bluuebunny/crossref_metadata_2025_split huggingface dataset:
Square Kilometre Array Station Configuration Using Two-Stage Beamforming
Authors: Jiwani Aziz , Colegate Tim , Razavi-Ghods Nima , Hall Peter J. , Padhi Shantanu , bij de Vaate Jan Geralt 
Published: March 2013

AbstractThe lowest frequency band (70–450 MHz) of the Square Kilometre Array (SKA) will consist of sparse aperture arrays grouped into geographically localised patches or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tiles on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area is similar between layouts. At lower frequencies, the regular tile significantly reduces effective area, hence sensitivity. The effective area is highest for a two-stage irregular station, but it requires a larger station extent than the other two layouts. Although there are cost benefits for stations with two-stage beamforming, we conclude that more accurate station modelling and SKA-low configuration specifications are required before design finalisation.
Modeling of electric arcs: A study of the non-convective case with strong coupling
Authors: WRIGHT D. , DELMONT P. , TORRILHON M. 
Published: March 2013

AbstractIn this paper, we investigate a mathematical model for electric arcs. The model is based on the equations of magnetohydrodynamics, where the flow and heat transfer in a plasma is coupled to electrodynamics. Our approach neglects convection and yields a reaction–diffusion model that includes only the core phenomena of electric arcs: Ohmic heating and nonlinear electric conductivity. The equations exhibit interesting mathematical properties like non-unique steady states and instabilities that can be linked to electric arc properties. Additionally, a 3D axisymmetric simulation of the creation and extinction of an electric arc is presented based on a strongly coupled numerical algorithm for the non-convective model. The approach is especially suited for high-current arcs where strong coupling becomes necessary.
The Advance of the Party: Transformation or Takeover of Urban Grassroots Society?
Authors: Thornton Patricia M. 
Published: March 2013

AbstractWhile existing scholarship focuses attention on the impact of state control and repression on Chinese civil society, the increasingly independent role of the Communist Party has been largely overlooked. This article reviews the Party's drive to “comprehensively cover” grassroots society over the previous decade against the theoretical debate unfolding among Chinese scholars and Party theoreticians regarding the Party's role with respect to civil society. Focusing on greater Shanghai, frequently cited as a national model of Party-building, I describe the Party's advance and the emergence of Party-organized non-governmental organizations (PONGOs), a new hybrid form of social organization sponsored and supported by local Party committees. I argue that these developments invite a reconsideration of our understandings of the ongoing “associational revolution” and of the Party's relationship to China's flourishing “third realm.”
The Demography of Chinese Nationalism: A Field-Experimental Approach
Authors: Hoffmann Robert , Larner Jeremy 
Published: March 2013

AbstractEmpirical evidence concerning the demographics and development of Chinese nationalism is sparse but important for scholarship and policy. Its collection entails methodological challenges in access and reliability. We conducted a field experiment to measure nationalism in incentive-compatible choices among a diverse group of 447 Chinese subjects in a field setting. Our results demonstrate greater nationalism in female, older, less affluent and more rural respondents. We also find support for nationalism in professional and educated individuals. Our results provide qualified support for a middle-class nationalism in China.
Typing ofSalmonella entericaserovar Infantis isolates from 51 outbreaks in Germany between 1974 and 2009 by a novel phage-typing scheme
Authors: MILLER T. , BRAUN P. G. , FEHLHABER K. , PRAGER R. , PFEIFER Y. , RABSCH W. 
Published: March 2013

SUMMARYWe developed a new phage-typing method and evaluated its application in combination withXbaI macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) as a useful tool for the long-term epidemiology ofSalmonella entericaserovar Infantis. In this study, we investigated 1008S.Infantis isolates recovered from humans, various animal species and food products from 1973 to 2009. The typing scheme is based on 17 typing phages, defining 61 different patterns within the strain collection. The experiments showed that phage typing is a reliable method for differentiation of outbreaks and sporadic clinical cases as well as for elucidation of chains of transmission. The combined analysis of phage typing and PFGE revealed the existence of epidemic clones with a high stability over time like PT29/XB27 which was identified in nosocomial salmonellosis, community outbreaks as well as in broiler chickens from 2002 to 2009.
Epidemiology of norovirus gastroenteritis in Germany 2001–2009: eight seasons of routine surveillance
Authors: BERNARD H. , HÖHNE M. , NIENDORF S. , ALTMANN D. , STARK K. 
Published: March 2013

SUMMARYWe analysed data on laboratory or epidemiologically confirmed cases (n = 856 539) and on outbreaks (n = 31 644) notified during week 31 (2001) to week 30 (2009), and performed molecular typing of specimens from 665 outbreaks. We aimed at identifying demographic and molecular characteristics to inform on potential additional approaches to prevent disease spread in the population. The mean incidence by norovirus season (week 31 in one year to week 30 in the following year) was 130 (range 19–300) cases/100 000 population and was highest in persons aged <5 years (430/100 000) and ⩾75 years (593/100 000). The proportion hospitalized in community-acquired cases was 8–19% per season. The mean norovirus-associated mortality was 0·05/100 000 per season and 0·5/100 000 in the ⩾75 years age group. Most outbreaks with known setting (75%) occurred in hospitals (32%), nursing homes (28%), households (24%) and childcare facilities (10%). GII strains dominated in the outbreak specimens. GII.4 strains were found in 82% of nursing home outbreaks, 85% of hospital outbreaks, and 33% of childcare facility and school outbreaks. Cases in younger individuals were notified earlier during the season than adult cases, and outbreaks in childcare facilities and schools preceded those in nursing/residential homes, hospitals and private households. We suggest future studies to investigate more closely potential transmission patterns between children and adults.
Holy Shroud Exhibition 2010: Health Services During a 40-Day Mass-Gathering Event
Authors: Bortolin Michelangelo , Ulla Marco , Bono Alessia , Ferreri Enrico , Tomatis Mariano , Sgambetterra Sergio 
Published: March 2013

AbstractIntroductionMass-gathering events require varying types and amounts of medical resources to deal with patient presentations as well as careful planning for environmental health management. The Holy Shroud Exhibition was hosted in Torino, Italy, between April and May 2010. The venue was a unique mass-gathering event which lasted several weeks. It was held in a limited area in the center of the city and it was attended by a large and heterogeneous population. A dedicated Health Care Service was created for the event.MethodsThis study is a retrospective analysis of clinical presentations of patients who were managed by the Medical Services during the event. The main study outcomes included Patient Presentation Rate (PPR), type of injuries and illnesses, and the Transport to Hospital Rate (TTHR).ResultsThe PPR and TTHR were both low (0.27 and 0.039 respectively). The majority of patients presented with low severity codes and no sudden cardiac death (SCD) or cardiac arrest occurred. Cardiac and trauma emergencies were most frequent categories of presentation. A number of pediatric patients (19.37%) were treated by the event Medical Service. Approximately two million persons participated in the 40-day event.ConclusionThe experience for this 40-day event supported having an on-site, organized, dedicated Medical Service that decreased overcrowding of the local Emergency Medical System and hospitals. It is recommended that, for such events, there be recruitment of emergency physicians with experience in mass-gathering events, recruitment of pediatricians, and training for professionals during the planning process.BortolinM, UllaM, BonoA, FerreriE, TomatisM, SgambetterraS. Holy Shroud Exhibition 2010: health services during a 40-day mass-gathering event. Prehosp Disaster Med. 2013;28(3):1-6.
Food security and development in South Sudan: a call to action
Authors: Tappis Hannah , Doocy Shannon , Paul Amy , Funna Sonya 
Published: March 2013

AbstractObjectiveTo examine household food insecurity and coping mechanisms in two relatively politically stable states of South Sudan.DesignCross-sectional assessment including structured interviews and focus group discussions with food aid programme beneficiaries and staff. Structured interview findings were analysed with descriptive statistics using the statistical software package STATA version 11.SettingRural households in four payams (sub-county administrative districts) benefiting from a multi-year assistance programme funded by the US Agency for International Development. The study was conducted in January 2012, six months after independence.SubjectsStudy subjects included eighty mothers of children aged 6–23 months in structured interviews and eight focus groups, each with six to ten participants, of mothers of children aged 6–23 months.ResultsNinety-three per cent of households surveyed in Warrap and 100 % of households in Northern Bahr el Ghazal states were severely food access insecure. Nearly all households (97·5 %) surveyed in both states reported there were months in 2011 without enough food to eat. The majority of households (88 %) reported sometimes or often going to bed hungry in the month preceding the study. A number of coping mechanisms were used when households did not have enough food, including reduced meal size, skipping meals, selling assets and engaging in some kind business in order to generate money to buy food.ConclusionsGiven the highly volatile political, economic and humanitarian situation in South Sudan, the priorities of the international community are understandably focused on securing greater stability in South Sudan and preventing humanitarian needs from escalating significantly. There is a need, however, for simultaneous emphasis on food assistance and longer-term development strategies throughout South Sudan, particularly in areas of agriculture, livelihoods and food security.
GMC Origins and Turbulent Motions in Spiral and Dwarf Galaxies
Authors: Elmegreen Bruce G. 
Published: March 2013

AbstractCO clouds can be non-self-gravitating in high pressure environments, while most should be strongly self-gravitating at low metallicities and ambient pressures. In the LMC, which is HI-rich, GMC formation and destruction should generally include molecule formation and destruction. In M51, which is CO-rich, GMCs grow by coalescence. The Milky Way is between these two situations. In all cases, large clouds form by accretion of gas and smaller clouds independently of the presence of molecules. GMCs in the Milky Way are analogous to dust lanes and spurs in other galaxies. The virial parameter α usually decreases monotonically with increasing cloud mass in surveys, which implies that small scale structure is formed by turbulence. Hierarchies of sequences with decreasing α should be present in cloud complexes from sub-solar masses up to the ambient Jeans mass (107M⊙).
Deuterium Fractionation and Ionization Degree in Massive Protostellar/cluster Cores
Authors: Chen Huei-Ru , Liu Sheng-Yuan , Su Yu-Nung 
Published: March 2013

AbstractWe have conducted a survey of deuterium fractionation of N2H+, RD(N2H+) ≡ N(N2D+)/N(N2H+), with the Arizona Radio Observatory (ARO) Submillimeter Telescope (SMT) to assess the use of RD(N2H+) as an evolutionary tracer among massive protostellar/cluster cores in early stages. Our sample includes 32 dense cores in various evolutionary stages, from high-mass starless cores (HMSCs), high-mass protostellar objects (HMPOs), to ultra-compact (UC) HII regions, in infrared dark clouds (IRDCs) and high infrared extinction clouds. The results show a decreasing trend in deuterium fractionation with evolutionary stage traced by gas temperature and line width (Fig. 1). A moderate increasing trend of deuterium fractionation with the CO depletion factor is also found among cores in IRDCs and HMSCs. These suggest a general chemical behavior of deuterated species in low- and high-mass protostellar candidates. Upper limits to the ionization degree are also estimated to be in the range of 4 × 10−8 − 5 × 10−6.
Molecular Gas Around the Infrared Dust Bubbles
Authors: Gong Yan , Mao Ruiqing , Fang Min , Sun Jixian , Lu Dengrong 
Published: March 2013

AbstractWe have conducted a mapping survey toward a sample of 17 infrared dust bubbles in three 3 mm waveband CO isotopic lines simultaneously. Such bubbles are candidates to search for triggered massive star formation. We present the data and report preliminary results.
VLBI Observations and NH3 Mapping of the Star-forming Region NGC2264
Authors: Kamezaki Tatsuya , Imura Kenji , Nagayama Takumi , Omodaka Toshihiro , Handa Toshihiro , Yamaguchi Yoshiyuki , Chibueze James O. , Sunada Kazuyoshi , Nakano Makoto 
Published: March 2013

AbstractWe have measured the annual parallax of the water maser source associated with star forming region NGC2264 from observations with VLBI Exploration of Radio Astrometry (VERA). We detected masers at VLSR = 7.2 km s−1. We discussed its driving sources of detected maser spots. One of the maser spots was associated with a centimeter continuum source observed with VLA. Neither optical, infrared nor X-ray sources is catalogued near the spot. The other maser spot is located close to an X-ray source, although there is no optical or infrared counterpart. The proper motion of the former spot was (μα, μδ) = (23.91 ± 4.29, −29.81 ± 4.27) and the proper motion of latter spot was (μα, μδ) = (−0.96 ± 0.58, −6.05 ± 3.06). For the latter spot, the peculiar motion is ∼ 150 km s−1 and it has the high velocity and this may be a jet or an outflow from a young star. The observed parallax is 1.365 ± 0.098 mas, corresponding to the distance of 738+57−50 pc. This value is constant with the photometric distance of NGC2264 previously measured. The fitting result of the parallax is shown in figure 1. We also observed in NH3 (1,1), (2,2), (3,3) lines of NGC2264 with the Kashima 34m telescope. We estimated the star formation efficiency (SFE) of NGC2264 from the dense molecular mass of NH3 and the stellar mass calculated by Teixeira et al. (2012). The SFE is 9 – 12% which is consistent with previous results.
Molecular gas and triggered star formation surrounding Wolf-Rayet stars
Authors: Liu Tie , Wu Yuefang , Zhang Huawei 
Published: March 2013

AbstractThe environments surrounding nine Wolf-Rayet stars were studied in molecular emission. Expanding shells were detected surrounding these WR stars (see left panels of Figure 1). The average masses and radii of the molecular cores surrounding these WR stars anti-correlate with the WR stellar wind velocities (middle panels of Figure 1), indicating the WR stars has great impact on their environments. The number density of Young Stellar Objects (YSOs) is enhanced in the molecular shells at ∼5 arcmin from the central WR star (lower-right panel of Figure 1). Through detailed studies of the molecular shells and YSOs, we find strong evidences of triggered star formation in the fragmented molecular shells (Liu et al. 2010).
Evolution of HII Regions around Massive YSOs
Authors: Stephens Ian W. , Looney Leslie W. , Indebetouw Remy , Chu You-Hua , Gruendl Robert A. , Chen C.-H. Rosie , Seale Jonathan P. , Evans Jessica Marie 
Published: March 2013

AbstractWe survey HII free-free emission around ∼60 spectroscopically confirmed young stellar objects (YSOs) in the Large Magellanic Cloud using the Australia Telescope Compact Array (ATCA) at 3.3 and 5.5 cm. From each YSOs' infrared spectrum, we: a) quantify how embedded/evolved the YSO is through principle component analysis (PCA) of the silicate absorption (Seale et al. 2009); and b) estimate the mass from SED models (Robitaille et al. 2007). We have four main results: (1) Based on mass estimates from SED models and ATCA detection limits, we find that most massive YSOs are in HII regions regardless of age; (2) Older massive YSOs (as indicated by silicate PCA index) are much more likely to be resolved than younger YSOs, indicating evolving HII regions; (3) Resolved (typically older) sources usually have lower densities. Thus, in our survey we see a transition from ultra-compact HII to HII regions; and (4) We find that accretion about the massive YSO is likely non-spherical, resulting in HII regions in the shape of prolate spheroids.
AMANOGAWA-2SB survey: a northern galactic plane survey in 12CO (J = 2 − 1) and 13CO (J = 2 − 1) with the Amanogawa telescope
Authors: Handa Toshihiro , Yoda Takahiro , Kohno Kotaro , Nakajima Taku , Morino Jun-ichi , Yonekura Yoshinori , Ogawa Hideo , Kimura Kimihiro , Dobashi Kazuhiro 
Published: March 2013

AbstractWe performed 12CO(J = 2 − 1) and 13CO(J = 2 − 1) line surveys of the galactic plane using the AMANOGAWA telescope (Nakajima et al. 2007) which covers 5° ≤ l ≤ 180° on a 7'.5 grid. The telescope beamsize and velocity resolution are 8.7′ ± 0.4′ and 1.3 km s−1. The resultant rms noise level is typically 0.12 K in TA*. We found a linear correlation between 12CO(J = 2 − 1) and 12CO(J = 1 − 0) and a curved correlation between 12CO(J = 2 − 1) and 13CO (J = 2 − 1), although the intensity ratios of these three lines have intrinsic variation. These correlations can be reproduced with simple radiative transfer equations suggesting some restrictions on the physical quantities of molecular gas on a galactic scale.
The disk targets for LAMOST pilot survey
Authors: Hou J. L. , Zhong J. , Chen L. , Yu J. C. , Liu C. , Deng L. C. 
Published: March 2013

AbstractLAMOST has 4 meters in diameter with 4000 fibers in the focal plane. The telescope is now on the way towards full spectroscopy survey periods. This survey project has the potential to largely increase our understanding of the substructure of the Galactic stellar spheroid and different disk components through accurate measurements of radial velocities, metallicities and effective temperatures of millions of stars.
The spiral structure of our Milky Way
Authors: Hou L. G. , Han J. L. 
Published: March 2013

AbstractThe spiral structure of our Milky Way has not yet been well outlined. HII regions, giant molecular clouds (GMCs) and 6.7-GHz methanol masers are primary tracers for spiral arms. We collect and update the database of these tracers which has been used in Hou et al. (2009) for the spiral arms.The new database consists of ∼ 2000 HII regions, ∼ 1300 GMCs and ∼ 800 methanol masers (6.7 GHz). If the photometric or trigonometric distance for any tracer is available from the literature, we will adopt it. Otherwise, we have to use the kinematic distance. We modify the VLSR according to the newly determined solar motions (U0 = 10.27 km s−1, V0 = 15.32 km s−1 and W0 = 7.74 km s−1, Schönrich et al. 2010), then calculate the kinematic distances with a flat rotation curve (R0 = 8.3 kpc, θ0 = 239 km s−1, Brunthaler et al. 2011). Very important step is that we weight tracers according to the excitation parameters of HII regions or the masses of GMCs, and a constant weight for masers. All three kinds of tracers are used together to outline the spiral structure (Fig. 1). A contour and gray map is constructed after we made a Gaussian extension for the tracers with the amplitude of weighting parameter.
H2CO Observations Towards CH3OH Maser Sources
Authors: Okoh Daniel , Esimbek Jarken , Zhou JianJun , Tang Xindi , Chukwude Augustine , Urama Johnson , Okeke Pius 
Published: March 2013

AbstractFormaldehyde (H2CO) is an accurate probe of physical conditions in dense and low-temperature molecular clouds towards massive star formation regions, while 6.7 GHz methanol (CH3OH) masers provide ideal sites to probe the earliest stages of massive stellar formation. We present preliminary results of our investigation into the possible relationship between formaldehyde and methanol astrophysical masers with the view to expanding knowledge on massive star formation processes. Observations are done using the Nanshan 25m radio telescope of the Xinjiang Astronomical Observatories, Urumqi, China. 127 Methanol sources (from the work of Green et al. 2010, Xu et al. 2003, Pestalozzi et al. 2005, and Xu et al. 2009) have been observed so far for 4.8 GHz formaldehyde absorption lines, and H2CO signals have been detected in 86 of them, 31 of which are newly discovered. We obtained good correlation (0.85 correlation coefficient) between the velocities of the sources, and a poor correlation (−0.03 correlation coefficient) between their intensities, an indication that signals from the two lines originate from about the same region, but that the excitation mechanisms that drive them are likely different.
The ISM of Low Metallicity Galaxies: The Herschel view
Authors: Madden Suzanne C. , Rémy Aurélie , Galliano Frédéric , Galametz Maud , Bendo George , Cormier Diane , Lebouteiller Vianney , Hony Sacha ,   Herschel SAG 2 consortium
Published: March 2013

AbstractThe wide variety of low metallicity galaxies of the local universe serve as convenient laboratories to study the evolution of gas and dust and conditions for star formation in environments which may resemble those of the early universe. The Herschel Dwarf Galaxy Survey is studying the far infrared (FIR) and submillimeter (submm) properties of the gas and dust in galaxies with metallicity values as low as 1/45 that of solar. With complementary Spitzer, Laboca/APEX, Scuba/JCMT data, the dust spectral energy distributions are well constrained now, providing more accurate dust masses. We find a steep drop in dust-to-gas mass ratio (D/G) when the metallicity is below 12+log(O/H) ∼ 8. A submillimeter excess can be found in some low metallicity galaxies, which, when present, becomes apparent at wavelengths at or longer than 500 μm. While CO is difficult to observe in low metallicity gas, the FIR fine structure lines, on the other hand, are very luminous and highlight a potentially important reservoir of CO-free molecular gas, better traced by the 158 μm [CII] line.