bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of an Mg‐implanted GaN p–i–n diode
Authors: Greenlee Jordan D. , Anderson Travis J. , Feigelson Boris N. , Hobart Karl D. , Kub Francis J.
Published: July 2015

An Mg‐implanted p–i–n diode was fabricated and characterized. Mg activation was achieved using the multicycle rapid thermal annealing technique with rapid heating pulses up to 1340 °C. The surface of the implanted GaN after annealing was smooth (0.94 nm RMS roughness) with growth steps evident as characterized by atomic force microscopy. The full width at half‐maximum of the implanted GaN E2 Raman mode approaches that of the as‐grown GaN after the annealing process, indicating that the annealing process is able to reverse most of the implantation damage. The Mg‐implanted p–i–n diode exhibits rectification and a low leakage current of 0.11 μA cm−2 at a bias of −10 V. Under forward bias, light emission was observed from the p–i–n diode. The implantation and activation of Mg in a GaN‐based device, demonstrated for the first time in this research, is a key enabling step for future optoelectronic and power electronic devices.

Current–voltage characteristics of the Mg‐implanted p–i–n diode with an inset of the device schematic.
Simplified method for the evaluation of the reverse dark current–voltage characteristic of thin film devices
Authors: Rubinelli Francisco A. , De Greef Marcelo
Published: July 2015

An algorithm that simplifies the evaluation of the reverse dark current–voltage (J–V) characteristic of semiconductor thin film devices is presented. This algorithm, recognized with the symbols “0KRDA”, is an approximation of the SRH formalism that can be used when the dangling bond density is modeled with either the Uniform Density Model or with the Defect Pool Model. The 0KRDA is designed to replace the 0K‐Simmons–Taylor approximation (0KSTA) in reversed biased junctions operating under dark conditions. The dependence of the current density J with respect to the applied voltage V predicted with SRH formalism is well replicated by the 0KRDA. The small differences obtained in the calculated reverse dark currents can be removed by neglecting the contribution of gap states with energies closer than kT/5 to the intrinsic trap level. The transport physic controlling the shape of reverse dark J–V curves of thin film devices can be more easily visualized with the 0KRDA.
Study of the structural and magnetic properties of Fe‐doped ZnO
Authors: Salah Oudjertli , Rachid Bensalem , Safia Alleg , Suñol J. J. , Bououdina Mohamed , Ibrir Miloud
Published: July 2015

In this work we study the ZnO powder nanoparticles mechanically alloyed doped with iron to investigate the structural, microstructural and magnetic properties using X‐ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM). The ZnO starting pure powder exhibited a hexagonal crystal structure with space group P63mc of ZnO, however, with the introduction of 1% Fe in the ZnO milled powder, the hexagonal ZnO phase remained unchanged, whereas the microstructural parameters were subject to significant variations due to the introduction of Fe atoms into the ZnO hexagonal matrix to replace oxygen ones. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of climate change on urban heat island effect and extreme temperatures: a case‐study
Authors: Sachindra D. A. , Ng A. W. M. , Muthukumaran S. , Perera B. J. C.
Published: July 2015

This study investigated the impacts of climate change on the urban heat island (UHI) and the number of very hot (maximum temperature >35°C) and very cold days (minimum temperature <5°C) in the central business district (CBD) of Melbourne city in Australia. A station located in Laverton (less urbanised area), which is 17 km southwest of Melbourne CBD, was selected as the reference station for the computation of UHI intensity in Melbourne CBD. Using daily minimum/maximum temperatures at the two stations, nocturnal/diurnal UHI intensities in Melbourne CBD were computed for the period 1952–2010. It was found that in Melbourne CBD, nocturnal UHI intensities show a clear rising trend over the period 1952–2010 unlike the diurnal UHI intensities. For the analysis of nocturnal UHI intensities in Melbourne CBD, under changing climate, for each calendar month statistical models based on the gene expression programming (GEP) technique were developed for downscaling general‐circulation model (GCM) outputs to monthly average minimum temperature at Melbourne CBD and Laverton. Using the outputs of HadCM3, GFDL2.0 and ECHAM5 pertaining to the A2 greenhouse gas emission scenario on the downscaling models, projections of monthly average minimum temperature were produced for the two stations over the period 2000–2099. In each season, at both stations, the ensemble average of monthly minimum temperature gradually increased over the period 2000–2099. The ensemble‐average UHI intensity in Melbourne CBD projected into the future was higher for all seasons in comparison to that of period 1952–1971. Downscaling models based on the GEP technique were developed for each calendar month for projecting the number of very hot days in November–March and very cold days in May–September in Melbourne CBD. It was found that, in the future, summer weather will spread to early autumn, and winter weather will move to early spring, in Melbourne CBD.
Calculations of electron inelastic mean free paths. X. Data for 41 elemental solids over the 50 eV to 200 keV range with the relativistic full Penn algorithm
Authors: Shinotsuka H. , Tanuma S. , Powell C. J. , Penn D. R.
Published: July 2015

We have calculated inelastic mean free paths (IMFPs) for 41 elemental solids (Li, Be, graphite, diamond, glassy C, Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ge, Y, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Cs, Gd, Tb, Dy, Hf, Ta, W, Re, Os, Ir, Pt, Au, and Bi) for electron energies from 50 eV to 200 keV. The IMFPs were calculated from measured energy loss functions for each solid with a relativistic version of the full Penn algorithm. The calculated IMFPs could be fitted to a modified form of the relativistic Bethe equation for inelastic scattering of electrons in matter for energies from 50 eV to 200 keV. The average root‐mean‐square (RMS) deviation in these fits was 0.68%. The IMFPs were also compared with IMFPs from a relativistic version of our predictive Tanuma, and Powell and Penn (TPP‐2M) equation that was developed from a modified form of the relativistic Bethe equation. In these comparisons, the average RMS deviation was 11.9% for energies between 50 eV and 200 keV. This RMS deviation is almost the same as that found previously in a similar comparison for the 50 eV to 30 keV range (12.3%). Relatively large RMS deviations were found for diamond, graphite, and cesium as in our previous comparisons. If these three elements were excluded in the comparisons, the average RMS deviation was 8.9% between 50 eV and 200 keV. The relativistic TPP‐2M equation can thus be used to estimate IMFPs in solid materials for energies between 50 eV and 200 keV. We found satisfactory agreement between our calculated IMFPs and those from recent calculations and from measurements at energies of 100 and 200 keV. Copyright © 2015 John Wiley & Sons, Ltd.
Glaciers and climate change: narratives of ruined futures
Authors: Jackson M
Published: July 2015

Across global environmental change research, glaciers are depicted as rapidly disappearing. This review identifies and problematizes the prevalence of a glacier‐ruins narrative in artistic, performative, cinematic, and other humanities‐based representations of glacier–climate discourse and perceptions. A glacier‐ruins narrative is understood as a narrative about glaciers that tends to overlook the existing state of a glacier and/or glacier systems and speaks instead to imagined states of loss. Five examples are reviewed and exemplify this glacier‐ruins narrative: the work of well‐known American landscape painter Diane Burko, conceptual artist Kitty Von‐Sometime's 2014 performance, ice installations by Olafur Eliasson and Minik Rosing, the documentary filmChasing Ice, and the National Park Service's Exit Glacier display within south‐central Alaska's Kenai Fjords National Park. While a glacier‐ruins narrative is present throughout various academic disciplines engaging with global environmental change research, this review focuses primarily on the humanities, largely in response to multiple scholars' calls for the increased role of the humanities in global environmental change discourse. This review suggests that the practice of climate change reductionism is equally prevalent in the humanities as it is in the natural and social sciences. It argues that narrating glaciers as climate change ruins normalizes and predetermines a glacier‐free world not yet in existence while reducing the range of imaginable climate change‐influenced futures.WIREs Clim Change2015, 6:479–492. doi: 10.1002/wcc.351

This article is categorized under:

Climate, History, Society, Culture > Ideas and Knowledge

Trans‐Disciplinary Perspectives > Humanities and the Creative Arts
Confined Raman Scattering – Easy Access to the Surface Phonons of Specific Crystalline Solids
Authors: Werheit Helmut , Filipov Volodimir , Shitsevalova Natalya
Published: July 2015

An easily feasible method to measure surface phonons of specific crystalline solids is described. Special experimental conditions allow confining Raman scattering to the surface region of crystals, while the contribution of bulk scattering to the spectra is largely excluded. Such conditions exist for example in the case of hexaborides, using FT Raman spectroscopy with a commercial spectrometer with ND:YAG laser excitation. We show results obtained on LaB6, SmB6 and boron carbide. The surface phonon spectra of LaB6 are analyzed by comparing them with bulk spectra and discussed in comparison with results of other experimental methods and theoretical calculations.
Defining Our Clinical Practice: The Identification of Genetic Counseling Outcomes Utilizing the Reciprocal Engagement Model
Authors: Redlinger‐Grosse Krista , Veach Patricia McCarthy , Cohen Stephanie , LeRoy Bonnie S. , MacFarlane Ian M. , Zierhut Heather
Published: July 2015

The need for evidence‐based medicine, including comparative effectiveness studies and patient‐centered outcomes research, has become a major healthcare focus. To date, a comprehensive list of genetic counseling outcomes, as espoused by genetic counselors, has not been established and thus, identification of outcomes unique to genetic counseling services has become a priority for the National Society of Genetic Counselors (NSGC). The purpose of this study was to take a critical first step at identifying a more comprehensive list of genetic counseling outcomes. This paper describes the results of a focus group study using the Reciprocal‐Engagement Model (REM) as a framework to characterize patient‐centered outcomes of genetic counseling clinical practice. Five focus groups were conducted with 27 peer nominated participants who were clinical genetic counselors, genetic counseling program directors, and/or outcomes researchers in genetic counseling. Members of each focus group were asked to identify genetic counseling outcomes for four to five of the 17 goals of the REM. A theory‐driven, thematic analysis of focus group data yielded 194 genetic counseling outcomes across the 17 goals. Participants noted some concerns about how genetic counseling outcomes will be measured and evaluated given varying stakeholders and the long‐term nature of genetic concerns. The present results provide a list of outcomes for use in future genetic counseling outcomes research and for empirically‐supported clinical interventions.
Vergleichende Untersuchung der Zentrale-Orte-Konzepte in den Ländern und Empfehlungen zu ihrer Weiterentwicklung
Authors: Greiving Stefan , Flex Florian , Terfrüchte Thomas
Published: July 2015

Central place concepts are an inherent part of all regional plans of the German federal states (the ‘Länder’). These concepts have become increasingly important because regional plans need to be adapted to recent and future demographic changes in order to ensure an adequate provision of services of general interest. This paper analyses the current central place concepts of the Länder and gives recommendations for their further development.

The analysis shows that the Länder have developed different approaches in regard to central place concepts, both in terms of definitions, threshold levels of population and accessibility and also their function for guiding future regional development.

The paper gives recommendations on how to improve central place concepts and related plan approval procedures. Policy makers and planning authorities should define and seek political approval for overarching goals, from which key analytical indicators would be derived. These indicators should then be used for an empirical analysis, which would finally allow designating central places and their respective functions. Of course, the underlying methodology should be explained in detail within each regional plan.

A central place should not be designated on the basis of its current facilities and services, but on the basis of the specific demographic and spatial characteristics and requirements of the surrounding region. Thus two cities with similar central facilities could nevertheless be handled differently by a central place concept because their respective hinterlands have different needs for central places.
Robustness of personal rankings: the Handelsblatt example
Authors: Lorenz Daniela , Löffler Andreas
Published: July 2015

In the last years,Handelsblatthas published several rankings of business economists from German, Swiss and Austrian research institutions based on their journal publication output. These rankings have a strong influence on the academic profession. We scrutinize theHandelsblattmethodology by examining the effect the rankings’ underlying algorithms and assumptions have on the scores and ranks of individual researchers. In doing so, we clarify how robust the result is with respect to these internal parameters. Since the parameters used byHandelsblattare not scientifically substantiated but defined ad hoc, this question is of great importance. For each parameter variation, we provide several robustness measures for both theHandelsblattlife’s work ranking and theHandelsblattrecent research performance ranking. E.g., if one applies a weighting scheme that lays more emphasis on first tier journal publications such that the weight of a particular category is always double of the weight of the next lower category, rank correlations based on all researchers in both personal rankings exceed 80 %. However, if one solely considers the top 25 performing researchers rank correlations fall below 50 and 20 % of researchers even drop out of this top group. Further research as well as the discussion in the academic community should clarify whether these correlations verify the robustness of the ranking or manifest the opposite.
Elliptical pore regularisation of the inverse problem for microstructured optical fibre fabrication
Authors: Buchak Peter , Crowdy Darren G. , Stokes Yvonne M. , Ebendorff-Heidepriem Heike
Published: July 2015

A mathematical model is presented describing the deformation, under the combined effects of surface tension and draw tension, of an array of channels in the drawing of a broad class of slender viscous fibres. The process is relevant to the fabrication of microstructured optical fibres, also known as MOFs or holey fibres, where the pattern of channels in the fibre plays a crucial role in guiding light along it. Our model makes use of two asymptotic approximations, that the fibre is slender and that the cross-section of the fibre is a circular disc with well-separated elliptical channels that are not too close to the outer boundary. The latter assumption allows us to make use of a suitably generalised ‘elliptical pore model (EPM)’ introduced previously by one of the authors (Crowdy, J. Fluid Mech., vol. 501, 2004, pp. 251–277) to quantify the axial variation of the geometry during a steady-state draw. The accuracy of the elliptical pore model as an approximation is tested by comparison with full numerical simulations. Our model provides a fast and accurate reduction of the full free-boundary problem to a coupled system of nonlinear ordinary differential equations. More significantly, it also allows a regularisation of an important ill-posed inverse problem in MOF fabrication: how to find the initial preform geometry and the experimental parameters required to draw MOFs with desired cross-plane geometries.
Negation through reduplication and tone: implications for the Lexical Functional Grammar/Paradigm Function Morphology interface
Authors: BOND OLIVER
Published: July 2015

Morphological marking of negation through verbal reduplication and tone is a typologically rare phenomenon attested in Eleme (Niger-Congo; Nigeria). Using Lexical Functional Grammar (LFG) and Paradigm Function Morphology (PFM) to model first-hand data, I argue that reduplication is not a direct exponent of negation in Eleme, but an asemantic morphomic process, indirectly associated with the presence of a negative polarity feature in LFG’s m(orphological)-structure. While negative verb forms of this kind are typologically unusual, the data can be explained by independently motivated morphology-internal principles. The empirical facts thereby provide support for an m-structure, characterised by its own principles and rules, which interfaces with a bifurcated lexicon that separates content from form.
The influence of spelling on the production and storage of words with allophonic variants of /h/ in Korean
Authors: HAN JEONG-IM , CHOI TAE-HWAN
Published: July 2015

This study examined the role of orthography in the production and storage of spoken words. Korean speakers learned novel Korean words with potential variants of /h/, including [ɦ] and ø. They were provided with the same auditory stimuli but with varying exposure to spelling. One group was presented with the letter for ø (<ㅇ>), the second group, the letter for [ɦ] (<ㅎ>), and the third group, auditory input only. In picture-naming tasks, the participants presented with <ㅇ> produced fewer words with [ɦ] than those presented with <ㅎ>. In a spelling recall task, the participants who were not exposed to spelling displayed various types of spellings for variants, but after exposure to spelling, they began to produce spellings as provided in the task. These results suggest that orthographic information influences the production of words via an offline restructuring of the phonological representation.
Communities of practice in the conservatory: learning with a professional musician
Authors: Virkkula Esa
Published: July 2015

This article examines the sociocultural learning of popular and jazz music in communities of practice as part of secondary vocational music education in a Finnish conservatory. The research is based on performance workshops which were implemented as a joint effort between professional musicians and music students. These workshops are suggested as a method of utilising communities of practice. Research outcomes show that the workshops include opportunities for learning and developing musicianship on many levels. The potential of sociocultural learning should be recognised in music schools and teachers should develop learning environments which utilise it. Learning from playing experiences and from the evaluation of learning outcomes are largely the students' responsibility who require autonomy, initiative, the ability to solve problems and collaborate, and a readiness to reflect on experiences.
The International Convention on the Prevention of Odious Agreements: A Human Rights-Based Mechanism to Avoid Odious Debts
Authors: SCHNEIDER FRIEDRICH BENJAMIN
Published: July 2015

There is a lively discussion as to whether debts incurred by despotic regimes and used to the detriment of the population are legally valid. This article gives a brief introduction to the concept of so-called odious debts and argues that a legal solution is not only desirable, but feasible. Subsequently, international human rights are identified as the missing link between the behaviour of the debtor state and the assessment of individual debts. Consequently, a human rights-based mechanism for the prevention of odious agreements is developed, based on an international convention annexed to this article. The convention provides that a state is classified as odious debts-prone if it is responsible for serious and systematic violations of human rights or international humanitarian law, or if its public sector is governed by severe and systemic corruption. Agreements concluded with an odious debts-prone state are void, unless the agreement complies with principles of responsible contracting as developed in this article. Finally, the scope of application of the convention and possible state parties are specified.
The pandemic potential of avian influenza A(H7N9) virus: a review
Authors: TANNER W. D. , TOTH D. J. A. , GUNDLAPALLI A. V.
Published: July 2015

In March 2013 the first cases of human avian influenza A(H7N9) were reported to the World Health Organization. Since that time, over 650 cases have been reported. Infections are associated with considerable morbidity and mortality, particularly within certain demographic groups. This rapid increase in cases over a brief time period is alarming and has raised concerns about the pandemic potential of the H7N9 virus. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. This paper reviews what is currently known about each of these factors with respect to avian influenza A(H7N9). Currently, sustained human-to-human transmission of H7N9 has not been reported; however, population immunity to the virus is considered very low, and the virus has significant ability to cause human disease. Several statistical and geographical modelling studies have estimated and predicted the spread of the H7N9 virus in humans and avian species, and some have identified potential risk factors associated with disease transmission. Additionally, assessment tools have been developed to evaluate the pandemic potential of H7N9 and other influenza viruses. These tools could also hypothetically be used to monitor changes in the pandemic potential of a particular virus over time.
Geochemical evidence of different sources of long-period seismic events at Deception volcano, South Shetland Islands, Antarctica
Authors: Padrón Eleazar , Hernández Pedro A. , Carmona Enrique , Pérez Nemesio M. , Melián Gladys , Sumino Hirochika , Almendros Javier , Kusakabe Minoru , Wakita Hiroshi , Padilla Germán D.
Published: July 2015

This is the first detailed analysis of a CO2diffuse degassing time series from Deception volcano, South Shetland Islands, Antarctica, performed during an episode of anomalously high long-period (LP) seismicity. Diffuse CO2emissions measured by an automatic geochemical station between 7 December 2009 and 13 February 2010 showed an excellent temporal agreement with the LP seismicity in December 2009. The absence of such a temporal correlation with the second burst of seismicity that occurred in late January 2010 suggests a different source for this LP activity. This was confirmed by analysis of seismic array data. The LP seismicity observed during December 2009 was caused by fluid-driven cracks that originated from pressure fluctuations in the volcano-hydrothermal systems beneath Deception volcano that were probably caused by a deep injection of undegassed magma before December 2009. The diffuse CO2degassing data have provided evidence of the activation of at least two different sources of seismicity during the study period at Deception volcano.
Solar Surface Anisotropy effect on the Magnetic Field
Authors: Bommier Véronique
Published: July 2015

Within the literature there are at least 15 references indicating that the horizontal magnetic flux does not exactly balance vertical flux in sunspots, leading to the surprising result that div$\vec{B}$would depart from zero. Intuitively, this has to be related to the stratification at the surface of the star, due to which horizontal and vertical typical lengths are different. This surface anisotropy results from gravity, but how does gravity influence the magnetic field? To answer this question, a scenario has been proposed in two recent publications, based on anisotropic Debye shielding. The presentation reported in this paper was devoted to investigate the possibility and causes of a non-zero div$\vec{B}$. A scaling law associated with the anisotropy is able to reestablish the nullity of div$\vec{B}$, which would lead to a renewed MHD in the solar photosphere layer. An eventual observation in the laboratory is also reported.
Atomic Scattering Polarization. Observations, Modeling, Predictions
Authors: Bueno J. Trujillo , Alemán T. Del Pino , Belluzzi L.
Published: July 2015

This paper highlights very recent advances concerning the identification of new mechanisms that introduce polarization in spectral lines, which turn out to be key for understanding some of the most enigmatic scattering polarization signals of the solar visible spectrum. We also show a radiative transfer prediction on the scattering polarization pattern across the Mg iih & k lines, whose radiation can only be observed from space.
Chromospheric diagnosis with forward scattering polarization
Authors: Carlin E. S.
Published: July 2015

Is it physically feasible to perform the chromospheric diagnosis using spatial maps of scattering polarization at the solar disk center? To investigate it we synthesized polarization maps (in 8542 Å) resulting from MHD solar models and NLTE radiative transfer calculations that consider Hanle effect and vertical macroscopic motions. After explaining the physical context of forward scattering and presenting our results, we arrive at the definition of Hanle polarity inversion lines. We show how such features can give support for a clearer chromospheric diagnosis in which the magnetic and dynamic effects in the scattering polarization could be disentangled.
New Optics for Astronomical Polarimetry
Authors: Baur Tom
Published: July 2015

There is a variety of new polarization optics that can be employed for polarimetry and for polarization control. Many are enabled by new materials including polymers and liquid crystals. We survey here these and other relatively new devices and components available commercially that open new possibilities for astronomers.
Parallelization of the SIR code for the investigation of small-scale features in the solar photosphere
Authors: Thonhofer Stefan , Rubio Luis R. Bellot , Utz Dominik , Hanslmeier Arnold , Jurçák Jan
Published: July 2015

Magnetic fields are one of the most important drivers of the highly dynamic processes that occur in the lower solar atmosphere. They span a broad range of sizes, from large- and intermediate-scale structures such as sunspots, pores and magnetic knots, down to the smallest magnetic elements observable with current telescopes. On small scales, magnetic flux tubes are often visible as Magnetic Bright Points (MBPs). Apart from simple V/I magnetograms, the most common method to deduce their magnetic properties is the inversion of spectropolarimetric data. Here we employ the SIR code for that purpose. SIR is a well-established tool that can derive not only the magnetic field vector and other atmospheric parameters (e.g., temperature, line-of-sight velocity), but also their stratifications with height, effectively producing 3-dimensional models of the lower solar atmosphere. In order to enhance the runtime performance and the usability of SIR we parallelized the existing code and standardized the input and output formats. This and other improvements make it feasible to invert extensive high-resolution data sets within a reasonable amount of computing time. An evaluation of the speedup of the parallel SIR code shows a substantial improvement in runtime.
Circumstellar Polarimetry
Authors: Magalhães A. M. , Carciofi A. C. , Seriacopi D. B.
Published: July 2015

Starlight polarization provides insight into the physical mechanisms in and around the source as well as its geometry, whether or not the source is resolved. In this talk we will review mechanisms that polarize light in stellar envelopes. The observations and modeling can be used to probe the physics of the circumstellar environment as well as its relation to the ambient interstellar environment.
Probing disk inhomogeneities using spectropolarimetry in the extreme binary epsilon Aurigae
Authors: Geise Kathleen , Stencel Robert
Published: July 2015

The ϵ Aurigae system is a single–line spectroscopic binary system that consists of a variable F0 supergiant star and an occulting disk surrounding an unseen object, probably a B star. The eclipse occurs every 27 years and lasts for almost 2 years. Spectral features attributed to the disk exhibit line shifts due to the rotation of the disk that are easily observed in spectra. We obtained 50+ epochs of high dispersion optical spectropolarimetric data from the ESPaDOnS instrument at the Canada–France–Hawaii Telescope before, during, and after the most recent eclipse (2009–2011). We found numerous 3–sigma (or greater) linear polarization features in the spectra and associated these with atomic absorption features also present in the spectra. We observed dramatic changes to polarization and position angles with time during eclipse, particularly around 3rd contact. The increased polarization could be due to a localized increased number of scatterers.
Three-dimensional simulations of scattering polarization and the Hanle effect in MHD chromospheric models
Authors: Štěpán J.
Published: July 2015

Scattering line polarization and the Hanle effect are among the most important mechanisms for diagnostics of the solar and stellar atmospheres. The fact that real stellar atmospheres are horizontally inhomogeneous makes the spectral synthesis and interpretation very challenging because the effect of thermodynamic fluctuations on spectral line polarization is entangled with the action of magnetic fields. This applies to the spatially resolved as well as to the averaged spectra. The necessary step towards the interpretation of such spectra is to study the line formation in sufficiently realistic 3D MHD models and compare the synthetic spectra with observations. This paper gives an overview of recent progress in the field of 3D NLTE synthesis of polarized spectral lines resulting from investigations with the radiative transfer code PORTA.
2015 AGU Union Medal, Award, and Prize Recipients Announced
Authors: Leinen Margaret , Mukasa Sam
Published: July 2015

The world's largest organization of Earth and space scientists honors 25 exceptional scientists and journalists.
Mitochondrial complex II is a source of the reserve respiratory capacity that is regulated by metabolic sensors and promotes cell survival
Authors: Pfleger J , He M , Abdellatif M
Published: July 2015

The survival of a cell depends on its ability to meet its energy requirements. We hypothesized that the mitochondrial reserve respiratory capacity (RRC) of a cell is a critical component of its bioenergetics that can be utilized during an increase in energy demand, thereby, enhancing viability. Our goal was to identify the elements that regulate and contribute to the development of RRC and its involvement in cell survival. The results show that activation of metabolic sensors, including pyruvate dehydrogenase and AMP-dependent kinase, increases cardiac myocyte RRC via a Sirt3-dependent mechanism. Notably, we identified mitochondrial complex II (cII) as a target of these metabolic sensors and the main source of RRC. Moreover, we show that RRC, via cII, correlates with enhanced cell survival after hypoxia. Thus, for the first time, we show that metabolic sensors via Sirt3 maximize the cellular RRC through activating cII, which enhances cell survival after hypoxia.
Structural prerequisites for G-protein activation by the neurotensin receptor
Authors: Krumm Brian E. , White Jim F. , Shah Priyanka , Grisshammer Reinhard
Published: July 2015

We previously determined the structure of neurotensin receptor NTSR1 in an active-like conformation with six thermostabilizing mutations bound to the peptide agonist neurotensin. This receptor was unable to activate G proteins, indicating that the mutations restricted NTSR1 to relate agonist binding to G-protein activation. Here we analyse the effect of three of those mutations (E166A3.49, L310A6.37, F358A7.42) and present two structures of NTSR1 able to catalyse nucleotide exchange at Gα. The presence of F3587.42 causes the conserved W3216.48 to adopt a side chain orientation parallel to the lipid bilayer sealing the collapsed Na+ ion pocket and linking the agonist with residues in the lower receptor part implicated in GPCR activation. In the intracellular receptor half, the bulkier L3106.37 side chain dictates the position of R1673.50 of the highly conserved D/ERY motif. These residues, together with the presence of E1663.49 provide determinants for G-protein activation by NTSR1.
Flotillin-2 promotes metastasis of nasopharyngeal carcinoma by activating NF-κB and PI3K/Akt3 signaling pathways
Authors: Liu Jie , Huang Wei , Ren Caiping , Wen Qiuyuan , Liu Weidong , Yang Xuyu , Wang Lei , Zhu Bin , Zeng Liang , Feng Xiangling , Zhang Chang , Chen Huan , Jia Wei , Zhang Lihua , Xia Xiaomeng , Chen Yuxiang
Published: July 2015

Lipid raft proteins have been confirmed to be important in cell signal transduction. Some reports have shown that the aberrant expression of lipid raft proteins is associated with malignant phenotypes in some cancers. However, the role of the lipid raft protein flotillin-2 (Flot-2) in nasopharyngeal carcinoma (NPC) remains to be comprehensively characterized. Here, overexpression of Flot-2 in NPC tissues and cell lines was detected by immunostaining and Flot-2 expression was found to be positively associated with NPC metastasis. Furthermore, inhibiting Flot-2 expression impaired the malignancy of the highly metastatic NPC cell line 5-8F by constraining its growth and proliferation, mobility and migration and decreasing the capacity of 5-8F cells to metastasize in nude mice. In contrast, forced overexpression of Flot-2 increased the malignancy of 6-10B, a non-metastatic NPC cell line that weakly expresses Flot-2. Moreover, in 5-8F-shFlot-2 cells, which have inhibited Flot-2 expression, the NF-κB and PI3K/Akt3 pathways were inactivated. Subsequently, MMPs expression were decreased and Foxo1 activity was increased. In addition, enhanced NF-κB and PI3K/Akt3 activities were observed in Flot-2 overexpressing 6-10B cells. Thus, Flot-2 exerts a pro-neoplastic role in NPC and is involved in tumor progression and metastasis. Moreover, Flot-2 exerts its role through NF-κB and PI3K/Akt3 signaling.
Comparison of Therapeutic Effect of Recombinant Tissue Plasminogen Activator by Treatment Time after Onset of Acute Ischemic Stroke
Authors: Wang Hai-rong , Chen Miao , Wang Fei-long , Dai Li-hua , Fei Ai-hua , Liu Jia-fu , Li Hao-jun , Shen Sa , Liu Ming , Pan Shu-ming
Published: July 2015

We aimed to compare the therapeutic effect of recombinant tissue plasminogen activator (rt-PA) administered at different time windows within the first 6 hours after onset of acute ischemic stroke (AIS). A retrospective analysis was performed of data collected from 194 patients who received rt-PA thrombolysis within 4.5 hours after AIS onset and from 29 patients who received rt-PA thrombolysis between 4.5–6 hours after AIS onset. The National Institutes of Health Stroke Scale (NIHSS) scores were statistically decreased in both groups (P < 0.05) at 24 hours and 7 days after onset. There was no statistical difference in the modified Rankin score or mortality at day 90 after treatment between the two groups (P > 0.05). In conclusion, AIS patients who received rt-PA treatment between 4.5–6 hours after onset were similar in therapeutic efficacy to those who received rt-PA within 4.5 hours after onset. Our results suggest that intravenous thrombolytic therapy for AIS within 4.5–6 hours after onset is effective and safe.
Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling
Authors: Zhang Jack Y. , Hwang Jinwoo , Isaac Brandon J. , Stemmer Susanne
Published: July 2015

Variable-angle high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy is developed for precise and accurate determination of three-dimensional (3D) dopant atom configurations. Gd-doped SrTiO3 films containing Sr columns containing zero, one, or two Gd dopant atoms are imaged in HAADF mode using two different collection angles. Variable-angle HAADF significantly increases both the precision and accuracy of 3D dopant profiling. Using image simulations, it is shown that the combined information from the two detectors reduces the uncertainty in the dopant depth position measurement and can uniquely identify certain atomic configurations that are indistinguishable with a single detector setting. Additional advances and applications are discussed.
14-3-3ζ deficient mice in the BALB/c background display behavioural and anatomical defects associated with neurodevelopmental disorders
Authors: Xu Xiangjun , Jaehne Emily J. , Greenberg Zarina , McCarthy Peter , Saleh Eiman , Parish Clare L. , Camera Daria , Heng Julian , Haas Matilda , Baune Bernhard T. , Ratnayake Udani , Buuse Maarten van den , Lopez Angel F. , Ramshaw Hayley S. , Schwarz Quenten
Published: July 2015

Sequencing and expression analyses implicate 14-3-3ζ as a genetic risk factor for neurodevelopmental disorders such as schizophrenia and autism. In support of this notion, we recently found that 14-3-3ζ−/− mice in the Sv/129 background display schizophrenia-like defects. As epistatic interactions play a significant role in disease pathogenesis we generated a new congenic strain in the BALB/c background to determine the impact of genetic interactions on the 14-3-3ζ−/− phenotype. In addition to replicating defects such as aberrant mossy fibre connectivity and impaired spatial memory, our analysis of 14-3-3ζ−/− BALB/c mice identified enlarged lateral ventricles, reduced synaptic density and ectopically positioned pyramidal neurons in all subfields of the hippocampus. In contrast to our previous analyses, 14-3-3ζ−/− BALB/c mice lacked locomotor hyperactivity that was underscored by normal levels of the dopamine transporter (DAT) and dopamine signalling. Taken together, our results demonstrate that dysfunction of 14-3-3ζ gives rise to many of the pathological hallmarks associated with the human condition. 14-3-3ζ-deficient BALB/c mice therefore provide a novel model to address the underlying biology of structural defects affecting the hippocampus and ventricle and cognitive defects such as hippocampal-dependent learning and memory.
Stomatal closure is induced by hydraulic signals and maintained by ABA in drought-stressed grapevine
Authors: Tombesi Sergio , Nardini Andrea , Frioni Tommaso , Soccolini Marta , Zadra Claudia , Farinelli Daniela , Poni Stefano , Palliotti Alberto
Published: July 2015

Water saving under drought stress is assured by stomatal closure driven by active (ABA-mediated) and/or passive (hydraulic-mediated) mechanisms. There is currently no comprehensive model nor any general consensus about the actual contribution and relative importance of each of the above factors in modulating stomatal closurein planta. In the present study, we assessed the contribution of passive (hydraulic) vs active (ABA mediated) mechanisms of stomatal closure inV. viniferaplants facing drought stress. Leaf gas exchange decreased progressively to zero during drought and embolism-induced loss of hydraulic conductance in petioles peaked to ~50% in correspondence with strong daily limitation of stomatal conductance. Foliar ABA significantly increased only after complete stomatal closure had already occurred. Rewatering plants after complete stomatal closure and after foliar ABA reached maximum values did not induced stomatal re-opening, despite embolism recovery and water potential rise. Our data suggest that in grapevine stomatal conductance is primarily regulated by passive hydraulic mechanisms. Foliar ABA apparently limits leaf gas exchange over long-term, also preventing recovery of stomatal aperture upon rewatering, suggesting the occurrence of a mechanism of long-term down-regulation of transpiration to favor embolism repair and preserve water under conditions of fluctuating water availability and repeated drought events.
2D map projections for visualization and quantitative analysis of 3D fluorescence micrographs
Authors: Sendra G. Hernán , Hoerth Christian H. , Wunder Christian , Lorenz Holger
Published: July 2015

We introduce Map3-2D, a freely available software to accurately project up to five-dimensional (5D) fluorescence microscopy image data onto full-content 2D maps. Similar to the Earth’s projection onto cartographic maps, Map3-2D unfolds surface information from a stack of images onto a single, structurally connected map. We demonstrate its applicability for visualization and quantitative analyses of spherical and uneven surfaces in fixed and dynamic live samples by using mammalian and yeast cells and giant unilamellar vesicles. Map3-2D software is available at http://www.zmbh.uni-heidelberg.de//Central_Services/Imaging_Facility/Map3-2D.html.
Genome-wide high-throughput SNP discovery and genotyping for understanding natural (functional) allelic diversity and domestication patterns in wild chickpea
Authors: Bajaj Deepak , Das Shouvik , Badoni Saurabh , Kumar Vinod , Singh Mohar , Bansal Kailash C. , Tyagi Akhilesh K. , Parida Swarup K.
Published: July 2015

We identified 82489 high-quality genome-wide SNPs from 93 wild and cultivated Cicer accessions through integrated reference genome- and de novo-based GBS assays. High intra- and inter-specific polymorphic potential (66–85%) and broader natural allelic diversity (6–64%) detected by genome-wide SNPs among accessions signify their efficacy for monitoring introgression and transferring target trait-regulating genomic (gene) regions/allelic variants from wild to cultivated Cicer gene pools for genetic improvement. The population-specific assignment of wild Cicer accessions pertaining to the primary gene pool are more influenced by geographical origin/phenotypic characteristics than species/gene-pools of origination. The functional significance of allelic variants (non-synonymous and regulatory SNPs) scanned from transcription factors and stress-responsive genes in differentiating wild accessions (with potential known sources of yield-contributing and stress tolerance traits) from cultivated desi and kabuli accessions, fine-mapping/map-based cloning of QTLs and determination of LD patterns across wild and cultivated gene-pools are suitably elucidated. The correlation between phenotypic (agromorphological traits) and molecular diversity-based admixed domestication patterns within six structured populations of wild and cultivated accessions via genome-wide SNPs was apparent. This suggests utility of whole genome SNPs as a potential resource for identifying naturally selected trait-regulating genomic targets/functional allelic variants adaptive to diverse agroclimatic regions for genetic enhancement of cultivated gene-pools.
Genome-wide construction of a series of designed segmental aneuploids in Saccharomyces cerevisiae
Authors: Natesuntorn Waranya , Iwami Kotaro , Matsubara Yuki , Sasano Yu , Sugiyama Minetaka , Kaneko Yoshinobu , Harashima Satoshi
Published: July 2015

Segmental aneuploidy can play an important role in environmental adaptation. However, study of segmental aneuploids is severely hampered by the difficulty of creating them in a designed fashion. Here, we describe a PCR-mediated chromosome duplication (PCDup) technology that enables the generation of segmental aneuploidy at any desired chromosomal region in Saccharomyces cerevisiae. We constructed multiple strains harboring 100 kb to 200 kb segmental duplications covering the whole of the S. cerevisiae genome. Interestingly, some segmental aneuploidies confer stress tolerance, such as to high temperature, ethanol and strong acids, while others induce cell lethality and stress sensitivity, presumably as result of the simultaneous increases in dosages of multiple genes. We suggest that our PCDup technology will accelerate studies into the phenotypic changes resulting from alteration of gene dosage balance of multiple genes and will provide new insights into the adaptive molecular mechanisms in the genome in segmental aneuploidy-derived human diseases.
HPVbase – a knowledgebase of viral integrations, methylation patterns and microRNAs aberrant expression: As potential biomarkers for Human papillomaviruses mediated carcinomas
Authors: Kumar Gupta Amit , Kumar Manoj
Published: July 2015

Human papillomaviruses (HPVs) are extremely associated with different carcinomas. Despite consequential accomplishments, there is still need to establish more promising biomarkers to discriminate cancerous progressions. Therefore, we have developed HPVbase (http://crdd.osdd.net/servers/hpvbase/), a comprehensive resource for three major efficacious cancer biomarkers i.e. integration and breakpoint events, HPVs methylation patterns and HPV mediated aberrant expression of distinct host microRNAs (miRNAs). It includes clinically important 1257 integrants and integration sites from different HPV types i.e. 16, 18, 31, 33 and 45 associated with distinct histological conditions. An inclusive HPV integrant and breakpoints browser was designed to provide easy browsing and straightforward analysis. Our study also provides 719 major quantitative HPV DNA methylation observations distributed in 5 distinct HPV genotypes from higher to lower in numbers namely HPV 16 (495), HPV 18 (113), HPV45 (66), HPV 31 (34) and HPV 33 (11). Additionally, we have curated and compiled clinically significant aberrant expression profile of 341 miRNAs including their target genes in distinct carcinomas, which can be utilized for miRNA therapeutics. A user-friendly web interface has been developed for easy data retrieval and analysis. We foresee that HPVbase an integrated and multi-comparative platform would facilitate reliable cancer diagnostics and prognosis.
Biochemical nature of Russell Bodies
Authors: Francesca Mossuto Maria , Ami Diletta , Anelli Tiziana , Fagioli Claudio , Maria Doglia Silvia , Sitia Roberto
Published: July 2015

Professional secretory cells produce and release abundant proteins. Particularly in case of mutations and/or insufficient chaperoning, these can aggregate and become toxic within or amongst cells. Immunoglobulins (Ig) are no exception. In the extracellular space, certain Ig-L chains form fibrils causing systemic amyloidosis. On the other hand, Ig variants lacking the first constant domain condense in dilated cisternae of the early secretory compartment, called Russell Bodies (RB), frequently observed in plasma cell dyscrasias, autoimmune diseases and chronic infections. RB biogenesis can be recapitulated in lymphoid and non-lymphoid cells by expressing mutant Ig-μ, providing powerful models to investigate the pathophysiology of endoplasmic reticulum storage disorders. Here we analyze the aggregation propensity and the biochemical features of the intra- and extra-cellular Ig deposits in human cells, revealing β-aggregated features for RB.