bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast positive breakdown in lightning
Authors: Stock M. G. , Krehbiel P. R. , Lapierre J. , Wu T. , Stanley M. A. , Edens H. E.
Published: June 2017

VHF radiation sources produced by positive breakdown during lightning discharges are generally considered to be both weak and slowly propagating. However, as VHF lightning mapping systems have become more sensitive, even this weak radiation can be mapped. In addition to being a faint process, positive breakdown often produces bursts of energetic activity. During the bursts, the VHF emission is extremely bright, and the breakdown propagates at much higher speeds. Here we present VHF interferometric and time‐of‐arrival measurements of such fast positive breakdown events produced during three example flashes. Electric field change measurements show that the fast breakdown process carries positive charge. The extent and velocity of the breakdown is estimated by converting the angular source locations provided by the interferometer into Cartesian coordinates using three‐dimensional lightning mapping observations of the flash as a guide. Fast positive breakdown events are found to extend 100–2400 m into virgin air beyond the tip of the preceding positive leader, at speeds of 0.9–9 ×107 m s−1. The observations expand upon earlier observations of such breakdown and are similar to recently reported results that fast positive breakdown is the cause of high‐power narrow bipolar events.
Eclogite inclusions from subducted metaigneous continental crust (Malpica‐Tui Allochthonous Complex, NW Spain): Petrofabric, geochronology, and calculated seismic properties
Authors: Puelles P. , Beranoaguirre A. , Ábalos B. , Gil Ibarguchi J. I. , García de Madinabeitia S. , Rodríguez J. , Fernández‐Armas S.
Published: June 2017

This study describes the strain geometry, crystal‐plastic deformational features, isotopic age of metamorphism, and calculated seismic properties of two medium‐temperature eclogite types from the Malpica‐Tui Allochthonous Complex of Variscan NW Iberia. The eclogite types are eclogites with coronitic garnets and eclogites with a planolinear fabric. Both of them were buried, deformed and recrystallized under maximum pressure and temperature of 2.6 GPa and 610–640°C, and subsequently exhumed in a late Devonian subduction channel. The metamorphic peak of the subduction‐exhumation cycle occurred ~375 Ma ago. Omphacite petrofabric ties eclogites with coronitic garnet to noncoaxial constrictional strain and eclogites with planolinear fabrics to noncoaxial flattening strain and stretching along the lineation. We also used omphacite crystallographic preferred orientations to calculate and constrain the seismic properties of the eclogites. The slight variations in petrophysical properties observed are interpreted to result from variations in the strain regime recorded by pristine eclogites, or from variations in the modal proportions of the constituent high‐pressure minerals. We foresee that eclogite in subduction metamorphic complexes might be either seismically undetectable or detected as planar features with high impedance contrasts relative to their host rocks.
ULF geomagnetic activity effects on tropospheric temperature, specific humidity, and cloud cover in Antarctica, during 2003–2010
Authors: Regi Mauro , Redaelli Gianluca , Francia Patrizia , De Lauretis Marcello
Published: June 2017

In the present study we investigated the possible relationship between the ULF geomagnetic activity and the variations of several atmospheric parameters. In particular, we compared the ULF activity in the Pc1‐2 frequency band (100 mHz–5 Hz), computed from geomagnetic field measurements at Terra Nova Bay in Antarctica, with the tropospheric temperature T, specific humidity Q, and cloud cover (high cloud cover, medium cloud cover, and low cloud cover) obtained from reanalysis data set. The statistical analysis was conducted during the years 2003–2010, using correlation and Superposed Epoch Analysis approaches. The results show that the atmospheric parameters significantly change following the increase of geomagnetic activity within 2 days. These changes are evident in particular when the interplanetary magnetic field Bz component is oriented southward (Bz<0) and the By component duskward (By>0). We suggest that both the precipitation of electrons induced by Pc1‐2 activity and the intensification of the polar cap potential difference, modulating the microphysical processes in the clouds, can affect the atmosphere conditions.
Modeling the isotopic evolution of snowpack and snowmelt: Testing a spatially distributed parsimonious approach
Authors: Ala‐aho Pertti , Tetzlaff Doerthe , McNamara James P. , Laudon Hjalmar , Kormos Patrick , Soulsby Chris
Published: June 2017

Use of stable water isotopes has become increasingly popular in quantifying water flow paths and travel times in hydrological systems using tracer‐aided modeling. In snow‐influenced catchments, snowmelt produces a traceable isotopic signal, which differs from original snowfall isotopic composition because of isotopic fractionation in the snowpack. These fractionation processes in snow are relatively well understood, but representing their spatiotemporal variability in tracer‐aided studies remains a challenge. We present a novel, parsimonious modeling method to account for the snowpack isotope fractionation and estimate isotope ratios in snowmelt water in a fully spatially distributed manner. Our model introduces two calibration parameters that alone account for the isotopic fractionation caused by sublimation from interception and ground snow storage, and snowmelt fractionation progressively enriching the snowmelt runoff. The isotope routines are linked to a generic process‐based snow interception‐accumulation‐melt model facilitating simulation of spatially distributed snowmelt runoff. We use a synthetic modeling experiment to demonstrate the functionality of the model algorithms in different landscape locations and under different canopy characteristics. We also provide a proof‐of‐concept model test and successfully reproduce isotopic ratios in snowmelt runoff sampled with snowmelt lysimeters in two long‐term experimental catchment with contrasting winter conditions. To our knowledge, the method is the first such tool to allow estimation of the spatially distributed nature of isotopic fractionation in snowpacks and the resulting isotope ratios in snowmelt runoff. The method can thus provide a useful tool for tracer‐aided modeling to better understand the integrated nature of flow, mixing, and transport processes in snow‐influenced catchments.
Reply to comment by Ma and Zhang on “Rescaling the complementary relationship for land surface evaporation”
Authors: Crago Richard , Qualls Russell , Szilagyi Jozsef , Huntington Justin
Published: June 2017

Ma and Zhang (2017) note a concern they have with our rescaled Complementary Relationship (CR) for land surface evaporation when daily average wind speeds are very low (perhaps less than 1 m/s). We discuss conditions and specific formulations that lead to this concern, but ultimately argue that under these conditions, a key assumption behind the CR itself may not be satisfied at the daily time scale. Thus, careful consideration of the reliability of the CR is needed when wind speeds are very low.
Amino‐Functionalized ZIF‐7 Nanocrystals: Improved Intrinsic Separation Ability and Interfacial Compatibility in Mixed‐Matrix Membranes for CO2/CH4 Separation
Authors: Xiang Long , Sheng Luqian , Wang Chongqing , Zhang Lixiong , Pan Yichang , Li Yanshuo
Published: June 2017

Highly permeable and selective, as well as plasticization‐resistant membranes are desired as promising alternatives for cost‐ and energy‐effective CO2 separation. Here, robust mixed‐matrix membranes based on an amino‐functionalized zeolitic imidazolate framework ZIF‐7 (ZIF‐7‐NH2) and crosslinked poly(ethylene oxide) rubbery polymer are successfully fabricated with filler loadings up to 36 wt%. The ZIF‐7‐NH2 materials synthesized from in situ substitution of 2‐aminobenzimidazole into the ZIF‐7 structure exhibit enlarged aperture size compared with monoligand ZIF‐7. The intrinsic separation ability for CO2/CH4 on ZIF‐7‐NH2 is remarkably enhanced as a result of improved CO2 uptake capacity and diffusion selectivity. The incorporation of ZIF‐7‐NH2 fillers simultaneously makes the neat polymer more permeable and more selective, surpassing the state‐of‐the‐art 2008 Robeson upper bound. The chelating effect between metal (zinc) nodes of fillers and ester groups of a polymer provides good bonding, enhancing the mechanical strength and plasticization resistance of the neat polymer membrane. The developed novel ZIF‐7 structure with amino‐function and the resulting nanocomposite membranes are very attractive for applications like natural‐gas sweetening or biogas purification.
Controlling the Photonic Properties of Cholesteric Cellulose Nanocrystal Films with Magnets
Authors: Frka‐Petesic Bruno , Guidetti Giulia , Kamita Gen , Vignolini Silvia
Published: June 2017

The self‐assembly of cellulose nanocrystals is a powerful method for the fabrication of biosourced photonic films with a chiral optical response. While various techniques have been exploited to tune the optical properties of such systems, the presence of external fields has yet to be reported to significantly modify their optical properties. In this work, by using small commercial magnets (≈ 0.5–1.2 T) the orientation of the cholesteric domains is enabled to tune in suspension as they assemble into films. A detailed analysis of these films shows an unprecedented control of their angular response. This simple and yet powerful technique unlocks new possibilities in designing the visual appearance of such iridescent films, ranging from metallic to pixelated or matt textures, paving the way for the development of truly sustainable photonic pigments in coatings, cosmetics, and security labeling.
Copper‐Catalyzed Aerobic Oxygenation of Benzylpyridine N‐Oxides and Subsequent Post‐Functionalization
Authors: Sterckx Hans , Sambiagio Carlo , Médran‐Navarrete Vincent , Maes Bert U. W.
Published: June 2017

A copper‐catalyzed aerobic oxidation of benzylpyridine N‐oxides is reported. The N‐oxide moiety acts as a built‐in activator for the benzylic methylene oxidation, without requirement of additives. Reaction conditions were identified which suppress undesired benzoylpyridine formation via N‐deoxygenation involving intermolecular oxygen transfer. The versatility of the N‐oxide group of the benzoylpyridine N‐oxide reaction products for post‐functionalization of the pyridine ring is demonstrated through efficient C–C, C–N, C–O and C–Cl bond forming procedures, with both nucleophiles and electrophiles. Finally, the applicability of the new synthetic methodology is demonstrated in an alternative route towards the antihistaminic drug Acrivastine via three consecutive N‐oxide activated C–H functionalization processes, starting from picoline N‐oxide.

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VO2‐Based Reconfigurable Antenna Platform with Addressable Microheater Matrix
Authors: Gerislioglu Burak , Ahmadivand Arash , Karabiyik Mustafa , Sinha Raju , Pala Nezih
Published: June 2017

This study reports on a reconfigurable antenna platform based on vanadium dioxide (VO2), a phase‐change material (PCM) with low transition temperature, integrated with an addressable microheater matrix. For the first time, it is shown that an entire planar antenna can be thermally reconfigured virtually to any pattern by switching the phase of the selected regions of the VO2 layer from insulator to metallic state by indirect thermal stimuli generated by individually addressable nichrome resistive microheaters. Careful selection of the individual pixels to start the phase transition from insulator (OFF) to metallic (ON) state allows creating different antenna patterns with unique resonance properties. Reconfiguring the antenna into different patterns, operating frequency can be tuned from C‐band (4–8 GHz) to X‐band (8–12 GHz), and S‐band (2–4 GHz) frequencies which cover the entire ultra wideband spectrum (3.1–10.6 GHz). The proposed approach provides a promising platform for designing monolithically integrated reconfigurable antennas, radio frequency devices, and circuits for various applications.
Progressive SCAR14 with unclear speech, developmental delay, tremor, and behavioral problems caused by a homozygous deletion of the SPTBN2 pleckstrin homology domain
Authors: Yıldız Bölükbaşı Esra , Afzal Muhammad , Mumtaz Sara , Ahmad Nafees , Malik Sajid , Tolun Aslıhan
Published: June 2017

We report on nine members of a consanguineous Pakistani family with primary presentation of intellectual disability, developmental delay, limb and gait ataxia, behavioral and speech problems, and tremor. By linkage mapping and exome sequencing we identified novel homozygous splicing variant c.6375‐1G>C in SPTBN2. To date, only two other SPTBN2 mutations with recessive pattern of inheritance causing SCAR14 (spinocerebellar ataxia, autosomal recessive 14) that manifest with developmental ataxia and cognitive impairment, or cerebellar ataxia, mental retardation, and pyramidal signs have been reported. The mutation we identified is predicted to lead to the deletion of just the pleckstrin homology domain; thus, the earlier onset and more progressive nature of the disease in the presented family, as compared to earlier reports, were unexpected. No other mutation that could possibly explain the features that were unusual for SCAR14—arched palate, limb hypotonia, climacophobia, and behavioral problems—was identified. The disease was more severe in males than females. Our findings expand the recessive SPTBN2 mutation phenotype. We also review SPTBN2 mutation phenotypes. The gene encodes beta‐III spectrin, which forms tetramers with alpha‐II spectrin. The manifestations of this third recessive mutation suggest that for recessive mutations either no mutant protein is synthesized because the transcript is subject to nonsense‐mediated decay or the mutant protein does not bind membrane proteins and, thus, does not exert a negative effect in heterozygotes, whereas the dominant mutations causing SCA5 form defective tetramers that compete with the native tetramers in binding membrane proteins, but are unable to anchor them.
A Stretchable Electrochemical Sensor for Inducing and Monitoring Cell Mechanotransduction in Real Time
Authors: Liu Yan‐Ling , Qin Yu , Jin Zi‐He , Hu Xue‐Bo , Chen Miao‐Miao , Liu Rong , Amatore Christian , Huang Wei‐Hua
Published: June 2017

Existing methods offer little direct and real‐time information about stretch‐triggered biochemical responses during cell mechanotransduction. A novel stretchable electrochemical sensor is reported that takes advantage of a hierarchical percolation network of carbon nanotubes and gold nanotubes (CNT‐AuNT). This hybrid nanostructure provides the sensor with excellent time‐reproducible mechanical and electrochemical performances while granting very good cellular compatibility, making it perfectly apt to induce and monitor simultaneously transient biochemical signals. This is validated by monitoring stretch‐induced transient release of small signaling molecules by both endothelial and epithelial cells cultured on this sensor and submitted to stretching strains of different intensities. This work demonstrates that the hybrid CNT‐AuNT platform offers a versatile and highly sensitive way to characterize and quantify short‐time mechanotransduction responses.
The fabrication of iron oxide nanoparticle‐nanofiber composites by electrospinning and their applications in tissue engineering
Authors: Mortimer Chris J. , Wright Chris J.
Published: June 2017

This paper reviews the use of iron oxide nanoparticle‐nanofiber composites in tissue engineering with a focus on the electrospinning technique. Electrospinning is an established method of scaffold fabrication offering a number of key advantages which include its facile nature, with electrospun materials offering a high surface area to volume ratio, potential for the release of drugs and antimicrobials, controllable fiber diameters and high porosity and permeability. A number of different techniques for the preparation of iron oxide nanoparticles including their functionalization are discussed along with their applications in the biomedical field. The review then focusses on the fabrication of nanoparticle‐nanofiber composite scaffolds formed using electrospinning. The advantages and disadvantages of current fabrication techniques are discussed including the fabrication of nanofibers using pre‐synthesized nanoparticles and post‐treatment synthesized nanoparticles. We demonstrate that emerging in‐situ synthesis techniques show promise by offering a reduced number of steps and simpler procedures for the production of magnetic scaffolds. These scaffolds have a number of applications in tissue engineering, allowing for improved bone and tissue repair.
Molecular Tools for Facilitative Carbohydrate Transporters (Gluts)
Authors: Tanasova Marina , Fedie Joseph R.
Published: June 2017

Facilitative carbohydrate transporters—Gluts—have received wide attention over decades due to their essential role in nutrient uptake and links with various metabolic disorders, including diabetes, obesity, and cancer. Endeavors directed towards understanding the mechanisms of Glut‐mediated nutrient uptake have resulted in a multidisciplinary research field spanning protein chemistry, chemical biology, organic synthesis, crystallography, and biomolecular modeling. Gluts became attractive targets for cancer research and medicinal chemistry, leading to the development of new approaches to cancer diagnostics and providing avenues for cancer‐targeting therapeutics. In this review, the current state of knowledge of the molecular interactions behind Glut‐mediated sugar uptake, Glut‐targeting probes, therapeutics, and inhibitors are discussed.
Li/MgO Catalysts Doped with Alio‐valent Ions. Part I: Structure, Composition, and Catalytic Properties
Authors: Arndt Sebastian , Simon Ulla , Kiefer Klaus , Otremba Torsten , Siemensmeyer Konrad , Wollgarten Markus , Berthold Almuth , Schmidt Franziska , Görke Oliver , Schomäcker Reinhard , Dinse Klaus‐Peter
Published: June 2017

Doping of Li/MgO with additional metal ions is suggested leading to an improved system with respect to the catalytic performance and stability when used for oxidative coupling of methane. We used Gd and Fe as dopants and characterized the resulting materials, showing that Fe seems to be completely and Gd partly incorporated into the MgO lattice. The catalytic performance is improved in most cases, but all materials still suffer from severe deactivation. A loss of Li is observed when being used under reaction conditions, but this Li loss is retarded for Fe‐Li/MgO as compared to undoped Li/MgO.
Ni/Fe Ratio Dependence of Catalytic Activity in Monodisperse Ternary Nickel Iron Phosphide for Efficient Water Oxidation
Authors: Tang Kai , Wang Xianfu , Wang Mengfan , Xie Yiming , Zhou Jinqiu , Yan Chenglin
Published: June 2017

Electrochemical water splitting is an effective way to obtain hydrogen fuel as a clean and renewable energy source. However, a major challenge is to accelerate the sluggish oxygen evolution reaction (OER) kinetics with a multistep proton‐coupled electron‐transfer process. Transition metal Ni‐ and Co‐based composites have been developed to replace expensive and scare noble metal based OER catalysts. So far, layered NiFe double hydroxide represents the best OER activity among all Ni‐ and Co‐based oxides. Herein, monodispersed ternary (Ni1‐xFex)12P5 nanocrystalline materials with tunable Ni/Fe ratios are reported as highly efficient OER electrocatalysts, exhibiting activity and stability surpassing noble metal OER catalysts including RuO2, IrO2, and superior to nickel phosphides, layered nickel‐iron double hydroxides, and other NiFe‐based OER catalysts. X‐ray photoelectron spectroscopy (XPS) studies reveals that enhanced charge transfer from the foreign metal (Fe) to the host (Ni) to P atoms and a strong synergistic effect exist in the composite (Ni1‐xFex)12P5 electrocatalysts, thus rendering the as‐prepared (Ni1‐xFex)12P5 nanocrystalline compounds (NCs) with a Ni/Fe ratio of 0.51/0.49, the highest OER activity with a small onset potential of 125 mV, a low Tafel slope of 39 mV dec−1, and a low overpotential of 216 mV, to achieve 20 mA cm−2 in an alkaline medium electrolyte (1.0 M KOH).
Constructing an Atomic Layer Pt Electrocatalyst with a Concave Curved Surface for the Oxygen Reduction Reaction
Authors: Li Jian , Gao Yong‐Fu , Yin Hui‐Ming
Published: June 2017

One of the strategic objectives in fuel cell technologies is to develop oxygen reduction reaction (ORR) catalysts with high activity, stability and, moreover, a low Pt loading. Computational results have indicated that surfaces or nanostructures with concave defects exhibit higher ORR activity than convex ones. Here, atomic layers of Pt were epitaxially coated on nanoporous gold (NPG) for the unique surface structure, both with convex or concave curvatures of the NPG. Outstanding ORR activities were revealed on Pt overlayers who copied the substrate's surface features. Furthermore, ascribed to the adverse impacts of tensile Pt lattice on gold, an optimized specific activity has been found as a function of the increasing Pt atomic layers. Pt coating with three atomic layers on NPG (NPG−Pt3) shows the best specific activity with an approximate 9‐fold improvement with respect to commercial Pt/C, as well as a 10‐fold enhancement in mass activity at 0.9 V versus a reversible hydrogen electrode.
Linking ReI and PtII Chromophores with Aminopyridines: A Simple Route to Achieve a Complicated Photophysical Behavior
Authors: Kisel Kristina S. , Melnikov Alexei S. , Grachova Elena V. , Hirva Pipsa , Tunik Sergey P. , Koshevoy Igor O.
Published: June 2017

The bifunctional aminopyridine ligands H2N‐(CH2)n‐4‐C5H4N (n=0, L1; 1, L2; 2, L3) have been utilized for the preparation of the rhenium complexes [Re(phen)(CO)3(L1–L3)]+ (1–3; phen=phenanthroline). Complexes 2 and 3 with NH2‐coordinated L2 and L3, respectively, were coupled with cycloplatinated motifs {Pt(ppy)Cl} and {Pt(dpyb)}+ (ppy=2‐phenylpyridine, dpyb=dipyridylbenzene) to give the bimetallic species [Re(phen)(CO)3(μ‐L2/L3)Pt(ppy)Cl]+ (4, 6) and [Re(phen)(CO)3(μ‐L2/L3)Pt(dpyb)]2+ (5, 7). In solution, complexes 4 and 6 show 3MLCT {Re}‐based emission at 298 K, which changes to the 3IL(ppy) state at 77 K. The photophysical properties of compounds 5 and 7 display a pronounced concentration dependence, presumably due to the formation of bimolecular aggregates. Analysis of the spectroscopic data, combined with TD‐DFT simulations, suggest that unconventional heteroleptic {Re(phen)}⋅⋅⋅{Pt(dpyb)} π–π stacking operates as the driving force for ground‐state association. The latter, together with intra‐ and intermolecular energy‐transfer processes, determines the appearance of multiple emission bands and results in nonlinear relaxation kinetics of the excited states.
Preparation and evaluation of regioselectively substituted amylose derivatives for chiral separations
Authors: Tang Shouwan , Jin Zhaolei , Sun Baishen , Wang Fang , Tang Wenyuan
Published: June 2017

Six novel regioselectively substituted amylose derivatives with a benzoate at 2‐position and two different phenylcarbamates at 3‐ and 6‐positions were synthesized and their structures were characterized by 1H nuclear magnetic resonance (NMR) spectroscopy. Their enantioseparation abilities were then examined as chiral stationary phases (CSPs) for high‐performance liquid chromatography (HPLC) after they were coated on 3‐aminopropyl silica gels. Investigations indicated that the substituents at the 3‐ and 6‐positions played an important role in chiral recognition of these amylose 2‐benzoate serial derivatives. The derivatives demonstrated characteristic enantioseparation and some racemates were better resolved on these derivatives than on Chiralpak AD, which is one of the most efficient CSPs, utilizing coated amylose tris(3,5‐dimethylphenylcarbamate) as the chiral selector. Among the derivatives prepared, amylose 2‐benzoate‐3‐(phenylcarbamate/4‐methylphenylcarbamate)‐6‐(3,5‐dimethylphenylcarbamate) exhibited chiral recognition abilities comparable to that of Chiralpak AD and may be useful CSPs in the future. The effect of mobile phase on chiral recognition was also studied. In general, with the decreased concentration of 2‐propanol, better resolutions were obtained with longer retention times. Moreover, when ethanol was used instead of 2‐propanol, poorer resolutions were often achieved. However, in some cases, improved enantioselectivity was achieved with ethanol rather than 2‐propanol as the mobile phase modifier.
Performance evaluation of GPU parallelization, space‐time adaptive algorithms, and their combination for simulating cardiac electrophysiology
Authors: Sachetto Oliveira Rafael , Martins Rocha Bernardo , Burgarelli Denise , Meira Wagner , Constantinides Christakis , Weber dos Santos Rodrigo
Published: June 2017

The use of computer models as a tool for the study and understanding of the complex phenomena of cardiac electrophysiology has attained increased importance nowadays. At the same time, the increased complexity of the biophysical processes translates into complex computational and mathematical models. To speed up cardiac simulations and to allow more precise and realistic uses, 2 different techniques have been traditionally exploited: parallel computing and sophisticated numerical methods. In this work, we combine a modern parallel computing technique based on multicore and graphics processing units (GPUs) and a sophisticated numerical method based on a new space‐time adaptive algorithm. We evaluate each technique alone and in different combinations: multicore and GPU, multicore and GPU and space adaptivity, multicore and GPU and space adaptivity and time adaptivity. All the techniques and combinations were evaluated under different scenarios: 3D simulations on slabs, 3D simulations on a ventricular mouse mesh, ie, complex geometry, sinus‐rhythm, and arrhythmic conditions. Our results suggest that multicore and GPU accelerate the simulations by an approximate factor of 33×, whereas the speedups attained by the space‐time adaptive algorithms were approximately 48. Nevertheless, by combining all the techniques, we obtained speedups that ranged between 165 and 498. The tested methods were able to reduce the execution time of a simulation by more than 498× for a complex cellular model in a slab geometry and by 165× in a realistic heart geometry simulating spiral waves. The proposed methods will allow faster and more realistic simulations in a feasible time with no significant loss of accuracy.
Fabrication of BiOI Hierarchical Microspheres with Efficient Photocatalysis for Methylene Blue and Phenol Removal
Authors: Wang X. J. , Song Y. Q. , Hou J. Y. , Chen X. N.
Published: June 2017

BiOI hierarchical microspheres were synthesized by a solvothermal method. The different ratio of the amount of substance (Bi:I) drastically affects the feature that is embodied in multiaspect, such as crystallinity, morphological characteristics, component content, specific surface area and band gap width. These dissimilarities exert a great influence on photocatalytic performance. Ethylene glycol acts as soft template to guide the generation of the hierarchical microspheres. The presence of methanol has a positive effect on uniformity of reaction system in physical and chemical properties, because of its easy dispersibility and intersolubility. With interaction of mixed solvent, it leads to generate the uniform microspheres. The as‐received samples are characterized by X‐ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy dispersive spectroscopy(EDS), N2 adsorption‐desorption, UV–vis diffuse reflectance spectroscopy (DRS), X‐ray photoelectron spectroscopy (XPS), and fluorescence spectrophotometer. The formation of BiOI hierarchical microspheres were discussed with variational ratio of the amount of substance in mixed alcohol. To evaluate photocatalysis of as‐prepared BiOI, the methylene blue and phenol were exposed to visible light, which indicated degradation efficiency up to 98.09% just in 50 min and 94.14% within 6 h. The result shows that BiOI hierarchical microsphere is a promising photocatalyst in practical application.
Factors contributing to the accumulation of reproductive isolation: A mixed model approach
Authors: Castillo Dean M.
Published: June 2017

The analysis of large datasets describing reproductive isolation between species has been extremely influential in the study of speciation. However, the statistical methods currently used for these data limit the ability to make direct inferences about the factors predicting the evolution of reproductive isolation. As a result, our understanding of iconic patterns and rules of speciation rely on indirect analyses that have clear statistical limitations. Phylogenetic mixed models are commonly used in ecology and evolution, but have not been applied to studies of reproductive isolation. Here I describe a flexible framework using phylogenetic mixed models to analyze data collected at different evolutionary scales, to test both categorical and continuous predictor variables, and to test the effect of multiple predictors on rates and patterns of reproductive isolation simultaneously. I demonstrate the utility of this framework by re‐analyzing four classic datasets, from both animals and plants, and evaluating several hypotheses that could not be tested in the original studies: In theDrosophilaand Bufonidae datasets, I found support for more rapid accumulation of reproductive isolation in sympatric species pairs compared to allopatric species pairs. UsingSileneandNolana, I found no evidence supporting the hypothesis that floral differentiation elevates postzygotic reproductive isolation. The faster accumulation of postzygotic isolation in sympatry is likely the result of species coexistence determined by the level of postzygotic isolation between species. In addition, floral trait divergence does not appear to translate into pleiotropic effects on postzygotic reproductive isolation. Overall, these methods can allow researchers to test new hypotheses using a single statistical method, while remedying the statistical limitations of several previous methods.
Evolutionary responses to a changing climate: Implications for reindeer population viability
Authors: Bårdsen Bård‐Jørgen
Published: June 2017

If we want to understand how climate change affects long‐lived organisms, we must know how individuals allocate resources between current reproduction and survival. This trade‐off is affected by expected environmental conditions, but the extent to which density independent (DI) and density dependent (DD) processes interact in shaping individual life histories is less clear. Female reindeer (or caribou: Rangifer tarandus) are a monotocous large herbivore with a circumpolar distribution. Individuals that experience unpredictable and potentially harsh winters typically adopt risk averse strategies where they allocate more resources to building own body reserves during summer and less to reproduction. Such a strategy implies that the females do not reproduce or that they produce fewer or smaller offspring. A risk averse strategy thus results in females with large autumn body reserves, which is known to increase their survival probabilities if the coming winter is harsh. In contrast, females experiencing predictable winters may adopt a more risk prone strategy in which they allocate more resources to reproduction as they do not need as many resources to buffer potentially adverse winter conditions. This study uses a seasonal state‐dependent model showing that DD and DI processes interact to affect the evolution of reproductive strategies and population dynamics for reindeer. The model was run across a wide range of different winter climatic scenarios: One set of simulations where the average and variability of the environment was manipulated and one set where the frequency of good and poor winters increased. Both reproductive allocation and population dynamics of reindeer were affected by a combination of DI and DD processes even though they were confounded (harsh climates resulted in lowered density). Individual strategies responded, in line with a risk sensitive reproductive allocation, to climatic conditions and in a similar fashion across the two climatic manipulations.
Fluorescent Polypyrrole Nanospheres – Synthesis and Properties of “Wireless” Redox Probes
Authors: Kłucińska Katarzyna , Jaworska Ewa , Maksymiuk Krzysztof , Michalska Agata
Published: June 2017

In this work a novel concept of monitoring of occurrence of redox reactions between conducting polymer nanospheres and redox species in a solution is proposed. The redox process is monitored in the emission mode (without wiring of the probe to an electrochemical measuring set‐up) as a change in emission spectrum of a dye (not participating in the redox process itself) but reporting the alteration of properties of highly sensitive conducting polymer nanoparticles. This approach is possible due to applied unique method of synthesis of conducting polymers nanospheres of highly active, unblocked surface. Thus the nanospheres redox state is affected by the solution redox potential, leading to change of their properties. If solvatochromic probe of sufficiently high brightness (pyrene) is present in nanospheres, a redox reaction between the conducting polymer and solution can be observed as change of emission spectrum of the probe. Thus a localized redox potential optical probe can be obtained. The emission properties of the dye incorporated were preserved in the nanospheres, moreover, the emission spectrum of the probe was affected by the change in redox potential of the solution, thus influencing the redox state and ultimately the properties of the conducting polymer. The emission changes observed were dependent on ion‐exchange properties of polypyrrole, i.e. depending on the dopant ions present in the polymer, the sensitivity of the optical probe can be tuned.
A Phos‐tag‐based micropipette‐tip method for rapid and selective enrichment of phosphopeptides
Authors: Yuan Elena Tianfei , Ino Yoko , Kawaguchi Maho , Kimura Yayoi , Hirano Hisashi , Kinoshita‐Kikuta Emiko , Kinoshita Eiji , Koike Tohru
Published: June 2017

Phosphorylated peptides are attractive targets in the study of the phosphoproteome. Here, we introduce a simple and convenient micropipette‐tip method for the separation of phosphorylated and nonphosphorylated peptides by using a phosphate‐binding zinc(II) complex of 1,3‐bis(pyridin‐2‐ylmethylamino)propan‐2‐olate (Phos‐tag). A 200‐μL micropipette tip containing 10 μL of swollen agarose beads functionalized with Phos‐tag moieties was prepared. All steps in the phosphate‐affinity separation (binding, washing, and elution) were conducted by using aqueous buffers at neutral pH values. The entire separation protocol required less than 30 min per sample. By means of three independent separation experiments, followed by mass spectrometric (MS) analyses, we identified 1,649 non‐redundant phosphopeptides from the lysates of human embryonic kidney cells (the peptides sample derived from 25 μg proteins per an MS analysis). The average ratio of identified phosphopeptides to total peptides in the respective experiments was >90%, showing a high selectivity. Furthermore, the high correlation between the triplicate analyses was confirmed by scatter plots based on the normalized abundance of each peptide, as calculated by a label‐free peptide relative quantification analysis in Progenesis QI. This micropipette‐tip method would be thus used preferentially as an alternative to existing tools for the reliable enrichment of phosphopeptides.
Development of biotic ligand model–based freshwater aquatic life criteria for lead following US Environmental Protection Agency guidelines
Authors: DeForest David K. , Santore Robert C. , Ryan Adam C. , Church Brian G. , Chowdhury M. Jasim , Brix Kevin V.
Published: June 2017

The US Environmental Protection Agency's (USEPA's) current ambient water quality criteria (AWQC) for lead (Pb) in freshwater were developed in 1984. The criteria are adjusted for hardness, but more recent studies have demonstrated that other parameters, especially dissolved organic carbon (DOC) and pH, have a much stronger influence on Pb bioavailability. These recent studies have been used to support development of a biotic ligand model (BLM) for Pb in freshwater, such that acute and chronic Pb toxicity can be predicted over a wide range of water chemistry conditions. Following USEPA guidelines for AWQC development and using a methodology consistent with that used by the USEPA in developing its recommended BLM-based criteria for copper in 2007, we propose acute and chronic BLM-based AWQC for Pb in freshwater. In addition to the application of the BLM approach that can better account for site-specific Pb bioavailability, the toxicity data sets presented are much more robust than in 1984, and there are now sufficient chronic Pb toxicity data available that use of an acute-to-chronic ratio is no longer necessary. Over a range of North American surface waters with representative water chemistry conditions, proposed acute BLM-based Pb criteria ranged from approximately 20 to 1000 μg/L and chronic BLM-based Pb criteria ranged from approximately 0.3 to 40 μg/L. The lowest criteria were for water with low DOC (1.2 mg/L), pH (6.7), and hardness (4.3 mg/L as CaCO3), whereas the highest criteria were for water with high DOC (9.8 mg/L), pH (8.2), and hardness (288 mg/L as CaCO3). Environ Toxicol Chem 2017;36:2965–2973. © 2017 SETAC
Widespread occurrence and potential for biodegradation of bioactive contaminants in Congaree National Park, USA
Authors: Bradley Paul M. , Battaglin William A. , Clark Jimmy M. , Henning Frank P. , Hladik Michelle L. , Iwanowicz Luke R. , Journey Celeste A. , Riley Jeffrey W. , Romanok Kristin M.
Published: June 2017

Organic contaminants with designed molecular bioactivity, such as pesticides and pharmaceuticals, originate from human and agricultural sources, occur frequently in surface waters, and threaten the structure and function of aquatic and terrestrial ecosystems. Congaree National Park in South Carolina (USA) is a vulnerable park unit due to its location downstream of multiple urban and agricultural contaminant sources and its hydrologic setting, being composed almost entirely of floodplain and aquatic environments. Seventy-two water and sediment samples were collected from 16 sites in Congaree National Park during 2013 to 2015, and analyzed for 199 and 81 targeted organic contaminants, respectively. More than half of these water and sediment analytes were not detected or potentially had natural sources. Pharmaceutical contaminants were detected (49 total) frequently in water throughout Congaree National Park, with higher detection frequencies and concentrations at Congaree and Wateree River sites, downstream from major urban areas. Forty-seven organic wastewater indicator chemicals were detected in water, and 36 were detected in sediment, of which approximately half are distinctly anthropogenic. Endogenous sterols and hormones, which may originate from humans or wildlife, were detected in water and sediment samples throughout Congaree National Park, but synthetic hormones were detected only once, suggesting a comparatively low risk of adverse impacts. Assessment of the biodegradation potentials of 8 14C-radiolabeled model contaminants indicated poor potentials for some contaminants, particularly under anaerobic sediments conditions. Environ Toxicol Chem 2017;36:3045–3056. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Discovery of Mesoproterozoic kimberlite from Dörbed Banner, Inner Mongolia and its tectonic significance
Authors: Zhou Zhiguang , Wang Guosheng , Di Yong‐jun , Gu Yong‐chang , Zhang Da , Zhu Wei‐ping , Liu Changfeng , Wu Chen , Li Hongying , Chen Li‐zhen
Published: June 2017

Porphyritic olivine kimberlitic breccia, discovered in the Dörbed Banner of Inner Mongolia, Western China, is referred to as Longtou Shan Kimberlite in our study. This kimberlite occurs as a pipe in the Halahuogete Formation of Bayan Obo Group. Zircon U–Pb ages of Longtou Shan Kimberlite reveals a Mesoproterozoic age of ~1,552 Ma, constraining the deposition age of Halahuogete Formation to the Mesoproterozoic. Compared with Mesoproterozoic kimberlite of the ancient landmass, it can be inferred that the North China Craton is a member of the Ur ancient continent of the Columbia supercontinent. Furthermore, according to the tectonic background of the Bayan Obo Group, we raise this possibility that “Bayan Obo Aulacogen” should be renamed the “Bayan Obo Continental Rift.”
The role of child temperament on low‐income preschool children's relationships with their parents and teachers
Authors: Acar Ibrahim H. , Torquati Julia C. , Encinger Amy , Colgrove Amy
Published: June 2017

The current study examined the associations between low‐income preschool children's temperament (reactive and regulatory) and their relationships with parents and teachers. In particular, we focused on the moderating role of regulatory temperament on reactive temperament in the prediction of closeness and conflict with parents and teachers. Two hundred ninety‐one children (M = 53.88 months, SD = 6.44 months), their parents, and teachers from 3 different preschools serving low‐income children in 2 midwestern cities in the United States participated. Parents reported on temperament and parent–child relationships, and teachers reported on teacher–child relationships. Hierarchical regression models using SAS PROC MIXED were employed to allow for nesting of children within classrooms. After controlling for child age, gender, ethnicity, and parent education, children's reactive temperament was negatively associated with parent–child closeness and positively associated with parent–child conflict and teacher–child conflict. Children's regulatory temperament was positively related to teacher–child closeness and negatively associated with teacher–child conflict. Regulatory temperament moderated the association between reactive temperament and teacher–child closeness. These findings suggest that although reactive temperament potentially undermines closeness in relationships with teachers, regulatory temperament can buffer the influence of reactive temperament on teacher–child closeness.

Highlights

This study examined the association between children's temperament and their relationships with parents and teachers.

Reactive temperament was positively associated with parent/teacher–child conflict and negatively associated with parent–child closeness. Regulatory temperament was a moderator for the association between reactive temperament and teacher–child closeness.

Improving children's regulatory temperament may be helpful for children with the reactive temperament to have better social relationships with their teachers.
Patterns of emotional availability between mothers and young children: Associations with risk factors for borderline personality disorder
Authors: Trupe Rebecca D. , Macfie Jenny , Skadberg Rebecca M. , Kurdziel Gretchen
Published: June 2017

Emotional availability (EA) characterizes a warm, close relationship between caregiver and child. We compared patterns (clusters) of EA on risk factors, including those for borderline personality disorder (BPD). We sampled 70 children aged 4 to 7 years from low socio‐economic backgrounds: 51% of whose mothers had BPD. We coded filmed interactions for EA: mothers' sensitivity, structuring, non‐intrusiveness, non‐hostility, and children's responsiveness to, and involvement of, mothers. We additionally coded children's over‐responsiveness and over‐involvement. Using person‐centred analyses, we identified four clusters: high functioning, low functioning, asynchronous (mothers above average on two of four dimensions and children below), and below average. Mothers in the low‐functioning cluster had lower income, less social support, more of the borderline feature of negative relationships, and more depression than did mothers in the high‐functioning cluster. The children in the low‐functioning group had more risk factors for BPD (physical abuse, neglect, and separation from, or loss of caregivers, and negative narrative representations of the mother–child relationship in their stories) than did children in the high‐functioning group. The asynchronous group included older girls who were over‐responsive and over‐involving with their mothers in an apparent role reversal. Interventions targeting emotional availability may provide a buffer for children facing cumulative risks and help prevent psychopathology.

Highlights

This paper investigated how mother‐child emotional availability (warmth and closeness) relates to risk factors for borderline personality disorder, including mother‐child role reversal.

In filmed mother‐child interactions, low emotional availability was associated with risk for borderline personality disorder and role reversal was more likely for older girls.

Findings support the cumulative risk hypothesis and may inform interventions to improve mother‐child emotional availability to prevent the development of psychopathology.
Photocatalytic interaction of aminophylline–riboflavin leads to ROS‐mediated DNA damage and cell death: A novel phototherapeutic mechanism for cancer
Authors: Khan Saniyya , Naseem Imrana
Published: June 2017

The accompanied tissue devastation and systemic toxicity of chemotherapy has shifted the quest for having an effective and palliative cancer therapy towards photodynamic therapy (PDT). Riboflavin (Rf), an essential micronutrient is emerging as a potent tool of PDT, due to its excellent photosensitizing properties. It can be used as an efficient adjuvant for various anticancer drugs. The hemolytic and proteolytic effect of photoilluminated aminophylline (Am), a xanthine derivative, and Rf is well documented in literature. In this study, using human peripheral lymphocytes we have demonstrated the strong pro‐oxidant effects of photocatalytic interaction between Am and Rf. The photo degradation kinetics of Am in the presence of Rf was monitored using UV spectroscopy, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. The resultant pro‐oxidant action of Am was monitored through various assays like lipid peroxidation, protein carbonylation, and reactive oxygen species (ROS) generation. Furthermore, the cytotoxic potential of this system was studied using comet and MTT (3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide) assay. Treated lymphocytes were visualized using fluorescence and scanning electron microscopy to further validate apoptosis. ROS scavengers ameliorated the oxidative damage caused by this system suggesting pivotal role of ROS in causing apoptotic cell death. As cancer cells exhibit increased absorption of Rf as well as are very sensitive in any further ROS level increment, this putative pathway can serve as an effective anodyne phototherapeutic strategy for cancer treatment. © 2017 IUBMB Life, 69(8):611–622, 2017