bluuebunny/crossref_metadata_2025 huggingface dataset:
The Application of Vinamidinium Salt to the Synthesis of 3-Chloro-α-carbolines
Authors: Xu Guangyu , Tian Shaixiao , Mao Yu , Jiang Yongjun
Published: February 2018

A convenient synthesis of 3-chloro-α-carbolines by the condensation of vinamidinium salt with 2-indolinones via two steps is reported. This protocol has the advantages of readily available starting materials, high yields and easy workup.
Combined Frontotemporal Transbasal Approach for the Resection of a Giant Rathke's Cleft Cyst: Operative Video and Technical Nuances
Authors: Liu James
Published: February 2018

We present a case of a giant Rathke's cleft cyst with significant superior extension into the third and right lateral ventricles and lateral extension into the left Sylvian fissure and over the anterior clinoid process. An extended modification of the frontotemporal approach was performed using a combined frontotemporal transbasal approach. This allowed wide exposure to both transsylvian and subfrontal corridors to the retrochiasmatic space. This video atlas demonstrates the operative technique and surgical nuances of the skull base approach, microdissection of the tumor, and safe handling of the neurovascular structures. A gross total resection was achieved and the patient was neurologically intact with improved visual acuity. In summary, the combined frontotemporal transbasal approach is an important strategy in the armamentarium for the surgical management of giant Rathke's cleft cysts.

The link to the video can be found at: https://youtu.be/UjhnUZVi03I.
Die Beiträge des DDR-Sportmediziners und Nervenarztes Bernhard Schwarz (1918–1991) zum Boxen
Authors: Bart Katrin , Steinberg Holger
Published: February 2018

Diese vorliegende Studie beschäftigt sich erstmals mit dem DDR-Sportmediziner und Nervenarzt Bernhard Schwarz. Es werden die von Schwarz zwischen 1953 und 1966 vorgelegten Arbeiten über den Boxsport und dessen gesundheitliche Folgen, insbesondere das Schädel-Hirn-Trauma, vorgestellt, analysiert und in den Kontext der heute hoch aktuellen Diskussion gestellt. Dabei zeigt sich, dass Schwarz, Lehrstuhlinhaber und Direktor der Klinik für Psychiatrie an der Universität Leipzig sowie Arzt der DDR-Boxnationalmannschaft, früh aufgrund eigener systematischer klinischer Reihenuntersuchungen auf die gesundheitlichen Gefahren dieses Sports hinwies. Durch eine engmaschige und geschulte Begleitung des Sportlers sowohl durch den Trainer als auch durch den Arzt, sowie durch Änderungen der Wettkampfbedingungen meinte er die Gefahren für den Sportler deutlich minimieren zu können und trat somit gegen ein Verbot des Boxens ein. Insbesondere griff Schwarz Vorschläge zur Prävention auf und erweiterte sie durch eigene Forderungen. Diese stimmen bemerkenswert in Vielem mit den heute gültigen Regularien zur Risikominimierung überein. Zu diesen Vorschlägen gehörte beispielsweise, dass der Ringarzt eine qualifizierte Ausbildung erhalten müsse, um Zustände einer Gefährdung zu erkennen. Eine auch in diesem Sinne zu erwerbende Lizenz ist heute Voraussetzung für den Arzt, um die Sportler betreuen zu dürfen. Des Weiteren verfolgte Schwarz das Konzept einer ganzheitlichen Medizin. Er forderte, dass die Boxer vielseitig zu trainieren hätten und bei Verletzungen umfassend zu behandeln seien. Dabei spielte für den Nervenarzt die Psychotherapie eine große Rolle. Der Rehabilitation maß er eine Schlüsselfunktion bei, deren therapeutisches Ziel erst erreicht sei, wenn die soziale und berufliche Wiedereingliederung des Patienten gelinge.
Correction: Measuring impact in the humanities: learning from accountability and economics in a contemporary history of cultural value
Authors: Bulaitis Zoe
Published: February 2018

On page 7 of the PDF under the subheading “Alternative assessment criteria in valuations of the humanities” in the second paragraph there was a quotation incorrectly attributed to Matthew Arnold (1869) which has now been corrected to attribute Oliver Bennett (2005).
Individually grown cobalt nanowires as magnetic force microscopy probes
Authors: Alotaibi Shuaa , Samba Joshua , Pokharel Sabin , Lan Yucheng , Uradu Kelechi , Afolabi Ayodeji , Unlu Ilyas , Basnet Gobind , Aslan Kadir , Flanders Bret N. , Lisfi Abdellah , Ozturk Birol
Published: February 2018

AC electric fields were utilized in the growth of individual high-aspect ratio cobalt nanowires from simple salt solutions using the Directed Electrochemical Nanowire Assembly method. Nanowire diameters were tuned from the submicron scale to 40 nm by adjusting the AC voltage frequency and the growth solution concentration. The structural properties of the nanowires, including shape and crystallinity, were identified using electron microscopy. Hysteresis loops obtained along different directions of an individual nanowire using vibrating sample magnetometry showed that the magnetocrystalline anisotropy energy has the same order of magnitude as the shape anisotropy energy. Additionally, the saturation magnetization of an individual cobalt nanowire was estimated to be close to the bulk single crystal value. A small cobalt nanowire segment was grown from a conductive atomic force microscope cantilever tip that was utilized in magnetic force microscopy (MFM) imaging. The fabricated MFM tip provided moderate quality magnetic images of an iron-cobalt thin-film sample.
Total internal reflection effect on gyrotropic interface
Authors: Glushchenko Alexander G. , Glushchenko Eugene P. , Zhukov Sergey V.
Published: February 2018

This article considers the physical features of total internal reflection at gyrotropic and isotropic interfaces for two cases: electrical gyrotropy (plasma) and magnetic gyrotropy (ferrite). It is shown that the plasma magnetization may lead to the formation of the total internal reflection effect, which does not occur in isotropic plasma. The threshold values of the magnetic field, which are necessary for the total internal reflection effect, are determined. The total internal reflection effect on a ferrite-dielectric interface for waves emanating from different angles is observed in various frequency ranges and magnetization fields. The study points out the possibility of changing the total internal reflection angle value in large limits due to a change in the external magnetic field magnitude. The calculation results of the total internal reflection angle dependence on the external magnetic field magnitude are presented. The formulas are elaborated for calculating the total internal reflection angles of different interfaces for gyrotropic and isotropic media. The generalized formulas are defined for calculating the Doppler effect in the gyrotropic media. The study demonstrates how the velocity of the media interface affects the limiting angle of total internal refection.
Experimental investigation of mode transitions in asymmetric capacitively coupled radio-frequency Ne and CF4 plasmas
Authors: Liu Gang-Hu , Liu Yong-Xin , Bai Li-Shui , Zhao Kai , Wang You-Nian
Published: February 2018

The dependence of the electron density and the emission intensity on external parameters during the transitions of the electron power absorption mode is experimentally studied in asymmetric electropositive (neon) and electronegative (CF4) capacitively coupled radio-frequency plasmas. The spatio-temporal distribution of the emission intensity is measured with phase resolved optical emission spectroscopy and the electron density at the discharge center is measured by utilizing a floating hairpin probe. In neon discharge, the emission intensity increases almost linearly with the rf voltage at all driving frequencies covered here, while the variation of the electron density with the rf voltage behaves differently at different driving frequencies. In particular, the electron density increases linearly with the rf voltage at high driving frequencies, while at low driving frequencies the electron density increases slowly at the low-voltage side and, however, grows rapidly, when the rf voltage is higher than a certain value, indicating a transition from α to γ mode. The rf voltage, at which the mode transition occurs, increases with the decrease of the driving frequency/the working pressure. By contrast, in CF4 discharge, three different electron power absorption modes can be observed and the electron density and emission intensity do not exhibit a simple dependence on the rf voltage. In particular, the electron density exhibits a minimum at a certain rf voltage when the electron power absorption mode is switching from drift-ambipolar to the α/γ mode. A minimum can also be found in the emission intensity at a higher rf voltage when a discharge is switching into the γ mode.
Detection of small-size solder ball defects through heat conduction analysis
Authors: Zhou Xiuyun , Chen Yaqiu , Lu Xiaochuan
Published: February 2018

Aiming to solve the defect detection problem of a small-size solder ball in the high density chip, heat conduction analysis based on eddy current pulsed thermography is put forward to differentiate various defects. With establishing the 3D finite element model about induction heating, defects such as cracks and void can be distinguished by temperature difference resulting from heat conduction. Furthermore, the experiment of 0.4 mm-diameter solder balls with different defects is carried out to prove that crack and void solder can be distinguished. Three kinds of crack length on a gull-wing pin are selected, including 0.24 mm, 1.2 mm, and 2.16 mm, to verify that the small defect can be discriminated. Both the simulation study and experiment result show that the heat conduction analysis method is reliable and convenient.
Stabilization of burst laser pulse storage in an optical enhancement cavity using a counter propagating mode
Authors: Sakaue Kazuyuki , Washio Masakazu , Araki Sakae , Fukuda Masafumi , Honda Yosuke , Terunuma Nobuhiro , Urakawa Junji
Published: February 2018

We describe the stabilization technique of an optical enhancement cavity using a counter propagating mode. The burst amplification of the injection laser in the main path induces a drastic change in the laser intensity and disturbs the stabilization of the enhancement cavity. We have used a counter propagating mode to achieve a 4% intensity jitter and 0.6 mJ pulse storage inside the cavity at the maximum of the burst region. Our results indicate that the counter propagating mode has the same resonant condition as the main mode and thus becomes useful for stabilizing the enhancement cavity. We also determined that the burst amplification brought about no decrease in the enhancement factor in the cavity due to the degradation of laser quality.
A generalization of the injectivity condition for projected entangled pair states
Authors: Molnar Andras , Ge Yimin , Schuch Norbert , Cirac J. Ignacio
Published: February 2018

We introduce a family of tensor network states that we term semi-injective Projected Entangled-Pair States (PEPSs). They extend the class of injective PEPSs and include other states, like the ground states of the AKLT and the CZX models in square lattices. We construct parent Hamiltonians for which semi-injective PEPSs are unique ground states. We also determine the necessary and sufficient conditions for two tensors to generate the same family of such states in two spatial dimensions. Using this result, we show that the third cohomology labeling of symmetry protected topological phases extends to semi-injective PEPSs.
Vibrational energy transfer and dissociation in O2–N2 collisions at hyperthermal temperatures
Authors: Andrienko Daniil A. , Boyd Iain D.
Published: February 2018

Simulation of vibrational energy transfer and dissociation in O2–N2 collisions is conducted using the quasi-classical trajectory method on an ab initio potential energy surface. Vibrationally resolved rate coefficients are obtained in a high-temperature region between 8000 and 20 000 K by means of the cost-efficient classical trajectory propagation method. A system of master equations is constructed using the new dataset in order to simulate thermal and chemical nonequilibrium observed in shock flows. The O2 relaxation time derived from a solution of the master equations is in good agreement with the Millikan and White correlation at lower temperatures with an increasing discrepancy toward the translational temperature of 20 000 K. At the same time, the N2 master equation relaxation time is similar to that derived under the assumption of a two-state system. The effect of vibrational-vibrational energy transfer appears to be crucial for N2 relaxation and dissociation. Thermal equilibrium and quasi-steady state dissociation rate coefficients in O2–N2 heat bath are reported.
Alloying effects on superionic conductivity in lithium indium halides for all-solid-state batteries
Authors: Zevgolis Alysia , Wood Brandon C. , Mehmedović Zerina , Hall Alex T. , Alves Thomaz C. , Adelstein Nicole
Published: February 2018

Alloying of anions is a promising engineering strategy for tuning ionic conductivity in halide-based inorganic solid electrolytes. We explain the alloying effects in Li3InBr6−xClx, in terms of strain, chemistry, and microstructure, using first-principles molecular dynamics simulations and electronic structure analysis. We find that strain and bond chemistry can be tuned through alloying and affect the activation energy and maximum diffusivity coefficient. The similar conductivities of the x = 3 and x = 6 compositions can be understood by assuming that the alloy separates into Br-rich and Cl-rich regions. Phase-separation increases diffusivity at the interface and in the expanded Cl-region, suggesting microstructure effects are critical. Similarities with other halide superionic conductors are highlighted.
The influence of dynamical change of optical properties on the thermomechanical response and damage threshold of noble metals under femtosecond laser irradiation
Authors: Tsibidis George D.
Published: February 2018

We present a theoretical investigation of the dynamics of the dielectric constant of noble metals following heating with ultrashort pulsed laser beams and the influence of the temporal variation of the associated optical properties on the thermomechanical response of the material. The effect of the electron relaxation time on the optical properties based on the use of a critical point model is thoroughly explored for various pulse duration values (i.e., from 110 fs to 8 ps). The proposed theoretical framework correlates the dynamical change in optical parameters, relaxation processes and induced strains-stresses. Simulations are presented by choosing gold as a test material, and we demonstrate that the consideration of the aforementioned factors leads to significant thermal effect changes compared to results when static parameters are assumed. The proposed model predicts a substantially smaller damage threshold and a large increase of the stress which firstly underlines the significant role of the temporal variation of the optical properties and secondly enhances its importance with respect to the precise determination of laser specifications in material micromachining techniques.
Tunable photoelectric response in NiO-based heterostructures by various orientations
Authors: Luo Yidong , Qiao Lina , Zhang Qinghua , Xu Haomin , Shen Yang , Lin Yuanhua , Nan Cewen
Published: February 2018

We engineered various orientations of NiO layers for NiO-based heterostructures (NiO/Au/STO) to investigate their effects on the generation of hot electrons and holes. Our calculation and experimental results suggested that bandgap engineering and the orientation of the hole transport layer (NiO) were crucial elements for the optimization of photoelectric responses. The (100)-orientated NiO/Au/STO achieved the highest photo-current density (∼30 μA/cm2) compared with (111) and (110)-orientated NiO films, which was attributed to the (100) films's lowest effective mass of photogenerated holes (∼1.82 m0) and the highest efficiency of separating and transferring electron-holes of the (100)-orientated sample. Our results opened a direction to design a high efficiency photoelectric solar cell.
In situ electrostatic characterisation of ion beams in the region of ion acceleration
Authors: Bennet Alexander , Charles Christine , Boswell Rod
Published: February 2018

In situ and ex situ techniques have been used to measure directional ion beams created by a sharp axial potential drop in low pressure expanding plasmas. Although Retarding Field Energy Analysers (RFEAs) are the most convenient technique to measure the ion velocities and plasma potentials along with the plasma density, they are bulky and are contained in a grounded shield that may perturb the electric potential profile of the expanding plasma. In principle, ex situ techniques produce a more reliable measurement and Laser Induced Fluorescence spectroscopy (LIF) has previously been used to characterise the spatial velocity profile of ion beams in the same region of acceleration for a range of pressures. Here, satisfactory agreement between the ion velocity profiles measured by LIF and RFEA techniques has allowed the RFEA method to be confidently used to probe the ion beam characteristics in the regions of high gradients in plasma density and DC electric fields which have previously proven difficult.
Propagation of modulated electron and X-ray beams through matter and interactions with radio-frequency structures
Authors: Harris J. R. , Miller R. B.
Published: February 2018

The generation and evolution of modulated particle beams and their interactions with resonant radiofrequency (RF) structures are of fundamental interest for both particle accelerator and vacuum electronic systems. When the constraint of propagation in a vacuum is removed, the evolution of such beams can be greatly affected by interactions with matter including scattering, absorption, generation of atmospheric plasma, and the production of multiple generations of secondary particles. Here, we study the propagation of 21 MeV and 25 MeV electron beams produced in S-band and L-band linear accelerators, and their interaction with resonant RF structures, under a number of combinations of geometry, including transmission through both air and metal. Both resonant and nonresonant interactions were observed, with the resonant interactions indicating that the RF modulation on the electron beam is at least partially preserved as the beam propagates through air and metal. When significant thicknesses of metal are placed upstream of a resonant structure, preventing any primary beam electrons from reaching the structure, RF signals could still be induced in the structures. This indicated that the RF modulation present on the electron beam was also impressed onto the x-rays generated when the primary electrons were stopped in the metal, and that this RF modulation was also present on the secondary electrons generated when the x-rays struck the resonant structures. The nature of these interactions and their sensitivities to changes in system configurations will be discussed.
Note: Reflection zone plates as highly resolving broadband optics for soft X-ray laboratory spectrometers
Authors: Jonas A. , Meurer T. , Kanngießer B. , Mantouvalou I.
Published: February 2018

The resolving power and relative efficiency of two off-axis reflection zone plates (RZPs) in the soft X-ray range between 1 nm and 5 nm were investigated. RZPs focus only a very narrow bandwidth around the design wavelength. By misaligning the RZP, the focused wavelength can be tuned through a much wider spectral range. Using a laser-produced plasma source, we demonstrate that a single RZP can be efficiently used for spectroscopy at arbitrary wavelengths in the investigated soft X-ray range.
Temperature-dependent conformations of exciton-coupled Cy3 dimers in double-stranded DNA
Authors: Kringle Loni , Sawaya Nicolas P. D. , Widom Julia , Adams Carson , Raymer Michael G. , Aspuru-Guzik Alán , Marcus Andrew H.
Published: February 2018

Understanding the properties of electronically interacting molecular chromophores, which involve internally coupled electronic-vibrational motions, is important to the spectroscopy of many biologically relevant systems. Here we apply linear absorption, circular dichroism, and two-dimensional fluorescence spectroscopy to study the polarized collective excitations of excitonically coupled cyanine dimers (Cy3)2 that are rigidly positioned within the opposing sugar-phosphate backbones of the double-stranded region of a double-stranded (ds)–single-stranded (ss) DNA fork construct. We show that the exciton-coupling strength of the (Cy3)2-DNA construct can be systematically varied with temperature below the ds–ss DNA denaturation transition. We interpret spectroscopic measurements in terms of the Holstein vibronic dimer model, from which we obtain information about the local conformation of the (Cy3)2 dimer, as well as the degree of static disorder experienced by the Cy3 monomer and the (Cy3)2 dimer probe locally within their respective DNA duplex environments. The properties of the (Cy3)2-DNA construct we determine suggest that it may be employed as a useful model system to test fundamental concepts of protein-DNA interactions and the role of electronic-vibrational coherence in electronic energy migration within exciton-coupled bio-molecular arrays.
Field induced decrystallization of silicon: Evidence of a microwave non-thermal effect
Authors: Nozariasbmarz Amin , Dsouza Kelvin , Vashaee Daryoosh
Published: February 2018

It is rather strange and not fully understood that some materials decrystallize when exposed to microwave radiation, and it is still debatable if such a transformation is a thermal or non-thermal effect. We hereby report experimental evidences that weight the latter effect. First, a single crystal silicon wafer exposed to microwaves showed strong decrystallization at high temperature. Second, when some areas of the wafer were masked with metal coating, only the exposed areas underwent decrystallization. Transmission electron microscopy analysis, x-ray diffraction data, and thermal conductivity measurements all indicated strong decrystallization, which occurred in the bulk of the material and was not a surface effect. These observations favor the existence of a non-thermal microwave effect.
Moore's curve structuring of ferromagnetic composite PE-NiFe absorbers
Authors: Fernez N. , Arbaoui Y. , Maalouf A. , Chevalier A. , Agaciak P. , Burgnies L. , Queffelec P. , Laur V. , Lheurette É.
Published: February 2018

A ferromagnetic material involving nickel-iron particles embedded in a polyethylene matrix is synthesized and electrically characterized between 1 and 12 GHz. These measurements show the combination of electric and magnetic activity along with significant loss terms. We take benefit of these properties for the design of broadband electromagnetic absorbers. To this aim, we use a fractal structuring based on Moore curves. The advantage of etching patterns over metallic ones is clearly evidenced, and several pattern absorbers identified by their Moore's order iteration are designed and analyzed under oblique incidence.
Effect of electron-beam deposition process variables on the film characteristics of the CrOx films
Authors: Chiu Po-kai , Liao Yi-Ting , Tsai Hung-Yin , Chiang Donyau
Published: February 2018

The film characteristics and optical properties of the chromium oxide films on the glass substrates prepared by electron-beam deposition with different process variables were investigated. The process variables included are the various oxygen flow rates, the different applied substrate temperatures, and the preparation process in Ar or O2 surrounding environment with and without ion-assisted deposition. The optical constants of the deposited films are determined from the reflectance and transmittance measurements obtained using a spectrophotometer with wavelengths ranging from 350 nm to 2000 nm. The microstructures of the films were examined by the XRD, SEM, and XPS. The electrical conductivity was measured by a four-point probe instrument. The resulting microstructures of all the prepared films are amorphous and the features of the films are dense, uniform and no pillar structure is observed. The refractive index of deposited films decrease with oxygen flow rate increase within studied wavelengths and the extinction coefficients have the same trend in wavelengths of UV/Vis ranges. Increasing substrate temperature to 200 oC results in increase of both refractive index and extinction coefficient, but substrate temperatures below 150 oC show negligible effect on optical constants. The optical and electrical properties in the prepared CrOx films are illustrated by the analyzed XPS results, which decompose the enveloped curve of chromium electron energy status into the constituents of metal Cr, oxides CrO2 and Cr2O3. The relative occupied area contributed from metal Cr and area contributed from the other oxides can express the concentration ratio of free electron to covalent bonds in deposited films and the ratio is applied to explain the film characteristics, including the optical constants and sheet resistance.
Coordination-Initiated Nitroxide-Mediated Polymerization (CI-NMP)
Authors: Audran Gérard , Bagryanskaya Elena , Edeleva Mariya , Marque Sylvain R. A. , Parkhomenko Dmitriy , Tretyakov Evgeny , Zhivetyeva Svetlana
Published: February 2018

Preparation of materials by nitroxide-mediated polymerization (NMP) is well known nowadays. To increase the possible usefulness of NMP for the production of hybrid materials or polymer-decorated complexes, coordination-initiated NMP (CI-NMP) was developed and investigated here. CI-NMP was exemplified using the instantaneous and spontaneous reaction of alkoxyamines carrying a pyridyl moiety on the alkyl group and the Zn(hfac)2 (hfac: hexafluoroacetylacetonate) complex as a metal centre. NMP of styrene and n-butyl acrylate was carried out with either previously or in situ-prepared complexes. Both approaches afforded NMP of the same quality. The positive influence of metal centre coordination is highlighted by efficient NMP at 90°C.
Hyperspectral database prediction of ecological characteristics for grass species of alpine grasslands
Authors: Yu Huan , Kong Bo , Wang Guangxing , Sun Hua , Wang Lu
Published: February 2018

Alpine grasslands are being degraded because of human activities and associated global climate change. Mapping the spatial distributions and ecological characteristics of grass species is essential for scientific management of grasslands. However, traditional field-survey methods are costly or even impossible owing to poor accessibility. Hyperspectral remote sensing provides solutions for the purpose. This study was conducted in Shenzha County of the Qiangtang Plateau, north-western Qinghai–Tibet Plateau, to examine the potential of using hyperspectral data for identifying the grass species and predicting their ecological characteristics in the alpine grasslands dominated by Stipa purpurea with co-existing species Leontopodium nanum and Oxytropis microphylla. Hyperspectral data were collected in 106 sample quadrats and the ecological characteristics of each quadrat (number and height of plants, vegetation cover, etc.) were measured. The results of spectral data analysis and regression modelling showed the following. (i) The near- and middle-infrared region was more appropriate than the visible region for discriminating the grass species. (ii) The enhanced spectral variables had much higher correlations with the ecological characteristics than the original bands. (iii) Most of the 23 derived enhanced spectral variables were significantly correlated with the number and height of the dominant species plants within the quadrats. (iv) The vegetation cover could be accurately predicted by using the models based on the enhanced spectral variables of the field-collected hyperspectral data with the relative RMSE values <28%. (v) The ecological characteristics of the dominant species could be more accurately estimated than of co-existing species. Overall, this study suggests that the hyperspectral database method provided great potential to predict the ecological characteristics of grass species in alpine grasslands.
Green-tree retention and recovery of an old-forest specialist, the southern red-backed vole (Myodes gapperi), 20 years after harvest
Authors: Sullivan Thomas P. , Sullivan Druscilla S.
Published: February 2018

Context Populations of many mammalian species are reduced as a result of clearcutting, despite the concurrent objectives of wood production and conservation of mammal diversity on cutover forest land. To help ameliorate this decline, green-tree retention (GTR) leaves large live trees after harvest to provide mature forest habitat and increase structural diversity of the regenerating stand. Aims To test the hypotheses (H) that, at 20 years after harvest, (H1) abundance, reproduction and survival of the southern red-backed vole (Myodes gapperi), as well as (H2) abundance and species diversity of the forest-floor small mammal community, would increase with the basal area (BA) and density of residual trees after harvest. Methods Small mammals were live-trapped in 2015–16 in replicated clearcut, dispersed retention, aggregated retention, patch cut and uncut forest sites in mixed forests of Douglas fir (Pseudotsuga menziesii var. glauca) and lodgepole pine (Pinus contorta Dougl. var. latifolia) in southern British Columbia, Canada. Key results Mean BA and density of overstory coniferous trees were significantly different at 20 years post-harvest, being higher on patch cut and uncut forest sites than on the clearcut and GTR sites. M. gapperi populations were significantly greater in aggregated retention and uncut forest sites than in the other sites, but demographic parameters were similar among sites, and therefore H1 was partly supported. Mean total abundance of small mammals differed significantly among sites, with the highest overall numbers occurring in the aggregated retention (16.2), clearcut (13.6) and uncut forest sites (11.9). Mean species richness and diversity were highest in the GTR and clearcut sites. Thus, H2 was not supported. Conclusions Recovery of M. gapperi in aggregated retention sites with 10m2 ha–1 BA of residual trees, as a group, occurred at 20 years post-harvest. Implications Aggregated retention of residual trees should help provide some habitat to conserve forest mammals on harvest openings, but successional development up to 20 years post-harvest may be required.
Distribution and relative abundance of forest duikers in Dassioko Sud Forest Reserve (coastal Côte d'Ivoire)
Authors: Yao K. A. , Bitty E. A. , Kassé K. B. , Kouakou Y. C. , Yaokokoré-Beibro K. H. , Bi S. Gonedelé , McGraw W. Scott
Published: February 2018

Context
Duikers play a vital role in maintaining forest ecosystems, as both seed dispersers and prey. In West Africa, duikers are also an important source of food and income; however, it is likely that some species are now being hunted at unsustainable levels. So as to contribute to duiker conservation, we used line-transect data and additional information on dung and track counts to estimate relative abundance and establish distribution patterns of forest duikers in Côte d’Ivoire’s Dassioko Sud Forest Reserve (DSFR), a poorly known, remnant coastal rainforest. We also collected basic information on hunting pressure.

Methods
Forest duiker counts were made twice per month from July 2013 to March 2014 on six line transects of varying lengths (5.6–6.7km) and in different regions of the DSFR, representing different habitat types. The number of sightings per kilometre walked, defined as ‘encounter rate’, was used to compute an index of relative abundance. We recorded all evidence of poachers and used these data to generate a poaching index (# poaching signs per kilometre) for different habitat types.

Key results
The DSFR has lost three of seven total forest duiker species and populations of the four remaining species are declining. Encounter rates were greatest for Philantomba maxwellii (0.46 indices km–1) and accounted for 68% of total encounters. Cephalophus niger, C. dorsalis and C. silvicultor were encountered at similar (0.07 indices km–1) but much lower rates. For all species, mean encounter rates were highest in degraded forest (0.38–0.73 indices km–1), followed by secondary (0.2–0.44 indices km–1) and primary (0.19–0.44 indices km–1) forest.

Conclusions
Of the four forest duiker species still present in the DSFR, the black, bay and yellow-backed duikers are the most affected by anthropogenic pressures. Duiker abundance in the DSFR varies with habitat type. This variation is apparently influenced by differences in forest structure, poaching pressure and proximity to villages.

Implications
The study provides baseline data for future managing of ungulate populations in the DSFR. We recommend that a biomonitoring study of duiker populations be initiated immediately to help determine population trends, investigate habitat preferences, and help curb illegal hunting activities in this important forest reserve.
Brain-to-brain coupling during handholding is associated with pain reduction
Authors: Goldstein Pavel , Weissman-Fogel Irit , Dumas Guillaume , Shamay-Tsoory Simone G.
Published: February 2018

Significance

The mechanisms that underlie social touch analgesia are largely unknown. Here, we apply a hyperscanning approach with real-life interaction of dyads to examine the association between brain-to-brain coupling and pain relief. Our findings indicate that hand-holding during pain increases the brain-to-brain coupling network that correlates with the magnitude of the analgesia and the observer’s empathic accuracy. These findings make a unique contribution to our understanding of physiological mechanisms of touch-related analgesia.
Interferometric mapping of material properties using thermal perturbation
Authors: Goetz Georges , Ling Tong , Gupta Tushar , Kang Seungbum , Wang Jenny , Gregory Patrick D. , Park B. Hyle , Palanker Daniel
Published: February 2018

Significance

Rapid, accurate, and nondestructive mapping of material properties is of great interest in many fields, with applications ranging from detection of defects or other subsurface features in semiconductors to estimating temperature rise in various tissue layers during laser therapy. We demonstrate the speed and precision of two interferometric techniques, quantitative phase imaging and phase-resolved optical coherence tomography, in recording optical phase changes induced by energy deposition in various materials. Such phase perturbations can be used to infer sample properties, ranging from absorption and temperature maps to distribution of electric field or resistivity. We derive the theoretical sensitivity limits of such techniques and demonstrate their applicability to the mapping of absorption coefficients, temperature, and electric fields in synthetic and biological samples.
Social norm enforcement in ethnically diverse communities
Authors: Winter Fabian , Zhang Nan
Published: February 2018

Significance

How does ethnic diversity influence the maintenance of social norms in complex, Western societies? We provide evidence from a natural field experiment examining reactions to norm violations in multiethnic German neighborhoods. We uncover asymmetric patterns of norm enforcement in interethnic encounters: “Native” Germans are more active in sanctioning norm violations, while ethnic minorities are more likely to be targeted for sanctions. We link these dynamics to prevailing status inequalities between minorities and natives in German society. We further show that, as a consequence of such asymmetries, social control tends to rise with ethnic diversity.
Direct observation of backbone planarization via side-chain alignment in single bulky-substituted polythiophenes
Authors: Raithel Dominic , Simine Lena , Pickel Sebastian , Schötz Konstantin , Panzer Fabian , Baderschneider Sebastian , Schiefer Daniel , Lohwasser Ruth , Köhler Jürgen , Thelakkat Mukundan , Sommer Michael , Köhler Anna , Rossky Peter J. , Hildner Richard
Published: February 2018

Significance

Conjugated polymers are promising materials for flexible electronics and photovoltaics. Recent progress in polymer design led to a rise in device efficiency. Tailoring intramolecular interactions is a central design element, which allows fine-tuning of optical and electronic properties. However, prediction and measurement of intrinsic properties of newly synthesized polymers is challenging, as they are often hidden by ensemble effects. Single-molecule spectroscopy allows revelation of the intrinsic changes upon chemical modification, here specifically a variation of the side chains. Surprisingly, a more disordered, bulky side chain leads to a higher order and better conjugation within the electronically active backbone of a single chain. This study gives detailed insights into changes in photophysical properties and suggests new ideas for synthesis.
Reforestation can sequester two petagrams of carbon in US topsoils in a century
Authors: Nave Lucas E. , Domke Grant M. , Hofmeister Kathryn L. , Mishra Umakant , Perry Charles H. , Walters Brian F. , Swanston Christopher W.
Published: February 2018

Significance

Forestland in the United States is a carbon (C) sink, offsetting ∼10% of annual greenhouse gas emissions and mitigating climate change. Most of the C in forests is held in soils, and the capacity of forest soils to sequester C makes them a major component of the US forest C sink. Where reforestation is presently occurring, either through deliberate replanting after forestland is disturbed (e.g., burned), or where previously nonforested lands (e.g., cultivated) are converting to forestland, topsoils are accumulating C. However, these C accumulation rates are poorly constrained; quantifying them with empirical data are critical to accurately represent the role of reforestation in the US C budget and forecast the longevity of the US forest C sink.
Inorganic phosphate, arsenate, and vanadate enhance exonuclease transcript cleavage by RNA polymerase by 2000-fold
Authors: Gottesman Max E. , Mustaev Arkady
Published: February 2018

Significance

To understand how RNA polymerase (RNAP) can synthesize or degrade RNA, and how these processes are regulated, it is necessary to elucidate the catalytic mechanisms of these reactions. Catalysis is sensitive to external factors that modulate the rate of polymerization or hydrolytic attack on the RNA. Here we report that a ubiquitous cellular metabolite, inorganic phosphate, stimulates RNAP exonuclease transcript cleavage activity nearly 2,000-fold. This finding represents a stunning example of how simple cellular molecules can reprogram an enzyme’s active center by providing functional groups and suggests an additional important role for inorganic phosphate in cell biology.
A comprehensive genomic history of extinct and living elephants
Authors: Palkopoulou Eleftheria , Lipson Mark , Mallick Swapan , Nielsen Svend , Rohland Nadin , Baleka Sina , Karpinski Emil , Ivancevic Atma M. , To Thu-Hien , Kortschak R. Daniel , Raison Joy M. , Qu Zhipeng , Chin Tat-Jun , Alt Kurt W. , Claesson Stefan , Dalén Love , MacPhee Ross D. E. , Meller Harald , Roca Alfred L. , Ryder Oliver A. , Heiman David , Young Sarah , Breen Matthew , Williams Christina , Aken Bronwen L. , Ruffier Magali , Karlsson Elinor , Johnson Jeremy , Di Palma Federica , Alfoldi Jessica , Adelson David L. , Mailund Thomas , Munch Kasper , Lindblad-Toh Kerstin , Hofreiter Michael , Poinar Hendrik , Reich David
Published: February 2018

Significance

Elephantids were once among the most widespread megafaunal families. However, only three species of this family exist today. To reconstruct their evolutionary history, we generated 14 genomes from living and extinct elephantids and from the American mastodon. While previous studies examined only simple bifurcating relationships, we found that gene flow between elephantid species was common in the past. Straight-tusked elephants descend from a mixture of three ancestral populations related to the ancestor of African elephants, woolly mammoths, and present-day forest elephants. We detected interbreeding between North American woolly and Columbian mammoths but found no evidence of recent gene flow between forest and savanna elephants, demonstrating that both gene flow and isolation have been central in the evolution of elephantids.
Natural diamond formation by self-redox of ferromagnesian carbonate
Authors: Chen Ming , Shu Jinfu , Xie Xiande , Tan Dayong , Mao Ho-kwang
Published: February 2018

Significance

The presence of extra reducer was thought to be essential for producing natural diamonds from reduction of carbonates. The present study of the Xiuyan meteoritic crater, however, finds natural diamond formation via a subsolidus self-redox of a ferromagnesian carbonate during shock compression to 25–45 GPa and 800–900 °C without melting, fluid, and another reductant. The ability of carbonate to produce diamond by itself implies that diamond would be a very common mineral in the lower mantle where the carbonates are abundant and pressures and temperatures are sufficiently high.
Effects of maturation on the conformational free-energy landscape of SOD1
Authors: Culik Robert M. , Sekhar Ashok , Nagesh Jayashree , Deol Harmeen , Rumfeldt Jessica A. O. , Meiering Elizabeth M. , Kay Lewis E.
Published: February 2018

Significance

Copper, zinc superoxide dismutase 1 (SOD1) is an enzyme involved in free radical scavenging in the cell. Despite the high stability of the mature protein, mutations, covalent modifications, and increased populations of immature forms result in instability and misfolding of SOD1 that is neurotoxic. Here, we study how the structure and dynamics of SOD1 change as a function of maturation. We find that as SOD1 progresses to its final active conformation, the free-energy landscapes for each successive state along the maturation pathway appear to become smoother with less exploration of higher energy conformations. Our results suggest that maturation may occur via a series of steps in which the transiently populated structures of preceding states successively become the dominant conformations.
Host biotin is required for liver stage development in malaria parasites
Authors: Dellibovi-Ragheb Teegan A. , Jhun Hugo , Goodman Christopher D. , Walters Maroya S. , Ragheb Daniel R. T. , Matthews Krista A. , Rajaram Krithika , Mishra Satish , McFadden Geoffrey I. , Sinnis Photini , Prigge Sean T.
Published: February 2018

Significance

Malaria parasites require certain host nutrients for growth and survival. In this project, we examined the role of the human vitamin biotin in all stages of the malaria life cycle. We cultured blood- and liver-stage malaria parasites in the absence of biotin and found that, whereas blood-stage replication was unaffected, liver-stage parasites deprived of biotin were no longer capable of establishing a blood-stage infection. Interestingly, biotin depletion resulted in more severe developmental defects than the genetic disruption of parasite biotin metabolism. This finding suggests that host biotin metabolism also contributes to parasite development. Because neither the parasite nor the human host can synthesize biotin, parasite infectivity may be affected by the nutritional status of the host.
Re/constructing politics through social & online media
Authors: Krzyżanowski Michał , Tucker Joshua A.
Published: February 2018

In recent years, the connection between online and in particular social media and politics has become one of the central ones in contemporary societies, and has been explored very widely in political research and media and communication studies. Against such growing body of research, this Special Issue foregrounds the role of language as a key carrier of political ideologies and practices on social and online media. It aims to advance the scholarly understanding of contemporary political and democratic dynamics by postulating the need for a broader, problem-driven look at how political practices and ideologies are articulated on social and online media. It illustrates the value of a cross-disciplinary take that allows overcoming both the classic (e.g. qualitative vs. quantitative) and the more recent (e.g. small vs. big data) divides in explorations of the language of online and politics.
Examining the role of cross-generational attrition in the development of Spanish as a heritage language
Authors: Pascual y Cabo Diego
Published: February 2018

The goal of this article is to contribute to the literature on heritage speaker bilingualism by weighing in on the current debate regarding the source(s) of heritage speaker linguistic differences. Focusing on Spanish dative experiencers -gustar-like verbs-, I report on production and comprehension data from heritage speaker children and adults, from monolingual children and adults, as well as from adult bilingual immigrants. The results show (i) comprehension differences from expected outcomes for all heritage groups but not for the adult monolingual and bilingual control groups, and (ii) significant variation in the adult bilingual immigrant group’s production of the dative marker ‘a’ in obligatory contexts. I posit that this variation is at least in part responsible for the heritage speaker outcomes observed.
Relative clauses in Persian
Authors: Abdollahnejad Elias , Marefat Hamideh
Published: February 2018

This study is a corpus-based investigation of Persian relative clauses (RCs) used in written mode. 535 instances of RCs occurring in 1634 sentences in 40 editorials of four newspapers published in Iran were spotted and analyzed to determine the frequency of each RC type and the occurrence of certain features including complementizer ke, object marker râ, different representations of the relativised element in the modifying clause, and the status of gap and resumptive pronoun in the RC. The results indicated that subject RCs are the most frequent types. The tendency to use object marker râ before the modifying RC (Karimi, 2001) was confirmed. Besides, some tokens were witnessed contrasting Taghvaipour’s (2005) proposals on the ungrammaticality of resumption in Persian subject ordinary and object free RCs and the necessity of prefix hær- ‘ever’ in all Persian free RCs.
Are superordinates such asfurnitureandbelongingscollective nouns?
Authors: Gardelle Laure
Published: February 2018

One area of debate as to the boundaries of the class of “collective nouns” concerns non-count singular nouns such asfurniture, which are typically used for several units of different kinds. Arguments for and against inclusion have been put forward, but ultimately, what has been noted is a number of similarities and differences compared with count collective nouns. This makes both positions as legitimate, especially as collective nouns are a partly heterogeneous class (e.g. only those denoting humans, or sometimes animals, license plural override:the committee were…vs.*the bouquet were…). The present paper addresses the issue from a different angle, comparingfurniturenouns not just with other singular nouns (whether collective or superordinate), but with count nouns in the plural (e.g.toys). This new angle enables us to propose thatfurniturenouns are superordinate hyperonyms ofplural, rather than singular, categories. This notion accounts for all the similarities and differences noted betweenfurniturenouns and count collective nouns, and leads to the conclusion thatfurniturenouns are clearly not collective nouns. The analysis is then extended to non-count plural nouns that denote units (e.g.belongings), which have been neglected, or sometimes rejected on arbitrary grounds. The present study shows that they are not collective nouns either, and that they, too, are superordinates, some of them hyperonyms of plural categories.