bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and Sterilization of Mosquito Net Mesh for Humanitarian Inguinal Hernioplasty
Authors: Stephenson Brian M. , Kingsnorth Andrew N.
Published: June 2011

Background

Inguinal hernia repair is one of the most commonly performed operations in Africa. Prosthetic repair with commercially available mesh is generally considered too expensive in low‐income countries. Elective groin hernia surgery with mosquito net mesh has recently been described. However, can mesh sterility in resource‐poor countries be guaranteed to ensure both effectiveness and safety?

Methods

Copolymer and polyester mosquito net mesh were steam‐sterilized at varying temperatures. PubMed and EMBASE were searched using key words, MeSH, and subject headings (mosquito net mesh, mesh sterilization, inguinal hernia repair).

Results

Copolymer mosquito net mesh manufactured in India can be safely sterilized at lower (less “strict”) temperatures (121°C) than those usually demanded by advanced health care systems (134°C). The literature search revealed a number of case series but all with limited follow‐up. Available data, however, support the use of this type mosquito net mesh in the elective repair of hernias.

Conclusions

Hernia repair with mosquito net mesh is a plausible, safe, cost‐effective alternative in low‐income countries. Sterilization in steam autoclaves that have accurate temperature control is required.
Impact of physical activity and sedentary behaviour on fall risks in older people: a systematic review and meta-analysis of observational studies
Authors: Thibaud Marie , Bloch Frédéric , Tournoux-Facon Caroline , Brèque Cyril , Rigaud Anne Sophie , Dugué Benoît , Kemoun Gilles
Published: June 2011

The objective of this work was to summarise and evaluate the evidence showing that physical activity is a protector factor as regards falls in older people. Relevant studies were identified through a systematic search in the MEDLINE and Cochrane Library, under the keywords of accidental fall/numerical data and risk factors, and with the bibliographies of retrieved papers. The combined odds ratio (OR) [95% confidence interval] for physical activity was 0.75 [0.64, 0.88] with moderate heterogeneity (I
2 = 33%). For fall injury, it was 0.59 [0.47, 0.74] and, for falls in general, it rose to 0.94 [0.76, 1.17] with nil heterogeneity. The combined OR for sedentary factors was 1.14 [1.10, 1.82] with moderate heterogeneity (I
2 = 36%). Regular physical activity in daily life yields significant reduction in falls in older people, especially falls with injuries.
Onset of secondary instabilities on the zigzag instability in stratified fluids
Authors: AUGIER PIERRE , BILLANT PAUL
Published: June 2011

Recently, Deloncle, Billant & Chomaz (J. Fluid Mech., vol. 599, 2008, p. 229) and Waite & Smolarkiewicz (J. Fluid Mech., vol. 606, 2008, p. 239) have performed numerical simulations of the nonlinear evolution of the zigzag instability of a pair of counter-rotating vertical vortices in a stratified fluid. Both studies report the development of a small-scale secondary instability when the vortices are strongly bent if the Reynolds number Re is sufficiently high. However, the two papers are at variance about the nature of this secondary instability: it is a shear instability according to Deloncle et al. (J. Fluid Mech., vol. 599, 2008, p. 229) and a gravitational instability according to Waite & Smolarkiewicz (J. Fluid Mech., vol. 606, 2008, p. 239). They also profoundly disagree about the condition for the onset of the secondary instability: ReF2h > O(1) according to the former or ReFh > 80 according to the latter, where Fh is the horizontal Froude number. In order to understand the origin of these discrepancies, we have carried out direct numerical simulations of the zigzag instability of a Lamb–Chaplygin vortex pair for a wide range of Reynolds and Froude numbers. The threshold for the onset of a secondary instability is found to be ReF2h ≃ 4 for Re ≳ 3000 and ReFh = 80 for Re ≲ 1000 in agreement with both previous studies. We show that the scaling analysis of Deloncle et al. (J. Fluid Mech., vol. 599, 2008, p. 229) can be refined to obtain a universal threshold: (Re − Re0)F2h ≃ 4, with Re0 ≃ 400, which works for all Re. Two different regimes for the secondary instabilities are observed: when (Re − Re0)F2h ≃ 4, only the shear instability develops while when (Re − Re0)F2h ≫ 4, both shear and gravitational instabilities appear almost simultaneously in distinct regions of the vortices. However, the shear instability seems to play a dominant role in the breakdown into small scales in the range of parameters investigated.
Perturbations of the coupled Jeffery–Stokes equations
Authors: MONTGOMERY-SMITH STEPHEN
Published: June 2011

This paper seeks to provide clues as to why experimental evidence for the alignment of slender fibres in semi-dilute suspensions under shear flows does not match theoretical predictions. This paper posits that the hydrodynamic interactions between the different fibres that might be responsible for the deviation from theory, can at least partially be modelled by the coupling between Jeffery's equation and Stokes' equation. It is proposed that if the initial data are slightly non-uniform, in that the probability distribution of the orientation has small spatial variations, then there is feedback via Stokes' equation that causes these non-uniformities to grow significantly in short amounts of time, so that the standard uncoupled Jeffery's equation becomes a poor predictor when the volume ratio of fibres to fluid is not extremely low. This paper provides numerical evidence, involving spectral analysis of the linearization of the perturbation equation, to support this theory.
Was Barth a pro-Nicene theologian? Reflections onNicaea and its legacy
Authors: Molnar Paul D.
Published: June 2011

If this very weighty and important book did nothing else than establish the fact for modern systematic theology that the trinitarian theology of the fourth century cannot be understood properly by dividing Eastern from Western theology with the usual statement that the former begins with the three persons and moves towards the divine unity while the latter begins with the divine unity and moves towards the three persons, then something truly significant would have been accomplished (Nicaea, pp. 52, 384). Why? Because then one would not be able to trace a supposed modalist tendency directly from Augustine through much Western theology to contemporary theologians such as Barth in order to argue for a view of God's triunity which actually could undermine the full divinity of each of the persons of the Trinity who in reality exist eternally as three persons, one being. Consider, for instance, the remark made by Ted Peters that ‘There is no inherent reason for assuming that the three persons have to be identical or equal in nature.’ If one studies the development of fourth-century trinitarian theology, I think one would find many reasons to insist that the three persons are in fact equal in nature, among which are that any other assertion would undermine the divinity of the Son, lead to some sort of subordinationism or adoptionism (what Barth called Ebionite christology), and would ultimately strip the Gospel of its saving power.
Causal commutative arrows
Authors: LIU HAI , CHENG ERIC , HUDAK PAUL
Published: June 2011

Arrows are a popular form of abstract computation. Being more general than monads, they are more broadly applicable, and, in particular, are a good abstraction for signal processing and dataflow computations. Most notably, arrows form the basis for a domain-specific language calledYampa, which has been used in a variety of concrete applications, including animation, robotics, sound synthesis, control systems, and graphical user interfaces. Our primary interest is in better understanding the class of abstract computations captured by Yampa. Unfortunately, arrows are not concrete enough to do this with precision. To remedy this situation, we introduce the concept ofcommutative arrowsthat capture a noninterference property of concurrent computations. We also add aninitoperator that captures the causal nature of arrow effects, and identify its associated law. To study this class of computations in more detail, we define an extension to arrows calledcausal commutative arrows(CCA), and study its properties. Our key contribution is the identification of a normal form for CCA calledcausal commutative normal form(CCNF). By defining a normalization procedure, we have developed an optimization strategy that yields dramatic improvements in performance over conventional implementations of arrows. We have implemented this technique in Haskell, and conducted benchmarks that validate the effectiveness of our approach. When compiled with the Glasgow Haskell Compiler (GHC), the overall methodology can result in significant speedups.
The role of astronomy in society and culture
Authors: Valls-Gabaud David , Boksenberg Alexander
Published: June 2011

As an ancient and multidisciplinary field, astronomy is an ambassador for all sciences. Astronomy's broad appeal, whether from its cultural interest of our place in the universe, or its practical aims such as sea- or space navigation, is well recorded in history from ancient to modern times, and sky-awareness, more generally, began prehistorically. Astronomy's perceived role and purpose has continually developed over the ages. In all, astronomy is not to be viewed as a narrow subject operating in isolation but one that has contributed comprehensively to the advancement of society.
Bosscha Observatory: Challenges as a scientific heritage of astronomy in Indonesia
Authors: Epifania Priscilla , Mumpuni Emanuel Sungging
Published: June 2011

With over 80 years of existence, Bosscha Observatory in Lembang, West Java, Indonesia, still stands as one of the largest observatories that is registered by International Astronomical Union in the South East Asia region. Since first commissioned by the NISV (Netherlands Indische Sterrenkundige Vereeniging), Bosscha Observatory had played a major role in astronomy, particularly in research and observational activities in the southern hemisphere. But the current development has produced a serious impact on Bosscha Observatory, both tangible and intangible. With the challenges Bosscha Observatory faced the past decades, what can be done in the future to conserve not only the tangible value but most importantly the intangible value it embraces for the scientific development? This paper emphasizes its values, and opens some perspectives and ideas for conserving a (candidate to) Astronomy and World Heritage site. This important issue of how to best preserve the scientific value of this scientific heritage it embodied is discussed in some detail.
Astronomie, «arts» et artistes
Authors: Débarbat Suzanne
Published: June 2011

En 1665, Adrien Auzout (1622-1691) figure parmi les membres des cercles scientifiques qui fleurissent en France depuis une trentaine d'années. Une comète est apparue l'année précédente et il adresse à Louis XIV son «Ephéméride du Comète» [sic] correspondant à cette voyageuse. Cette épître permet de voir combien art et science sont pour lui étroitement associés. L'observatoire Royal créé deux ans plus tard illustrera cette interaction comme le montre l'examen de ses collections.
The sky entities as represented in African literature
Authors: Urama Evelyn N.
Published: June 2011

Astronomical observations used by the ancient people of Africa were developed out of the people's desire to have concrete manifestations of their gods and religious beliefs as well as for time-keeping – day, night and calendar for agricultural and festive seasons. The sky entities (the solar and stellar systems) observed become part of the lives and events here on Earth and so are also part of the context of African literature. This paper examines the ways in which different African peoples have reflected on the role of the sky entities in their literature.
Hebrew names of the planets
Authors: Zucker Shay
Published: June 2011

I review in this paper the basic Hebrew planetary terminology. To complete the picture I accompany it with some historical and cultural context, and compare it to the planetary terminology in Arabic, the most widely spoken Semitic language.
Public perception of astronomers Revered, reviled and ridiculed
Authors: West Michael J.
Published: June 2011

Society's view of astronomers has changed over time and from culture to culture. This review discusses some of the many ways that astronomers have been perceived by their societies and suggests ways that astronomers can influence public perception of ourselves and our profession in the future.
The magnificent night sky — why it must be protected from light pollution
Authors: Wainscoat Richard J.
Published: June 2011

The view of the night sky from most of the populated regions of Earth is now seriously compromised by light pollution. An entire generation of citizens is now growing up without ever having the opportunity to gaze upon the magnificent night sky from a dark location. Much of modern astronomy involves study of faint objects, often with brightnesses similar to or fainter than the night sky. Astronomers are therefore extremely vulnerable to increases in sky brightness from light pollution. Despite their remote locations, the dark night skies over the major optical observatories are increasingly threatened by growth of artificial light at night.
Astronomy for international development
Authors: Miley George
Published: June 2011

This review deals with the importance of astronomy for international development a nd capacity building. I shall summarize the present global state of astronomical research and education and describe current global astronomy education and development programs being carried out by the IAU and others. A decadal strategic plan will be described that envisages a substantial increase in IAU education and development activities during the next decade.
Using Videoconferencing for Elementary/Secondary Teacher Professional Development
Authors: Hemenway Mary Kay , Wetzel Marc , Rood Magdalena , Roberts-Gray Cynthia , Preston Sandra
Published: June 2011

Working within a large geographic area, McDonald Observatory lacks the resources to send staff to present professional development workshops to teachers – and only limited numbers of teachers have the resources to attend workshops at our observatory. Our solution is the development of a new program to bring the workshop to teachers in their own communities through videoconferencing. Each workshop location has a co-facilitator who prepared for his/her duties through an orientation/training session held at McDonald Observatory. At the observatory, they experienced a variety of activities and selected the ones most suitable for the grade-levels of the teachers in their region; they recruit the teachers for the local workshop. Each videoconference session includes pre/post assessment of the participants, an interactive videoconference with an expert presenter, and assistance from the co-facilitator who manages the materials and assists with the activities. Through use of this technology, we expect to reach 500 teachers. An independent evaluator is preparing formative and summative evaluation for the project.
Some remarks on a current study involving preservice elementary teachers and some basic astronomical phenomena
Authors: Gangui Alejandro , Iglesias María , Quinteros Cynthia
Published: June 2011

Recent studies have shown that not only primary school students but also their future teachers reach science courses with pre-constructed and consistent models of the world surrounding them. These ideas include many misconceptions which turn out to be robust and hence make difficult an appropriate teaching-learning process. We have designed some tools (and show here results with a questionnaire) that proved helpful in putting in evidence some of the most frequently used alternative models on a few basic astronomical notions. We have tested this questionnaire with preservice elementary teachers from various normal schools in Buenos Aires and made a first analysis of the results. The collection of data recovered so far shows that some non-scientific conceptions are indeed part of the prospective teachers' (scientific) background and, therefore, that the issue deserves special attention during their formal training.
Black Holes, Quasars, Blazars, and all that. . . How to explain them to a lay audience?
Authors: Hamidani Hamid , Mimouni Jamal
Published: June 2011

The popularisation of science is central to the culture of the citizen, and if astronomy make poets dream (and many others), astrophysics attracts young and old talents to science. To reveal in simple terms the stellar bestiary from the black holes to the quasars proceeds along this line. Black hole is still the object which is subject to most questions in any public talk on astronomy. How indeed does contemporary physics link the black hole, this stellar gravitational tomb, with the quasar, a galaxy gone mad? The tale is worth telling and makes indeed a beautiful story for contemporary young audience. Can it be told to our high school students with their modest scientific background? This is what we intend to do in this paper, spicing the sauce at the end with some new insights on the unified model of AGN.
Planetariums in the world
Authors: Faidit Jean-Michel
Published: June 2011

Modern planetaria achieved in 1923 a synthesis between planetaries and stellariums. In 2009, there are nearly 3000 planetariums all over the world, mainly in developed countries. We present here a brief historical and statistical analysis of this development.
Gathering the forgotten voices: an oral history of the CFHT's early years
Authors: Laychak Mary Beth , Bryson Liz
Published: June 2011

They came to the Big Island from as far away as Murrumbeena, Australia, and as near by as Hilo, Hawaii. They were progeny of Scottish coal miners, French physicists, Chicago truck drivers, Japanese samurai and Big Island cane workers. Together, these men and women would build and commission one of the most dynamic and productive 3.6 meter telescopes in the world that remains in the forefront of science and technology. The CFHT oral history DVD preserves the stories of the first decade and a half of the observatory.
The Cosmology Gallery: Unity through diversity in a vast and awe-inspiring universe.
Authors: Goldsmith John
Published: June 2011

Scientists, artists, religious and cultural leaders have come together to create the Cosmology Gallery at the Gravity Discovery Centre (GDC) located 70 km north of Perth, Western Australia. The Cosmology Gallery exhibitions include the multicultural cosmology artworks, Celestial Visions astronomical photography exhibition and the Timeline of the Universe. The multicultural cosmology artworks are new artworks inspired by Australian Indigenous, Christian, Buddhist, Islamic, Hindu, scientific and technological perspectives of the universe. The Celestial Visions exhibition features astronomical events above famous landmarks, including Stonehenge and the Pyramids. The AUD 400,000+ project was funded by Lotterywest, Western Australia and the Cosmology Gallery was officially opened in July 2008 by the Premier of Western Australia.
The sky as a laboratory: an educational project of the Department of Astronomy of the University of Padova
Authors: Ciroi S. , Di Mille F. , Rafanelli P.
Published: June 2011

“The Sky as a Laboratory” is an educational project of the Department of Astronomy of the University of Padova aimed to give students a physical approach to astronomy and astrophysics. It is a regional program designed to improve science education in the last two grades of high school, by creating cooperation between scientists and teachers. Currently it is present in 30 high schools around all provinces of the region of Veneto in the North-East of Italy. The close involvement in the didactical activities of high schools teachers is without any doubt the winning strategy of the project. Their enthusiastic participation to teaching and organising activities attracts each year the attention for sciences of an increasing number of students and suggests new ideas for future educational activities.
Big questions about the universe
Authors: Stavinschi Magda
Published: June 2011

Astronomy is not only a branch of science but also an important part of the culture and civilisations of peoples. Starting with archeoastronomy to the present day, it has always contributed to a better understanding of life, of humanity. After 400 years of modern astronomy, it still addresses major problems such as: Why there is something rather than nothing? Why is nature comprehensible to humans? How is cosmos related to humanity? Do multiverses exist? Is there life on other planets? Are we alone in the universe? Does the universe have a beginning? If so, what does it mean? How did the universe originate? All these questions are a challenge for interdisciplinary and transdisciplinary investigations, for philosophers, physicists, cosmologists, mathematicians, theologians. The new insights gained by pursuing in depth these common investigations will shape the society we live in and have important consequences on the future we are creating.
Double stars: a synergy between amateur and professional astronomers
Authors: Agati Jean-Louis , Bonneau Daniel , Caille Sébastien , Couteau Paul , Debackère André , Dommanget Jean , Durand Pierre , Gili René , Losse Florent , Manté René , Mauroy Florence , Morlet Guy , Salaman Maurice , Soulié Edgar , Thorel Jean-Claude , Thorel Yvonne , Verhas Pierre
Published: June 2011

In the field of visual double stars, a long term follow-up is required, since their orbital periods may reach several centuries. Created in 1981 within the Société Astronomique de France (SAF) with the support of the late Paul Muller (1910-2000), the Commission des Etoiles Doubles provides the framework for the necessary collaboration between professional and amateur astronomers, through generations. The late Dr. Paul Baize (1901-1995) was a model for its members. Several professional astronomers became scientific advisors of the Commission and have guided many works made by amateurs.
Education and public outreach initiatives from the National Aeronautics and Space Administration
Authors: Daou Doris
Published: June 2011

From the dawn of consciousness, humans have looked up and wondered about what the universe holds. It is that sense of wonder and thirst for knowledge that astronomy has helped fuel. In this paper we look at how education and public outreach has been a major element in preparing the next generation of astronomers and in sharing with the public the excitement of discoveries we make when we explore the Universe. The National Aeronautics and Space Administration (NASA) has a clear set of goals and objectives related to education and public outreach. These goals follow directly from NASA's mission “to inspire the next generation of explorers”. Making progress towards achieving these goals has become an important part of the broad justification for public support of space science. Here we will describe a number of education and public outreach initiatives that are examples of the plethora of NASA funded programs and resources.
Extraverts Have Larger Social Network Layers
Authors: Pollet Thomas V. , Roberts Sam G. B. , Dunbar Robin I. M.
Published: June 2011

Previous studies showed that extraversion influences social network size. However, it is unclear how extraversion affects the size of different layers of the network, and how extraversion relates to the emotional intensity of social relationships. We examined the relationships between extraversion, network size, and emotional closeness for 117 individuals. The results demonstrated that extraverts had larger networks at every layer (support clique, sympathy group, outer layer). The results were robust and were not attributable to potential confounds such as sex, though they were modest in size (raw correlations between extraversion and size of network layer, .20 < r < .23). However, extraverts were not emotionally closer to individuals in their network, even after controlling for network size. These results highlight the importance of considering not just social network size in relation to personality, but also the quality of relationships with network members.
SK2 Channels Are Neuroprotective for Ischemia-Induced Neuronal Cell Death
Authors: Allen Duane , Nakayama Shin , Kuroiwa Masayuki , Nakano Takaaki , Palmateer Julie , Kosaka Yasuharu , Ballesteros Carmen , Watanabe Masahiko , Bond Chris T , Luján Rafael , Maylie James , Adelman John P , Herson Paco S
Published: June 2011

In mouse hippocampal CA1 pyramidal neurons, the activity of synaptic small-conductance Ca2+-activated K+ channels type 2 (SK2 channels) provides a negative feedback on N-methyl-d-aspartate receptors (NMDARs), reestablishing Mg2+ block that reduces Ca2+ influx. The well-established role of NMDARs in ischemia-induced excitotoxicity led us to test the neuroprotective effect of modulating SK2 channel activity following cerebral ischemia induced by cardiac arrest and cardiopulmonary resuscitation (CA/CPR). Administration of the SK channel positive modulator, 1-ethyl-benzimidazolinone (1-EBIO), significantly reduced CA1 neuron cell death and improved CA/CPR-induced cognitive outcome. Electrophysiological recordings showed that CA/CPR-induced ischemia caused delayed and sustained reduction of synaptic SK channel activity, and immunoelectron microscopy showed that this is associated with internalization of synaptic SK2 channels, which was prevented by 1-EBIO treatment. These results suggest that increasing SK2 channel activity, or preventing ischemia-induced loss of synaptic SK2 channels, are promising and novel approaches to neuroprotection following cerebral ischemia.
Effect of Manganese Chloride on the Neurochemical Profile of the Rat Hypothalamus
Authors: Just Nathalie , Cudalbu Cristina , Lei Hongxia , Gruetter Rolf
Published: June 2011

Manganese (Mn2+)-enhanced magnetic resonance imaging studies of the neuronal pathways of the hypothalamus showed that information about the regulation of food intake and energy balance circulate through specific hypothalamic nuclei. The dehydration-induced anorexia (DIA) model demonstrated to be appropriate for studying the hypothalamus with Mn2+-enhanced magnetic resonance imaging. Manganese is involved in the normal functioning of a variety of physiological processes and is associated with enzymes contributing to neurotransmitter synthesis and metabolism. It also induces psychiatric and motor disturbances. The molecular mechanisms by which Mn2+ produces alterations of the hypothalamic physiological processes are not well understood. 1H-magnetic resonance spectroscopy measurements of the rodent hypothalamus are challenging due to the distant location of the hypothalamus resulting in limited measurement sensitivity. The present study proposed to investigate the effects of Mn2+ on the neurochemical profile of the hypothalamus in normal, DIA, and overnight fasted female rats at 14.1 T. Results provide evidence that γ-aminobutyric acid has an essential role in the maintenance of energy homeostasis in the hypothalamus but is not condition specific. On the contrary, glutamine, glutamate, and taurine appear to respond more accurately to Mn2+ exposure. An increase in glutamine levels could also be a characteristic response of the hypothalamus to DIA.
Cascading dynamics in complex quantum networks
Authors: Huang Liang , Lai Ying-Cheng
Published: June 2011

Recently, small-scale quantum communication has been realized by transporting entangled photons, rendering potentially feasible quantum networks on large scales. We propose a class of quantum networks comprising quantum repeaters for long-distance information transport and local networks of fibers and switches. As the transmitting capability is limited by the node bandwidth, photon loss can occur through the dynamical process of cascading when the network is under external perturbations. We obtain results that can be used to guide quantum network design to minimize the photon loss.
Coordinated scheduling of electricity and natural gas infrastructures with a transient model for natural gas flow
Authors: Liu Cong , Shahidehpour Mohammad , Wang Jianhui
Published: June 2011

This paper focuses on transient characteristics of natural gas flow in the coordinated scheduling of security-constrained electricity and natural gas infrastructures. The paper takes into account the slow transient process in the natural gas transmission systems. Considering their transient characteristics, natural gas transmission systems are modeled as a set of partial differential equations (PDEs) and algebraic equations. An implicit finite difference method is applied to approximate PDEs by difference equations. The coordinated scheduling of electricity and natural gas systems is described as a bi-level programming formulation from the independent system operator’s viewpoint. The objective of the upper-level problem is to minimize the operating cost of electric power systems while the natural gas scheduling optimization problem is nested within the lower-level problem. Numerical examples are presented to verify the effectiveness of the proposed solution and to compare the solutions for steady-state and transient models of natural gas transmission systems.
Femtosecond time-resolved photoelectron spectroscopy with a vacuum-ultraviolet photon source based on laser high-order harmonic generation
Authors: Wernet Philippe , Gaudin Jérôme , Godehusen Kai , Schwarzkopf Olaf , Eberhardt Wolfgang
Published: June 2011

A laser-based tabletop approach to femtosecond time-resolved photoelectron spectroscopy with photons in the vacuum-ultraviolet (VUV) energy range is described. The femtosecond VUV pulses are produced by high-order harmonic generation (HHG) of an amplified femtosecond Ti:sapphire laser system. Two generations of the same setup and results from photoelectron spectroscopy in the gas phase are discussed. In both generations, a toroidal grating monochromator was used to select one harmonic in the photon energy range of 20–30 eV. The first generation of the setup was used to perform photoelectron spectroscopy in the gas phase to determine the bandwidth of the source. We find that our HHG source has a bandwidth of 140 ± 40 meV. The second and current generation is optimized for femtosecond pump-probe photoelectron spectroscopy with high flux and a small spot size at the sample of the femtosecond probe pulses. The VUV radiation is focused into the interaction region with a toroidal mirror to a spot smaller than 100 × 100 μm2 and the flux amounts to 1010 photons/s at the sample at a repetition rate of 1 kHz. The duration of the monochromatized VUV pulses is determined to be 120 fs resulting in an overall pump-probe time resolution of 135 ± 5 fs. We show how this setup can be used to map the transient valence electronic structure in molecular dissociation.
Interfacial thin films rupture and self-similarity
Authors: Ward Margaret H.
Published: June 2011

Two superposed thin layers of fluids are prone to interfacial instabilities due to London-van der Waals forces. Evolution equations for the film thicknesses are derived using lubrication theory. Using the intrinsic scales, for a single layer, results in a system with parametric dependence of four ratios of the two layers: surface tension, Hamaker constant, viscosity, and film thickness. In contrast to the single layer case, the bilayer system has two unstable eigenmodes: squeezing and bending. For some particular parameter regimes, the system exhibits the avoided crossing behavior, where the two eigenmodes are interchanged. Based on numerical analysis, the system evolves into four different rupture states: basal layer rupture, upper layer rupture, double layer rupture, and mixed layer rupture. The ratio of Hamaker constants and the relative film thickness of the two layers control the system dynamics. Remarkably, the line of avoided crossing demarks the transition region of mode mixing and energy transfer, affecting the scaling of the dynamical regime map consequentially. Asymptotic and numerical analyses are used to examine the self-similar ruptures and to extract the power law scalings for both the basal layer rupture and the upper layer rupture. The scaling laws for the basal layer rupture are the same as those of the single layer on top of a substrate. The scaling laws for the upper layer rupture are different: the lateral length scale decreases according to (tr-t)1/3 and the film thickness decreases according to (tr-t)1/6.
Nuclear magnetic resonance study of the superprotonic conduction in LiH2PO4
Authors: Kweon Jin Jung , Won Lee Kyu , Eui Lee Cheol , Lee Kwang-Sei
Published: June 2011

Superprotonic conduction in the LiH2PO4 system has been studied by means of high-resolution nuclear magnetic resonance measurements, which enabled us to distinguish dynamics of the two different hydrogen bonds in the structure. The protonic motion, primarily associated with the longer hydrogen bond, rather than the Li ionic motion, was revealed to dictate the extraordinarily high electrical conductivity of the system.
The multilevel impact of transformational leadership on teacher commitment: Cognitive and motivational pathways
Authors: Dumay Xavier , Galand Benoît
Published: June 2011

A growing body of research indicates that transformational leadership affects teachers’ commitment to their school. The present study aims to investigate the processes explaining this effect at the organisational level. Using a sample of 660 teachers within 50 primary French‐speaking Belgian schools, the authors test a model hypothesising that the impact of the school principal's transformational leadership (as an organisational‐level construct) on teacher commitment to school is mediated by school culture strength (cognitive pathway) and teacher collective efficacy beliefs (motivational pathway). Results of multilevel analyses largely support the theoretical model, but show that schools have a limited impact on teacher commitment.
CAMPAIGN: an open-source library of GPU-accelerated data clustering algorithms
Authors: Kohlhoff Kai J. , Sosnick Marc H. , Hsu William T. , Pande Vijay S. , Altman Russ B.
Published: June 2011

Motivation: Data clustering techniques are an essential component of a good data analysis toolbox. Many current bioinformatics applications are inherently compute-intense and work with very large datasets. Sequential algorithms are inadequate for providing the necessary performance. For this reason, we have created Clustering Algorithms for Massively Parallel Architectures, Including GPU Nodes (CAMPAIGN), a central resource for data clustering algorithms and tools that are implemented specifically for execution on massively parallel processing architectures.

Results:  CAMPAIGN is a library of data clustering algorithms and tools, written in ‘C for CUDA’ for Nvidia GPUs. The library provides up to two orders of magnitude speed-up over respective CPU-based clustering algorithms and is intended as an open-source resource.

New modules from the community will be accepted into the library and the layout of it is such that it can easily be extended to promising future platforms such as OpenCL.

Availability: Releases of the CAMPAIGN library are freely available for download under the LGPL from https://simtk.org/home/campaign. Source code can also be obtained through anonymous subversion access as described on https://simtk.org/scm/?group_id=453.

Contact:  kjk33@cantab.net
Topology‐based Visualization of Transformation Pathways in Complex Chemical Systems
Authors: Beketayev K. , Weber G.H. , Haranczyk M. , Bremer P.‐T. , Hlawitschka M. , Hamann B.
Published: June 2011

Studying transformation in a chemical system by considering its energy as a function of coordinates of the system's components provides insight and changes our understanding of this process. Currently, a lack of effective visualization techniques for high‐dimensional energy functions limits chemists to plot energy with respect to one or two coordinates at a time. In some complex systems, developing a comprehensive understanding requires new visualization techniques that show relationships between all coordinates at the same time. We propose a new visualization technique that combines concepts from topological analysis, multi‐dimensional scaling, and graph layout to enable the analysis of energy functions for a wide range of molecular structures. We demonstrate our technique by studying the energy function of a dimer of formic and acetic acids and a LTA zeolite structure, in which we consider diffusion of methane.
Interactive Visual Analysis of Temporal Cluster Structures
Authors: Turkay C. , Parulek J. , Reuter N. , Hauser H.
Published: June 2011

Cluster analysis is a useful method which reveals underlying structures and relations of items after grouping them into clusters. In the case of temporal data, clusters are defined over time intervals where they usually exhibit structural changes. Conventional cluster analysis does not provide sufficient methods to analyze these structural changes, which are, however, crucial in the interpretation and evaluation of temporal clusters. In this paper, we present two novel and interactive visualization techniques that enable users to explore and interpret the structural changes of temporal clusters. We introduce the temporal cluster view, which visualizes the structural quality of a number of temporal clusters, and temporal signatures, which represents the structure of clusters over time. We discuss how these views are utilized to understand the temporal evolution of clusters. We evaluate the proposed techniques in the cluster analysis of mixed lipid bilayers.
Lagrangian Coherent Structures with Guaranteed Material Separation
Authors: Germer T. , Otto M. , Peikert R. , Theisel H.
Published: June 2011

Given an unsteady flow field, one common way to compute Lagrangian Coherent Structures (LCS) is to extract extremal structures of the Finite Time Lyapunov Exponent (FTLE). Experience has shown that the resulting structures are often close to material structures (i.e., material lines or material surfaces). Moreover, it has been proven that for an integration time converging to infinity, they converge to exact material structures. However, due to the finite integration time in FTLE, they are generally not exact material structures.

In this paper we introduce a modification of the FTLE method which is guaranteed to produce separating material structures as features of a scalar field. We achieve this by incorporating the complete available integration time both in forward and backward direction, and by choosing an appropriate definition for separating structures. We apply our method to two test data sets and show the differences to classical FTLE.
Energy‐scale Aware Feature Extraction for Flow Visualization
Authors: Pobitzer A. , Tutkun M. , Andreassen Ø. , Fuchs R. , Peikert R. , Hauser H.
Published: June 2011

In the visualization of flow simulation data, feature detectors often tend to result in overly rich response, making some sort of filtering or simplification necessary to convey meaningful images. In this paper we present an approach that builds upon a decomposition of the flow field according to dynamical importance of different scales of motion energy. Focusing on the high‐energy scales leads to a reduction of the flow field while retaining the underlying physical process. The presented method acknowledges the intrinsic structures of the flow according to its energy and therefore allows to focus on the energetically most interesting aspects of the flow. Our analysis shows that this approach can be used for methods based on both local feature extraction and particle integration and we provide a discussion of the error caused by the approximation. Finally, we illustrate the use of the proposed approach for both a local and a global feature detector and in the context of numerical flow simulations.
Visual Reconstructability as a Quality Metric for Flow Visualization
Authors: Jänicke Heike , Weidner Thomas , Chung David , Laramee Robert S. , Townsend Peter , Chen Min
Published: June 2011

We present a novel approach for the evaluation of 2D flow visualizations based on the visual reconstructability of the input vector fields. According to this metric, a visualization has high quality if the underlying data can be reliably reconstructed from the image. This approach provides visualization creators with a cost‐effective means to assess the quality of visualization results objectively. We present a vision‐based reconstruction system for the three most commonly‐used visual representations of vector fields, namely streamlines, arrow glyphs, and line integral convolution. To demonstrate the use of visual reconstructability as a quality metric, we consider a selection of vector fields obtained from numerical simulations, containing typical flow features. We apply the three types of visualization to each dataset, and compare the visualization results based on their visual reconstructability of the original vector field.
Depth of Field Effects for Interactive Direct Volume Rendering
Authors: Schott Mathias , Pascal Grosset A.V. , Martin Tobias , Pegoraro Vincent , Smith Sean T. , Hansen Charles D.
Published: June 2011

In this paper, a method for interactive direct volume rendering is proposed for computing depth of field effects, which previously were shown to aid observers in depth and size perception of synthetically generated images. The presented technique extends those benefits to volume rendering visualizations of 3D scalar fields from CT/MRI scanners or numerical simulations. It is based on incremental filtering and as such does not depend on any pre‐computation, thus allowing interactive explorations of volumetric data sets via on‐the‐fly editing of the shading model parameters or (multi‐dimensional) transfer functions.
Fast Extraction of High‐quality Crease Surfaces for Visual Analysis
Authors: Barakat S. , Andrysco N. , Tricoche X.
Published: June 2011

We present a novel algorithm for the efficient extraction and visualization of high‐quality ridge and valley surfaces from numerical datasets. Despite their rapidly increasing popularity in visualization, these so‐called crease surfaces remain challenging to compute owing to their strongly nonlinear and non‐orientable nature, and their complex boundaries. In this context, existing meshing techniques require an extremely dense sampling that is computationally prohibitive. Our proposed solution intertwines sampling and meshing steps to yield an accurate approximation of the underlying surfaces while ensuring the geometric quality of the resulting mesh. Using the computation power of the GPU, we propose a fast, parallel method for sampling. Additionally, we present a new front propagation meshing strategy that leverages CPU multiprocessing. Results are shown for synthetic, medical and fluid dynamics datasets.
Temporal Visualization of Boundary‐based Geo‐information Using Radial Projection
Authors: Drocourt Y. , Borgo R. , Scharrer K. , Murray T. , Bevan S. I. , Chen M.
Published: June 2011

This work is concerned with a design study by an interdisciplinary team on visualizing a 10‐year record of seasonal and inter‐annual changes in frontal position (advance/retreat) of nearly 200 marine terminating glaciers in Greenland. Whilst the spatiotemporal nature of the raw data presents a challenge to develop a compact and intuitive visual design, the focus on coastal boundaries provides an opportunity for dimensional reduction. In this paper, we report the user‐centered design process carried out by the team, and present several visual encoding schemes that have met the requirements including compactness, intuitiveness, and ability to depict temporal changes and spatial relations. In particular, we designed a family of radial visualization, where radial lines correspond to different coastal locations, and nested rings represent the evolution of the temporal dimension from inner to outer circles. We developed an algorithm for mapping glacier terminus positions from Cartesian coordinates to angular coordinates. Instead of a naive uniform mapping, the algorithm maintains consistent spatial perception of the visually‐sensitive geographical references between their Cartesian and angular coordinates, and distributes other termini positions between primary locations based on coastal distance. This work has provided a useful solution to address the problem of inaccuracy in change evaluation based on pixel‐based visualization [BPC*10].
Anatomy‐Guided Multi‐Level Exploration of Blood Flow in Cerebral Aneurysms
Authors: Neugebauer Mathias , Janiga Gabor , Beuing Oliver , Skalej Martin , Preim Bernhard
Published: June 2011

For cerebral aneurysms, the ostium, the area of inflow, is an important anatomic landmark, since it separates the pathological vessel deformation from the healthy parent vessel. A better understanding of the inflow characteristics, the flow inside the aneurysm and the overall change of pre‐ and post‐aneurysm flow in the parent vessel provide insights for medical research and the development of new risk‐reduced treatment options. We present an approach for a qualitative, visual flow exploration that incorporates the ostium and derived anatomical landmarks. It is divided into three scopes: a global scope for exploration of the in‐ and outflow, an ostium scope that provides characteristics of the flow profile close to the ostium and a local scope for a detailed exploration of the flow in the parent vessel and the aneurysm. The approach was applied to five representative datasets, including measured and simulated blood flow. Informal interviews with two board‐certified radiologists confirmed the usefulness of the provided exploration tools and delivered input for the integration of the ostium‐based flow analysis into the overall exploration workflow.
Use of a blocking ELISA for antibodies to equine influenza virus as a test to distinguish between naturally infected and vaccinated horses: proof of concept studies
Authors: Kirkland PD , Delbridge G
Published: June 2011

An important consideration in the selection of a vaccine during the Australian equine influenza (EI) outbreak in 2007 was the ability to differentiate between infected and vaccinated animals (DIVA). A blocking enzyme‐linked immunosorbent assay (bELISA) targeted for the nucleoprotein of influenza A viruses was developed to differentiate between naturally infected horses and horses vaccinated with the ProteqFlu® vaccine, which only induces a response to viral haemagglutinin. This bELISA assay met the DIVA requirements and was used extensively during the EI control and eradication programs and ‘proof of freedom’ testing.