bluuebunny/crossref_metadata_2025 huggingface dataset:
Searching for a sense of purpose: The role of parents and effects on self‐esteem among female adolescents
Authors: Blattner Meghan C.C. , Liang Belle , Lund Terese , Spencer Renee
Published: July 2013

Achieving a sense of purpose during adolescence is a developmental asset; however, searching for that purpose may be a developmental stressor. Supportive parent–child relationships may help youth during this stressful experience. The present study included 207 female students in the sixth, eighth, and tenth grades from two competitive private schools. Searching for purpose negatively predicted self‐esteem. Hierarchical linear regression examined moderating effects of parental trust and alienation on searching for purpose as a predictor of self‐esteem. Parental alienation significantly moderated the association between search for purpose and girls' self‐esteem; conversely, parental trust did not moderate the association. Results suggest that parent–child relationships characterized by high levels of parental alienation may exacerbate the pernicious effects of search for purpose. Person‐based analyses found four clusters corresponding to Foreclosed Purpose, Diffused Purpose, Uncommitted Purpose/Moratorium, and Achieved Purpose. We discuss implications for practice and research based on these results.
Recurrence of a Periosteal Ganglion in the Tibia
Authors: Samuel Ling Ka-Kin , Hon-Wah Yiu , Tun-Hing Lui , Wai-Kit Ngai
Published: July 2013

Periosteal ganglion is a rare type of ganglia most commonly located in the tibia. The clinical outcomes after surgical excision have not been documented in literature. We report a case of a periosteal ganglion in the proximal tibia with repeated recurrences despite surgical excisions. Magnetic resonance imaging (MRI), contrast arthrogram, and arthroscopy may have their values, especially for the detection of intra-articular communication in juxta-articular lesions.
Multiphase flow in porous media
Authors: Higdon J. J. L.
Published: July 2013

Multiphase flows in porous media represent fluid dynamics problems of great complexity involving a wide range of physical phenomena. These flows have attracted the attention of an impressive group of renowned researchers and have spawned a number of classic problems in fluid dynamics. These multiphase flows are perhaps best known for their importance in oil recovery from petroleum reservoirs, but they also find application in novel areas such as hydrofracturing for natural gas recovery. In a recent article, Zinchenko & Davis (J. Fluid Mech. 2013, vol. 725, pp. 611–663) present computational simulations that break new ground in the study of emulsions flowing through porous media. These simulations provide sufficient scale to capture the disordered motion and complex break-up patterns of individual droplets while providing sufficient statistical samples for estimating meaningful macroscopic properties of technical interest.
ART AND POLITICAL DISSENT IN POSTWAR LEBANON: WALID SADEK'SFI ANNANI AKBAR MIN BIKASU[BIGGER THAN PICASSO]
Authors: Mejcher-Atassi Sonja
Published: July 2013

Taking Walid Sadek'sfi annani akbar min bikasu[bigger than picasso] as its starting point, this article examines relations of art and politics in post-civil war Lebanon. A tiny and inexpensive paperback related to Picasso unfolds into a work of art that raises questions about the place of art and political dissent. After situatingbigger than picassoin the context of contemporary book art and artistic practices of the postwar generation in Lebanon, the article focuses on the juxtaposition of text and image. By placing narratives of art vandalism next to the image of a monument dedicated to the late Syrian President Hafiz al-Asad,bigger than picassoplayfully and provocatively breaks with political taboos at a time when the silence about the Lebanese Civil War (1975–90) and about Lebanese-Syrian relations was met with increasing anxiety. At the same time, the work makes room for aesthetic inquiries, exploring new possibilities of art at the margins of cultural production. The article concludes thatbigger than picassobrings to the fore the discrepancy between public monumentality and artistic practices, which in finding ways around political violence and censorship have recourse to ephemeral and private spheres, and holds unexpected meanings in ever-changing political circumstances.
Introduction
Authors: Çelik Zeynep
Published: July 2013

The study of the visual culture of the Middle East covers a wealth of topics from the birth of Islam to the present day and has long been marked by rigorous theoretical and methodological inquiries. Nevertheless, it has remained largely at the margins of Middle East studies, as measured by the limited space it occupies in interdisciplinary publications and conferences. This may perhaps be explained by a misconception that its reliance on “pictures” makes it a lighter, albeit pleasurable, complement to the more “serious” disciplines. Yet, due in part to the blurring of disciplinary boundaries and in part to the new wave of technological innovations, visual references now appear more frequently in the work of social and political historians, anthropologists, and even political scientists. In the process, some methodological tools for using visual material as primary documents risk being lost, as images are relegated to “decorative” backgrounds.
Lost Histories of a Licit Figural Art
Authors: Flood Finbarr Barry
Published: July 2013

The idea that theology is either irrelevant to artistic production or “a baleful influence” on its history has recently been critically explored by Jeffrey Hamburger, in relation to medieval Christian art. Engaging the perennial problem of moving between immaterial concepts, normative texts, and material things, Hamburger's observations resonate with the long shadow cast by theBilderverbot, the prohibition of images often assumed to characterize Islamic and Jewish cultures, on the modern reception of Islamic art.
Management of prolonged epistaxis in pregnancy: case report
Authors: Cornthwaite K , Varadharajan K , Oyarzabal M , Watson H
Published: July 2013

Objectives:

To report a case of life-threatening epistaxis in a pregnant patient, describe the links between pregnancy and epistaxis, and discuss the management of such cases. Life-threatening epistaxis in pregnancy is rare, and there are no specific evidence-based guidelines regarding the management of these patients.

Case report:

A 31-year-old primigravida presented with severe epistaxis in the second trimester of her pregnancy. Conservative measures failed, thereby necessitating surgical intervention.

Conclusion:

This case illustrates the importance of a multidisciplinary approach in the management of a pregnant patient presenting with severe epistaxis, and highlights the surgical challenges presented in such a situation.
Soliton dynamics in an extended nonlinear Schrödinger equation with a spatial counterpart of the stimulated Raman scattering
Authors: GROMOV E. M. , MALOMED B. A.
Published: July 2013

The dynamics of solitons is considered in the framework of the extended nonlinear Schrödinger equation (NLSE), which is derived from a system of Zakharov's type for the interaction between high-frequency (HF) and low-frequency (LF) waves, in which the LF field is subject to diffusive damping. The model may apply to the propagation of HF waves in plasmas. The resulting NLSE includes a pseudo-stimulated-Raman-scattering (PSRS) term, i.e. a spatial-domain counterpart of the SRS term, which is well known as an ingredient of the temporal-domain NLSE in optics. Also included is inhomogeneity of the spatial second-order diffraction (SOD). It is shown that the wavenumber downshift of solitons, caused by the PSRS, may be compensated by an upshift provided by the SOD whose coefficient is a linear function of the coordinate. An analytical solution for solitons is obtained in an approximate form. Analytical and numerical results agree well, including the predicted balance between the PSRS and the linearly inhomogeneous SOD.
Ion acoustic waves in expanding strongly coupled plasmas
Authors: MENDONÇA J. T. , SHUKLA N. , RESENDES D. P. , SERBETO A.
Published: July 2013

We consider the excitation and dispersion of ion acoustic waves in expanding ultracold plasmas, taking into account the influence of boundary conditions. A cylindrical plasma geometry is assumed. We show that temporal changes in the medium lead to a wave frequency shift, associated with an evolving radial and standing wave mode structure, and to the temporal change of the background plasma parameters. A non-collisional model for the cylindrical geometry is also proposed.
Resistance, Engagement, and Heritage Conservation by Voluntary Sector: The Case of Penang in Malaysia
Authors: CHENG EDMUND W. , LI ANTHONY H. F. , MA SHU-YUN
Published: July 2013

An enduring question with regard to the voluntary sector is how it can nurture civic engagement and provide public goods. A World Heritage listing for Penang highlights this question by revealing a vibrant civil society network that has made heritage conservation an issue for public discourse and policy agenda. This paper discusses how the marginalized trajectory of Penang is related to the development of its civic realm, social cohesion and local identity, which are sources of Penang's voluntarism. It then examines the engagement pattern of the Penang Heritage Trust, a leading association, which has mounted resistance against the state's failure in heritage provision. This bottom-up approach has preserved Penang's cultural heritage and associated identity, and reveals the distinct nature and capacity of Penang's voluntary sector that goes against the general pattern in Malaysia.
Sarcosporidiosis in Ducks
Authors: Riley William A.
Published: July 2013

That ducks are subject to infestation by sarcosporidia has long been known. It seems to have been emphasised particularly because ducks afforded one of the first-known instances of the occurrence of these puzzling protozoa in birds. Very few new records have been published until now and no adequate illustrations of the gross features of the infestation have appeared. A general review of the subject and presentation of additional cases, with illustrations, therefore seems desirable.
Do Penetrating Nematode Larvae assist Bacterial Invasion from the Bowel?
Authors: Taylor E. Leonard , Purchase Harvey S.
Published: July 2013

That parasitic worms may induce bacterial invasion from the intestine has frequently been asserted in explanation of the sporadic occurrence of some bacterial and virus diseases of animals. Weinberg, in 1907, gave an extensive review of the literature dealing with inflammatory conditions of the intestine, due to bacterial invasion associated with parasitic worms. He also gave an account of some original clinical observations. He concluded that, by biting and boring into the intestinal wall, or by wounding it with hooks and suckers, the majority of helminths favour the penetration of microbes, these being carried on the exterior and in the intestine of the worms. In one case, where a fatal septicaemia was associated with the presence of a single individual Trichocephalus, the author's conclusion, that even isolated worms are very dangerous, appears to be rather strained. Records of clinical observations of this kind frequently appear in the literature, but, as a general rule, the evidence showing the agency of the worm is very slender and amounts to little more than the observation of the presence of worms in animals suffering from some bacterial disease.
Indigenous Knowledge and Contact Zones: The Case of the Cold Bokkeveld Meteorite, Cape Colony, 1838
Authors: Musselman Elizabeth Green
Published: July 2013

Historians of science and technology—with much assistance from the work of world historians, environmental historians, anthropologists, and archaeologists—have begun to develop some promising scholarly apparatus for decentring European science in world history. But we are still a long way away from developing a comprehensive, accessible frame in which European science is simply one (albeit very successful) way of conceptualising the natural world.
Encountering the Netherlands Indies: Caspar G.C. Reinwardt's Field Trip to the East (1816–1822)
Authors: Weber Andreas
Published: July 2013

In the years after its foundation in 1814, the United Kingdom of the Netherlands witnessed the emergence of several new sites where natural history—the study of naming, describing and classifying plants, animals and minerals—was carried out. These new sites, such as the Rijksmuseum van Natuurlijke Historie (National Museum for Natural History), founded in 1820, the Rijksherbarium (National Herbarium) and the colonial site Nederlands-Indië (Netherlands Indies) had not existed in that form and in that combination before. The Rijksmuseum and the Rijksherbarium, established in Brussels in 1829, were the first national and fully state-funded natural historical institutions in the Dutch kingdom. In the course of the nineteenth century, both institutions rapidly developed into well-known centres for natural historical research in Europe. Significant parts of their collections derived from the Malay Archipelago, a region the Dutch kingdom regained from the British for strategic reasons in 1814. In the first half of the nineteenth century, the Malay Archipelago, which had remained a terra incognita to European naturalists and colonial administrators, witnessed an unprecedented run on its natural wealth—initiated and propelled by both the emerging Dutch colonial state and the natural historical institutions in the Netherlands.
Denmark-Norway as a Potential World Power in the Early Seventeenth Century
Authors: Jónsson Már
Published: July 2013

On 2 January 1625, the English ambassador Robert Anstruther met with King Christian IV of Norway and Denmark and requested his participation in a union of Protestant states against Emperor Ferdinand II and the Catholic League in Germany. Within three days, King Christian proposed to contribute five thousand soldiers for one year, as part of an army of almost thirty thousand men. In early June, despite opposition from the Danish Council of State, reluctant to put a huge amount of money into foreign affairs, Christian decided to join what he called “the war for the defence of Lower Saxony”. He then headed an army of mercenaries southwards through Lower Saxony, secured all crossings over the river Weser and prepared to confront the Catholic forces. On 29 November, it was decided that Denmark would be in charge of military operations in Northern Germany, whereas England and the United Provinces would provide a monthly subsidy. The political and military prospects for Denmark were excellent, to say the least. It had the fourth strongest navy in Europe (after Spain and the two new allies), and only a few years before the Danish warships had been described by a French observer as “merveilles de l'océan”. A small standing army of two regiments had recently been established and Denmark was the fourth European state to do so after France, Spain and the neighbouring Sweden.
A Balancing Act: The Norwegian Lutheran Mission in French Colonial Madagascar
Authors: Skeie Karina Hestad
Published: July 2013

The plural and particularised expressions of colonialism remain a central concern for post-colonial studies. This paper will discuss the role of the Norwegian Lutheran mission in colonial Madagascar in the late-nineteenth and early-twentieth centuries. The case of a Protestant mission from a small European country operating in a French colony provides an interesting opportunity to explore the implications of inter-European dynamics in colonial politics and the role of religion in the relationships between missionaries, colonial subjects, and colonial powers.
Diagrams in biology
Authors: Perini Laura
Published: July 2013

Biologists depend on visual representations, and their use of diagrams has drawn the attention of philosophers, historians, and sociologists interested in understanding how these images are involved in biological reasoning. These studies, however, proceed from identification of diagrams on the basis of their spare visual appearance, and do not draw on a foundational theory of the nature of diagrams as representations. This approach has limited the extent to which we understand how these diagrams are involved in biological reasoning. In this paper, I characterize three different kinds of figures among those previously identified as diagrams. The features that make these figures distinctive as representational types, furthermore, illuminate the ways in which they are involved in biological reasoning.
Unsupervised acquisition of entailment relations from the Web
Authors: SZPEKTOR IDAN , TANEV HRISTO , DAGAN IDO , COPPOLA BONAVENTURA , KOUYLEKOV MILEN
Published: July 2013

Entailment recognition is a primary generic task in natural language inference, whose focus is to detect whether the meaning of one expression can be inferred from the meaning of the other. Accordingly, many NLP applications would benefit from high coverage knowledgebases of paraphrases and entailment rules. To this end, learning such knowledgebases from the Web is especially appealing due to its huge size as well as its highly heterogeneous content, allowing for a more scalable rule extraction of various domains. However, the scalability of state-of-the-art entailment rule acquisition approaches from the Web is still limited. We present a fully unsupervised learning algorithm for Web-based extraction of entailment relations. We focus on increased scalability and generality with respect to prior work, with the potential of a large-scale Web-based knowledgebase. Our algorithm takes as its input a lexical–syntactic template and searches the Web for syntactic templates that participate in an entailment relation with the input template. Experiments show promising results, achieving performance similar to a state-of-the-art unsupervised algorithm, operating over an offline corpus, but with the benefit of learning rules for different domains with no additional effort.
Manage Your Life Online (MYLO): A Pilot Trial of a Conversational Computer-Based Intervention for Problem Solving in a Student Sample
Authors: Gaffney Hannah , Mansell Warren , Edwards Rachel , Wright Jason
Published: July 2013

Background: Computerized self-help that has an interactive, conversational format holds several advantages, such as flexibility across presenting problems and ease of use. We designed a new program called MYLO that utilizes the principles of Method of Levels (MOL) therapy - based upon Perceptual Control Theory (PCT). Aims: We tested the efficacy of MYLO, tested whether the psychological change mechanisms described by PCT mediated its efficacy, and evaluated effects of client expectancy. Method: Forty-eight student participants were randomly assigned to MYLO or a comparison program ELIZA. Participants discussed a problem they were currently experiencing with their assigned program and completed measures of distress, resolution and expectancy preintervention, postintervention and at 2-week follow-up. Results: MYLO and ELIZA were associated with reductions in distress, depression, anxiety and stress. MYLO was considered more helpful and led to greater problem resolution. The psychological change processes predicted higher ratings of MYLO's helpfulness and reductions in distress. Positive expectancies towards computer-based problem solving correlated with MYLO's perceived helpfulness and greater problem resolution, and this was partly mediated by the psychological change processes identified. Conclusions: The findings provide provisional support for the acceptability of the MYLO program in a non-clinical sample although its efficacy as an innovative computer-based aid to problem solving remains unclear. Nevertheless, the findings provide tentative early support for the mechanisms of psychological change identified within PCT and highlight the importance of client expectations on predicting engagement in computer-based self-help.
THE CASH-IN-ADVANCE CONSTRAINT IN MONETARY GROWTH MODELS WITH LABOR MARKET SEARCH
Authors: Heer Burkhard , Maußner Alfred
Published: July 2013

We study the sensitivity of the inflation–growth trade-off in monetary growth models to the introduction of search frictions in the labor market. We consider three types of endogenous growth models: (1) the AK model, (2) the Lucas supply-side model, and (3) the two-sector model of Jones and Manuelli. We show that the effects depend on the specification of the cash-in-advance constraint and the magnitude of the semi-interest elasticity of the income velocity. For the AK model, economic growth increases with higher inflation. For the other two models, growth declines for the case of the standard cash-in-advance constraint on consumption, whereas it either increases or decreases if money is introduced, as in the cash–credit good economy of Dotsey and Ireland, depending on the semi-interest elasticity of the income velocity. The welfare effects of inflation are shown to be economically significant in the presence of search unemployment.
“Watch Out For The Sharks”: Gender, Technology, and Commerce in the American Song-Poem Industry
Authors: INGLESE FRANCESCA
Published: July 2013

Since the early 1900s, song-poem entrepreneurs, often referred to as “song sharks,” have fueled a diffuse and largely hidden American industry that produces music to accompany the poems and lyrics of amateur writers. These entrepreneurs have long been demonized in the popular media for preying on the naiveté of their clientele. Yet despite charges of exploitation, this musical equivalent of the vanity press has survived for over a century. Although the vast majority of song-poets and their song-poems have remained in obscurity, in the 1990s, song-poems developed a cult following among record collectors; as “anonymous collaborations,” these recordings highlighted tensions between poignant personal expression and impersonal commercial rendering that appealed to listeners with a penchant for the obscure. This article draws on advertisements, sheet music, media coverage, and personal interviews to piece together a history of the song-poem industry, with particular focus on the gendered dimensions of the practice, the role of technology in the production process, and the multiplicity of meanings embedded in song-poems for both song-poets and collectors.
Enhancing Majority Members’ Pro-Diversity Beliefs in Small Teams
Authors: van Veelen Ruth , Otten Sabine , Hansen Nina
Published: July 2013

Majority members often react negatively to efforts to stimulate diversity. An important reason for this is that in diverse groups, majority members’ own group bond is typically based on perceived prototypicality, which serves to disregard those who are different. In the present research we investigate how majority members’ pro-diversity beliefs may be enhanced, by experimentally manipulating how the self is cognitively defined in relation to a diverse group. Specifically, we hypothesize that majority members’ focus on the personal self (i.e., self-anchoring) rather than the social self (i.e., self-stereotyping) when creating a group bond may facilitate their pro-diversity beliefs and positive attitudes toward minority members. In two experiments we manipulated self-anchoring and self-stereotyping via mindset priming among ethnic majority members in diverse teams. As expected, results showed that relative to self-stereotyping, majority members’ self-anchoring enhanced pro-diversity beliefs and positive attitudes toward minority members.
Factoring and testing primes in small space
Authors: Geffert Viliam , Pardubská Dana
Published: July 2013

We discuss how much space is sufficient to decide whether a unary given number
n is a prime. We show that
O(log log n) space is sufficient for a deterministic
Turing machine, if it is equipped with an additional pebble movable along the input tape,
and also for an alternating machine, if the space restriction applies only to its
accepting computation subtrees. In other words, the language is a prime is in
pebble–DSPACE(log log n) and also in
accept–ASPACE(log log n). Moreover, if the given
n is composite, such machines are able to find a divisor of
n. Since O(log log n) space is too
small to write down a divisor, which might require
Ω(log n) bits, the witness divisor is indicated by the
input head position at the moment when the machine halts.
Photoacoustic tomography using a Michelson interferometer with quadrature phase detection
Authors: Speirs Rory W. , Bishop Alexis I.
Published: July 2013

We present a pressure sensor based on a Michelson interferometer, for use in photoacoustic tomography. Quadrature phase detection is employed allowing measurement at any point on the mirror surface without having to retune the interferometer, as is typically required by Fabry-Perot type detectors. This opens the door to rapid full surface detection, which is necessary for clinical applications. Theory relating acoustic pressure to detected acoustic particle displacements is used to calculate the detector sensitivity, which is validated with measurement. Proof-of-concept tomographic images of blood vessel phantoms have been taken with sub-millimeter resolution at depths of several millimeters.
A comparison between state-specific and linear-response formalisms for the calculation of vertical electronic transition energy in solution with the CCSD-PCM method
Authors: Caricato Marco
Published: July 2013

The calculation of vertical electronic transition energies of molecular systems in solution with accurate quantum mechanical methods requires the use of approximate and yet reliable models to describe the effect of the solvent on the electronic structure of the solute. The polarizable continuum model (PCM) of solvation represents a computationally efficient way to describe this effect, especially when combined with coupled cluster (CC) methods. Two formalisms are available to compute transition energies within the PCM framework: State-Specific (SS) and Linear-Response (LR). The former provides a more complete account of the solute-solvent polarization in the excited states, while the latter is computationally very efficient (i.e., comparable to gas phase) and transition properties are well defined. In this work, I review the theory for the two formalisms within CC theory with a focus on their computational requirements, and present the first implementation of the LR-PCM formalism with the coupled cluster singles and doubles method (CCSD). Transition energies computed with LR- and SS-CCSD-PCM are presented, as well as a comparison between solvation models in the LR approach. The numerical results show that the two formalisms provide different absolute values of transition energy, but similar relative solvatochromic shifts (from nonpolar to polar solvents). The LR formalism may then be used to explore the solvent effect on multiple states and evaluate transition probabilities, while the SS formalism may be used to refine the description of specific states and for the exploration of excited state potential energy surfaces of solvated systems.
Thermal analysis of a solar distillation system for ethanol-water solutions
Authors: Pablo Vargas-B. J. , Pérez-García Santiago L. , García-Cuéllar Alejandro J. , Rivera-Solorio Carlos I.
Published: July 2013

The dimensions, volumetric flow rates, and thermal capacities of an ethanol distillation system where solar energy is used as primary energy are examined in this article. A rigorous thermodynamic equilibrium analysis is applied to obtain the critical design parameters for the solar distillation of an ethanol-water solution with different feed stream concentrations (5%, 7%, and 10% wt. ethanol) to obtain a distillate product of 95% wt. ethanol. The volumetric flow of the feed stream is varied and a sensitivity analysis is performed to study its impact on the design of the solar distillation system. Important technical details, such as the configuration of the solar distillation system, the size of the distillation columns, reboiler heat duty, energy consumption per unit mass of distillate product, solar fraction, and collector area, among others, are evaluated and presented as a guideline for designers. The methodology developed herein is used to design the solar ethanol distillation system and can be extended to other geographical locations, weather conditions, and operational parameters.
The influence of trehalose on hydrophobic interactions of small nonpolar solute: A molecular dynamics simulation study
Authors: Paul Subrata , Paul Sandip
Published: July 2013

Molecular dynamics simulations were carried out to investigate the influences of aqueous trehalose solution on the hydrophobic interactions between neopentane molecules. In this study, we consider six different trehalose concentrations ranging from 0% to 56%. We observe that with increasing trehalose concentration the dispersion of solute neopentane takes place. The neopentane-neopentane association constant value decreases with addition of trehalose. Our preferential interaction calculations suggest that with increasing trehalose concentration neopentane interacts preferentially with water over trehalose. Site-site neopentane-trehalose rdfs indicate that trehalose molecules are expelled out from the neopentane surface. Also observed are (i) trehalose induced second shell collapse of water network (ii) decrease in average number of water-water and water-trehalose hydrogen bonds with increasing trehalose concentration. We also find that addition of trehalose decreases the translational motion of all the solution species. The decrease in diffusion coefficient value is more pronounced for trehalose. We, further, observe that the ratio of the diffusion coefficient values of water and trehalose increases with increasing trehalose concentration.
Influence of neighboring reactive particles on diffusion-limited reactions
Authors: Eun Changsun , Kekenes-Huskey Peter M. , McCammon J. Andrew
Published: July 2013

Competition between reactive species is commonplace in typical chemical reactions. Specifically the primary reaction between a substrate and its target enzyme may be altered when interactions with secondary species in the system are substantial. We explore this competition phenomenon for diffusion-limited reactions in the presence of neighboring particles through numerical solution of the diffusion equation. As a general model for globular proteins and small molecules, we consider spherical representations of the reactants and neighboring particles; these neighbors vary in local density, size, distribution, and relative distance from the primary target reaction, as well as their surface reactivity. Modulations of these model variables permit inquiry into the influence of excluded volume and competition on the primary reaction due to the presence of neighboring particles. We find that the surface reactivity effect is long-ranged and a strong determinant of reaction kinetics, whereas the excluded volume effect is relatively short-ranged and less influential in comparison. As a consequence, the effect of the excluded volume is only modestly dependent on the neighbor distribution and is approximately additive; this additivity permits a linear approximation to the many-body effect on the reaction kinetics. In contrast, the surface reactivity effect is non-additive, and thus it may require higher-order approximations to describe the reaction kinetics. Our model study has broad implications in the general understanding of competition and local crowding on diffusion-limited chemical reactions.
An environmental sample chamber for reliable scanning transmission x-ray microscopy measurements under water vapor
Authors: Kelly Stephen T. , Nigge Pascal , Prakash Shruti , Laskin Alexander , Wang Bingbing , Tyliszczak Tolek , Leone Stephen R. , Gilles Mary K.
Published: July 2013

We have designed, fabricated, and tested a compact gas-phase reactor for performing in situ soft x-ray scanning transmission x-ray microscopy (STXM) measurements. The reactor mounts directly to the existing sample holder used in the majority of STXM instruments around the world and installs with minimal instrument reconfiguration. The reactor accommodates many gas atmospheres, but was designed specifically to address the needs of measurements under water vapor. An on-board sensor measures the relative humidity and temperature inside the reactor, minimizing uncertainties associated with measuring these quantities outside the instrument. The reactor reduces x-ray absorption from the process gas by over 85% compared to analogous experiments with the entire STXM instrument filled with process gas. Reduced absorption by the process gas allows data collection at full instrumental resolution, minimizes radiation dose to the sample, and results in much more stable imaging conditions. The reactor is in use at the STXM instruments at beamlines 11.0.2 and 5.3.2.2 at the Advanced Light Source.
Kinetics of ion and prompt electron emission from laser-produced plasma
Authors: Farid N. , Harilal S. S. , Ding H. , Hassanein A.
Published: July 2013

We investigated ion emission dynamics of laser-produced plasma from several elements, comprised of metals and non-metals (C, Al, Si, Cu, Mo, Ta, W), under vacuum conditions using a Faraday cup. The estimated ion flux for various targets studied showed a decreasing tendency with increasing atomic mass. For metals, the ion flux is found to be a function of sublimation energy. A comparison of temporal ion profiles of various materials showed only high-Z elements exhibited multiple structures in the ion time of flight profile indicated by the observation of higher peak kinetic energies, which were absent for low-Z element targets. The slower ions were seen regardless of the atomic number of target material propagated with a kinetic energy of 1–5 keV, while the fast ions observed in high-Z materials possessed significantly higher energies. A systematic study of plasma properties employing fast photography, time, and space resolved optical emission spectroscopy, and electron analysis showed that there existed different mechanisms for generating ions in laser ablation plumes. The origin of high kinetic energy ions is related to prompt electron emission from high-Z targets.
Strain mapping of Si devices with stress memorization processing
Authors: Wang Y. Y. , Bruley J. , van Meer H. , Li J. , Domenicucci A. , Murray C. E. , Rouviere J.
Published: July 2013

Dual lens dark field electron holography and Moiré fringe mapping from dark field scanning transmission electron microscopy are used to map strain distributions at high spatial resolution in Si devices processed with stress memorization techniques (SMT). It provides experimental evidence that strain in the Si channel is generated by dislocations resulting from SMT. The highest value of strain, up to 1.1% (1.9 GPa in stress) occurs at the Si surface along the channel direction: ⟨110⟩. An increase of ∼0.2% strain in the channel is observed after removing the poly-Si gate through the replacement high-k metal gate process.
Tunable anisotropic magnetoelectric effect in helimagnetic tunnel junctions with interface Rashba spin-orbit interaction
Authors: Wang Yan , Zhang Ning , Berakdar Jamal , Jia Chenglong
Published: July 2013

We investigate theoretically the influence of the Rashba spin-orbit interaction at the helical-multiferroic/ferromagnetic-oxide interface on the tunnel magnetotransport across multiferroic heterojunctions (e.g., Pt/TbMnO3/SrRuO3). In addition to a residual topological effective spin-orbit coupling induced by the spiral spin ordering in the helimagnetic barrier, the spin-dependent interaction results in an oscillatory tunneling anisotropic magnetoresistance (TAMR) with C2v symmetry. A large modulation of TAMR is realized by an external electric field due to the gate-controllable Rashba spin-orbit interaction and the magnetoelectric coupling, an effect of a potential for applications.
Negative refraction in one- and two-dimensional lossless plasma dielectric photonic crystals
Authors: Guo B.
Published: July 2013

Negative refraction in one- and two-dimensional lossless plasma dielectric photonic crystals consisting of plasma and background materials is theoretically investigated and the necessary conditions for negative refraction in these two structures are obtained. The critical frequency ω0 and the bandwidth Δω for negative refraction are explored, and the parameter dependence of effects such as plasma filling factor and the dielectric constant of background materials is also examined and discussed.
High color purity ZnSe/ZnS core/shell quantum dot based blue light emitting diodes with an inverted device structure
Authors: Ji Wenyu , Jing Pengtao , Xu Wei , Yuan Xi , Wang Yunjun , Zhao Jialong , Jen Alex K.-Y.
Published: July 2013

Deep-blue, high color purity electroluminescence (EL) is demonstrated in an inverted light-emitting device using nontoxic ZnSe/ZnS core/shell quantum dots (QDs) as the emitter. The device exhibits moderate turn-on voltage (4.0 V) and color-saturated deep blue emission with a narrow full width at half maximum of ∼15 nm and emission peak at 441 nm. Their maximum luminance and current efficiency reach 1170 cd/m2 and 0.51 cd/A, respectively. The high performances are achieved through a ZnO nanoparticle based electron-transporting layer due to efficient electron injection into the ZnSe/ZnS QDs. Energy transfer processes between the ZnSe/ZnS QDs and hole-transporting materials are studied by time-resolved photoluminescence spectroscopy to understand the EL mechanism of the devices. These results provide a new guide for the fabrication of efficient deep-blue quantum dot light-emitting diodes and the realization of QD-based lighting sources and full-color panel displays.
Graphene-silver nanowire hybrid structure as a transparent and current spreading electrode in ultraviolet light emitting diodes
Authors: Hoon Seo Tae , Kyoung Kim Bo , Shin GangU , Lee Changhyup , Jong Kim Myung , Kim Hyunsoo , Suh Eun-Kyung
Published: July 2013

We report a device that combines graphene film and Ag nanowires (AgNWs) as transparent and current spreading electrodes for ultra-violet (UV) light emitting diode (LED) with interesting characteristics for the potential use in the deep UV region. The current-voltage characteristics and electroluminescence (EL) performance show that graphene network on AgNWs well-operates as a transparent and current spreading electrode in UV LED devices. In addition, scanning electron microscopy and EL images exhibit that graphene film act as the protection layer of AgNWs layer as well as a transparent conducting network, by bridging AgNWs.
High-performance n-type organic thin-film phototransistors based on a core-expanded naphthalene diimide
Authors: Qi Zhe , Liao Xiaxia , Zheng Jincheng , Di Chong-an , Gao Xike , Wang Jizheng
Published: July 2013

High-performance n-type organic phototransistors (OPTs) based on a core-expanded naphthalene diimide are reported in this letter. The photo responsivity is as high as 27000 AW−1 and photocurrent/dark-current ratio reaches 1.1 × 107 under a white light illumination with a power density of 107 μWcm−2. In such OPTs, persistent photoconductivity (PPC) is observed, which can be instantly eliminated by a positive gate voltage pulse. This is explained in terms of trapped photo holes in the channel. In the light on-off switching test, such PPC also leads to well-reproducible memory effect in the OPTs.
Bifunctional properties of hydrothermal synthesized BaMF4 (M = Co, Ni and Zn)
Authors: Sayed Farheen N. , Mandal B. P. , Jayakumar O. D. , Tyagi A. K.
Published: July 2013

BaMF4 (M = Co, Ni and Zn) samples having orthorhombic structure have been synthesized by a mild hydrothermal method and characterized by x-ray diffraction (XRD), magnetic and electrical measurements. Single phase formation of these compounds has been found to be dependent on various factors like reaction time, pH, temperature etc. All the samples showed ferroelectricity, which decreases with increase in temperature. BaMF4 (M = Co, Ni) samples show 10-15 times more leakage current compared to that of BaZnF4 at higher applied field. Absence of multivalent ions in BaZnF4 can be the reason for its minimum leakage current. All the samples except, BaZnF4, exhibit weak room temperature ferromagnetism also.
Nucleophilic Aromatic Substitution of Bis(pentafluorophenyl)mercury with Various Bulky Nucleophiles and the Structures of [Hg(C6F4X-4)2] (X=cyclo-C5H10N, OCH(CH3)2, OC(CH3)3)
Authors: Deacon Glen B. , Junk Peter C. , Luu Jenny
Published: July 2013

Reactions of bis(pentafluorophenyl)mercury with piperidine, sodium iso-propoxide or sodium tert-butoxide have yielded the corresponding 4-substituted tetrafluorophenylmercurials, [Hg(C6F4X-4)2] (X = cyclo-C5H10N (1), OCH(CH3)2 (2), OC(CH3)3 (3)), in reasonable yields but the bulkier nucleophiles, cis-2,6-dimethylpiperidine and 2,6-di-iso-propylphenolate (from sodium 2,6-di-iso-propylphenolate) decomposed the mercurial into pentafluorobenzene. Treatment of bis(pentafluorophenyl)mercury with another bulky nucleophile, 2,6-diphenylphenolate (from sodium 2,6-diphenylphenolate), in methanol, resulted in the unexpected formation of [Hg(C6F4(OMe)-4)2] (4). The structures of all the mercurials have linear C–Hg–C stereochemistry with two coplanar aryl rings. Amongst a complex series of supramolecular interactions, Hg⋯O bonding is observed for the alkoxy substituted mercurials but there are no Hg⋯N interactions in the structure of bis(2,3,5,6-tetrafluoro-4-piperidinophenyl)mercury.
The effects of temperature on larval size in the western king prawn, Penaeus (Melicertus) latisulcatus Kishinouye, from Spencer Gulf, South Australia: implications for fishery management
Authors: Rodgers G. G. , Roberts S. D. , Dixon C. D.
Published: July 2013

Temperature, salinity and food availability are generally considered to have the most influence on larval growth and survival in penaeid species. Larval size has previously been used as a measure of animal quality in a range of crustacean species. The aim of this project was to investigate the effects of temperature (17°C, 20°C, 22.5°C and 25°C) on stage-specific larval size in Penaeus latisulcatus collected from the Spencer Gulf, in South Australia. Five different measurements of larval size were assessed: body length, body width, antenna length, carapace length and abdomen length. Results showed that larval growth rate was dependant on temperature, with growth rate greater at higher temperatures. Despite this, larvae reared at 20°C reached the largest size, while those at the temperature extremes (17°C and 25°C) were smallest. When considering average annual temperature, the spawning time that would most likely maximise larval size in the Spencer Gulf is approximately December. This coincides with current management arrangements for the fishery that protect the spawning biomass at this time of year.
Phase-resetting mechanism of the circadian clock in
Chlamydomonas reinhardtii
Authors: Niwa Yoshimi , Matsuo Takuya , Onai Kiyoshi , Kato Daisaku , Tachikawa Makoto , Ishiura Masahiro
Published: July 2013

Although the circadian clock is a self-sustaining oscillator having a periodicity of nearly 1 d, its period length is not necessarily 24 h. Therefore, daily adjustment of the clock (i.e., resetting) is an essential mechanism for the circadian clock to adapt to daily environmental changes. One of the major cues for this resetting mechanism is light. In the unicellular green alga
Chlamydomonas reinhardtii
, the circadian clock is reset by blue/green and red light. However, the underlying molecular mechanisms remain largely unknown. In this study, using clock protein-luciferase fusion reporters, we found that the level of RHYTHM OF CHLOROPLAST 15 (ROC15), a clock component in
C. reinhardtii
, decreased rapidly after light exposure in a circadian-phase–independent manner. Blue, green, and red light were able to induce this process, with red light being the most effective among them. Expression analyses and inhibitor experiments suggested that this process was regulated mainly by a proteasome-dependent protein degradation pathway. In addition, we found that the other clock gene,
ROC114
, encoding an F-box protein, was involved in this process. Furthermore, we demonstrated that a
roc15
mutant showed defects in the phase-resetting of the circadian clock by light. Taken together, these data strongly suggest that the light-induced degradation of ROC15 protein is one of the triggers for resetting the circadian clock in
C. reinhardtii
. Our data provide not only a basis for understanding the molecular mechanisms of light-induced phase-resetting in
C. reinhardtii
, but also insights into the phase-resetting mechanisms of circadian clocks in plants.
Interferon-induced RIP1/RIP3-mediated necrosis requires PKR and is licensed by FADD and caspases
Authors: Thapa Roshan J. , Nogusa Shoko , Chen Peirong , Maki Jenny L. , Lerro Anthony , Andrake Mark , Rall Glenn F. , Degterev Alexei , Balachandran Siddharth
Published: July 2013

Significance

The interferons are small secreted proteins with powerful antiviral and cytotoxic properties. Here, we outline a signaling pathway activated by interferons that results in the precipitous necrotic death of susceptible cells. Interferon-induced necrosis proceeds via a novel, progressive mechanism that requires RNA transcription, as well as the sequential activity of three serine-threonine kinases: PKR, RIP1, and RIP3. This pronecrotic kinase cascade is normally held in check by FADD and caspases. As FADD can be disabled by phosphorylation during mitosis, our findings suggest the existence of a putative cell cycle-dependent checkpoint that licenses interferon-induced necrosis.
Insight into mechanisms of 3′-5′ exonuclease activity and removal of bulky 8,5′-cyclopurine adducts by apurinic/apyrimidinic endonucleases
Authors: Mazouzi Abdelghani , Vigouroux Armelle , Aikeshev Bulat , Brooks Philip J. , Saparbaev Murat K. , Morera Solange , Ishchenko Alexander A.
Published: July 2013

Significance

Oxidative DNA damage has been postulated to play an important role in human neurodegenerative disorders and cancer. 8,5′-cyclo-2′-deoxyadenosine (cdA) is generated in DNA by hydroxyl radical attack and strongly blocks DNA replication and transcription. Here we demonstrate that cdA adducts at 3′ termini of DNA can be removed by 3′-5′ exonuclease activity of the apurinic/apyrimidinic (AP) endonucleases:Escherichia coliXth and human APE1. The crystal structure of bacterial AP endonuclease in complex with DNA duplex provides insight into the mechanism of this activity. This new repair function provides an alternative pathway to counteract genotoxic effect of helix-distorting DNA lesions.
Open-atmosphere sustenance of highly volatile attoliter-size droplets on surfaces
Authors: Galliker Patrick , Schneider Julian , Rüthemann Lukas , Poulikakos Dimos
Published: July 2013

The controlled formation and handling of minute liquid volumes on surfaces is essential to the success of microfluidics in biology, chemistry, and materials applications. Even though current methods have demonstrated their potential in a variety of experimental assays, there remain significant difficulties concerning breadth of applicability, standardization, throughput, and economics. Here we introduce a unique microfluidic paradigm in which microscopic volatile droplets are formed, sustained, and manipulated in size and content at any desired spot on unpatterned substrates. Their sustainability is warranted by continuous replacement of the rapidly vaporizing sessile fluid through controlled equivalent volume deposition of smaller discrete liquid entities by an electrohydrodynamic nanodripping process. Using nanoparticle inks we show that the concentration of solutes in so-stabilized droplets can be linearly increased at isochoric conditions and user-defined rates. An intriguing insensitivity of the droplet shape toward surface heterogeneities ensures robustness and experimental reproducibility, even when handling attoliter quantities. The unique capabilities and technical simplicity of the presented method introduce a high degree of flexibility and make it pertinent to a diverse range of applications.