bluuebunny/crossref_metadata_2025 huggingface dataset:
B1 mapping of liquid NMR transversal RF coils: Analysis of heterogeneity and nonlinearity
Authors: Nagashima Kaz
Published: February 2012

B1 fields generated by transversal RF coils in a high‐resolution NMR probe were studied using a nutation experiment combined with gradient echo 1D‐profiling. Signal amplitude, B1 strength, and relaxation time were mapped as a function of longitudinal axial position. Numerical Bloch simulations in a rotating frame could reproduce the overall features of the experimentally observed nutation profiles. The 3D rotating frame trajectories of magnetization during pulsing are presented in spherical coordinates. Nutating magnetization (i.e., sinusoidal oscillation) was detectable even outside the RF coil, although the signal amplitude was low and the spin relaxation during pulsing was fast. As the axial position got closer to the edges of the RF coil, low frequency components began overlapping on the nutating component. At the edge regions, the low frequency magnetizations dominated and the oscillating component almost disappeared, resulting in a cycloidal 3D trajectory of magnetization. Inside the RF coil, the low frequency component increased the frequency of oscillation as the axial position got closer to the center. Only a narrow central region of the RF coil gave a near linear response against pulse width, wherein the highest B1 field strength and very small relaxation were observed. A significant nonlinearity between pulse duration and flip angle was observed in the edge portion of the RF coil and at the outside. The heterogeneity and nonlinearity led to an inaccurate 90° pulse width when the pulse duration at null points (e.g., 180° or 360°) was simply divided by 2 or 4. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 41B: 1–12, 2012
Quadrature RF coil for in Vivo brain MRI of a macaque monkey in a stereotaxic head frame
Authors: Roopnariane Colin A. , Ryu Yeun‐chul , Tofighi Mohammad‐reza , Miller Patti A. , Oh Sukhoon , Wang Jianli , Park Bu SIK , Ansel Lukas , LIEU Christopher A. , Subramanian Thyagarajan , YANG Qing X. , Collins Christopher M.
Published: February 2012

We present a quadrature volume coil designed for brain imaging of a macaque monkey fixed in a sphinx position (facing down the bore) within a stereotactic frame at 3 T, where the position of the monkey and presence of the frame preclude use of existing coils. Requirements include the ability to position and remove the coil without disturbing the position of the monkey in the frame. A saddle coil and a solenoid were combined on a modified cylindrical former and connected in quadrature as to produce a homogeneous circularly polarized field throughout the brain. To allow the loops of the saddle coil to encompass the ear posts, partial disassembly and reassembly were facilitated by embedding pin and socket contacts into separate pieces of the former. Coil design included simulation of the electromagnetic fields for the coil containing a 3D model of a monkey's head. The resulting coil produced adequate homogeneity and signal‐to‐noise ratio throughout the brain. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 41B: 22–27, 2012
Improvement of vitamin D status resulted in amelioration of biomarkers of systemic inflammation in the subjects with type 2 diabetes
Authors: Shab‐Bidar Sakineh , Neyestani Tirang R. , Djazayery Abolghassem , Eshraghian Mohammad‐Reza , Houshiarrad Anahita , Kalayi Ali , Shariatzadeh Nastaran , Khalaji Niloufar , Gharavi A'azam
Published: February 2012

Background

Both vitamin D deficiency and inflammation have been linked to cardiovascular disease, the major cause of death in diabetes. In this study, the effects of daily intake of vitamin D‐fortified yoghourt drink (doogh) on systemic inflammatory biomarkers in subjects with type 2 diabetes (T2D) were investigated.

Subjects and methods

In this 12‐week randomized controlled trial, T2D subjects received either plain doogh (PD; containing 170 mg calcium and no detectable vitamin D/250 mL, n1 = 50) or vitamin D3‐fortified doogh (FD; containing 170 mg calcium and 500 IU/250 mL, n2 = 50) twice a day. Glycemic status, body fat mass and systemic inflammatory biomarkers including serum highly sensitive C‐reactive protein (hsCRP), serum amyloid A (SAA), interleukin(IL)‐2, IL‐6, IL‐10 and tumour necrosis factor (TNF)‐α were evaluated at the beginning and after the intervention. Data were expressed as either mean ± SD or median (interquartile range) whenever they had either normal or non‐normal distribution, respectively.

Results

In the patients receiving the vitamin D fortified drink, compared with those receiving the unfortified drink, a significant increase in serum 25(OH)D was accompanied by significant changes in TNF‐α (−57.9 (−264.6) versus +106.3 (683.2), p = 0.044), IL‐6 (−6.3 (−69.2), p = 0.002), hsCRP (−0.39 (−1.50) versus +0.8 (1.52), p < 0.001), SAA (−14.2 ± 44.5 versus +5.6 ± 37.5 mg/L, p = 0.022) and IL‐10 (+38.7 ± 157.0 versus −51.9 ± 165.2 ng/L, p = 0.013). The between‐group differences of hsCRP, SAA and IL‐6 changes remained significant even after controlling for changes quantitative insulin check index (p < 0.001, p < 0.001 and p = 0.009, respectively).

Conclusions

Improvement of vitamin D status of T2D subjects resulted in amelioration of the systemic inflammatory markers. This may have preventive implications against cardiovascular disease and other diabetic complications. Copyright © 2012 John Wiley & Sons, Ltd.
Hox transcription factors influence motoneuron identity through the integrated actions of both homeodomain and non‐homeodomain regions
Authors: Misra Mala , Sours Emily , Lance‐Jones Cynthia
Published: February 2012

Background: Hox transcription factors play a critical role in the specification of motoneuron subtypes within the spinal cord. Our previous work showed that two orthologous members of this family, Hoxd10 and Hoxd11, exert opposing effects on motoneuron development in the lumbosacral (LS) spinal cord of the embryonic chick: Hoxd10 promotes the development of lateral motoneuron subtypes that project to dorsal limb muscles, while Hoxd11 represses the development of lateral subtypes in favor of medial subtypes that innervate ventral limb muscles and axial muscles. The striking degree of homology between the DNA‐binding homeodomains of Hoxd10 and Hoxd11 suggested that non‐homeodomain regions mediate their divergent effects. In the present study, we investigate the relative contributions of homeodomain and non‐homeodomain regions of Hoxd10 and Hoxd11 to motoneuron specification. Results: Using in ovo electroporation to express chimeric and mutant constructs in LS motoneurons, we find that both the homeodomain and non‐homeodomain regions of Hoxd10 are necessary to specify lateral motoneurons. In contrast, non‐homeodomain regions of Hoxd11 are sufficient to repress lateral motoneuron fates in favor of medial fates. Conclusions: Together, our data demonstrate that even closely related Hox orthologues rely on distinct combinations of homeodomain‐dependent and ‐independent mechanisms to specify motoneuron identity. Developmental Dynamics 241:718–731, 2012. © 2012 Wiley Periodicals, Inc.
A method of finding business risk factors using the characteristics of probability distributions of effect ratios on qualitative and quantitative hybrid simulation
Authors: Samejima Masaki , Negoro Keisuke , Mitsukuni Koshichrio , Akiyoshi Masanori
Published: February 2012

We propose a method of finding business risk factors in a qualitative and quantitative hybrid time‐series simulation. The effect ratios of qualitative arcs in the hybrid simulation vary the output values of the simulation, so we define the effect ratios causing risks as business risk factors. Finding business risk factors in the entire ranges of effect ratios is time‐consuming. It is considered that the probability distributions of effect ratios at the present time step and those at the previous time step are similar, and thus that the probability distributions at the present time step can be estimated. Our method finds business risk factors effectively in only the estimated ranges. Experimental results show that the precision and recall rate are 86%, and that search time is decreased by at least 20%. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(3): 55–65, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10369
System for precise dissemination of frequency standard via optical fiber
Authors: Amemiya Masaki , Imae Michito , Fujii Yasuhisa , Suzuyama Tomonari , Naito Takashi , Urakawa Junji , Ebihara Kiyokazu , Terunuma Nobuhiro
Published: February 2012

A precise frequency dissemination system using optical fiber is studied. The purpose of the system is to transmit a frequency standard with little deterioration to many distant users. It is composed of a phase compensation transmitter, bidirectional optical amplifiers, optical amplified distributor, and receiver. The goal of the system is to achieve stable transmission of hydrogen maser‐class signals. For short‐term stability, the required optical received power to realize an Allan deviation of 1 × 10–13 (average time of 1 s) is shown. For long‐term stability, a new compensation method using a third wavelength transmission is effective to suppress phase fluctuation induced by temperature changes in the fiber. Experimental results show a stability of 8 × 10–17 at 105 s in a fiber link of 160 km in all with one bidirectional amplifier. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(3): 45–54, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10372
Benzyl Ether‐Substituted Phosphido–Borane Complexes of the Alkali Metals
Authors: Izod Keith , Watson James M. , Clegg William , Harrington Ross W.
Published: February 2012

Reduction of {(Me3Si)2CH}PCl(C6H4‐2‐CH2OMe) withLiAlH4, followed by reaction with BH3·SMe2, gives the phosphane–borane {(Me3Si)2CH}PH(BH3)(C6H4‐2‐CH2OMe) (2) in good yield. Compound 2 undergoes rapid deprotonation on treatment with nBuLi, PhCH2Na or PhCH2K to give the corresponding alkali metal phosphido–borane complexes [[{(Me3Si)2CH}P(BH3)(C6H4‐2‐CH2OMe)]ML]2 [ML = Li(THF) (3), Na(tmeda) (4), K(pmdeta) (5)] after crystallization in the presence of the respective co‐ligand L. The exact binding mode of the phosphido–borane ligand depends on the nature of the metal center in each case. However, all three alkali metal complexes crystallize as discrete dimers exhibiting M–P, M–O and M···BH3 contacts.
Discovery of Dipeptide‐Derived Catalysts for the Enantioselective Addition of Dimethylzinc to Aldehydes
Authors: Kang Seock Yong , Park Yong Sun
Published: February 2012

A new class of modular chiral catalysts derived from various amino acid‐L‐Pro dipeptides was prepared, and the catalysts were tested for their ability to catalyze the enantioselective addition of dimethylzinc to aromatic aldehydes. Dipeptides derived from L‐Asp‐L‐Pro were identified as effective catalysts for the addition at room temperature with up to 97:3 er and 95 % yield.
High resolution sensors in space and time for determination saltation and creep intensity
Authors: Schönfeldt Hans‐Jürgen
Published: February 2012

The measurement of aeolian sand transport rates at high temporal and spatial resolution is crucial for further progress in testing and developing numerical models of sand movement by wind and in the modelling of sand dunes, ripples and so on. This paper reports the development and field testing of two sand transport sensors. The first one, a webcam commonly used with personal computers, is a new device in aeolian research. The webcam frame transfer is triggered by a sonic anemometer every 0·1 second. Consecutive frames are compared and analysed in real‐time by a computer program. Changes in pixel light intensity exceeding a threshold level are recorded and interpreted as grain movements. The second sensor is a small‐sized ‘Saltiphone’‐type device made of simple loudspeakers with a diameter of 15 mm as used in MP3 players. It can be deployed as a 2 × 3 array of six such devices distributed to enable horizontal and vertical spatial sampling of the sand flux.

The devices are tested under field conditions. Both signals and the sum of microphone impacts over 15 minutes are compared to data gathered using a Guelph sand trap, and very good agreement is found. Measurements in a wind tunnel using sieved natural sand indicate that the webcam can be used to infer additional information about the grain size. As an application, the fluid and impact thresholds for aeolian sand transport are investigated in field measurements by analysing the onset and breakdown of saltation in gust and lull intervals of rising and falling wind speeds, respectively. In this way, constitutive equations for sand transport in terms of the wind speed can be tested. If viable, they can be employed to infer estimates for the thresholds by minimizing the root‐mean‐square error between measured and calculated transport data. Copyright © 2012 John Wiley & Sons, Ltd.
Photoacoustic imaging using an adaptive interferometer with a photorefractive crystal
Authors: Hochreiner Armin , Berer Thomas , Grün Hubert , Leitner Michael , Burgholzer Peter
Published: February 2012

In this paper we report on remote three‐dimensional photoacoustic imaging without the need for a coupling agent or other aids (e.g. detector foils) by utilizing a two‐wave mixing interferometer (TWMI). In this technique the beams coming from sample and reference are brought to interfere in a Bi12SiO20 photorefractive crystal (PRC). Such a setup allows the measurement of ultrasonic displacements on rough sample surfaces. After data acquisition the initial pressure distribution is reconstructed by a Fourier domain synthetic aperture focusing technique (FSAFT). We present three‐dimensional imaging of a hair ribbon phantom, on biological samples with embedded artificial blood vessels or pig bristles, and measurements on a human forearm in‐vivo. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chitosan/collagen scaffold containing bone morphogenetic protein‐7 DNA supports dental pulp stem cell differentiation in vitro and in vivo
Authors: Yang Xuechao , Han Guangli , Pang Xin , Fan Mingwen
Published: February 2012

In this study, porous chitosan/collagen scaffolds were prepared through a freeze‐drying process, and loaded with the plasmid vector encoding human bone morphogenetic protein‐7 (BMP‐7) gene. To investigate the feasibility and efficacy of this gene‐activated scaffold on dental tissue engineering, human dental pulp stem cells (DPSCs) were seeded in this scaffold for in vitro and in vivo study. In vitro results indicated that cells can be transfected successfully by loaded plasmid and secrete BMP‐7 until day 24. Evaluation of DNA content, ALP activity, calcium content, SEM, and real‐time PCR revealed that cells on gene‐activated scaffold showed better proliferation properties and odontoblastic differentiation behaviors than cells on pure scaffolds. Then, these cell–scaffold complexes were implanted subcutaneously and retrieved after 4 weeks for histology evaluation. In vivo results that gene‐activated scaffold group could still trace the existence of tranfected cells at week 4 and showed the upregulated expression of DSPP compared to pure scaffold groups. On the basis of our results, chitosan/collagen‐loaded BMP‐7 DNA appears to be an effective substrate candidate for gene delivery and indeed enhanced DPSCs differentiation toward an odontoblast‐like phenotype in vitro and in vivo. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
In vitro and in vivo characteristics of gentamicin‐supplemented polyvinylidenfluoride mesh materials
Authors: Klink C. D. , Binnebösel M. , Lambertz A. , Alizai H. P. , Roeth A. , Otto J. , Klinge U. , Neumann U. P. , Junge K.
Published: February 2012

To reduce infection rates after mesh implantation antibiotic‐coated meshes were designed. The aim of the study was to analyze biocompatibility and in vitro efficiency of a modified gentamicin‐supplemented polyvinylidenfluoride mesh. Twenty rats were randomized to two groups (PVDF group and Genta group). Mesh material was implanted subcutaneously. Blood samples were taken to determine the gentamicin serum concentration. Seven and 90 days after mesh implantation, animals were euthanized. The inflammatory tissue response was characterized by analyzing the foreign body granuloma. Cellular immune response was analyzed by immunohistochemical investigations. The collagen type I/III ratio was estimated by crosspolarization microscopy. In vitro agar diffusion test, suspension test, and gentamicin release were characterized. Agar diffusion and suspension test showed efficient antibiotic effects of the mesh in vitro. Serum concentrations of gentamicin showed a peak value 1 h postoperatively with a decline within the next day. The total size of the granuloma was significantly smaller in the Genta group compared to the PVDF group at both points of time. Except of a short period of increased expression of CD68 in the Genta group after 7 days, no further difference was found analyzing cellular immune response. The collagen type I/III ratio was widely constant analyzing the two mesh types without significant differences comparing both mesh materials. A significantly decreased foreign body granuloma formation compared to the pure PVDF mesh group was found. In vitro analysis showed efficient antibiotic effects of the Gentamicin supplementation compared to the pure PVDF mesh. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Histomorphological researches on large porous hydroxyapatite cylinder tubes with polylactic acid surface coating in different nonskeletal sites in vivo
Authors: Zhang Cong , Huang Peng , Weng Jie , Zhi Wei , Hu Yonghe , Feng Huaizhi , Yao Yimin , Li Shuo , Xia Tian
Published: February 2012

Porous hydroxyapatite (HA) ceramic cylinder tubes coated with polylactic acid on the exposed surfaces were implanted in four nonskeletal sites (omentum, peritoneum, vastus lateralis, and side of femur). Six months postoperatively, proper amount of Chinese ink was injected to dye the implanting areas. Decalcified and nondecalcified sections were observed under inverted microscope. The results showed that the soft tissues around the HA cylinder tubes in peritoneum, vastus lateralis, and side of femur groups appeared visible black. Some small blacked vascular architectures were also discernible. However in omentum group, only small number of blacked vessels existed. Histological observations indicated that vascularization and ossification occurred in peritoneum, vastus lateralis, and side of femur groups. In omentum group, there was no any sign of vascularization and ossification. A conclusion could be made in this study that excepting bones and muscles, parietal peritoneum could serve as a potential spot for culturing histoengineering hydroxyapatite (HA)‐polylactic acid (PLA) ceramic bone substitutes. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
Innovative corporate performance management: Delta dental case
Authors: Paladino Bob , Paladino Natalie N.
Published: February 2012

How do some of the most successful companies around organize and innovate to achieve results? In particular, how do they manage to innovate and change in a challenging market? This article provides answers through its presentation of a detailed case study. © 2011 Wiley Periodicals, Inc. Reprinted with permission of John Wiley & Sons.
Use lean accounting to add value to the organization
Authors: DeBusk Gerald K.
Published: February 2012

Companies pursuing Lean or Lean Six Sigma need changes in management, from their organizational structures to performance measurement. Management accountants must also change their accounting systems to support the new approaches to decision making and performance measurement; they can then use Lean Accounting to add value to their organizations. © 2012 Wiley Periodicals, Inc.
Dealing with man‐made trauma: The relationship between coping style, posttraumatic stress, and quality of life in resettled, traumatized refugees in the Netherlands
Authors: Huijts Irene , Kleijn Wim Chr. , van Emmerik Arnold A. P. , Noordhof Arjen , Smith Annemarie J. M.
Published: February 2012

This study investigated the relationship between coping style, posttraumatic stress disorder (PTSD) symptoms, and quality of life in traumatized refugees (N = 335). Participants had resettled in the Netherlands on average 13 years prior and were referred to a Dutch clinic for the treatment of posttraumatic psychopathology resulting from persecution, war, and violence. The majority (85%) of the research sample met diagnostic criteria for PTSD. Path analysis suggested a model in which PTSD symptoms (β = −.61, p < .001), social support seeking (β = .12, p < .05), and emotion‐focused coping (β = .13, p < .01) have a direct effect on quality of life. The role of avoidant and problem‐focused coping could be interpreted in 2 ways. Either these coping styles are influenced by PTSD severity and have no effect on quality of life, or these coping styles influence PTSD severity and therefore have an indirect effect on quality of life. Intervention strategies aimed at modifying coping strategies and decreasing PTSD symptoms could be important in improving the quality of life of traumatized refugees.
Exposure to interpersonal violence and risk for PTSD, depression, delinquency, and binge drinking among adolescents: Data from the NSA‐R
Authors: Cisler Josh M. , Begle Angela M. , Amstadter Ananda B. , Resnick Heidi S. , Danielson Carla Kmett , Saunders Benjamin E. , Kilpatrick Dean G.
Published: February 2012

Interpersonal violence (IPV) is associated with a range of subsequent negative outcomes; however, research has yet to test whether IPV operates as a specific risk factor for separate psychopathology outcomes, such as posttraumatic stress disorder (PTSD) symptoms, depressive symptoms, delinquent acts, or binge drinking. To address this, cumulative exposure to IPV and non‐IPV‐related traumatic events, PTSD symptoms, depressive symptoms, delinquent acts, and binge drinking were measured 3 times over approximately 3 years among a nationally representative sample of adolescents aged 12–17 (N = 3,614 at Wave 1). Results demonstrated that cumulative IPV exposure predicted subsequent PTSD, depression, delinquency, and binge drinking (βs = .07, .12, .10, and .09, respectively; all ps < .01) when all cross‐relationships (e.g., the effect of delinquency on future binge drinking) were in the model. Exposure to non‐IPV traumatic events generally did not confer vulnerability to subsequent psychopathology outcomes. Overall, findings from this study advance the literature in this area by exploring consequences for adolescents following cumulative IPV exposure.
Synthesis of Functional Sugar‐Based Polyurethanes
Authors: Ferris Cristina , de Paz M. Violante , Galbis Juan A.
Published: February 2012

Three new polyurethanes (PUs) with multiple pendant allyl groups were synthesized from L‐arabinitol as versatile materials for the preparation of tailor‐made PUs with varying degrees of functionalization. Their allyl functional groups can take part in thiol‐ene reactions to obtain greatly diverse materials. Thus, six new highly functional PUs were prepared by click chemistry to give polymers with NHBoc [NH‐CO‐OC(CH3)3], amino, carboxylic, and 1,2‐dihydroxyethyl side groups. The thermal stability of the novel PUs was investigated by thermogravimetric analysis and differential scanning calorimetry. This strategy provides a simple and versatile platform for the design of new materials whose functionality can be easily modified to anchor diverse biologically active molecules.
Design of Well‐Defined Monofunctionalized Poly(3‐hexylthiophene)s: Toward the Synthesis of Semiconducting Graft Copolymers
Authors: Mougnier Sébastien‐Jun , Brochon Cyril , Cloutet Eric , Fleury Guillaume , Cramail Henri , Hadziioannou Georges
Published: February 2012

The post‐functionalization of poly(3‐hexylthiophene) (P3HT) via various synthetic routes is reported. Well‐defined and monofunctionalized ω‐thiol‐terminated P3HT, ω‐carboxylic acid‐terminated P3HT, ω‐acrylate‐terminated P3HT, and ω‐methacrylate‐terminated P3HT are obtained in high yields through a straightforward procedure. From those, different novel P3HT‐based graft copolymers are synthesized following two routes: “grafting onto” and “grafting through” (macromonomer polymerization) methods. The synthesis of three types of graft copolymers is described. Each one has “rod” P3HT‐grafted side chains on a “coil” main chain, which can be polyisoprene, poly(vinyl alcohol), or poly(butyl acrylate). Each copolymer is characterized by size‐exclusion chromatography and NMR.
On the effects of deformation induced anisotropy in isotropic materials
Authors: Fuller T. , Brannon R. M.
Published: February 2012

Effects of recoverable deformation induced anisotropy in the elastic stiffness of isotropic materials are described. In isotropic materials, thermodynamics predicts coupling of hydrostatic and deviatoric responses. It is shown that the coupling of the two responses is more significant than previously recognized in the literature. Properly accounting for the coupling of hydrostatic and deviatoric responses requires re‐evaluating elastic materials characterization data, allowing for the coupled response. The result is an apparent decrease in the pressure sensitivity of the elastic shear modulus. The decrease in the pressure sensitivity of the shear modulus leads to stress paths that are more tangential to the yield surface in stress space, resulting in an increase in predicted elastic strain at each step of an elastic–plastic stress update. Consequently, predicted plastic strains and, in particular, volumetric plastic strains, are smaller than if recoverable deformation induced anisotropy had been neglected. The result is an associated plasticity model, which appears to be non‐associated. Copyright © 2012 John Wiley & Sons, Ltd.
CdS/Cu(In,Ga)S2 based solar cells with efficiencies reaching 12.9% prepared by a rapid thermal process
Authors: Merdes S. , Abou‐Ras D. , Mainz R. , Klenk R. , Lux‐Steiner M. Ch. , Meeder A. , Schock H. W. , Klaer J.
Published: February 2012

In this letter, we report externally confirmed total area efficiencies reaching up to 12.9% for CdS/Cu(In,Ga)S2 based solar cells. These are the highest externally confirmed efficiencies for such cells. The absorbers were prepared from sputtered metals subsequently sulfurized using rapid thermal processing in sulfur vapor. Structural, compositional, and electrical properties of one of these champion cells are presented. The correlation between the Ga distribution profile and solar cell properties is discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Photovoltaic application of O‐doped Wittichenite‐Cu 3 BiS 3: from microscopic properties to maximum efficiencies
Authors: Tablero C.
Published: February 2012

The electronic properties and the low environmental impact of Cu 3 BiS 3 make this compound a promising material for low‐cost thin film solar cell technology. From the first principles, the electronic properties of the isoelectronic substitution of S by O in Cu 3 BiS 3 have been obtained using two different exchange–correlation potentials. This compound has an acceptor level below the conduction band, which modifies the opto‐electronic properties with respect to the host semiconductor. In order to analyze a possible efficiency increment with respect to the host semiconductor, we have calculated the maximum efficiency of this photovoltaic absorber material. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of end‐functionalized polyethers by phosphazene base‐catalyzed ring‐opening polymerization of 1,2‐butylene oxide and glycidyl ether
Authors: Misaka Hideki , Tamura Eisuke , Makiguchi Kosuke , Kamoshida Kensuke , Sakai Ryosuke , Satoh Toshifumi , Kakuchi Toyoji
Published: February 2012

For the living ring‐opening polymerization (ROP) of epoxy monomers, the catalytic activity of organic superbases, tert‐butylimino‐tris(dimethylamino)phosphorane, 1‐tert‐butyl‐2,2,4,4,4‐pentakis(dimethylamino)‐2Λ5,4Λ5‐catenadi(phosphazene), 2,8,9‐triisobutyl‐2,5,8,9‐tetraaza‐1‐phosphabicyclo[3.3.3]undecane, and 1‐tert‐butyl‐4,4,4‐tris(dimethylamino)‐2,2‐bis[tris(dimethylamino)phosphoranylidenamino]‐2Λ5,4Λ5‐catenadi(phosphazene) (t‐Bu‐P4), was confirmed. Among these superbases, only t‐Bu‐P4 showed catalytic activity for the ROP of 1,2‐butylene oxide (BO) to afford poly(1,2‐butylene oxide) (PBO) with predicted molecular weight and narrow molecular weight distribution. The results of the kinetic, post‐polymerization experiments, and MALDI‐TOF MS measurement revealed that the t‐Bu‐P4‐catalyzed ROP of BO proceeded in a living manner in which the alcohol acted as the initiator. This alcohol/t‐Bu‐P4 system was applicable to the glycidol derivatives, such as benzyl glycidyl ether (BnGE) and t‐butyl glycidyl ether, to afford well‐defined protected polyglycidols. The α‐functionalized polyethers could be obtained using different functionalized initiators, such as 4‐vinylbenzyl alcohol, 5‐hexen‐1‐ol, and 6‐azide‐1‐hexanol. In addition, the well‐defined cyclic‐PBO and PBnGE were successfully synthesized using the combination of t‐Bu‐P4‐catalyzed ROP and click cyclization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Protective Effects of Pine Bark Extract on Hexavalent Chromium‐Induced Dermatotoxicity in Rats
Authors: Lee In‐Chul , Kim Sung‐Hwan , Shin In‐Sik , Moon Changjong , Park Soo‐Hyun , Kim Sung‐Ho , Park Seung‐Chun , Kim Hyoung‐Chin , Kim Jong‐Choon
Published: February 2012

The present study investigated the protective effects of pine bark extract (PBE) against hexavalent chromium [Cr(VI)]‐induced dermatotoxicity in rats. Skin reactions were evaluated by visual inspection, histopathological changes and oxidative stress parameters. Topical application of Cr(VI) produced a significant increase in the incidence and severity of erythema and edema upon visual inspection. Histopathological examination showed moderate to severe necrosis and desquamation in the epidermis and inflammation and hemorrhage in the dermis. In addition, an increased malondialdehyde (MDA) concentration, and decreased glutathione (GSH), catalase, superoxide dismutase, glutathione‐S‐transferase (GST) and glutathione reductase of the skin were observed in the Cr(VI) group. On the contrary, concomitant administration with PBE significantly improved Cr(VI)‐induced dermatotoxicity, evidenced by a decrease in the incidence and severity of skin irritation and histopathological lesions in a dose‐dependent manner. Moreover, PBE treatment reduced MDA concentrations and increased catalase and GST activities in skin tissues, indicating that concomitant administration with PBE effectively prevents Cr(VI)‐induced oxidative damage in rats. The results indicate that PBE has a protective effect against Cr(VI)‐induced dermatotoxicity and is useful as a protective agent against various dermal lesions induced by oxidative stress. Copyright © 2012 John Wiley & Sons, Ltd.
Permeation Through Plastic Dangerous Goods Packaging During Transport in Freight Containers – Detection of Potentially Explosive Mixtures in Containers Under Normal Conditions of Carriage
Authors: Bethke John , Goedecke Thomas , Jahnke Wolfgang
Published: February 2012

The key point within the scope of this research project was to find out whether there was a risk of creating an explosive atmosphere by permeation of flammable liquid compounds during transport of dangerous goods in freight containers under normal conditions of carriage. Therefore, all aspects that had an influence on the formation of such an atmosphere had to be considered. The most important influencing factors were permeation, air change in the freight container and ambient temperature. The first step was to investigate the permeation with different packaging materials, charge and temperatures. Furthermore, the air change rates of different freight containers were measured. A few climate tests with containers on ships, e.g. to Singapore, were performed to assess normal conditions of carriage. Another important point was measuring the solvent (toluene) concentration in the gas phase in a freight container loaded with plastic intermediate bulk containers (IBCs) filled with toluene. To confirm that the measured values were in the right range, the toluene concentration in the gas phase in a container was calculated with different packaging materials, air change rates and temperatures.

The results of the measurements and calculations have shown that safety layers in the packaging wall, e.g. the copolymer of ethylene and vinyl alcohol (EVOH) and polyamide, can reduce the rate of permeation by more than a decimal power, but the lower explosive limit of toluene is easily reached within a few hours at 40°C charge temperature if there is no barrier. Copyright © 2012 John Wiley & Sons, Ltd.
Turánnical hypergraphs
Authors: Allen Peter , Böttcher Julia , Hladký Jan , Piguet Diana
Published: February 2012

This paper is motivated by the question of how global and dense restriction sets in results from extremal combinatorics can be replaced by less global and sparser ones. The result we consider here as an example is Turán's theorem, which deals with graphs G = ([n],E) such that no member of the restriction set
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\mathcal {R}\end{align*} \end{document}
=
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\left( {\begin{array}{*{20}c} {[n]} \\ r \\ \end{array} } \right)\end{align*} \end{document}
induces a copy of Kr.

Firstly, we examine what happens when this restriction set is replaced by
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\mathcal {R}\end{align*} \end{document}
= {X∈
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\left( {\begin{array}{*{20}c} {[n]} \\ r \\ \end{array} } \right)\end{align*} \end{document}: X ∩ [m]≠∅︁}. That is, we determine the maximal number of edges in an n ‐vertex such that no Kr hits a given vertex set.

Secondly, we consider sparse random restriction sets. An r ‐uniform hypergraph
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\mathcal R\end{align*} \end{document}
on vertex set [n] is called Turánnical (respectively ε ‐Turánnical), if for any graph G on [n] with more edges than the Turán number tr(n) (respectively (1 + ε)tr(n) ), no hyperedge of
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}\mathcal {R}\end{align*} \end{document}
induces a copy of Kr in G. We determine the thresholds for random r ‐uniform hypergraphs to be Turánnical and to be ε ‐Turánnical.

Thirdly, we transfer this result to sparse random graphs, using techniques recently developed by Schacht [Extremal results for random discrete structures] to prove the Kohayakawa‐Łuczak‐Rödl Conjecture on Turán's theorem in random graphs.© 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2012
Greek letters in random staircase tableaux
Authors: Dasse–Hartaut Sandrine , Hitczenko Paweł
Published: February 2012

In this paper we study a relatively new combinatorial object called staircase tableaux. Staircase tableaux were introduced by Corteel and Williams in the connection with Asymmetric Exclusion Process and has since found interesting connections with Askey–Wilson polynomials. We develop a probabilistic approach that allows us to analyze several parameters of a randomly chosen staircase tableau of a given size. In particular, we obtain limiting distributions for statistics associated with appearances of Greek letters in staircase tableaux. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2012
The Discursive Positioning of Teachers: Native‐Speaking English Teachers and Educational Discourse in Hong Kong
Authors: Trent John
Published: February 2012

This article reports on a qualitative study that explored the discursive positioning of native‐speaking English teachers (NETs) in schools in Hong Kong. It draws on insights from discourse theory to examineNETs’ self‐positioning, and their positioning by other stakeholders, as part of a dynamic process of identity formation. The participants were eight teachers who were employed in primary and secondary schools under the Hong Kong Government's Native English Teacher scheme. The author conducted in‐depth interviews with each participant to gain an understanding of how the teachers discursively positioned themselves, and how they believed they were positioned by others, within their schools. The findings suggest thatNETs perceive challenges to their self‐positioning as professional language teachers from some local English teachers and school managers who seem to question the value of their teaching experiences and practices in the context of English language classrooms in Hong Kong. The article exploresNETs’ responses to the antagonism between the different subject positions that they consider are available to them in Hong Kong schools and discusses implications for changes to existing systems and culture within schools as well as for future research.
Effects of Instruction on Adolescent Beginners’ Acquisition of Request Modification
Authors: Li Qingping
Published: February 2012

This quasiexperimental study examined the effects of different focus‐on‐form techniques, and the durability of such effects, on adolescent beginners’ acquisition of request supportive moves. Three treatments were implemented: (1) the incidental group was exposed to input and involved in meaningful output activities; (2) the implicit group was aided by visual enhancement of the input; and (3) the explicit group was aided with metapragmatic information. Discourse completion test results show that, when learners are provided with pertinent input and chances for output, visual enhancement can boost their pragmatic development, while metapragmatic information might hinder such development. Only the input‐output activities (i.e., the incidental treatment) could produce durable effects in every aspect of the target features. The explicit treatment did produce durable effects in the acquisition of overall supportive moves. The effects of the visual enhancement were not durable. These results are discussed in terms of an interaction between the learner profile (young beginning learners), treatment characteristics, and the nature of target features.
Moduli stabilisation for chiral global models
Authors: Cicoli Michele , Mayrhofer Christoph , Valandro Roberto
Published: February 2012

Abstract

We combine moduli stabilisation and (chiral) model building in a fully con-sistent global set-up in Type IIB/F-theory. We consider compactifications on Calabi-Yau orientifolds which admit an explicit description in terms of toric geometry. We build globally consistent compactifications with tadpole and Freed-Witten anomaly cancellation by choosing appropriate brane set-ups and world-volume fluxes which also give rise to SU(5) or MSSM-like chiral models. We fix all the Kähler moduli within the Kähler cone and the regime of validity of the 4D effective field theory. This is achieved in a way compatible with the local presence of chirality. The hidden sector generating the non-perturbative effects is placed on a del Pezzo divisor that does not have any chiral intersection with any other brane. In general, the vanishing D-term condition implies the shrinking of the rigid divisor supporting the visible sector. However, we avoid this problem by generating r < n D-term conditions on a set of n intersecting divisors. The remaining (n − r) flat directions are fixed by perturbative corrections to the Kähler potential. We illustrate our general claims in an explicit example. We consider a K3-fibred Calabi-Yau with four Kähler moduli, that is a hypersurface in a toric ambient space and admits a ‘simple’ F-theory up-lift. We present explicit choices of brane set-ups and fluxes which lead to three different phenomenological scenarios: the first with GUT-scale strings and TeV-scale SUSY by fine-tuning the background fluxes; the second with an exponentially large value of the volume and TeV-scale SUSY without fine-tuning the background fluxes; and the third with a very anisotropic configuration that leads to TeV-scale strings and two micron-sized extra dimensions. The K3 fibration structure of the Calabi-Yau three-fold is also particularly suitable for cosmological purposes.
Quantification of metabolism in Saccharomyces cerevisiae under hyperosmotic conditions using elementary mode analysis
Authors: Parmar Jignesh H , Bhartiya Sharad , Venkatesh K V
Published: February 2012

Yeast metabolism under hyperosmotic stress conditions was quantified using elementary mode analysis to obtain insights into the metabolic status of the cell. The fluxes of elementary modes were determined as solutions to a linear program that used the stoichiometry of the elementary modes as constraints. The analysis demonstrated that distinctly different sets of elementary modes operate under normal and hyperosmotic conditions. During the adaptation phase, elementary modes that only produce glycerol are active, while elementary modes that yield biomass, ethanol, and glycerol become active after the adaptive phase. The flux distribution in the metabolic network, calculated using the fluxes in the elementary modes, was employed to obtain the flux ratio at key nodes. At the glucose 6-phosphate (G6P) node, 25% of the carbon influx was diverted towards the pentose phosphate pathway under normal growth conditions, while only 0.3% of the carbon flux was diverted towards the pentose phosphate pathway during growth at 1 M NaCl, indicating that cell growth is arrested under hyperosmotic conditions. Further, objective functions were used in the linear program to obtain optimal solution spaces corresponding to the different accumulation rates. The analysis demonstrated that while biomass formation was optimal under normal growth conditions, glycerol synthesis was closer to optimal during adaptation to osmotic shock.
Trophic structure of arthropods in Starling nests matter to blood parasites and thereby to nestling development
Authors: Wolfs Peter H. J. , Lesna Izabela K. , Sabelis Maurice W. , Komdeur Jan
Published: February 2012

Nestling development and long-term survival in many bird species depend on factors such as parental feeding, time of breeding and environmental conditions. However, little research has been carried out on the effect of ectoparasites on nestling development, and no research on the impact of the trophic structure of arthropods inhabiting the nest (combined effects of ectoparasitic mites and predatory mites feeding on ectoparasites). We assess nestling development of European Starlings (Sturnus vulgaris) in relation to the number of parasitic mites Dermanyssus gallinae (DG, a blood-sucking mite) and their predators, i.e. Androlaelaps casalis (AC), both dominant species of nidicolous arthropods in Starling nests. DG densities were not associated with nestling body mass or tarsus length during development (10 and 17 days of age), which contradicts our expectation that parasitic mites negatively influence growth. Furthermore, an increase in AC densities was associated with a significant decrease in body mass (not tarsus length) later during nestling development (at day 17—a proxy for nestling age—but not at day 10). The latter seems counterintuitive, but not when the inherent density-dependent delays in Lotka-Volterra predator–prey interactions are taken into account: a high density of predatory mites (AC) always arises after an increase of prey mites (DG). Thus, the high density of predatory mites indicates a preceding peak density of parasitic mites. Clearly, this explanation requires insight in the trophic structure of mites inhabiting Starling nests and bird nests in general. We conclude that multitrophic interactions (between predator, parasite and host) in nests should not be ignored when assessing nestling development.
Transcultural Diabetes Nutrition Therapy Algorithm: The Asian Indian Application
Authors: Joshi Shashank R. , Mohan V. , Joshi S. S. , Mechanick Jeffrey I. , Marchetti Albert
Published: February 2012

India and other countries in Asia are experiencing rapidly escalating epidemics of type 2 diabetes (T2D) and cardiovascular disease. The dramatic rise in the prevalence of these illnesses has been attributed to rapid changes in demographic, socioeconomic, and nutritional factors. The rapid transition in dietary patterns in India—coupled with a sedentary lifestyle and specific socioeconomic pressures—has led to an increase in obesity and other diet-related noncommunicable diseases. Studies have shown that nutritional interventions significantly enhance metabolic control and weight loss. Current clinical practice guidelines (CPGs) are not portable to diverse cultures, constraining the applicability of this type of practical educational instrument. Therefore, a transcultural Diabetes Nutrition Algorithm (tDNA) was developed and then customized per regional variations in India. The resultant India-specific tDNA reflects differences in epidemiologic, physiologic, and nutritional aspects of disease, anthropometric cutoff points, and lifestyle interventions unique to this region of the world. Specific features of this transculturalization process for India include characteristics of a transitional economy with a persistently high poverty rate in a majority of people; higher percentage of body fat and lower muscle mass for a given body mass index; higher rate of sedentary lifestyle; elements of the thrifty phenotype; impact of festivals and holidays on adherence with clinic appointments; and the role of a systems or holistic approach to the problem that must involve politics, policy, and government. This Asian Indian tDNA promises to help guide physicians in the management of prediabetes and T2D in India in a more structured, systematic, and effective way compared with previous methods and currently available CPGs.
Family planning in Nigeria and prospects for the future
Authors: Mandara Mairo
Published: February 2012

Nigeria, with its current demographics and without intervention, is set to double its population of 150 million people in 22 years. The government's population and health policies recognize family planning as a key intervention. However, unacceptably high unmet need for contraception exists in the country, which may indicate a lack of commitment for family planning. The 2008 Nigeria Demographic and Health Survey report shows that knowledge of any contraceptive method is widespread in Nigeria. Despite this knowledge, contraceptive prevalence is 15%. Knowledge of and actual use of contraceptives vary between states in the country and are influenced by sociodemographic factors. For family planning to move forward in Nigeria a joint effort is needed, with the government taking a leadership role in promoting the use of family planning and ensuring that stakeholders take individual responsibilities seriously.