bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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.
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

ABSTRACTThis 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

AbstractA 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).
Solar flare particle heating via low-β reconnection
Authors: Krauss-Varban Dietmar , Welsch Brian T. 
Published: December 2007

AbstractObservations 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.
Galactic acceleration phenomena
Authors: Gallant Yves A. 
Published: December 2007

AbstractI 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

AbstractWe 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.
The masses of late-type WN stars
Authors: Gräfener Götz , Hamann Wolf-Rainer 
Published: December 2007

AbstractWe 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.
The ejecta of η Carinae
Authors: Gull Theodore R. 
Published: December 2007

AbstractHigh-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

AbstractWhile 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

AbstractThe 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.
Observations of galaxies at z>6. The properties of large, spectroscopic samples
Authors: Hu Esther M. , Cowie Lennox L. , Kakazu Yuko 
Published: December 2007

AbstractObserved 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

AbstractWe 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

AbstractWe 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

AbstractWe 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

AbstractWe 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.
Polar magnetic field reversals on the Sun
Authors: Benevolenskaya Elena E. 
Published: December 2007

AbstractThe 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.
Photospheric stellar activity cycles
Authors: Oláh Katalin 
Published: December 2007

AbstractCycle 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.
Exploring the global properties of Type Ia supernovae
Authors: Mazzali Paolo 
Published: December 2007

AbstractWhile 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.
What can pre-solar grains tell us about the solar nebula?
Authors: Huss Gary R. , Draine Bruce T. 
Published: December 2007

AbstractSeveral 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.
NRAO 43-m telescope operation at 170-1700 MHz: a Bi-Static Radar Collaboration
Authors: Langston Glen 
Published: December 2007

AbstractThe 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.
Cosmic re-onization: theoretical modelling and forthcoming observations
Authors: Ciardi Benedetta 
Published: December 2007

AbstractWith 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

AbstractThis 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

AbstractUntil 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

AbstractIn 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.
Models of M 67
Authors: Hurley Jarrod R. 
Published: December 2007

AbstractThe 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.
James Webb Space Telescope
Authors: Stockman Hervey S. 
Published: December 2007

AbstractThe 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.
An introduction to major astronomical projects in China and plans for the future
Authors: Cui Xiangqun 
Published: December 2007

AbstractThis 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.
Astrophysical integrated research environment
Authors: Zhou Jianfeng , Yang Yang 
Published: December 2007

AbstractAstrophysical 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.