bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroalumination versus Deprotonation of Alkynes with Sterically Demanding Substituents
Authors: Uhl Werner , Layh Marcus , Rhotert Ines , Wollschläger Agnes , Hepp Alexander
Published: July 2013

Treatment of sterically highly shielded terminal alkynes, H-C≡C-aryl, with dialkylaluminium and dialkylgallium hydrides, R2E-H, afforded by hydrogen release dimeric dialkylelement alkynides with a four-membered E2C2 heterocycle independent of the bulk of the aryl groups. A rare example of a monomeric alkynylaluminium compound was only obtained with very bulky CH(SiMe3)2 groups attached to the metal atoms and by salt elimination reaction. The steric shielding by the bulky aryl groups did not prevent condensation reactions. Hydroalumination of 1-(trimethylsilyl)-2-(2,6- dimethylphenyl)ethyne using Me2Al-H resulted in a divinyl compound by elimination of trimethylaluminium
Ligand Exchange at a Gold(I) Carbene Complex
Authors: Jahnke Mareike C. , Pape Tania , Hahn F. Ekkehardt
Published: July 2013

Gold complex [AuCl(NHC)] (NHC=N,N0-dipropylbenzimidazolin-2-ylidene) 1 undergoes facile substitution reactions at the gold(I) center. Treatment of 1 with anionic phenylacetylide or thiophenolate led to the neutral gold complexes 2 and 3, respectively. The cationic gold complexes [Au(NHC)(pyridine)](BF4) [4]BF4 and [Au2(NHC)2(4,4'-bipyridine)](BF4)2 [5](BF4)2 were obtained via abstraction of the chloro ligand from 1 and reaction with the appropriate amine. Reaction of 1 with AgBF4 in the presence of PPh3 instead of an amine led to an inseparable product mixture of the mixed NHC=PPh3 complex [6]BF4, the dicarbene complex [Au(NHC)2]BF4, [7]BF4, and [Au(PPh3)2]BF4, [8]BF4. Crystals of 2 and [6]BF4 were obtained, and X-ray diffraction structure analyses revealed that the gold(I) atoms are coordinated in a linear fashion by the NHC and the co-ligand
Syntheses and Crystal Structures of the Bromide-derivatized Lanthanoid(III) Ortho-Oxomolybdates(VI) LnBr[MoO4] (Ln = Pr, Nd, Sm, Gd– Lu)
Authors: Schustereit Tanja , Henning Harald , Schleid Thomas , Hartenbach Ingo
Published: July 2013

The lanthanoid(III) bromide ortho-oxomolybdates(VI) LnBr[MoO4] (Ln = Pr, Nd, Sm, Gd - Lu) crystallize triclinically in the space group P1 (a=686 - 689, b=713 - 741, c=1066 - 1121 pm, a =103 - 106, b =107 - 108, g = 92 - 95°) with Z =4. The crystal structure contains two crystallographically distinguishable Ln3+ cations, each one with a coordination number of seven plus one. (Ln1)3+ is surrounded by three bromide and four plus one oxide anions, while for (Ln2)3+ just one bromide and six plus one oxide anions belong to the coordination sphere. Considering the smallest lanthanoids, however, the distances to the farthest anions increase so much that their contribution to the coordination spheres becomes negligible in both cases. The polyhedra around (Ln1)3+ are connected to each other via common edges, which consist of two crystallographically identical Br- anions (Br1). Furthermore, the common structure of the LnBr[MoO4] series contains two crystallographically different, discrete [MoO4]2- ortho-oxomolybdate(VI) tetrahedra. Two plus one oxygen atoms of each [(Mo1)O4]2- unit are used to interconnect the polyhedra around (Ln1)3+ and (Ln2)3+ together with one Br- anion (Br2). The connection between two polyhedra around (Ln2)3+ is generated exclusively by two plus one oxygen atoms of two [(Mo2)O4]2- anions. The complete structural arrangement can be considered as a bundle of primitively packed 1
¥{LnBr[MoO4]} chains with two alternating motifs of linkage, which are running parallel along [012].
IceBridge Airborne Survey Data Support Arctic Sea Ice Predictions
Authors: Kurtz Nathan , Richter‐Menge Jackie , Farrell Sinead , Studinger Michael , Paden John , Sonntag John , Yungel Jim
Published: July 2013

Since 2009, NASA's Operation IceBridge mission has conducted large‐scale airborne surveys of the Arctic and provided data on sea ice properties as standard products. Data from those surveys are now being processed using a quick‐production method that makes preliminary observations of sea ice properties available within 1 month after the completion of the flights. These data sets provide new avenues for the assessment and prediction of Arctic sea ice properties.
Continuous GPS Network Operating Throughout Ecuador
Authors: Mothes Patricia A. , Nocquet Jean‐Mathieu , Jarrín Paul
Published: July 2013

Recent devastating great earthquakes in Sumatra, Chile, and Japan show that scientists need to learn more about other less studied subduction zones that have also generated major earthquakes in the recent past. On the margin of northwest South America, offshore Ecuador and Colombia, the Nazca plate's rapid oblique subduction beneath the South American continent has produced a sequence of large earthquakes. A recently installed continuous GPS network is beginning to help scientists learn more about the geodynamic framework in Ecuador.
Nature of the Interfaces Between Stoichiometric and Under‐Stoichiometric MoO3 and 4,4′‐N,N′‐dicarbazole‐biphenyl: A Combined Theoretical and Experimental Study
Authors: Papadopoulos Theodoros A. , Meyer Jens , Li Hong , Guan Zelei , Kahn Antoine , Brédas Jean‐Luc
Published: July 2013

A combination of density functional theory and experimental measurements via ultraviolet and X‐ray photoelectron spectroscopies is used to explore the nature of the interface between the stoichiometric molybdenum trioxide (MoO3) or its under‐stoichiometric counterpart with oxygen vacancies, and an organic hole‐transport layer represented by 4,4′‐N,N′‐dicarbazole‐biphenyl (CBP). Upon adsorption of CBP, special attention is paid to i) the appearance of gap states and the reduction of the molybdenum oxide surface, and ii) the evolution of the work function. Very good agreement is found between theory and experiment. The near alignment of the CBP highest occupied molecular orbital with the Fermi level and the conduction band edge of molybdenum oxide points to facile hole collection or injection.
Modulation of food texture using controlled heteroaggregation of lipid droplets: Principles and applications
Authors: Mao Yingyi , McClements David Julian
Published: June 2013

This article reviews the development and potential application of novel food‐grade materials based on heteroaggregation of oppositely charged particles. These particles typically consist of a hydrophobic lipid core and an electrically charged emulsifier shell. Heteroaggregation leads to the formation of emulsion‐based products that are highly viscous or gel‐like at much lower droplet concentrations than in nonaggregated systems. Heteroaggregation may therefore be useful for developing food products with novel textural characteristics or for creating reduced‐calorie versions of full fat foods. We give an overview of the principles of heteroaggregation, the relationship between emulsion microstructure and texture, and possible commercial applications of this method. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3833–3841, 2013
Dual stimuli responsive glycidyl methacrylate chitosan‐quaternary ammonium hybrid hydrogel and its bovine serum albumin release
Authors: He Mingyu , Chu Chih‐Chang
Published: June 2013

A new family of cationic hybrid hydrogels from two new positively charged aqueous soluble precursors, glycidyl methacrylate‐chitosan (GMA‐chitosan), and 2‐(acryloyloxy) ethyl trimethylammonium (AETA), was developed via a simple photocrosslinking fabrication method. These hybrid hydrogels have pendant quaternary ammonium functional groups on the AETA segments. The chemical composition of GMA‐chitosan/AETA hybrid hydrogels were characterized by Fourier transform infrared spectroscopy and their mechanical, swelling, and morphological properties were examined as a function of the composition of the hybrids as well as the effect of pH and ionic strength of the surrounding medium. GMA‐chitosan/AETA hybrid hydrogels show a porous network structure with average pore diameter 20–50 μm. The compression moduli of these hybrid hydrogels ranged from 27.24 to 28.94 kPa, which are significantly higher than a pure GMA‐chitosan (17.64 kPa). GMA‐chitosan/AETA hybrid hydrogel shows pH/ionic strength responsive swelling behavior because of the presence of the positive charge pendant groups. These hybrid hydrogels showed a sustained BSA protein release and a significantly lower initial burst release than a pure GMA‐chitosan hydrogel. The two aqueous soluble precursors and the cationic charge characteristics of the resulting GMA‐chitosan/AETA hybrid hydrogels may suggest that this new family of biomaterials may have promising applications as the pH responsive protein drug delivery vehicles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3736–3745, 2013
Effects of surfactants on the microstructures of electrospun polyacrylonitrile nanofibers and their carbonized analogs
Authors: Aykut Yakup , Pourdeyhimi Behnam , Khan Saad A.
Published: June 2013

In this study, the influence of surfactants on the processability of electrospun polyacrylonitrile (PAN) nanofibers and their carbonized analogs was investigated. The surfactants employed in this effort are Triton X‐100 (nonionic surfactant, SF‐N), sodium dodecyl sulfate (SDS) (anionic surfactant, SF‐A), and hexadecyltrimethylammonium bromide (HDTMAB) (cationic surfactant, SF‐C). Interactions between electrospun PAN and the surfactants, reflected in effects on as‐spun and carbonized nanofiber morphologies and microstructures, were explored. The results show that uniform nanofibers are obtained when cationic and anionic surfactants (surfactant free and nonionic surfactants) are utilized in the preparation of electrospun PAN. In contrast, a bead‐on‐a‐string morphology results when the aniconic and cationic surfactants are present, and defect structure is enhanced with cationic surfactant addition. Moreover, fiber breakage is observed when the nonionic surfactant Triton X‐100 is employed for electrospinning. After carbonizaition, the PAN polymers were observed to have less ordered structures with addition of any type of surfactant used for electrospinning and the disorder becomes more pronounced when the anionic surfactant is utilized. Owing to the fact that microstructure defects create midband gap states that enable more electrons to be emitted from the fiber, an enhancement of electron emission is observed for PAN electrospun in the presence of the anionic surfactant. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3726–3735, 2013
Hydrophobic and oil‐resistant coatings based on advanced green polyurethane dispersions
Authors: Rengasamy Senthilkumar , Mannari Vijay
Published: July 2013

In recent years, there have been significant interests among scientists around the world to design smart coatings that combine the standard desirable mechanical and chemical resistance properties with additional functionalities such as oil and water repellency, hydrophobicity, self‐cleaning and gas barrier properties. In the present research work, advanced aqueous polyurethane dispersion (PUD) systems have been designed and developed using three different types of polyols as soft‐segments. These polyols differ in their chemical structure, functionality, polarity, and interfacial properties. The effects of soy‐based polyol, hydroxy‐terminated perfluoropolyether, and hydroxy‐terminated polydimethylsiloxane—on various mechanical properties of their uncross‐linked and cross‐linked films, and more specifically on their hydrophobicity and oil‐resistance (oleophobicity) have been studied. Hydrophobicity of these coatings has been characterized by their Dynamic Contact Angle measurements and their oleophobicity by n‐octane absorption method. The investigations showed that presence of fluorine and siloxane structures significantly improve the hydrophobicity and oil resistance of these coatings and it is possible to optimize these properties using suitable composition of PUDs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3874–3884, 2013
Nickel‐multiwalled carbon nanotubes/polyvinylidene fluoride composites with high dielectric permittivity
Authors: Yang Dan‐dan , Xu Hai‐ping , Wang Jing‐rong , Wu Yi‐hua
Published: June 2013

Composites with nickel particles coated multiwalled carbon nanotubes (Ni‐MWNTs) embedded into polyvinylidene fluoride (PVDF) were prepared by solution blending and hot‐press processing. The morphology, structure, crystallization behavior, and dielectric properties of composites were studied. The results showed that the crystallization of PVDF was affected by Ni‐MWNTs. With the increment of Ni‐MWNTs, the content of β‐phase in PVDF increased. The dielectric permittivity was as high as 290 at 103 Hz when the weight fraction of Ni‐MWNTs was 10%. The results can be explained by the space charge polarization at the interfaces between the insulator and the conductor, and the formation of microcapacitance structure. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3746–3752, 2013
Influence of the reaction temperature on polyaniline morphology and evaluation of their performance as supercapacitor electrode
Authors: Kuang Hao , Cao Qi , Wang Xianyou , Jing Bo , Wang Qiang , Zhou Ling
Published: June 2013

The polyaniline (PANI) nanostructures of tubular, spherical, and granules morphologies were synthesized by chemical oxidation approach in different reaction temperatures and used as the active electrode materials of symmetric redox supercapacitors. X‐ray diffraction and scanning electron microscopy techniques are employed for characterization of these PANIs. With the initial and reaction temperature increase, the morphology of PANI turned from block to spherical and tubular. Electrochemical properties of these PANI electrodes are studied by cyclic voltammetry (CV), agalvanostatic charge–discharge test, and electrochemical impedance spectroscopy (EIS) in 1M H2SO4 aqueous solution. The highest electrochemical properties are obtained on the PANI with tubular morphology. The initial specific capacitance of tubular, spherical, and granules PANI are about 300, 300, and 290 F g−1 at a constant current of 5 mA. Meanwhile, the retention of the tubular PANI capacitance after 500 charge–discharge cycles was 75%, whereas the spherical and granules PANI was only 35% and 57%. The results indicate that tubular PANI electrodes have potential applications as high‐performance supercapacitors electrode materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3753–3758, 2013
Poly(l‐lactide)/poly(d‐lactide)/multiwalled carbon nanotubes nanocomposites: Enhanced dispersion, crystallization, mechanical properties, and hydrolytic degradation
Authors: Dong Qinglin , Li Yi , Han Changyu , Zhang Xin , Xu Kun , Zhang Huiliang , Dong Lisong
Published: July 2013

Biodegradable stereocomplex‐type poly(l‐lactide) (PLLA)/poly(d‐lactide) (PDLA)/multiwalled carbon nanotubes (MWCNTs) nanocomposites are prepared via simple melt blending method at PDLA loadings from 5 to 20 wt %. Formation of the stereocomplex crystals in the nanocomposites is confirmed by the phase transition in the differential scanning calorimetric profiles. Field emission scanning electron microscopy observation indicates that MWCNTs are nicely dispersed in the PLLA/PDLA/MWCNTs ternary blends with 20 wt % PDLA loading due to the increased shear stress in the melt‐compounding with presence of PDLA. The overall crystallization rates are faster in the PLLA/PDLA/MWCNTs nanocomposites than in PLLA/MWCNTs nanocomposite; however, the crystallization mechanism and crystal structure of these nanocomposites remain unchanged despite the presence of PDLA. The storage modulus above glass transition temperature has been apparently improved in the PLLA/PDLA/MWCNTs nanocomposites with respect to PLLA/MWCNTs nanocomposite. It is interesting to find that the hydrolytic degradation rates have been enhanced obviously in the PLLA/PDLA/MWCNTs nanocomposites than in PLLA/MWCNTs nanocomposite, which may be of great use and importance for the wider practical application of PLLA/MWCNTs nanocomposites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3919–3929, 2013
The extreme forecast index at the seasonal scale
Authors: Dutra E. , Diamantakis M. , Tsonevsky I. , Zsoter E. , Wetterhall F. , Stockdale T. , Richardson D. , Pappenberger F.
Published: June 2013

The extreme forecast index (EFI) concept has been applied to the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasts (S4) of 2‐m temperature (T2M) and total precipitation (TP) using a novel semi‐analytical technique. Results derived from synthetic data highlight the importance of large ensemble sizes to reduce the EFI calculation uncertainty due to sampling. This new diagnostic complements current diagnostics as exemplified for the 2012 warm summer in south central and eastern Europe. The EFI provides an integrated measure of the difference between a particular seasonal forecast ensemble and the underlying model climate which can be used as an early warning indicator.
Association of baseline C‐reactive protein levels with periprocedural myocardial injury in patients undergoing percutaneous bifurcation intervention: A CACTUS study subanalysis
Authors: Niccoli Giampaolo , Sgueglia Gregory A. , Latib Azeem , Crea Filippo , Colombo Antonio ,   on behalf of the CACTUS Study Group
Published: June 2013

Objectives

To assess the predictive value of C‐reactive protein (CRP) on periprocedural myocardial injury (PMI), evaluated by creatine kinase‐myocardial band isoform (CK‐MB) elevation in patients undergoing percutaneous coronary intervention (PCI) with drug‐eluting stent (DES) implantation for the treatment of coronary bifurcation lesions is actually unknown.

Background

Systemic inflammation as assessed by CRP has been associated with averse events after DES implantation. After PCI, the occurrence of PMI is common and has also been associated with worse outcomes. Finally, bifurcations are frequently encountered anatomically complex lesions which the treatment is associated with higher complication rate compared with simple lesions.

Methods

A total of 96 patients (66 ± 10 years, 70 men) from the Coronary bifurcations: Application of the Crushing Technique Using Sirolimus‐eluting stents (CACTUS) trial who had baseline CRP dosage and both baseline and postprocedural CK‐MB measurement were included.

Results

A complex bifurcation strategy was implemented in 53 (55%) patients, and angiographic success was achieved in all but two (2%) patients. Periprocedural myocardial necrosis (increase of CK‐MB between one and three times the upper limit of normal [ULN]) was observed in 12 (13%) patients, and four (4%) patients had PCI‐related myocardial infarction (increase of CK‐MB more than three times ULN). Notably, progressively higher CRP levels were observed in patients with different increase in CK‐MB (P = 0.041). Moreover, CRP >1 mg/L significantly predicted CK‐MB rise (odds ratio 5.6, 95% confidence interval 1.5–4.3, P = 0.011).

Conclusion

In the setting of true coronary bifurcations treated by DES, baseline CRP levels were significantly associated with both the incidence and the extent of PMI. © 2013 Wiley Periodicals, Inc.
Synthesis and Optical Properties of Water‐Soluble Polyglycerol‐Dendronized Rylene Bisimide Dyes
Authors: Heek Timm , Würthner Frank , Haag Rainer
Published: July 2013

Four new water‐soluble polyglycerol‐dendronized perylene, terrylene, and quaterrylene bisimides have been synthesized and characterized with respect to their optical properties in polar organic solvents and water by using UV/Vis and fluorescence spectroscopy. All of these dyes were highly soluble in water, but the size of the chosen polyglycerol dendron was only sufficient to completely suppress dye aggregation for the core‐unsubstituted perylene derivative. Their high solubility in water and their absorption and emission wavelengths up to the NIR region make the core‐unsubstituted perylene and terrylene bisimides ideal candidates for applications in bioimaging, whilst the lack of fluorescence for quaterrylene bisimide in all polar solvents does not warrant further investigation of this chromophore in fluorescence and imaging applications. Likewise, tuning of the emission of rylene bisimides towards longer wavelengths by employing electron‐donating bay substituents is not a promising strategy, owing to the lower fluorescence quantum yields in polar solvents and, in particular, in water.
Rational Design for Cooperative Recognition of Specific Nucleobases Using β‐Cyclodextrin‐Modified DNAs and Fluorescent Ligands on DNA and RNA Scaffolds
Authors: Futamura Akika , Uemura Asuka , Imoto Takeshi , Kitamura Yusuke , Matsuura Hirotaka , Wang Chun‐Xia , Ichihashi Toshiki , Sato Yusuke , Teramae Norio , Nishizawa Seiichi , Ihara Toshihiro
Published: July 2013

We propose a binary fluorimetric method for DNA and RNA analysis by the combined use of two probes rationally designed to work cooperatively. One probe is an oligonucleotide (ODN) conjugate bearing a β‐cyclodextrin (β‐CyD). The other probe is a small reporter ligand, which comprises linked molecules of a nucleobase‐specific heterocycle and an environment‐sensitive fluorophore. The heterocycle of the reporter ligand recognizes a single nucleobase displayed in a gap on the target labeled with the conjugate and, at the same time, the fluorophore moiety forms a luminous inclusion complex with nearby β‐CyD. Three reporter ligands,MNDS(naphthyridine–dansyl linked ligand),MNDB(naphthyridine–DBD), andDPDB(pyridine–DBD), were used for DNA and RNA probing with 3′‐end or 5′‐end modified β‐CyD–ODN conjugates. For the DNA target, the β‐CyD tethered to the 3′‐end of the ODN facing into the gap interacted with the fluorophore sticking out into the major groove of the gap site (MNDSandDPDB). Meanwhile the β‐CyD on the 5′‐end of the ODN interacted with the fluorophore in the minor groove (MNDBandDPDB). The results obtained by this study could be a guideline for the design of binary DNA/RNA probe systems based on controlling the proximity of functional molecules.
Multivariate one‐sided tests for nonlinear mixed‐effects models
Authors: Wang Tao , Wu Lang
Published: July 2013

Multivariate one‐sided hypotheses testing problems arise frequently in practice. Various tests have been developed, but mainly focused on multivariate normal distributions or contingency tables. In this article, motivated by HIV viral dynamic models, we study multivariate one‐sided tests in nonlinear mixed‐effects (NLME) models, for which no previous research has been carried out. We propose a likelihood ratio test (LRT), a Wald test, and a score test. Theoretical results are presented and computational issues are discussed. The proposed methods are evaluated using simulations. A real data example is presented to illustrate the methods.The Canadian Journal of Statistics41: 453–465; 2013 © 2013 Statistical Society of Canada
Quantum Chemical Study of the Enzymatic Repair of T(6‐4)C/C(6‐4)T UV‐Photolesions by DNA Photolyases
Authors: Faraji Shirin , Wirz Lukas , Dreuw Andreas
Published: July 2013

Several strategies have evolved to repair one of the abundant UV radiation‐induced damages caused to DNA, namely the mutagenic pyrimidine (6‐4) pyrimidone photolesions. DNA (6‐4)‐photolyases are enzymes repairing these lesions by a photoinitiated electron transfer. An important aspect of a possible repair mechanism is its generality and transferability to different (6‐4) lesions. Therefore, previously suggested mechanisms for the repair of the T(6‐4)T lesion are here transferred to the T(6‐4)C and C(6‐4)T lesions and investigated theoretically using quantum chemical methods. Despite the different functional groups of the pyrimidine bases involved, a general valid molecular mechanism was identified, in which the initial step is an electron transfer coupled to a proton transfer from the protonated HIS365 to the N3′ nitrogen of the 3′ pyrimidine, followed by an intramolecular OH/NH2 transfer in one concerted step, which does not require an oxetane/azetidine or isolated water/ammonia intermediate.
Evaluation of the Structure–Activity Relationship of Rifabutin and Analogs: A Drug–Membrane Study
Authors: Pinheiro Marina , Pereira‐Leite Catarina , Arêde Mariana , Nunes Cláudia , Caio João M. , Moiteiro Cristina , Giner‐Casares Juan J. , Lúcio Marlene , Brezesinski Gerald , Camacho Luis , Reis Salette
Published: July 2013

This work focuses on the influence of rifabutin and two novel analogs, namely, N′‐acetyl‐rifabutin and N′‐butanoyl‐rifabutin, on the biophysical properties of lipid membranes. Monolayers and multilamellar vesicles composed of egg L‐α‐phosphatidylcholine:cholesterol in a molar ratio of 4:1 are chosen to mimic biological membranes. Several accurate biophysical techniques are used to establish a putative relationship between the chemical structure of the antimycobacterial compounds and their activity on the membranes. A combination of in situ experimental techniques, such as Langmuir isotherms, Brewster angle microscopy, polarization‐modulated infrared reflection–absorption spectroscopy, and small‐angle X‐ray scattering, is used to assess the drug–membrane interaction. A relationship between the effect of a drug on the organization of the membranes and their chemical structure is found and may be useful in the development of new drugs with higher efficacy and fewer toxic effects.
Exploiting the Twofold Donor Ability of Carbodiphosphoranes: Theoretical Studies of [(PPh3)2C→EH2]q (Eq=Be, B+, C2+, N3+, O4+) and Synthesis of the Dication [(Ph3P)2CCH2]2+
Authors: Celik Mehmet Ali , Frenking Gernot , Neumüller Bernhard , Petz Wolfgang
Published: July 2013

Quantum chemical calculations at the BP86/TZVPP//BP86/SVP level of theory have been performed for the isoelectronic series of compounds [(PPh3)2C→EH2]q (Eq=Be, B+, C2+, N3+, O4+). The equilibrium geometries and bond dissociation energies were calculated and the nature of the C→E bond was investigated with charge and energy decomposition methods. The dication [(PPh3)2C→CH2]2+ could become isolated as a salt compound with two counter ions [AlBr4]−. The X‐ray structure analysis of [(PPh3)2C→CH2]2+ gave bond lengths and angles that are in good agreement with the calculated data. The geometry optimization of [(PPh3)2C→OH2]4+ gave [(PPh3)2C→OH]3+ as the equilibrium structure. Bonding analysis of [(PPh3)2C→EH2]q shows that [(PPh3)2C→BeH2] and [(PPh3)2C→BH2]+ possess donor–acceptor bonds in which the σ and π lone‐pair electrons of (PPh3)2C donate into the vacant orbitals of the acceptor fragment. The multiply charged compounds are better described as substituted olefins [(PPh3)2CCH2]2+, [(PPh3)2CNH2]3+, and [(PPh3)2COH]3+, which possess electron‐sharing σ and π bonds that arise from the interaction between the triplet states of [(PPh3)2C]2+ and the respective fragment CH2, (NH2)+, and (OH)+. The multiply charged cations [(PPh3)2CCH2]2+, [(PPh3)2CNH2]3+, and [(PPh3)2COH]3+ are calculated to be stable toward dissociation.
Expression of insulin‐like growth factor binding proteins during mouse cochlear development
Authors: Okano Takayuki , Kelley Matthew W.
Published: June 2013

Background: Insulin‐like growth factor (IGF) signaling plays important roles in growth and cellular differentiation in the cochlear sensory epithelium. However, the roles of IGF binding proteins (IGFBPs), a family of IGF modulators, remain to be elucidated in this system. To begin to examine the role of IGFBPs, we used reverse transcription polymerase chain reaction (RT‐PCR) and in situ hybridization to determine the temporal and spatial patterns of expression for Igfbps within the developing mouse cochlea. Results: RT‐PCR analysis indicates that Igfpb2–5 are expressed in the cochlea between embryonic day (E) 13.5 and postnatal day (P) 0. In addition, the expression of each Igfbp significantly increased between E13.5 and P0. In situ hybridization indicates that Igfbp2, 3, 4, and 5 have distinct and complementary expression patterns in the developing cochlea. Moreover, expression patterns of Igfbp3 and 5 demonstrate contrasting gradients along the basal‐to‐apical axis of the cochlea. Conclusions: Igfbp2–5 are expressed in distinct and complementary patterns during cochlear development. These data suggest that IGFBPs may act to precisely regulate activation of IGF signaling in the developing cochlea in a cell type‐specific manner, contributing to cellular patterning and differentiation in the cochlea. Developmental Dynamics 242:1210–1221, 2013. © 2013 Wiley Periodicals, Inc.
Formation of the digestive tract in Ciona intestinalis includes two distinct morphogenic processes between its anterior and posterior parts
Authors: Nakazawa Keiichi , Yamazawa Takumi , Moriyama Yuuta , Ogura Yosuke , Kawai Narudo , Sasakura Yasunori , Saiga Hidetoshi
Published: June 2013

Background: In the ascidian Ciona intestinalis, the digestive tract, an essential system for animals, develops during metamorphosis from the two primordial tissues, the endoderm and endodermal strand, located in the larval trunk and tail, respectively. However, it has been largely unknown how the digestive tract develops from these primordial tissues. We examined the metamorphosing larvae for the tubular formation of the digestive tract, focusing on the epithelial organization of the endoderm, by combined confocal microscopy and computational rendering. Results: The tubular structure of the esophagus to the stomach was formed through the folding and closure of the endodermal epithelia in the central‐to‐right posterior trunk. By contrast, the intestine was formed in the left posterior trunk through the accumulation and rearrangement of the cells originated from the endodermal strand. This was confirmed by the cell‐tracing experiment using Kaede expression construct driven in the endodermal strand. Thus, the tubular formation of the digestive tract in C. intestinalis includes distinct morphogenetic processes and cell lineages between its anterior and posterior parts. Conclusion: This study provides the first detailed description of the digestive tract morphogenesis in C. intestinalis and serves as an important basis toward thorough understanding of its digestive tract development. Developmental Dynamics, 242:1172–1183, 2013. © 2013 Wiley Periodicals, Inc.
Recent colonization by a coastal plant of inland habitats at an ancient freshwater lake, Lake Biwa: multilocus sequencing and a demographic history of Lathyrus japonicus (Fabaceae)
Authors: Ohtsuki Tatsuo , Ikeda Hajime , Setoguchi Hiroaki
Published: July 2013

Ancient lakes have been recognized as “long‐term isolated islands” in terrestrial ecosystems. Lake Biwa, one of the few ancient lakes that formed around 4 million years ago, harbors many coastal species that commonly inhabit seashores. The beach pea, Lathyrus japonicus, is a typical coastal species of this freshwater lake, where morphological, physiological, and genetic differentiations have been reported between Biwa and coastal populations. Whether Biwa populations were isolated for long periods throughout Pleistocene climatic oscillations and subsequent range shifts is unclear. We assessed population genetic structure and demography of beach pea in this ancient freshwater lake using the sequences of eight nuclear loci. The results of STRUCTURE analyses showed evidence of admixture between Biwa and coastal populations, reflecting recent gene flow. The estimated demographic parameters implemented by the isolation with migration model (IM model) revealed a recent divergence (postglacial period) of Biwa populations, with some gene flow from Biwa to coastal populations. In addition, Biwa populations were significantly smaller in size than the ancestral or coastal populations. Our study suggests that a Holocene thermal maximum, when transgression could allow seeds from coastal plants to access Lake Biwa, was involved in the origin of the Biwa populations and their genetic divergence. Thus, coastal populations might have migrated to Lake Biwa relatively recently. Our study concluded that ancestral migrants in Lake Biwa were derived from small founding populations and accelerated genetic isolation of Biwa populations during short‐term isolation.
Evidence of gene flow between sympatric populations of the Middle East‐Asia Minor 1 and Mediterranean putative species of Bemisia tabaci
Authors: Tahiri Abdessalem , Halkett Fabien , Granier Martine , Gueguen Gwénaelle , Peterschmitt Michel
Published: July 2013

Bemisia tabaci is a complex of putative species that exhibit a strong geographical pattern. Crossing experiments have revealed various degrees of reproductive isolation between these nascent species, ranging between fertile first‐generation hybrids (F1) and no F1 at all. However, the relevance of these results under natural conditions is generally not known. The worldwide invasion of the putative species Middle East‐Asia Minor 1 (MEAM1) has caused secondary contacts between allopatric species, which in turn provide an opportunity to detect potential hybrids in nature. A total of 346 female B. tabaci were collected in 2003 and 2005 in the North East of Morocco and assigned to MEAM1 (119), Mediterranean (Med) (225) and a new putative species (2) using mitochondrial cytochrome oxidase (mtCOI) gene sequences. MEAM1 and Med individuals were characterized at seven microsatellite loci. MEAM1 and Med were found to be sympatric in 11 of 12 samples (6 fields/year). As previously reported from Spain, MEAM1 frequency decreased over time. The genetic data are consistent with a recent introduction of MEAM1. A Bayesian clustering analysis (Structure) distinguished two groups, which were 100% consistent with the mtCOI groups. From several lines of evidence, two individuals were identified as hybrids. Assignment profiles using NewHybrids and allele composition indicated that they were not F1 hybrids. The results are discussed in relation to the secondary endosymbiont infection status determined on a sample of individuals, and the contrasting outcomes of the reported crossing experiments between MEAM1 and Med.
Investigating sex‐specific dynamics using uniparental markers: West New Guinea as a case study
Authors: Mona Stefano , Mordret Ernest , Veuille Michel , Tommaseo‐Ponzetta Mila
Published: July 2013

MitochondrialDNA(mtDNA) andYchromosome (NRY) genetic markers have been often contrasted to investigate sex‐specific dynamics. Traditionally, isolation by distance, intrapopulation genetic diversity and population differentiation are estimated from both markers and compared. Two possible sources of bias are often neglected. First, kilometric distances are frequently used as predictor of the connectivity between groups, hiding the role played by environmental features at a microgeographic scale. Second, the comparison of intrapopulation diversity and population differentiation between mtDNAandNRYis hampered by their different mutational mechanisms and rates. Here, we show how to account for these biases by analyzing from a different perspective a published dataset of eightWestNewGuinea (WNG) populations for which mtDNAcontrol region sequences and seven linkedNRYmicrosatellites had been typed. First, we modeled the connectivity among sampled populations by computing the number of days required to travel between groups. Then, we investigated the differences between the two sexes accounting for the molecular characteristics of the markers examined to obtain estimates on the product of the effective population size and the migration rate among demes (Nm). We achieved this goal by studying the shape of the gene genealogy at several sampling levels and using spatial explicit simulations. Both the direction and the rate of migration differ between male and females, with anNmestimated to be >6 times higher in the latter under many evolutionary scenarios. We finally highlight the importance of applying metapopulation models when analyzing the genetic diversity of a species.
Long‐Range Diastereoselectivity in an Ugi Reaction: Stereocontrolled and Diversity‐Oriented Synthesis of Tetrahydrobenzoxazepines
Authors: Banfi Luca , Bagno Alessandro , Basso Andrea , De Santis Carlo , Riva Renata , Rastrelli Federico
Published: July 2013

Salicylaldehydes and protected 1,2‐amino alcohols have been convergently converted into a series of 2,3‐dihydrobenzo[f][1,4]oxazepines, which undergo an Ugi–Joullié multicomponent reaction with unusual long‐range diastereoselectivity. This protocol allows the diastereoselective preparation, in only two steps, of a series of drug‐like tetrahydrobenzo[f][1,4]oxazepines, with the combinatorial introduction of four diversity points. The possibility of obtaining these compounds in enantiomerically pure form was also demonstrated.
Laughing and liking: Exploring the interpersonal effects of humor use in initial social interactions
Authors: Treger Stanislav , Sprecher Susan , Erber Ralph
Published: July 2013

Humor is a common interpersonal phenomenon that may positively influence the trajectories of social interactions. In two social interaction experiments, we examined the association between humor and liking. The first study was a secondary analysis of data from a prior experiment (originally conducted for another purpose) in which unacquainted participants engaged in a self‐disclosure task and rated each other on various dimensions, including humor. In Experiment 2, unacquainted mixed‐sex dyads participated in a series of either humorous or similar but non‐humorous tasks. In both studies, humor was positively associated with liking and closeness; perceived reciprocal liking and enjoyment of the interaction mediated the association between humor and liking. Likewise, we found a positive association between liking and humor. Men and women did not differ in self‐reported humor use. The findings suggest that humor is a mechanism used to establish connections with others across all relationships and for both sexes. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of CO2 stripping on pH in open‐recirculating cooling water systems
Authors: Safari Iman , Hsieh Ming‐Kai , Chien Shih‐Hsiang , Walker Michael E. , Vidic Radisav D. , Dzombak David A. , Abbasian Javad
Published: June 2013

A simplified mathematical model has been developed to evaluate the effect of CO2 stripping on pH of recirculating cooling water in power plant cooling systems. Experimental data from three pilot‐scale cooling towers using treated municipal wastewater as makeup water were used to determine the CO2 mass transfer coefficients in the gas phase kg and aqueous phase kw. The optimum values of the gas film mass transfer coefficient and water film mass transfer coefficient were determined by regression to be kg = 8.4 × 10−6 m/s and kw=8.4 × 10−8m/s, respectively. The results also indicate that the model is capable of predicting the pH of the cooling loop as a function of makeup water alkalinity and cooling loop alkalinity (in case of salt formation) as well as the operating parameters of the cooling system. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 275–282, 2014
On the potential role of marine calcifiers in glacial‐interglacial dynamics
Authors: Omta Anne Willem , K. van Voorn George A. , M. Rickaby Rosalind E. , Follows Michael J.
Published: June 2013

Ice core measurements have revealed a highly asymmetric cycle in Antarctic temperature and atmospheric CO2 over the last 800 kyr. Both CO2 and temperature decrease over 100 kyr going into a glacial period and then rise steeply over less than 10 kyr at the end of a glacial period. There does not yet exist wide agreement about the causes of this cycle or about the origin of its shape. Here we explore the possibility that an ecologically driven oscillator plays a role in the dynamics. A conceptual model describing the interaction between calcifying plankton and ocean alkalinity shows interesting features: (i) It generates an oscillation in atmospheric CO2 with the characteristic asymmetric shape observed in the ice core record, (ii) the system can transform a sinusoidal Milankovitch forcing into a sawtooth‐shaped output, and (iii) there are spikes of enhanced calcifier productivity at the glacial‐interglacial transitions, consistent with several sedimentary records. This suggests that ecological processes might play an active role in the observed glacial‐interglacial cycles.
Tectonic uplift mechanism of the Goodenough and Fergusson Island gneiss domes, eastern Papua New Guinea: Constraints from seismic reflection and well data
Authors: Fitz Guy , Mann Paul
Published: June 2013

The D'Entrecasteaux Island (DEI) gneiss domes are fault‐bounded domes with ∼2.5 km of relief exposing ultrahigh‐pressure (UHP) and high‐pressure (HP) metamorphic gneisses and migmatites exhumed in an Oligocene‐Miocene arc‐continent collision and subduction zone subject to Late Miocene to Recent continental extension. To study the style of continental extension accompanying exhumation of the DEI gneiss domes, a grid of 1518 km of 2‐D multichannel seismic (MCS) reflection data and well data is interpreted from the offshore areas surrounding the DEI, including the Trobriand basin and the Goodenough basin. The offshore study is combined with onshore geologic information to constrain the Oligocene to Recent tectonic evolution of the basins. MCS and well data are consistent with the Trobriand basin forming as a forearc basin caused by southward Miocene subduction at the Trobriand trench. At ∼8 Ma, the margin transitioned to an extensional tectonic environment. Since then, the Trobriand basin has subsided 1–2.5 km with few normal faults deforming the basin fill. South of the DEI, the Goodenough rift basin developed after extension began (∼8 Ma) with the hanging wall of the north‐dipping Owen‐Stanley normal fault bounding the southern margin of the basin. The lack of evidence of upper crustal extension accompanying subsidence in the Trobriand and Goodenough basins suggests depth‐dependent lithospheric extension from 8 to 0 Ma has accompanied uplift of the DEI gneiss domes and supports schematic model of uplift of the DEI domes involving vertical exhumation of buoyant, postorogenic lower crust, far‐field extension from slab rollback, and an inverted two‐layer crustal density structure.
Crustal structure along the Aleutian island arc: New insights from receiver functions constrained by active‐source data
Authors: Janiszewski Helen A. , Abers Geoffrey A. , Shillington Donna J. , Calkins Josh A.
Published: June 2013

Key Points

Aleutian crustal structure determined through receiver functions

Active source results constrain receiver function data using new method

Parameters describing magma chamber estimated through forward modeling
Electrical conductivity of the Pampean shallow subduction region of Argentina near 33 S: Evidence for a slab window
Authors: Burd Aurora I. , Booker John R. , Mackie Randall , Pomposiello Cristina , Favetto Alicia
Published: June 2013

We present a three‐dimensional (3‐D) interpretation of 117 long period (20–4096 s) magnetotelluric (MT) sites between 31°S and 35°S in western Argentina. They cover the most horizontal part of the Pampean shallow angle subduction of the Nazca Plate and extend south into the more steeply dipping region. Sixty‐two 3‐D inversions using various smoothing parameters and data misfit goals were done with a nonlinear conjugate gradient (NLCG) algorithm. A dominant feature of the mantle structure east of the horizontal slab is a conductive plume rising from near the top of the mantle transition zone at 410 km to the probable base of the lithosphere at 100 km depth. The subducted slab is known to descend to 190 km just west of the plume, but the Wadati‐Benioff zone cannot be traced deeper. If the slab is extrapolated downdip it slices through the plume at 250 km depth. Removal of portions of the plume or blocking vertical current flow at 250 km depth significantly changes the predicted responses. This argues that the plume is not an artifact and that it is continuous. The simplest explanation is that there is a “wedge”‐shaped slab window that has torn laterally and opens down to the east with its apex at the plume location. Stress within the slab and seismic tomography support this shape. Its northern edge likely explains why there is no deep seismicity south of 29°S.
Dependence of abrupt Atlantic meridional ocean circulation changes on climate background states
Authors: Gong Xun , Knorr Gregor , Lohmann Gerrit , Zhang Xu
Published: June 2013

Abrupt decadal climate changes during the last glacial‐interglacial cycle are less pronounced during maximum glacial conditions and absent during the Holocene. To further understand the underlying dynamics, we conduct hosing experiments for three climate states: preindustrial (PI), 32 kiloannum before present (ka B.P.), and Last Glacial Maximum (LGM). Our simulations show that a stronger temperature inversion between the surface and intermediate layer in the South Labrador Sea induces a faster restart of convective processes (32 ka B.P. > LGM > PI) during the initial resumption of the Atlantic meridional overturning circulation (AMOC). A few decades later, an AMOC overshoot is mainly linked to the advection of warmer and saltier intermediate‐layer water from the tropical Atlantic into the South Labrador Sea, which causes a stronger deep‐water formation than that before the freshwater perturbation. This mechanism is most pronounced during the 32 ka B.P., weaker during the LGM and absent during the PI.
Perceiving nonverbal behavior: Neural correlates of processing movement fluency and contingency in dyadic interactions
Authors: Georgescu Alexandra L. , Kuzmanovic Bojana , Santos Natacha S. , Tepest Ralf , Bente Gary , Tittgemeyer Marc , Vogeley Kai
Published: June 2013

Despite the fact that nonverbal dyadic social interactions are abundant in the environment, the neural mechanisms underlying their processing are not yet fully understood. Research in the field of social neuroscience has suggested that two neural networks appear to be involved in social understanding: (1) the action observation network (AON) and (2) the social neural network (SNN). The aim of this study was to determine the differential contributions of the AON and the SNN to the processing of nonverbal behavior as observed in dyadic social interactions. To this end, we used short computer animation sequences displaying dyadic social interactions between two virtual characters and systematically manipulated two key features of movement activity, which are known to influence the perception of meaning in nonverbal stimuli: (1) movement fluency and (2) contingency of movement patterns. A group of 21 male participants rated the “naturalness” of the observed scenes on a four‐point scale while undergoing fMRI. Behavioral results showed that both fluency and contingency significantly influenced the “naturalness” experience of the presented animations. Neurally, the AON was preferentially engaged when processing contingent movement patterns, but did not discriminate between different degrees of movement fluency. In contrast, regions of the SNN were engaged more strongly when observing dyads with disturbed movement fluency. In conclusion, while the AON is involved in the general processing of contingent social actions, irrespective of their kinematic properties, the SNN is preferentially recruited when atypical kinematic properties prompt inferences about the agents' intentions. Hum Brain Mapp 35:1362–1378, 2014. © 2013 Wiley Periodicals, Inc.