bluuebunny/crossref_metadata_2025 huggingface dataset:
Antifouling enhancement of PVDF membrane tethered with polyampholyte hydrogel layers
Authors: Shen Xiang , Yin Xuebin , Zhao Yiping , Chen Li
Published: March 2015

The preparation and property of antifouling poly(vinylidene fluoride) (PVDF) membrane tethered with polyampholyte hydrogel layers were described in this work. In fabricating these membranes, the [2‐(methacryloyloxy)ethyl] trimethylammonium chloride and 2‐acrylamide‐2‐methyl propane sulfonic acid monomers were grafted onto the alkali‐treated PVDF membrane to yield polyampholyte hydrogel layers via radical copolymerization with N,N′‐methylenebisacrylamide as crosslinking agent. The analyses of fourier transform infrared attenuated total reflection spectroscopy and X‐ray photoelectron spectroscopy confirm the covalent immobilization of polyampholyte hydrogel layer on PVDF membrane surface. The grafting density of polyampholyte hydrogel layer increases with the crosslinking agent growing. Especially for the membrane with a high grafting density, a hydrogel layer can be observed obviously, which results in the complete coverage of membrane pores. Because of the hydrophilic characteristic of grafted layer, the modified membranes show much lower protein adsorption than pristine PVDF membrane. Cycle filtration tests indicate that both the reversible and irreversible membrane fouling is alleviated after the incorporation of polyampholyte hydrogel layer into the PVDF membrane. This work provides an effective pathway of covalently tethering hydrogel onto the hydrophobic membrane surface to achieve fouling resistance. POLYM. ENG. SCI., 55:1367–1373, 2015. © 2015 Society of Plastics Engineers
Facile preparation of highly conductive, flexible, and strong carbon nanotube/polyaniline composite films
Authors: Xiao Hong‐Mei , Zhang Wei‐Dong , Na Li , Huang Gui‐Wen , Liu Yu , Fu Shao‐Yun
Published: March 2015

In general, the high electrical conductivity (EC) comes into conflict with the good flexibility and high strength of carbon nanotube (CNT)/polyaniline (PANI) composites. In other words, a high CNT content will bring about a high EC but lead to a low flexibility and strength due to the CNT‐constrained matrix deformation and CNT aggregation. In this work, a highly conductive, flexible and strong CNT/PANI composite film prepared via a facile solvent‐evaporation method is readily obtained by a cold stretching. The cold stretching is conducted at room temperature for the CNT/PANI film. It is observed that the cold stretching process leads to an unexpectedly enhanced EC. The as‐obtained EC of 231 S/cm is much higher than that (2–50 S/cm) of the previously reported CNT/PANI composite films. Meanwhile, the strength is obviously improved over that of the pure PANI film and the good flexibility is maintained to a high degree by the introduction of a proper CNT content. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1575–1585
Attracting and Retaining Foreign Highly Skilled Staff in Times of Global Crisis: a Case Study of Vancouver, British Columbia's Biotechnology Sector
Authors: Richardson Kathrine
Published: March 2015

How cities attract and retain hard‐won foreign talent in times of economic crisis is an under‐researched theme. This paper draws on surveys of firms and allied professionals in the Vancouver biotechnology sector to examine the strategies used to attract and retain highly skilled staff over a 10‐year period up to 2012. It argues that the foreign highly skilled within Vancouver's biotechnology sector were more prone to crisis at the level of the firm than they were directly vulnerable to the global financial recession of the early 2000s and 2008. In fact, these crises required firms interviewed to become highly dependent on local and regional auxiliary professionals such as human resource managers and professional immigration attorneys, in addition to spouses, in order to retain these highly skilled foreign professionals within the host city of Vancouver. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of spin–orbit coupling on actinium under pressure
Authors: Rubio‐Ponce A. , Rivera J. , Olguí n D.
Published: March 2015

Actinium (Ac) is a radioactive metal and the first element of the actinide series. At ambient conditions Ac crystallizes in the fcc lattice, however, up to date its phase diagram is unknown. In the present work, we have studied the structural and electronic properties of Ac under hydrostatic pressure assuming the fcc structure as well as three hypothetical structures, namely the hcp, bcc, and sc, and for pressures up to 100 GPa. From our calculations, we found only one structural transition allowed, from the fcc to hcp, our calculated pressure was 39.85 GPa. The calculations were performed by means of the full potential linearized augmented plane wave (FLAPW) method and the generalized gradient approximation (GGA) for the exchange–correlation energy, where we have included in our study the spin–orbit coupling which is important for heavy elements. The total energy results were fitted to the third order Birch–Murnaghan's equation of state.
Investigation of stress, defect structure and electrical conduction in large diameter III‐nitride epitaxy on silicon substrates
Authors: Chung G. , Loboda M. J. , Carlson E. , Ewoldt D. , Ng T. , Shepherd D.
Published: March 2015

The results of studies focused on understanding materials‐electrical correlations for GaN‐based films deposited on 150 mm diameter Si wafers in a batch MOCVD system are reported. A wide range of film stress and electrical conduction is observed at consistent and good X‐ray FWHM values. The vertical leakage currents show a strong asymmetry on the polarity of the bias voltage. Film stress (wafer bow) and impurity variations in the buffer layers show no correlation with leakage currents. Surface pit formation and conductive interfaces are critical to determine the leakage currents in buffer layers. TEM image confirms that surface pit stems from voids in Si substrate. The vertical leakage currents follow the Frenkel‐Poole conduction model at the trap energy of 0.7 eV. Vertical leakage currents measured in films can be reduced by a novel, post‐growth process. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High power blue AlGaInN LED chips with two‐level metallization
Authors: Zakheim D. A. , Itkinson G. V. , Kukushkin M. V. , Markov L. K. , Osipov O. V. , Pavluchenko A. S. , Smirnova I. P. , Bauman D. A.
Published: March 2015

In this paper, we report on the development and fabrication of high power LED chips based on AlGaInN. These chips are meant for flip‐chip mounting and have novel contact pad topology utilizing two‐level metallization with the intermediate dielectric isolation. The size and shape of highly reflective ITO/Ag‐based p‐type and Ti/Ag based n‐type contact pads were adjusted with the use of the numerical simulations of current spreading. As a result, the developed chip has 1 mm2 active area and series resistance as low as 0.3 Ω. The fabricated LEDs demonstrate emission power of 542 mW at 350 mA and the maximum external quantum efficiency equal to 60%. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron paramagnetic resonance studies of bulk Mg‐doped GaN grown by high nitrogen pressure solution method
Authors: Dashdorj J. , Willoughby W. R. , Zvanut M. E. , Bockowski M.
Published: March 2015

An acceptor‐related impurity was studied in bulk free standing GaN using electron paramagnetic resonance spectroscopy. Both undoped and Mg‐doped substrates grown by the high nitrogen pressure solution method were examined, but only the doped sample revealed the presence of an EPR‐detected center. Comparison with earlier work on p ‐type GaN films suggests that the defect is an acceptor, heavily compensated during growth. Photo‐EPR studies revealed a photo‐ionization threshold of 2.8 eV, which is interpreted as excitation of an electron from the acceptor to the conduction band. Based on the concentration and photo‐threshold, the EPR center detected in the HNPS doped samples is tentatively identified as Be, which SIMS measurements indicate is a trace impurity in the doped GaN sample. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kinetic Monte Carlo simulations of epitaxial growth of wurtzite GaN(0001)
Authors: Chugh Manjusha , Ranganathan Madhav
Published: March 2015

A lattice based kinetic Monte Carlo (kMC) simulation is developed to describe growth of GaN(0001) in conditions typical of a molecular beam epitaxy unit. Deposition and surface diffusion via attachment and detachment of atoms are the main processes considered in this model. The energy barriers for surface diffusion are estimated from ab‐initio density functional theory calculations.

From the ab‐initio calculations, we identify a rapid motion of N atoms attached to Ga adatoms. Preliminary kMC simulation results indicate that this motion allows N adatoms to move towards their preferred positions and thereby facilitate smooth growth prior to the formation of the protective Ga adlayer which is believed to promote smooth growth under Ga rich conditions. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SCM and SIMS investigations of unintentional doping in III‐nitrides
Authors: Kappers M. J. , Zhu T. , Sahonta S.‐L. , Humphreys C. J. , Oliver R. A.
Published: March 2015

Cross‐sectional scanning capacitance microscopy measurements of unintentionally doped model structures for InGaN quantum wells, GaN barriers and AlInN electron‐blocking layers showed n ‐type conductivity for the In‐containing layers. Secondary ion mass spectrometry indicated that oxygen impurities are the likely source of the electron density in the model layers. The n ‐type conductivity as well as the oxygen impurity level increases to ∼1018 cm‐3 for AlInN lattice‐matched to GaN. These results suggest that the background electron concentration due to oxygen impurities in indium‐containing layers needs to be considered in the design and theoretical modelling of device structures. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Effects of Pre‐Exercise Ginger Supplementation on Muscle Damage and Delayed Onset Muscle Soreness
Authors: Matsumura Melissa D. , Zavorsky Gerald S. , Smoliga James M.
Published: March 2015

Ginger possesses analgesic and pharmacological properties mimicking non‐steroidal antiinflammatory drugs. We aimed to determine if ginger supplementation is efficacious for attenuating muscle damage and delayed onset muscle soreness (DOMS) following high‐intensity resistance exercise. Following a 5‐day supplementation period of placebo or 4 g ginger (randomized groups), 20 non‐weight trained participants performed a high‐intensity elbow flexor eccentric exercise protocol to induce muscle damage. Markers associated with muscle damage and DOMS were repeatedly measured before supplementation and for 4 days following the exercise protocol. Repeated measures analysis of variance revealed one repetition maximum lift decreased significantly 24 h post‐exercise in both groups (p < 0.005), improved 48 h post‐exercise only in the ginger group (p = 0.002), and improved at 72 (p = 0.021) and 96 h (p = 0.044) only in the placebo group. Blood creatine kinase significantly increased for both groups (p = 0.015) but continued to increase only in the ginger group 72 (p = 0.006) and 96 h (p = 0.027) post‐exercise. Visual analog scale of pain was significantly elevated following eccentric exercise (p < 0.001) and was not influenced by ginger. In conclusion, 4 g of ginger supplementation may be used to accelerate recovery of muscle strength following intense exercise but does not influence indicators of muscle damage or DOMS. Copyright © 2015 John Wiley & Sons, Ltd.
California's Low‐Threat LUFT Site Closure Policy: Looking Forward
Authors: Hadley Paul W. , Arulanantham Ravi , Gandhi Deepa
Published: March 2015

California's regulatory agencies have historically been at the forefront of national efforts to address environmental concerns. In 2012, California's agency for addressing leaking underground fuel tanks (LUFTs) adopted a policy that identifies low‐threat conditions warranting closure of an LUFT case. That development clearly fulfills the role of risk management in the risk assessment–risk management paradigm inherent in environmental remediation. It also encourages identification of additional categories of sites and other circumstances that are “low threat” to develop similar guidance on closure to apply to those sites. ©2015 Wiley Periodicals, Inc.
In Situ Remediation of 1,4‐Dioxane Using Electrical Resistance Heating
Authors: Oberle Daniel , Crownover Emily , Kluger Mark
Published: March 2015

Recent regulatory changes need more challenging treatment goals for 1,4‐dioxane. However, significant treatment limitations exist in part due to the high solubility and low Henry's law constant of 1,4‐dioxane. Two case studies are reported with substantial 1,4‐dioxane concentration reductions through in situ thermal remediation via electrical resistance heating (ERH). Concentration reductions greater than 99.8 percent of 1,4‐dioxane have been observed in the field using ERH. Concentrations of 1,4‐dioxane in air and steam extracted by an ERH vapor recovery system have also been evaluated. Laboratory studies were conducted to further understand the mechanisms that enable ERH remediation of 1,4‐dioxane. Vapor liquid equilibrium studies in water and soil were conducted and utilized to develop an ERH treatment cost model for 1,4‐dioxane. Existing field data were correlated to the 1,4‐dioxane treatment cost model. Field observations and laboratory testing indicate steam stripping that occurs through ERH remediation is an effective treatment method for 1,4‐dioxane. ©2015 Wiley Periodicals, Inc.
Low‐Capacity Well Pairs for Treating Contaminated Groundwater in Homogeneous and Heterogeneous Aquifers
Authors: Hudak Paul F.
Published: March 2015

Groundwater remediation alternatives were simulated for homogeneous and heterogeneous aquifers with a numerical mass transport model. Low‐energy alternatives involved an injection–extraction well pair positioned along a downgradient linear transect. This transect was located 5 m from the contaminant plume and oriented perpendicular to the regional hydraulic gradient. Through numerous trials, for one homogeneous and three heterogeneous settings, the model identified an optimal spacing and minimum pumping rate for a well pair: (1) centered on the downgradient tip of the plume (best centered), and (2) anywhere along the downgradient transect (best overall). Results suggest that low‐energy well pairs are an effective means for containing and removing some contaminant plumes, and best‐performing configurations are generally not centered on the downgradient tip of the initial contaminant plume. ©2015 Wiley Periodicals, Inc.
Economic Project Risk Assessment in Remediation Projects Prior to Construction: Methodology Development and Case Study Application
Authors: Brinkhoff Petra , Norin Malin , Norrman Jenny , Rosén Lars , Ek Kristine
Published: March 2015

Probabilistic economic analysis, including uncertainty of probabilities and consequences of project risks, is not widely used in remediation projects. This article presents a project risk assessment (PRA) method to identify, quantify, and analyze risks in remediation projects. The suggested method is probabilistic and includes uncertainty analysis of input variables based on expert judgment. It was originally developed as a part of a sustainability assessment tool, but is viable as a stand‐alone tool for remediation projects. The method is applied to a case study: a former paint factory that is being redeveloped into a residential area. The PRA method is used for analyzing and comparing the project risks associated with four remediation options, all including excavation but with different degrees of onsite treatment. The result of the case study application shows which alternative has the lowest mean risk cost, the highest probability to have the lowest risk cost, and how the risk costs are distributed, but also, importantly, helps the user to prioritize between risk‐reduction measures. ©2015 Wiley Periodicals
Robust iterative learning control for systems with norm‐bounded uncertainties
Authors: Li Xuefang , Huang Deqing , Chu Bing , Xu Jian‐Xin
Published: March 2015

A new robust iterative learning control scheme is presented for state tracking control of nonlinear MIMO systems. The main characteristic of the proposed controller lies in its ability to deal with unstructured uncertainties that are norm‐bounded but not globally or locally Lipschitz continuous as usual. The classical resetting condition of iterative learning control is removed and replaced with more practical alignment condition. The class of systems to be considered is further extended to more general scenarios, in which input distribution uncertainties are included. In the end, an illustrative example is presented to demonstrate the efficacy of the proposed control scheme. Copyright © 2015 John Wiley & Sons, Ltd.
A high capacity data hiding algorithm for H.264/AVC video
Authors: Fallahpour Mehdi , Shirmohammadi Shervin , Ghanbari Mohammad
Published: March 2015

This article presents an information hiding algorithm for H.264/AVC video stream. It utilizes position of the last nonzero level of quantized discrete cosine transform block to embed information bits. Because only the high‐frequency levels are changed, it can guarantee a high peak signal‐to‐noise ratio and slight increase in bit rate after the watermark embedding. The extraction process is not complex; thus, the proposed technique is an excellent solution for real‐time applications such as broadcasting. Experimental results on several test sequences demonstrate that the proposed approach can realize blind extraction with real‐time performance; it also provides very high capacity, low distortion and increase in bit rate by about 0.5%. Copyright © 2015 John Wiley & Sons, Ltd.
Revisiting the role of the environment in the capabilities–financial performance relationship: A meta‐analysis
Authors: Karna Amit , Richter Ansgar , Riesenkampff Eberhard
Published: March 2015

Within the capabilities‐based view of the firm, there is debate about the relative importance of ordinary and dynamic capabilities for firm performance and about the extent to which their performance effects are contingent on environmental conditions. We meta‐analyze 115 studies to investigate the relationship between both ordinary and dynamic capabilities and the financial performance of firms in relatively stable versus changing environments. The results suggest that the performance effects of both types of capabilities are positive and similar in magnitude. Environmental dynamism reinforces the effects of both ordinary and dynamic capabilities. Furthermore, the two types of capabilities are closely associated. Our findings provide support for a moderate capabilities‐based view of the firm, rather than one that considers dynamic capabilities as superior to ordinary ones. Copyright © 2015 John Wiley & Sons, Ltd.
Activated K-Ras, but Not H-Ras or N-Ras, Regulates Brain Neural Stem Cell Proliferation in a Raf/Rb-Dependent Manner
Authors: Bender R. Hugh F. , Haigis Kevin M. , Gutmann David H.
Published: March 2015

Neural stem cells (NSCs) give rise to all the major cell types in the brain, including neurons, oligodendrocytes, and astrocytes. However, the intracellular signaling pathways that govern brain NSC proliferation and differentiation have been incompletely characterized to date. Since some neurodevelopmental brain disorders (Costello syndrome and Noonan syndrome) are caused by germline activating mutations in the RAS genes, Ras small GTPases are likely critical regulators of brain NSC function. In the mammalian brain, Ras exists as three distinct molecules (H-Ras, K-Ras, and N-Ras), each with different subcellular localizations, downstream signaling effectors, and biological effects. Leveraging a novel series of conditional-activated Ras molecule-expressing genetically engineered mouse strains, we demonstrate that activated K-Ras, but not H-Ras or N-Ras, expression increases brain NSC growth in a Raf-dependent, but Mek-independent, manner. Moreover, we show that activated K-Ras regulation of brain NSC proliferation requires Raf binding and suppression of retinoblastoma (Rb) function. Collectively, these observations establish tissue-specific differences in activated Ras molecule regulation of brain cell growth that operate through a noncanonical mechanism. Stem Cells  2015;33:1998–2010
Adult DRG Stem/Progenitor Cells Generate Pericytes in the Presence of Central Nervous System (CNS) Developmental Cues, and Schwann Cells in Response to CNS Demyelination
Authors: Vidal Marie , Maniglier Madlyne , Deboux Cyrille , Bachelin Corinne , Zujovic Violetta , Baron-Van Evercooren Anne
Published: March 2015

It has been proposed that the adult dorsal root ganglia (DRG) harbor neural stem/progenitor cells (NPCs) derived from the neural crest. However, the thorough characterization of their stemness and differentiation plasticity was not addressed. In this study, we investigated adult DRG-NPC stem cell properties overtime, and their fate when ectopically grafted in the central nervous system. We compared them in vitro and in vivo to the well-characterized adult spinal cord-NPCs derived from the same donors. Using micro-dissection and neurosphere cultures, we demonstrate that adult DRG-NPCs have quasi unlimited self-expansion capacities without compromising their tissue specific molecular signature. Moreover, they differentiate into multiple peripheral lineages in vitro. After transplantation, adult DRG-NPCs generate pericytes in the developing forebrain but remyelinating Schwann cells in response to spinal cord demyelination. In addition, we show that axonal and endothelial/astrocytic factors as well astrocytes regulate the fate of adult DRG-NPCs in culture. Although the adult DRG-NPC multipotency is restricted to the neural crest lineage, their dual responsiveness to developmental and lesion cues highlights their impressive adaptive and repair potentials making them valuable targets for regenerative medicine. Stem Cells  2015;33:2011–2024
TGFBIp regulates differentiation of EPC (CD133+c-kit+lin− cells) to EC through activation of the notch signaling pathway
Authors: Maeng Yong-Sun , Choi Yeon Jeong , Kim Eung Kweon
Published: March 2015

Endothelial progenitor cells (EPCs) in the circulatory system have been suggested to maintain vascular homeostasis and contribute to adult vascular regeneration and repair. These processes require that EPCs recognize the extracellular matrix (ECM), migrate, differentiate, and undergo tube morphogenesis. The ECM plays a critical role by providing biochemical and biophysical cues that regulate cellular behavior. Here, we tested the importance of transforming growth factor-beta-induced protein (TGFBIp) in regulation of the differentiation and angiogenic potential of human cord blood-derived EPCs (CD133+C-kit+Lin− cells). EPCs displayed increased endothelial differentiation when plated on TGFBIp compared to fibronectin. EPCs also exhibited increased adhesion and migration upon TGFBIp stimulation. Moreover, TGFBIp induced phosphorylation of the intracellular signaling molecules SRC, FAK, AKT, JNK, and ERK in EPCs. Using integrin-neutralizing antibodies, we showed that the effects of TGFBIp on EPCs are mediated by integrins α4 and α5. Furthermore, TGFBIp increased the adhesion, migration, and tube formation of CD34+ mouse bone marrow stem cells in vitro. Gene expression analysis of EPCs plated on TGFBIp revealed that EPCs stimulated by TGFBIp exhibit increased expression of Notch ligands, such as delta-like 1 (DLL1) and Jagged1 (JAG1), through nuclear factor-kappa B signaling activation. Collectively, our findings demonstrate, for the first time, that locally generated TGFBIp at either wounds or tumor sites may contribute to differentiation and angiogenic function of EPCs by augmenting the recruitment of EPCs and regulating the expression of endothelial genes DLL1 and JAG1. Stem Cells  2015;33:2052–2062
Reconceptualizing the Self Phenomenon: Toward an Emic Conception of the Self
Authors: Zhao Shanyang
Published: March 2015

In sociology, the self has been conceptualized as either self‐concept or the process of self‐reflectivity. Both notions of the self have been traced to the early thinkers—William James, Charles H. Cooley, and George H. Mead—who laid the foundation for the scientific study of the self phenomenon. In this article, I propose a revised conception of the self based on a re‐reading of the classics. I argue that the self is related to but not the same as self‐concept or the process of self‐reflectivity. The self is an emic object, that is, the entity that one takes oneself to be. More specifically, the self is the empirical existence of an individual perceived by the individual to be his or her own. As the identity the individual finds in his or her existence in a world shared with others, the self is a product of both self‐reflection and self‐enactment. Implications of this reconceptualization for some broad issues related to the self phenomenon are also discussed.
In situ reduction and functionalization of graphene oxide to improve the tribological behavior of a phenol formaldehyde composite coating
Authors: Yang Mingming , Zhang Zhaozhu , Zhu Xiaotao , Men Xuehu , Ren Guina
Published: March 2015

The development of a phenol formaldehyde/graphene (PF-graphene) composite coating with high performance is desirable but remains a challenge, because of the ultrahigh surface area and surface inertia of the graphene. Herein, we synthesized PF-graphene composites by the in situ polymerization of phenol and formaldehyde with the addition of graphene oxide, resulting in improved compatibility between the graphene and phenolic resin (PF) matrix and endowing the phenolic resin with good thermal stability and excellent tribological properties. Fourier-transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns demonstrated that the graphene oxide was reduced during the in-situ polymerization. The PF-graphene composites were sprayed onto steel blocks to form composite coatings. The effects of an applied load and of the sliding speed on the tribological properties of the PF-graphene composite coating were evaluated using a block-on-ring wear tester; in addition, the worn surface and the transfer film formed on the surface of the counterpart ring were studied by scanning electron microscopy (SEM). The results show that the PF-graphene composite coating exhibited enhanced tribological properties under all tested conditions.
Tribology in metal forming at elevated temperatures
Authors: Dohda Kuniaki , Boher Christine , Rezai-Aria Farhad , Mahayotsanun Numpon
Published: March 2015

The tribo-characteristics of metal forming at high temperatures have not yet been well understood due to the complex nature of thermal, microstructural, interaction, and process parameters. This is a review paper on the effects of temperature, coating, and lubrication to the tribological characteristics in hot forming as well as the tribometers for different metal forming processes at elevated temperatures mainly based on the experimental work. The tribological behaviors of oxides in hot forming, such as rolling and stamping, were reviewed and presented. Some commonly used surface coatings and lubricants in hot forming were given. Many types of tribometer were selected and presented and some of them provided a great potential to characterize friction and wear at elevated temperatures. Nevertheless, more testing conditions should be further investigated by developing new tribometers. Eventually, experimental results obtained from reliable tribometers could be used in theory and model developments for different forming processes and materials at high temperatures. The review also showed the great potential in further investigations and innovation in tribology.
Geological, hydrogeochemical, and microbiological characteristics of the Oil site of the Uzon caldera (Kamchatka)
Authors: Dobretsov N.L. , Lazareva E.V. , Zhmodik S.M. , Bryanskaya A.V. , Morozova V.V. , Tikunova N.V. , Peltek S.E. , Karpov G.A. , Taran O.P. , Ogorodnikova O.L. , Kirichenko I.S. , Rozanov A.S. , Babkin I.V. , Shuvaeva O.V. , Chebykin E.P.
Published: March 2015

This study used geological, geochemical, and microbiological data to examine the Uzon oils and conditions within the Uzon caldera. The trace-element compositions of crude oils and solutions from boreholes and hydrothermal springs were determined by ICP-MS. The majority of hydrothermal manifestations within the Uzon caldera are controlled by three trends of faults. The major fault zone, trending nearly E–W, is located between Kikhpinych and Taunshits volcanoes. It acts as a magma conduit and hosts numerous oval-shaped hydrothermal vents. The Oil site is situated on the periphery of the hottest area of highest hydrothermal activity within the Eastern thermal field. On the Eh–pH diagram, most solutions of the Uzon caldera define distinct fields and trends which correlate with the stability fields for sulfur and iron. The Oil site is characterized by very wide variations in temperature and Eh–pH parameters of pore solutions. The geochemical signatures of the solutions at this site are broadly similar to those from other areas of the Uzon caldera, but differ in their sulfide ion and sulfate ion concentrations. These differences can be explained by mixing of deep chloride-sodium hydrothermal solutions and solutions produced during surface oxidation of sulfide-containing material. With respect to the average continental crust, the Uzon oil is enriched in S, As, and Hg. The crude oil and solutions have broadly similar concentrations of B, S, Cl, As, Se, Br, Cd, I, Hg, and Pb and highly variable concentrations of Ti, V, Cr, Co, Ni, Cu, Cd, Nb, and Sn. The community structure of archaeal assemblages in springs and test pits at the Eastern thermal field was analyzed by 16S rRNA library and pyrosequencing methods. It was found that the proportion of archaea in the microbial communities of the Uzon caldera ranges from 2 to over 70% of the total sequences identified. Crenarchaeota were found in large proportions in all samples except one. The majority of the sequences in four samples were affiliated with Euryarchaeota, which comprise methanogenic archaea, extreme halophiles, and some extreme thermophiles. The results of geological, mineralogical-geochemical, microbiological and physicochemical studies of oil seeps in the Uzon caldera reveal distinctive geochemical characteristics of crude oil and the complexity of oil formation.
The role of rocks saturated with metallic iron in the formation of ferric carbonate–silicate melts: experimental modeling under PT-conditions of lithospheric mantle
Authors: Bataleva Yu.V. , Palyanov Yu.N. , Sokol A.G. , Borzdov Yu.M. , Bayukov O.A.
Published: March 2015

Experimental modeling of the processes of formation of ferric carbonate–silicate melts through the carbonate–oxide–metal interaction is performed in the (Mg,Ca)CO3–SiO2–Al2O3–Fe0 system at 6.3 and 7.5 GPa and within 1150-1650 °C, using a multianvil high-pressure apparatus of “split-sphere” type (BARS). Two parallel reactions run in the subsolidus region (1150-1450 °C): decarbonation, producing pyrope-almandine (Fe# = 0.40–0.75) and CO2 fluid, and redox interaction between carbonate and Fe0, resulting in the crystallization of iron carbide in assemblage with magnesiowustite (Fe# = 0.75–0.85). It is shown that the reduction of carbonate or CO2 fluid by iron carbide and parallel redox interaction of magnesiowustite with CO2 produce graphite in assemblage with Fe3+-containing magnesiowüstite. In the temperature range of 1450-1650 °C, generation of carbonate-silicate melts coexisting with pyrope-almandine, magnesiowustite, magnetite, ferrospinel, and graphite takes place. The composition of the produced melts is as follows: SiO2 = 10–15 wt.%, Ʃ(FeO + Fe2O3) = 36–43 wt.%, and Fe3+/ƩFe = 0.18–0.23. These Fe3+-enriched carbonate-silicate melts/fluids are saturated with carbon and are the medium of graphite crystallization. Oxide and silicate phases (almandine, ferrospinel, and magnetite) coexisting with graphite are also characterized by high Fe3+/ƩFe values. It has been established that Fe3+-enriched carbonate-silicate melts can result from the interaction of Fe0-containing rocks with carbonated rocks. In the reduced mantle (with the presence of iron carbides or oxides), melts of this composition can be the source of carbon and the medium of graphite crystallization at once. After separation and ascent, these ferric carbonate-silicate melts can favor oxidizing metasomatism in the lithospheric mantle.
Carbonatite metasomatism of peridotite lithospheric mantle: implications for diamond formation and carbonatite-kimberlite magmatism
Authors: Pokhilenko N.P. , Agashev A.M. , Litasov K.D. , Pokhilenko L.N.
Published: March 2015

Mineral inclusions in diamond record its origin at different depths, down to the lower mantle. However, most diamonds entrained with erupting kimberlite magma originate in lithospheric mantle. Lithospheric U-type diamonds crystallize during early metasomatism of reduced fO2 at the IW oxygen buffer) depleted peridotite in the roots of Precambrian cratons. Evidence of the metasomatic events comes from compositions of garnets in peridotitic xenoliths and inclusions in diamonds. On further interaction with carbonatitic melt, peridotite changes its composition, while diamond no longer forms in a more oxidized environment (fO2 near the CCO buffer). Silicate metasomatism of depleted peridotite (by basanite-like melts) does not induce diamond formation but may participate in generation of group I kimberlite. Low-degree (below 1%) partial melting of metasomatized peridotite produces a kimberlite-carbonatite magmatic assemblage, as in the case of the Snap Lake kimberlite dike. Occasionally, mantle metasomatism may occur as reduction reactions with carbonates and H2O giving rise to hydrocarbon compounds, though the origin of hydrocarbons in the deep mantle remains open to discussion. Melting experiments in carbonate systems show hydrous carbonated melts with low H2O to be the most plausible agents of mantle material transport. An experiment-based model implies melting of carbonates in subducting slabs within the mantle transition zone, leading to formation of carbonatitic diapirs, which can rise through the mantle by buoyancy according to the dissolution-precipitation mechanism. These processes, in turn, can form oxidized channels in the mantle and maintain diamond growth at the back of diapirs by reducing carbon from carbonated melts. When reaching the lithospheric base, such diapirs form a source of kimberlite and related magmas. The primary composition of kimberlite often approaches carbonatite with no more than 10–15% SiO2.
Evidence for phase transitions in mineral inclusions in superdeep diamonds of the São Luiz deposit (Brazil)
Authors: Zedgenizov D.A. , Shatsky V.S. , Panin A.V. , Evtushenko O.V. , Ragozin A.L. , Kagi H.
Published: March 2015

Evidence for phase transitions in mineral inclusions in superdeep diamonds of alluvial placers in the São Luiz River deposits (Brazil) is obtained by the electron backscatter diffraction technique. It has been shown that the crystal structure of superdeep diamonds is significantly deformed around inclusions of MgSi-, CaSi-, and CaTiSi-perovskites, SiO2 (stishovite?), and Mg2SiO4 (ringwoodite?). On the contrary, significant deformations around inclusions of olivine, ferropericlase, and majoritic garnet are not detected. The absence of deformation near these minerals reveals the lack of phase transitions with dramatic volume changes. The present study suggests that the formation of superdeep diamonds proceeds at different levels of the sublithospheric mantle, transition zone, and lower mantle.
A unique diamondiferous peridotite xenolith from the Udachnaya kimberlite pipe, Yakutia: role of subduction in diamond formation
Authors: Logvinova A.M. , Taylor L.A. , Fedorova E.N. , Yelisseyev A.P. , Wirth R. , Howarth G. , Reutsky V.N. , Sobolev N.V.
Published: March 2015

A unique xenolith of diamond-bearing pyrope peridotite has been studied, which consists of enstatite (Al2O3 = 0.39–0.43 wt.%; Cr2O3 = 0.20–0.23 wt.%; FeO = 4.81–5.1 wt.%; average Mg# = 92.7) and pyrope (Cr2O3 = 4.43–5.11 wt.%; CaO = 4.15–4.8 wt.%; Mg# = 83.6–84.1). The xenolith is small (10.5 g) but contains more than 30,000 diamond microcrystals (10–700 µm). High-resolution 2D and 3D X-ray tomographic images show the volume ratios of rock-forming minerals and an uneven distribution of diamonds in the xenolith (enstatite—38 vol.%; pyrope—35 vol.%; diamond—9.5 vol.%; sulfides—4 vol.%; and the remainder being mainly alteration products), with diamonds and sulfides being localized in the same zone. The sulfides are pentlandite and djerfisherite. Isotope and FTIR spectroscopic studies showed an extremely light carbon isotope composition (δ13Cav = –22.9%c) of the diamonds and minor nitrogen impurities (< 15 ppm) in them. Nitrogen is present mainly in aggregated form. The phase composition of nanoinclusions in the diamonds was investigated by transmission electron microscopy (TEM), including electron diffraction and analytical electron microscopy (AEM). It has been shown that all nanoinclusions are polyphase structures consisting of Mg–Al-silicate-enriched phases, Ca-carbonate, graphite, and fluid. The fluid phase has high concentrations of K, Cl, and O. The mineral inclusions in the diamonds are identified as high-Mg olivine. The data obtained indicate that the formation of diamonds in the studied xenolith was a one-act process and that the fluid/melt metasomatizing ultramafic substrate was of crustal origin. This testifies to the crucial role of deep metasomatic processes in the formation of the Udachnaya kimberlite pipe.
Multiple growth events in diamonds with cloudy microinclusions from the Mir kimberlite pipe: evidence from the systematics of optically active defects
Authors: Skuzovatov S.Yu. , Zedgenizov D.A. , Rakevich A.L. , Shatsky V.S. , Martynovich E.F.
Published: March 2015

We present new data on the main and additional optically active defects in diamonds with cloudy microinclusions from the Mir kimberlite pipe. It has been found that reshaping might have occurred either in a closed system with nitrogen and hydrogen depletion or owing to new portions of a diamond-forming fluid/melt. The internal structure and the distribution of optically active defects suggest both continuous growth of such diamonds and a multistage scenario with a series of postcrystallizational transformations, including resorption, high-temperature annealing, and degradation of nickel–nitrogen complexes.
FTIR mapping of diamond plates of eclogitic and peridotitic xenoliths from the Nyurbinskaya pipe, Yakutia: genetic implications
Authors: Spetsius Z.V. , Bogush I.N. , Kovalchuk O.E.
Published: March 2015

Results of studies of IR absorption and photo- and cathodoluminescence of diamonds from peridotitic and eclogitic xenoliths from the Nyurbinskaya pipe are presented. The internal structure of diamonds of different genesis and the changes in their impurity composition throughout the crystals are analyzed. A comparison is made for the spectral parameters of crystals from xenoliths of different genesis and from kimberlites of this pipe. The internal structure of 38 eclogitic and 4 peridotitic diamond (class –4 to +2 mm) crystals is examined on their 0.4–0.8 mm thick plane-parallel plates. We present results of a detailed study of diamonds with different characteristics from four eclogitic and two peridotitic xenoliths from the Nyurbinskaya pipe. Areal mapping of diamond plates from xenoliths showed varying contents of total nitrogen, its aggregates, and hydrogen and their zonal distribution in the investigated crystals. Peridotitic diamonds are characterized by low and medium nitrogen contents, a high degree of nitrogen aggregation, and low contents of hydrogen and seldom show signs of growth interruption. Eclogitic diamonds have high contents of nitrogen and hydrogen; there are many zoned diamonds with signs of multistage growth among them, which indicates that they are of several growth generations. The composition of inclusions, the distribution of nitrogen impurity, and the degree of nitrogen aggregation in diamonds testify to a predominance of eclogitic paragenesis crystals in the Nyurbinskaya pipe. The internal structure of eclogitic paragenesis crystals, the arrangement of diamonds in eclogitic xenoliths, and other facts argue for their later, compared with peridotitic xenolith diamonds, formation from fluid or fluid-melt during metasomatism. This determined the typomorphism of diamonds and high productivity of the pipe.
Virtual Reality Simulation Training for Ebola Deployment
Authors: Ragazzoni Luca , Ingrassia Pier Luigi , Echeverri Lina , Maccapani Fabio , Berryman Lizzy , Burkle Frederick M. , Della Corte Francesco
Published: March 2015

Both virtual and hybrid simulation training offer a realistic and effective educational framework and opportunity to provide virtual exposure to operational public health skills that are essential for infection control and Ebola treatment management. This training is designed to increase staff safety and create a safe and realistic environment where trainees can gain essential basic and advanced skills. (Disaster Med Public Health Preparedness. 2015;9:543–546
NO CROSS-CULTURAL DIFFERENCES IN THE GETTIER CAR CASE INTUITION: A REPLICATION STUDY OF WEINBERG ET AL. 2001
Authors: Kim Minsun , Yuan Yuan
Published: March 2015

In “Normativity and Epistemic Intuitions” (NEI), Weinberg, Nichols and Stich famously argue from empirical data that East Asians and Westerners have different intuitions about Gettier-style cases. We attempted to replicate their study about the Gettier Car Case. Our study used the same methods and case taken verbatim, but sampled an East Asian population 2.5 times greater than NEI's 23 participants. We found no evidence supporting the existence of cross-cultural difference about the intuition concerning the case. Taken together with the failures of both of the existing replication studies (Nagel et al. 2013; Seyedsayamdost 2014), our data provide strong evidence that the purported cross-cultural difference in intuitions about Gettier-style cases does not exist.
A Framework for HI Spectral Source Finding Using Distributed-Memory Supercomputing
Authors: Westerlund Stefan , Harris Christopher
Published: March 2015

The latest generation of radio astronomy interferometers will conduct all sky surveys with data products consisting of petabytes of spectral line data. Traditional approaches to identifying and parameterising the astrophysical sources within this data will not scale to datasets of this magnitude, since the performance of workstations will not keep up with the real-time generation of data. For this reason, it is necessary to employ high performance computing systems consisting of a large number of processors connected by a high-bandwidth network. In order to make use of such supercomputers substantial modifications must be made to serial source finding code. To ease the transition, this work presents the Scalable Source Finder Framework, a framework providing storage access, networking communication and data composition functionality, which can support a wide range of source finding algorithms provided they can be applied to subsets of the entire image. Additionally, the Parallel Gaussian Source Finder was implemented using SSoFF, utilising Gaussian filters, thresholding, and local statistics. PGSF was able to search on a 256GB simulated dataset in under 24 minutes, significantly less than the 8 to 12 hour observation that would generate such a dataset.
Understanding socio-economic inequalities in food choice behaviour: can Maslow's pyramid help?
Authors: van Lenthe Frank J. , Jansen Tessa , Kamphuis Carlijn B. M.
Published: March 2015

Socio-economic groups differ in their material, living, working and social circumstances, which may result in different priorities about their daily-life needs, including the priority to make healthy food choices. Following Maslow's hierarchy of human needs, we hypothesised that socio-economic inequalities in healthy food choices can be explained by differences in the levels of need fulfilment. Postal survey data collected in 2011 (67·2 % response) from 2903 participants aged 20–75 years in the Dutch GLOBE (Gezondheid en Levens Omstandigheden Bevolking Eindhoven en omstreken) study were analysed. Maslow's hierarchy of human needs (measured with the Basic Need Satisfaction Inventory) was added to age- and sex-adjusted linear regression models that linked education and net household income levels to healthy food choices (measured by a FFQ). Most participants (38·6 %) were in the self-actualisation layer of the pyramid. This proportion was highest among the highest education group (47·6 %). Being in a higher level of the hierarchy was associated with a higher consumption of fruits and vegetables as well as more healthy than unhealthy bread, snack and dairy consumption. Educational inequalities in fruit and vegetable intake (B= − 1·79, 95 % CI − 2·31, − 1·28 in the lowest education group) were most reduced after the hierarchy of needs score was included (B= − 1·57, 95 % CI − 2·09, − 1·05). Inequalities in other healthy food choices hardly changed after the hierarchy of needs score was included. People who are satisfied with higher-level needs make healthier food choices. Studies aimed at understanding socio-economic inequalities in food choice behaviour need to take differences in the priority given to daily-life needs by different socio-economic groups into account, but Maslow's pyramid offers little help.
Anthropometric, lifestyle and parental characteristics associated with the prevalence of energy intake misreporting in children: the GRECO (Greek Childhood Obesity) study
Authors: Farajian Paul , Bountziouka Vassiliki , Risvas Grigoris , Panagiotakos Demosthenes B. , Zampelas Antonis
Published: March 2015

The objectives of the present study were to identify childhood energy misreporting, and evaluate characteristics that are associated with its prevalence in a nationwide cross-sectional sample of Greek schoolchildren. Under the context of the GRECO (Greek Childhood Obesity) study, data from a total of 4547 children aged 10–12 years and 2318 parents were included in the analysis. Anthropometric, lifestyle and parental characteristics plus psychological concerns were investigated in relation to the prevalence of energy misreporting. Of the included children, 36 % were classified as energy under-reporters and 16 % as over-reporters. Multinomial logistic regression analysis revealed that the most important predictors of energy under-reporting (URP) were children's BMI (OR 1·11, 95 % CI 1·09, 1·14) and weight satisfaction (OR 0·87, 95 % CI 0·78, 0·97). In the case of energy over-reporting (ORP), children's BMI (OR 0·87, 95 % CI 0·84, 0·90), meal and snack consumption frequency (OR 1·52, 95 % CI 1·32, 1·75), female sex (OR 0·65, 95 % CI 0·45, 0·90), and maternal education (OR 0·95, 95 % CI 0·91, 0·99) remained as significant predictors. Additionally, parental perception that the body weight of their children was normal reduced the odds of URP (OR 0·69, 95 % CI 0·48, 0·99) and ORP (OR 0·53, 95 % CI 0·31, 0·93). In conclusion, the present study confirms that the issue of URP and ORP in childhood populations is evident and quite serious. Although there are no definite guidelines on how to use data obtained from misreporters in an epidemiological dataset, validity of reported energy intake seems to be influenced by children's BMI and weight satisfaction, as well as by parental perceptions regarding their children's weight.