinvented to produce political identities that are complex and fluid in the struggle for political power.

[Interfaces culturelles d'autodétermination et montée du mouvement néo-biafrais au Nigeria.] Cet article examine les « répertoires culturels » des groupes igbo séparatistes du néo-Biafra au sud-est du Nigeria, désignant les façons dont les répertoires culturels, récits et symboles sont développés pour forger un projet séparatiste ethno-politique dans un État multiethnique. Le mouvement néo-biafrais prouve la robustesse de la résistance politique et l'existence de multiples cadres au travers desquels les groupes ethno-nationalistes résistent et défient les structures de pouvoir existantes en quête d'auto-détermination. L'article affirme que les groupes ethniques ont la capacité d'initier leurs propres « répertoires culturels » afin de construire une identité de groupe, identifier des formes d'identité extérieure (« l'autre ») et construire les frontières de leur propre identité collective. Mythe des origines, récits du passé, images et symboles sont ancrés dans des répertoires culturels propres et sont élaborés, interprétés, inventés et réinventés pour produire des identités politiques qui sont complexes et fluides dans la lutte pour le pouvoir politique.

Mots-clés : culture ; politique ; auto-détermination ; identité ethnique ; Igbo ; Nigeria
Genetic influences of sports participation in Portuguese families
Authors: Seabra André F. , Mendonça Denisa M. , Göring Harald H. H. , Thomis Martine A. , Maia José A.
Published: September 2013

To estimate familial aggregation and quantify the genetic and environmental contribution to the phenotypic variation on sports participation (SP) among Portuguese families. The sample consisted of 2375 nuclear families (parents and two offspring each) from different regions of Portugal with a total of 9500 subjects. SP assessment was based on a psychometrically established questionnaire. Phenotypes used were based on the participation in sports (yes/no), intensity of sport, weekly amount of time in SP and the proportion of the year in which a sport was regularly played. Familial correlations were calculated using family correlations (FCOR) in the SAGE software. Heritability was estimated using variance‐components methods implemented in Sequential Oligogenic Linkage Analysis Routines (SOLAR) software. Subjects of the same generation tend to be more similar in their SP habits than the subjects of different generations. In all SP phenotypes studied, adjusted for the effects of multiple covariates, the proportion of phenotypic variance due to additive genetic factors ranged between 40% and 50%. The proportion of variance attributable to environmental factors ranged from 50% for the participation in sports to 60% for intensity of sport. In this large population‐based family study, there was significant familial aggregation on SP. These results highlight that the variation on SP phenotypes have a significant genetic contribution although environmental factors are also important in the familial resemblance of SP.
Cohomological finite generation for restricted Lie superalgebras and finite supergroup schemes
Authors: Drupieski Christopher
Published: September 2013

We prove that the cohomology ring of a finite-dimensional restricted Lie superalgebra over a field of characteristic

p
>
2

p > 2

is a finitely-generated algebra. Our proof makes essential use of the explicit projective resolution of the trivial module constructed by J. Peter May for any graded restricted Lie algebra. We then prove that the cohomological finite generation problem for finite supergroup schemes over fields of odd characteristic reduces to the existence of certain conjectured universal extension classes for the general linear supergroup

G
L
(
m

|

n
)

GL(m|n)

that are similar to the universal extension classes for

G

L
n

GL_n

exhibited by Friedlander and Suslin.
Endosomal acidification by Na+/H+exchanger NHE5 regulates TrkA cell-surface targeting and NGF-induced PI3K signaling
Authors: Diering Graham H. , Numata Yuka , Fan Steven , Church John , Numata Masayuki
Published: September 2013

To facilitate polarized vesicular trafficking and signal transduction, neuronal endosomes have evolved sophisticated mechanisms for pH homeostasis. NHE5 is a member of the Na+/H+exchanger family and is abundantly expressed in neurons and associates with recycling endosomes. Here we show that NHE5 potently acidifies recycling endosomes in PC12 cells. NHE5 depletion by plasmid-based short hairpin RNA significantly reduces cell surface abundance of TrkA, an effect similar to that observed after treatment with the V-ATPase inhibitor bafilomycin. A series of cell-surface biotinylation experiments suggests that anterograde trafficking of TrkA from recycling endosomes to plasma membrane is the likeliest target affected by NHE5 depletion. NHE5 knockdown reduces phosphorylation of Akt and Erk1/2 and impairs neurite outgrowth in response to nerve growth factor (NGF) treatment. Of interest, although both phosphoinositide 3-kinase–Akt and Erk signaling are activated by NGF-TrkA, NGF-induced Akt-phosphorylation appears to be more sensitively affected by perturbed endosomal pH. Furthermore, NHE5 depletion in rat cortical neurons in primary culture also inhibits neurite formation. These results collectively suggest that endosomal pH modulates trafficking of Trk-family receptor tyrosine kinases, neurotrophin signaling, and possibly neuronal differentiation.
Sec16 influences transitional ER sites by regulating rather than organizing COPII
Authors: Bharucha Nike , Liu Yang , Papanikou Effrosyni , McMahon Conor , Esaki Masatoshi , Jeffrey Philip D. , Hughson Frederick M. , Glick Benjamin S.
Published: September 2013

During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has been proposed to play two distinct roles: negatively regulating COPII turnover and organizing COPII assembly at tER sites. We tested these ideas using the yeast Pichia pastoris. Redistribution of Sec16 to the cytosol accelerates tER dynamics, supporting a negative regulatory role for Sec16. To evaluate a possible COPII organization role, we dissected the functional regions of Sec16. The central conserved domain, which had been implicated in coordinating COPII assembly, is actually dispensable for normal tER structure. An upstream conserved region (UCR) localizes Sec16 to tER sites. The UCR binds COPII components, and removal of COPII from tER sites also removes Sec16, indicating that COPII recruits Sec16 rather than the other way around. We propose that Sec16 does not in fact organize COPII. Instead, regulation of COPII turnover can account for the influence of Sec16 on tER sites.
Differential topical susceptibility to TGFβ in intact and injured regions of the epithelium: key role in myofibroblast transition
Authors: Speight Pam , Nakano Hiroyasu , Kelley Thomas J. , Hinz Boris , Kapus András
Published: September 2013

Induction of epithelial–myofibroblast transition (EMyT), a robust fibrogenic phenotype change hallmarked by α-smooth muscle actin (SMA) expression, requires transforming growth factor-β1 (TGFβ) and the absence/uncoupling of intracellular contacts. This suggests that an “injured” epithelium may be topically susceptible to TGFβ. To explore this concept, we use an epithelial wound model in which intact and contact-deprived regions of the same monolayer can be analyzed simultaneously. We show that TGFβ elicits dramatically different responses at these two loci. SMA expression and initially enhanced nuclear Smad3 accumulation followed by Smad3 mRNA and protein down-regulation occur exclusively at the wound. Mechanistically, three transcriptional coactivators whose localization is regulated by cell contact integrity are critical for these local effects. These are myocardin-related transcription factor (MRTF), the driver of the SMA promoter; β-catenin, which counteracts the known inhibitory effect of Smad3 on MRTF and maintains MRTF protein stability and mRNA expression in the wound; and TAZ, a Hippo effector and Smad3 retention factor. Remarkably, active TAZ stimulates the SMA and suppresses the Smad3 promoter, whereas TAZ silencing prevents wound-restricted expression of SMA and loss of Smad3. Such locus-specific reprogramming might play key roles in wound healing and the susceptibility of the injured epithelium to fibrogenesis.
The DNA damage and the DNA replication checkpoints converge at the MBF transcription factor
Authors: Ivanova Tsvetomira , Alves-Rodrigues Isabel , Gómez-Escoda Blanca , Dutta Chaitali , DeCaprio James A. , Rhind Nick , Hidalgo Elena , Ayté José
Published: September 2013

In fission yeast cells, Cds1 is the effector kinase of the DNA replication checkpoint. We previously showed that when the DNA replication checkpoint is activated, the repressor Yox1 is phosphorylated and inactivated by Cds1, resulting in activation of MluI-binding factor (MBF)–dependent transcription. This is essential to reinitiate DNA synthesis and for correct G1-to-S transition. Here we show that Cdc10, which is an essential part of the MBF core, is the target of the DNA damage checkpoint. When fission yeast cells are treated with DNA-damaging agents, Chk1 is activated and phosphorylates Cdc10 at its carboxy-terminal domain. This modification is responsible for the repression of MBF-dependent transcription through induced release of MBF from chromatin. This inactivation of MBF is important for survival of cells challenged with DNA-damaging agents. Thus Yox1 and Cdc10 couple normal cell cycle regulation in unperturbed conditions and the DNA replication and DNA damage checkpoints into a single transcriptional complex.
Invited Commentary: Off-Roading With Social Epidemiology—Exploration, Causation, Translation
Authors: Glymour M. Maria , Osypuk Theresa L. , Rehkopf David H.
Published: September 2013

Population health improvements are the most relevant yardstick against which to evaluate the success of social epidemiology. In coming years, social epidemiology must increasingly emphasize research that facilitates translation into health improvements, with continued focus on macro-level social determinants of health. Given the evidence that the effects of social interventions often differ across population subgroups, systematic and transparent exploration of the heterogeneity of health determinants across populations will help inform effective interventions. This research should consider both biological and social risk factors and effect modifiers. We also recommend that social epidemiologists take advantage of recent revolutionary improvements in data availability and computing power to examine new hypotheses and expand our repertoire of study designs. Better data and computing power should facilitate underused analytic approaches, such as instrumental variables, simulation studies and models of complex systems, and sensitivity analyses of model biases. Many data-driven machine-learning approaches are also now computationally feasible and likely to improve both prediction models and causal inference in social epidemiology. Finally, we emphasize the importance of specifying exposures corresponding with realistic interventions and policy options. Effect estimates for directly modifiable, clearly defined health determinants are most relevant for building translational social epidemiology to reduce disparities and improve population health.
Guidance for implementation of integrated ecosystem assessments: a US perspective
Authors: Levin Phillip S. , Kelble Christopher R. , Shuford Rebecca L. , Ainsworth Cameron , deReynier Yvonne , Dunsmore Rikki , Fogarty Michael J. , Holsman Kirstin , Howell Evan A. , Monaco Mark E. , Oakes Stephanie A. , Werner Francisco
Published: September 2013

Ecosystem-based management (EBM) has emerged as a basic approach for managing human activities in marine ecosystems, with the aim of recovering and conserving marine ecosystems and the services they deliver. Integrated ecosystem assessments (IEAs) further the transition of EBM from principle to practice by providing an efficient, transparent means of summarizing the status of ecosystem components, screening and prioritizing potential risks, and evaluating alternative management strategies against a backdrop of environmental variability. In this paper, we draw upon lessons learned from the US National Oceanic and Atmospheric Administration's IEA programme to outline steps required for IEA implementation. We provide an overview of the conceptual framework for IEAs, the practical constraints that shape the structure of individual IEAs, and the uses and outcomes of IEAs in support of EBM.
Solution structure of the major G-quadruplex formed in the human VEGF promoter in K+: insights into loop interactions of the parallel G-quadruplexes
Authors: Agrawal Prashansa , Hatzakis Emmanuel , Guo Kexiao , Carver Megan , Yang Danzhou
Published: September 2013

Vascular endothelial growth factor (VEGF) proximal promoter region contains a poly G/C-rich element that is essential for basal and inducible VEGF expression. The guanine-rich strand on this tract has been shown to form the DNA G-quadruplex structure, whose stabilization by small molecules can suppress VEGF expression. We report here the nuclear magnetic resonance structure of the major intramolecular G-quadruplex formed in this region in K+ solution using the 22mer VEGF promoter sequence with G-to-T mutations of two loop residues. Our results have unambiguously demonstrated that the major G-quadruplex formed in the VEGF promoter in K+ solution is a parallel-stranded structure with a 1:4:1 loop-size arrangement. A unique capping structure was shown to form in this 1:4:1 G-quadruplex. Parallel-stranded G-quadruplexes are commonly found in the human promoter sequences. The nuclear magnetic resonance structure of the major VEGF G-quadruplex shows that the 4-nt middle loop plays a central role for the specific capping structures and in stabilizing the most favored folding pattern. It is thus suggested that each parallel G-quadruplex likely adopts unique capping and loop structures by the specific middle loops and flanking segments, which together determine the overall structure and specific recognition sites of small molecules or proteins.

LAY SUMMARY: The human VEGF is a key regulator of angiogenesis and plays an important role in tumor survival, growth and metastasis. VEGF overexpression is frequently found in a wide range of human tumors; the VEGF pathway has become an attractive target for cancer therapeutics. DNA G-quadruplexes have been shown to form in the proximal promoter region of VEGF and are amenable to small molecule drug targeting for VEGF suppression. The detailed molecular structure of the major VEGF promoter G-quadruplex reported here will provide an important basis for structure-based rational development of small molecule drugs targeting the VEGF G-quadruplex for gene suppression.
Mp10 and Mp42 from the Aphid Species Myzus persicae Trigger Plant Defenses in Nicotiana benthamiana Through Different Activities
Authors: Rodriguez Patricia A. , Stam Remco , Warbroek Tim , Bos Jorunn I. B.
Published: September 2013

Aphids are phloem-feeding insects that, like other plant parasites, deliver effectors inside their host to manipulate host responses. The Myzus persicae (green peach aphid) candidate effectors Mp10 and Mp42 were previously found to reduce aphid fecundity upon intracellular transient overexpression in Nicotiana benthamiana. We performed functional analyses of these proteins to investigate whether they activate defenses through similar activities. We employed a range of functional characterization experiments based on intracellular transient overexpression in N. benthamiana to determine the subcellular localization of Mp10 and Mp42 and investigate their role in activating plant defense signaling. Mp10 and Mp42 showed distinct subcellular localization in planta, suggesting that they target different host compartments. Also, Mp10 reduced the levels of Agrobacterium-mediated overexpression of proteins. This reduction was not due to an effect on Agrobacterium viability. Transient overexpression of Mp10 but not Mp42 activated jasmonic acid and salicylic acid signaling pathways and decreased susceptibility to the hemibiotrophic plant pathogen Phytophthora capsici. We found that two candidate effectors from the broad-host-range aphid M. persicae can trigger aphid defenses through different mechanisms. Importantly, we found that some (candidate) effectors such as Mp10 interfere with Agrobacterium-based overexpression assays, an important tool to study effector activity and function.
Epidemiology of Blackberry yellow vein associated virus
Authors: Poudel Bindu , Wintermantel William M. , Cortez Arturo A. , Ho Thien , Khadgi Archana , Tzanetakis Ioannis E.
Published: September 2013

Blackberry yellow vein disease is one of the most important diseases of blackberry in the United States. Several viruses are found associated with the symptomology but Blackberry yellow vein associated virus (BYVaV) appears to be the most prevalent of all, leading to the need for a better understanding of its epidemiology. Efficient detection protocols were developed using end-point and quantitative reverse-transcription polymerase chain reaction. A multi-state survey was performed on wild and cultivated blackberry to assess the geographical distribution of the virus. Two whitefly species, Trialeurodes abutilonea and T. vaporariorum, were identified as vectors and 25 plant species were tested as potential BYVaV hosts. The information obtained in this study can be used at multiple levels to better understand and control blackberry yellow vein disease.
Selection, Fitness, and Control of Grape Isolates of Botrytis cinerea Variably Sensitive to Fenhexamid
Authors: Saito Seiya , Cadle-Davidson Lance , Wilcox Wayne F.
Published: September 2013

Of 683 Botrytis cinerea isolates collected from a fungicide-trial vineyard, 31 were classified as putatively resistant to fenhexamid (50% effective concentration [EC50] ≥ 0.1 μg/ml). For the resistant isolates that survived and sporulated in culture, colony expansion and conidial germination frequency was significantly reduced relative to the mean of 30 representative baseline isolates (EC50 = 0.03 μg/ml). Grape berries were inoculated with four isolates representing a range of fenhexamid sensitivities and treated preventively or curatively with fenhexamid concentrations (150 to 600 mg/liter) representing 25 to 100% of the recommended rate. All treatments significantly delayed disease onset and progress caused by isolates with EC50 values of 0.03 and 0.15 μg/ml but provided little to no control of isolates with EC50 values of 0.32 and 62.5 μg/ml. The latter isolate exhibited a previously unreported F427V mutation of ERG27, an enzyme of ergosterol biosynthesis. In a duplex quantitative polymerase chain reaction test, the ratio of pathogen/host DNA increased significantly for 14 days after inoculation of untreated berries with a baseline isolate but declined slightly in berries treated with fenhexamid at 600 mg/liter 1 day post inoculation. In the vineyard, disease control was affected by the number and rate of fenhexamid applications but B. cinerea isolates with EC50 ≥ 0.1 μg/ml were not preferentially selected.
Mycobacterium paragordonae sp. nov., a slowly growing, scotochromogenic species closely related to Mycobacterium gordonae
Authors: Kim Byoung-Jun , Hong Seok-Hyun , Kook Yoon-Hoh , Kim Bum-Joon
Published: September 2013

A previously undescribed, slowly growing, scotochromogenic mycobacterial strain (49061T) was isolated from a patient with pulmonary infections during the hsp65-sequence-based identification of Korean clinical isolates. Its 16S rRNA gene sequence was unique and the phylogenetic analysis based on 16S rRNA gene sequence (1393 bp) placed the organism into the slow-growing

Mycobacterium

group close to

Mycobacterium gordonae

(99.0 % sequence similarity). Growth characteristics and acid-fastness also supported the placement of this species into the genus

Mycobacterium

. Phenotypically, this strain was generally similar to

Mycobacterium gordonae

; however, of particular interest, the optimal growth temperature of strain 49061T was 25–30 °C, and it was not able to grow at 37 °C on 7H10 agar slants. Unique MALDI-TOF MS profiles of lipids, phylogenetic analysis based on another two gene sequences (hsp65 and rpoB) and a low DNA–DNA relatedness (46.52±0.7) strongly supported the taxonomic status of this strain as a representative of a distinct species from

M. gordonae

. It was concluded that the strain represents a novel species for which the name Mycobacterium paragordonae is proposed with the type strain 49061T ( = JCM 18565T = KCTC 29126T).