bluuebunny/crossref_metadata_2025 huggingface dataset:
A Self‐Assembled Luminescent Host That Selectively Senses ATP in Water
Authors: Ahmad Haslina , Hazel Benedict W. , Meijer Anthony J. H. M. , Thomas Jim A. , Wilkinson Karl A.
Published: February 2013

Metal‐ion‐directed self‐assembly has been used to construct kinetically inert, water‐soluble heterometallic Ru2Re2 hosts that are potential sensors for bioanions. A previously reported metallomacrocycle and a new derivative synthesised by this approach are found to be general sensors for bioanions in water, showing an “off–on” luminescent change that is selective for nucleotides over uncharged nucleobases. Through a change in the ancillary ligands coordinated to the ruthenium centres of the host, an “off–on” sensor has been produced. Whilst this host only shows a modest enhancement in binding affinities for nucleotides relative to the other two host systems, its sensing response is much more specific. Although a distinctive “off–on” luminescence response is observed for the addition of adenosine triphosphosphate (ATP), related structures such as adenine and guanosine triphosphate (GTP) do not induce any emission change in the host. Detailed and demanding DFT studies on the ATP‐ and GTP‐bound host–guest complexes reveal subtle differences in their geometries that modulate the stacking interactions between the nucleotide guests and the ancillary ligands of the host. It is suggested that this change in stacking geometries affects solvent accessibility to the binding pocket of the host and thus leads to observed difference in the host luminescence response to the guests.
ChemInform Abstract: Theoretical Study of Nitrogen‐Rich CN3‐ Anion and Related Salts M+[CN3]‐ (M: Li, Na, K).
Authors: Gao Si‐meng , Ding Yi‐hong
Published: February 2013

Structures and stabilities of CN3‐ are computed at various levels of theory.
ChemInform Abstract: Bismuth Iridium Oxide Oxygen Evolution Catalyst from Hydrothermal Synthesis.
Authors: Walton Richard I. , et al. et al.
Published: February 2013

Bi2Ir2O7 is hydrothermally synthesized from an aqueous NaOH solution of NaBiO3 and IrCl3 in the presence of Na2O2 (autoclave, 240 °C, 120 h).
ChemInform Abstract: A New General Synthetic Strategy for Phase‐Pure Complex Functional Materials.
Authors: Green David C. , Glatzel Stefan , Collins Andrew M. , Patil Avinash J. , Hall Simon R.
Published: February 2013

Functional oxides such as YBa2Cu3O7‐x, Bi2Sr2CaCu2O8, Na0.5K0.5NbO3, BiFeO3:Y, PrCoO3:Ni, and Y3Al5O12:Tb are synthesized by a new phase‐transfer protocol involving the addition of [emim]OAc or [emim]NO3 to an aqueous system containing stoichiometric ratios of metal ions which is then heated (80 °C, 2—3 h) to dehydrate the solution, followed by dissolution of microcrystalline cellulose up to 10 wt.%.
ChemInform Abstract: One Novel 3‐D Vanadoborate with Unusual 3‐D Na—O—Na Network.
Authors: Zhou Jian , Liu Xing , Hu Feilong , Zou Huahong , Li Rong , Li Xiaojuan
Published: February 2013

The new compound {Na2B18V12O54(OH)6 (H2O)[Na8(H2O)16]}·2 H2O is hydrothermally synthesized from a mixture of NH4VO3, Na2SO3, H3BO3, diaminopropane, and water (autoclave, pH 8.5, 110 °C, 7 d, 73% yield).
ChemInform Abstract: Lactone Radical Cyclizations and Cyclization Cascades Mediated by SmI2—H2O.
Authors: Parmar Dixit , Matsubara Hiroshi , Price Kieran , Spain Malcolm , Procter David J.
Published: February 2013

Full studies on the formation of oxygenated cycloheptanes by reductive cyclization of alkenyl‐ and alkynyllactones are reported.
ChemInform Abstract: Reductive Hydroxyalkylation/Alkylation of Amines with Lactones/Esters.
Authors: Wang Yu‐Huang , Ye Jian‐Liang , Wang Ai‐E , Huang Pei‐Qiang
Published: February 2013

In contrast to Weinreb amides, the reduction of in situ prepared Weinreb amides with DIBAL leads to amines, e.g. (Vb).
ChemInform Abstract: Selective Rhodium(III)‐Catalyzed Cross‐Dehydrogenative Coupling of Furan and Thiophene Derivatives.
Authors: Kuhl Nadine , Hopkinson Matthew N. , Glorius Frank
Published: February 2013

A novel rhodium(III)‐catalyzed cross‐dehydrogenative coupling of various furan and thiophene derivatives leads to valuable bi(heteroaryl) products in good yields and selectivities.
ChemInform Abstract: Efficient Preparation of 1,3‐Diol Derivatives with Three Contiguous Stereocenters by an Enantioselective Direct Aldol—Tishchenko Reaction.
Authors: Ichibakase Tomonori , Nakajima Makoto
Published: February 2013

Benzaldehyde is found to be optimal for the process which gives 1,3‐diols with three contiguous stereocenters in good enantioselectivity.
ChemInform Abstract: Catalytic Application of Dinuclear Palladium(II) Bis(thiosemicarbazone) Complex in the Mizoroki—Heck Reaction.
Authors: Prabhu Rupesh Narayana , Ramesh Rengan
Published: February 2013

Excellent yields are obtained within a short time in the presence of low catalyst loading if aryl bromides are used in the process.
ChemInform Abstract: Ephedrine‐Based Diselenide: A Promiscuous Catalyst Suitable to Mimic the Enzyme Glutathione Peroxidase (GPx) and to Promote Enantioselective C—C Coupling Reactions.
Authors: Soares Letiere C. , Alberto Eduardo E. , Schwab Ricardo S. , Taube Paulo S. , Nascimento Vanessa , Rodrigues Oscar E. D. , Braga Antonio L.
Published: February 2013

The applied catalyst is prepared from (‐)‐ephedrine in only one step in good yields.
ChemInform Abstract: A Facile Method for the Synthesis of 3‐Substituted 3‐(Alkylthio)oxindoles or 3‐Alkoxyoxindoles.
Authors: Zhu Feng , Zhou Feng , Cao Zhong‐Yan , Wang Chao , Zhang Yong‐Xue , Wang Cui‐Hong , Zhou Jian
Published: February 2013

A systematic study is presented for the reaction of 3‐hydroxyindoles with thiols and alcohols in the presence of perchloric acid.
ChemInform Abstract: Synthesis of Pyrrolo[2,3‐b]indole via Iodine(III)‐Mediated Intramolecular Annulation.
Authors: Tu Dandan , Ma Liying , Tong Xiaogang , Deng Xu , Xia Chengfeng
Published: February 2013

The procedure is highly suitable for the preparation of various alkaloid substructures.
ChemInform Abstract: Diastereoselective Additions of Titanium Enolates from N‐Glycolyl Thiazolidinethiones to Acetals.
Authors: Baiget Jessica , Caba Marta , Galvez Erik , Romea Pedro , Urpi Felix , Font‐Bardia Merce
Published: February 2013

The stereoselective outcome of the title reaction is found to depend on the nature of the O‐protecting group of glycolate substrate.
ChemInform Abstract: A Novel and Efficient One‐Pot Synthesis of 2,4‐Disubstituted Thiazoles and Oxazoles Using Phenyltrimethylammoniumtribromide in Ionic Liquid.
Authors: Muthyala Manoj Kumar , Kumar Anil
Published: February 2013

Title compounds (III) and (V), resp., are efficiently synthesized from ketones (I) using phenyltrimethylammonium tribromide as in situ brominating agent.
ChemInform Abstract: Pd/Cu‐Catalyzed C—H Arylation of 1,3,4‐Thiadiazoles with (Hetero)aryl Iodides, Bromides, and Triflates.
Authors: Vachhani Dipak D. , Sharma Abhishek , Van der Eycken Erik
Published: February 2013

A new direct arylation of thiadiazoles yielding a number of 2,5‐diarylated derivatives is reported.
ChemInform Abstract: Isomeric 3‐Isoxadiazolylcoumarins and Their Derivatives.
Authors: Detistov Oleksandr S. , Orlov Valeriy D. , Zhuravel Irina O.
Published: February 2013

3‐[1,2,4‐Oxadiazol‐5‐yl]coumarins (III) and (VII) are synthesized by condensation reaction of coumarin‐3‐carboxylic acids (I) and amidoximes (II) or by interaction of cyanomethyloxadiazoles (V) with salicylic aldehydes, respectively.
ChemInform Abstract: Simple and Practical Synthesis of Pyrano‐ and Furano[3,2‐c]quinoline Derivatives under Non‐Lewis Acid Catalysis.
Authors: Liu Rui Huan , Yu Xin , Hu Liang , Yu Nie Fang
Published: February 2013

The HCl‐catalyzed Povarov reaction of anilines, aldehydes, and oxygen heterocycles (III) or (VIII) produces the title compounds as a mixture of diastereomers.
ChemInform Abstract: 2‐Acyl(aroyl)‐1,1,3,3‐tetracyanopropenides. Part 4. Synthesis of 1‐Alkyl(aryl)‐4‐amino‐6‐iodo‐3‐oxo‐1,3‐dihydrofuro [3,4‐c]pyridine‐7‐carbonitriles.
Authors: Kayukov Ya. S. , Karpov S. V. , Bardasov I. N. , Kayukova O. V. , Ershov O. V. , Nasakin O. E.
Published: February 2013

The addition of hydrogen iodide occurs regioselectively to the cyano groups of the dicyanomethylene fragment of tetracyanopropenides (I).
ChemInform Abstract: Microwave‐Assisted Solvent‐Free Synthesis of Highly Functionalized Pyrimidine Derivatives.
Authors: Yan Shengjiao , Niu Yanfei , Chen Xuebing , Liu Yongjiang , Lin Jun
Published: February 2013

An efficient and environmentally friendly procedure for the synthesis of highly functionalized pyrimidines via microwave‐assisted reactions of ketene dithioacetals with guanidine (II) or amidine (XII) is given.
ChemInform Abstract: A Re‐Examination of the Reaction of 3,4‐Diamino[1,2,5]oxadiazole with Glyoxal.
Authors: Willer Rodney L. , Storey Robson F. , Campbell Christopher G. , Bunte Steven W. , Parrish Damon
Published: February 2013

Reaction diaminooxadiazole (I) with glyoxal under slightly basic conditions affords the expected dihydroxytetrahydrooxadiazolypyrazine (III).
ChemInform Abstract: Synthesis and Functionalization of 8‐Methyl‐2H‐pyrimido[2,1‐c][1,2,4]triazine‐3,6(1H,4H)‐dione.
Authors: Jakubkiene Virginija , Cepla Vytautas , Burbuliene Milda M. , Vainilavicius Povilas
Published: February 2013

The title compound (II) is obtained by an intramolecular cyclization reaction of acetohydrazide (I).
ChemInform Abstract: Conversion of Some 2(3H)‐Furanones into Pyrrolinotriazine and Oxazolopyrimidine Derivatives.
Authors: Abou‐Elmagd Wael S. I. , Hashem Ahmed I.
Published: February 2013

Furanones (I) are converted to triazine (IV) or, via hydrazide (V), to oxazolopyrimidines (X).
ChemInform Abstract: One‐Pot Synthesis of Macrocyclic Tetralactones via the Sequential Inter‐ and Intramolecular [2 + 2] Photocycloaddition Reaction of Di‐2‐pyrones with Polyethylene Glycol Dimethacrylates.
Authors: Shimo Tetsuro , Matsukubo Hideki , Zhang Hui Min
Published: February 2013

Photocycloaddition between polyethylene glycol‐di‐2‐pyrones and polyethylene glycol dimethacrylates such as (I) and (II) yields macrocyclic crown ether‐type compounds by [2 + 2] addition of the C5‐C6 and C5‐C6double bonds of (I) to the two olefin moieties of (II), generating 19‐ to31‐membered rings.
ChemInform Abstract: Competitive Condensation and Tandem Cyclization Reactions of 2‐Cyano‐3‐ferrocenylacrylonitrile with Amidines in an Aqueous Medium.
Authors: Klimova Elena I. , Flores‐Alamo Marcos , Mendez Stivalet Jose M. , Klimova Tatiana
Published: February 2013

The aim of this work is the synthesis of aminocyano(ferrocenyl)pyrimidine and pyridine derivatives by reactions of cyanoferrocenylacrylonitrile (I) with amidines (II).
ChemInform Abstract: Thermochromic Thin Films and Nanocomposites for Smart Glazing
Authors: Binions Russell
Published: February 2013

Review: 136 refs.
ChemInform Abstract: Metal Complexes of Diaryl and 2,2′‐Dipyridyl Disulfides
Authors: Moosun S. , Laulloo S. J. , Bhowon M. G.
Published: February 2013

Review: 108 refs.
ChemInform Abstract: Overcoming the Limitations of Lithiation Chemistry for Organoboron Compounds with Continuous Processing
Authors: Desai Aman A.
Published: February 2013

Review: 22 refs.
ChemInform Abstract: Advances in the Catalytic Production of Valuable Levulinic Acid Derivatives
Authors: Zhang Jun , Wu ShuBin , Li Bo , Zhang HongDan
Published: February 2013

Review: 84 refs.
ChemInform Abstract: Enzymatic Synthesis of Sugar Fatty Acid Esters in Ionic Liquids
Authors: Yang Zhen , Huang Ze‐Lin
Published: February 2013

Review: 40 refs.
ChemInform Abstract: Cinchona‐Based Primary Amine Catalysis in the Asymmetric Functionalization of Carbonyl Compounds
Authors: Melchiorre Paolo
Published: February 2013

Review: ca. 200 refs.
ChemInform Abstract: Review of Pt‐Based Bimetallic Catalysis: From Model Surfaces to Supported Catalysts
Authors: Yu Weiting , Porosoff Marc D. , Chen Jingguang G.
Published: February 2013

Review: 423 refs.
ChemInform Abstract: Gold‐Catalyzed Direct Arylation
Authors: Ball Liam T. , Lloyd‐Jones Guy C. , Russell Christopher A.
Published: February 2013

Review: 43 refs.
ChemInform Abstract: Graphene‐Based Electrodes
Authors: Huang Xiao , Zeng Zhiyuan , Fan Zhanxi , Liu Juqing , Zhang Hua
Published: February 2013

Review: 384 refs.
ChemInform Abstract: Reflections on the Chemistry of the Fischer—Tropsch Synthesis
Authors: James Olusola O. , Chowdhury Biswajit , Mesubi M. Adediran , Maity Sudip
Published: February 2013

Review: 166 refs.
ChemInform Abstract: Solid‐State NMR Applied to Photosynthetic Light‐Harvesting Complexes
Authors: Pandit Anjali , Groot Huub J. M.
Published: February 2013

Review: 43 refs.
Theoretical Study on the Photodegradation Mechanism of Nona‐BDEs in Methanol
Authors: Pan Lu , Bian Wensheng
Published: February 2013

Polybrominated diphenyl ethers (PBDEs) have received special environmental concern due to their potential toxicity to humans and wildlife worldwide, however, it is difficult to reveal their dominant photochemical degradation pathways by experiment. We explored the reaction mechanisms of photochemical degradation–debromination of three nona‐BDEs in methanol using theoretical calculations, in which time‐dependent density functional theory (TDDFT) combined with the polarizable continuum (PCM) model is applied. The selectivity of debromination was studied, and the major octa‐BDE products photochemically debrominated from nona‐BDEs were identified. We find that the debromination reaction results from the electronic transitions from π to σ* orbitals when nona‐BDEs are exposed to UV‐light in the sunlight region, at which point the two low‐lying excited states for each nona‐BDE are πσ*(5Br) and πσ*(4Br), which correlate to the σ* orbitals located on the penta‐Br and tetra‐Br substituted phenyls, respectively. Our calculations indicate that each nona‐BDE may degrade to form three kinds of octa‐BDE products via the πσ*(5Br) state, whereas only one kind of octa‐BDEs can be formed via the πσ*(4Br) state. Our calculations can interpret the recent experiments successfully.
Accurate estimation of Doppler shift in mobile communications with high vehicle speed
Authors: Hua J.Y. , Yuan D.H. , Li G. , Meng L.M.
Published: February 2013

Representing the channel varying rate and the mobile speed of a mobile terminal directly, Doppler shift is an important parameter in vehicular mobile communications and therefore is widely used in mobile target detection and adaptive applications. Hence, this paper puts forward an accurate Doppler shift estimator in mobile communications with high vehicle speeds, which can also be treated as a vehicular speed estimator due to the well‐known relation between the Doppler shift and the mobile speed. Specifically, the proposed estimator is based on the channel level crossing rate, and an iterative process is presented to achieve signal‐to‐noise ratio (SNR) insensitive estimates in accordance with the level crossing rate estimation error analysis. Moreover, we prove the convergency of the iterative Doppler shift estimator in theory. Computer simulations conducted under a wide range of noise corruption clearly show that the proposed estimator substantially outperforms several existing estimators in terms of accuracy and achieves a good SNR‐insensitive performance in a wide range of velocities and SNRs. Copyright © 2013 John Wiley & Sons, Ltd.
The molecular genetics of avian sex determination and its manipulation
Authors: Ayers Katie L. , Smith Craig A. , Lambeth Luke S.
Published: February 2013

The chicken (Gallus gallus domesticus) has long been a useful model for developmental biologists. The developing avian embryo is easily accessible and fertile eggs are widely available. In addition, the embryo is also amenable to genetic manipulation allowing studies on many important morphological and cellular processes. More recently, the ability to directly manipulate gene expression through the production of transgenic or mutant chicken embryos by viral delivery methods has been useful to analyse gene function in a wide range of tissues, including the developing gonads. Chickens are amniotes and their development closely resembles that of mammals, implying underlying genetic conservation of key pathways, including sex development. Studies of sex determination and gonadal development in this model are providing insight into avian ovarian and testis developmental pathways and their evolution. Indeed, the chicken embryo is a suitable model for the functional analysis of genes implicated in human disorders of sex development, and studies in this model will complement those carried out in mammalian models such as the mouse. In this review we discuss the current knowledge of sex determination and sexual differentiation in avians, using chicken as model. We review how sex chromosomes contribute to this process and provide current information on our understanding of gonadal sexual differentiation at both the cellular and molecular level in the chicken embryo. Finally, we review the methods currently used to investigate the role of genes and signaling pathways during sexual differentiation, and discuss how these methods may contribute to further understanding of vertebrate gonadogenesis. genesis 51:325–336. © 2013 Wiley Periodicals, Inc.
Cobalt(II)–Porphyrin‐Catalyzed Aerobic Oxidation: Oxidative Coupling of Phenols
Authors: Jiang Qing , Sheng Wenbing , Tian Mi , Tang Jie , Guo Cancheng
Published: February 2013

The first example of the cobalt–porphyrin‐catalyzed aerobic oxidative coupling of phenols through oxidative C–H functionalization has been developed. In the presence of T(p‐OMe)PPCo and Na2CO3, the oxidative coupling of phenols with different substituents proceeded smoothly with O2 as a terminal oxidant to give the corresponding biaryl compounds in satisfactory yields. The biaryl derivatives are important in the area of pharmaceuticals and as ligands in metal catalysis. Preliminary mechanistic studies of this oxidative coupling reaction are also reported.
Copper(II)‐Mediated Synthesis of Indolequinones from Bromoquinones and Enamines
Authors: Inman Martyn , Moody Christopher J.
Published: February 2013

The reaction of enamines and bromoquinones in the presence of copper(II) acetate and potassium carbonate results in a regiospecific synthesis of indolequinones. The reaction is broad in scope and scalable and provides a route to the core structure that is present in several biologically interesting natural and synthetic compounds.
Short migration of methane into a gas hydrate‐bearing sand layer at Walker Ridge, Gulf of Mexico
Authors: Cook Ann E. , Malinverno Alberto
Published: February 2013

The mechanisms governing distribution of natural gas hydrates in marine sediment systems are not well understood. We focus on a hole in the Gulf of Mexico, Walker Ridge Block 313 Hole H, where a 2.5‐m‐thick gas hydrate‐bearing sand occurs within a 152‐m‐thick fine‐grained mud interval containing gas hydrate in fractures. The gas hydrate‐bearing sand is surrounded by two distinct hydrate‐free zones (10‐m‐thick above and 3‐m‐thick below). We hypothesize that microbial methane generated within the hydrate‐free zones diffused into the sand and formed gas hydrate. We show that the amount of methane produced in the hydrate‐free zones is likely enough to explain the gas hydrate content of the sand layer. Additionally, we show that there is enough time for dissolved methane to diffuse from the hydrate‐free zones into the sand. We conclude that methane transport over significant distances via fluid flow is not required but that microbial methane could migrate short distances to form gas hydrate in the sand layer.
Seasonal moisture sources and the isotopic composition of precipitation, rivers, and carbonates across the Andes at 32.5–35.5°S
Authors: Hoke Gregory D. , Aranibar Julieta N. , Viale Maximiliano , Araneo Diego C. , Llano Carina
Published: February 2013

Constraining the influence of different moisture sources across the flanks of mountain ranges is important for understanding tectonic, geomorphic, and paleoclimate problems at geologic timescales, as well as evaluating climate change and water resources on human time scales. The stable isotope compositions of stream waters and precipitation are an ideal tool for this task. This study reports the results of a 2 year monthly precipitation sampling campaign on the eastern flank of the Andes in the Mendoza Province of Argentina, which began in September 2008. A total of 104 precipitation samples spanning some 2500 m of relief from nine sites were analyzed for δD and δ18O. In addition, 81 samples from Andean rivers collected on both sides of the range in 2002 and 2007 were analyzed. We employ a Rayleigh isotope fractionation modeling approach to explore spatial and temporal variations in precipitation and river water compositions. The results indicate that precipitation on the eastern slopes of the Andes at ~33°S, at elevations above 2 km, is largely derived from a westerly, Pacific‐source component and a mixture of easterly and westerly sources below 2 km. Further south at ~35°S, river water compositions exhibit a strong winter influence. At 33°S, rivers have an isotopic minimum of ~ −18‰ across the core of the range, which has an average elevation of 4000 m, and are topographically offset from similar isotopic values of precipitation by +1000 m. Comparison of precipitation and river water data with temperature‐corrected δ18O estimates from pedogenic carbonates illustrates that carbonates capture the range of variability observed in modern precipitation and Rayleigh fractionation models.
Trophic regions of a hydrothermal plume dispersing away from an ultramafic‐hosted vent‐system: Von Damm vent‐site, Mid‐Cayman Rise
Authors: Bennett Sarah A. , Coleman Max , Huber Julie A. , Reddington Emily , Kinsey James C. , McIntyre Cameron , Seewald Jeffrey S. , German Christopher R.
Published: February 2013

Deep‐sea ultramafic‐hosted vent systems have the potential to provide large amounts of metabolic energy to both autotrophic and heterotrophic microorganisms in their dispersing hydrothermal plumes. Such vent‐systems release large quantities of hydrogen and methane to the water column, both of which can be exploited by autotrophic microorganisms. Carbon cycling in these hydrothermal plumes may, therefore, have an important influence on open‐ocean biogeochemistry. In this study, we investigated an ultramafic‐hosted system on the Mid‐Cayman Rise, emitting metal‐poor and hydrogen sulfide‐, methane‐, and hydrogen‐rich hydrothermal fluids. Total organic carbon concentrations in the plume ranged between 42.1 and 51.1 μM (background = 43.2 ± 0.7 μM (n = 5)) and near‐field plume samples with elevated methane concentrations imply the presence of chemoautotrophic primary production and in particular methanotrophy. In parts of the plume characterized by persistent potential temperature anomalies but lacking elevated methane concentrations, we found elevated organic carbon concentrations of up to 51.1 μM, most likely resulting from the presence of heterotrophic communities, their extracellular products and vent larvae. Elevated carbon concentrations up to 47.4 μM were detected even in far‐field plume samples. Within the Von Damm hydrothermal plume, we have used our data to hypothesize a microbial food web in which chemoautotrophy supports a heterotrophic community of microorganisms. Such an active microbial food web would provide a source of labile organic carbon to the deep ocean that should be considered in any future studies evaluating sources and sinks of carbon from hydrothermal venting to the deep ocean.
Depths and temperatures of <10.5 Ma mantle melting and the lithosphere‐asthenosphere boundary below southern Oregon and northern California
Authors: Till Christy B. , Grove Timothy L. , Carlson Richard W. , Donnelly‐Nolan Julie M. , Fouch Matthew J. , Wagner Lara S. , Hart William K.
Published: February 2013

Plagioclase and spinel lherzolite thermometry and barometry are applied to an extensive geochemical dataset of young (<10.5 Ma) primitive basaltic lavas from across Oregon's High Lava Plains, California's Modoc Plateau, and the central‐southern Cascades volcanic arc to calculate the depths and temperatures of mantle melting. This study focuses on basalts with low pre‐eruptive H2O contents that are little fractionated near‐primary melts of mantle peridotite (i.e., basalts thought to be products of anhydrous decompression mantle melting). Calculated minimum depths of nominally anhydrous melt extraction are 40–58 km below Oregon's High Lava Plains, 41–51 km below the Modoc Plateau, and 37–60 km below the central and southern Cascades arc. The calculated depths are very close to Moho depths as determined from a number of regional geophysical studies and suggest that the geophysical Moho and lithosphere‐asthenosphere boundary in this region are located in very close proximity to one another (within 5–10 km). The basalts originated at 1185–1383°C and point to a generally warm mantle beneath this area but not one hot enough to obviously require a plume contribution. Our results, combined with a range of other geologic, geophysical, and geochemical constraints, are consistent with a regional model whereby anhydrous mantle melting over the last 10.5 Ma in a modern convergent margin and back arc was driven by subduction‐induced corner flow in the mantle wedge, and to a lesser extent, toroidal flow around the southern edge of the subducting Juan de Fuca and Gorda plates, and crustal extension‐related upwelling of the shallow mantle.
Delamination vs. break‐off: the fate of continental collision
Authors: Magni Valentina , Faccenna Claudio , van Hunen Jeroen , Funiciello Francesca
Published: February 2013

The fate of a convergent continental margin is investigated. We perform a set of 2D numerical models to study how and why continental collision can evolve in different scenarios. Since the rheology of continental lithosphere has a major control on the dynamics of subduction, we explore a range of different lithosphere and lower crust viscosity values to understand their sensitivity on the possible scenarios. We find that with a rheologically layered crust both delamination and break‐off are feasible. We identify three modes: (1) slab detachment, in which the lithospheric mantle and the crust are strongly coupled, subduction slows down and the slab eventually breaks; (2) delamination of the lithospheric mantle that separates from the crust and continue to subduct and (3) an intermediate mode where the lithospheric mantle and the crust remain partially coupled, resulting in an initial stage of delamination followed by the slow down and cessation of subduction.
Imaging the source regions of normal faulting sequences induced by the 2011 M9.0 Tohoku‐Oki earthquake
Authors: Kato Aitaro , Igarashi Toshihiro , Obara Kazushige , Sakai Shinichi , Takeda Tetsuya , Saiga Atsushi , Iidaka Takashi , Iwasaki Takaya , Hirata Naoshi , Goto Kazuhiko , Miyamachi Hiroki , Matsushima Takeshi , Kubo Atsuki , Katao Hiroshi , Yamanaka Yoshiko , Terakawa Toshiko , Nakamichi Haruhisa , Okuda Takashi , Horikawa Shinichiro , Tsumura Noriko , Umino Norihito , Okada Tomomi , Kosuga Masahiro , Takahashi Hiroaki , Yamada Takuji
Published: February 2013

Intense swarm‐like seismicity associated with shallow normal faulting was induced in Ibaraki and Fukushima prefectures, Japan, following the 2011 Tohoku‐Oki earthquake. This seismicity shows a systematic spatiotemporal evolution, but little is known of the heterogeneity in crustal structure in this region, or its influence on the evolution of the seismicity. Here, we elucidate a high‐resolution model of crustal structure in this region and determine precise hypocenter locations. Hypocenters in Ibaraki Prefecture reveal a planar earthquake alignment dipping SW at ~45°, whereas those in Fukushima Prefecture show a more complex distribution, consisting of conjugate sets of aligned small earthquakes. On the north of the hypocenter of the largest earthquake in the sequence (the M7.0 Iwaki earthquake), we imaged a high‐velocity body at shallow depths that lacks aftershock seismicity. Based on fault source models, the large‐slip region of the Iwaki earthquake is situated along a zone that roughly coincides with this high‐velocity body. We delineated a separate low‐velocity anomaly directly beneath the hypocenter of the Iwaki earthquake, indicating crustal fluids in this region. We hypothesize that strong crust underwent structural failure due to the infiltration of crustal fluids into the seismogenic zone from deeper levels, causing the Iwaki earthquake.
Economic crisis detected from space: Air quality observations over Athens/Greece
Authors: Vrekoussis M. , Richter A. , Hilboll A. , Burrows J. P. , Gerasopoulos E. , Lelieveld J. , Barrie L. , Zerefos C. , Mihalopoulos N.
Published: February 2013

Using both satellite observations of tropospheric NO2 columns and a number of economic metrics, we investigate the impact of the economic crisis (from 2008 onward) on air quality over Greece, and Athens in particular. The multiannual analysis shows that NO2 columns over Athens have been significantly reduced in the range 30–40%. This decline is further supported by surface measurements of atmospheric NO2 mixing ratios. Additionally, the declining local concentrations of NO, CO, and SO2 are associated with an increase in ozone due to reduced titration by NO. In particular, regression analysis revealed that the reduction of NO2 (0.3 ± 0.2 ppbv y−1) and SO2 (0.2 ± 0.1 ppbv y−1) during the period 2000–2007, significantly accelerated during the economic crisis period (from 2008 onward), reaching 2.3 ± 0.2 ppbv y−1 and 0.7 ± 0.1 ppbv y−1, respectively. The strong correlations between pollutant concentrations and economic indicators show that the economic recession has resulted in proportionally lower levels of pollutants in large parts of Greece.
NF3: UV absorption spectrum temperature dependence and the atmospheric and climate forcing implications
Authors: Papadimitriou Vassileios C. , McGillen Max R. , Fleming Eric L. , Jackman Charles H. , Burkholder James B.
Published: February 2013

Nitrogen trifluoride (NF3) is an atmospherically persistent greenhouse gas that is primarily removed by UV photolysis and reaction with O(1D) atoms. In this work, the NF3 gas‐phase UV absorption spectrum, σ(λ,T), was measured at 16 wavelengths between 184.95 and 250 nm at temperatures between 212 and 296 K. A significant spectrum temperature dependence was observed in the wavelength region most relevant to atmospheric photolysis (200–220 nm) with a decrease in σ(210 nm,T) of ~45% between 296 and 212 K. Atmospheric photolysis rates and global annually averaged lifetimes of NF3 were calculated using the Goddard Space Flight Center 2‐D model and the σ(λ,T) parameterization developed in this work. Including the UV absorption spectrum temperature dependence increased the stratospheric photolysis lifetime from 610 to 762 years and the total global lifetime from 484 to 585 years; the NF3 global warming potentials on the 20‐, 100‐, and 500‐year time horizons increased <0.3, 1.1, and 6.5% to 13,300, 17,700, and 19,700, respectively.
Nucleation and seismic tremor associated with the glacial earthquakes of Whillans Ice Stream, Antarctica
Authors: Paul Winberry J. , Anandakrishnan Sridhar , Wiens Douglas A. , Alley Richard B.
Published: February 2013

The ability to monitor transient motion along faults is critical to improving our ability to understand many natural phenomena such as landslides and earthquakes. Here, we usedata from a GPS and seismometer network that were deployed to monitor the regularly repeating glacial earthquakes of Whillans Ice Stream, West Antarctica to show that a unique pattern of precursory slip precedes complete rupture along the bed of the ice stream. Additionally, we show that rupture can be independently tracked by increased levels of microseismic activity, including harmonic tremor, that are coincident with the onset of slip at any location, thus providing a remote means of monitoring stress and rupture propagation during the glacial earthquakes.
Thermal elasticity of (Fex,Mg1−x)2SiO4 olivine and wadsleyite
Authors: Núñez‐Valdez M. , Wu Z. , Yu Y. G. , Wentzcovitch R. M.
Published: February 2013

We present first‐principles results for elastic moduli (bulk, K, and shear, G) and acoustic velocities (compressional, VP, shear, VS, and bulk VΦ) of olivine (α) and wadsleyite (β) (Fex,Mg1 − x)2SiO4, at high pressure (P) and temperature (T) with varying iron content (0 ≤ x ≤ 0.125). Pressure and temperature derivatives of these properties are analyzed. We show that adding 12.5% of Fe in forsterite softens VP and VS by ∼3–6%, the same effect as raising temperature by ∼1000 K in dry olivine at 13.5 GPa—the same is true in wadsleyite. This study suggests that Fe is effective in producing seismic velocity heterogeneity at upper mantle and transition zone conditions and should be another key ingredient, in addition to temperature and water content variations, in interpreting seismic heterogeneities in the transition zone. The effect of Fe on density, elastic, and velocity contrasts across the α → β transition is also addressed at relevant conditions. We show that simultaneous changes of composition, temperature, and pressure do not affect significantly the relative density contrasts. We also find that compressional and shear impedance contrasts result primarily from velocity discontinuities rather than density discontinuity.
Real‐time high‐rate co‐seismic displacement from ambiguity‐fixed precise point positioning: Application to earthquake early warning
Authors: Li Xingxing , Ge Maorong , Zhang Xiaohong , Zhang Yong , Guo Bofeng , Wang Rongjiang , Klotz Jürgen , Wickert Jens
Published: February 2013

Nowadays more and more high‐rate real‐time GPS data become available that provide a great opportunity to contribute to earthquake early warning (EEW) system in terms of capturing regional surface displacements, as an independent information source, useful for promptly estimating the magnitude of large destructive earthquake. In our study, we demonstrate the performance of the real‐time ambiguity‐fixed precise point positioning (PPP) approach using 5 Hz GPS data collected during El Mayor‐Cucapah earthquake (Mw 7.2, 4 April 2010). The PPP‐based displacements show to agree with accelerometer‐based displacement at centimeter level. The key for successfully obtaining high precision displacements is the efficient ambiguity resolution. PPP with ambiguity fixing can result in correct permanent co‐seismic offsets and correct recovery of moment magnitude and fault slip inversion at levels comparable to post‐processing.
High predictive skill of global surface temperature a year ahead
Authors: Folland Chris K. , Colman Andrew W. , Smith Doug M. , Boucher Olivier , Parker David E. , Vernier Jean‐Paul
Published: February 2013

We discuss 13 real‐time forecasts of global annual‐mean surface temperature issued by the United Kingdom Met Office for 1 year ahead for 2000–2012. These involve statistical, and since 2008, initialized dynamical forecasts using the Met Office DePreSys system. For the period when the statistical forecast system changed little, 2000–2010, issued forecasts had a high correlation of 0.74 with observations and a root mean square error of 0.07°C. However, the HadCRUT data sets against which issued forecasts were verified were biased slightly cold, especially from 2004, because of data gaps in the strongly warming Arctic. This observational cold bias was mainly responsible for a statistically significant warm bias in the 2000–2010 forecasts of 0.06°C. Climate forcing data sets used in the statistical method, and verification data, have recently been modified, increasing hindcast correlation skill to 0.80 with no significant bias. Dynamical hindcasts for 2000–2011 have a similar correlation skill of 0.78 and skillfully hindcast annual mean spatial global surface temperature patterns. Such skill indicates that we have a good understanding of the main factors influencing global mean surface temperature.
Relative sea level variations in the Chukchi region ‐ Arctic Ocean ‐ since the late Eocene
Authors: Hegewald Anne , Jokat Wilfried
Published: February 2013

Relative sea level (RSL) variations are a result of tectonic activity, changing of the water volume in ocean basins (e.g. due to increasing/decreasing of ice volume, evaporation) and variations in regional to global climate, which influence erosional processes and material transport. We present multi‐channel seismic data combined with dated sediment horizons from the Chukchi Shelf, Arctic Ocean. Based on a series of prograding sequences in the upper 4 km of sediments and the method of seismic sequence stratigraphy, we introduce the first RSL curve for the Chukchi region, beginning in the late Eocene (40 Ma). The comparison of the Chukchi RSL curve with the global RSL curve shows that RSL lowering events in the Chukchi region do not correlate with global events for the Eocene/Oligocene ‐ early Miocene. Between the Eocene/Oligocene and the late Oligocene, the Chukchi RSL variations were small (< 100 m). Since the late Oligocene the Chukchi RSL increased until the opening of the Fram Strait in the early Miocene. We show that the Chukchi RSL variations are representative for the Arctic Ocean, and conclude that the Arctic Ocean was an isolated basin for the Eocene/Oligocene ‐ early Miocene.
Decadal prediction of observed and simulated sea surface temperatures
Authors: DelSole Timothy , Jia Liwei , Tippett Michael K.
Published: February 2013

A multivariate regression model derived from climate model simulations is shown to produce skillful predictions of unforced, annual mean sea surface temperature variations on multiyear time scales in observations and climate model simulations. Patterns that can be predicted with skill are identified explicitly and shown to arise from a combination of persistence and coupled interactions in the Pacific Ocean. Adding the regression model predictions to an estimate of the response to anthropogenic and natural forcing yields a prediction with higher skill than either alone, demonstrating the contribution of initial condition information to skill on multiyear time scales.
The impact of an intense summer cyclone on 2012 Arctic sea ice retreat
Authors: Zhang Jinlun , Lindsay Ron , Schweiger Axel , Steele Michael
Published: February 2013

This model study examines the impact of an intense early August cyclone on the 2012 record low Arctic sea ice extent. The cyclone passed when Arctic sea ice was thin and the simulated Arctic ice volume had already declined ~40% from the 2007–2011 mean. The thin sea ice pack and the presence of ocean heat in the near surface temperature maximum layer created conditions that made the ice particularly vulnerable to storms. During the storm, ice volume decreased about twice as fast as usual, owing largely to a quadrupling in bottom melt caused by increased upward ocean heat transport. This increased ocean heat flux was due to enhanced mixing in the oceanic boundary layer, driven by strong winds and rapid ice movement. A comparison with a sensitivity simulation driven by reduced wind speeds during the cyclone indicates that cyclone‐enhanced bottom melt strongly reduces ice extent for about 2 weeks, with a declining effect afterward. The simulated Arctic sea ice extent minimum in 2012 is reduced by the cyclone but only by 0.15 × 106 km2 (4.4%). Thus, without the storm, 2012 would still have produced a record minimum.
Analytical solution for slip flow and heat transfer due to a stretching sheet
Authors: Nandeppanavar Mahantesh M. , Siddalingappa M.N. , Satyanarayana A.V.V. , Kemparaju M.C.
Published: February 2013

An analysis has been carried out to investigate the analytical solution to the flow and heat transfer characteristics of a viscous flow over a stretching sheet in the presence of second‐order slip in flow. The governing partial differential equations of flow and heat transfer are converted into non‐linear ordinary differential equations by using suitable similarity transformations. The exact solution of momentum equation is assumed in exponential form and analytical solutions of heat transfer for both PST and PHF cases are obtained by the power series method in terms of Kummer's hypergeometric function. The temperature profiles are drawn for different governing parameters. The numerical values of wall temperature gradient and wall temperature are compared with earlier numerical results which have a good agreement. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21044
A SIMPLIFIED METHODOLOGY FOR IDENTIFYING THE FUNCTION OF ELOPEMENT
Authors: Lehardy Robert K. , Lerman Dorothea C. , Evans Lindsay M. , O'Connor Alyson , LeSage Daniel L.
Published: February 2013

Functional analyses of elopement (i.e., leaving a specific area without permission) are challenging to conduct because clients must have repeated opportunities to elope from one room (or area) to another safely. These analyses often require two or more adjoining rooms and retrieval of the client following each instance of elopement (e.g., Piazza et al., 1997). These room arrangements may be impractical in some settings, and therapist delivery of attention or demands during retrieval may confound the results. To address these issues, we evaluated the viability of conducting a functional analysis (FA) of elopement within a single room. Participants were 2 children and 2 adults with developmental disabilities who eloped from rooms at their day programs. Results of the single‐room assessments were compared to those of a second FA that was conducted using methods similar to those described in previous studies. Function‐based treatments were implemented for each participant. Results suggest that the single‐room assessment may be a viable alternative for identifying the function of elopement.
The Intramembrane Protease SPPL2A Is Critical for Tooth Enamel Formation
Authors: Bronckers Antonius LJJ , Gueneli Nur , Lüllmann-Rauch Renate , Schneppenheim Janna , Moraru Andreea P , Himmerkus Nina , Bervoets Theodore J , Fluhrer Regina , Everts Vincent , Saftig Paul , Schröder Bernd
Published: February 2013

Intramembrane proteases are critically involved in signal transduction and membrane protein turnover. Signal-peptide-peptidase-like 2a (SPPL2A), a presenilin-homologue residing in lysosomes/late endosomes, cleaves type II-oriented transmembrane proteins. We recently identified SPPL2A as the enzyme controlling turnover and functions of the invariant chain (CD74) of the major histocompatibility complex II (MHCII) and demonstrated critical importance of this process for B cell development. Surprisingly, we found that SPPL2A is critical for formation of dental enamel. In Sppl2a knockout mice, enamel of the erupted incisors was chalky white and rapidly eroded after eruption. SPPL2A was found to be expressed in enamel epithelium during secretory and maturation stage amelogenesis. Mineral content of enamel in Sppl2a−/− incisors was inhomogeneous and reduced by ∼20% compared to wild-type mice with the most pronounced reduction at the mesial side. Frequently, disruption of the enamel layer and localized detachment of the most superficial enamel layer was observed in the knockout incisors leading to an uneven enamel surface. In Sppl2a null mice, morphology and function of secretory stage ameloblasts were not noticeably different from that of wild-type mice. However, maturation stage ameloblasts showed reduced height and a characteristic undulation of the ameloblast layer with localized adherence of the cells to the outer enamel. This was reflected in a delayed and incomplete resorption of the proteinaceous enamel matrix. Thus, we conclude that intramembrane proteolysis by SPPL2A is essential for maintaining cellular homeostasis of ameloblasts. Because modulation of SPPL2A activity appears to be an attractive therapeutic target to deplete B cells and treat autoimmunity, interference with tooth enamel formation should be investigated as a possible adverse effect of pharmacological SPPL2A inhibitors in humans.
Exendin-4, a Glucagon-Like Peptide-1 Receptor Agonist, Prevents Osteopenia by Promoting Bone Formation and Suppressing Bone Resorption in Aged Ovariectomized Rats
Authors: Ma Xue , Meng Jingru , Jia Min , Bi Long , Zhou Ying , Wang Yukun , Hu Jing , He Gonghao , Luo Xiaoxing
Published: February 2013

Osteoporosis mainly affects postmenopausal women and older men. Gastrointestinal hormones released after meal ingestion, such as glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide (GLP)-2, have been shown to regulate bone turnover. However, whether GLP-1, another important gastrointestinal hormone, and its analogues also have antiosteoporotic effects, especially in aged postmenopausal situation, has not been confirmed. In the present study, we evaluated the effects of the GLP-1 receptor agonist exendin-4 on ovariectomy (OVX)-induced osteoporosis in old rats. Twelve-month-old female Sprague-Dawley rats were subjected to OVX, and exendin-4 was administrated 4 weeks after the surgery and lasted for 16 weeks. Bone characters and related serum and gene biomarkers were analyzed. Sixteen weeks of treatment with exendin-4 slowed down body weight gain by decreasing fat mass and prevented the loss of bone mass in old OVX rats. Exendin-4 also enhanced bone strength and prevented the deterioration of trabecular microarchitecture. Moreover, exendin-4 decreased the urinary deoxypyridinoline (DPD)/creatinine ratio and serum C-terminal cross-linked telopeptides of type I collagen (CTX-I) and increased serum alkaline phosphatase (ALP), osteocalcin (OC), and N-terminal propeptide of type 1 procollagen (P1NP) levels, key biochemical markers of bone turnover. Interestingly, gene expression results further showed that exendin-4 not only inhibited bone resorption by increasing the osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL) ratio, but also promoted bone formation by increasing the expression of OC, Col1, Runx2, and ALP, which exhibited dual regulatory effects on bone turnover as compared with previous antiosteoporotic agents. In conclusion, these findings demonstrated for the first time the antiosteoporotic effects of exendin-4 in old OVX rats and that it might be a potential candidate for treatment of aged postmenopausal osteoporosis.