bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemistry and Geochronology of A-type Barabazar Granite: Implications on the Geodynamics of South Purulia Shear Zone, Singhbhum Craton, Eastern India
Authors: Dwivedi A. K. , Pandey U. K. , Murugan C. , Bhatt A. K. , Babu P. V. Ramesh , Joshi Mallikarjun
Published: June 2011

The Barabazar granite, exposed at the northern margin of Singhbhum craton, Eastern India, occurs along the South Purulia Shear Zone (SPSZ) and is emplaced into the Palaeoproterozoic metapelites and felsic volcanics of Singhbhum Group. Geochemical, petrographical and geochronological studies on the Barabazar granite addressed in the work have wide implications on understanding the geodynamics of SPSZ during Palaeoproterozoic to Mesoproterozoic. Geochemically, Barabazar granite displays limited range of major oxides, alkali enrichment and highly fractionated features (SiO2 > 75%; Eu/Eu* = 0.16-0.33; enrichment of K, Rb, Th, U and Nb; depletion of Ba, Sr, P and Ti). It is predominantly peraluminous (molar Al2O3/CaO+Na2O+K2O (A/CNK) =1.14-144) and contains abundant alkali feldspar, perthite, and minor plagioclase, biotite and accessory minerals. Geochemical and petrological data indicates that it is A-type granite, which formed in ‘Within plate granite’ tectonic set up. The Barabazar granite was emplaced at ca. 1771 Ma (Pb-Pb) in rift related environs and evolved by partial melting of stabilized lower/middle crust (initial 87Sr/86Sr = 0.7302 ± 0.0066 and μ1 = 8.5 ± 0.5). Subsequently, the shear zone (SPSZ) developed during the closure of the riftogenic basin and was reactivated during the Grenvillian orogeny (Ca. 900-1300 Ma), resulting in rehomogenisation of the strontium isotopes and thereby yielding younger whole-rock Rb-Sr isotope age of c. 971 Ma for the Barabazar granite. Probably during this tectonic event, the Singhbhum craton (Southern India Shield) would have finally juxtaposed with Northern Indian Shield along Central Indian Tectonic Zone (CITZ) during the global Grenvillian orogeny.
NELL‐1 binds to APR3 affecting human osteoblast proliferation and differentiation
Authors: Zou Xuan , Shen Jia , Chen Feng , Ting Kang , Zheng Zhong , Pang Shen , Zara Janette N. , Adams John S. , Soo Chia , Zhang Xinli
Published: June 2011

NELL1
physically interacts with
NOL10
by phage display (View interaction)
Corruption, Development and the Curse of Natural Resources
Authors: Pendergast Shannon M. , Clarke Judith A. , Van Kooten G. Cornelis
Published: June 2011

Abstract. Sachs and Warner (1995) found a negative relationship between natural resources and economic growth, concluding that natural resources are a curse. This explanation for poor economic growth is now widely accepted. We provide an alternative econometric framework for evaluating the resource curse. We focus on resource rents and rent-seeking behaviour, arguing that rent seeking affects corruption and that, in turn, impacts well-being. Our measure of well-being is the Human Development Index, although we find similar results for per capita GDP. While resource abundance does not directly impact economic development, we find that natural resources are associated with rent seeking that negatively affects well-being, with results robust to various model specifications and sensitivity analyses.

Résumé. Sachs et Warner (1995) ont observé une relation négative entre les ressources naturelles et la croissance économique et ils en ont conclu que les ressources naturelles étaient une malédiction. Cette explication de la faible croissance économique est maintenant largement acceptée. Nous offrons un cadre économétrique pour évaluer différemment cette malédiction des ressources. Nous nous concentrons sur les rentes tirées des ressources et sur la recherche de rente, en faisant valoir que la recherche de rente affecte la corruption, qui à son tour nuit au bien-être. Notre mesure du bien-être est l'indice de développement humain, même si nous trouvons des résultats similaires pour le PIB par habitant. Bien que l'abondance des ressources n'ait pas d'impact direct sur le développement économique, nous constatons que les ressources naturelles sont associées à la recherche de rente qui a une incidence négative sur le bien-être, comme en attestent nos résultats empiriques selon les diverses spécifications du modèle et des analyses de sensibilité.
ASSESSING WORLD ENGLISHES
Authors: Davies Alan
Published: June 2011

English worldwide may be viewed in terms of spread and of diffusion. Spread refers to the use in different global contexts, such as publishing and examinations, of Standard British or American English. Diffusion describes the emergence of local varieties of English in, for example, India or Singapore, comparable to the earlier emergence of Australian English, Canadian English, and so on. In nonformal settings, interlocutors make use of their own local variety of English, their World Englishes (WEs). In formal settings, notably in English language assessment, it seems that the norm appealed to is still that of Standard British or American English. Since English as a lingua franca (ELF) appears to make use only of the spoken medium, there is less of a demand for an ELF written norm. At present what seems to hold back the use of local WEs norms in formal assessment is less the hegemony of Western postcolonial and economic power and more the uncertainty of local stakeholders.
The Role of Cognition in School Refusal: An Investigation of Automatic Thoughts and Cognitive Errors
Authors: Maric Marija , Heyne David A. , de Heus Peter , van Widenfelt Brigit M. , Westenberg P. Michiel
Published: June 2011

Aims: The purpose of this study was to investigate the cognitions of anxious school refusers. The cognitive constructs under investigation included negative cognition commonly linked to youth anxiety (i.e. negative automatic thoughts and cognitive errors) and positive automatic thoughts. Method: The cognition of school refusers (n = 50) and youth from a community sample (n = 181) was assessed with the Children's Automatic Thoughts Scale-Negative/Positive and the Children's Negative Cognitive Error Questionnaire-Revised. Results: When controlling for anxiety, school refusers were found to report more negative automatic thoughts concerning personal failure, fewer negative automatic thoughts concerning hostility, and fewer positive automatic thoughts. Negative automatic thoughts concerning personal failure and hostility, and the negative cognitive error of overgeneralizing were found to independently predict school refusal. Conclusions: The findings underscore the importance of further researching the role of cognition in the development, maintenance, and treatment of anxiety-based school refusal.
Astronomical exploration and the public imagination
Authors: Blumberg Baruch S.
Published: June 2011

Humans have a need to understand where they fit in the cosmos. Driven by the unlimited possibilities of human imagination the night sky has been and is one of the most powerful stimulators of curiosity. In pre-modern times, farmers, pastoralists, travelers, even city dwellers unhampered by light pollution, had many opportunities to observe and wonder on the mysteries of the starry night. In this, the International Year of Astronomy marking the 400th anniversary of Galileo's telescopic observations (that is also the 200th anniversary of the birth of Charles Darwin) there are many explorations using the advanced and expensive instruments that society provides for satisfying the public curiosity and, of course, that of the astronomers trained to ask and answer the questions. However, it is a truism that scientific answers always raise new questions that could not have been asked raised prior to the preceding answers. The more we know the more we know about what we do not know; the task of scientific inquiry, or, for that matter, inquiry in general, is endless.
Starlight: a common heritage
Authors: Marin Cipriano
Published: June 2011

The Starlight Initiative brings a new view of the night sky and of its value enhancement, claiming the access to starlight as a scientific, environmental, and cultural right of humankind. Night sky quality has been seriously damaged in the last years because of light and atmospheric pollution, and an international action in favour of intelligent outdoor lighting is urgently needed. After the promulgation of the Starlight Declaration, we are jointly working with UNESCO, the World Heritage Centre, the MaB Programme, and other international institutions in the development of Starlight Reserves as exemplary areas that would act as models for the recovery of the heritage associated to star observation. The possibility arises to design and launch new tourist products and destinations based on astronomy and starry sceneries.
An astronomical observatory for Peru
Authors: del Mar Juan Quintanilla , Sicardy Bruno , Giraldo Víctor Ayma , Callo Víctor Raúl Aguilar
Published: June 2011

Peru and France are to conclude an agreement to provide Peru with an astronomical observatory equipped with a 60-cm diameter telescope. The principal aims of this project are to establish and develop research and teaching in astronomy. Since 2004, a team of researchers from Paris Observatory has been working with the University of Cusco (UNSAAC) on the educational, technical and financial aspects of implementing this venture. During an international astronomy conference in Cusco in July 2009, the foundation stone of the future Peruvian Observatory was laid at the top of Pachatusan Mountain. UNSAAC, represented by its Rector, together with the town of Oropesa and the Cusco regional authority, undertook to make the sum of 300,000€ available to the project. An agreement between Paris Observatory and UNSAAC now enables Peruvian students to study astronomy through online teaching.
Astronomy in post-apartheid South Africa
Authors: Whitelock Patricia Ann
Published: June 2011

Astronomy was one of the sciences earmarked for major support by South Africa's first democratically elected government in 1994. This was a very remarkable decision for a country with serious challenges in poverty, health and unemployment, but shows something of the long term vision of the new government. In this paper I give one astronomer's perception of the reasons behind the decision and some of its consequences.
Conveying astronomy to the public
Authors: Fierro Julieta
Published: June 2011

The International Year of Astronomy offers us a unique chance to carry out outreach projects in great scale and, to think about new ways to improve our efforts. In this paper I present a few considerations on my activity as a popularisation person. I address its importance and I will emphasize on radio, television and public lectures. I also stress certain ingredients I believe popularisation must include; it must be interesting, diverse, simple, pertinent, and be peer reviewed.
Non-Formal education in astronomy: The experience of the University the Carabobo
Authors: Falcón Nelson
Published: June 2011

Since 1995, the University the Carabobo, in Venezuela, has come developing a program of astronomical popularization and learning Astronomy using the Non formal education methods. A synopsis of the activities is presented. We will also discuss some conceptual aspects about the extension of the knowledge like supplementary function of the investigation and the university teaching. We illustrate the characteristics of the communication with an example of lectures and printed material. The efficiency of the heuristic arguments could be evaluated through a ethnology study. In that order of ideas, we show some images of the activities of astronomical popularization. We can see the population and great concurrence with chronological (and cultural) heterogeneity. We conclude that the Non formal education, structured with characteristic different to the usual educational instruction, constitutes a successful strategy in the diffusion and the communicating astronomy.
The “Nuits des étoiles” events (1991–2008) and their impact on the French astronomical leisure landscape
Authors: Vergnas Olivier Las , Piednoël Eric
Published: June 2011

The popular event Nuits des étoiles has become in France the summer encounter with the sky. More than 400 events are set up for three consecutive days each year: several thousands of voluntary organisers invite more and more people to observe the heavens and discover astronomy. Each summer, those collective star parties reach about one hundred thousand people, several millions of sky maps are printed and distributed by newspapers and the associated TV live program broadcast by France 2 channel interested 1 to 3 millions spectators. Since 1991, Nuits des étoiles has helped to develop organisations at the local level and increased the stakeholders' interest in general public awareness. It contributed in France to strengthen and professionalise an astronomical leisure offer.
“Astrophysique sur Mesure”, E-learning in Astronomy and Astrophysics
Authors: Mosser Benoît , Delsanti Audrey , Guillaume Damien , Balança Christian , Balkowski Chantal
Published: June 2011

“Astrophysique sur Mesure” (astrophysics made-to-measure) is a set of e-learning programmes started 4 years ago at the Paris Observatory. In order to deliver attractive and efficient programmes, we have added many multimedia tools to usual lectures: animations, Java applets. The programmes are presented on two different platforms. The first one offers the content of all the lectures in free access. A second platform with restricted access is provided to registered students taking part in the e-learning program and benefiting from the help of tutors. The development of these programs helps to increase the sphere of influence of astronomy taught at the Paris Observatory, hence to increase the presence of astronomy in various degree courses. Instead of teaching classical astronomy lectures to a happy few, we can bring astronomy and astrophysics to a wider audience.
Interactions between astronomical ephemerides and society
Authors: Arlot Jean-Eudes
Published: June 2011

Ephemerides are regularly made by astronomers for their own uses. However, the general public is also interested, as well as official organisms, because of the interactions of ephemerides with society. Astronomers in charge of the making of calendars and keeping the time are of great importance every day. Their calculations are also required for the positioning of ships and airplanes. Some ephemerides are also requested by the general public.
Galactic archaeology for amateur astronomers: RR Lyrae stars as tracers of the Milky Way formation
Authors: Carballo-Bello Julio A. , Martínez-Delgado David , Fliri Jürgen
Published: June 2011

Cosmological models predict that large galaxies like the Milky Way formed from the accretion of smaller stellar systems. The most spectacular of these merger events are stellar tidal streams, rivers of stars and dark matter that envelop the discs of spiral galaxies. We present a research project for a collaboration with amateur astronomers in the study of the formation process of our Galaxy. The main objective is the search for RR Lyrae variable stars in the known stellar streams (Sagitarius, Monoceros, Orphan, etc) a project that can be carried out using small telescopes. The catalogue of candidate variable stars were selected from SDSS data based in colour criteria and it will be sent to interested amateur astronomers who wish to participate in scientific research in one of the most active and competitive topics in Galactic astronomy.
Camille Flammarion's observatory: towards a revival
Authors: Morel P. , Pecker J.C. , Flammarion A. , Fuentes P. , Stépanoff C.A. , Sol R. , Dufour G. , Chaufour R. , Goury-Laffont J.
Published: June 2011

Camille Flammarion's observatory, located in Juvisy-sur-Orge in the suburbs of Paris, has been idle since 1962. Property of the Société Astronomique de France (SAF), it was made available to the city of Juvisy-sur-Orge since 1971, and contains a unique collection of objects and books currently being sorted out. The observatory is being restored by the SAF, thanks to the support of the city of Juvisy-sur-Orge, the French Académie des Sciences and the “Amis de Camille Flammarion” association. In 2006, the Maxime Goury Laffont foundation funded the refurbishment of the 240 mm refractor and in 2007 funds were obtained to restore the dome and central building. The main aim of the project is to make this historical place a popular observatory dedicated to astronomy and the sciences which Camille Flammarion enjoyed and contributed to. It constitutes a unique example in France of synergies linking associations, municipality, regional- and national-level institutions.
The TENPLA Project: Communicating Astronomy with the Public in Japan
Authors: Takanashi Naohiro , Hiramatsu Masaaki
Published: June 2011

The TENPLA project (pronounced as “ten-pla”, like a famous Japanese food “Tempura”) is designed to communicate Astronomy with the public in Japan. We have been working to suggest various ways to enjoy astronomy. We have organised star gazing parties, science cafés, and lectures. We have made many goodies which make people interested in astronomy (e.g. “Astronomical Toilet Paper”). We have also provided opportunities to communicate with each other for people who have interests in such activities. In this paper we present a broad overview of the TENPLA project.
Wishes to Die in Older People
Authors: Rurup M. L. , Deeg D. J. H. , Poppelaars J. L. , Kerkhof A. J. F. M. , Onwuteaka-Philipsen B. D.
Published: June 2011

Background: Death thoughts and wishes occur frequently among older people. In different European countries estimates of 10%–20% have been found. Aims: To determine the prevalence and associated factors of death thoughts and wishes among older people in The Netherlands. Methods: In The Netherlands 1794 people (58–98 years) were interviewed in 2005/2006 (Longitudinal Aging Study Amsterdam). Results: 81.3% reported never having death thoughts/wishes; 15.3% reported having had such thoughts/wishes; 3.4% reported currently having a wish to die and/or a weakened wish to continue living. Of those with a current wish to die, 67% had depressive symptoms (vs. 32% of people with death thoughts/wishes ever and 9% of people who never had had death thoughts/wishes), and 20% suffered from a depressive disorder (vs. 5% if death thoughts/wishes ever; 0.3% if never death thoughts/wishes). In a multivariate analysis, a current wish to die was associated with having depressive symptoms, a depressive disorder, lower perceived mastery, financial problems, loneliness, small network, involuntary urine loss, being divorced, and having a speech impediment. Conclusions: Practical implications for health-care professionals are that they should be aware that in certain situations older people are more likely to develop a wish to die, and that a wish to die does not necessarily mean that someone has a depressive disorder. Nevertheless, it should serve as a trigger to investigate and to treat depression if present.
Is the Emotional Response of Survivors Dependent on the Consequences of the Suicide and the Support Received?
Authors: Schneider Barbara , Grebner Kristin , Schnabel Axel , Georgi Klaus
Published: June 2011

Background: Despite numerous studies that have assessed emotional reactions of people bereaved by suicide, many questions in this field are not yet clarified. Aims: The purpose of the present study was to explore how emotional reactions of those bereaved by suicide depend on their gender, the relationship to the deceased, the consequences (“only negative,” “negative and positive,” “predominantly positive”) of the death for the bereaved and the professional support received. Methods: The relationship between emotional reactions and characteristics was assessed in 163 suicide bereaved. Most bereaved, including all the parents of the suicide victims, had experienced emotions that occurred so often and so strongly that they had disturbed everyday life. The most frequently reported emotions were guilt and depressed mood. Female gender and being parents or spouses were associated with increased risk for lack of energy. Furthermore, the emotions of the bereaved depended on the consequences of the suicide and the professional support received. Conclusions: Professional support might be particularly important for suicide bereaved.
Inequalities and Impact of Socioeconomic-Cultural Factors in Suicide Rates Across Italy
Authors: Pompili Maurizio , Innamorati Marco , Vichi Monica , Masocco Maria , Vanacore Nicola , Lester David , Serafini Gianluca , Tatarelli Roberto , De Leo Diego , Girardi Paolo
Published: June 2011

Background: Suicide is a major cause of premature death in Italy and occurs at different rates in the various regions. Aims: The aim of the present study was to provide a comprehensive overview of suicide in the Italian population aged 15 years and older for the years 1980–2006. Methods: Mortality data were extracted from the Italian Mortality Database. Results: Mortality rates for suicide in Italy reached a peak in 1985 and declined thereafter. The different patterns observed by age and sex indicated that the decrease in the suicide rate in Italy was initially the result of declining rates in those aged 45+ while, from 1997 on, the decrease was attributable principally to a reduction in suicide rates among the younger age groups. It was found that socioeconomic factors underlined major differences in the suicide rate across regions. Conclusions: The present study confirmed that suicide is a multifaceted phenomenon that may be determined by an array of factors. Suicide prevention should, therefore, be targeted to identifiable high-risk sociocultural groups in each country.
Suicide Attempts Among Depressed Inpatients with Depressive Disorder in a Malaysian Sample
Authors: Chan L. F. , Maniam T. , Shamsul A. S.
Published: June 2011

Background: Depressed inpatients constitute a high-risk population for suicide attempts. Aims: To describe the interactions of clinical and psychosocial risk factors influencing suicide attempts among a Malaysian sample of depressed inpatients. Methods: Seventy-five subjects were diagnosed with a depressive disorder according to the Structured Clinical Interview for DSM-IV Axis I Disorders-Clinical Version (SCID-CV). Data on suicide attempts, suicidal ideation (Scale for Suicidal Ideation, SSI), depression severity (Beck’s Depression Inventory, BDI), recent life-event changes (Social Readjustment Rating Scale, SRRS), sociodemographic and other relevant clinical factors were collected. Results: A third of the subjects presented after a current suicide attempt. Significant factors for a current suicide attempt were race, religion, recent life-event changes, suicidal ideation, and alcohol use disorder. Independent predictive risk factors for a current suicide attempt were Chinese race, recent marital separation, major mortgage or loans, and being newly diagnosed with depression. Any recent change in personal habits was shown to be a protective factor against current suicide attempt. Age and gender were nonsignificant factors. Conclusions: The findings are generally consistent with existing studies and highlight the role of psychosocial risk factors.
Western equatorial Pacific deep water carbonate chemistry during the Last Glacial Maximum and deglaciation: Using planktic foraminiferal Mg/Ca to reconstruct sea surface temperature and seafloor dissolution
Authors: Fehrenbacher Jennifer , Martin Pamela
Published: June 2011

We present a reconstruction of deep‐water carbonate saturation state (ΔCO32−) in the western equatorial Pacific for the Last Glacial Maximum (LGM) and deglaciation based on changes in the Mg/Ca ratio of planktic foraminifers with increased water depth. Our data suggest there have been changes in bottom water ΔCO32− over the past 25,000 years at water depths as shallow as 1.6 km. The ΔCO32− reconstruction for the LGM suggests ΔCO32− was similar or slightly higher than modern values between 1.6 and 2.0 km, shifting sharply to lower values (an average ∼30 μmol/kg lower) below 2.5 km. The shift in chemistry between 2.0 and 2.5 km supports a hypothesis that Pacific overturning circulation occurred deeper during the LGM with a slightly more ventilated water mass above 2.0 km. The data are not consistent with enhanced preservation in this region of the deep Pacific at depths greater than 2.5 km, suggesting that the long‐held view of better preservation throughout the glacial deep Pacific must be reevaluated. For the deglaciation, we have evidence of a ΔCO32− maximum that suggests enhanced deglacial preservation between 1.6 and 4.0 km in comparison to the Holocene and the LGM. The deglacial ΔCO32− was as much as 28 μmol/kg higher than modern between 1.6 and 4.0 km. Results suggest carbonate burial rates were 1.5 times greater during the deglacial than the over the past 5 kyr.
Occlusion of Cortical Ascending Venules Causes Blood Flow Decreases, Reversals in Flow Direction, and Vessel Dilation in Upstream Capillaries
Authors: Nguyen John , Nishimura Nozomi , Fetcho Robert N , Iadecola Costantino , Schaffer Chris B
Published: June 2011

The accumulation of small strokes has been linked to cognitive dysfunction. Although most animal models have focused on the impact of arteriole occlusions, clinical evidence indicates that venule occlusions may also be important. We used two-photon excited fluorescence microscopy to quantify changes in blood flow and vessel diameter in capillaries after occlusion of single ascending or surface cortical venules as a function of the connectivity between the measured capillary and the occluded venule. Clotting was induced by injuring the target vessel wall with femtosecond laser pulses. After an ascending venule (AV) occlusion, upstream capillaries showed decreases in blood flow speed, high rates of reversal in flow direction, and increases in vessel diameter. Surface venule occlusions produced similar effects, unless a collateral venule provided a new drain. Finally, we showed that AVs and penetrating arterioles have different nearest-neighbor spacing but capillaries branching from them have similar topology, which together predicted the severity and spatial extent of blood flow reduction after occlusion of either one. These results provide detailed insights into the widespread hemodynamic changes produced by cortical venule occlusions and may help elucidate the role of venule occlusions in the development of cognitive disorders and other brain diseases.
Ubiquitin-mediated internalization of connexin43 is independent of the canonical endocytic tyrosine-sorting signal
Authors: Catarino Steve , Ramalho José S. , Marques Carla , Pereira Paulo , Girão Henrique
Published: June 2011

Gap junctions are specialized cell–cell contacts that provide direct intercellular communication between eukaryotic cells. The tyrosine-sorting signal (YXXØ), present at amino acids 286–289 of Cx43 (connexin43), has been implicated in the internalization of the protein. In recent years, ubiquitination of Cx43 has also been proposed to regulate gap junction intercellular communication; however, the underlying mechanism and molecular players involved remain elusive. In the present study, we demonstrate that ubiquitinated Cx43 is internalized through a mechanism that is independent of the YXXØ signal. Indeed, expression of a Cx43–Ub (ubiquitin) chimaera was shown to drive the internalization of a mutant Cx43 in which the YXXØ motif was eliminated. Immunofluorescence, cycloheximide-chase and cell-surface-protein biotinylation experiments demonstrate that oligomerization of Cx43–Ub into hemichannels containing wild-type Cx43 or mutant Cx43Y286A is sufficient to drive the internalization of the protein. Furthermore, the internalization of Cx43 induced by Cx43–Ub was shown to depend on its interaction with epidermal growth factor receptor substrate 15.
Multiobjective synchronization of coupled systems
Authors: Tang Yang , Wang Zidong , Wong W. K. , Kurths Jürgen , Fang Jian-an
Published: June 2011

In this paper, multiobjective synchronization of chaotic systems is investigated by especially simultaneously minimizing optimization of control cost and convergence speed. The coupling form and coupling strength are optimized by an improved multiobjective evolutionary approach that includes a hybrid chromosome representation. The hybrid encoding scheme combines binary representation with real number representation. The constraints on the coupling form are also considered by converting the multiobjective synchronization into a multiobjective constraint problem. In addition, the performances of the adaptive learning method and non-dominated sorting genetic algorithm-II as well as the effectiveness and contributions of the proposed approach are analyzed and validated through the Rössler system in a chaotic or hyperchaotic regime and delayed chaotic neural networks.
The dynamics of network coupled phase oscillators: An ensemble approach
Authors: Barlev Gilad , Antonsen Thomas M. , Ott Edward
Published: June 2011

We consider the dynamics of many phase oscillators that interact through a coupling network. For a given network connectivity we further consider an ensemble of such systems where, for each ensemble member, the set of oscillator natural frequencies is independently and randomly chosen according to a given distribution function. We then seek a statistical description of the dynamics of this ensemble. Use of this approach allows us to apply the recently developed ansatz of Ott and Antonsen [Chaos 18, 037113 (2008)] to the marginal distribution of the ensemble of states at each node. This, in turn, results in a reduced set of ordinary differential equations determining these marginal distribution functions. The new set facilitates the analysis of network dynamics in several ways: (i) the time evolution of the reduced system of ensemble equations is much smoother, and thus numerical solutions can be obtained much faster by use of longer time steps; (ii) the new set of equations can be used as a basis for obtaining analytical results; and (iii) for a certain type of network, a reduction to a low dimensional description of the entire network dynamics is possible. We illustrate our approach with numerical experiments on a network version of the classical Kuramoto problem, first with a unimodal frequency distribution, and then with a bimodal distribution. In the latter case, the network dynamics is characterized by bifurcations and hysteresis involving a variety of steady and periodic attractors.
Modal and non-modal stability of particle-laden channel flow
Authors: Klinkenberg Joy , de Lange H. C. , Brandt Luca
Published: June 2011

Modal and non-modal linear stability analysis of channel flow with a dilute particle suspension is presented where particles are assumed to be solid, spherical, and heavy. The two-way coupling between particle and fluid flow is therefore modeled by the Stokes drag only. The results are presented as function of the particle relaxation time and mass fraction. First, we consider exponentially growing perturbations and extend previous findings showing the potential for a significant increase of the critical Reynolds number. The largest stabilization is observed when the ratio between the particle relaxation time and the oscillation period of the wave is of order one. By examining the energy budget, we show that this stabilization is due to the increase of the dissipation caused by the Stokes drag. The observed stabilization has led to the hypothesis that dusty flows can be more stable. However, transition to turbulence is most often subcritical in canonical shear flows where non-modal growth mechanisms are responsible for the initial growth of external disturbances. The non-modal analysis of the particle-laden flow, presented here for the first time, reveals that the transient energy growth is, surprisingly, increased by the presence of particles, in proportion to the particle mass fraction. The generation of streamwise streaks via the lift-up mechanism is still the dominant disturbance-growth mechanism in the particle laden flow; the length scales of the most dangerous disturbances are unaffected, while the initial disturbance growth can be delayed. These results are explained in terms of a dimensionless parameter relating the particle relaxation time to the time scale of the instability. The presence of a dilute solid phase therefore may not always work as a flow-control strategy for maintaining the flow as laminar. Despite the stabilizing effect on modal instabilities, non-modal mechanisms are still strong in internal flows seeded with heavy particles. Our results indicate that the initial stages of transition in dilute suspensions of small particles are similar to the stages in a single phase flow.
Improvement of high-frequency characteristics of Z-type hexaferrite by dysprosium doping
Authors: Mu Chunhong , Liu Yingli , Song Yuanqiang , Wang Liguo , Zhang Huaiwu
Published: June 2011

Z-type hexaferrite has great potential applications as anti-EMI material for magnetic devices in the GHz region. In this work, Dy-doped Z-type hexaferrites with nominal stoichiometry of Ba3Co2DyxFe24−xO41 (x = 0.0, 0.05, 0.5, 1.0) were prepared by an improved solid-state reaction method. The effects of rare earth oxide (Dy2O3) addition on the phase composition, microstructure and electromagnetic properties of the ceramics were investigated. Structure and micromorphology characterizations indicate that certain content of Dy doping will cause the emergence of the second phase Dy3Fe5O12 at the grain boundaries of the majority phase Z-type hexaferrite, due to which the straightforward result is the grain refinement during the successive sintering process. Permeability spectra measurements show that the initial permeability reaches its maximum of 17 at 300 MHz with x = 0.5, while the cutoff frequency keeps above 800 MHz. The apparent specific anisotropy field HK of Dy-doped Z-type hexaferrites decreases with x increasing. The relationships among phase composition, grain size, permeability spectra, and anisotropy are theoretically investigated, and according to the analysis, Dy doping effects on its magnetic properties can be well explained and understood.
Generalizations of the classical Yang-Baxter equation and ${\mathcal O}$O-operators
Authors: Bai Chengming , Guo Li , Ni Xiang
Published: June 2011

Tensor solutions (r-matrices) of the classical Yang-Baxter equation (CYBE) in a Lie algebra, obtained as the classical limit of the R-matrix solution of the quantum Yang-Baxter equation, is an important structure appearing in different areas such as integrable systems, symplectic geometry, quantum groups, and quantum field theory. Further study of CYBE led to its interpretation as certain operators, giving rise to the concept of \documentclass[12pt]{minimal}\begin{document}${{\mathcal O}}$\end{document}O-operators. The \documentclass[12pt]{minimal}\begin{document}${\mathcal O}$\end{document}O-operators were in turn interpreted as tensor solutions of CYBE by enlarging the Lie algebra [Bai, C., “A unified algebraic approach to the classical Yang-Baxter equation,” J. Phys. A: Math. Theor. 40, 11073 (2007)]10.1088/1751-8113/40/36/007. The purpose of this paper is to extend this study to a more general class of operators that were recently introduced [Bai, C., Guo, L., and Ni, X., “Nonabelian generalized Lax pairs, the classical Yang-Baxter equation and PostLie algebras,” Commun. Math. Phys. 297, 553 (2010)]10.1007/s00220-010-0998-7 in the study of Lax pairs in integrable systems. Relations between \documentclass[12pt]{minimal}\begin{document}${\mathcal O}$\end{document}O-operators, relative differential operators, and Rota-Baxter operators are also discussed.
The effects of strong temperature anisotropy on the kinetic structure of collisionless slow shocks and reconnection exhausts. I. Particle-in-cell simulations
Authors: Liu Yi-Hsin , Drake J. F. , Swisdak M.
Published: June 2011

A 2-D Riemann problem is designed to study the development and dynamics of the slow shocks that are thought to form at the boundaries of reconnection exhausts. Simulations are carried out for varying ratios of normal magnetic field to the transverse upstream magnetic field (i.e., propagation angle with respect to the upstream magnetic field). When the angle is sufficiently oblique, the simulations reveal a large firehose-sense (P∥>P⊥) temperature anisotropy in the downstream region, accompanied by a transition from a coplanar slow shock to a non-coplanar rotational mode. In the downstream region the firehose stability parameter ɛ=1-μ0(P∥-P⊥)/B2 tends to plateau at 0.25. This balance arises from the competition between counterstreaming ions, which drive ɛ down, and the scattering due to ion inertial scale waves, which are driven unstable by the downstream rotational wave. At very oblique propagating angles, 2-D turbulence also develops in the downstream region.
Adaptive bridge control strategy for opinion evolution on social networks
Authors: Qian Cheng , Cao Jinde , Lu Jianquan , Kurths Jürgen
Published: June 2011

In this paper, we present an efficient opinion control strategy for complex networks, in particular, for social networks. The proposed adaptive bridge control (ABC) strategy calls for controlling a special kind of nodes named bridge and requires no knowledge of the node degrees or any other global or local knowledge, which are necessary for some other immunization strategies including targeted immunization and acquaintance immunization. We study the efficiency of the proposed ABC strategy on random networks, small-world networks, scale-free networks, and the random networks adjusted by the edge exchanging method. Our results show that the proposed ABC strategy is efficient for all of these four kinds of networks. Through an adjusting clustering coefficient by the edge exchanging method, it is found out that the efficiency of our ABC strategy is closely related with the clustering coefficient. The main contributions of this paper can be listed as follows: (1) A new high-order social network is proposed to describe opinion dynamic. (2) An algorithm, which does not require the knowledge of the nodes’ degree and other global/local network structure information, is proposed to control the “bridges” more accurately and further control the opinion dynamics of the social networks. The efficiency of our ABC strategy is illustrated by numerical examples. (3) The numerical results indicate that our ABC strategy is more efficient for networks with higher clustering coefficient.
On the behavior of Brønsted-Evans-Polanyi relations for transition metal oxides
Authors: Vojvodic A. , Calle-Vallejo F. , Guo W. , Wang S. , Toftelund A. , Studt F. , Martínez J. I. , Shen J. , Man I. C. , Rossmeisl J. , Bligaard T. , Nørskov J. K. , Abild-Pedersen F.
Published: June 2011

Versatile Brønsted-Evans-Polanyi (BEP) relations are found from density functional theory for a wide range of transition metal oxides including rutiles and perovskites. For oxides, the relation depends on the type of oxide, the active site, and the dissociating molecule. The slope of the BEP relation is strongly coupled to the adsorbate geometry in the transition state. If it is final state-like the dissociative chemisorption energy can be considered as a descriptor for the dissociation. If it is initial state-like, on the other hand, the dissociative chemisorption energy is not suitable as descriptor for the dissociation. Dissociation of molecules with strong intramolecular bonds belong to the former and molecules with weak intramolecular bonds to the latter group. We show, for the prototype system La-perovskites, that there is a “cyclic” behavior in the transition state characteristics upon change of the active transition metal of the oxide.
Anomalies in supercooled NaCl aqueous solutions: A microscopic perspective
Authors: Longinotti M. Paula , Carignano Marcelo A. , Szleifer Igal , Corti Horacio R.
Published: June 2011

In this work we studied the effect of NaCl on the thermodynamic and dynamic properties of supercooled water, for salt concentrations between 0.19 and 1.33 mol kg−1, using molecular dynamic simulations for TIP5P/E water model and ion parameters specially designed to be used in combination with this potential. We studied the isobaric heat capacity (Cp) temperature dependence and observed a maximum in Cp, occurring at Tm, that moves to lower temperature values with increasing salt concentration. Many characteristic changes were observed at scaled temperature T/Tm ∼ 0.96, namely a minimum in the density of the system, a reduction of the slope of the number of hydrogen bonds vs. temperature, and a crossover from Vogel-Tamman-Fulcher to Arrhenius dynamics. Finally, at low temperatures we observed that water dynamics become heterogeneous with an apparently common relationship between the fraction of immobile molecules and T/Tm for all studied systems.
A tunable terahertz filter and its switching properties in terahertz region based on a defect mode of a metallic photonic crystal
Authors: Kim Yong Sung , Lin Shawn-Yu , Wu Hsin-Ying , Pan Ru-Pin
Published: June 2011

We theoretically investigate and discuss an electrically tunable terahertz filter design and its optical switching properties based on the defect mode of a woodpile metallic photonic crystal (MPC). The model filter design is based on a dual use of an MPC as a resonator and as electrodes with a liquid crystal used as a defect layer. The static and the dynamic responses of a realistic liquid crystal are obtained using the Oseen–Frank elastic continuum theory, and the corresponding transmission spectra are calculated using an analytic modal expansion method combined with a transfer-matrix method. The tuning range of f = 1.430∼1.577 THz and the order of milliseconds switching property are observed in our design.
Dielectrophoretic manipulation of ribosomal RNA
Authors: Giraud Gerard , Pethig Ronald , Schulze Holger , Henihan Grace , Terry Jonathan G. , Menachery Anoop , Ciani Ilenia , Corrigan Damion , Campbell Colin J. , Mount Andrew R. , Ghazal Peter , Walton Anthony J. , Crain Jason , Bachmann Till T.
Published: June 2011

The manipulation of ribosomal RNA (rRNA) extracted from E. coli cells by dielectrophoresis (DEP) has been demonstrated over the range of 3 kHz–50 MHz using interdigitated microelectrodes. Quantitative measurement using total internal reflection fluorescence microscopy of the time dependent collection indicated a positive DEP response characterized by a plateau between 3 kHz and 1 MHz followed by a decrease in response at higher frequencies. Negative DEP was observed above 9 MHz. The positive DEP response below 1 MHz is described by the Clausius–Mossotti model and corresponds to an induced dipole moment of 3300 D with a polarizability of 7.8×10−32 F m2. The negative DEP response above 9 MHz indicates that the rRNA molecules exhibit a net moment of −250 D, to give an effective permittivity value of 78.5 ε0, close to that of the aqueous suspending medium, and a relatively small surface conductance value of ∼0.1 nS. This suggests that our rRNA samples have a fairly open structure accessible to the surrounding water molecules, with counterions strongly bound to the charged phosphate groups in the rRNA backbone. These results are the first demonstration of DEP for fast capture and release of rRNA units, opening new opportunities for rRNA-based biosensing devices.
How the surface energy of ultra-thin CuF2 film as anode buffer layer affect the organic light-emitting devices?
Authors: Chen Yu-Cheng , Kao Po-Ching , Fang Ying-Chien , Huang Hsin-Hsuan , Chu Sheng-Yuan
Published: June 2011

The effect of surface energy on organic light-emitting device performance was demonstrated by depositing an ultra-thin CuF2 buffer layer on indium tin oxide (ITO) substrates, followed by ultraviolet (UV)-ozone treatment. An optimal thickness UV-ozone treated CuF2 (4 nm)/ITO anode significantly improved device performance. Work function estimates from X-ray photoelectron measurements suggested that both pristine and UV-ozone treated CuF2/ITO anodes had no hole injection barrier. Measurements of energy band, surface energy and surface polarity indicated device improvement came from the simultaneous increase in work function and surface energy of ITO by adding treated CuF2 film between ITO and the hole-transporting layer.
Brownian dynamics simulation of a model simple electrolyte in solvents of low dielectric constant
Authors: Yamaguchi T. , Akatsuka T. , Koda S.
Published: June 2011

Brownian dynamics simulations are performed to investigate the ionic transport of model simple electrolytes, in which ions are interacting with each other through the repulsive core and Coulombic interactions. The equivalent conductivity and self-diffusion coefficient show minima as the function of the number density of ions when the dielectric constant of the solvent is low. Although the minimum of the former is in harmony with various experiments, no experiment has ever been reported on that of the latter. The analysis of time-dependent transport coefficients reveals that the presence of the minima is ascribed to the slow dynamics, rather than to static association models. The inclusion of a model function that resembles the short-range part of the potential of mean force induced by solvent affects the transport coefficients qualitatively, which suggests the importance of solvent-induced potential of mean force in the conduction mechanism of electrolytes in solvents of low dielectric constant.
Brueckner doubles coupled cluster method with the polarizable continuum model of solvation
Authors: Caricato Marco , Scalmani Giovanni , Frisch Michael J.
Published: June 2011

We present the theory and implementation for computing the (free) energy and its analytical gradients with the Brueckner doubles (BD) coupled cluster method in solution, in combination with the polarizable continuum model of solvation (PCM). The complete model, called PTED, and an efficient approximation, called PTE, are introduced and tested with numerical examples. Implementation details are also discussed. A comparison with the coupled-cluster singles and doubles CCSD-PCM-PTED and CCSD-PCM-PTE schemes, which use Hartree-Fock (HF) orbitals, is presented. The results show that the two PTED approaches are mostly equivalent, while BD-PCM-PTE is shown to be superior to the corresponding CCSD scheme when the HF reference wave function is unstable. The BD-PCM-PTE scheme, whose computational cost is equivalent to gas phase BD, is therefore a promising approach to study molecular systems with complicated electronic structure in solution.
Electron holographic tomography for mapping the three-dimensional distribution of electrostatic potential in III-V semiconductor nanowires
Authors: Wolf D. , Lichte H. , Pozzi G. , Prete P. , Lovergine N.
Published: June 2011

Electron holographic tomography (EHT), the combination of off-axis electron holography with electron tomography, is a technique, which can be applied to the quantitative 3-dimensional (3D) mapping of electrostatic potential at the nanoscale. Here, we show the results obtained in the EHT investigation of GaAs and GaAs-AlGaAs core-shell nanowires grown by Au-catalysed metalorganic vapor phase epitaxy. The unique ability of EHT of disentangling the materials mean inner potential (MIP) from the specimen projected thickness allows reconstruction of the nanowire 3D morphology and inner compositional structure as well as the measurement of the MIP.
Shear-enhanced adhesiveless transfer printing for use in deterministic materials assembly
Authors: Carlson Andrew , Kim-Lee Hyun-Joon , Wu Jian , Elvikis Paulius , Cheng Huanyu , Kovalsky Anton , Elgan Steven , Yu Qingmin , Ferreira Placid M. , Huang Yonggang , Turner Kevin T. , Rogers John A.
Published: June 2011

This letter describes the physics and application of an approach to transfer printing that utilizes targeted shear loading to modulate stamp adhesion in a controlled and repeatable fashion. Experimental measurements of pull-off forces as functions of shear and stamp dimension reveal key scaling properties and provide a means for comparison to theory and modeling. Examples of printed structures in suspended and multilayer configurations demonstrate some capabilities in micro/nanoscale materials assembly.