bluuebunny/crossref_metadata_2025 huggingface dataset:
Art. XIII.—Affinities of the Dialects of the Chepang and Kusundah Tribes of Nipál with those of the Hill Tribes of Arracan
Authors: Forbes C. J. F.
Published: March 2011

When investigating the ethnological and linguistic characteristics of the various tribes of the Himalayan and sub-Himalayan regions, Mr. B. H. Hodgson was, especially, struck by finding lingual affinities which led him to connect certain broken and degraded tribes near the western boundary of Nipál with the vigorous and comparatively civilized Bhotiya races.
Parsi ZoroastrianGarbāsandMonājāts
Authors: Russell J. R.
Published: March 2011

It is a strange circumstance, yet one immediately observable, that the Parsi community in India, so innovative and so energetically creative in many other respects, has failed to distinguish itself in the sphere of indigenous arts. In the acquisition of tastes and skills in European or hybrid pseudo-Persian architecture, in European-style portraiture, and in Classical music, the Parsis have been diligent, even as they long ago became eloquent masters of the English tongue. What of their arts can properly be called Zoroastrian?
A new view of medieval Persian history
Authors: Rogers J. M.
Published: March 2011

A conspicuous feature of Ottoman history from the sixteenth century onwards, or even of fifteenth-century Mamluk Egypt, is that the mass of surviving administrative documents, well complemented by European sources, makes it possible to apply a range of economic and social concepts to illuminate their economy and society. For Persia the documents are far fewer and, even where, as in seventeenth-century Iṣfahān, the extant Safavid documents are exceptionally well complemented by European source material, doubts, often of a Marxian or Braudelian order, on the legitimacy of applying European concepts to Persian society are often entertained. In other periods the paucity of material is compounded by ethnic diversity – tribal versus settled populations; Turks versus Iranians or Iranians versus Turco-Mongols, all with deeply rooted authentic traditions – which is rarely documented, let alone explained, by the contemporary historians. It is almost as if the right kind of anthropologist could do more than the historian to exploit what material there is.
Notes on the Bahapur version of Aśoka's minor rock edict
Authors: Norman K. R.
Published: March 2011

THE EDITORS OF THE version of Aśoka's first Minor Rock Edict discovered at Bahapur deserve our thanks for making this inscription available so quickly.1 It is unfortunate that by some error the conventional symbols for a doubtful reading [ ], e.g. [sā]tileke in line 2, and a suggested emendation ( ), e.g. (ā)hā for ahā in line 1, have all been printed as [ ], but a careful examination of the photographs of the rock and of the estampage enables most ambiguities arising from this error to be eliminated.

There are several points in the Bahapur version which merit attention, (a) By a faulty word-division the editors have printed amha maye in line 3, presumably understanding amha as an ablative form. It is clear from the other versions of the edict that we must have am here, cf. yam in line 2. If we adopt the word-division am hamaye, we obtain a hitherto unattested form of the instrumental of the first person pronoun. In line 2 of the Calcutta-Bairat2 inscription we find hamā as the equivalent of mamā (= genitive), which is found in lines 13 and 16 of RE3 V at Kalsi, lines 5 and 12 of SepE I and line 6 of SepE II at Dhauli, and line 12 of PE IV at Delhi-Topra; in line 3 of the Calcutta-Bairat inscription we find hamiyāye as the equivalent of mamiyāye (= instrumental), which is found in line 6 of SepE II at Jaugada; we now have hamaye as the equivalent of mamaye (= instrumental), which is found in line 4 of SepE II at Dhauli.
Arabic Musical Manuscripts in the Bodleian Library
Authors: Farmer Henry George
Published: March 2011

Whilst engaged as a Research Student on “Mediaeval Arabian Musical Theory ” at Glasgow University, I had the good fortune to have access to several libraries, and among them the Bodleian, where I compiled for my needs a short but detailed catalogue of the Arabic musical MSS. in this famous library. As this catalogue may be of use to orientalists and musical antiquaries, I take this opportunity of giving it publicity.
XIX. Studies in Ancient Indian Medicine V.—The Composition of the Caraka Samhita in the Light of the Bower Manuscript
Authors: Hoernle A. F. Rudolph
Published: March 2011

In a previous contribution (No. IV, in this Journal for 1908, pp. 997 ff.), discussing Dṛiḍhabala's share in the composition of the Caraka Saṁhitā, I had indicated (ib., pp. 1017–18) what appeared to be conclusive evidence of the truth of one of the two traditional serial orders of the chapters of its Cikitsita Sthāna. That was the order which is shown in column 2 of the Table (ib., p. 1000), and which is adopted by Gangādhar in his well-known Berhampur edition of the Saṁhitā.
XXI. Ancient Historical Edicts at Lhasa
Authors: Waddell L. A.
Published: March 2011

Hitherto our authentic knowledge of the early history of Tibet has been derived, with one solitary exception, not from any records in the country itself, but solely from the references, contemporary and otherwise, embedded in the imperial chronicles of China, which have been rendered accessible to English students through the excellent translations of Dr. Bushell and Mr. Rockhill. The one indigenous early record we have possessed is the imprint of the treaty edict of “822 A.D. with the Emperor Mu Tsung”, which Dr. Bushell procured at Peking and published in this Journal in 1880. That edict, however, though affording an interesting side-glimpse into the state of civilization in Tibet at that period, and incidentally confirming the Chinese accounts, yielded few important historical data; and no other local source of trustworthy early history has been forthcoming. For the Tibetans, unlike the Chinese, are notably deficient in the true historical sense.
XXIV. The Last Words of Asoka
Authors: Fleet J. F.
Published: March 2011

We could hardly fail to read with interest and close attention Professor Hultzsch's note, published at p. 728 above, on the Rūpnāth recension of the Last Edict of Aśōka: particularly because his views are calculated to be completely subversive of the chronological arrangement laid out by me at p. 27 above, and to require us to find an entirely new date for the death of Buddha. Accepting what is plain, that the figures 256 are a date, he has revived the view that they mark the number of years elapsed since the renunciation of Buddha, when he left his home and went forth as a wandering ascetic mendicant into the houseless state, in the search for true knowledge.
XXVI. Notes on Archæological Exploration in India, 1908–9
Authors: Marshall J. H.
Published: March 2011

In reviewing the discoveries that have been made by the Archæological Department in India during the year 1908–9, I propose to start with one of unique historical interest—the only lithic record that has yet been found in which reference is made to the Indo-Greek rulers of the Panjab.
XXVIII. The Besnagar Inscription B
Authors: Barnett L. D.
Published: March 2011

I Read the two lines of this inscription, illustrated in the plate at p. 1054 above, thus:—

Trīni(triṃni ?) amutapadāni [kā]le(?) anuṭhitāni neyā ti v[uttaṃ?] damaṃ cāga apramādo.

Neyā is probably the Sanskrit jñeyāt. Amutapadāni and cāga stand for the Sanskrit amṛitapadāni and tyāga. Anuṭhitāni (i.e. anuṭṭh°) is the Sanskrit anuṣṭhitāni.
Global Governance of Hazardous Chemicals: Challenges of Multilevel Management. By Henrik Selin
Authors: Mullin Megan
Published: March 2011

Global Governance of Hazardous Chemicals: Challenges of Multilevel Management. By Henrik Selin. Cambridge, MA: MIT Press, 2010. 235p. $44.00 cloth, $22.00 paper.

In his book, Henrik Selin introduces readers to the complex and fragmented international regime governing the management of hazardous chemicals. He presents a compelling account of the environmental and human health threats posed by international trade and the transboundary movement of hazardous chemicals and waste, building a strong case for this problem as an appropriate target for international cooperation and governance. He then analyzes the development and contents of the chemicals regime, with particular emphasis on the way that linkages among issues and actors contribute to the design of chemicals management policy.
Response to Henrik Selin's review ofGoverning the Tap: Special District Governance and the New Local Politics of Water
Authors: Mullin Megan
Published: March 2011

In his careful and generous review of my book, Henrik Selin asks why I selected responsiveness and intergovernmental coordination as dependent variables for my analysis, therefore setting aside other policy effects that special district governance might produce. This is an important question: the delegation of policy authority to autonomous, specialized governments is a significant departure from the normal politics that takes place in a multidimensional legislature and could have a variety of consequences. To the extent that special districts have received any scholarly attention, it has focused mostly on estimating how specialization affects the level of public spending. My interest lies more in the quality of governance. What do we want from representative government? Central among our goals should be policy outcomes that are responsive both to public preferences and to public problems.
Response to Thomas Princen's review of Vibrant Matter: A Political Ecology of Things
Authors: Bennett Jane
Published: March 2011

Tom Princen and I share many commitments—to treading lightly on the earth, to the political potential of everyday habits, to practicing the difficult art of countercultural persuasion, to a political economy of sustainability, and to the advantages of short and earnest books.
The Relationship of Leadership Quality to the Political Presence of Civic Associations
Authors: Han Hahrie , Andrews Kenneth T. , Ganz Marshall , Baggetta Matthew , Lim Chaeyoon
Published: March 2011

Member-based civic associations, or citizen groups, have two crucial roles in American democracy. They advocate for members' interests in the public arena, but also operate as Tocquevillian “schools of democracy” linking citizens to politics and equipping them with the skills of democratic citizenship. Yet scant research has examined the interrelationships of these two roles. Does the work that civic associations do in developing democratic participants enhance the work they do advocating for members' interests in the public arena? We bring together two previously disparate strands of research on civic associations by arguing that a key factor affecting the political presence of civic associations is leadership quality. We focus on the relationship of leadership quality to political presence, using data from a unique 2003 study of 226 local entities of the Sierra Club. We show that organizations with more skilled and committed leaders have higher levels of political presence. This contrasts with previous research that has focused primarily on community context and resources as explanatory factors. This study shows that political presence is related to the extent to which leaders develop their skills and demonstrate commitment to the organization.
Neogene to Quaternary broken foreland formation and sedimentation dynamics in the Andes of NW Argentina (25°S)
Authors: Hain M. P. , Strecker M. R. , Bookhagen B. , Alonso R. N. , Pingel H. , Schmitt A. K.
Published: March 2011

The northwest Argentine Andes constitute a premier natural laboratory to assess the complex interactions between isolated uplifts, orographic precipitation gradients, and related erosion and sedimentation patterns. Here we present new stratigraphic observations and age information from intermontane basin sediments to elucidate the Neogene to Quaternary shortening history and associated sediment dynamics of the broken Salta foreland. This part of the Andean orogen, which comprises an array of basement‐cored range uplifts, is located at ∼25°S and lies to the east of the arid intraorogenic Altiplano/Puna plateau. In the Salta foreland, spatially and temporally disparate range uplift along steeply dipping inherited faults has resulted in foreland compartmentalization with steep basin‐to‐basin precipitation gradients. Sediment architecture and facies associations record a three‐phase (∼10, ∼5, and <2 Ma), east directed, yet unsystematic evolution of shortening, foreland fragmentation, and ensuing changes in precipitation and sediment transport. The provenance signatures of these deposits reflect the trapping of sediments in the intermontane basins of the Andean hinterland, as well as the evolution of a severed fluvial network. Present‐day moisture supply to the hinterland is determined by range relief and basin elevation. The conspiring effects of range uplift and low rainfall help the entrapment and long‐term storage of sediments, ultimately raising basin elevation in the hinterland, which may amplify aridification in the orogen interior.
Future Developments in Modeling and Monitoring of Volcanic Ash Clouds
Authors: Bonadonna Costanza , Folch Arnau , Loughlin Sue
Published: March 2011

IAVCEI‐WMO Workshop on Ash Dispersal Forecast and Civil Aviation; Geneva, Switzerland, 18–20 October 2010; The April–May 2010 Eyjafjallajökull eruption brought to light the harmful effects of volcanic ash on civil aviation and the importance of robust ash forecasting based on the combination of numerical weather prediction (NWP), volcanic ash transport and dispersal models (VATDMs), and data acquisition. The Workshop on Ash Dispersal Forecast and Civil Aviation has produced a consensual document describing the characteristics and range of application of different VATDMs, identifying the needs of the modeling community, investigating new data acquisition strategies, and discussing how to improve communication between the volcanology community and operational agencies. The workshop was held at the World Meteorological Organization's (WMO) Geneva headquarters under the sponsorship of the Faculty of Sciences of the University of Geneva, the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI), and the canton of Geneva and was organized by scientists from the University of Geneva (Switzerland), the Barcelona Supercomputing Center (Spain), the Aeronautical Meteorology Division of the WMO, and the British Geological Survey (United Kingdom). Fifty‐two volcanologists, meteorologists, atmospheric dispersion modelers, and space‐ and ground‐based monitoring specialists from 12 different countries were gathered (attendance was by invitation only), including representatives from six Volcanic Ash Advisory Centers (VAACs) and related institutions.
Media Fellow Journeys to the “Other Side”
Authors: Weiss Marissa
Published: March 2011

On the heels of defending my Ph.D. in soil ecology, I headed off to northern Colorado last September for the next step in my scientific journey: working at a radio station. AGU was sponsoring me as a mass media fellow, a scientist‐reporter temporarily working at a news media outlet. In graduate school I had pursued some science writing training, but I had never been employed as a journalist. I hoped the experience would help me understand why it can be hard for scientists and journalists to communicate with each other and what the barriers are to providing accurate and comprehensive coverage of science in the media. That's the kind of understanding that the fellowship program, run by the American Association for the Advancement of Science, was meant to promote. It helps scientists learn from experience about how science reporting is done, and in an age when science desks have been eliminated by most major news outlets, it puts an eye on science back in the newsroom.
Gaussian channel in a quantum information network
Authors: Liu Guo , Qiao Bi , Ruda H. E.
Published: March 2011

Starting from the quantum Fokker–Planck equation, a viable quantum Gaussian channel is constructed in a quantum information network. It is shown that the solution of this equation satisfies a Gaussian distribution channel. Transforming the solution of the Fokker–Planck equation and substituting it into the information formula, a quantum dynamical mutual information equation is obtained in the coherent state representation. On the basis of this equation, a new scheme is proposed to implement parallel quantum information processing in the quantum Gaussian channel. The proposed scheme takes the coefficients related to the encryption states of photons as the signal, and encodes the information that will be passed in the quantum Gaussian channel from the input terminal. Information is then accessed by extracting and decoding the coefficients from the output terminal. Compared with a classical Gaussian channel, this approach offers the advantage of quantum parallelism.
Studies of concentration dependences in the luminescence of Ti-doped Al2O3
Authors: Mikhailik V. B. , Di Stefano P. C. F. , Henry S. , Kraus H. , Lynch A. , Tsybulskyi V. , Verdier M. A.
Published: March 2011

The variation of luminescence and excitation spectra of titanium doped Al2O3 for the concentration of Ti ranging from 10 to 1000 ppm was investigated using synchrotron radiation. In the lightly doped Al2O3–Ti (<100 ppm) samples we identified several emission bands. These are the emission of the excitons localized at Ti (290 nm), the emission due to F+ centers (325 nm), the band around 420 nm traditionally attributed to F center emission, and the luminescence of Ti3+ ions at 720 nm. The emphasis in this study is on the clarification of the nature of the blue emission band in the samples with high concentration of Ti (≥100 ppm), where the luminescence and excitation spectra of the blue emission exhibit noticeable variability. This is explained by a model of the luminescence process of Ti4+–F centers that includes the photoionization of Ti3+, the subsequent capture of electrons at F+-centers, formation of excited F-centers and, finally, the emission of a blue photon. The quenching of the blue emission with increasing Ti concentration is interpreted in terms of competition between oxygen vacancies and Ti4+ centers in the capture of the electron.
Lost in reciprocal space? Determination of the scattering condition in spot profile analysis low-energy electron diffraction
Authors: Klein C. , Nabbefeld T. , Hattab H. , Meyer D. , Jnawali G. , Kammler M. , zu Heringdorf F.-J. Meyer , Golla-Franz A. , Müller B. H. , Schmidt Th. , Henzler M. , Horn-von Hoegen M.
Published: March 2011

The precise knowledge of the diffraction condition, i.e., the angle of incidence and electron energy, is crucial for the study of surface morphology through spot profile analysis low-energy electron diffraction (LEED). We demonstrate four different procedures to determine the diffraction condition: employing the distortion of the LEED pattern under large angles of incidence, the layer-by-layer growth oscillations during homoepitaxial growth, a G(S) analysis of a rough surface, and the intersection of facet rods with 3D Bragg conditions.
Possible formation of a self-localized state of quasi-one-dimensional surface electrons in dense helium vapor
Authors: Nikolaenko V. A. , Smorodin A. V. , Sokolov S. S.
Published: March 2011

The mobility of surface electrons in quasi-one-dimensional conducting channels above liquid helium is studied experimentally at temperatures of 1.5–3K. It is found that for T>2K the mobility falls off sharply compared to the levels corresponding to kinetic mobility of the electrons. This behavior of the mobility can be explained by the formation of a self-localized electron state in the dense helium vapor accompanied by the appearance of a macroscopic region with a nonuniform distribution of the gas density surrounding an electron. Theoretical estimates of the temperature for formation of the self-localized state based on analyzing the conditions for a minimum free energy of the system are close to the experimental results.
Interfacial properties and morphologies of graphene-graphane composite sheets
Authors: Reddy C. D. , Cheng Q. H. , Shenoy V. B. , Zhang Y. W.
Published: March 2011

The interfaces between graphene and graphane play an important role in developing graphene-graphane-based electronic devices. We identify three most common types of graphane-graphene interface, and perform atomistic simulations to determine three key parameters that characterize the interface structural properties: mismatch strain, tilt angle, and interfacial stress. Further through atomistic simulations, we find that the composite sheets can develop complex morphologies, such as ripples, warps and wedges. These morphologies can be accurately reproduced by our finite-element modeling with interfacial properties explicitly included. We further show that mismatch in the lattice parameters between graphene and graphane is the dominant factor that causes the complex morphologies. Our work provides a quantitative framework for analyzing and designing graphene-graphane composite sheet architectures, and further for exploring their electronic properties.
Excitation localization effects in nanoscale molecular clusters (J-aggregates)
Authors: Yefimova S. L. , Sorokin A. V. , Katrunov I. K. , Malyukin Yu. V.
Published: March 2011

An analysis of experimental data from low-temperature selective spectroscopy and single J-aggregate spectroscopy reveals a hierarchy of exciton states within the confines of the absorption band of J-aggregates which are formed by relaxation of an excited state. For J-aggregates, which are characterized by substantial static disorder, strongly localized excitons are found in the long-wavelength edge of the absorption band; they have a discrete energy spectrum and jump mobility, and are not subject to strong relaxation. Delocalized (spatially extended) excitons are excited within the absorption band of the J-aggregates, except at its long-wavelength edge. They are characterized by coherent exciton transport and are the source of self-localized excitons.
Numerical investigations of lift suppression by feedback rotary oscillation of circular cylinder at low Reynolds number
Authors: Lu Lin , Qin Jian-Min , Teng Bin , Li Yu-Cheng
Published: March 2011

This article describes a strategy of active flow control for lift force reduction of circular cylinder subjected to uniform flow at low Reynolds numbers. The flow control is realized by rotationally oscillating the circular cylinder about its axis with ω(t)=−λCL(t), where ω(t) is the dimensionless angular speed of rotation cylinder, λ is the control parameter and CL(t) is the feedback signal of lift coefficient. The study focuses on seeking optimum λ for the low Reynolds numbers of 60, 80, 100, 150, and 200. The effectiveness of the proposed flow control in suppressing lift force is examined comprehensively by a numerical model based on the finite element solution of two-dimensional Navier–Stokes equations. The dependence of lift reduction on the control parameter λ is investigated. The threshold of λ, denoted by λc, is identified for the Reynolds numbers considered in this work. The numerical results show that the present active rotary oscillation of circular cylinder is able to reduce the amplitude of lift force significantly as long as λ≤λc, at least 50% for the laminar flow regime. Meanwhile, the present active flow control does not result in the undesirable increase in the drag force. The Strouhal number is observed to decrease slightly with the increase of λ. As for a specific Reynolds number, the larger λ gives rise to the larger amount of lift reduction. The lift reduction reaches the maximum at λ=λc. The mechanism behind the present lift reduction method is revealed by comparing the flow patterns and pressure distributions near the active rotationally oscillating circular cylinder and the stationary circular cylinder. It is found that the critical value λc generally increases with Reynolds number. Two types of lift shift are observed in the numerical results for the cases with λ>λc. The first is characterized by the regular fluctuation of lift coefficient but with nonzero mean value, while the second is associated with the sustaining increase of lift coefficient. The phenomenon of lift shift is found to be related closely to the evolution of vortex pattern in the near wake of circular cylinder.
Experimental control of vortex breakdown by density effects
Authors: Ismadi Mohd-Zulhilmi Paiz , Meunier Patrice , Fouras Andreas , Hourigan Kerry
Published: March 2011

The vortex breakdown inside a cylinder with a rotating top lid is controlled experimentally by injecting at the bottom a fluid with a small density difference. The density difference is obtained by mixing a heavy dye or alcohol with water in order to create a jet denser or lighter than water. The injection of a heavy fluid creates a buoyancy force downward, which counteracts the meridional recirculation in the cylinder and thus enhances the formation of a vortex breakdown bubble. The stability diagram shows that even a very small density difference of 0.02% is able to decrease by a factor of 2 the critical Reynolds number of appearance of the breakdown. On the other hand, the injection of a lighter fluid does not destroy the vortex breakdown. However, for large enough density differences (larger than 0.03%), the lighter fluid is able to pierce through the bubble and leads to a new structure of the vortex breakdown. Finally, a parallel is drawn between a light jet and a vortex ring generated at the bottom of the cylinder: strong vortex rings are able to pierce through the bubble, whereas weak vortex rings are simply advected around the bubble.
Pure spin thermoelectric generator based on a rashba quantum dot molecule
Authors: Liu Yu-Shen , Chi Feng , Yang Xi-Feng , Feng Jin-Fu
Published: March 2011

We propose a pure thermoelectric spin generator based on a Rashba quantum dot molecular junction by using the temperature difference instead of the usual voltage bias difference. A magnetic flux penetrating through the device is also considered. The spin Seebeck coefficient SS and the spin figure of merit ZST of the molecular junction are calculated in terms of the Green’s function formalism and the equation of motion (EOM) technique. It is found that a pure spin-up (spin-down) Seebeck coefficient can be generated by the coaction of the magnetic flux and the Rashba spin-orbit (RSO) interaction.
Interaction of hydrogen with carbon in multicrystalline Si solar-cell materials
Authors: Peng Chao , Zhang Haoxiang , Stavola Michael , Yelundur Vijay , Rohatgi Ajeet , Carnel Lode , Seacrist Mike , Kalejs Juris
Published: March 2011

Hydrogen is commonly introduced into silicon solar cells to reduce the deleterious effects of defects and to increase cell efficiency. When hydrogen is introduced into multicrystalline Si that is often used for the fabrication of solar cells, the H atoms can become trapped by carbon impurities to produce defect structures known at H2*(C). These defects act as both a source and a sink for hydrogen in H-related defect reactions. IR spectroscopy has been used to determine what H- and C-related defects are formed in multicrystalline Si when the carbon concentration is varied. A process that is used by industry to introduce hydrogen into Si solar cells is the postdeposition annealing of a hydrogen-rich SiNx layer. The H2*(C) defects provide a strategy for estimating the concentration and penetration depth of the hydrogen that is introduced by this method.
Excellent biocompatibility of semiconductor quantum dots encased in multifunctional poly(N-isopropylacrylamide) nanoreservoirs and nuclear specific labeling of growing neurons
Authors: GhoshMitra Somesree , Diercks David R. , Mills Nathaniel C. , Hynds DiAnna L. , Ghosh Santaneel
Published: March 2011

Quantum dots (QDs) have received attention for labeling biomolecules; however, toxicity of these nanostructures in the intracellular environment has prevented a biomedical breakthrough. Here we report biocompatibility of a QD based multifunctional system on neuronal cells. Moreover, the designed nanostructures bind with high affinity in the cell nucleus. Nucleus specific binding and enhanced biocompatibility, coupled with no deleterious effects on neurite outgrowth, even at high dosages (500 μg/ml sphere conc.) suggest increased therapeutic potential of this system for specific targeting followed by controlled release of drugs in treating neurodegenerative disorders.
Global dissipative solutions of a modified two-component Camassa–Holm shallow water system
Authors: Tan Wenke , Yin Zhaoyang
Published: March 2011

By introducing a new set of independent variables, we first transform a modified two-component Camassa–Holm shallow water system into a semilinear system. To obtain a dissipative solution, we modify the corresponding system into a discontinuous system. Then we map the solution of system to the dissipative solution of original equation. Moreover we prove that these global dissipative solutions construct a semigroup.
Reduction of magnetostatic interactions in self-organized arrays of nickel nanowires using atomic layer deposition
Authors: Da Col S. , Darques M. , Fruchart O. , Cagnon L.
Published: March 2011

Ordered arrays of magnetic nanowires are commonly synthesized by electrodeposition in nanoporous alumina templates. Due to their dense packing, strong magnetostatic interactions prevent the manipulation of wires individually. Using atomic layer deposition we reduce the diameter of the pores prior to electrodeposition. This reduces magnetostatic interactions, yielding fully remanent hysteresis loops. This is a first step toward the use of such arrays for magnetic racetrack memories.
Thermodynamics of d-dimensional hard sphere fluids confined to micropores
Authors: Kim Hyungjun , Goddard William A. , Han Kyeong Hwan , Kim Changho , Lee Eok Kyun , Talkner Peter , Hänggi Peter
Published: March 2011

We derive an analytical expression of the second virial coefficient of d-dimensional hard sphere fluids confined to slit pores by applying Speedy and Reiss’ interpretation of cavity space. We confirm that this coefficient is identical to the one obtained from the Mayer cluster expansion up to second order with respect to fugacity. The key step of both approaches is to evaluate either the surface area or the volume of the d-dimensional exclusion sphere confined to a slit pore. We, further, present an analytical form of thermodynamic functions such as entropy and pressure tensor as a function of the size of the slit pore. Molecular dynamics simulations are performed for d = 2 and d = 3, and the results are compared with analytically obtained equations of state. They agree satisfactorily in the low density regime, and, for given density, the agreement of the results becomes excellent as the width of the slit pore gets smaller, because the higher order virial coefficients become unimportant.
Quantitative effective atomic number imaging using simultaneous x-ray absorption and phase shift measurement
Authors: Mukaide Taihei , Watanabe Masatoshi , Takada Kazuhiro , Iida Atsuo , Fukuda Kazunori , Noma Takashi
Published: March 2011

A scanning type x-ray imaging system which measures the absorption and differential phase shift in a material quantitatively and simultaneously has been developed. The absorption and differential phase are used to obtain the effective atomic number of organic material samples which closely reflects their chemical composition. An effective atomic number map of polymer fibers has been obtained. The experimentally obtained effective atomic numbers of these polymers agree well with the corresponding calculated values.
Total reflection and transmission by epsilon-near-zero metamaterials with defects
Authors: Xu Yadong , Chen Huanyang
Published: March 2011

In this work, we investigate wave transmission through an epsilon-near-zero metamaterial waveguide embedded with defects. We show that by adjusting the geometric sizes and material properties of the defects, total reflection, and even transmission can be obtained, despite the impedance mismatch of epsilon-near-zero material with free space. Our work can greatly simplify the design of zero-index material waveguide applications by removing the dependence on permeability.
Local stoichiometry in amorphous supramolecular composites analyzed by solid-state C13 nuclear magnetic resonance
Authors: Kaji Hironori , Hayashi Hironobu , Yamada Tomonori , Fukuchi Masashi , Fujimura Subaru , Ueda Masahiro , Kang Soonchul , Umeyama Tomokazu , Matano Yoshihiro , Imahori Hiroshi
Published: March 2011

Solid-state nuclear magnetic resonance (NMR) has been applied to “amorphous” active layers consisting of donor-acceptor self-assembled composites in organic solar cells. Several stoichiometric supramolecular complexation states as well as the charge-transfer states are revealed by the solid-state NMR, which have been difficult to access by conventional spectroscopy. The spectra show clear correlation between local self-assembled supramolecular structures and the organic solar cell performances.
Third harmonic generation at 223 nm in the metallic regime of GaP
Authors: Roppo V. , Foreman J. V. , Akozbek N. , Vincenti M. A. , Scalora M.
Published: March 2011

We demonstrate second and third harmonic generation from a GaP substrate 500 μm thick. The second harmonic field is tuned at the absorption resonance at 335 nm, and the third harmonic signal is tuned at 223 nm, in a range where the dielectric function is negative. These results show that a phase locking mechanism that triggers transparency at the harmonic wavelengths persists regardless of the dispersive properties of the medium, and that the fields propagate hundreds of microns without being absorbed even when the harmonics are tuned to portions of the spectrum that display metallic behavior.
Effect of annealing on the microstructure and optical properties of ZnO/V2O5 composite
Authors: Zou C. W. , Yan X. D. , Chen R. Q. , Wu Z. Y. , Alyamani A. , Gao W.
Published: March 2011

Vanadium pentoxide (V2O5) films capped with a thin ZnO layer were prepared by magnetron sputtering at room temperature. The effect of annealing on the microstructure and optical properties of films was systematically investigated. Results indicated that the initially smooth films transformed to porous composite nanocrystals at 500 °C and then further to agglomerated nanoslices at 550 °C. This microstructure transformation is attributed to the distinct temperature-sensitive crystallization of V2O5. The annealed films exhibited enhanced visible photoluminescence, which was attributed to the coupling between V2O5 nanorods and ZnO nanoparticles as well as the improved V2O5 crystallinity.
Raman scattering in InAs/AlGaAs quantum dot nanostructures
Authors: Giulotto E. , Geddo M. , Grandi M. S. , Guizzetti G. , Trevisi G. , Seravalli L. , Frigeri P. , Franchi S.
Published: March 2011

We report on Raman scattering experiments on InAs/AlxGa1−xAs quantum dot heterostructures with 0≤x≤0.6. The samples were prepared by using molecular beam epitaxy (MBE) and atomic layer MBE for the growth of different layers. For x>0, we detected several lines originating from the AlxGa1−xAs alloy. These can be related to scattering from GaAs-like and AlAs-like phonons with q≅0, and weaker scattering from disorder-activated phonons with q≠0. In particular, we identified a line at ∼250 cm−1 as due to disorder-activated longitudinal optical phonons in the alloy. This conclusion is different than the attribution of this line to scattering from dots and, consequently, we do not recognize the possibility of deriving any information about the actual composition of the dots from an analysis of this line as proposed by other authors.
Chirality and thickness-dependent thermal conductivity of few-layer graphene: A molecular dynamics study
Authors: Zhong Wei-Rong , Zhang Mao-Ping , Ai Bao-Quan , Zheng Dong-Qin
Published: March 2011

The thermal conductivity of graphene nanoribbons (layer from 1 to 8 atomic planes) is investigated by using the nonequilibrium molecular dynamics method. We present that the room-temperature thermal conductivity decays monotonically with the number of the layers in few-layer graphene. The superiority of zigzag graphene in thermal conductivity is only available in high temperature region and disappears in multilayer case. It is explained that the phonon spectral shrink in high frequency induces the change in thermal conductivity. It is also reported that single-layer graphene has better ballistic transport property than the multilayer graphene.
Addiction: Beyond dopamine reward circuitry
Authors: Volkow Nora D. , Wang Gene-Jack , Fowler Joanna S. , Tomasi Dardo , Telang Frank
Published: March 2011

Dopamine (DA) is considered crucial for the rewarding effects of drugs of abuse, but its role in addiction is much less clear. This review focuses on studies that used PET to characterize the brain DA system in addicted subjects. These studies have corroborated in humans the relevance of drug-induced fast DA increases in striatum [including nucleus accumbens (NAc)] in their rewarding effects but have unexpectedly shown that in addicted subjects, drug-induced DA increases (as well as their subjective reinforcing effects) are markedly blunted compared with controls. In contrast, addicted subjects show significant DA increases in striatum in response to drug-conditioned cues that are associated with self-reports of drug craving and appear to be of a greater magnitude than the DA responses to the drug. We postulate that the discrepancy between the expectation for the drug effects (conditioned responses) and the blunted pharmacological effects maintains drug taking in an attempt to achieve the expected reward. Also, whether tested during early or protracted withdrawal, addicted subjects show lower levels of D2 receptors in striatum (including NAc), which are associated with decreases in baseline activity in frontal brain regions implicated in salience attribution (orbitofrontal cortex) and inhibitory control (anterior cingulate gyrus), whose disruption results in compulsivity and impulsivity. These results point to an imbalance between dopaminergic circuits that underlie reward and conditioning and those that underlie executive function (emotional control and decision making), which we postulate contributes to the compulsive drug use and loss of control in addiction.
More closely related species are more ecologically similar in an experimental test
Authors: Burns Jean H. , Strauss Sharon Y.
Published: March 2011

The relationship between phylogenetic distance and ecological similarity is key to understanding mechanisms of community assembly, a central goal of ecology. The field of community phylogenetics uses phylogenetic information to infer mechanisms of community assembly; we explore, the underlying relationship between phylogenetic similarity and the niche. We combined a field experiment using 32 native plant species with a molecular phylogeny and found that closely related plant species shared similar germination and early survival niches. Species also competed more with close relatives than with distant relatives in field soils; however, in potting soil this pattern reversed, and close relatives might even have more mutalistic relationships than distant relatives in these soils. Our results suggest that niche conservatism (habitat filtering) and species interactions (competition or facilitation) structure community composition, that phylogenetic relationships influence the strength of species’ interactions, and that conserved aspects of plant niches include soil attributes.
Experimental verification of the rainbow trapping effect in adiabatic plasmonic gratings
Authors: Gan Qiaoqiang , Gao Yongkang , Wagner Kyle , Vezenov Dmitri , Ding Yujie J. , Bartoli Filbert J.
Published: March 2011

We report the experimental observation of a trapped rainbow in adiabatically graded metallic gratings, designed to validate theoretical predictions for this unique plasmonic structure. One-dimensional graded nanogratings were fabricated and their surface dispersion properties tailored by varying the grating groove depth, whose dimensions were confirmed by atomic force microscopy. Tunable plasmonic bandgaps were observed experimentally, and direct optical measurements on graded grating structures show that light of different wavelengths in the 500–700-nm region is “trapped” at different positions along the grating, consistent with computer simulations, thus verifying the “rainbow” trapping effect.
Interaction between hypothalamic dorsomedial nucleus and the suprachiasmatic nucleus determines intensity of food anticipatory behavior
Authors: Acosta-Galvan Guadalupe , Yi Chun-Xia , van der Vliet Jan , Jhamandas Jack H. , Panula Pertti , Angeles-Castellanos Manuel , del Carmen Basualdo María , Escobar Carolina , Buijs Ruud M.
Published: March 2011

Food anticipatory behavior (FAA) is induced by limiting access to food for a few hours daily. Animals anticipate this scheduled meal event even without the suprachiasmatic nucleus (SCN), the biological clock. Consequently, a food-entrained oscillator has been proposed to be responsible for meal time estimation. Recent studies suggested the dorsomedial hypothalamus (DMH) as the site for this food-entrained oscillator, which has led to considerable controversy in the literature. Herein we demonstrate by means of c-Fos immunohistochemistry that the neuronal activity of the suprachiasmatic nucleus (SCN), which signals the rest phase in nocturnal animals, is reduced when animals anticipate the scheduled food and, simultaneously, neuronal activity within the DMH increases. Using retrograde tracing and confocal analysis, we show that inhibition of SCN neuronal activity is the consequence of activation of GABA-containing neurons in the DMH that project to the SCN. Next, we show that DMH lesions result in a loss or diminution of FAA, simultaneous with increased activity in the SCN. A subsequent lesion of the SCN restored FAA. We conclude that in intact animals, FAA may only occur when the DMH inhibits the activity of the SCN, thus permitting locomotor activity. As a result, FAA originates from a neuronal network comprising an interaction between the DMH and SCN. Moreover, this study shows that the DMH–SCN interaction may serve as an intrahypothalamic system to gate activity instead of rest overriding circadian predetermined temporal patterns.
Voltage-gated potassium channel
KCNV2
(Kv8.2) contributes to epilepsy susceptibility
Authors: Jorge Benjamin S. , Campbell Courtney M. , Miller Alison R. , Rutter Elizabeth D. , Gurnett Christina A. , Vanoye Carlos G. , George Alfred L. , Kearney Jennifer A.
Published: March 2011

Mutations in voltage-gated ion channels are responsible for several types of epilepsy. Genetic epilepsies often exhibit variable severity in individuals with the same mutation, which may be due to variation in genetic modifiers. The

Scn2a
Q54

transgenic mouse model has a sodium channel mutation and exhibits epilepsy with strain-dependent severity. We previously mapped modifier loci that influence

Scn2a
Q54

phenotype severity and identified
Kcnv2
, encoding the voltage-gated potassium channel subunit Kv8.2, as a candidate modifier. In this study, we demonstrate a threefold increase in hippocampal
Kcnv2
expression associated with more severe epilepsy. In vivo exacerbation of the phenotype by
Kcnv2
transgenes supports its identification as an epilepsy modifier. The contribution of
KCNV2
to human epilepsy susceptibility is supported by identification of two nonsynonymous variants in epilepsy patients that alter function of Kv2.1/Kv8.2 heterotetrameric potassium channels. Our results demonstrate that altered potassium subunit function influences epilepsy susceptibility and implicate
Kcnv2
as an epilepsy gene.
Synchronicity, instant messaging, and performance among financial traders
Authors: Saavedra Serguei , Hagerty Kathleen , Uzzi Brian
Published: March 2011

Successful animal systems often manage risk through synchronous behavior that spontaneously arises without leadership. In critical human systems facing risk, such as financial markets or military operations, our understanding of the benefits associated with synchronicity is nascent but promising. Building on previous work illuminating commonalities between ecological and human systems, we compare the activity patterns of individual financial traders with the simultaneous activity of other traders—an individual and spontaneous characteristic we call synchronous trading. Additionally, we examine the association of synchronous trading with individual performance and communication patterns. Analyzing empirical data on day traders’ second-to-second trading and instant messaging, we find that the higher the traders’ synchronous trading is, the less likely they are to lose money at the end of the day. We also find that the daily instant messaging patterns of traders are closely associated with their level of synchronous trading. This result suggests that synchronicity and vanguard technology may help traders cope with risky decisions in complex systems and may furnish unique prospects for achieving collective and individual goals.
Iron enzyme ribulose-5-phosphate 3-epimerase in
Escherichia coli
is rapidly damaged by hydrogen peroxide but can be protected by manganese
Authors: Sobota Jason M. , Imlay James A.
Published: March 2011

H
2
O
2
is commonly generated in biological habitats by environmental chemistry and by cellular immune responses. H
2
O
2
penetrates cells, disrupts metabolism, and blocks growth; it therefore is of interest to identify the major cellular molecules that H
2
O
2
damages and the strategies by which cells protect themselves from it. We used a strain of
Escherichia coli
that lacks catalases and peroxidases to impose protracted low-grade H
2
O
2
stress. Physiological analysis indicated that the pentose–phosphate pathway, in particular, was poisoned by submicromolar intracellular H
2
O
2
. Assays determined that ribulose-5-phosphate 3-epimerase (Rpe) was specifically inactivated. In vitro studies demonstrated that Rpe employs a ferrous iron atom as a solvent-exposed cofactor and that H
2
O
2
rapidly oxidizes this metal in a Fenton reaction. The oxidized iron is released immediately, causing a loss of activity. Most Rpe proteins could be reactivated by remetallation; however, a small fraction of proteins were irreversibly damaged by each oxidation cycle, and so repeated cycles of oxidation and remetallation progressively led to permanent inactivation of the entire Rpe pool. Manganese import and iron sequestration are key elements of the H
2
O
2
stress response, and we found that manganese can activate Rpe in vitro in place of iron, converting the enzyme to a form that is unaffected by H
2
O
2
. Indeed, the provision of manganese to H
2
O
2
–stressed cells protected Rpe and enabled the pentose–phosphate pathway to retain function. These data indicate that mononuclear iron enzymes can be primary targets of H
2
O
2
stress and that cells adapt by shifting from iron- to manganese-centered metabolism.