bluuebunny/crossref_metadata_2025 huggingface dataset:
The One Year Incidence of Postoperative Myocardial Infarction in an Orthopedic Population
Authors: Urban M. K. , Jules-Elysee K. , Loughlin C. , Kelsey W. , Flynn E.
Published: December 2007

The diagnosis of a postoperative myocardial infarction (PMI) is important in the orthopedic population because these events can be associated with significant cardiac morbidity. Plasma troponin I (cTnI) analysis has markedly increased our ability to detect myocardial damage. Using cTnI analysis for evidence of a PMI, we prospectively assessed all of our patients for (1) the 1-year incidence of PMI, (2) the clinical consequences of a PMI in relation to the level of the cTnI release, and (3) 6-month follow-up for cardiac complications. During a 12-month period, patients at risk for perioperative myocardial ischemia were assessed for a PMI by serum cTnI levels and daily serial ECGs. Patients with cTnI levels above the reference level (≥0.4 ng/ml) were also assessed for new cardiac regional wall motion abnormalities with an echocardiogram and 6-month postdischarge adverse cardiac events. Of the 758 patients who were assessed for a PMI, 49 patients had detectable cTnI levels (≥0.4 ng/ml); the incidence of a PMI was 0.6% of all surgical cases and 6.5% of those patients were at risk for a cardiac event. A PMI was more common after hip arthroplasty than other orthopedic procedures. Twenty-three patients had a cTnI level >3.0 ng/ml, and 74% these patients (17/23) had anginal symptoms and/or ischemic ECG changes. Nine of these patients (9/23) had new postoperative echocardiographic changes, five (5/23) required emergency transfer to a cardiac care unit, and 10 (10/23) had postoperative cardiac complications. In contrast, 15 patients with levels of cTnI <3.0 ng/ml and without ischemic ECG changes and/or anginal symptoms had no postoperative cardiac complications. Fourteen patients (14/47) had cardiac complications 6 months after discharge, including four cardiac deaths, one fatal stroke, and four patients with unstable anginal episodes that required a change in medical management, and six patients required coronary revascularization. Orthopedic surgical patients with cTnI level <3 ng/ml and without symptoms or ECG changes suggestive of myocardial ischemia (15/49) may have different risks than those with higher-level cTn1.
Acidolysis of Tripalmitin with Oleic Acid Catalyzed by a Newly Isolated Thermostable Lipase
Authors: Guncheva M. , Zhiryakova D. , Radchenkova N. , Kambourova M.
Published: December 2007

The catalytic efficiency of a lipase from Bacillus stearothermophilus MC7 (lipase MC7) was evaluated in acidolysis of tripalmitin with oleic acid to yield dioleoylpalmitoylglycerol, a structured triglyceride used in health food. The immobilized enzyme exhibits good operational thermostability with a half‐life of 50 days at 60 °C in a solvent‐free system. The degree of conversion exceeded 50% after 48 h. The side reaction of hydrolysis was suppressed. However, the monosubstituted product was prevalent in the product mixture. Tested in a broad range of solvents, lipase MC7 showed tolerance towards medium polarity.
High throughput molecular diagnostics in bladder cancer — on the brink of clinical utility
Authors: Zieger Karsten
Published: December 2007

An enormous body of high‐throughput genome‐wide data, in particular gene expression data, has been gathered from roughly all human cancer forms in the past 10years. This has widely increased our understanding of the cancer disease and its molecular changes and pathways, with a large contribution from studies of cancer cell lines and functional genomics. In the last three years, the focus has been moved to clinical outcome parameters as recurrence, progression, metastasis and treatment response. The huge variability of molecular changes and poor availability of samples have hampered progress in the field of epithelial cancer (carcinoma). However, independent validation of molecular profiles across high‐throughput platforms, methods, laboratories and cancer populations has recently been successfully performed for several carcinomas, including bladder cancer. Application of advanced bioinformatics to identify interrelated pathways has revealed common signatures predictive of molecular subgroups, improving histopathological diagnosis, and ultimately outcome prediction. With breast cancer leading the field, colorectal, bladder and renal cell carcinomas well on their way, and many others soon to join, the era of clinical applications of high‐throughput molecular methods in cancer lies closely ahead. This review illustrates in detail the perspectives for the management of bladder cancer.
Electoral Accountability and the Variety of Democratic Regimes
Authors: HELLWIG TIMOTHY , SAMUELS DAVID
Published: December 2007

Do voters reward or punish incumbents for retrospective performance similarly in different democratic regimes? Despite debates on the merits of different regimes, little research has investigated the implications of constitutional design on voters' ability to hold politicians to account. This article shows that regime type determines the way and extent to which elections enable voters to reward or sanction incumbents. These regime effects are separate from and conceptually prior to factors previously identified in the literature on comparative economic voting. Analysis of elections from seventy-five countries reveals that, all else equal, voters have greater potential to hold incumbents to accounts under the separation of powers than under parliamentarism. Moreover, variables particular to separation of powers systems – the electoral cycle in pure presidential systems and instances of cohabitation in semi-presidential systems – affect the relative impact of the attribution of responsibility. The results contribute to ongoing debates about the relative advantages of different constitutional formats for democratic performance.
Getting Out the Vote: Party Mobilization in a Comparative Perspective
Authors: KARP JEFFREY A. , BANDUCCI SUSAN A. , BOWLER SHAUN
Published: December 2007

A long tradition within political science examines the impact of party canvassing on voter participation. Very little of this work, however, is comparative in scope. This essay examines how system-level characteristics shape the nature and impact of party canvassing and how voters respond to those efforts. Parties are found to target the same types of potential voters everywhere – those who are likely to participate. However, one important difference is that overall levels of party contact are far greater in candidate-based systems than in proportional representation (PR) systems. Party mobilization, therefore, cannot explain the higher rates of turnout observed in PR systems.
The Mechanismic Worldview: Thinking Inside the Box
Authors: GERRING JOHN
Published: December 2007

A widespread turn towards mechanism-centred explanations can be viewed across the social sciences in recent decades. This article clarifies what it might mean in practical terms to adopt a mechanismic view of causation. This simple task of definition turns out to be considerably more difficult than it might at first appear. The body of the article elucidates a series of tensions and conflicts within this ambient concept, looking closely at how influential authors have employed this ubiquitous term. It is discovered that ‘mechanism’ has at least nine distinct meanings as the term is used within contemporary social science: (1) the pathway or process by which an effect is produced; (2) an unobservable causal factor; (3) an easy-to-observe causal factor; (4) a context-dependent (bounded) explanation; (5) a universal (or at least highly general) explanation; (6) an explanation that presumes highly contingent phenomena; (7) an explanation built on phenomena that exhibit lawlike regularities; (8) a distinct technique of analysis (based on qualitative, case study, or process-tracing evidence); or (9) a micro-level explanation for a causal phenomenon. Some of these meanings may be combined into coherent definitions; others are obviously contradictory. It is argued, however, that only the first meaning is consistent with all contemporary usages and with contemporary practices within the social sciences; this is therefore proposed as a minimal (core) definition of the concept. The other meanings are regarded as arguments surrounding the core concept.
Exact analytic solutions for nonlinear waves in cold plasmas
Authors: ROWLANDS G. , BRODIN G. , STENFLO L.
Published: December 2007

Large amplitude plasma oscillations are studied in a cold electron plasma. Using Lagrangian variables, a new class of exact analytical solutions is found. It turns out that the electric field amplitude is limited either by wave breaking or by the condition that the electron density always has to stay positive. The range of possible amplitudes is determined analytically.
Teaching third languages: Findings, trends and challenges
Authors: Jessner Ulrike
Published: December 2007

The last decade has witnessed a rapid increase in interest in multilingualism. Whereas a number of scholars in language acquisition research still base their work on the monolingual native speaker norm, others have developed more realistic viewpoints. This article provides an overview of international research on third language learning and teaching, including examples mainly from a European background. It describes sociolinguistic, psycholinguistic and educational aspects of multilingual teaching and emphasizes current research trends in this fairly young area of language teaching. The challenging ways which have been suggested to achieve multilingualism for all necessarily have to address learners, teachers, educators and policy makers. It will be argued that multilingual education can only be successful if language teaching in general is restructured and oriented towards multilingual norms.
Optimal Interceptions on Two-Dimensional Grids with Obstacles
Authors: Chang Ki Yin , Jan Gene Eu , Su Chien-Min , Parberry Ian
Published: December 2007

This article presents efficient and practical methods for path planning of optimal interceptions on two-dimensional grids with obstacles, such as raster charts or non-distorted digital maps. The proposed methods search for optimal paths from sources to multiple moving-targets by a novel higher geometry wave propagation scheme in the grids, instead of the traditional vector scheme in the graphs. By introducing a time-matching scheme, the optimal interception paths from sources to all the moving-targets are obtained among the combinations with linear time and space complexities. Two optimal path planning methods for multiple one-to-one interceptions, the MIN-MAX and MIN-AVG, are applied to emulate the real routing.
A Study Of Direct Severe Space Weather Effects On GPS Ionospheric Delay
Authors: Filjar Renato
Published: December 2007

Severe space weather conditions affect the performance of numerous modern technical systems, causing problems not only for national and global economies, but for everyday life as well. Satellite navigation systems are particularly vulnerable, despite the fact that systematic monitoring of space weather in general is still performed on a global scale. Space weather effect correction models applied within the standard satellite positioning service are not capable of tackling the effects of severe space weather conditions and local ionospheric characteristics. Severe space weather effects on the GPS ionospheric delay are intensely studied in order to provide advanced models of the space weather effects on GPS positioning performance.

Here one study of severe space weather conditions and its consequences on the GPS ionospheric delay in Croatia is presented. The study takes advantage of the availability of the space weather indices and the GPS pseudorange measurements (taken at the reference site at Osijek, Croatia) related to a major severe space weather event lasting from early October 2003 to late November 2003. This paper presents the reconstruction of the severe space weather conditions and the development of ionospheric disturbances. Based on these reconstructions, the dynamics of the GPS ionospheric delay has been derived. The comparison of actual (measured) and modelled (according to standard GPS model) GPS ionospheric delay has been performed, with the aims of identifying actual behaviour of GPS ionospheric delay and examining the ability of standard (Klobuchar) GPS model to describe the GPS ionospheric delay in severe space weather conditions. Two interesting experimental models derived from the data analysis are presented, addressing the direct relations between the GPS ionospheric delay and the parameters of space weather activity (sunspot number and solar flux), as observed at the reference station Osijek, Croatia.

The paper concludes with the plans for further research activities related to the regional GPS ionospheric delay model development for south-eastern Europe.
Particle Swarm Guidance System for Autonomous Unmanned Aerial Vehicles in an Air Defence Role
Authors: Banks Alec , Vincent Jonathan , Phalp Keith
Published: December 2007

This work investigates the utilisation of Particle Swarm Optimisation (PSO) for the non-deterministic navigation of Unmanned Aerial Vehicles (UAVs), allowing them to work cooperatively toward the goal of protecting a wide area against airborne attack. To negate the PSO's inherent weakness in dynamic environments, a neighbourhood scheme is proposed that not only enables the efficient interception of targets several times faster than the UAVs but also facilitates the maintenance of effective airspace coverage. Empirical results suggest that these techniques may indeed be of use in autonomous navigation systems for UAVs in air defence roles.
The First Escort Tractor Voith Tug with a Bulbous Bow: Analysis and Consequences
Authors: Baniela Santiago Iglesias , Díaz Álvaro Platero
Published: December 2007

On February, 15th 2005, Gondán S.A. shipyard in the north-west of Spain handed over the escort tractor Voith tug “VELOX” to the Norwegian shipowner Østensjø Rederi AS, the first of this type in the world to incorporate a bulbous bow. After generally making a reference to the benefits obtained by the incorporation of a bulbous bow regarding the reduction of the ship's resistance, we specifically analyse the consequences derived from the incorporation of this appendage in an escort tractor Voith tug concerning its real operating conditions when carrying out escort tasks, especially when using the indirect towing method.
Heavy Weather in European Short Sea Shipping: Its Influence on Selected Routes
Authors: de Osés F Xavier Martínez , Castells Marcel.la
Published: December 2007

According to the mid-term review of the EU White Paper on Transport, short sea shipping is expected to grow at a rate of 59% in metric tonnes, from 2000 to 2020. If we consider that the overall expected growth in freight exchanges is of some 50%, sea transport is one of the most feasible ways to reduce traffic congestion on European roads. High speed vessels are a possible way to compete with road transport on certain routes; however, these ships are highly affected by heavy weather. This paper analyses the weather influence on several short sea shipping routes to be served by fast ships.
Autonomous Ship Collision Avoidance Navigation Concepts, Technologies and Techniques
Authors: Statheros Thomas , Howells Gareth , Maier Klaus McDonald
Published: December 2007

This study provides both a spherical understanding about autonomous ship navigation for collision avoidance (CA) and a theoretical background of the reviewed work. Additionally, the human cognitive abilities and the collision avoidance regulations (COLREGs) for ship navigation are examined together with water based collision avoidance algorithms. The requirements for autonomous ship navigation are addressed in conjunction with the factors influencing ship collision avoidance. Humans are able to appreciate these factors and also perform ship navigation at a satisfactory level, but their critical decisions are highly subjective and can lead to error and potentially, to ship collision. The research for autonomous ship navigation may be grouped into the classical and soft computing based categories. Classical techniques are based on mathematical models and algorithms while soft-computing techniques are based on Artificial Intelligence (AI). The areas of AI for autonomous ship collision avoidance are examined in this paper are evolutionary algorithms, fuzzy logic, expert systems, and neural networks (NN), as well as a combination of them (hybrid system).
UWB Positioning Systsem Design: Selection of Modulation and Multiple Access Schemes
Authors: Yu Hui , Aguado Enrique , Brodin Gary , Cooper John , Walsh David , Strangeways Hal
Published: December 2007

In densely-populated cities or indoor environments, limited visibility to satellites and severe multipath effects significantly affect the accuracy and reliability of satellite-based positioning systems. To meet the needs of “seamless navigation” in these challenging environments an advanced terrestrial positioning system is under development. This system is based upon Ultra-Wideband (UWB) technology, which is a promising candidate for this application due to good time domain resolution and immunity to multipath. This paper presents a detailed analysis of two key aspects of the UWB signal design that will allow it to be used as the basis of such a high performance positioning system: the modulation scheme and the multiple access technique. These two aspects are evaluated in terms of spectral efficiency and synchronisation performance over multipath channels. Thus this paper identifies optimal modulation and multiple access techniques for a long range, high performance terrestrial positioning system using UWB.
Sexual dimorphism in campylobacteriosis
Authors: STRACHAN N. J. C. , WATSON R. O. , NOVIK V. , HOFREUTER D. , OGDEN I. D. , GALÁN J. E.
Published: December 2007

Sexual dimorphism in infectious diseases whereby disease incidence is more prevalent in one gender has been reported repeatedly in the scientific literature. Both behavioural and physiological differences have been suggested as a cause of this gender bias but there is a paucity of data to support either of these viewpoints. Here it is hypothesized that for campylobacteriosis physiological factors play an important role in the higher incidence in males. We demonstrate in the human population (from several countries in three continents) that this bias exists in young children (<1 year) where behavioural differences between genders are likely to be minimal. Further we demonstrate this difference in an animal model where both infection rates and shedding rates of the organism are greater in male mice.
Three Counter-Examples on Semi-Graphoids
Authors: HEMMECKE RAYMOND , MORTON JASON , SHIU ANNE , STURMFELS BERND , WIENAND OLIVER
Published: December 2007

Semi-graphoids are combinatorial structures that arise in statistical learning theory. They are equivalent to convex rank tests and to polyhedral fans that coarsen the reflection arrangement of the symmetric group Sn. In this paper we resolve two problems on semi-graphoids posed in Studený's book (2005), and we answer a related question of Postnikov, Reiner and Williams on generalized permutohedra. We also study the semigroup and the toric ideal associated with semi-graphoids.
Constrained Ramsey Numbers
Authors: LOH PO-SHEN , SUDAKOV BENNY
Published: December 2007

For two graphs S and T, the constrained Ramsey number f(S, T) is the minimum n such that every edge colouring of the complete graph on n vertices (with any number of colours) has a monochromatic subgraph isomorphic to S or a rainbow subgraph isomorphic to T. Here, a subgraph is said to be rainbow if all of its edges have different colours. It is an immediate consequence of the Erdős–Rado Canonical Ramsey Theorem that f(S, T) exists if and only if S is a star or T is acyclic. Much work has been done to determine the rate of growth of f(S, T) for various types of parameters. When S and T are both trees having s and t edges respectively, Jamison, Jiang and Ling showed that f(S, T) ≤ O(st2) and conjectured that it is always at most O(st). They also mentioned that one of the most interesting open special cases is when T is a path. In this paper, we study this case and show that f(S, Pt) = O(st log t), which differs only by a logarithmic factor from the conjecture. This substantially improves the previous bounds for most values of s and t.
Robert Mylne, Thomas Telford and the architecture of improvement: the planned villages of the British Fisheries Society, 1786–1817
Authors: MAUDLIN DANIEL
Published: December 2007

This article examines the architecture and design of the pioneering planned fishing villages established by the British Fisheries Society across the Highlands of Scotland in the late eighteenth and early nineteenth centuries. The Society established a utilitarian planning model which fundamentally influenced the subsequent planned village boom that remains so evident in the historic landscape of the Scottish Highlands today. The British Fisheries Society also made a significant contribution to urban history with Thomas Telford's innovative plan for its last development of Pulteneytown. Pulteneytown remains the most complete example of Telford's work as a town planner.
‘Shauri ya Sera Kali’: the colonial regime of urban housing in Kenya to 1939
Authors: HAY ALISON , HARRIS RICHARD
Published: December 2007

The social relationships of housing tenure shape urban life. One of the most peculiar tenure regimes emerged in the towns of East and Central Africa during the colonial period. In accordance with the colonial policy of trusteeship, employers and municipalities were together responsible for housing all permanently employed Africans, who constituted the majority in most urban centres. Contemporaries noted that employers and municipalities commonly failed to do their job, a judgement that historians have endorsed. In fact, their contribution varied greatly from place to place and, though generally insufficient, was still substantial. This paternalistic tenure regime created dependency and open-ended commitments that could not be met.
Healthy whole-grain choices for children and parents: a multi-component school-based pilot intervention
Authors: Burgess-Champoux Teri L , Chan Hing Wan , Rosen Renee , Marquart Len , Reicks Marla
Published: December 2007

Objective

The aim of the present study was to pilot-test a school-based intervention designed to increase consumption of whole grains by 4th and 5th grade children.

Design

This multi-component school-based pilot intervention utilised a quasi-experimental study design (intervention and comparison schools) that consisted of a five-lesson classroom curriculum based on Social Cognitive Theory, school cafeteria menu modifications to increase the availability of whole-grain foods and family-oriented activities. Meal observations of children estimated intake of whole grains at lunch. Children and parents completed questionnaires to assess changes in knowledge, availability, self-efficacy, usual food choice and role modelling.

Setting/sample

Parent/child pairs from two schools in the Minneapolis metropolitan area; 67 in the intervention and 83 in the comparison school.

Results

Whole-grain consumption at the lunch meal increased by 1 serving (P< 0·0001) and refined-grain consumption decreased by 1 serving for children in the intervention school compared with the comparison school post-intervention (P< 0·001). Whole-grain foods were more available in the lunches served to children in the intervention school compared with the comparison school post-intervention (P< 0·0001). The ability to identify whole-grain foods by children in both schools increased, with a trend towards a greater increase in the intervention school (P= 0·06). Parenting scores for scales for role modelling (P< 0·001) and enabling behaviours (P< 0·05) were significantly greater for parents in the intervention school compared with the comparison school post-intervention.

Conclusions

The multi-component school-based programme implemented in the current study successfully increased the intake of whole-grain foods by children.
Jets of energetic particles generated by magnetic reconnection at a three-dimensional magnetic null
Authors: Dalla Silvia , Browning Philippa K.
Published: December 2007

Magnetic reconnection is a candidate mechanism for particle acceleration in a variety of astrophysical contexts. It is now widely accepted that reconnection plays a key role in solar flares, and reconstructions of coronal magnetic fields indicate that three-dimensional (3D) magnetic null points can be present during flares. We investigate particle acceleration during spine reconnection at a 3D magnetic null point, using a test particle numerical code. We observe efficient particle acceleration and find that two energetic populations are produced: a trapped population of particles that remain in the vicinity of the null, and an escaping population, which leave the configuration in two symmetric jets along field lines near the spine. While the parameters used in our simulation aim to represent solar coronal plasma conditions of relevance for acceleration in flares, the fact that the 3D spine reconnection configuration naturally results in energetic particle jets may be of importance in other astrophysical situations. We also compare the results obtained for the spine reconnection regime with those for the other possible mode of 3D reconnection, fan reconnection. We find that in the latter case energetic particle jets are not produced, though acceleration is observed.
Cosmic particle acceleration in astrophysical shear flows
Authors: Rieger Frank M. , Duffy Peter
Published: December 2007

Shear flows are ubiquitous phenomena in astrophysical environments. In the present contribution the stochastic acceleration of energetic charged particles by Fermi-type processes in relativistic shear flows is considered. We briefly summarize recent theoretical progress in the field of viscous shear acceleration and indicate its significance for particle energization in relativistic flows of AGNs and GRBs.
Populations of candidate black holes at redshift 7 or above
Authors: Koekemoer Anton M.
Published: December 2007

I will describe recent results on constructing samples of candidate active galactic nuclei (AGN) at or beyond redshift 7, probing several orders of magnitude fainter than the top end of the quasar luminosity function at redshift 6. These advances have been made possible by the advent of deep, wide multi-waveband surveys that enable the selection of samples of sources that are detected at radio or X-ray wavelengths but completely undetected at optical wavelengths to very deep limits. A variety of multi-band selection criteria are used to identify the high-redshift candidates and eliminate lower-redshift interlopers by means of extensive spectral energy distribution modelling. The resulting constraints on the numbers of high-redshift AGN at or above redshift 7 are used to examine the evolution of the AGN luminosity function at high redshift, and help understand the properties of the first supermassive black holes in the universe.
SN 1006 in context: from Type Ia supernova to remnant
Authors: Chevalier Roger A.
Published: December 2007

The evolutionary phases in going from a Type Ia supernova explosion to a 1000-yr-old remnant are reviewed. The explosion sets up the density and composition structure of the ejecta and can have radiative effects on the surroundings. The early shock interactions may be observable at radio and X-ray wavelengths if the circumstellar density is sufficiently high. The later interaction with the interstellar medium is affected by the collisionless shock physics and hydrodynamic instabilities.
Sternberg Astronomical Institute Supernova Catalogue, and radial distribution of supernovae in host galaxies
Authors: Bartunov O. S. , Tsvetkov D. Yu. , Pavlyuk N. N.
Published: December 2007

We present a new version of the Sternberg Astronomical Institite Supernova Catalogue and the results of our investigation of the supernova radial distribution in their host galaxies based on the new data.
Hayabusa and its adventure around the tiny asteroid Itokawa
Authors: Yoshikawa Makoto , Fujiwara Akira , Kawaguchi Jun'ichiro
Published: December 2007

Results of the Hayabusa mission to image and sample the asteroid Itokawa are summarized.
Joint Discussion 11 Pre-solar grains as astrophysical tools
Authors: Andersen Anja C. , Lattanzio John C.
Published: December 2007

With the first discovery of surviving pre-solar minerals in primitive meteorites in 1987 a new kind of astronomy emerged, based on the study of stellar condensates with all the detailed methods available to modern analytical laboratories. The pre-solar origin of the grains is indicated by considerable isotopic ratio variations compared with Solar System materials, characteristic of nuclear processes in different types of stars.
Pre-solar grains: outlook and opportunities for astrophysics
Authors: Nittler Larry R. , Alexander Conel M. O'D.
Published: December 2007

As pristine condensates from a large number of stars, pre-solar grains provide unique information on the sources, types, compositions and processing histories of dust in the Galaxy. However, their promise remains largely unfulfilled. Here we discuss some of the astrophysical problems for which pre-solar grains might provide important insights and constraints in coming years.
Sporadic radio emission of the Sun in the decametre range
Authors: Melnik Valentin N. , Konovalenko Alexander A. , Rucker Helmut O. , Lecacheux Alain
Published: December 2007

Results of the last observations of solar sporadic radio emission at the UTR-2 radio telescope (Kharkov, Ukraine) at the frequencies 10 - 30 MHz are presented. The use of new backend facilities, the DSP and 60-channel spectrometer, allows us to obtain data with time resolution up to 2 ms and frequency resolution of 12 kHz in the continuous frequency band 12 MHz. Usual Type III bursts, Type IIIb bursts, U- and J-bursts in the decameter range are discussed. Special attention is paid to detection and analysis of Type II bursts and their properties, newly discovered fine time structures of Type III bursts, Type III-like bursts, s-bursts, new observational features of drift pair bursts, and ‘absorption’ bursts.
Diffuse radio sources in clusters of galaxies: models and long-wavelength radio observations
Authors: Sarazin Craig L.
Published: December 2007

Clusters of galaxies contain several types of diffuse radio sources with very steep radio spectra which are associated with the cluster environment, including central radio bubbles, cluster radio relics, and cluster radio halos. Radio halos and relics are found only in merging clusters. Cluster radio relics may be produced by particle acceleration in merger shocks, while radio halos, may result from electron re-acceleration by turbulence produced by mergers. Secondary production of electrons and positrons by hadronic interactions also plays a role. If cluster radio halos and relics are related to mergers, then deep low frequency radio surveys could detect 1000's of clusters. Long-wavelength radio observations have a great potential to help us understand clusters and large scale structure, and can provide a diagnostic of cluster mergers, which affect the use of clusters in cosmological and dark energy studies.
Particle re-acceleration in the ICM and low-frequency observations
Authors: Brunetti Gianfranco
Published: December 2007

The particle reaceleration model is one of the most promising possibilities to explain the Mpc-scale diffuse radio emission detected in a number of galaxy clusters. Ongoing and future radio observations at low frequencies may help in constraining and testing this model.
Long-wavelength spectral studies of giant radio sources
Authors: Orrù Emanuela
Published: December 2007

We study giant radio sources at long wavelengths.
Special-purpose computing for dense stellar systems
Authors: Makino Junichiro
Published: December 2007

I'll describe the current status of the GRAPE-DR project. The GRAPE-DR is the next-generation hardware for N-body simulation. Unlike the previous GRAPE hardwares, it is programmable SIMD machine with a large number of simple processors integrated into a single chip. The GRAPE-DR chip consists of 512 simple processors and operates at the clock speed of 500 MHz, delivering the theoretical peak speed of 512/226 Gflops (single/double precision). As of August 2006, the first prototype board with the sample chip successfully passed the test we prepared. The full GRAPE-DR system will consist of 4096 chips, reaching the theoretical peak speed of 2 Pflops.
Tools for implementing the recent IAU resolutions
Authors: Kaplan George H. , Bangert John A.
Published: December 2007

We discuss tools for implementing the recent IAU resolutions, notably the USNO Circular 179 and the NOVAS software package.
Selecting highly-compact radio sources for the definition of the celestial reference frame
Authors: Charlot Patrick , Fey Alan L. , Ojha Roopesh , Boboltz David A. , Camargo J. I. B. , Collioud A.
Published: December 2007

We discuss the issue of selecting highly-compact radio sources for the definition of the celestial reference frame.
Retrieving diurnal and semi-diurnal signals in Earth rotation from VLBI observations
Authors: Brzeziński Aleksander , Bolotin Sergei
Published: December 2007

We discuss the issue of retrieving diurnal and semi-diurnal signals in Earth rotation from VLBI observations.
The 3D representation of the new transformation from the terrestrial to the celestial system
Authors: Dehant Véronique , de Viron Olivier , Capitaine Nicole
Published: December 2007

We offer a 3D representation of the new transformation from the terrestrial to the celestial system.
Joint Discussion 17 Highlights of recent progress in the seismology of the Sun and Sun-like stars
Authors: Bedding Timothy R. , Brun Allan S. , Christensen-Dalsgaard Jørgen , Crouch Ashley , De Cat Peter , García Raphael A. , Gizon Laurent , Hill Frank , Kjeldsen Hans , Leibacher John W. , Maillard Jean-Pierre , Mathis S. , Rabello-Soares M. Cristina , Rozelot Jean-Pierre , Rempel Matthias , Roxburgh Ian W. , Samadi Réza , Talon Suzanne , Thompson Michael J.
Published: December 2007

The seismology and physics of localized structures beneath the surface of the Sun takes on a special significance with the completion in 2006 of a solar cycle of observations by the ground-based Global Oscillation Network Group (GONG) and by the instruments on board theSolar and Heliospheric Observatory(SOHO). Of course, the spatially unresolved Birmingham Solar Oscillation Network (BiSON) has been observing for even longer. At the same time, the testing of models of stellar structure moves into high gear with the extension of deep probes from the Sun to other solar-like stars and other multi-mode pulsators, with ever-improving observations made from the ground, the success of theMOSTsatellite, and the recently launchedCoRoTsatellite. Here we report the current state of the two closely related and rapidly developing fields of helio- and asteroseimology.
Special Session 1 Large astronomical facilities of the next decade
Authors: Gilmore Gerard F. , Schilizzi Richard T.
Published: December 2007

The questions addressed in this large and popular meeting were: What mature proposals for the new large astronomical facilities of the next decade are available? When can they be funded? What international planning is underway?
The Virtual Observatory: what it is and where it came from
Authors: Lawrence Andrew
Published: December 2007

The Virtual Observatory (VO) is driven partly by new science goals, partly by external technological changes, and partly by the flood of data coming our way. More astronomy is done on line through organised ‘science ready’ archives, and with processed data (source catalogues etc) from large survey projects. Users assume on-line availability of anything useful. The normal methods to date are to download files and analyse them at home, but very likely in the future data will be analysed in situ and analysis software will be as standardised as data reduction software is now. Many science goals require combining data from multiple archives (e.g. crossmatching different wavelengths), and often demand the processing of huge amounts of data, e.g. rare object searches, computing correlation functions, etc. All users want to be ‘power users’.
Large surveys and the Virtual Observatory
Authors: Kuijken Konrad
Published: December 2007

Increasingly, large surveys of the sky in multiple wavelength bands are becoming an important part of how astronomy is being done. These surveys produce huge homogeneous datasets, and as such are prime material for dissemination and analysis through the VO. As an example, the KIDS survey (see Fig. 1), which will map 1500 square degrees of sky in ugriZYJHK using ESO's VST and VISTA telescopes, and which is expected to start in 2007, will generate some 15 TB of pixel data, as well as several TB of derived source parameters. More than 100 TB of raw data will have to be processed.
Mapping Galactic spiral arm structure: the IPHAS survey and Virtual Observatory access
Authors: Walton Nicholas A. , Drew Janet E. , Gonzalez-Solares Eduardo A. , Greimel Robert , Hopewell Ella C. , Irwin Mike J.
Published: December 2007

There is now considerable interest in how stellar streams in the Milky Way can be used to probe how the earlier merger history of our galaxy, which in turn can be related to hierarchical models of galaxy evolution.
Subject mediation approach for scientific problem solving in Virtual Observatories
Authors: Kalinichenko Leonid
Published: December 2007

There exist two principally different approaches to the organization of problem solving in VO: (i) information resources driven approach (choice and integrated definition of resources are made independently of the problem specification); and (ii) scientific problem driven approach (a specification of a problem domain is created, the relevant to the problem resources are identified and semantically mapped into the domain). Intrinsic difficulties of the first approach: semantic gap between resources and the problem, instability of global schema w.r.t. a set of resources, inability of automatic identification of resources for the problem. To implement the second approach a mediation technology is required. On the consolidation phase of the mediator the efforts of the scientific community are focused on the problem definition by specifying the mediator. During the operational phase relevant information resources are identified and expressed in terms of the mediator. Advantages of the mediator approach include truly semantic integration of heterogeneous resources due to their semantic mapping into the mediator; multiple subjects can be semantically integrated applying recursive structure of the mediators.
Wide field optical surveys
Authors: Yasuda Naoki
Published: December 2007

The products of optical wide-field survey are very valuable for their own purposes like the studies of large scale structure of galaxies, evolution of galaxies, Galactic structure and so on. At the same time optical view of sky will provide basic reference for the observation at other wavelength ranges. For this reason Palomar all sky survey has been used for various astronomical studies over 50 years. Now in the era of electronic devices, digital archives, and powerful computer systems, modern observation will replace the Palomar all sky survey.
Photometric identification of quasars from the Sloan Survey
Authors: Sinha Rameshwar P. , Philip Ninan S. , Kembahvi Ajit K. , Mahabal Ashish A.
Published: December 2007

We have developed a neural network based technique for identifying quasars from the photometric database of the Sloan Digital Sky Survey (SDSS). We have queried the SDSS data release 5 (DR5) to produce a dataset of spectroscopically identified samples of unresolved objects consisting of quasars and stars which forms the training set.
Near-IR properties of Spitzer sources
Authors: Gonzalez-Solares Eduardo A. , Walton Nicholas A. , Richards Anita M. S. , Tedds Jonathan A. ,   the AstroGrid Collaboration
Published: December 2007

We present an analysis of the near-IR properties of galaxies and quasars detected in the mid-IR by the Spitzer Space Telescope. Using optical photometry from the Wide Field Survey and near-IR fluxes from the First Data Release of the UKIDSS (Dye et al. 2006) survey we carry out a preliminary characterization of the surface density of different samples of galaxies and their clustering properties.
Antarctica – a case for 3D-spectroscopy
Authors: Kelz Andreas
Published: December 2007

DS or Integral-Field Spectroscopy (IFS) provides multiple spectra for each point of a 2-D field, rather than along a narrow, 1-D spectrograph slit only. Therefore, IFS does not require very accurate telescope pointing, nor do pre-assumptions about slit or aperture sizes have to be made. It avoids any ‘slit-losses’ due to seeing or atmospheric dispersion, which eliminates the need for any parallactic alignment or a dispersion compensator (see Fig. 1).
Evaluation of Minimal Trichoderma reesei Cellulase Mixtures on Differently Pretreated Barley Straw Substrates
Authors: Rosgaard Lisa , Pedersen Sven , Langston Jim , Akerhielm Derek , Cherry Joel R. , Meyer Anne S.
Published: December 2007

The commercial cellulase product Celluclast 1.5, derived from Trichoderma reesei (Novozymes A/S, Bagsværd, Denmark), is widely employed for hydrolysis of lignocellulosic biomass feedstocks. This enzyme preparation contains a broad spectrum of cellulolytic enzyme activities, most notably cellobiohydrolases (CBHs) and endo‐1,4‐β‐glucanases (EGs). Since the original T. reesei strain was isolated from decaying canvas, the T. reesei CBH and EG activities might be present in suboptimal ratios for hydrolysis of pretreated lignocellulosic substrates. We employed statistically designed combinations of the four main activities of Celluclast 1.5, CBHI, CBHII, EGI, and EGII, to identify the optimal glucose‐releasing combination of these four enzymes to degrade barley straw substrates subjected to three different pretreatments. The data signified that EGII activity is not required for efficient lignocellulose hydrolysis when addition of this activity occurs at the expense of the remaining three activities. The optimal ratios of the remaining three enzymes were similar for the two pretreated barley samples that had been subjeced to different hot water pretreatments, but the relative levels of EGI and CBHII activities required in the enzyme mixture for optimal hydrolysis of the acid‐impregnated, steam‐exploded barley straw substrate were somewhat different from those required for the other two substrates. The optimal ratios of the cellulolytic activities in all cases differed from that of the cellulases secreted by T. reesei. Hence, the data indicate the feasibility of designing minimal enzyme mixtures for pretreated lignocellulosic biomass by careful combination of monocomponent enzymes. This strategy can promote both a more efficient enzymatic hydrolysis of (ligno)cellulose and a more rational utilization of enzymes.
Reactive mercury in the troposphere: Model formation and results for Florida, the northeastern United States, and the Atlantic Ocean
Authors: Sillman Sanford , Marsik Frank J. , Al‐Wali Khalid I. , Keeler Gerald J. , Landis Matthew S.
Published: December 2007

We describe the development of a model for transport and photochemistry of atmospheric mercury at the regional scale, along with an application to the eastern United States and adjacent Atlantic Ocean and Gulf of Mexico, and comparison with aircraft‐based measurements in Florida. The model is the Community Multiscale Air Quality model (CMAQ) with modifications to include an integrated solution for gas phase and aqueous photochemistry. The expanded chemistry includes O3, NOx, organics, sulfur, halogens and mercury. Divalent reactive gaseous mercury (RGM) is formed slowly through gas phase reactions and removed rapidly by aqueous reactions in cloud water. Model results show that elevated RGM (up to 260 pg m−3) forms intermittently over the Atlantic Ocean in air masses that have a cloud‐free history. Aircraft measurements in Florida show RGM varying between 10 and 250 pg m−3 and increasing with altitude, a pattern that is consistent with model results. Ambient RGM would increase by 50% if aqueous reduction reactions were omitted. The model predicts that ambient elemental mercury and RGM anticorrelate in regions where RGM is produced photochemically and correlate in regions dominated by direct emissions. Model results also suggest positive correlations between RGM and SO2, reactive nitrogen and H2O2, which may be used to identify photochemically produced versus directly emitted RGM. RGM in the model is strongly correlated with O3 during pollution events, and ozone formation from anthropogenic precursors is predicted to cause a significant increase in RGM.
Upwelling and downwelling behavior in the Elder‐Voss‐Souza benchmark
Authors: Woods Juliette A. , Carey Graham F.
Published: December 2007

The Elder‐Voss‐Souza (EVS) problem is a standard benchmark for the numerical simulation of variable‐density flow and solute transport in a porous medium. However, a review of prior work shows that there is a wide variation in published results on plume structure that cannot entirely be explained by different choices of governing and constitutive equation or by discretization error and numerical error. This work presents results using a new numerical model and algorithms for a series of well‐calibrated comparison tests that are designed to elucidate the issue. In addition to the factors mentioned above, we consider the effects of initial and boundary conditions, domain geometry, and problem parameters such as the length of the source boundary segment and the buoyancy parameter in the associated Rayleigh number. It is found that these are key parameters determining the upwelling/downwelling plume behavior. More specifically, the values chosen for the EVS problem lie close to critical values that separate odd and even plume numbers. Consequently, perturbations to the model, mesh, and simulation variables may lead to different plume behavior.