bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased trabecular bone formation in mice lacking the growth factor midkine
Authors: Neunaber Claudia , Catala-Lehnen Philip , Beil F Timo , Marshall Robert P , Kanbach Vincent , Baranowsky Anke , Lehmann Wolfgang , Streichert Thomas , Ignatius Anita , Muramatsu Takashi , Schinke Thorsten , Amling Michael
Published: February 2010

Midkine (Mdk) and pleiotrophin (Ptn) comprise a family of heparin-binding growth factors known primarily for their effects on neuronal cells. Since transgenic mice overexpressing Ptn have been reported to display increased bone density, we have previously analyzed Ptn-deficient mice but failed to detect any abnormality of skeletal development and remodeling. Together with the finding that Mdk expression increases in the course of primary osteoblast differentiation, we reasoned that Mdk, rather than Ptn, could play a physiologic role in bone formation. Here, we show that Mdk-deficient mice display an increased trabecular bone volume at 12 and 18 months of age, accompanied by cortical porosity. Histomorphometric quantification demonstrated an increased bone-formation rate compared with wild-type littermates, whereas bone resorption was differentially affected in trabecular and cortical bone of Mdk-deficient mice. To understand the effect of Mdk on bone formation at the molecular level, we performed a genome-wide expression analysis of primary osteoblasts and identified Ank and Enpp1 as Mdk-induced genes whose decreased expression in Mdk-deficient osteoblasts may explain, at least in part, the observed skeletal phenotype. Finally, we performed ovariectomy and observed bone loss only in wild-type but not in Mdk-deficient animals. Taken together, our data demonstrate that Mdk deficiency, at least in mice, results in an increased trabecular bone formation, thereby raising the possibility that Mdk-specific antagonists might prove beneficial in osteoporosis therapy. © 2010 American Society for Bone and Mineral Research
A gradient‐directed Monte Carlo approach for protein design
Authors: Hu Xiangqian , Hu Hao , Beratan David N. , Yang Weitao
Published: February 2010

We develop a new global optimization strategy, gradient‐directed Monte Carlo (GDMC) sampling, to optimize protein sequence for a target structure using RosettaDesign. GDMC significantly improves the sampling of sequence space, compared to the classical Monte Carlo search protocol, for a fixed backbone conformation as well as for the simultaneous optimization of sequence and structure. As such, GDMC sampling enhances the efficiency of protein design. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Rethinking climate refugees and climate conflict: Rhetoric, reality and the politics of policy discourse
Authors: Hartmann Betsy
Published: February 2010

This paper critically examines the perceived threat of ‘climate refugees’ and ‘climate conflict’. It locates the ideological roots of these concepts in development theories and policy narratives about demographically induced migration, environmental refugees and environmental security. While alarmist rhetoric around climate refugees and conflict has been deployed by a variety of actors, including U.N. agencies, development NGOs, national governments, security pundits and popular media, the paper concentrates on its strategic use by U.S. defence interests. It raises the question of how the portrayal of climate change as a security threat could further militarise the provision of development assistance and distort climate policy. Copyright © 2010 John Wiley & Sons, Ltd.
Upscaling spatio‐temporal patterns of cation fluxes in acid forest soils
Authors: Zirlewagen Dietmar , von Wilpert Klaus
Published: February 2010

One main problem with current research on spatio‐temporal modeling of ion fluxes in forest soils is the separation of space and time effects in the soil‐monitoring concept. This article describes an approach to overcome this weakness. Time trends of point information on soil‐solution data (base‐cation concentrations and fluxes) are scaled by linking them to soil‐chemical data which is available in higher spatial resolution and can be upscaled to an area base. This approach is based on a combined evaluation of bulk soil and soil‐solution data using both statistical and process‐oriented methods. Multiple‐linear‐regression analyses coupled with geostatistics were developed to predict spatial patterns of exchangeable cation percentages. In a second step, empirical ion‐distribution coefficients were adapted according to Gapon using data of suction‐cup plots and bulk‐soil samples. Seasonally adjusted time‐series data of soil‐solution chemistry were then connected with the maps of the predicted exchangeable‐cation percentages by means of the Gapon equations. This evaluation step provided both time‐ and space‐dependent maps of cation concentrations in the soil solution. Finally, using the results of a water‐budget model it was possible to derive spatio‐temporal patterns of soil cation fluxes. Methodological limitations and the results of verification processes are discussed. The methods described can only be used in acidic soils and should not be used in soil layers rich in humus, since adsorption to C compounds differs from adsorption to clay minerals. The time increments of the models should be not shorter than yearly in order to suppress annual periodicity. Although the Gapon equations were not based on laboratory‐determined exchange solutions at quasi‐equilibrium, but rather on field data from the suction‐cup technique, the exchangeable‐cation percentages showed steady functions of selectivity coefficients. The methods tested at a watershed scale may be flexible enough to be applied at other scales as well.
Nitrogen mineralization from an organically managed soil and nitrogen accumulation in lettuce
Authors: Ribeiro Henrique M. , Fangueiro David , Alves Fátima , Ventura Rita , Coelho Dulce , Vasconcelos Ernesto , Cunha‐Queda Cristina , Coutinho João , Cabral Fernanda
Published: February 2010

The potential of an organically managed Cambic Arenosol to supply nitrogen (N) from either an applied commercial organic fertilizer (granulated hen manure), a compost produced on‐farm, or four different mixtures of both fertilizers was studied in a laboratory incubation and a pot experiment with lettuce. In the incubation experiment, a significant higher apparent N mineralization occurred after hen‐manure application (53.4% of the organic N applied) compared to compost (4.5%) or mixed‐fertilizer application (8.7% to 16.7%). The apparent N mineralization in a mixed treatment consisting of compost and half rate of hen manure (15.4% of the organic N applied) was significantly higher than that estimated based on the N mineralization for compost and hen‐manure treatments (7.6%), proving that a combined application of both fertilizers enhanced organic‐N mineralization when compared to separate fertilizer supply. In the pot experiment, a higher lettuce fresh‐matter yield was obtained with hen manure (1.9 kg m–2) than with compost (1.7 kg m–2) or unfertilized control treatment (1.3 kg m–2). Combined application of compost with only a half rate of hen manure led to yields (2.0 kg m–2) equal to those obtained with only hen manure. A good correlation was observed between the N‐mineralization incubation data and the N accumulated by lettuce plants in the pot experiment (r = 0.983). Hence, in the organic production of baby‐leaf lettuce, a mixture of compost and hen manure appears to be a good fertilization alternative, since it allows a reduction by half of the typical amount of commercial fertilizer usually applied (granulated hen manure), cutting fertilization costs, and providing an amount of available N that allows maintaining lettuce yields.
Fuzzy comprehensive evaluation for selecting mini watermelon cultivars
Authors: Hou Pei , Zhang Jing , Zhang Xian
Published: February 2010

BACKGROUND: The traditional method for selecting suitable mini watermelon cultivars has been shown to be flawed. The aim of the present study was to assess 11 mini watermelon cultivars using a new method, two‐level fuzzy comprehensive evaluation (FCE). Three different characteristics for selecting the best cultivars were chosen to establish the evaluation index system, namely commercial trait, early maturity and high yield quality. Fifteen specific factors were used to reflect these three characteristics.

RESULTS: According to the final results of FCE, Linglongwang was selected as the best of the 11 cultivars overall. Autocopulation F1 of Hai 024 × Hai 011 was ranked second overall, while Heimeiren × Yun 05‐2‐1‐1 was ranked lowest overall. Hai 051 × Hai 011 was the best cultivar in early maturity but worse in commercial trait and high yield quality than some other cultivars.

CONCLUSION: FCE can reflect the multiple characteristics of a cultivar objectively and precisely. This method has huge potential in selecting mini watermelon cultivars. Copyright © 2010 Society of Chemical Industry
Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture
Authors: Voogt Wim , Holwerda Harmen T , Khodabaks Rashied
Published: February 2010

BACKGROUND: Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture.

RESULTS: In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 µg iodine L−1, applied as iodate (IO3−) or iodide (I−), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I− than with IO3−. Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 µg iodine kg−1 total leaf fresh weight.

CONCLUSION: Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I− and IO3−. I− was more effective than IO3−. Fifty grams of iodine‐biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. Copyright © 2010 Society of Chemical Industry
Influence of Stabilizer Concentration on Transport Behavior and Thermopower of CNT‐Filled Latex‐Based Composites
Authors: Kim Yeon Seok , Kim Dasaroyong , Martin Kaylan J. , Yu Choongho , Grunlan Jaime C.
Published: February 2010

The influence of the stabilizer/SWNT ratio on the transport behavior of latex‐based polymer nanocomposites is examined in an effort to improve electrical conductivity while maintaining or improving the Seebeck coefficient (i.e., thermopower). Results show that phonon and electron transport are significantly affected by tube/tube junctions, and the carrier transport across the junctions can be manipulated by altering the stabilizer concentration. Electrical conductivity of composites containing 10 wt.‐% SWNT nearly doubles, becoming greater than 900 S · m−1, by changing the SWNT:GA ratio from 1:3 to 10:1, while thermal conductivity and Seebeck coefficient remain relatively constant (near 0.25 W · m‐K−1 and 40 µV · K−1, respectively).

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Change and Convergence of Polymer Distribution During Nonrandom Degradation
Authors: Tobita Hidetaka
Published: February 2010

The CLD development during nonrandom degradation is investigated, assuming the rate of bond scission depends on the chain length and the position of the bond within the chain. As the degradation proceeds, the polydispersity index $({\rm PDI} = \bar {P}_{\rm w} /\bar {P}_{\rm n} )$ usually approaches a fixed value pertinent to the degradation mechanism, independent of the initial distribution. The exact limiting values are presented for several cases. These values may be useful to estimate the degradation mechanisms. For example, if the limiting PDI is smaller than 2, the bonds in larger chains may be easier to break than shorter ones, and if it is smaller than 4/3, the size effect is not enough and the breakage may tend to occur in the middle of the chain.

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a‐SiC:H passivation for crystalline silicon solar cells
Authors: Ehling Christian , Werner Jürgen H. , Schubert Markus B.
Published: February 2010

This study aims at a better understanding of the electronic surface passivation of monocrystalline silicon wafers by thin amorphous silicon carbide (a‐SiC:H) layers. Annealing a‐SiC:H coated Si wafers in forming gas up to an annealing temperature Tan = 700 oC, reveals the correlation between the effective charge carrier lifetime τeff and structural features of the a‐SiC:H monitored by Fourier‐Transform Infra Red (FTIR) spectroscopy. Passivation layers with low carbon content yield effective lifetimes τeff > 1 ms for Tan = 600 °C. Increasing the C content lowers the thermal stability of the electronic passivation. Out of detailed FTIR measurements, the absorption strength ratio R permits statements of microvoids in the amorphous layers. Comparing R with the effective lifetimes enables a qualitative forecast concerning the temperature stability of a‐SiC:H passivation layers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between microstructure and residual stress of nanocrystalline silicon films
Authors: Chowdhury Amartya , Ray Swati
Published: February 2010

The nanocrystalline silicon films have been prepared using very high frequency PECVD technique. The deposition power density and hydrogen dilution of Silane were varied. The sizes of the grains varies from 6 nm to 32 nm for films deposited under different conditions. The stress of the nanocrystalline films have been estimated from (220) line. It is observed that compressive stress decreases and become tensile stress as Xc of the films increases with increase in power density. Whereas compressive stress increases as crystalline volume fraction increases with increase in hydrogen dilution. Maximum tensile stress and compressive stress obtained are 0.23 GPa and 5.1 GPa respectively. It is also observed that compressive stress in the film increases as grain size increases. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excimer laser wet oxidation of hydrogenated amorphous silicon
Authors: Persheyev Saydulla K. , Fan Yongchang , Reynolds Steve , Rose Mervyn J.
Published: February 2010

We present results of the excimer laser wet oxidisation of submicron thick hydrogenated amorphous silicon films (a‐Si:H) deposited on silicon wafer. The a‐Si:H film irradiation was carried out by multiple‐pulses, large‐spot, 20 ns KrF (248 nm) excimer laser and fluences of 140‐300 mJ/cm2, near to the silicon ablation threshold in an air atmosphere. The oxygen and hydrogen content and bonding in the thin films were analysed by Fourier Transform Infrared Spectroscopy (FTIR) techniques in the range 400‐4000 cm–1. We demonstrate that the presence of water molecules on the silicon surface will increase oxidation by 30‐40%. The bonded hydrogen content in the films after oxidation annealing is decreased from 12 down to around 1 atomic percent. Wet oxidised surfaces present highly hydrophobic properties which appears to be determined by the amorphous silicon structure transformation and silicon surface energy modification forming a silicon/oxide (nitride) interface. (© WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TiOxNy anti‐resonant layer ARROW waveguides
Authors: Carvalho Daniel O. , Albertin Katia F. , Alayo Marco I.
Published: February 2010

ARROW waveguides with sputtered‐TiOxNy anti‐resonant layers obtained with different nitrogen concentration in the gaseous mixture were fabricated and characterized. A study of the influence of this parameter on the losses of the waveguides is presented in this work. TiOxNy films have very high refractive indexes, which is a very important characteristic for the first ARROW layer, since this layer behaves like a Fabry‐Perot resonator in anti‐resonance. Optical and compositional properties of the TiOxNy films were also studied and the results are presented. These films were characterized by Rutherford Backscattering Spectroscopy (RBS), FTIRs, optical absorption and ellipsometry. The second anti‐resonant layer and the core of the waveguides were composed of thermally grown SiO2 and PECVD‐SiOxNy, respectively. Optical characterization results show propagation losses as low as 1.18 dB/cm for single‐mode waveguides fabricated with TiOxNy films obtained with 25% of nitrogen in the gaseous mixture. (© WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Half rotations leading to retention of stereochemistry in epoxide ring opening by selenocyanate ion: Insights from DFT modeling
Authors: Kalaiselvan Anbarasan , Muthukumar Kaliappan , Senthilnathan Dhurairajan , Maldivi Pascale , Venuvanalingam Ponnambalam
Published: February 2010

Stilbene oxide on reaction with selenocyanate ion in methanol (Culvenor et al., J Chem Soc 1949, 278) has been found to yield the corresponding stilbene with the deposition of metallic Se. For this reaction, a tentative mechanism involving “two half rotations” around the carbon–carbon bond based on the observed stereospecificity and formation of episelenide intermediate has been suggested. This reaction has been modeled at B3LYP/6‐31+G(d) level and the potential energy surface of the reaction has been explored. Computations suggest a backside attack of the selenocyanate ion to one of the epoxide carbon atoms to form a prereactive complex, two successive half‐rotations around the carbon–carbon bond in the opposite direction, the formation and decomposition of episelenide intermediate, and finally trans‐stilbene. Calculations besides agreeing excellently with experiment reveal many interesting mechanistic details that experimentalists could not unravel. Wiberg bond order analyses reveal the smooth progress in the bond changes during the course of the reaction. Solvent effect through PCM model calculations with methanol as solvent does not alter the gas phase results significantly. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
A UNIFIED APPROACH TO VARIOUS GENERALIZATIONS OF ARMENDARIZ RINGS
Authors: MARKS GREG , MAZUREK RYSZARD , ZIEMBOWSKI MICHAŁ
Published: February 2010

Let R be a ring, S a strictly ordered monoid, and ω:S→End(R) a monoid homomorphism. The skew generalized power series ring R[[S,ω]] is a common generalization of (skew) polynomial rings, (skew) power series rings, (skew) Laurent polynomial rings, (skew) group rings, and Mal’cev–Neumann Laurent series rings. We study the (S,ω)-Armendariz condition on R, a generalization of the standard Armendariz condition from polynomials to skew generalized power series. We resolve the structure of (S,ω)-Armendariz rings and obtain various necessary or sufficient conditions for a ring to be (S,ω)-Armendariz, unifying and generalizing a number of known Armendariz-like conditions in the aforementioned special cases. As particular cases of our general results we obtain several new theorems on the Armendariz condition; for example, left uniserial rings are Armendariz. We also characterize when a skew generalized power series ring is reduced or semicommutative, and we obtain partial characterizations for it to be reversible or 2-primal.
Mesoscopic and magnetic fabrics in arcuate igneous bodies: an example from the Mandi-Karsog pluton, Himachal Lesser Himalaya
Authors: JAYANGONDAPERUMAL R. , DUBEY A. K. , SEN K.
Published: February 2010

Field, microstructural and anisotropy of magnetic susceptibility (AMS) data from the Palaeozoic Mandi-Karsog pluton in the Lesser Himalayan region reveal a concordant relationship between fabric of the Proterozoic host rock and the granite. The pluton displays a prominent arcuate shape on the geological map. The margin-parallel mesoscopic and magnetic fabrics of the granite and warping of the host rock fabric around the pluton indicate that this regional curvature is either synchronous or pre-dates the emplacement of the granite body. Mesoscopic fabric, magnetic fabric and microstructures indicate that the northern part of the pluton preserves its pre-Himalayan magmatic fabric while the central and southern part shows tectonic fabric related to the Tertiary Himalayan orogeny. The presence of NW–SE-trending aplitic veins within the granite indicates a post-emplacement stretching in the NE–SW direction. Shear-sense indicators in the mylonites along the margin of the pluton suggest top-to-the-SW shearing related to the Himalayan orogeny. Based on these observations, it is envisaged that the extension that gave rise to this rift-related magmatism had a NE–SW trend, that is, normal to the trend of the aplite veins. Subsequently, during the Himalayan orogeny, compression occurred along this same NE–SW orientation. These findings imply that the regional curvature present in the Himachal Lesser Himalaya is in fact a pre-Himalayan feature and the pluton has formed by filling a major pre-Himalayan arcuate extension fracture.
Bring on the leprawns
Authors: Johannesson Nils-Lennart
Published: February 2010

Review of: Dimitra Fimi, Tolkien, Race and Cultural History: From Fairies to Hobbits. Palgrave Macmillan 2009. 252 pages. 9780230219519. Hardback £50.00

Nils-Lennart Johannesson, Stockholm University, Sweden
COMMODITIES, OWNERSHIP, AND THE EUSTACE DIAMONDS: THE VALUE OF FEMININITY
Authors: Sattaur Jen
Published: February 2010

In an 1867 treatise on diamonds and precious stones, Harry Emanuel writes the following:

[I]n the process of cutting, flaws and imperfections are often laid bare, which go much deeper than the appearance of the rough diamond would predict; and, on the other hand, the colour, apparent in the rough stone, is sometimes found to arise from the presence of flaws or specks, which are removed in cutting, thus leaving the stone white. (70)

From such a description, it is easy to see the parallel to the female condition, and particularly the female condition, as it is popularly portrayed in the mid-nineteenth century. With the emphasis on purity and hidden flaws, it is not difficult to understand why the diamond could hold such symbolic significance for the female wearer, by functioning as an indicator not only of personal wealth, but of moral worth. Trollope's The Eustace Diamonds (1871), a novel which can be said to revolve around this metaphor, is essentially a novel about worth: absolute vs. transitory worth, actual vs. symbolic worth, and especially monetary vs. moral worth. Lizzie's character, the legal issues surrounding the diamonds, and the convoluted marriage arrangements which are perpetuated by or affected by the presence of the diamonds are all, in one way or another, concerned with the different types of value – moral, symbolic, monetary, etc. – placed upon commodity objects: objects which, by their very nature, can never be permanently owned, as their value lies in their exchangeability. I will return later to a discussion of the diamonds themselves. There has been considerable recent commentary on the role of commodities – whatever their worth – and of commodity culture within Trollope's novel; such readings, however, concentrate on the purely symbolic role played by commodity objects – and primarily the diamonds – in the novel; it is worth, by contrast, examining how Trollope utilizes the discourses and associations of actual commodity objects as he deploys them within his fictional world. This paper will examine the ways in which Trollope uses four commodity objects in particular – books of poetry, hunting horses, the safe box, and finally, the Eustace diamonds themselves – and the contemporary discourses surrounding them to defend the essentially mercenary character of Lizzie as a woman shaped by the demands that a commodity-driven society places upon her.
“DREAMING OVER AN UNATTAINABLE END”: DISRAELI'S TANCRED AND THE FAILURE OF REFORM
Authors: Conary Jennifer
Published: February 2010

The “condition of England” in the middle of the nineteenth century was, for most Victorians (and is, indeed, for most modern scholars of the Victorian period), about as far removed from desert pirates and neo-Grecian queens as London from Jerusalem. But such was not the case in 1847 for the ambitious novelist-turned-politician Benjamin Disraeli, himself a mixture of political and social incongruities, who chose to conclude his political trilogy with a novel that bore greater resemblance to an Arabian Nights fantasy than to any mid-Victorian reform fiction. Contemporary readers of Tancred, or The New Crusade (1847) were understandably perplexed: “There is no principle of cohesion about the book, if we except the covers,” complained one reviewer (qtd. in Stewart 229). And, while critics have expanded upon this dismissive condemnation throughout the twentieth century, not much has changed regarding the general critical appraisal or thoughtful analysis of what Disraeli regarded as the favorite of his compositions (Blake 215). The least popular of the Young England novels both in its own day and in ours, Tancred has most frequently been viewed as an anomaly – an abandonment of the political manifesto Disraeli began in Coningsby and continued in Sybil.
MRS. SEACOLE PRESCRIBES HYBRIDITY: CONSTITUTIONAL AND MATERNAL RHETORIC INWONDERFUL ADVENTURES OF MRS. SEACOLE IN MANY LANDS
Authors: Howell Jessica
Published: February 2010

In an 1857Saturday Reviewarticleof the novelTwo Years Ago, T. C. Sanders characterizes Charles Kingsley's ideal man: he “fears God and can walk a thousand miles in a thousand hours – [he] breathes God's free air on God's rich earth, and at the same time can hit a woodcock, doctor a horse, and twist a poker around his fingers” (qtd. in Haley 108). Tom Thurnall, the fearless, constitutionally robust, well-traveled doctor and hero ofTwo Years Ago, fits these requirements. His physical strength also manifests itself as a charmed immunity to illness: during a cholera epidemic in Aberalva (a fictional Cornish town), “[Tom] thought nothing about death and danger at all . . . Sleep he got when he could, and food as often as he could; into the sea he leapt, morning and night, and came out fresher each time” (Kingsley,Years288). Charles Kingsley's own self-proclaimed medical and religious philosophies give clear insight intoTwo Years Ago'sintended effects. A sanitary reformer in the mould of Edwin Chadwick and Florence Nightingale, Kingsley felt that disease arose from crowding, filth, and poisonous vapors. Kingsley's contemporaries named his perspective “muscular Christianity,” recognizing that Kingsley “strong arms” his readers by inspiring in them fear and uncertainty about their own health practices and then shows them the way, with examples like Tom, to an active, devout lifestyle.
Preface
Authors: Larking Lambert B.
Published: February 2010

In a communication from Mr. Milward to the Archælogical Journal, December, 1850, the following statement occurs, with reference to the charters, &c. preserved in the Eecord Office at Malta.

“There is also a volume of the fifteenth century, containing the accounts of the Commanderies. It is a continuation of an older and still more interesting volume which has, by some means, found its way into the Public Library. The latter gives the accounts of the property belonging to the Order in England and Scotland. Unfortunately these accounts are very difficult to decipher. I remember, however, looking over it, in company with a Scotch gentleman, who had edited various antiquarian works, and with another gentleman from Northumberland. The Scotchman read the MS. with tolerable facility; my friend from the North repeatedly identified certain allusions with property that he knew, and felt much interest in the book. There is also much that is valuable in the statement of the different prices paid for commodities, labour, &c.”
ZEB1 and CtBP form a repressive complex at a distal promoter element of the BCL6 locus
Authors: Papadopoulou Vasiliki , Postigo Antonio , Sánchez-Tilló Ester , Porter Andrew C. G. , Wagner Simon D.
Published: February 2010

BCL6 is essential for normal antibody responses and is highly expressed in germinal centre B-cells. Constitutive expression due to chromosomal translocations or mutations of cis-acting regulatory elements contributes to diffuse large B-cell lymphoma. BCL6 expression is therefore tightly regulated in a lineage- and developmental-stage-specific manner, and disruption of normal controls can contribute to lymphomagenesis. In order to discover potential cis-acting control regions we carried out DNase I-hypersensitive site mapping. Gel-shift assays and chromatin immunoprecipitation of the core region of a hypersensitive site 4.4 kb upstream of BCL6 transcription initiation (HSS-4.4) showed an E-box element-binding ZEB1 (zinc finger E-boxbinding homeobox 1) and the co-repressor CtBP (C-terminal binding protein). As compared with peripheral blood B-cells, ZEB1, a two-handed zinc finger transcriptional repressor, is expressed at relatively low levels in germinal centre cells, whereas BCL6 has the opposite pattern of expression. Transfection of ZEB1 cDNA caused a reduction in BCL6 expression and a mutated ZEB1, incapable of binding CtBP, lacked this effect. siRNA (small interfering RNA)-mediated knockdown of ZEB1 or CtBP produced an increase in BCL6 mRNA. We propose that HSS-4.4 is a distal promoter element binding a repressive complex consisting of ZEB1 and CtBP. CtBP is ubiquitously expressed and the results of the present study suggest that regulation of ZEB1 is required for control of BCL6 expression.
Product Switching in the Pharmaceutical Industry: Ripe for Antitrust Scrutiny?
Authors: Silber Seth , Kuritz Kara
Published: February 2010

Since the Hatch-Waxman Act was enacted in 1984, generic drug companies have benefited from its provisions to facilitate approval of generic alternatives to brand-name pharmaceuticals. Upon generic entry, consumers of prescription drugs benefit from large discounts as brand manufacturers lose significant market share to these lower-priced alternatives. Over time, brand-name drug manufacturers have undertaken strategies, such as ‘product switching’ or ‘product hopping’, that may delay or prevent generic entry and protect their market share. Generic drug manufacturers, drug purchasers and antitrust authorities have begun looking to the antitrust laws to address these strategies and their impact on generic entry. This article discusses the regulatory framework under which pharmaceutical companies introduce new drugs, two prominent cases in which courts have wrestled with whether product switching violates the antitrust laws, factors that might support an antitrust claim for product switching, and the FTC's interest in challenging product switching.
Preliminary studies on space charge compensation by analyzing residual argon gas ion signals
Authors: Lu P. N. , Peng S. X. , Ren H. T. , Zhang M. , Yuan Z. X. , Song Z. Z. , Zhao J. , Yu J. X. , Ma Y. J. , Xu R. , Guo Z. Y.
Published: February 2010

An experimental method is related to research the space charge compensation (SCC) effect in low energy intense proton beams by analyzing residual gas (RG) ion signals. The signal curves were measured with an energy spectrometer under the RG pressure from 1.2×10−3 to 1.6×10−2 Pa. Most of the data showed a similar trend with our theoretical predicts. From the RG ion energy spectra the potential distribution in the beam was calculated both with and without the SCC effect. Moreover, as a preliminary result, a best compensating point is achieved for the low energy beam transport transmission of 40 KeV, 60 mA H+ beam in Peking University.
Achievement and improvement of the JT-60U negative ion source for JT-60 Super Advanced (invited)
Authors: Kojima A. , Hanada M. , Tanaka Y. , Inoue T. , Watanabe K. , Taniguchi M. , Kashiwagi M. , Umeda N. , Tobari H. , Grisham L. R. ,   JT-60 NBI Group
Published: February 2010

Developments of the large negative ion source have been progressed in the high-energy, high-power, and long-pulse neutral beam injector for JT-60 Super Advanced. Countermeasures have been studied and tested for critical issues of grid heat load and voltage holding capability. As for the heat load of the acceleration grids, direct interception of D− ions was reduced by adjusting the beamlet steering. As a result, the heat load was reduced below an allowable level for long-pulse injections. As for the voltage holding capability, local electric field was mitigated by tuning gap lengths between large-area acceleration grids in the accelerator. As a result, the voltage holding capability was improved up to the rated value of 500 kV. To investigate the voltage holding capability during beam acceleration, the beam acceleration test is ongoing with new extended gap.
Electron transport in copper phthalocyanines
Authors: Singh Samarendra P. , Sellinger Alan , Dodabalapur Ananth
Published: February 2010

Charge transport in copper phthalocyanine (CuPc), partially fluorinated CuPc (F4CuPc), and fluorinated CuPc (F16CuPc) based organic thin film transistors is studied using dual SiO2/polymethylmethacrylate gate dielectrics. We demonstrate the strong influence of air/moisture induced electron traps on electron transport when the lowest unoccupied molecular orbital is close to the vacuum irrespective of hydroxyl-free dielectrics used in the devices.
Pulsed terahertz time domain spectroscopy of vertically structured photoconductive antennas
Authors: Faulks R. , Rihani S. , Beere H. E. , Evans M. J. , Ritchie D. A. , Pepper M.
Published: February 2010

We present a terahertz (THz) photoconductive emitter structure, which employs a n-doped layer underneath a low-temperature-grown GaAs region to enable the THz transient to couple vertically through a defined mesa. A nonlinear bias dependence is observed, yielding an order in magnitude improvement in power for a mesa device with a 100 μm2 area over a conventional planar control reference device at 32 V and 5 mW illumination power. We relate the bias dependence of the THz signal to the breakdown voltage observed in the current-voltage characteristic. Reducing the antenna gap size through reducing the thickness of the low temperature-GaAs region below 1 μm shows a large improvement in the bandwidth of the device, with an enhancement of the normalized intensity between 0.2 to 2 THz for a bow-tie antenna geometry.
Mesoscopic nonequilibrium thermodynamics approach to non-Debye dielectric relaxation
Authors: Híjar Humberto , Méndez-Bermúdez J. G. , Santamaría-Holek Iván
Published: February 2010

Mesoscopic nonequilibrium thermodynamics is used to formulate a model describing nonhomogeneous and non-Debye dielectric relaxation. The model is presented in terms of a Fokker–Planck equation for the probability distribution of noninteracting polar molecules in contact with a heat bath and in the presence of an external time-dependent electric field. Memory effects are introduced in the Fokker–Planck description through integral relations containing memory kernels, which in turn are used to establish a connection with fractional Fokker–Planck descriptions. The model is developed in terms of the evolution equations for the first two moments of the distribution function. These equations are solved by following a perturbative method from which the expressions for the complex susceptibilities are obtained as a function of the frequency and the wave number. Different memory kernels are considered and used to compare with experiments of dielectric relaxation in glassy systems. For the case of Cole–Cole relaxation, we infer the distribution of relaxation times and its relation with an effective distribution of dipolar moments that can be attributed to different segmental motions of the polymer chains in a melt.
An electronic structure perspective on glass-forming ability in metallic glasses
Authors: Yu H. B. , Wang W. H. , Bai H. Y.
Published: February 2010

Through systematic study of glass-forming ability (GFA) and the electronic specific heat coefficient in typical ternary (Cu50Zr50)100−xAlx bulk metallic glasses, we provide compelling experimental evidence that the density of electronic energy states at the Fermi level indeed is closely correlated with the GFA of metallic glasses, and the best GFA can be obtained when the Fermi surfaces nearly touch the quasi-Brillouin boundaries, as predicted by the nearly free electron model. Our results highlight the significance of electronic structural effects on the formation of metallic glasses.
Theoretical and experimental studies of three-photon-induced excited-state absorption
Authors: Gu Bing , Ji Wei , Yang Hong-Zhi , Wang Hui-Tian
Published: February 2010

We theoretically and experimentally study excited-state absorption (ESA) induced by three-photon absorption (3PA) under the excitation of ultrafast laser pulses. Based on five-level rate-equation theory, we obtain an analytical expression for the effective four-photon absorption coefficient that originates from both singlet-singlet (S-S) and triplet-triplet (T-T) ESA. We validate that the T-T ESA could be justifiably neglected in the femtosecond regime. Experimentally, we verify it in acetone solution of 2,4,5-trimethoxychalcone by performing femtosecond Z-scan measurements; at low excitation intensity, only 3PA is determined; and under the excitation of high intensity, however, we observe the concurrence of 3PA and 3PA-induced S-S ESA processes.
Light-induced translocation of
Drosophila
visual Arrestin2 depends on Rac2
Authors: Elsaesser Rebecca , Kalra Deepak , Li Ruoxia , Montell Craig
Published: February 2010

Photoreceptor cells are remarkable in their ability to adjust their sensitivity to light over a wide range of intensities. Rapid termination of the photoresponse is achieved in part by shuttling proteins in and out of the light-transducing compartment of the photoreceptor cells. One protein that undergoes light-dependent translocation is the rhodopsin regulatory protein arrestin. However, the mechanisms coupling rhodopsin to arrestin movement are poorly understood. Here we show that light-dependent shuttling of the major arrestin in
Drosophila
photoreceptor cells, Arrestin2 (Arr2), occurs independently of known elements of the phototransduction cascade. Disruptions of the trimeric G protein, phospholipase Cβ, the TRP channel, or the Na
+
/Ca
2+
exchanger did not influence Arr2 localization. Rather, we found that loss of the small GTPase Rac2 severely impaired Arr2 movement and prolonged the termination of the photoresponse. Our findings demonstrate that light-induced translocation of Arr2 occurs through a noncanonical rhodopsin/Rac2 pathway, which is distinct from the classical phototransduction cascade.
Fluctuation enhanced electrochemical reaction rates at the nanoscale
Authors: García-Morales Vladimir , Krischer Katharina
Published: February 2010

The electrode potential constitutes a dynamical variable whenever an electrode is resistively coupled to the electric circuit. We show that at the nanoscale, the discreteness and stochasticity of an electron transfer event causes fluctuations of the electrode potential that render all elementary electrochemical reactions to be faster on a nanoelectrode than predicted by the macroscopic (Butler–Volmer) electrochemical kinetics. This phenomenon is substantiated by means of a generalized (electro)chemical master equation.
ParA2, aVibrio choleraechromosome partitioning protein, forms left-handed helical filaments on DNA
Authors: Hui Monica P. , Galkin Vitold E. , Yu Xiong , Stasiak Alicja Z. , Stasiak Andrzej , Waldor Matthew K. , Egelman Edward H.
Published: February 2010

Most bacterial chromosomes contain homologs of plasmid partitioning (par) loci. These loci encode ATPases called ParA that are thought to contribute to the mechanical force required for chromosome and plasmid segregation. InVibrio cholerae, the chromosome II (chrII)parlocus is essential for chrII segregation. Here, we found that purified ParA2 had ATPase activities comparable to other ParA homologs, but, unlike many other ParA homologs, did not form high molecular weight complexes in the presence of ATP alone. Instead, formation of high molecular weight ParA2 polymers required DNA. Electron microscopy and three-dimensional reconstruction revealed that ParA2 formed bipolar helical filaments on double-stranded DNA in a sequence-independent manner. These filaments had a distinct change in pitch when ParA2 was polymerized in the presence of ATP versus in the absence of a nucleotide cofactor. Fitting a crystal structure of a ParA protein into our filament reconstruction showed how a dimer of ParA2 binds the DNA. The filaments formed with ATP are left-handed, but surprisingly these filaments exert no topological changes on the right-handed B-DNA to which they are bound. The stoichiometry of binding is one dimer for every eight base pairs, and this determines the geometry of the ParA2 filaments with 4.4 dimers per 120 Å pitch left-handed turn. Our findings will be critical for understanding how ParA proteins function in plasmid and chromosome segregation.
Lymphoma endothelium preferentially expresses Tim-3 and facilitates the progression of lymphoma by mediating immune evasion
Authors: Huang Xiaoyuan , Bai Xiangyang , Cao Yang , Wu Jingyi , Huang Mei , Tang Duozhuang , Tao Si , Zhu Tao , Liu Yanling , Yang Yang , Zhou Xiaoxi , Zhao Yanxia , Wu Mingfu , Wei Juncheng , Wang Daowen , Xu Gang , Wang Shixuan , Ma Ding , Zhou Jianfeng
Published: February 2010

Angiogenesis is increasingly recognized as an important prognosticator associated with the progression of lymphoma and as an attractive target for novel modalities. We report a previously unrecognized mechanism by which lymphoma endothelium facilitates the growth and dissemination of lymphoma by interacting with circulated T cells and suppresses the activation of CD4+ T cells. Global gene expression profiles of microdissected endothelium from lymphoma and reactive lymph nodes revealed that T cell immunoglobulin and mucin domain–containing molecule 3 (Tim-3) was preferentially expressed in lymphoma-derived endothelial cells (ECs). Clinically, the level of Tim-3 in B cell lymphoma endothelium was closely correlated to both dissemination and poor prognosis. In vitro, Tim-3+ ECs modulated T cell response to lymphoma surrogate antigens by suppressing activation of CD4+ T lymphocytes through the activation of the interleukin-6–STAT3 pathway, inhibiting Th1 polarization, and providing protective immunity. In a lymphoma mouse model, Tim-3–expressing ECs promoted the onset, growth, and dissemination of lymphoma by inhibiting activation of CD4+ T cells and Th1 polarization. Our findings strongly argue that the lymphoma endothelium is not only a vessel system but also a functional barrier facilitating the establishment of lymphoma immune tolerance. These findings highlight a novel molecular mechanism that is a potential target for enhancing the efficacy of tumor immunotherapy and controlling metastatic diseases.
Household food security is associated with early childhood language development: results from a longitudinal study in rural Bangladesh
Authors: Saha K. K. , Tofail F. , Frongillo E. A. , Rasmussen K. M. , Arifeen S. E. , Persson L. Å. , Huda S. N. , Hamadani J. D.
Published: February 2010

Background  Although household food security (HHFS) has been linked to academic performance in school children, its association with early childhood development has received less attention, particularly in low‐income countries. We investigated the association of HHFS with subsequent language development of children at 18 months of age in rural Bangladesh.

Methods  We followed 1439 infants born in 2002–2003 to the mothers in Maternal and Infant Nutrition Intervention in Matlab study, a large intervention trial conducted in rural Bangladesh. A HHFS scale was created from data collected from mothers during pregnancy. At 18 months, children's language (expression and comprehension) development was assessed using a Bengali adaptation of MacArthur's Communicative Development Inventory which was based on mothers' report of their children's ability to comprehend and express words in different categories. General linear regression models were used to examine the association between HHFS and language development at 18 months of age adjusting for potential confounders.

Results  Household food security was associated with language comprehension (B = 0.19, 95% CI = 0.09, 0.30, P < 0.001) and expression (B = 1.01, 95% CI = 1.00, 1.02, P < 0.01) at 18 months of age. Mean language comprehension and expression at 18 months of the children in higher quartiles of HHFS were higher (P < 0.05) than those of the children in lower quartiles.

Conclusions  Household food security is positively associated with subsequent language development of rural Bangladeshi children. Early language development has been reported to predict later child development. Therefore, strategies to ensure HHFS status in Bangladesh and similar settings should be considered for optimum child development.
Wing development genes of the pea aphid and differential gene expression between winged and unwinged morphs
Authors: Brisson J. A. , Ishikawa A. , Miura T.
Published: February 2010

Little is known about when, how or even if the wing development gene network elucidated in Drosophila is deployed in direct‐developing insects. Here we identify the wing development genes (as determined in Drosophila) of the pea aphid (Acyrthosiphon pisum), which produces winged or unwinged adults in response to environmental cues. We find that the principal wing development genes studied in Drosophila are present in the aphid genome and that apterous and decapentaplegic exhibit duplications. We followed expression levels of 11 of these developmental genes at embryogenesis and across the nymphal instars. Six showed significant stage‐specific expression level effects and apterous1 exhibited significantly different expression levels between winged and unwinged morphs, suggesting this gene acts proximately to realize polyphenic development.
Comprehensive survey of developmental genes in the pea aphid, Acyrthosiphon pisum: frequent lineage‐specific duplications and losses of developmental genes
Authors: Shigenobu S. , Bickel R. D. , Brisson J. A. , Butts T. , Chang C‐c. , Christiaens O. , Davis G. K. , Duncan E. J. , Ferrier D. E. K. , Iga M. , Janssen R. , Lin G.‐W. , Lu H.‐L. , McGregor A. P. , Miura T. , Smagghe G. , Smith J. M. , Van Der Zee M. , Velarde R. A. , Wilson M. J. , Dearden P. K. , Stern D. L.
Published: February 2010

Aphids exhibit unique attributes, such as polyphenisms and specialized cells to house endosymbionts, that make them an interesting system for studies at the interface of ecology, evolution and development. Here we present a comprehensive characterization of the developmental genes in the pea aphid, Acyrthosiphon pisum, and compare our results to other sequenced insects. We investigated genes involved in fundamental developmental processes such as establishment of the body plan and organogenesis, focusing on transcription factors and components of signalling pathways. We found that most developmental genes were well conserved in the pea aphid, although many lineage‐specific gene duplications and gene losses have occurred in several gene families. In particular, genetic components of transforming growth factor beta (TGFβ) Wnt, JAK/STAT (Janus kinase/signal transducer and activator of transcription) and EGF (Epidermal Growth Factor) pathways appear to have been significantly modified in the pea aphid.
Testing for CHEK2 in the cancer genetics clinic: ready for prime time?
Authors: Narod SA
Published: February 2010

Narod SA. Testing for CHEK2 in the cancer genetics clinic: ready for prime time?

The 1100delC mutation of the CHEK2 gene was found to be a cause of breast cancer in 2002. The lifetime risk of breast cancer among women with a mutation and with a family history of breast cancer is approximately 25%. These women are good candidates for screening with MRI and for chemoprevention with tamoxifen. It is reasonable to test for this single mutation when women undergo testing for BRCA1 and BRCA2.