bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetotransport Properties and Kondo Effect Observed in a Ferromagnetic Single‐Crystalline Fe1−xCoxSi Nanowire
Authors: Lee Sunghun , In Juneho , Chang Jung‐Won , Seo Kwanyong , Jung Myung‐Hwa , Kim Jinhee , Kim Bongsoo
Published: December 2011

We report unconventional magnetotransport properties of an individual Fe1−xCoxSi nanowire. We have studied the dependence of the resistivity on the angle between the directions of the magnetization and electrical current below the Curie temperature (TC). The observed anisotropic magnetoresistance (MR) ratio is negative, thereby indicating that the conduction electrons in a minority spin band of the Fe1−xCoxSi nanowire dominantly contribute to the transport. Unlike typical ferromagnets, positive MR is observed in the overall temperature range. MR curves are linear below TC and show a quadratic form above TC, which can be explained by the change of density of states that arises as the band structures of the Fe1−xCoxSi nanowire shift under a magnetic field. The temperature dependence of the resistivity curve is sufficiently explained by the Kondo effect. The Kondo temperature of the Fe1−xCoxSi nanowire is lower than that of the bulk state due to suppression of the Kondo effect. The high single crystallinity of Fe1−xCoxSi nanowires allowed us to observe and interpret quite subtle variations in the prominent intrinsic transport properties.
Nanoporous Carbon Materials for Electrochemical Sensing
Authors: Poh Hwee Ling , Pumera Martin
Published: December 2011

Nanoporous carbon materials are highly important materials for a wide array of applications. Here we show that nanoporous carbon can act as highly active materials for electrochemical sensing. We observed that nanoporous carbon material exhibits a faster heterogeneous electron transfer than graphite and pure carbon nanotubes. Nanoporous carbon exhibits a superior electrochemical performance for sensing of important biomarkers such as dopamine, ascorbic acid, uric acid, NADH, DNA bases, and forensic‐related compounds such as nitroaromatic explosives.
Reaction of Acetals with Various Carbon Nucleophiles under Non‐Acidic Conditions: CC Bond Formation via a Pyridinium‐Type Salt
Authors: Fujioka Hiromichi , Yahata Kenzo , Hamada Tomohito , Kubo Ozora , Okitsu Takashi , Sawama Yoshinari , Ohnaka Takuya , Maegawa Tomohiro , Kita Yasuyuki
Published: December 2011

Mild substitution reactions of acetals with carbon nucleophiles via the pyridinium‐type salts generated by the treatment of acetals with TESOTf‐2,4,6‐collidine or 2,2′‐bipyridyl have been developed. Various carbon nucleophiles, such as organocuprates, silyl enol ethers, enamines, etc., reacted with the pyridinium‐type salts to give the corresponding substituted products in good yields. The reactions proceeded under very mild conditions (non‐acidic conditions) and thus acid‐sensitive functional groups can be tolerated during the reaction. In addition, only an acetal can form the pyridinium‐type salt and react with nucleophiles in the presence of a ketal. This unusual selectivity is in contrast to general methods conducted under acidic conditions.
Identification of NWP humidity biases using high‐peaking water vapour channels from IASI
Authors: Hilton F. I. , Newman S. M. , Collard A. D.
Published: December 2011

High‐peaking water vapour channels from the Infrared Atmospheric Sounding Interferometer (IASI) have been used to diagnose biases in the Met Office short‐range forecasts of upper tropospheric humidity during the Joint Airborne IASI Validation Experiment (JAIVEx) field campaign. These biases are compared with those from the European Centre for Medium‐Range Weather Forecasts (ECMWF). The Met Office forecasts are found to be too dry relative to IASI observations and in comparison with ECMWF forecasts globally. IASI is shown to be a useful tool for investigating such biases, and subsequent changes to the Met Office data assimilation scheme have successfully reduced this forecast bias. © 2011 Royal Meteorological Society and British Crown copyright, the Met Office
Results of magnetic field observations of stars with helium anomalies with the 6‐m telescope
Authors: Yakunin I. , Romanyuk I. , Kudryavtsev D. , Semenko E.
Published: December 2011

We present new longitudinal magnetic field observations of hot CP stars with helium anomalies obtained on 6‐m telescope at years 2010 and 2011. The survey includes more than 30 objects. For 8 stars magnetic field was detected for the first time. For 2 previously known magnetic stars HD 36485 and HD 35298 circular polarized spectra were obtained at different phases of the period. Both stars show lines with non‐usual complicated distribution of Stokes V which is changing strongly during their rotation (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Speckle interferometry of magnetic Ap/Bp stars at the BTA 6‐m telescope (new binary and multiple systems)
Authors: Balega Y.Y. , Dyachenko V.V. , Maksimov A.F. , Malogolovets E.V. , Rastegaev D.A. , Romanyuk I.I.
Published: December 2011

We report the results of speckle interferometric observations of 117 Ap/Bp stars made with the 6‐m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences in December 2009. We resolved 27 binary and 2 triple stars into individual components. Fourteen of these stars were astrometrically resolved for the first time. The fraction of speckle interferometric binaries in the sample of 117 Ap/Bp stars with confirmed magnetic fields is 25%. We expect that the total fraction of binaries in the sample with account for spectroscopic short‐period systems and astrometric common proper motion pairs can be twice higher (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Statistics of magnetic fields and fluxes of massive OB stars and the origin of neutron star magnetic fields
Authors: Igoshev A.P. , Kholtygin A.F.
Published: December 2011

Based on the newest measurements, statistical properties of rms mean magnetic fields of OB and neutron stars (NSs) were investigated. The magnetic field distribution function f (B) for OB stars was determined and a sharp decrease of f (B) for weak magnetic fields was found. The mean magnetic fluxes F for all massive stars and NSs with measured magnetic fields was estimated, and it was found that log F = 27.7 for OB stars and log F = 24.5 for NSs. To explain the large differences of the fluxes from normal and neutron stars we studied the birth and evolution of isolated neutron stars in the whole volume of our Galaxy with our new code of population synthesis. We started modeling the birth of massive OB stars and followed their motion within the spiral arms to the point of supernova explosion. Next we considered the evolution of NS up to the death line with considering the magnetic field decay. We found that a significant magnetic field decay occurs during the first million years of a NS's life. We have estimated the mean time of the Ohmic decay for NS. We modeled the distributions of pulsar periods P, of period derivatives $ \dot P $, and of pulsar magnetic fields B, and found that they are in a good agreement with those taken from ATNF Pulsar Catalogue (Manchester et al. 2005) (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of stratification in spherical shell convection
Authors: Käpylä P.J. , Mantere M.J. , Brandenburg A.
Published: December 2011

We report on simulations of mildly turbulent convection in spherical wedge geometry with varying density stratification. We vary the density contrast within the convection zone by a factor of 20 and study the influence of rotation on the solutions. We demonstrate that the size of convective cells decreases and the anisotropy of turbulence increases as the stratification is increased. Differential rotation is found to change from anti‐solar (slow equator) to solar‐like (fast equator) at roughly the same Coriolis number for all stratifications. The largest stratification runs, however, are sensitive to changes of the Reynolds number. Evidence for a near‐surface shear layer is found in runs with strong stratification and large Reynolds numbers (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Shock formation around planets orbiting M‐dwarf stars
Authors: Vidotto A.A. , Llama J. , Jardine M. , Helling Ch. , Wood K.
Published: December 2011

Bow shocks can be formed around planets due to their interaction with the coronal medium of the host stars. The net velocity of the particles impacting on the planet determines the orientation of the shock. At the Earth's orbit, the (mainly radial) solar wind is primarily responsible for the formation of a shock facing towards the Sun. However, for close‐in planets that possess high Keplerian velocities and are frequently located at regions where the host star's wind is still accelerating, a shock may develop ahead of the planet. If the compressed material is able to absorb stellar radiation, then the signature of bow shocks may be observed during transits. Bow‐shock models have been investigated in a series of papers (Llama et al. 2011; Vidotto et al. 2010, 2011a,b) for known transiting systems. Once the signature of a bow‐shock is observed, one can infer the magnetic field intensity of the transiting planet. Here, we investigate the potential to use this model to detect magnetic fields of (hypothetical) planets orbiting inside the habitable zone of M‐dwarf stars. For these cases, we show, by means of radiative transfer simulations, that the detection of bow‐shocks of planets surrounding M‐dwarf stars may be more difficult than for the case of close‐in giant planets orbiting solar‐type stars (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of turbulent pumping on stellar activity cycles
Authors: Do Cao O. , Brun A.S.
Published: December 2011

Stellar magnetic activity of solar like stars is thought tobe due to an internal dynamo. While the Sun has been the subject of intense research for refining dynamo models, observations of magnetic cyclic activity in solar type stars have become more and more available, opening a new path to understand the underlying physics behind stellar cycles. For instance, it is key to understand how stellar rotation rate influences magnetic cycle period Pcyc. Recent numerical simulations of advection‐dominated Babcock Leighton models have demonstrated that it is difficult to explain this observed trend given a) the strong influence of the cycle period to the meridional circulation amplitude and b) the fact that 3D models indicate that meridional flows become weaker as the rotation rate increases. In this paper, we introduce the turbulent pumping mechanism as another advective process capable also of transporting the magnetic fields. We found that this model is now able to reproduce the observations under the assumption that this effect increases as Ω2. The turbulent pumping becomes indeed another major player able to circumvent the meridional circulation. However, for high rotation rates (Ω ≃ 5Ω⊙), its effects dominate those of the meridional circulation, entering a new class of regime dominated by the advection of turbulent pumping and thus leading to a cyclic activity qualitatively different from that of the Sun (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flow injection chemiluminescence determination of vitamin B12 using on‐line UV‐persulfate photooxidation and charge coupled device detection
Authors: Murillo Pulgarín José A. , García Bermejo Luisa F. , Nieves Sánchez García M.
Published: December 2011

A sensitive chemiluminescence method for vitamin B12 using a charge‐coupled device (CCD) photodetector combined with on‐line UV‐persulfate oxidation in a simple continuous flow system has been developed. The principle for the determination of vitamin B12 is based on the enhancive effect of cobalt (II) on the chemiluminescence reaction between luminol and percarbonate in alkaline medium. In addition, percarbonate has been investigated and proposed as a powerful source of hydrogen peroxide as oxidant agent in this chemiluminescence reaction. The digestion of vitamin B12 to release the cobalt (II) is reached by UV irradiation treatment in a persulfate medium. The CCD detector, directly connected to the flow cell, is used with the continuous flow manifold to obtain the full spectral characteristics of cobalt (II) catalyzed luminol–percarbonate reaction. The vitamin B12 oxidation process and chemical conditions for the chemiluminescence reaction were investigated and optimized. The increment of the emission intensity was proportional to the concentration of vitamin B12, giving a second‐order calibration graph over the cobalt (II) concentration range from 10 to 5000 μg L−1 (r2 = 0.9985) with a detection limit of 9.3 μg L−1. The proposed method was applied to the determination of vitamin B12 in different kinds of pharmaceuticals. Copyright © 2011 John Wiley & Sons, Ltd.
Bioluminescent enzyme assay for the indication of plant stress in enclosed life support systems
Authors: Kratasyuk Valentina , Esimbekova Elena , Correll Melanie , Bucklin Ray
Published: December 2011

The application of bioluminescent sensors for monitoring key metabolites and enzymes that are indicators of stress in plants is demonstrated. The sensitivity of bioluminescent assay for NAD(P)H and NAD(P)+ was about 0.5 and 1 nmol, respectively. The levels of NAD(P)H and NAD(P)+ in radish (Raphanus sativus) root extracts from controls and from stress‐induced conditions were compared. To induce environmental stress, the plants were grown in enclosed environmental chambers with low pressure (9 or 32 kPa), high humidity (>80%) and low oxygen partial pressure (down to 3.3–6.5 kPa). The concentrations of NAD(P)+ and NAD(P)H in plants varied under stress conditions. Decreasing both total pressure from 101.5 to 32 or 9 kPa and partial pressure of oxygen increased the ratio of NAD(P)+/NAD(P)H from 0.2 to 4 or 6, respectively. The increase in this ratio suggests that plants are undergoing stress in these hypobaric environments. The developed bioluminescent assay for quantification of pyridine nucleotides in plant tissues is rapid, low‐cost and easily performed. Copyright © 2011 John Wiley & Sons, Ltd.
Immobilization of lipase B from Candida antarctica on porous styrene–divinylbenzene beads improves butyl acetate synthesis
Authors: Graebin Natália G. , Martins Andréa B. , Lorenzoni André S. G. , Garcia‐Galan Cristina , Fernandez‐Lafuente Roberto , Ayub Marco A. Z. , Rodrigues Rafael C.
Published: December 2011

A new biocatalyst of lipase B from Candida antarctica (MCI‐CALB) immobilized on styrene–divinylbenzene beads (MCI GEL CHP20P) was compared with the commercial Novozym 435 (immobilized lipase) in terms of their performances as biocatalysts for the esterification of acetic acid and n‐butanol. The effects of experimental conditions on reaction rates differed for each biocatalyst, showing different optimal values for water content, temperature, and substrate molar ratio. MCI‐CALB could be used at higher acid concentrations, up to 0.5 M, while Novozym 435 became inactivated at these acid concentrations. Although Novozym 435 exhibited 30% higher initial activity than MCI‐CALB for the butyl acetate synthesis, the reaction course was much more linear using the new preparation, meaning that the MCI‐CALB allows for higher productivities per cycle. Both preparations produced around 90% of yield conversions after only 2 h of reaction, using 10% (mass fraction) of enzyme. However, the main advantage of the new biocatalyst was the superior performance during reuse. While Novozym 435 was fully inactivated after only two batches, MCI‐CALB could be reused for six consecutive cycles without any washings and keeping around 70% of its initial activity. It is proposed that this effect is due to the higher hydrophobicity of the new support, which does not retain water or acid in the enzyme environment. MCI‐CALB has shown to be a very promising biocatalyst for the esterification of small‐molecule acids and alcohols. © 2012 American Institute of Chemical Engineers Biotechnol. Prog.,, 2012
Enzymatic Recognition of 2′‐Modified Ribonucleoside 5′‐Triphosphates: Towards the Evolution of Versatile Aptamers
Authors: Lauridsen Lasse H. , Rothnagel Joseph A. , Veedu Rakesh N.
Published: December 2011

The quest for effective, selective and nontoxic nucleic‐acid‐based drugs has led to designing modifications of naturally occurring nucleosides. A number of modified nucleic acids have been made in the past decades in the hope that they would prove useful in target‐validation studies and therapeutic applications involving antisense, RNAi, aptamer, and ribozyme‐based technologies. Since their invention in the early 1990s, aptamers have emerged as a very promising class of therapeutics, with one drug entering the market for the treatment of age‐related macular degeneration. To combat the limitations of aptamers containing naturally occurring nucleotides, chemically modified nucleotides have to be used. In order to apply modified nucleotides in aptamer drug development, their enzyme‐recognition capabilities must be understood. For this purpose, several modified nucleoside 5′‐triphosphates were synthesized and investigated as substrates for various enzymes. Herein, we review studies on the enzyme‐recognition of various 2′‐sugar‐modified NTPs that were carried out with a view to their effective utilization in SELEX processes to generate versatile aptamers.
Novel Cell‐Penetrating Peptides Based on α‐Aminoxy Acids
Authors: Ma Yilong , Yang Dongmei , Ma Yan , Zhang Yu‐Hui
Published: December 2011

The remarkable ability of cell‐penetrating peptides (CPPs) to deliver cell‐impermeable compounds into living cells makes them attractive transporters for use in biology and medicine. Despite their highly efficient cellular uptake, CPPs consisting of natural amino acids always suffer from degradation and endosomal entrapment, thereby greatly limiting their application in vivo. Here, we describe the preparation of novel CPPs incorporating α‐aminoxy acid residues and their cellular uptake behavior. We demonstrate that introducing α‐aminoxy acids into the backbones of CPPs enhances their diffuse cytosolic distribution after direct membrane translocation. We also reveal a hybrid peptide, consisting of D‐α‐aminoxy acids and L‐α‐amino acids, that achieves efficient diffuse distribution in the cytosol, is stable toward serum, and possesses low cytotoxicity, thus making it a possible vector candidate for in vivo applications. Our results confirm that α‐aminoxy acids are useful building blocks when designing novel CPPs possessing favorable properties.
On the Role of Residual Ag in Nanoporous Au Catalysts for CO Oxidation: A Combined Microreactor and TAP Reactor Study
Authors: Wang L. C. , Zhong Y. , Widmann D. , Weissmüller J. , Behm R. J.
Published: December 2011

The influence of residual Ag on the formation of stable adsorbed active oxygen species (oxygen storage capacity, OSC) and its correlation with the activity and stability in the CO oxidation reaction on nanoporous gold (NPG) was investigated by a combination of kinetic and temporal analyses of products (TAP) reactor measurements, comparing four different NPG samples with different Ag contents. The data demonstrated that oxygen can be activated and stored on the NPG catalysts at room temperature. Clearly the surface Ag content influenced both the OSC and activity, with a more qualitative correlation for the fresh catalysts and an approximately linear relationship for the stable catalysts after 1000 min on stream. A strictly linear correlation between catalytic activity and OSC, both before and after the reaction, indicated that the active oxygen detected by the TAP reactor measurements also represents the active oxygen species for the reaction at atmospheric pressure. Consequences for the mechanistic understanding of the CO oxidation reaction on NPG catalysts are discussed.
Donor–Acceptor Ring‐in‐Ring Complexes
Authors: Forgan Ross S. , Wang Cheng , Friedman Douglas C. , Spruell Jason M. , Stern Charlotte L. , Sarjeant Amy A. , Cao Dennis , Stoddart J. Fraser
Published: December 2011

The self‐assembly of three donor–acceptor ring‐in‐ring complexes, prepared from the π‐electron‐deficient tetracationic cyclophane, cyclobis(paraquat‐4,4′‐biphenylene), and three large π‐electron‐rich crown ethers (each 50‐membered rings) containing dioxynaphthalene (DNP) and tetrathiafulvalene (TTF) units in pairs (DNP/DNP, DNP/TTF and TTF/TTF), is reported. 1H NMR spectroscopic analyses are indicative of the formation of 1:1 complexes in CD3CN, whilst the charge‐transfer interactions between the DNP and TTF units of the crown ethers and the tetracationic cyclophane have permitted the measurement of binding constants of up to 4×103 M−1 in CH3CN to be made using UV/Vis spectroscopy. Ring‐in‐ring complexes are proposed as intermediates in the stepwise synthesis of molecular Borromean rings (BRs) comprised of three different rings. With the particular choice of crown ethers, the 1:1 complexes have polyether loops that protrude from the donor–acceptor recognition point above and below the mean plane of the tetracationic cyclophane, which, ideally, could conceivably bind dialkylammonium centers present in a third ring. X‐ray crystallographic analyses of the solid‐state superstructures of two of the three 1:1 complexes reveal, however, the presence of prodigious CH⋅⋅⋅O interactions between the polyether loops of the crown ethers and the rims of the cyclophane, no doubt stabilizing the complexes, but, at the same time, masking their potential recognition sites from further interactions that are essential to the subsequent emergence of the third ring. The solid‐state superstructure of one of the crown ethers binding two dibenzylammonium ions provides some insight into the design requirements for the next generation of these systems; longer polyether loops may be required to allow optimal interactions between all components. It has become clear during a pursuit of the stepwise synthesis of the molecular BRs that, when designing complex mechanically interlocked molecules utilizing multiple recognition sites, the unsullied orthogonality of the recognition motifs is of the utmost importance.
Adsorption–Reduction Behavior of Co(NH3) on Activated Carbon
Authors: Mao Yan‐Peng , Chen Yu , Cheng Jing‐Yi , Zhu Hai‐Song , Long Xiang‐Li , Yuan Wei‐Kang
Published: December 2011

A novel method has been put forward to retrofit the wet ammonia desulfurization process to realize the combined removal of sulfur dioxide and nitric oxide by introducing soluble cobalt(II) salt into aqueous ammonia solution. The active constituent of scrubbing NO from the flue gases is the ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 2 + }} $ produced by ammonia coordinating with Co2+. The regeneration of ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 2 + }} $ can be realized under the catalysis of activated carbon so as to sustain a high NO removal efficiency for a long time. In this paper, the adsorption–reduction behavior of ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 3 + }} $ on activated carbon has been researched using scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. A conclusion can be drawn from the results that cobalt ions in the aqueous solution are adsorbed by activated carbon and most of them are reduced to Co2+ ions, and some of the Co2+ ions are further reduced into metallic cobalt. The results also demonstrate that the functional groups on the surface of carbon take part in this redox reaction. The CH groups on the carbon surface are oxidized into COH, and then some of the hydroxyl groups are further oxidized into carbonyl or carboxyl groups.
Treating Leather Tanning Wastewater with Stone Cutting Solid Waste
Authors: Al‐Jabari Maher , Abualfailat Malek , Shaheen Safa
Published: December 2011

This paper presents a new environmental approach for reducing environmental impacts of two local Palestinian industries: It implements the principle of “treating waste by waste.” The technical feasibility of chromium removal from wastewater in leather making by its treatment with solid waste from stone cutting industry is demonstrated experimentally, and found to be an efficient approach. Nearly full removal of chromium is obtained at optimum operating conditions using sufficient mass of solid waste (limestone) and allowing enough contact time between the two wastes. This study investigated effects of various parameters on the percentage relative decrease in concentration by using ultra violet (UV)/Vis spectrophotometry. Kinetic curves showed that percentage relative decrease in concentration increased with time until approaching a plateau (adsorption capacity). The adsorption capacity increased with increasing limestone to liquid ratio (solid content), until nearly full removal of chromium was obtained when the solid content was 5 g/100 mL or higher. This was accomplished within few days when the particles were settled. The adsorption capacity was pH dependent; adsorption at pH < 5 was obtained, as a finding which was not reported by previous investigators for Cr(III) adsorption using other particles. The percentage removal was nearly doubled at higher pH values (>5). Further research work is proposed to distinguish between the contributions of the two removal mechanisms of precipitation and adsorption.
Cognitive functioning after cancer treatment
Authors: Phillips Kristin M. , Jim Heather S. , Small Brent J. , Laronga Christine , Andrykowski Michael A. , Jacobsen Paul B.
Published: December 2011

BACKGROUND:

This study examined the influence of prior treatment on the course of cognitive functioning in breast cancer survivors. Changes in cognitive functioning over time were compared in breast cancer survivors treated with chemotherapy plus radiotherapy, breast cancer survivors treated with radiotherapy only, and women with no history of cancer.

METHODS:

Stage 0‐II breast cancer patients treated with chemotherapy plus radiotherapy (CT group; n = 62) or radiotherapy only (RT group; n = 67) completed neuropsychological assessments 6 months after completing treatment and again 36 months later. Women with no history of cancer (NC group; n = 184) were assessed over a similar interval.

RESULTS:

A significant group × time effect was found for processing speed (P = .009) that reflected a tendency for the NC group but not the RT and CT groups to improve over time. There was also a significant group effect for executive functioning (P = .006) that reflected the NC group performing better than the CT and RT groups. Additional analyses found the administration of hormonal therapy was not associated with change over time in cognitive performance.

CONCLUSIONS:

Findings provide limited support for the view that changes in cognitive functioning in cancer survivors are attributable to chemotherapy administration and illustrate the importance of including a radiotherapy comparison group. Future research should seek to examine possible mechanisms that could explain the apparent prolonged impact of both chemotherapy and radiotherapy on cognitive functioning in breast cancer survivors. Cancer 2012;. © 2011 American Cancer Society.
A DFT Study of the Interaction between Microhydrated Anions and Naphthalendiimides
Authors: Campo‐Cacharrón Alba , Cabaleiro‐Lago Enrique M. , Rodríguez‐Otero Jesús
Published: December 2011

The characteristics of the interaction of anions with naphthalendiimides, the basic structural motif of a newly synthesized anion channel based on anion⋅⋅⋅π interactions, are studied by computational methods. Stable complexes are formed with bromide, chloride, fluoride or hydroxide anions, which exhibit strong anion⋅⋅⋅π interactions in the gas phase. Following the sequence of the polarizing power of the anions, hydroxide and fluoride complexes are the most strongly interacting. The presence of a small number of water molecules strongly affects the anion⋅⋅⋅π interactions, especially for hydroxide and fluoride complexes, so the differences in interaction strength among the anions drop significantly. The calculations suggest that a small number of water molecules can be crucial to reducing dehydration cost and contributing to stabilizing interactions with the naphthalendiimide units.
The Effects of Biological Environments on the Electron‐Relay Functionality of Tryptophan Residues in Proteins
Authors: Chen Xiaohua , Dai Hongjing , Li Jilai , Huang Xuri , Wei Zidong
Published: December 2011

Clarifying the contribution of tryptophan (Trp) to electron‐transfer (ET) processes in different protein surroundings can help to understand the effective pathway of ET in proteins. Interactions between Trp residues and protein microsurroundings involve intermolecular H‐bonds, cation and π‐electron clouds of aromatic rings, the secondary structure and π orbital of aromatic rings, and so on. Detailed analyses reveal that the microsurroundings play an important role in modulating the electron‐relay function of Trp in proteins. Generally, microsurroundings with strong Lewis acidity inhibit electron hole transport through Trp residues. Systems with weak Lewis acidity finely tune the electron‐relay ability of Trp in proteins, while those with strong Lewis basicity strongly enhance the electron‐relay ability of Trp residues.
Xenopus staufen2 is required for anterior endodermal organ formation
Authors: Bilogan Cassandra K. , Horb Marko E.
Published: December 2011

Defining the regulatory molecular networks involved in patterning the developing anterior endoderm is essential to understand how the pancreas, liver, stomach, and duodenum are discretely specified from each other. In this study, we analyzed the expression and function of the double‐stranded RNA‐binding protein Staufen2 in Xenopus laevis endoderm. We found that staufen2 was broadly expressed within the developing endoderm beginning at gastrulation becoming localized to the anterior endoderm at later stages. Through morpholino‐mediated knockdown, we demonstrate that Staufen2 function is required for proper formation of the stomach, liver, and pancreas. We define that its function is required during gastrulation for proper patterning of the dorsal‐ventral axis and that it acts to regulate expression of BMP signaling components. genesis 50:251–259, 2012. © 2012 Wiley Periodicals, Inc.
Nematode‐induced interference with the anti‐Plasmodium CD8+ T‐cell response can be overcome by optimizing antigen administration
Authors: Kolbaum Julia , Tartz Susanne , Hartmann Wiebke , Helm Susanne , Nagel Andreas , Heussler Volker , Sebo Peter , Fleischer Bernhard , Jacobs Thomas , Breloer Minka
Published: December 2011

Malaria is still responsible for up to 1 million deaths per year worldwide, highlighting the need for protective malaria vaccines. Helminth infections that are prevalent in malaria endemic areas can modulate immune responses of the host. Here we show that Strongy‐Ioides ratti, a gut‐dwelling nematode that causes transient infections, did not change the efficacy of vaccination against Plasmodium berghei. An ongoing infection with Litomosoides sigmodontis, a tissue‐dwelling filaria that induces chronic infections in BALB/c mice, significantly interfered with vaccination efficacy. The induction of P. berghei circumspor‐ozoite protein (CSP)‐specific CD8+ T cells, achieved by a single immunization with a CSP fusion protein, was diminished in L. sigmodontis‐infected mice. This modulation was reflected by reduced frequencies of CSP‐specific CD8+ T cells, reduced CSP‐specific IFN‐y and TNF‐a production, reduced CSP‐specific cytotoxicity, and reduced protection against P. berghei challenge infection. Implementation of a more potent vaccine regime, by first priming with CSP‐expressing recombinant live Salmonella prior to CSP fusion protein immunization, restored induction of CSP‐specific CD8+ T cells and conferred almost sterile immunity to P. berghei challenge infection also in L. sigmodontis‐infected mice. In summary, we show that appropriate vaccination regimes can overcome helminth‐induced interference with vaccination efficacy.
Theoretical Investigations of Mechanisms of Thermal Cleavage of E=E Bonds in Heavy Butadiene Systems (E = C, Si, Ge, Sn, and Pb)
Authors: Sheu Jeng‐Horng , Su Ming‐Der
Published: December 2011

The potential energy surfaces for the intramolecular reactions of heavy 1,3‐butadiene have been explored using DFT. All the stationary points, which include the heavy 1,3‐butadienes (R2E=ER–ER=ER2, E = group 14 element), intramolecular fragments, transition states, and the products, were completely optimized at the B3LYP/LANL2DZ level of theory. Five 1,3‐butadiene species, which include carbon, silicon, germanium, tin, and lead, were chosen as model reactants. Our theoretical findings suggest the following: (1) both sterically bulky substituents attached to the heavy butadiene and the weakness of the E=E double bond lead to the easy cleavage of one E=E double bond in heavy 1,3‐butadiene and (2) for two intramolecular reactions (cycloaddition and 1,2‐migration) of the heavy 1,3‐butadienes with sterically overcrowded substituents, the lighter the E atoms involved in the 1,3‐butadiene molecule, the smaller the intramolecular barrier, the lower the reaction enthalpy, and the more facile its intramolecular reaction at room temperature. Furthermore, a configuration‐mixing model has been used to rationalize the computational results, and the results obtained allow a number of predictions to be made.
Extended finite element method for viscous flow inside complex three‐dimensional geometries with moving internal boundaries
Authors: Fard Arash Sarhangi , Hulsen Martien A. , Anderson Patrick D.
Published: December 2011

A three‐dimensional extended finite element method is presented to simulate Stokes flow in complex geometries with internal moving parts. Instead of re‐meshing the flow domain, the kinematics of the internal objects are imposed on the conservation equations using a constraint, implemented with a Lagrangian multiplier. To capture discontinuities of field variables, such as pressure and velocity, on the intersected elements, XFEM is used. To validate our method, it is first applied to a relatively simple problem, that is, the flow around a cylinder in a channel. The results are verified by comparing with a boundary‐fitted solution. After validation of the model and its implementation, the three‐dimensional flow in a twin‐screw extruder is simulated and the results are compared with experimental data from literature. XFEM shows very good accuracy for complex geometries with internal moving parts and narrow gap regions where the shear rate is orders of magnitude higher than in other regions. Copyright © 2011 John Wiley & Sons, Ltd.
A C-terminal tyrosine-based motif in the bile salt export pump directs clathrin-dependent endocytosis
Authors: Lam Ping , Xu Shuhua , Soroka Carol J. , Boyer James L.
Published: December 2011

The liver-specific bile salt export pump (BSEP) is crucial for bile acid–dependent bile flow at the apical membrane. BSEP, a member of the family of structurally related adenosine triphosphate (ATP)-binding cassette (ABC) proteins, is composed of 12 transmembrane segments (TMS) and two large cytoplasmic nucleotide-binding domains (NBDs). The regulation of trafficking of BSEP to and from the cell surface is not well understood, but is believed to play an important role in cholestatic liver diseases such as primary familial intrahepatic cholestasis type 2 (PFIC2). To address this issue, BSEP endocytosis was studied by immunofluorescence and a cell surface enzyme-linked immunosorbent assay (ELISA) endocytosis reporter system using a chimera of the interleukin-2 receptor α (previously referred to as Tac) and the C-terminal tail of BSEP (TacCterm). An autonomous endocytosis motif in the carboxyl cytoplasmic terminus of BSEP was identified. We define this endocytic motif by site-directed mutagenesis as a canonical tyrosine-based motif 1310YYKLV1314 (Yxxϕ). When expressed in HEK293T cells, TacCterm is constitutively internalized via a dynamin- and clathrin-dependent pathway. Mutation of the Y1310Y1311 amino acids in TacCterm and in full-length human BSEP blocks the internalization. Subsequent sequence analysis reveals this motif to be highly conserved between the closely related ABCB subfamily members that mediate ATP-dependent transport of broad substrate specificity.

Conclusion:

Our results indicate that constitutive internalization of BSEP is clathrin-mediated and dependent on the tyrosine-based endocytic motif at the C-terminal end of BSEP.
The effect of LED lighting on color discrimination and preference of elderly people
Authors: Cheng Wenting , Ju Jiaqi , Sun Yaojie , Lin Yandan
Published: December 2011

The purpose of this study is to find out the effects of light‐emitting diode (LED) lighting on elderly people's color discrimination and preference, to improve the lighting environment for elderly people. In this study, experiments were conducted under LED lighting with two different spectra (with color‐correlated temperature [CCT] of 2800K and 6000K), and three different illuminance levels (30lx; 100lx; 1000lx). Six elderly observers (aged 55–65 years) participated in the experiments and were exposed to each lighting condition to finish one trial of a color discrimination test (Farnsworth–Munsell 100‐Hue Test) and a 7‐scale, 6‐item preference evaluation test. We conclude that elderly people perform better in color discrimination with higher CCT of LED light sources, which compensate for their decreased lens transmission at short wavelength. Their performance also increases with higher illuminance (30lx‐1000lx) of LED lighting. Meanwhile, they prefer higher illuminance, which makes them find the lighting environment more comfortable, brighter, and better for reading; but for CCT, although they feel a higher CCT is better for reading, they still have different tastes regarding CCT of light sources. © 2011 Wiley Periodicals, Inc.
The influence of elderly vision degradation on subjective rating of floor slipperiness
Authors: Hsu Yao‐Wen
Published: December 2011

This study investigated the influence of elderly vision degradation on subjective rating of floor slipperiness and the correlation between the subjective ratings and objective measures. Slips and falls are common causes of injures and fatalities in the elderly population. Many slips and falls may be attributed to environmental risks and misjudgment of floor slipperiness by vision degradation. Environmental risks are generally caused by a slippery floor. The coefficient of friction (COF) is one of the most commonly used indices to assess floor slipperiness. The measurements conducted in this study acquired the COF on four floors under three surface conditions (dry, sand‐covered, and wet). The results showed that the dry condition has the highest COF and the wet condition has the lowest. Thirty elderly persons and thirty younger persons were recruited for vision screening. The vision degradation in elders was significant, with most elders having eye diseases. The subjective ratings of floor slipperiness were recorded for these subjects. Although both age groups had a similar rating trend with the COF measures, the correlation between rating and COF for younger persons was significantly stronger than that for elders. The results also showed that the smooth floor and the sand‐covered condition both cause lower correlation coefficients between rating and COF for elders. The results could be used to reduce slip and fall accidents by elderly persons. © 2011 Wiley Periodicals, Inc.
Effect of spatial resolution on regionalization of hydrological model parameters
Authors: Singh Shailesh Kumar , Bárdossy András , Götzinger J. , Sudheer K. P.
Published: December 2011

Lack of availability of historical data series is one of the major hindrances in hydrological modelling. Regionalization of hydrological model parameters is one of the solutions to obtain the parameters for ungauged basins. Recently, lots of methodologies have been developed. They can be categorized as model calibration then fitting regression between model parameters and catchments characteristics, using some kind of transfer function. The aim of this study was to compare different regionalization methods as well as to look how the spatial resolution affects regionalization. In this study, a modified Lipschitz and monotony condition was used for regionalization. To identify the effect of the model resolution, the parameters of a distributed and semi‐distributed version of the Hydrologiska Byråns Vattenbalansavdelning (HBV) model were regionalized. The study was conducted at the upper Neckar catchment of southwest Germany. It has been found that the combination of Lipschitz and monotony condition has performed reasonably. It has been seen that the distributed model structure has outperformed the semi‐distributed model structure. It shows under present data conditions that higher model resolution can describe processes of ungauged basins reasonably. Copyright © 2011 John Wiley & Sons, Ltd.
Comment on ‘García‐Santos G, Bruijnzeel LA. 2011. Rainfall, fog and throughfall dynamics in a subtropical ridge top cloud forest, National Park of Garajonay (La Gomera, Canary Islands, Spain). Hydrological Processes 25: 411–417’
Authors: Ritter Axel , Regalado Carlos M.
Published: December 2011

A previous study aiming to characterize the water dynamics of a cloud forest in the Garajonay National Park (La Gomera) from measurements taken in a plot located in the upper part of a selected watershed within the park is here commented. Reported magnitudes of hydrological variables and conclusions based on them are in disagreement with those of numerous studies carried out previously at the same site. Large data dispersion and inapplicability of some of the hypothesis assumed are shown to invalidate most of the results. Copyright © 2011 John Wiley & Sons, Ltd.
Keeping the spirit alive: using feminist methodology to address silencing
Authors: Shpungin Elaine , Allen Nicole , Loomis Colleen , DelloStritto Mary Ellen
Published: December 2011

This article describes a feminist intervention to raise awareness about, and problematize, the pervasive experience of silencing, as reported by women, people of color, students, people identifying as gay, lesbian, bisexual, transgender, and queer (GLBTQ), people with national origins outside of North America, and people with disabilities, within the Society for Community Research and Action (SCRA). A theater‐based intervention was designed and scripts were written from real‐life experiences that defined and described the problem of silencing as structural. We highlight three main points that emerged from intervention: (a) nontraditional approaches that step outside the cultural norms of a setting have great potential for raising awareness; (b) questions of power, privilege, and voice continue to be central considerations when using feminist‐based anti‐oppression methods; and (c) although acts of silencing can occur at the individual level, they thrive in an environment in which power, privilege, and historical inequities operate invisibly (without being named, acknowledged, or addressed). © 2011 Wiley Periodicals, Inc.
Embodying critical feminism in community psychology: unraveling the fabric of gender and class
Authors: Angelique Holly
Published: December 2011

In this article, I offer a critical feminist theoretical reflection on my lived experiences as a working‐class White woman as a challenge to some of the dominant narratives in academia. In particular, I describe my development of feminist and class‐consciousness as an “organic intellectual.” I discuss changes to my working‐class identity and the challenges of breaking through the glass‐class ceiling as an academician. I reveal how stigma management has irrevocably shaped my academic life and how my attempts at cultural suicide have overshadowed my professional and personal lives. I ask for a radical critique of higher education and argue for the importance of community psychology to infuse feminism and class consciousness into the field to address societal power asymmetries and to approach its value stance as a discipline. © 2011 Wiley Periodicals, Inc.
Where's the feminism in mothering?
Authors: D'Arcy Catherine , Turner Colleen , Crockett Belinda , Gridley Heather
Published: December 2011

This article is a reflective narrative bringing together personal, collective, and action learning reflections from three women: all mothers, feminists, and community psychology practitioners. Its focus on mothering highlights the interconnectedness and tensions across these roles, as well as the shared learnings arising from this collaboration. The article draws on our experiences in two participatory action research projects in different parts of Melbourne, Australia, to illustrate how our feminism informed approaches to improving mothers' and children's well‐being within a community environment. Learnings for practice include the importance of support and partnership with and empowerment of mothers in all their diversity, and of community change towards communal and child‐centered structures. The combined community psychology and feminist focus may assist those working with mothers in other communities. Sociocultural and political considerations include individualistic notions of motherhood, judgements about '”good” and “neglectful” mothers, and lack of priority for children's needs in community contexts. © 2011 Wiley Periodicals, Inc.
Feminist education and feminist community psychology: experiences from an Irish context
Authors: Moane Geraldine , Quilty Aideen
Published: December 2011

This article describes experiences in an Irish context of education programs delivered in 2 communities, 1 based on class (a working class urban community) and 1 based on sexual orientation (an urban lesbian, gay, bisexual, and transgender community). It aims to illustrate how feminist education can play an important role in feminist community psychology. Principles and practices of feminist education, or feminist pedagogy, have a great deal in common with feminist community psychology, but have been most often practiced in academic rather than in community settings. Feminist education in community settings provides a participatory and dialogical context in which knowledge can be cocreated from the bottom up. It allows for the exploration of diversity and the development of a political analysis that can further involvement in change at a number of different levels. Research on the feminist education programs described here indicates that participants were more likely to make changes in their lives, to obtain employment and/or further education, and to be more involved in community and other forms of action for change. © 2011 Wiley Periodicals, Inc.