bluuebunny/crossref_metadata_2025 huggingface dataset:
ARE AMERICA'S CIVIL RIGHTS LAWS STILL RELEVANT?
Authors: Skrentny John D.
Published: January 2008

The federal government created America's historic 1964 Civil Rights Act during a period of low immigration. The primary goal was to create equal opportunities for African Americans by ending Jim Crow discrimination in the South. Focusing on the issue of employment discrimination, and specifically employer preferences for immigrants, this article shows how the current period of high immigration from Latin America and Asia has created new challenges and dilemmas for Title VII, the employment discrimination title of the Civil Rights Act. Specifically, sociological evidence indicates that U.S. businesses are engaging in race-conscious employment focused on the perceived value ofracial skills(special abilities of certain racial groups at particular jobs) andracial symbolism(organizational benefits from displaying certain races on the work force). Businesses hire Asians and Latinos, and especially immigrant Asians and Latinos, because of the perceived racial skills of these groups at low-status jobs that require strong work ethics and obedient attitudes. Corporate employers seeking skilled workers do not necessarily prefer immigrants. Instead, they seek minorities for the symbolic value of their diversity, for their general racial skills at bringing new ideas to the workplace, and for their racial marketing skills for growing non-White markets. I assess these developments from a legal perspective, showing that a combination of a lack of litigation and some key court decisions have prevented Title VII from regulating racial skills and racial symbolism and/or from offering protection for immigrants themselves.
RECENT IMMIGRATION AND RACE
Authors: Vickerman Milton
Published: January 2008

Contemporary immigration is affecting U.S. society in many ways, particularly with respect to racial dynamics. Three aspects of these dynamics stand out: the conceptualization of race, the meaning of assimilation, and racial relations between groups. Although contemporary immigration, being largely non-White, is challenging U.S. society's entrenched conceptualization of race as revolving around a Black/White framework, this framework is not being rapidly overturned. Instead, immigrants are increasing social complexity by both adapting to the Black/White dichotomy and seeking alternatives to it through multiculturalism. The conceptualization ofraceis pivotally important because it determines the shape of assimilation, and, consistent with growing immigration-driven complexity, no one model of assimilation dominates the society. Instead, Anglo-conformity and multiculturalism are competing for preeminence. Blacks, because of U.S. society's failure to completely absorb them, helped to originate multiculturalism, but immigration is strengthening the model's appeal. Blacks and immigrants are adapting to U.S. society by utilizing both Anglo-conformity and multiculturalism. Immigration, increasingly, is also influencing race relations because of its volume and character. Even though Black/White conflict remains unresolved, future race relations will go beyond this nexus to incorporate other groups in complex interactions, revolving around the formation of coalitions and conflict situations as groups pursue particular interests.
WHO FIGHTS
Authors: Wong Cara
Published: January 2008

In discussions of political obligation, it is commonly assumed that duties follow from citizenship. However, the performance of a duty by aliens can lead to citizenship status in at least one critical case: service by noncitizen soldiers. While politicians and pundits recently have called citizenship a just reward for bearing arms and these “green card troops” another example of immigrant entrepreneurship in the United States, there is a good deal of ideological ambivalence about the policy. A clear discussion of its merits is crucial, particularly because in upending the traditionally accepted relationship between obligation and membership in a community, it gives new meaning to citizenship; it also forces a choice between our egalitarian and civic republican values. In this essay, I provide a theoretical framework for evaluating the policy normatively, as well as a political analysis of why—regardless of one's normative stance—the practice of granting citizenship for military service is likely to continue into the future.
A MAY TO REMEMBER
Authors: Ana Otto Santa , Treviño Sandra L. , Bailey Michael J. , Bodossian Kristen , de Necochea Antonio
Published: January 2008

We examine mainstream U.S. print news depictions of the 2006 immigration policy debate. Using critical discourse analysis informed by cognitive metaphor theory, we analyze a substantial sample of mainstream U.S. print news reports in May 2006, at the height of national attention on the “Great May Day” demonstrations across the country. We compare it to a second sample of print news media articles from October 2006, at the time of the passage of the 2006 Secure Fence Act. Mainstream print media represented immigrants with a noteworthy balance between human and nonhuman language during the time of the Great May Day marches. However, the media did not sustain a balanced representation of immigrants in the ensuing months. The conceptual metaphorimmigrant as criminalis predominant during both periods. We explore the implication of the language used to frame the immigration policy debate.
Tracing pumping routes in OH
Authors: Gray Malcolm D. , Howe D. A. , Lewis B. M.
Published: January 2008

We introduce a general method of restoring detailed information about the population flow in molecules under non-local-thermodynamic-equilibrium (NLTE) conditions. This information is usually discarded in numerical algorithms which generate only a solution. We apply the method to tracing the pumping schemes for OH in models that represent three common astrophysical maser environments: the envelopes of asymptotic-giant-branch (AGB) stars, the envelopes of red supergiants, and Galactic star-forming regions. In all three of these cases, we show that a large fraction, typically 0.8 or more, of the maser inversion can be recovered from a set of routes that depend on a much smaller fraction (considerably less than 0.1) of the total number of input coefficients to the model. Therefore, these cases display underlying simplicity in the pumping scheme.
Periodic variations in 6.7-GHz methanol masers
Authors: Goedhart Sharmila , Gaylard Michael J. , van der Walt D. Johan
Published: January 2008

An intensive monitoring program of 54 6.7-GHz methanol maser sources was carried out at the Hartebeesthoek Radio Astronomy Observatory from January 1999 to April 2003. The monitoring program was subsequently continued on 19 sources of interest. Analysis of the resulting time-series stretching over eight years shows that six of the sources are periodic, with periods ranging from 133 days to 504 days. The waveforms in individual sources range from sinusoidal fluctuations to sharp flares and there can be other long term trends in the time-series. The amplitudes of the variations can also change from cycle to cycle. The time-series of the periodic masers will be presented, and possible causes of the variability discussed.
The infrared environments of masers associated with star formation
Authors: De Buizer James
Published: January 2008

The near infrared (1–2μm) and the thermal infrared (3–25μm) trace many of the environments in which masers are thought to reside, including shocks, outflows, accretion disks, and the dense medium near protostars. After a number of recent surveys it has been found that there is a higher detection rate of mid-IR emission towards masers than cm radio continuum emission from UC HII regions, and that the mid-IR emission is actually more closely cospatial to the maser locations. A high percentage of water and methanol masers that are not coincident with the UC HII regions in massive star forming regions are likely to be tracing outflows and extremely young high mass stars before the onset of the UC HII region phase. After a decade of groundwork supporting the hypothesis that linearly distributed class II methanol masers may generally trace accretion disks around young massive stars, compelling evidence is mounting that these masers may generally be associated with outflows instead. Substantiation of this claim comes from recent outflow surveys and high angular resolution mid-IR imaging of the maser environments.
A review of H2CO 6cm masers in the Galaxy
Authors: Araya E. , Hofner P. , Goss W. M.
Published: January 2008

We present a review of the field of formaldehyde (H2CO) 6cm masers in the Galaxy. Previous to our ongoing work, H2CO 6cm masers had been detected in the Galaxy only toward three regions: NGC7538 IRS1, Sgr B2, and G29.96–0.02. Current efforts by our group using the Very Large Array, Arecibo, and the Green Bank Telescope have resulted in the detection of four new H2CO 6cm maser regions. We discuss the characteristics of the known H2CO masers and the association of H2CO 6cm masers with very young regions of massive star formation. We also review the current ideas on the pumping mechanism for H2CO 6cm masers.
Water masers within the G 333.2–0.6 giant molecular cloud
Authors: Breen S. L. , Ellingsen S. P. , Johnston-Hollitt M. , Wotherspoon S. , Bains I. , Burton M. G. , Cunningham M. , Lo N. , Senkbeil C. E. , Wong T.
Published: January 2008

We report the results of a blind search for 22 GHz water masers in two regions, covering approximately half a square degree, within the G 333.2–0.6 giant molecular cloud. The complete search of the two regions was carried out with the 26 m Mount Pleasant radio telescope and resulted in the detection of nine water masers, five of which are new detections. Australia Telescope Compact Array (ATCA) observations of these detections have allowed us to obtain positions with arcsecond accuracy, allowing meaningful comparison with infrared and molecular data for the region. We find that for the regions surveyed there are more water masers than either 6.7 GHz methanol, or main-line OH masers. The water masers are concentrated towards the central axis of the star formation region, in contrast to the 6.7 GHz methanol masers which tend to be located near the periphery. The colours of the GLIMPSE point sources associated with the water masers are slightly less red than those associated with methanol masers. Statistical investigation of the properties of the 13CO and 1.2 mm dust clumps with and without associated water masers shows that the water masers are associated with the more massive, denser and brighter 13CO and 1.2 mm dust clumps. We present statistical models that can predict those 13CO and 1.2 mm dust clumps likely to have associated water masers.
Tick tock – the 12.2 GHz methanol masers in G9.62+0.20
Authors: Gaylard Michael J. , Goedhart Sharmila
Published: January 2008

The bright interstellar methanol masers at 12.2 GHz and 6.7 GHz were discovered in 1987 and 1991 respectively. It was soon established that many were quite variable. Goedhart Gaylard & van der Walt (2003) reported that one source, G9.62+0.20E, exhibited flares at 12.2 and 6.7 GHz that appeared to be periodic, repeating every 246 days. Since then, monitoring of this and other possibly periodic sources has continued with the 26-m Hartebeesthoek telescope. We discuss here the full 12.2 GHz time series data of G9.62+0.20 through 2006. The data quality has been much improved by telescope upgrades. Flares in the main maser peak continue, the repetition rate remains close to that originally determined.
Discovery of polarized 6.7-GHz methanol masers in DR21/W75
Authors: Harvey-Smith L. , Soria-Ruiz R. , Duarte-Cabral A. , Cohen R. J.
Published: January 2008

We present the first images of 6.7 GHz methanol masers in the DR21 star-forming complex. We have discovered two sites of Class II methanol maser emission; in DR21(OH) and DR21(OH)N. The emission comprises clusters of linearly extended masers which have velocity gradients along their length. There are four maser spots in DR21(OH)N, some of which show a small fraction of linear polarization. The twelve masers in DR21(OH) lie in a linear arrangement stretching approximately 0.7 arcseconds and show no significant linear polarization. We were not able to detect any circular polarization in the masers.
Astrometry of H2O maser sources in nearby molecular clouds with VERA
Authors: Hirota Tomoya , Bushimata Takeshi , Choi Yoon Kyung , Honma Mareki , Imai Hiroshi , Iwadate Kenzaburo , Jike Takaaki , Kameno Seiji , Kameya Osamu , Kamohara Ryuichi , Kan-ya Yukitoshi , Kawaguchi Noriyuki , Kijima Masachika , Kim Mi Kyoung , Kobayashi Hideyuki , Kuji Seisuke , Kurayama Tomoharu , Manabe Seiji , Maruyama Kenta , Matsui Makoto , Matsumoto Naoko , Miyaji Takeshi , Nagayama Takumi , Nakagawa Akiharu , Nakamura Kayoko , Oh Chung Sik , Omodaka Toshihiro , Oyama Tomoaki , Sakai Satoshi , Sasao Tetsuo , Sato Katsuhisa , Sato Mayumi , Shibata Katsunori M. , Shintani Motonobu , Tamura Yoshiaki , Tsushima Miyuki , Yamashita Kazuyoshi
Published: January 2008

We have carried out multi-epoch VLBI observations of the H2O maser sources associated with young stellar objects (YSOs) in nearby molecular clouds with VERA (VLBI Exploration of Radio Astrometry), which is a newly constructed VLBI network in Japan (Kobayashiet al. 2003). The main goal of our study is to measure the absolute proper motions and distances to nearby molecular clouds within 1 kpc from the Sun, to reveal their 3-dimensional structures and dynamical properties. Using the VERA dual-beam receiving system (Honmaet al. 2003), we have carried out phase-referencing VLBI observations and measured annual parallaxes and absolute proper motions of the H2O maser features with respect to the extragalactic radio sources. We have successfully detected the annual parallax of one of the H2O maser features in Orion KL to be 2.29±0.10 mas, corresponding to the distance of 437±19 pc from the Sun (Hirotaet al. 2007). In addition, the annual parallax of SVS13 in NGC 1333 is also determined to be4.10±0.17 mas, corresponding to the distance of 244±10 pc from the Sun, although the life time of the maser features are only 6 months. The absolute proper motions of the H2O maser features associated with Orion KL and NGC 1333 are derived, possibly indicating the outflow motions from the YSOs as well as the systemic motions of the powering sources.
The 44 GHz methanol maser line in massive star forming regions
Authors: Hofner P. , Jordan E. , Araya E. , Kurtz S.
Published: January 2008

We present the results of recent surveys in the 44GHz methanol maser line toward regions of massive star formation using the Haystack 37m telescope and the VLA. We discuss a possible shock origin of this maser line and present evidence for variability from multi-epoch observations of selected sources.
A precise distance to IRAS 00420+5530 via H2O maser parallax with the VLBA
Authors: Moellenbrock G. A. , Claussen M. J. , Goss W. M.
Published: January 2008

We have used the VLBA to measure the annual parallax of the H2O masers in the star-forming region IRAS 00420+5530 (l=122.0°, b= -7.1°). This measurement yields a direct distance estimate of 2.17±0.05kpc, which disagrees substantially with most other published estimates (a range from 1.7 to 7.7kpc). This distance is consistent with recent parallax-based distances reported for W3(OH) (Xu et al. 2006, Hachisuka et al. 2006), lending additional support to the conclusion that the Perseus Spiral Arm of the Milky Way is a factor of at least two closer than kinematic distance estimates imply at galactic longitude ~130 degrees.
Absolute proper motions of water masers in NGC 281 measured with VERA
Authors: Sato Mayumi , Hirota Tomoya , Honma Mareki , Kobayashi Hideyuki ,   VERA Project Team
Published: January 2008

We report on absolute proper-motion measurements of H2O maser features in the NGC 281 West molecular cloud, located ~320 pc above the Galactic plane and associated with an HI loop extending from the Galactic plane. We conducted six-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over six months since May 2006. The H2O maser features are found to be systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of ~20–30 km s−1 at its estimated distance of 2.2–3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.
Japanese VLBI network observations of 6.7-GHz methanol masers II. Results
Authors: Sugiyama Koichiro , Fujisawa Kenta , Honma Mareki , Doi Akihiro , Mochizuki Nanako , Murata Yasuhiro , Isono Yasuko
Published: January 2008

We are using a Japanese VLBI network (JVN) for VLBI observations of 6.7-GHz methanol masers associated with massive star-forming regions. Here we present results for Cepheus A (Cep A) from observations taken on September 9, 2006. The distribution of the maser spots indicates either a spherical bubble or a disk having an inclination of several tens degree. We construct a disk model with an inclination of ~70° and a radius of ~700 AU. From a luminosity of 1.7 × 104L⊙for a source observed in this region, the excitation of the maser is probably radiative.
Where methanol masers spring
Authors: Torstensson Karl J. E. , van Langevelde Huib Jan , Bourke Stephen
Published: January 2008

We are carrying out a program to observe the 6.7 GHz methanol maser emission in high-mass star-forming regions using large FOV (~2'), astrometric, VLBI data. Here we report on the first results of the inner few arc seconds in Cepheus A East. We find a maser filament extending over ~1.7” (1200 AU), straddling the waist of Cep A HW2. The region in which the CH3OH masers are found contains several YSO's and it is not clear whether the CH3OH masers are associated with several different objects or rather the larger scale surrounding environment.
Water maser and radio continuum emission towards IRAS 23139+5939
Authors: Trinidad M. A. , Curiel S. , Torrelles J. M. , Rodríguez L. F. , Migenes V. , Patel N.
Published: January 2008

We present simultaneous observations of continuum (3.5 and 1.3cm) and water maser line emission (1.3cm) carried out with the VLA-A toward the high-mass object IRAS 23139+5939. We detected two radio continuum sources at 3.5cm separated by 0”5 (~2400 AU), I23139 and I23139S. Based on the observed continuum flux density and the spectral index, we suggest that I23139 is a thermal radio jet associated with a high-mass YSO. On the other hand, based on the spatio-kinematical distribution of the water masers, together with the continuum emission information, we speculate that I23139S is also a jet source powering some of the masers detected in the region.
Imaging of selected sources from the Methanol Multibeam Survey
Authors: Wong-McSweeney D. , Fuller G. A. , Etoka S.
Published: January 2008

High angular resolution observations are essential for understanding the nature of maser emission and the sources which excite it. Here we present preliminary results from MERLIN observations of three methanol masers from the Toruń survey. These MERLIN observations are being analysed as part of the interferometric component of the Methanol Multibeam (MMB) Survey which is surveying the Galactic plane at |b|≤2° for 6.67 GHz methanol maser sources.
The Arecibo Methanol Maser Galactic Plane Survey
Authors: Pandian Jagadheep D. , Goldsmith Paul. F. , Deshpande Avinash A.
Published: January 2008

The Arecibo Methanol Maser Galactic Plane Survey (AMGPS) is a blind survey for 6.7 GHz methanol masers in a section of the Galactic plane visible from the Arecibo radio telescope. The survey for these signposts of massive star formation is complete at a flux density level of 0.27 Jy making it the most sensitive blind survey for methanol masers carried out to date, and resulted in the detection of 86 methanol masers, 48 of which are new discoveries. The properties of methanol masers discovered in the survey are consistent with their being associated with early phases of massive star formation. The data also show the tangent point of the Carina-Sagittarius spiral arm to be around a Galactic longitude of 49.6°.
The Methanol Multibeam Survey
Authors: Green James A. , Cohen R. J. , Caswell J. L. , Fuller G. A. , Brooks K. , Burton M. G. , Chrysostomou A. , Diamond P. J. , Ellingsen S. P. , Gray M. D. , Hoare M. G. , Masheder M. R. W. , McClure-Griffiths N. , Pestalozzi M. , Phillips C. , Quinn L. , Thompson M. A. , Voronkov M. , Walsh A. , Ward-Thompson D. , Wong-McSweeney D. , Yates J. A. , Cox J.
Published: January 2008

A new 7-beam methanol multibeam receiver is being used to survey the Galaxy for newly forming massive stars, that are pinpointed by strong methanol maser emission at 6.668 GHz. The receiver, jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF), was successfully commissioned at Parkes in January 2006. The Parkes-Jodrell survey of the Milky Way for methanol masers is two orders of magnitude faster than previous systematic surveys using 30-m class dishes, and is the first systematic survey of the entire Galactic plane. The first 53 days of observations with the Parkes telescope have yielded 518 methanol sources, of which 218 are new discoveries. We present the survey methodology as well as preliminary results and analysis.
The 3D morphology of the ejecta surrounding VY Canis Majoris
Authors: Jones Terry Jay , Humphreys Roberta M. , Helton L. Andrew
Published: January 2008

We use second epoch images taken with WFPC2 on the HST and imaging polarimetry taken with the HST/ACS/HRC to explore the three dimensional structure of the circumstellar dust distribution around the red supergiant VY Canis Majoris. Transverse motions, combined with radial velocities, provide a picture of the kinematics of the ejecta, including the total space motions. The fractional polarization and photometric colors provide an independent method of locating the physical position of the dust along the line-of-sight. Most of the individual arc-like features and clumps seen in the intensity image are also features in the fractional polarization map, and must be distinct geometric objects. The location of these features in the ejecta of VY CMa using kinematics and polarimetry agree well with each other, and strongly suggest they are the result of relatively massive ejections, probably associated with magnetic fields.
Variability of masers in circumstellar shells on timescales of decades
Authors: Engels D. , Winnberg A. , Brand J. , Jiménez-Esteban F.
Published: January 2008

Based on a 15–20 year long monitoring program of H2O masers and new observations of OH masers discovered 35 years ago, we studied the variability of maser emission in AGB stars over timescales of decades. The H2O maser features in the semi-regular variable stars RX Boo and SV Peg, and of the Mira stars U Her and R Cas, showed strong fluctuations superposed in case of the Mira stars on regular variations due to the pulsation of the stars. The spatial distribution of the emission regions in RX Boo and U Her showed deviations from spherical symmetry, which remained unchanged over >10 years. We conclude that the spatial asymmetry is determined by the underlying asymmetry of the mass loss process. There is no evidence that mass loss rates or the wind geometry in these stars have varied over the last 20 years. In 2005 we re-detected at 1612 MHz the 114 OH/IR stars discovered before 1978, implying an OH maser lifetime of >2800 years (1σ).
Infrared OH absorption lines in 1612 MHz OH maser sources
Authors: He J. H. , Chen P. S. , Szczerba R. , Sobolev A. M.
Published: January 2008

ISO mid-infrared absorption data helps to distinguish between radiative and collisional pumping mechanisms in 1612 MHz OH masers in various environments. Archive data of OH absorption at 34.6 and 53.3μm shows different behavior and different pumping rates for different types of maser sources.
Maser emission towards the young planetary nebula IRAS 17347-3139
Authors: Tafoya D. , Gómez Y. , Gómez J. F. , de Gregorio-Monsalvo I. , Uscanga L. , Anglada G. , Torelles J. M.
Published: January 2008

We have re-analyzed observations of the water maser emission in IRAS 17347-3139 carried out previously and compared them with new higher angular resolution and more sensitive radio-continuum observations to explain the shift between the position of the peak of the radio-continuum with respect to the center of the ring-like distribution. From our analysis, we found that the water maser emission is not distributed in a closed ring-like structure, but in what appears to be a segment of an ellipse centered in the position of the peak of the radio-continuum. These results can explain the shift between the radio-continuum and the water maser emission. We also present interferometric observations of the OH maser emission towards IRAS 17347-3139 from which we have found that the OH maser emission detected previously is not associated with this source. Furthermore, since our observations are more sensitive, we have detected for the first time weak OH maser emission associated with IRAS 17347-3139.
VLBA H2O and SiO maser observations in the pPN OH 231.8+4.2
Authors: Desmurs J.-F. , Contreras C. Sánchez , Bujarrabal V. , Alcolea J. , Colomer F.
Published: January 2008

We report high-resolution observations of H2O, 61,6−52,3 and 28SiO v=2, J=1-0 maser emissions obtained with the Very Long Baseline Array in the bipolar pre-planetary nebulae OH 231.8+4.2 (see Desmurs et al., 2007). A phase referencing technique was used to recover the absolute position of both emissions. We detected two groups of water vapour emission oriented nearly north-south. SiO masers are tentatively found to be placed between the two H2O maser emitting regions.
A collimated jet and an infalling-rotating disk in G192 traced by H2O maser emission
Authors: Imai Hiroshi , Omodaka Toshihiro , Hirota Tomoya , Umemoto Tomofumi , Sorai Kazuo , Kondo Tetsuro ,   the VERA collaboration
Published: January 2008

We present H2O masers associated with the massive-star forming region G192 observed with the Japan VLBI network since the year 2005, The spatio-kinematical structure of the maser feature clusters has well persisted since previous observations, in which the masers are associated with two young stellar objects (YSOs) separated by ~1200 AU and expected to be associated with a highly-collimated bipolar jet and an infalling-rotating disk in the northern and southern YSOs, respectively. We estimated a jet speed of ~100 km s−1 and re-estimated a dynamical age of the whole jet to be 5.6×104 years. The spatial distribution of maser Doppler velocities found during the previous and present observations, relative proper motions of H2O maser features in the southern cluster found in the present observations, a relative bulk motion between the two maser clusters are well explained by a model of an infalling-rotating disk with a radius of ~1000 AU and a central stellar mass of ~8 M⊙.
Improving the parallaxes of OH bearing Miras
Authors: Vlemmings W. H. T. , van Langevelde H. J.
Published: January 2008

We have carried out observations with the Very Long Baseline Array (VLBA) to measure the parallaxes of Mira variables and are able to improve the distance estimates significantly for a fraction of our sample (U Her, S CrB and RR Aql). This is predominantly because we have enhanced our technique by making use of nearby, in-beam calibrators. Additionally, the observing conditions have improved during the current solar minimum. The distances of these stars are of fundamental importance for studying the physical properties of Asymptotic Giant Branch (AGB) stars with high mass loss.
Discrete survey of 5-cm OH emission from planetary and proto-planetary nebulae
Authors: Desmurs J.-F. , Baudry A. , Sivagnanam P. , Henkel C. , Richards A. M. S.
Published: January 2008

We have undertaken a comprehensive search for the first excited state of OH emission (J=5/2, 2Π3/2) in Planetary and Proto- Planetary Nebulae. With the Effelsberg telescope, we confirm the detection of Vy 2–2 and we present one new detection in the pPN K3−35. This detection has been confirmed by subsequent observations made at 6035 MHz with the MERLIN interferometer. This is the first detection of 6 GHz OH maser emission from a post-AGB star.
Measurements of annual parallaxes and proper motions of the red supergiant S Per
Authors: Asaki Yoshiharu , Deguchi Shuji , Imai Hirishi , Hachisuka Kazuya , Miyoshi Makoto , Honma Mareki
Published: January 2008

VLBI phase-referencing monitoring of water vapor masers around the red supergiant, S Per, was conducted over four years. We successfully obtained proper motions and an annual parallax of the masers and determined the distance to S Per of 2.51±0.09 kpc. The proper motion of the star itself was inferred from the maser proper motions, and it was −0.38 and −1.54 mas/yr for right ascension and declination, respectively. Assuming the distance from the sun to the Galactic center, R0, of 8.5 kpc and the rotation velocity around the sun, Θ0, of 220 km/s, the Galactic rotation velocity around S Per is 200 km/s.
Positional coincidence between an H2O maser and a plasma torus in NGC 1052
Authors: Sawada-Satoh S. , Kameno S. , Nakamura K. , Namikawa D. , Shibata K. M. , Inoue M.
Published: January 2008

We present VLBA observation towards the nucleus of a nearby radio galaxy NGC 1052. In NGC 1052, two-sided jet structure and a dense plasma circumnuclear torus with a radius of 0.7 pc have been found around the central mass. It emits a H2O megamaser, which is redshifted with respect to the systemic velocity of the galaxy (1491 kms−1) with a large velocity width of 100 kms−1 (FWHM). The maser gas is found at the inner jet components of both the approaching and receding jets. The maser gas is positionally coincident with a plasma torus. The maser gas in NGC 1052 could be explained as a circumnuclear torus or disk, as found for the nucleus of NGC 4258.
The nuclear environment of the water megamaser radiogalaxy 3C 403
Authors: Tarchi Andrea , Brunthaler A. , Henkel C. , Menten K. M. , Braatz J. A. , Weiss A.
Published: January 2008

So far, few direct sub-arcsecond resolution studies exist of the dense material that, according to the standard unified scheme, should obscure the central engines of radio galaxies. In the following, observations are presented that highlight the nuclear environment of the prototypical X-shaped FR II galaxy 3C 403. To date, it is the only powerful radio galaxy known to host a water megamaser.
OH emission and absorption associated with supernovae in Arp 220
Authors: Lonsdale Colin J. , de Kleer Katherine R. , Diamond Philip J. , Thrall Hannah , Lonsdale Carol J. , Smith Harding E.
Published: January 2008

We present parsec-resolution spectral-line VLBI data for two epochs separated by 15 months as a precise new probe of the innermost regions of the nearby Ultraluminous Infrared Galaxy (ULIRG) Arp 220. This galaxy hosts a powerful starburst, with an associated supernova (SN) rate of order 4/yr. An extensive population of compact continuum sources interpreted as radio supernovae (RSNe) and young supernova remnants (SNR) has been imaged. We show here that many of the supernova-related radio continuum point sources exhibit clear evidence of OH absorption or maser emission in the intervening gas, and as such provide us with a sampling of conditions along very narrow and specific lines of sight through the nuclear environment. The OH gas along these lines of sight exhibits velocity dispersions of up to several tens of km/sec, and that in some cases, multiple distinct concentrations of masing gas at different radial velocities can be discerned. There is evidence for variability in the OH properties on ~1yr timescales. Our results are discussed in the context of the overall OH megamaser properties of Arp 220.
Arp 220 – IC 4553/4: understanding the system and diagnosing the ISM
Authors: Baan W. A.
Published: January 2008

Arp 220 is a nearby system in final stages of galaxy merger with powerful ongoing star-formation at and surrounding the two nuclei. Arp 220 was detected in HI absorption and OH Megamaser emission and later recognized as the nearest ultra-luminous infrared galaxy also showing powerful molecular and X-ray emissions. In this paper we review the available radio and mm-wave observational data of Arp 220 in order to obtain an integrated picture of the dense interstellar medium that forms the location of the powerful star-formation at the two nuclei.
The irradiated ISM of ULIRGs
Authors: Spaans M. , Meijerink R. , Israel F. P. , Loenen A. F. , Baan W. A.
Published: January 2008

The nuclei of ULIRGs harbor massive young stars, an accreting central black hole, or both. Results are presented for molecular gas that is exposed to X-rays (1–100 keV, XDRs) and far-ultraviolet radiation (6–13.6 eV, PDRs). Attention is paid to species like HCO+, HCN, HNC, OH, H2O and CO. Line ratios of HCN/HCO+ and HNC/HCN discriminate between PDRs and XDRs. Very high J (>10) CO lines, observable with HIFI/Herschel, discriminate very well between XDRs and PDRs. In XDRs, it is easy to produce large abundances of warm (T > 100 k) H2O and OH. In PDRs, only OH is produced similarly well.
658 GHz vibrationally-excited water masers with the Submillimeter Array
Authors: Hunter T. R. , Young K. H. , Christensen R. D. , Gurwell M. A.
Published: January 2008

Discovered in 1995 at the Caltech Submillimeter Observatory (CSO), the vibrationally-excited water maser line at 658 GHz (455 micron) is seen in oxygen-rich giant and supergiant stars. Because this maser can be so strong (up to thousands of Janskys), it was very helpful during the commissioning phase of the highest frequency band (620-700 GHz) of the Submillimeter Array (SMA) interferometer. From late 2002 to early 2006, brief attempts were made to search for emission from additional sources beyond the original CSO survey. These efforts have expanded the source count from 10 to 16. The maser emission appears to be quite compact spatially, as expected from theoretical considerations; thus these objects can potentially be used as atmospheric phase calibrators. Many of these objects also exhibit maser emission in the vibrationally-excited SiO maser at 215 GHz. Because both maser lines likely originate from a similar physical region, these objects can be used to test techniques of phase transfer calibration between millimeter and submillimeter bands. The 658 GHz masers will be important beacons to assess the performance of the Atacama Large Millimeter Array (ALMA) in this challenging high-frequency band.
The next generation space VLBI project, VSOP-2
Authors: Murata Yasuhiro , Mochizuki Nanako , Saito Hirofumi , Hirabayashi Hisashi , Inoue Makoto , Kobayashi Hideyuki , Edwards Philip G. ,   the Next Generation Space VLBI Working Group
Published: January 2008

The first dedicated space-VLBI project, the VLBI Space Observatory Programme (VSOP), commenced with the successful launch of radio-astronomical satellite HALCA in 1997. Plans for a second generation space-VLBI project have been made by a working group over a number of years. This project, VSOP-2, has now been approved by Japan's space agency, JAXA, as the ASTRO-G project. It is planned for the spacecraft to observe in the 8, 22 and 43 GHz bands with cooled receivers for the two higher bands, which include important maser lines. It will have a maximum angular resolution at 43 GHz (7 mm) of about 40 micro-arcseconds. Although the VSOP project mainly observed continuum emission from active galactic nuclei (AGN), VSOP-2/ASTRO-G is expected to enable a variety of high angular resolution maser line observations.
Ionogram‐recorded equatorial spread‐F and height changes at Huancayo during sunspot‐maximum years
Authors: Bowman G. G. , Mortimer I. K.
Published: January 2008

The analyses presented here consider equatorial nighttime disturbance conditions as indicated by spread‐F traces on ionograms, which record the presence of medium‐scale structures (MSSs) created by the passage of atmospheric gravity waves. Relationships between these MSSs and geomagnetic activity (GA) have been examined statistically, particularly considering the ionospheric height (h′F) changes (increases and decreases) associated with the presence or absence of these MSSs. It is shown that for the postsunset height increases with spread‐F present, the GA a few hours earlier has well‐defined low levels. In contrast, if these height increases are not accompanied by spread‐F, the GA a few hours earlier is high. When there are no height rises, similar inverse associations with GA are recorded for both (1) spread‐F present and (2) spread‐F absent. For the postsunset height decreases, when no spread‐F occurs, high GA levels are well defined at times about 7 h earlier. Thus all these results indicate an inverse relationship between the MSSs and GA. The experimental evidence suggests that the presunrise height rises are produced by large‐scale traveling ionospheric disturbances generated in auroral‐zone regions by substorm onsets.
Infiltration into fractured bedrock
Authors: Salve Rohit , Ghezzehei Teamrat A. , Jones Robert
Published: January 2008

One potential consequence of global climate change and rapid changes in land use is an increased risk of flooding. Proper understanding of floodwater infiltration thus becomes a crucial component of our preparedness to meet the environmental challenges of projected climate change. In this paper, we present the results of a long‐term infiltration experiment performed on fractured ash flow tuff. Water was released from a 3 × 4 m2 infiltration plot (divided into 12 square subplots) with a head of ∼0.04 m, over a period of ∼800 days. This experiment revealed peculiar infiltration patterns not amenable to current infiltration models, which were originally developed for infiltration into soils over a short duration. In particular, we observed that in part of the infiltration plot, the infiltration rate abruptly increased a few weeks into the infiltration tests. We suggest that these anomalies result from increases in fracture permeability during infiltration, which may be caused by swelling of clay fillings and/or erosion of infill debris. Interaction of the infiltration water with subsurface natural cavities (lithophysal cavities) could also contribute to such anomalies. This paper provides a conceptual model that partly describes the observed infiltration patterns in fractured rock and highlights some of the pitfalls associated with direct extension of soil infiltration models to fractured rock over a long period.
Modification of Ca isotope and trace metal composition of the major matrices involved in shell formation of Mytilus edulis
Authors: Heinemann Agnes , Fietzke Jan , Eisenhauer Anton , Zumholz Karsten
Published: January 2008

In this study we present the first combined investigation into the composition of the major matrices involved in calcification processes (surrounding water, extrapallial fluid, aragonite, and calcite) of Mytilus edulis with respect to their calcium isotope (δ44/40Ca) and elemental compositions (Sr/Ca and Mg/Ca). Our aim was to examine the suitability of Mytilus edulis as a proxy archive and to contribute to the understanding of the process of biomineralization. Mytilus edulis specimens were live collected from the Schwentine Estuary, Kiel Fjord, and North Sea (Sylt). δ44/40Ca was determined by thermal ionization mass spectrometry (TIMS) accompanied by measurements of Mg/Ca and Sr/Ca using inductively coupled plasma–optical emission spectroscopy (ICP‐OES). The elemental and isotopic compositions of the investigated matrices showed systematic offsets. The carbonates are strongly depleted in their magnesium and strontium concentrations and fractionated toward lighter calcium isotope compositions relative to the surrounding Schwentine Estuary water. The opposite is observed for the extrapallial fluid (EPF). Our findings extend the results of previous studies reporting a strong biological control and the interaction of different environmental conditions influencing biomineralization. Future studies should focus on the temporal development of the interrelation between the different matrices.
Sea level rise projections for current generation CGCMs based on the semi‐empirical method
Authors: Horton Radley , Herweijer Celine , Rosenzweig Cynthia , Liu Jiping , Gornitz Vivien , Ruane Alex C.
Published: January 2008

The semi‐empirical relationship between global surface air temperature and mean sea level first developed by Rahmstorf is here applied to the latest generation of Coupled Global Climate Models (CGCMs) used for the IPCC Fourth Assessment Report (AR4). Our results produce a broader range of sea level rise projections, especially at the higher end, than outlined in IPCC AR4. The range of sea level rise results is CGCM and emissions‐scenario dependent, and not sensitive to initial conditions or how the data are filtered temporally. Both the IPCC AR4 and the semi‐empirical sea level rise projections described here are likely to underestimate future sea level rise if recent trends in the polar regions accelerate.
Spatial distribution of isoprene emissions from North America derived from formaldehyde column measurements by the OMI satellite sensor
Authors: Millet Dylan B. , Jacob Daniel J. , Boersma K. Folkert , Fu Tzung‐May , Kurosu Thomas P. , Chance Kelly , Heald Colette L. , Guenther Alex
Published: January 2008

Space‐borne formaldehyde (HCHO) column measurements from the Ozone Monitoring Instrument (OMI), with 13 × 24 km2 nadir footprint and daily global coverage, provide new constraints on the spatial distribution of biogenic isoprene emission from North America. OMI HCHO columns for June‐August 2006 are consistent with measurements from the earlier GOME satellite sensor (1996–2001) but OMI is 2–14% lower. The spatial distribution of OMI HCHO columns follows that of isoprene emission; anthropogenic hydrocarbon emissions are undetectable except in Houston. We develop updated relationships between HCHO columns and isoprene emission from a chemical transport model (GEOS‐Chem), and use these to infer top‐down constraints on isoprene emissions from the OMI data. We compare the OMI‐derived emissions to a state‐of‐science bottom‐up isoprene emission inventory (MEGAN) driven by two land cover databases, and use the results to optimize the MEGAN emission factors (EFs) for broadleaf trees (the main isoprene source). The OMI‐derived isoprene emissions in North America (June–August 2006) with 1° × 1° resolution are spatially consistent with MEGAN (R2 = 0.48–0.68) but are lower (by 4–25% on average). MEGAN overestimates emissions in the Ozarks and the Upper South. A better fit to OMI (R2 = 0.73) is obtained in MEGAN by using a uniform isoprene EF from broadleaf trees rather than variable EFs. Thus MEGAN may overestimate emissions in areas where it specifies particularly high EFs. Within‐canopy isoprene oxidation may also lead to significant differences between the effective isoprene emission to the atmosphere seen by OMI and the actual isoprene emission determined by MEGAN.
Map‐based inventory of wetland biomass and net primary production in western Siberia
Authors: Peregon Anna , Maksyutov Shamil , Kosykh Natalya P. , Mironycheva‐Tokareva Nina P.
Published: January 2008

We used available field survey and literature data to produce inventory maps of wetland biomass and net primary production (NPP) for western Siberia. Field survey data were obtained for major types of wetland microlandscapes within the boreal (taiga) region. We developed a multiscale approach based on using a regional wetland typology map (1:2,500,000 scale), further refined by satellite image classifications (LANDSAT‐7, SPOT, RESURS, 1:200,000 scale). Satellite images on test areas designated in the boreal region of western Siberia were classified by 30 landscape classes. We used aerial photography (1:25,000 scale) to evaluate the fraction of the area occupied by microlandscape elements within patterned wetlands. As a result, we were able to produce a GIS map‐based inventory of ecosystem phytomass and NPP in west Siberian wetlands. Using the GIS map, the average and total net primary production and biomass were estimated by ecosystem type, the number of vegetation layers, and climatic gradient. The annual NPP to live biomass ratio increases southward from 0.27 in the tundra to 0.65 in the steppe region. Live biomass of wetlands amounts to only 10–30% of the average biomass of upland forests in the same climatic region, although wetland NPP was found to be equal or higher then that of upland forests. Mosses and the belowground fraction of grasses are the major contributors to NPP. Average live biomass and NPP in wetlands were estimated to be 1600 g/m2 and 790 g/m2/yr, respectively. Total wetland NPP amounts to 530 Tg/yr, and live biomass amounts to 1070 Tg.
Analysis of periodic shielded microstrip lines excited by nonperiodic sources through the array scanning method
Authors: Valerio G. , Baccarelli P. , Burghignoli P. , Galli A. , Rodríguez‐Berral R. , Mesa F.
Published: January 2008

In this paper we aim at rigorously studying the practical excitation of a shielded microstrip line periodically perturbed by gaps. In particular a delta‐gap voltage source is considered in an environment shielded by lateral and top metallic walls. The excitation problem is solved through a numerical implementation of the array scanning method, in which the field excited by a nonperiodic source in a periodic environment is represented as an integral superposition of fields, which are solutions of suitable auxiliary Floquet‐periodic problems. To solve the latter, a spectral‐domain method‐of‐moments approach has been adopted, introducing original acceleration techniques to enhance the efficiency and accuracy of the method. The numerical performance of the spectral‐domain approach is illustrated and fully validated. Results are presented both for the dispersive properties of Bloch modes supported by the structure in the absence of excitation and for the currents excited on the structure by a single delta‐gap source, also discussing the modal representation of such currents in terms of Green's function singularities in the spectral plane of the longitudinal wavenumber.
Obesity and Inpatient Rehabilitation Outcomes Following Knee Arthroplasty: A Multicenter Study
Authors: Vincent Heather K. , Vincent Kevin R.
Published: January 2008

Objective: This multicenter study examined whether inpatient rehabilitation outcomes following total knee arthroplasty (TKA) were influenced by BMI.

Methods and Procedures: This was a retrospective, comparative study conducted using a computerized medical database and medical records derived from TKA patients, at 15 independent rehabilitation hospitals (N = 5,428). Patients were separated into four groups based on BMI: non‐obese (BMI < 25 kg/m2), overweight (25–29.9 kg/m2), moderately obese (30–40 kg/m2), severely obese (BMI ≥ 40 kg/m2). All patients completed an interdisciplinary inpatient rehabilitation program post‐TKA. Total and individual functional independence measure (FIM) scores, length of stay (LOS), FIM efficiency scores, itemized hospital charges, and discharge disposition location, were collected.

Results: The percentage of total FIM change was 7.5% greater by the time of discharge in the non‐obese than in the very severely obese (P < 0.05). FIM efficiency was lowest in the severely obese as compared to the remaining groups (3.7 points (pts)/day vs. 4.0–4.3 pts/day; P = 0.044). The change in the motor FIM score from admission to discharge was 6.7–15.6% greater in the non‐obese than in the remaining groups (P < 0.05). The changes in cognition FIM, toilet transfer and walking without assistance scores were higher in the non‐obese as compared to the severely obese group (P < 0.05). The severely obese group had higher total, physical and occupational therapy and pharmacy charges than the remaining groups (P < 0.05).

Discussion: An excessive BMI does not prevent gains during inpatient rehabilitation; however, these gains are made less efficiently and at a higher cost than those made when the BMI is low.