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https://www.readbyqxmd.com/read/28222134/gis-based-landform-classification-of-bronze-age-archaeological-sites-on-crete-island
#1
Athanasios V Argyriou, Richard M Teeuw, Apostolos Sarris
Various physical attributes of the Earth's surface are factors that influence local topography and indirectly influence human behaviour in terms of habitation locations. The determination of geomorphological setting plays an important role in archaeological landscape research. Several landform types can be distinguished by characteristic geomorphic attributes that portray the landscape surrounding a settlement and influence its ability to sustain a population. Geomorphometric landform information, derived from digital elevation models (DEMs), such as the ASTER Global DEM, can provide useful insights into the processes shaping landscapes...
2017: PloS One
https://www.readbyqxmd.com/read/28221387/one-step-in-situ-synthesis-of-core-shell-structured-cr2o3-p-fibrous-phosphorus-hybrid-composites-with-highly-efficient-full-spectrum-response-photocatalytic-activities
#2
Hongpeng Zhou, Shixin Xu, Dingke Zhang, Shijian Chen, Junkai Deng
Making full use of solar energy and achieving high charge separation efficiency are critical factors for the photocatalysis technique. In this work, we report core-shell structured fibrous phosphorus (f-P) coated P-doped Cr2O3 (Cr2O3:P@f-P) hybrid composites with a strong optical absorption in the full region of 200-2600 nm. The Cr2O3:P@f-P hybrid composites exhibit a record photocatalytic efficiency under UV, visible and near-infrared light irradiation, demonstrating as promising photocatalysts for the full utilization of solar energy...
February 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28221348/self-assembly-of-nanoparticles-into-biomimetic-capsid-like-nanoshells
#3
Ming Yang, Henry Chan, Gongpu Zhao, Joong Hwan Bahng, Peijun Zhang, Petr Král, Nicholas A Kotov
Nanoscale compartments are one of the foundational elements of living systems. Capsids, carboxysomes, exosomes, vacuoles and other nanoshells easily self-assemble from biomolecules such as lipids or proteins, but not from inorganic nanomaterials because of difficulties with the replication of spherical tiling. Here we show that stabilizer-free polydispersed inorganic nanoparticles (NPs) can spontaneously organize into porous nanoshells. The association of water-soluble CdS NPs into self-limited spherical capsules is the result of scale-modified electrostatic, dispersion and other colloidal forces...
March 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28221039/polycyclic-aromatic-hydrocarbons-via-iron-iii-catalyzed-carbonyl-olefin-metathesis
#4
Christopher C McAtee, Paul S Riehl, Corinna S Schindler
Polycyclic aromatic hydrocarbons are important structural motifs in organic chemistry, pharmaceutical chemistry, and materials science. The development of a new synthetic strategy toward these compounds is described based on the design principle of iron(III)-catalyzed carbonyl-olefin metathesis reactions. This approach is characterized by its operational simplicity, high functional group compatibility, and regioselectivity while relying on FeCl3 as an environmentally benign, earth-abundant metal catalyst. Experimental evidence for oxetanes as reactive intermediates in the catalytic carbonyl-olefin ring-closing metathesis has been obtained...
February 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28220886/earth-s-oldest-bobbit-worm-gigantism-in-a-devonian-eunicidan-polychaete
#5
Mats E Eriksson, Luke A Parry, David M Rudkin
Whilst the fossil record of polychaete worms extends to the early Cambrian, much data on this group derive from microfossils known as scolecodonts. These are sclerotized jaw elements, which generally range from 0.1-2 mm in size, and which, in contrast to the soft-body anatomy, have good preservation potential and a continuous fossil record. Here we describe a new eunicidan polychaete, Websteroprion armstrongi gen. et sp. nov., based primarily on monospecific bedding plane assemblages from the Lower-Middle Devonian Kwataboahegan Formation of Ontario, Canada...
February 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28220809/multicolor-light-emitting-devices-with-tb2o3-on-silicon
#6
Ling Li, Shenwei Wang, Guangyao Mu, Xue Yin, Lixin Yi
Great efforts have been devoted to achieving efficient Si-based light-emitting devices. Here we report new light-emitting devices fabricated with Tb2O3 on Si substrates. Intense green electroluminescence was observed, with a turn-on voltage of about 8 V. The green emission is attributed to the characteristic transitions of Tb(3+) ions in Tb2O3. The electroluminescence mechanisms of the Tb2O3 light-emitting devices are discussed. In addition, visible and near infrared electroluminescence was observed in rare-earth (Eu(3+), Sm(3+) and Yb(3+)) doped Tb2O3 light-emitting devices...
February 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28220787/understanding-the-glacial-methane-cycle
#7
Peter O Hopcroft, Paul J Valdes, Fiona M O'Connor, Jed O Kaplan, David J Beerling
Atmospheric methane (CH4) varied with climate during the Quaternary, rising from a concentration of 375 p.p.b.v. during the last glacial maximum (LGM) 21,000 years ago, to 680 p.p.b.v. at the beginning of the industrial revolution. However, the causes of this increase remain unclear; proposed hypotheses rely on fluctuations in either the magnitude of CH4 sources or CH4 atmospheric lifetime, or both. Here we use an Earth System model to provide a comprehensive assessment of these competing hypotheses, including estimates of uncertainty...
February 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28220784/origin-of-heavy-rare-earth-mineralization-in-south-china
#8
Cheng Xu, Jindřich Kynický, Martin P Smith, Antonin Kopriva, Martin Brtnický, Tomas Urubek, Yueheng Yang, Zheng Zhao, Chen He, Wenlei Song
Heavy rare earth elements (HREE) are dominantly mined from the weathering crusts of granites in South China. Although weathering processes occur globally, no economic HREE resources of this type have yet been found outside China. Here, we report the occurrence of unidentified REE minerals in the granites from South Chinese deposits. They contain high levels of both HREE and light REE, but are strongly depleted in Ce, implying high oxidation state. These REE minerals show higher initial Nd isotope than primary REE-rich minerals (ɛNd(t)=0...
February 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28220680/an-environmental-sociology-for-the-anthropocene
#9
Gary Bowden
Attention to the relationship between nature and society has been a defining feature of environmental sociology since its inception. Early research, incorporating insights from ecology, argued for the need to (1) theorize the causal connections between nature and society and (2) contextualize those connections in terms of biophysical limits resulting from resource scarcity. Over the past two decades, partly in response to new forms of existential threat such as climate change, the treatment of nature and society as distinct entities has given way to a focus on socio-natural assemblages...
February 2017: Canadian Review of Sociology, Revue Canadienne de Sociologie
https://www.readbyqxmd.com/read/28220677/toward-a-sociology-of-oceans
#10
John Hannigan
Despite covering around 70 percent of the earth's surface, the ocean has long been ignored by sociology or treated as merely an extension of land-based systems. Increasingly, however, oceans are assuming a higher profile, emerging both as a new resource frontier, a medium for geopolitical rivalry and conflict, and a unique and threatened ecological hot spot. In this article, I propose a new sociological specialty area, the "sociology of oceans" to be situated at the interface between environmental sociology and traditional maritime studies...
February 2017: Canadian Review of Sociology, Revue Canadienne de Sociologie
https://www.readbyqxmd.com/read/28218831/new-possibilities-for-magnetic-control-of-chemical-and-biochemical-reactions
#11
Anatoly Buchachenko, Ronald G Lawler
Chemistry is controlled by Coulomb energy; magnetic energy is lower by many orders of magnitude and may be confidently ignored in the energy balance of chemical reactions. The situation becomes less clear, however, when reaction rates are considered. In this case, magnetic perturbations of nearly degenerate energy surface crossings may produce observable, and sometimes even dramatic, effects on reactions rates, product yields, and spectroscopic transitions. A case in point that has been studied for nearly five decades is electron spin-selective chemistry via the intermediacy of radical pairs...
February 20, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28218806/novel-bimorphological-anisotropic-bulk-nanocomposite-materials-with-high-energy-products
#12
Xiaohong Li, Li Lou, Wenpeng Song, Guangwei Huang, Fuchen Hou, Qian Zhang, Hai-Tian Zhang, Jianwei Xiao, Bin Wen, Xiangyi Zhang
Nanostructuring of magnetically hard and soft materials is fascinating for exploring next-generation ultrastrong permanent magnets with less expensive rare-earth elements. However, the resulting hard/soft nanocomposites often exhibit random crystallographic orientations and monomorphological equiaxed grains, leading to inferior magnetic performances compared to corresponding pure rare-earth magnets. This study describes the first fabrication of a novel bimorphological anisotropic bulk nanocomposite using a multistep deformation approach, which consists of oriented hard-phase SmCo rod-shaped grains and soft-phase Fe(Co) equiaxed grains with a high fraction (≈28 wt%) and small size (≈10 nm)...
February 20, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28218409/development-of-haemostatic-decontaminants-for-treatment-of-wounds-contaminated-with-chemical-warfare-agents-3-evaluation-of-in-vitro-topical-decontamination-efficacy-using-damaged-skin
#13
Helen L Lydon, Charlotte A Hall, Christopher H Dalton, J Kevin Chipman, John S Graham, Robert P Chilcott
Previous studies have demonstrated that haemostatic products with an absorptive mechanism of action retain their clotting efficiency in the presence of toxic materials and are effective in decontaminating chemical warfare (CW) agents when applied to normal, intact skin. The purpose of this in vitro study was to assess three candidate haemostatic products for effectiveness in the decontamination of superficially damaged porcine skin exposed to the radiolabelled CW agents, soman (GD), VX and sulphur mustard (HD)...
February 20, 2017: Journal of Applied Toxicology: JAT
https://www.readbyqxmd.com/read/28218405/electricity-generation-by-pyrococcus-furiosus-in-microbial-fuel-cells-operated-at-90-%C3%A2-c
#14
Narendran Sekar, Chang-Hao Wu, Michael W W Adams, Ramaraja P Ramasamy
Hyperthermophiles are microorganisms that thrive in extremely hot environments with temperatures near and even above 100 (°) C. They are the most deeply rooted microorganisms on phylogenetic trees suggesting they may have evolved to survive in the early hostile earth. The simple respiratory systems of some of these hyperthermophiles made them potential candidates to develop microbial fuel cells (MFC) that can generate power at temperatures approaching the boiling point. We explored extracellular electron transfer ability of a hyperthermophilic archaeon Pyrococcus furiosus (Pf) by studying its ability to generate electricity in a two-chamber MFC...
February 20, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28217899/indirect-ultraviolet-detection-of-alkaline-earth-metal-ions-using-an-imidazolium-ionic-liquid-as-an-ultraviolet-absorption-reagent-in-ion-chromatography
#15
Yong-Qiang Liu, Hong Yu
A convenient and versatile method was developed for the separation and detection of alkaline earth metal ions by ion chromatography with indirect ultraviolet detection. The chromatographic separation of Mg(2+) , Ca(2+) and Sr(2+) was performed on a carboxylic acid base cation exchange column using imidazolium ionic liquid/acid as the mobile phase, in which the imidazolium ionic liquid acted as an ultraviolet-absorption reagent. The effects of imidazolium ionic liquids, detection wavelength, acids in the mobile phase and column temperature on the retention of Mg(2+) , Ca(2+) and Sr(2+) were investigated...
February 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28217063/ultrasound-guided-probe-generated-artifacts-stimulating-ventricular-tachycardia-a-rare-phenomenon
#16
Rafat Shamim, Rudrashish Haldar, Ashutosh Kaushal
Electrocardiographic (ECG) artifacts may arise due to interference, faulty earthing, and current leakages in biomedical equipment which might create clinical dilemmas in the perioperative settings. Piezoelectric signals generated by ultrasonography probe are another uncommon source which might be sensed by the ECG electrodes and produce tracings similar to pathological arrhythmias triggering false alarms and avoidable therapies. Anesthesiologists should be familiar with these uncommon sources which might produce these artifacts and they should be identified swiftly...
January 2017: Saudi Journal of Anaesthesia
https://www.readbyqxmd.com/read/28217039/desiccant-dust-and-the-use-of-co2-gas-as-a-mobility-stimulant-for-bed-bugs-a-potential-control-solution
#17
Anders Aak, Espen Roligheten, Bjørn Arne Rukke, Tone Birkemoe
The common bed bug (Cimex lectularius, Hemiptera; Cimicidae) infests homes and service industries, and the number of infestations has greatly increased over the past 20 years. At present, no cost-effective control methods are available, and eradication programs are expensive and laborious. We investigated the control potential of desiccant dust in combination with CO2 as a bed bug activity stimulant. An initial experiment with two desiccant dusts was followed by arena studies with varying doses, available hiding places and the presence or absence of host signals...
2017: Journal of Pest Science
https://www.readbyqxmd.com/read/28216664/iron-isotopic-fractionation-between-silicate-mantle-and-metallic-core-at-high-pressure
#18
Jin Liu, Nicolas Dauphas, Mathieu Roskosz, Michael Y Hu, Hong Yang, Wenli Bi, Jiyong Zhao, Esen E Alp, Justin Y Hu, Jung-Fu Lin
The +0.1‰ elevated (56)Fe/(54)Fe ratio of terrestrial basalts relative to chondrites was proposed to be a fingerprint of core-mantle segregation. However, the extent of iron isotopic fractionation between molten metal and silicate under high pressure-temperature conditions is poorly known. Here we show that iron forms chemical bonds of similar strengths in basaltic glasses and iron-rich alloys, even at high pressure. From the measured mean force constants of iron bonds, we calculate an equilibrium iron isotope fractionation between silicate and iron under core formation conditions in Earth of ∼0-0...
February 20, 2017: Nature Communications
https://www.readbyqxmd.com/read/28215329/biotechnological-applications-of-marine-enzymes-from-algae-bacteria-fungi-and-sponges
#19
S Parte, V L Sirisha, J S D'Souza
Diversity is the hallmark of all life forms that inhabit the soil, air, water, and land. All these habitats pose their unique inherent challenges so as to breed the "fittest" creatures. Similarly, the biodiversity from the marine ecosystem has evolved unique properties due to challenging environment. These challenges include permafrost regions to hydrothermal vents, oceanic trenches to abyssal plains, fluctuating saline conditions, pH, temperature, light, atmospheric pressure, and the availability of nutrients...
2017: Advances in Food and Nutrition Research
https://www.readbyqxmd.com/read/28214629/effects-of-metal-ion-replacement-on-pyrazinamidase-activity-a-quantum-mechanical-study
#20
Mahmoud Khadem-Maaref, Faramarz Mehrnejad, Arash Phirouznia
Pyrazinamidase (PZase), a metalloenzyme, is responsible for acidic modification of pyrazinamide (PZA), a drug used in tuberculosis treatment. The metal coordination site of the enzyme is able to coordinate various divalent metal cofactors. Previous experimental studies have demonstrated that metal ions, such as Co(2+), Mn(2+), and Zn(2+), are able to reactivate metal-depleted PZase, while others including Cu(2+), Fe(2+), and Mg(2+), cannot restore activity. In this study, we investigated binding of various metal ions to the metal coordination site (MCS) of the enzyme using quantum mechanical calculations...
February 2, 2017: Journal of Molecular Graphics & Modelling
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