bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Thrombectomy for Thrombosed Dialysis Grafts: Comparison of Adjunctive Treatments
Authors: Ko Po‐Jen
Published: December 2007

Background

Vascular surgeons often encounter dialysis graft failure in hemodialysis patients during their daily practice. Despite advances in percutaneous treatment, there remains a role for surgical thrombectomy of thrombosed dialysis grafts. This study was designed to investigate the long‐term outcome of dialysis graft thrombectomy and to examine the indications for and effectiveness of therapies adjuvant to Fogarty thrombectomy.

Methods

Surgical outcomes of 590 consecutive dialysis graft thrombectomies performed between 2001 and 2003 were retrospectively reviewed. The 590 cases were classified into four groups based on the procedure performed adjuvant to Fogarty thrombectomy: group A, surgical thrombectomy by Fogarty thrombectomy catheter alone; group B, thrombectomy plus intraoperative angioplasty of graft outlet; group C, thrombectomy plus sequential balloon angioplasty in subsequent intervention; group D, thrombectomy plus graft outlet surgical revision. Age, gender, co‐morbidity, and primary patency of grafts were reviewed and analyzed.

Result

The four groups exhibited similar demographic features and comorbidities (p > 0.05). Mean primary patency in the four groups was 1.99 ± 4.02, 7.21 ± 7.61, 8.35 ± 9.53, and 7.26 ± 6.99 (months), respectively. Survival curves for each group were determined by Kaplan‐Meier methods. Primary patency in group A was statistically inferior to all of the other three groups, whereas groups B, C, and D did not significantly differ with regard to graft patency.

Conclusions

Surgical thrombectomy alone is inadequate for treating a thrombosed dialysis graft. The underlying graft outlet stricture requires direct surgical revision or balloon angioplasty during surgery or intervention in the angiography suite to ensure long‐term patency of the graft.
Discrimination of Cod Liver Oil According to Wild/Farmed and Geographical Origins by GC and 13C NMR
Authors: Standal Inger B. , Praël Angelika , McEvoy Lesley , Axelson David E. , Aursand Marit
Published: December 2007

The objective of this study was to test the possibility of using lipid profiles obtained by gas chromatography (GC) and 13C nuclear magnetic resonance (NMR) in authentication of cod liver oils according to wild/farmed and geographical origin. GC and 13C‐NMR data of cod liver oil from wild and farmed fish from different locations in Norway and Scotland were obtained, and analyzed by principal component analysis (PCA) and linear discriminant analysis (LDA) to test if it was possible to differentiate oil from wild and cultured cod (Gadus morhua L.), and to further elucidate differences between fish from the different farms/catch area. Cod liver oils of wild and farmed origin were clearly separated in the PCA score plot both from GC and NMR data. From NMR data it was also possible to observe groupings based on geographical origin (farm/catch area) of the different samples. Using LDA with cross validation the wild/farmed classification rates were 97% for GC data and 100% for NMR data. In the classification of cod liver oils according to geographical origin (38 samples from six different farms/catch area), the correct classification rate was 63% for GC data and 95% for NMR data.
In Praise of Manipulation
Authors: DOWDING KEITH , VAN HEES MARTIN
Published: December 2007

Many theorists believe that the manipulation of voting procedures is a serious problem. Accordingly, much of social choice theory examines the conditions under which strategy-proofness can be ensured, and what kind of procedures do a better job of preventing manipulation. This article argues that democrats should not be worried about manipulation. Two arguments against manipulation are examined: first, the ‘sincerity argument’, according to which manipulation should be rejected because it displays a form of insincere behaviour. This article distinguishes between sincere and non-sincere manipulation and shows that a familiar class of social choice functions is immune to insincere manipulation. Secondly, the ‘transparency’ argument against manipulation is discussed and it is argued that (sincere or insincere) manipulation may indeed lead to non-transparency of the decision-making process, but that, from a democratic perspective, such non-transparency is often a virtue rather than a vice.
Bureaucratic passions and the colonies of modernity: an urban elite, city frontiers and the rural other in Germany, 1890–1920
Authors: JERRAM LEIF
Published: December 2007

This article analyses the ways the urban boundary and the landscapes beyond it were culturally conceived and physically manipulated in Munich between about 1890 and 1920. It highlights planning practice outside the ‘canon’ of planning history, showing the importance of localized decision-taking in urban design. The article explores cities as cultural constructs and material artefacts in Germany as part of a broader project linking planning history to broader historical investigation, and tries to bridge the gap between the ‘material’ city as a physical space, and the ‘cultural’ city of language and symbols.
The solar system: a laboratory for the study of the physics of particle acceleration
Authors: Lin Robert P.
Published: December 2007

A remarkable variety of particle acceleration occurs in the solar system, from lightning-related acceleration of electrons to tens of MeV energy in less than a millisecond in planetary atmospheres; to acceleration of auroral and radiation belt particles in planetary magnetospheres; to acceleration at planetary bow shocks, co-rotating interplanetary region shocks, shocks driven by fast coronal mass ejections, and possibly at the heliospheric termination shock; to acceleration in magnetic reconnection regions in solar flares and at planetary magnetopause and magnetotail current sheets. These acceleration processes often occur in conjunction with transient energy releases, and some are very efficient. Unlike acceleration processes outside the solar system, the accelerated particles and the physical conditions in the acceleration region can be studied through direct in situ measurements, and/or through detailed imaging and spectroscopy. Here I review recent observations of tens of MeV electron acceleration in the Earth's atmosphere and in the Earth's radiation belts, electron and ion acceleration related to magnetic reconnection in solar flares, electron acceleration to ≥ 300 keV in magnetic reconnection regions in the Earth's deep magnetotail, and acceleration of solar energetic particles (SEPs) by shocks driven by fast coronal mass ejections (CMEs).
Electron acceleration in solar flares: observations versus numerical simulations
Authors: Benz Arnold O. , Grigis Paolo C. , Battaglia Marco
Published: December 2007

We use RHESSI hard X-ray observations to constrain acceleration of solar flare electrons, generally considered to be a primary recipient of the released energy.
Solar flare particle heating via low-β reconnection
Authors: Krauss-Varban Dietmar , Welsch Brian T.
Published: December 2007

Observations give tight constraints on the temporal and spatial scales of particle heating in solar flares, and on the required efficiency. Electrons are accelerated into a quasi-thermal population of a few tens of keV. X- and γ-rays imply tails in electron and ion distributions reaching tens of MeV and above. Simple estimates indicate that all available electrons are accelerated at least once to moderate energies, pointing to an initial process resembling bulk heating rather than acceleration of a small or localized population. In the absence of effective collisions, wave-particle interactions are the prime candidate. Here we address the outstanding questions, (i) what process can heat the entire reconnecting plasma to the above energies, and (ii) what provides the free energy for wave-particle interactions? We propose a process in which initially the ions are heated and provide the free energy for electron heating and tail formation.
Physical conditions of the acceleration region of a solar flare with an unusually narrow gyrosynchrotron spectrum
Authors: de Castro Guillermo G. Giménez , Costa Joaquim E. Rezende , da Silva Adriana Válio Roque
Published: December 2007

During the rising phase of the August 30, 2002 X1.5 flare a short pulse with a total duration of 8 seconds was observed. Its background-subtracted radio spectrum ranges only from 5 to 12 GHz with a maximum flux density of approximately 900 s.f.u. at 7 GHz and a steep optically thin spectral index α ≃ 8. Maximum degree of polarization at 7 GHz is around 5%. The hard X-ray pulse emission above the background in the range of 30–150 keV observed by RHESSI is coincident in time with the microwave observation. Hard X-ray images reveal very compact (∼ 10″) footpoint sources. Below 30 keV, a thermal source is observed.
Galactic acceleration phenomena
Authors: Gallant Yves A.
Published: December 2007

I review the current status of our observational knowledge of prominent classes of particle accelerators in the Galaxy, namely shell-type supernova remnants (SNRs) and pulsar wind nebulae. I highlight in particular the contribution of the recent improvement in sensitivity of very-high-energy (VHE) γ-ray observations, which are currently the most direct probe of particle acceleration in the Galaxy up to energies of several hundreds of TeV.

Shell-type SNRs have long been proposed as sources of the Galactic cosmic rays. In recent years, X-ray observations have revealed very thin, non-thermal rims in many young SNRs, and I discuss the implications of these observations for magnetic field amplification and the maximum particle energy attainable by acceleration at the blast wave. I then review the current status of the evidence for accelerated nuclei in these objects, and summarise current uncertainties.

The most numerous class of identified Galactic VHE gamma-ray sources is currently that of pulsar wind nebulae (PWNe). The emission from these objects is generally assumed to be predominantly leptonic, and I outline the new information provided by VHE gamma-ray observations beyond what could be inferred from observations of synchrotron emission.
Particle acceleration by relativistic expansion of magnetic arcades
Authors: Takahashi Hiroyuki , Asano Eiji , Matsumoto Ryoji
Published: December 2007

We carried out relativistic force free simulations and Particle In Cell (PIC) simulations of twist injection into the magnetic arcades emerging on the surface of a magnetar. As the magnetic energy is accumulated in the arcades, they expand self-similarly. In the arcades, a current sheet is formed and magnetic reconnection takes place. We also carried out 2-dimensional PIC simulations for the study of particle acceleration through magnetic reconnection. As a result, the energy spectrum of particles can be fitted by a power-law.
Massive extragalactic eclipsing binaries
Authors: Bonanos Alceste Z.
Published: December 2007

Masses, radii and luminosities of distant stars can only be measured accurately in eclipsing binaries. The most massive eclipsing binary currently known is WR 20a, which consists of two ~ 80 M⊙ stars in a 3.7 d orbit. Analogs of WR 20a are bound to exist both in massive stellar clusters in our Galaxy and in nearby galaxies. The nearest ones are located in the clusters near the Galactic Center: the Center, Arches, and Quintuplet clusters. The severe amount of reddening in the galactic disk makes the study of galactic clusters challenging. However, with current 8-m class telescopes, the study of massive stars in nearby galaxies is also feasible. The nearest Local Group galaxies (LMC, SMC, M 31, M 33) provide the perfect laboratory for studying massive stars and determining their properties as a function of metallicity. Such studies will constrain models, confirm the dependence of evolution on metallicity and help understand the rate and nature of supernovae and gamma-ray bursts.
The masses of late-type WN stars
Authors: Gräfener Götz , Hamann Wolf-Rainer
Published: December 2007

We present recent results for galactic WNL stars, obtained with the new Potsdam Wolf-Rayet (PoWR) hydrodynamic model atmospheres. Based on a combination of stellar wind modeling and spectral analysis we identify the galactic WNL subtypes as a group of extremely luminous stars close to the Eddington limit. Their luminosities imply progenitor masses around 120 M⊙ or even above, making them the direct descendants of the most massive stars in the galaxy. Because of the proximity to the Eddington limit our models are very sensitive to the L/M ratio, thus allowing for a direct estimate of the present masses of these objects.
Inflation of luminous metal-rich WR stars – a clue to mass loss?
Authors: Pols Onno R.
Published: December 2007

We investigate the influence of metallicity and wind mass loss on the radii of luminous Wolf-Rayet stars.
The ejecta of η Carinae
Authors: Gull Theodore R.
Published: December 2007

High-dispersion spectroscopic observations of the neutral Homunculus and the ionized Little Homunculus, ejecta of η Car, are being analyzed to determine the relative abundances of metals. Thousands of lines of neutral and singly-ionized metals and molecules seen in the Homunculus suggest that this oxygen-, carbon-poor, nitrogen-, helium-rich gas contains very different dust grains likely devoid of metal oxides. The gas to dust ratio is likely much larger than the canonical 100:1 implying that the 12 M⊙ estimate of the ejecta is a lower limit.
Empirical evidence suggesting a stellar upper-mass limit
Authors: Oey M. Sally
Published: December 2007

While theoretical understanding remains to be clarified regarding the mechanisms that may or may not limit stellar masses, it is possible to empirically evaluate the existence of an upper-mass limit. ZAMS masses of the most massive stars have been estimated for a range of environments in our local Milky Way neighborhood and the Magellanic Clouds. Various statistical techniques demonstrate the existence of an upper-mass limit in this stellar sample.
Stellar and wind properties of massive stars in the central parsec of the Galaxy
Authors: Martins Fabrice , Genzel Reinhard , Eisenhauer Frank , Paumard Thibaut , Ott Thomas , Trippe Sascha , Gillessen Stefan
Published: December 2007

The stellar and wind properties of the new population of massive stars in the central parsec of the Galaxy are derived through quantitative analysis with atmosphere models.
Rotation, mass loss and nucleosynthesis
Authors: Meynet Georges
Published: December 2007

We list below a few problems whose resolution might bring new lights on the impacts of the first stellar generations on the early phases of the evolution of the galaxies.
Observations of galaxies at z>6. The properties of large, spectroscopic samples
Authors: Hu Esther M. , Cowie Lennox L. , Kakazu Yuko
Published: December 2007

Observed properties of spectroscopically confirmed galaxies at z≫5 and z≫6 based on selection from deep, multi-wavelength wide-field samples provide a picture of the current status of the properties of high-redshift galaxies and their evolution to yet higher redshifts.

In the current presentation, we use results of deep, wide-field spectroscopy with the multi-object Deimos spectrograph on Keck in combination with deep, wide-field multi-color imaging studies using the SuprimeCam CCD camera of Subaru for a number of fields, to evaluate the luminosity function of high-redshift galaxies and its evolution at z>6. High-redshift candidates are selected using both narrow-band Lyman alpha emission and broad-band colors with a high success-rate from a number of SuprimeCam (0.5 degree FOV) fields.

Luminosity functions and Lymanα emission line profiles and equivalent widths appear similar between samples at z≃5.7 and z≃6.5, and the galaxy distribution is structured both spatially and in redshift. A large amount of cosmic variance is seen in the distribution of z≫6 galaxies from field to field.

The observed properties are discussed in relationship to their impact on strategies for complementary optical surveys of high-redshift galaxies, and in relationship to surveys at very different wavelengths (X-ray, far-infrared, and submillimeter) that cover the same regions.
Properties of Lyα emitters at z≃6
Authors: Martin Crystal L. , Sawicki Marcin , Dressler Alan , McCarthy Patrick J.
Published: December 2007

We confirm the redshift of several z≃6 objects discovered by our imacs multislit emission-line survey. Their Lyα luminosities are lower than those of galaxies previously discovered using narrow-band imaging, as expected due to the excellent sky-supression inherent to this technique. Based on the line profiles of these objects, we argue that they are extremely young starbursts and find strong evidence for prominent galactic winds. This population of young galaxies is largely beyond the reach of current large surveys that use continuum selection.
Re-ionization imprints in high-z QSO spectra
Authors: Gallerani Simona , Choudhury T. Roy , Ferrara Andrea
Published: December 2007

We use a semi-analytical approach to simulate absorption spectra of QSOs at high redshifts with the aim of constraining the cosmic reionization history. More details are given in Gallerani et al. (2006) and references therein.
Spectroscopy of the near-infrared afterglow of GRB 050904 at z = 6.3
Authors: Kawai Nobuyuki
Published: December 2007

We present the optical/NIR spectrum of the afterglow of GRB 050904 obtained with the Faint Object Camera And Spectrograph on the Subaru 8.2m telescope taken 3.4 days after the burst. It is, as of June 2006, the only GRB with a known redshift larger than 6. The spectrum shows a clear continuum at the long wavelength end of the spectrum with a sharp cutoff at around 900nm due to Lyα absorption at a redshift of 6.3 with a damping wing. Little flux is present in the waveband shortward of the Lyα break. A system of absorption lines of heavy elements at redshift z = 6.295±0.002 were also detected, yielding a precise measurement of the largest known redshift of a GRB. Analysis of the silicon and sulphur absorption lines suggests a dense environment around the GRB with the metallicity larger than 0.1 solar, providing unique information on the galaxy and star forming region at z>6. This observation has shown that GRB is a powerful probe of the early universe.
Anisotropies of the infrared background and primordial galaxies
Authors: Cooray Asantha R.
Published: December 2007

We discuss anisotropies in the near-IR background between 1 to a few microns. This background is expected to contain a signature of primordial galaxies. We have measured fluctuations of resolved galaxies with Spitzer imaging data and we are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background.
Joint Discussion 8 Solar and stellar activity cycles
Authors: Kosovichev Alexander G. , Strassmeier Klaus G.
Published: December 2007

The solar magnetic field and its associated atmospheric activity exhibits periodic variations on a number of time scales. The 11-year sunspot cycle and its underlying 22-year magnetic cycle are, besides the 5-minute oscillation, the most widely known. Amplitudes and periods range from a few parts per million (ppm) and 2–3 minutes for p-modes in sunspots, a few 10 ppm and 10 minutes for the granulation turn around, a few 100 ppm and weeks for the lifetime of plages and faculae, 1000 ppm and 27 days for the rotational signal from spots, to the long-term cycles of 90 yr (Gleissberg cycle), 200 - 300 yr (Wolf, Spörer, Maunder minima), 2,400 yr from 14C tree-ring data, and possibly in excess of 100,000 yr.
Polar magnetic field reversals on the Sun
Authors: Benevolenskaya Elena E.
Published: December 2007

The polar magnetic fields on the Sun have been an attractive subject for solar researches since Babcock measured them in solar cycle 19. One of the remarkable features of the polar magnetic fields is their reversal during the maxima of 11-year sunspot cycles. I have present results of the investigations of the polar magnetic field using SOHO-mdi data. It is found, that the polar magnetic field reversal is detected with mdi data for polar region within 78°–88°. The North Pole has changed polarity in CR1975 (April 2001). The South reversed later in CR1980 (September 2001). The total unsigned magnetic flux does not show the dramatic decreasing during the polar reversals due to omnipresent bi-polar small-scale magnetic elements. The observational and theoretical aspects of the polar magnetic field reversals are discussed.
Flip-flop cycles in solar and stellar activity
Authors: Berdyugina Svetlana V.
Published: December 2007

We discuss flip-flop cycles in solar and stellar activity.
Photospheric stellar activity cycles
Authors: Oláh Katalin
Published: December 2007

Cycle lengths of active stars are derived from long-term photometric monitoring of their secular light variability. With the help of photographic data archives the lengths of the datasets are extended for HK Lac and V833 Tau. Using time-frequency analysis it is shown that the cycles are continuously changing in time. Thus, the reported cycle lengths derived by simple Fourier analysis are mean values that are valid only for a given time interval.
Global parameters of Type Ia supernovae
Authors: Leibundgut Bruno , Stritzinger Maximilian
Published: December 2007

Using simple physical assumptions we derived fundamental parameters including: the mass of synthesised56Ni, the ejecta mass, and the explosion energy of Type Ia supernovae. The methods have been described in several recent publications and comparison with other methods shows general consistency.
Exploring the global properties of Type Ia supernovae
Authors: Mazzali Paolo
Published: December 2007

While Type Ia supernovae are widely used as distance indicators, the reasons for the correlation between luminosity and light curve width that allows SNe Ia to be calibratable standard candles is not yet fully understood, and in particular the details of the explosion mechanism are still the subject of heated debate. We present the results of a systematic approach that uses the high-quality data collected by the European Research Training Network “The Physics of Type Ia Supernova Explosions” to map the supernova ejecta and to infer the properties of the explosion.
Venus Express
Authors: Svedhem L. Hakan
Published: December 2007

Results of the Venus Express mission to Venus are summarized.
Scientific results of the Mars Exploration Rovers, Spirit and Opportunity
Authors: Banerdt W. Bruce
Published: December 2007

Results of the Mars Exploration Rover mission to Mars are summarized.
What can pre-solar grains tell us about the solar nebula?
Authors: Huss Gary R. , Draine Bruce T.
Published: December 2007

Several types of pre-solar grains, grains that existed prior to solar system formation, have been found in the fine-grained components of primitive meteorites, interplanetary dust particles (IDPs), and comet samples. Known pre-solar components have isotopic compositions that reflect formation from the ejecta of evolved stars. Other pre-solar materials may have isotopic compositions very similar to solar system materials, making their identification as pre-solar grains problematic. Pre-solar materials exhibit a range of chemical and thermal resistance, so their relative abundances can be used to probe the conditions in the solar nebula. Detailed information on the relative abundances of pre-solar and solar-system materials can provide information on the temperatures, radiation environment, and degree of radial mixing in the early solar system.
Joint Discussion 12 Long wavelength astrophysics
Authors: Lazio T. Joseph W. , Kassim Namir E.
Published: December 2007

The greatest discoveries in astronomy have accompanied technological innovations that have opened new windows of the electromagnetic spectrum. One of the last poorly explored regions lies at wavelengths longer than 3 m (100 MHz) to the ionospheric cutoff around 30 m (10 MHz). In the past, variations in the ionosphere have limited ground-based instruments to small (< 5 km) apertures and hence relatively coarse angular resolution and low sensitivity.
Radio emission from the Sun, planets, and the interplanetary medium
Authors: Bastian Timothy S.
Published: December 2007

A brief review is given of radio phenomena on the Sun, the planet Jupiter, and the interplanetary medium and its outer boundary. A brief aside is made to draw parallels between radio emission from Jupiter and extrasolar planets.
NRAO 43-m telescope operation at 170-1700 MHz: a Bi-Static Radar Collaboration
Authors: Langston Glen
Published: December 2007

The NRAO 43m telescope has been refurbished and begun regular observations in the frequency range 170 - 1700 MHz. The 43 m operations support a Bi-Static Radar Collaboration to measure the Earth's ionospheric turbulence. Researchers from Chalmers University of Technology in Sweden have designed and built a unique design wide-band feed, 150 - 1700 MHz. Lincoln Laboratories/MIT has packaged the feed with room temperature low noise amplifiers. Lincoln Laboratories has installed a high-dynamic range RF system together with a wide-band sampler system. The NRAO operates the 43 m telescope according to schedules authored by Lincoln Laboratories. Currently the 43 m telescope is tracking spacecraft 48 hr a week. The tracking antenna operation is completely automated. A group at MIT/Haystack have installed a second radar experiment at the 43 m as well as an array of 6 ‘discone’ antennas. Their experiment is testing the use of reflected FM radio stations as probes of the ionosphere.
Particle acceleration processes in the cosmic large-scale structure
Authors: Enßlin Torsten A. , Pfrommer Christoph
Published: December 2007

The energetic shock waves associated with the violent large-scale structure formation process are able to accelerate relativistic electrons and protons. The induced non-thermal emission, especially at long radio wavelength, provides a fascinating perspective into structure formation, the relativistic Universe, and cosmic magnetic fields.
Cosmic re-onization: theoretical modelling and forthcoming observations
Authors: Ciardi Benedetta
Published: December 2007

With the advent in the near future of radio telescopes such as LOFAR and the SKA, a new window on the high-redshift Universe will be opened. In particular, it will be possible, for the first time, to observe the 21-cm signal from the diffuse IGM prior to its complete re-ionization and thus probe the ‘dark ages’. I discuss the theoretical modelling of the re-ionization process and its observability through the 21-cm signal and the CMB anisotropies.
Joint Discussion 13 Exploiting large surveys for Galactic astronomy
Authors: Corbally Christopher J. , Bailer-Jones Coryn A.L. , Giridhar Sunetra , Lloyd Evans Thomas H.
Published: December 2007

This summary of JD13, Exploiting large surveys for Galactic astronomy, is based on the talks that were given during the meeting and/or submitted to the full proceedings which appeared in MemSAI 77 no. 4, 2006. The electronic version of this MemSAI volume also has the abstracts and images of the posters that were displayed and discussed during JD13. Here can only be listed their titles and authors. A panel discussion followed the talks, and a summary of the topics covered is added. Finally, there come the concluding remarks.
Stellar evolution and feedback connections to stellar dynamics
Authors: D'Antona Francesca
Published: December 2007

Until a few years ago, the common paradigm for the formation of Globular Clusters (GCs) was that they constitute a ‘simple stellar population’ in which all the stars were formed from a chemically homogeneous cluster medium within a relatively short interval of time, at the beginning of the galactic life. In recent years, the spectroscopic information on the low luminosity (turnoff) cluster stars have extended to the unevolved stars the recognition that chemical anomalies are a common feature of GCs and not an exception. This has provoked a revolution in the simple view of GC formation, and requires an adequate dynamical modelling including gas dynamics. It is by now well accepted that at least two different stellar components are common in most GCs. These are almost unequivocally identified with (i) a first stellar generation, which gave origin to stars of all masses; and (ii)) a second generation, born from the ejecta of the most massive asymptotic giant branch stars of the first generation, in the first 100–200 Myr from the first burst of star formation. A ‘third’ population is present only in some GCs, and is more difficult to be understood. It is characterized by stars having a huge helium content (Y ≃ 0.4, if stellar modelling is reasonable) and extreme chemical anomalies in the proton capture elements (Na, O, Al). The status of understanding of the GC properties, based on our most recent models of stellar evolution, is discussed.
Stellar dynamics and feedback connections to stellar evolution
Authors: Ivanova Nataliya M.
Published: December 2007

In dense stellar systems, dynamical interactions between objects inevitably lead to frequent formation of exotic stellar objects and multiple systems, thereby imposing new questions for the stellar evolution theory. The evolutionary path of such systems could be different from that of the unperturbed objects, therefore, we must re-evaluate their evolutionary treatment to clarify their consequent dynamical evolution. We review briefly the classes of important dynamical encounters and discuss several post-encounter outcomes that may require more detailed attention or development of a new treatment in stellar evolution: evolution of complex merger products, spun-up stars, binaries with stripped giants and triples.
Multiple populations in globular clusters
Authors: Piotto Giampaolo
Published: December 2007

I briefly present the most relevant observational facts supporting the idea of one or more star formation episodes in globular clusters.
Models of M 67
Authors: Hurley Jarrod R.
Published: December 2007

The old open cluster M 67 is an ideal test case for current star cluster evolution models because of its dynamically evolved structure and rich stellar populations that show clear signs of interaction between stellar, binary and cluster evolution. Here we discuss a direct N-body model of M 67. This model of 12,000 single stars and 12,000 binaries is evolved from zero-age and takes full account of cluster dynamics as well as stellar and binary evolution. At an age of 4 Gyr the model cluster matches the mass and structure of M 67 as constrained by observations. We discuss the role of the primordial binary population and the cluster environment in shaping the nature of the stellar populations of M 67, with a focus on X-ray binaries and blue stragglers.
Joint Discussion 15 New cosmology results from the Spitzer Space Telescope
Authors: Helou George , Frayer David T.
Published: December 2007

We present and discuss recent new results from the Spitzer Space Telescope and their impact on cosmology.
Joint Discussion 16 Nomenclature, precession and new models in fundamental astronomy
Authors: Capitaine Nicole , Vondráak Jan , Hilton James L.
Published: December 2007

The IAU Joint Discussion 16 was held at the IAU XXVI General Assembly in Prague, in August 2006. The title of the meeting was Nomenclature, Precession and new models in Fundamental Astronomy. Applications and scientific contribution to astronomy. It was organized by IAU Division I (Fundamental Astronomy) and Commission 19 (Earth Rotation), with the participation of IAU Division, X (Radio Astronomy) and all the Division, I Commissions, as well as with the support of the International Association of Geodesy (IAG). The Scientific Organizing Committee was made up of the three organizers and the representatives of these scientific bodies.
Problems of the reference radio source selection
Authors: Titov Oleg A.
Published: December 2007

We discuss problems of the reference radio source selection.
Models for high-precision spacecraft and planetary and lunar ephemerides
Authors: Standish E. Myles , Williams James G.
Published: December 2007

We discuss models for high-precision spacecraft and planetary and lunar ephemerides.
Accurate harmonic development of Lunar ephemeris LE-405/406
Authors: Kudryavtsev Sergey M.
Published: December 2007

We discuss an accurate harmonic development of Lunar ephemeris LE-405/406
Accurate optical reference catalogs
Authors: Zacharias Norbert
Published: December 2007

Current and near future all-sky astrometric catalogs on the ICRF are reviewed with the emphasis on reference star data at optical wavelengths for user applications.
Scientific potential of the future space astrometric missions
Authors: Lindegren Lennart
Published: December 2007

We discuss the scientific potential of the future space astrometric missions.
Does the magnetic field in the fluid core contribute a lot to Earth nutation?
Authors: Huang Cheng-Li , Dehant Véronique , Liao Xin-Hao , de Viron Olivier , van Hoolst Tim
Published: December 2007

We discuss the influence of the magnetic field in the fluid core to the Earth's nutation.
James Webb Space Telescope
Authors: Stockman Hervey S.
Published: December 2007

The James Webb Space Telescope (JWST) is the scientific successor to the Hubble and Spitzer missions. Its wavelength range (1 - 28μm) and sensitivity (1 nJy - 1 μJy) complement the submillimeter facilities of the coming decade, Herschel and ALMA. The JWST development is on schedule for a June 2013 launch to L2 on an Ariane 5.
ESA Space Science Programme, Cosmic Vision 2015-2025, for astrophysics
Authors: Turon Catherine
Published: December 2007

After a brief description of the ESA Science Programme, the long-term plan for Astrophysics is described, as well as possible strategies for its implementation.
An introduction to major astronomical projects in China and plans for the future
Authors: Cui Xiangqun
Published: December 2007

This report is a general introduction to Chinese major astronomical projects. It includes the ongoing project ‘Large Sky Area Multi-Object Fiber Spectroscopic Telescope’ (LAMOST), and three major projects which have finished their feasibility study and development of key technologies: Five-hundred-meter Aperture Spherical (radio) Telescope (FAST); Space Solar Telescope (SST); Hard X-ray Modulation Telescope (HXMT). Among them, FAST and HXMT have been approved by government in 2006, and SST is pending for the next five years plan. Besides these major projects, a site survey in the west of China, a plan for developing Antarctic Dome A for astronomy, and a preliminary study of Chinese future giant optical/infrared telescopes are also briefly introduced.
Special Session 3 The Virtual Observatory in action: new science, new technology, and next generation facilities
Authors: Walton Nicholas A. , Lawrence Andrew , Williams Roy
Published: December 2007

The vision of the Virtual Observatory (VO) is to make access to astronomical databases as seamless and transparent as browsing the World Wide Web is today. It will federate the data flows from current and future facilities and large scale surveys, and the computational resources and new tools necessary to fully exploit them. This requires both technological developments and an international commitment to standardisation and working culture. Increasingly, it will alter the way that astronomers do science, and the way that future facilities and projects plan for their data management, and the scientific exploitation of their data. It will make an impact on a wide variety of astronomical topics, but especially those using very large databases, and those needing a multiwavelength approach, or more generally the use of multiple archives.
A VO-based solution to the origin of soft X-ray emission in obscured AGN
Authors: Guainazzi Matteo , Barbarisi I. , Bianchi Stefano , Cerviño Miguel , Osuna Pedro , Salgado Jesus
Published: December 2007

Recent high-resolution imaging observations with Chandra have unveiled a striking similarity between the Narrow Line Region (NLR) and the diffuse soft (0.1-keV) emission-line dominated X-ray morphologies in a number of obscured Active Galactic Nuclei (AGN) on scales as large as 0.1-2kpc (Bianchi et al., 2006, A&, 448, 499). This discovery suggests a strong link between these components, which points toward a common physical origin. AGN photo-ionization is a natural explanation, consistent with soft X-ray high-resolution spectroscopy (Guainazzi & Bianchi, 2006, submitted). However, the possibility that the bulk of this component is generated by ‘local’ photo-ionization induced by shocks in the interaction between a radio jet and the interstellar matter, or by mechanical heating in regions of intense star formation cannot be ruled out yet.
Determination of radio spectra from catalogues and identification of gigahertz peaked sources using the Virtual Observatory
Authors: Vollmer Bernd , Derriere Sebastian , Krichbaum Thomas P. , Boch Thomas , Gassmann Brice , Davoust Emmanuel , Dubois Pascal , Genova Françoise , Ochsenbein François , Driel Wim van
Published: December 2007

We have used the 20 largest radio continuum catalogues contained in VizieR (CDS) to determine radio continuum spectra between wavelengths of 2cm and 1m. For 67,000 out of the 3.5 million catalogued sources we could extract radio spectra with measurements at at least three independent frequencies (Vollmer et al. 2005, A&A, 431, 1177). These have been validated by comparison with existing spectral indices from the literature. This work allowed us to investigated the compatibility between the 20 radio continuum catalogues (Vollmer et al. 2005, A&A, 436, 757). Our radio spectra data base was searched for Gigahertz peaked source candidates, which we then observed quasi-simultaneously with the Effelsberg 100-m radio telescope at 6cm (4.85GHz), 2.8cm (10.45GHz), and 9mm (32GHz). This represents an efficient procedure to discover new Gigahertz peaked sources, which are believed to be AGNs at the beginning of their radio evolution. In our sample of more than 200 sources we find more than 50% bona fide GPS sources. In addition, we can estimate the percentage of variable sources in our multi-epoch sample of radio sources which show an inverted spectrum. We are generalizing the method by using VO capabilities to: (i) identify pertinent radio catalogues in the VO registry using Uniform Content Descriptions (UCDs); all catalogues containing a user defined set of UCDs (e.g., PHOT_FLUX_RADIO* for a radio flux, POS_EQ_RA and POS_EQ_DEC for the position) are located in the VO registry and listed for further queries; (ii) extract relevant data, the user can easily assign a row of a given catalogue to a row of a previously defined output catalogue; and (iii) normalize these for the determination of radio spectra; units can be converted, aconymes can be created, flags can be created, etc. This procedure allows to homogenize the information retrieved from a heterogenuous set of catalogues. For this purpose software allowing semi-automated information retrieval is being developed at the CDS within the framework of the European VO-TECH project. The potential usage of all available radio catalogues will strongly increase the number of independent radio source cross-correlations and radio spectra. Our aim is to include more than 100 radio catalogues into the radio spectra determination software. The results are progressively being made available to the community through the CDS services.
Towards a VO compliant ESO science archive
Authors: Padovani Paolo
Published: December 2007

Data centres have a major role in the Virtual Observatory (VO), as they are the primary source of astronomical data. The VO cannot (and does not) dictate how a data centre handles its own archive. However, ‘VO-layer’ is needed to ‘translate’ any locally defined parameter to the standard (i.e., International Virtual Observatory Alliance compliant) ones. The longer term vision of the VO is also to hide away any observatory/telescope/instrument specific detail and work in astronomical units, for example, ‘wavelength range’ and not grism or filter name. Data providers are then advised to systematically collect metadata (‘data about data’) about the curation process, assign unique identifiers, describe the general content (e.g., physical coverage) of a collection, and provide interface and capability parameters of public services. Finally, the VO will work at its best with high-level (‘science-ready’) data, so that the VO user is spared as much as possible any complex and time consuming data reduction. Data centres should then make an effort to provide such data.
‘Retooling’ data centre infrastructure to support the Virtual Observatory
Authors: Gaudet Séverin
Published: December 2007

The Canadian Astronomy Data Centre manages a heterogeneous collection of data from the following ground and space-based telescopes: CFHT, DRAO, FUSE, Gemini, HST, JCMT, and MOST. The archive data models implemented for these data collections are ten years old and pre-date two important developments: the Virtual Observatory and the systematic generation and management of data products. Three years ago, we began the process of supporting access to processed data products through IVOA protocols such as SIA by building a layer over the archive data models. Today, we now realise that this approach of layering VO models on archive models is not sufficient and that every archive must be re-tooled to properly support the VO – from the storage model through to the query, processing and access models. The CADC has begun an ambitious software development effort to implement a new infrastructure to serve both telescope archive and Virtual Observatory needs.
Prototype development for a Hubble Legacy Archive
Authors: Whitmore Bradley C. , Jenkner Helmut , Miller Warren , Koekemoer Anton M.
Published: December 2007

The Space Telescope Science Institute (STScI), in collaboration with the European Coordinating Facility (ECF), and the Canadian Astronomy Data Centre (CADC), is studying the development of an enhanced archive for the Hubble Space TelescopeHST), with the goal of improving the scientific value of the data. The primary enhancements would be:
Brown dwarfs and star forming regions in the framework of the Spanish Virtual Observatory
Authors: Solano Enrique , Martín Eduardo L. , Caballero José A.
Published: December 2007

In this paper we describe three lines of work that are being developed in the framework of the Spanish Virtual Observatory.
Connecting the literature with on-line data
Authors: Eichhorn Guenther , Accomazzi Alberto , Grant Carolyn S. , Henneken Edwin A. , Kurtz Michael J. , Thompson Donna M. , Murray Stephen S.
Published: December 2007

Over the last few years there has been considerable progress in linking the published scholarly literature with on-line data. This will greatly help with data discovery and aid the efforts to the VO.
Astrophysical integrated research environment
Authors: Zhou Jianfeng , Yang Yang
Published: December 2007

Astrophysical Integrated Research Environment (AIRE), aims to integrate astrophysical data, analysis software and astrophysical knowledge into an easy-to-use Internet based environment. Therefore, astrophysicists from different institutes can constitute virtual research groups which are favorable to study some complex multi-band astrophysical phenomena. The AIRE was put into use in Center for Astrophysics, Tsinghua university in 2003. Up to now, there are 219 advanced users in this environment. Several astrophysical researches base on AIRE have generated some important published results.
Mexican Virtual Solar Observatory project
Authors: Santillán Alfredo J. , Hernández Liliana , Salas Guillermo , Sánchez Antonio , González Alejandro , Franco José
Published: December 2007

The Virtual Solar Observatory (VSO) concept outlines a software environment for searching, obtaining and analyzing data from archives of solar data that are distributed at many different observatories around the world (Hill 2006, in this volume). The VSO, however, not only provides fast and reliable access to the existing data of Solar Active Regions, but also represents a powerful and unique tool to perform numerical simulations of the evolution and present state of solar phenomena. Two centers at UNAM, the Institute of Astronomy (IA) and the Supercomputer Center (DGSCA), along with the Sonora University, are working together to create the Mexican Virtual Solar Observatory (MVSO) that will be part of a wider national effort.
Solar active region emergence and flare productivity
Authors: Dalla Silvia C. , Fletcher Lyndsay , Walton Nicholas A.
Published: December 2007

We use the workflow capabilities of the AstroGrid Virtual Observatory system () to analyse the relation between flare productivity and location of Active Region (AR) emergence on the Sun. Specifically, we investigate whether emergence of a new region near existing ones results in increased productivity of the new and/or pre-existing AR. To address this question, we build a series of workflows that perform queries to catalogues of regions and flares, and operations on the results of the queries. There is a strong East-West asymmetry in the location of emergence of new regions. We do not find a significant difference between the flaring rate of paired and isolated regions, when we choose a value of 12° as the cutoff between the two populations.
Special Session 5 Astronomy for the developing world
Authors: Hearnshaw John B. , Martinez Peter
Published: December 2007

The International Astronomical Union has a strong commitment to the development of astronomical education and research throughout the world, especially in those countries developing economically. This commitment is in part through the work of IAU Commission 46 for astronomy education and development. Within that commission, the Program Group for the World-wide Development of Astronomy (PGWWDA) coordinates many of these activities, promoting the development of astronomy in developing countries.
Special Session 6 Astronomical data management
Authors: Norris Raymond P. , Andernach Heinz J. , Eichhorn Güenther , Genova Françoise , Griffin R. Elizabeth , Hanisch Robert J. , Kembhavi Ajit K. , Kennicutt Robert C. , Richards Anita M.S.
Published: December 2007

We present a summary of the major contributions to the Special Session on Astronomical Data Management held at the IAU XXVI General Assembly in Prague in 2006. While recent years have seen enormous improvements in access to astronomical data, and the Virtual Observatory aims to provide astronomers with seamless access to on-line resources, more attention needs to be paid to ensuring the quality and completeness of those resources. For example, data produced by telescopes are not always made available to the astronomical community, and new instruments are sometimes designed and built with insufficient planning for data management, while older but valuable legacy data often remain undigitised. Data and results published in journals do not always appear in the data centres, and astronomers in developing countries sometimes have inadequate access to on-line resources. To address these issues, an ‘Astronomers' Data Manifesto’ has been formulated with the aim of initiating a discussion that will lead to the development of a ‘code of best practice’ in astronomical data management.
Ten years from the Antarctic Sub-millimeter Telescope and Remote Observatory
Authors: Martin Christopher L.
Published: December 2007

Beginning with the winter season of 1995 and for the next ten years, the Antarctic Sub-mm Telescope and Remote Observatory (AST/RO, Stark et al. 1997; Stark et al. 2001; ), a 1.7m diameter, offset Gregorian telescope located at an altitude of 2847m at the Amundsen-Scott South Pole Station collected sub-mm and Terahertz data in the 1.3mm to 200μm wavelength bands. From its location just a few hundred meters away from the geophysical South Pole, AST/RO was the first sub-mm telescope to over-winter on the polar plateau, a location uniquely suited to high quality sub-mm observations due its very low humidity, high atmospheric stability and thin troposphere (Chamberlin et al. 1997).