bluuebunny/crossref_metadata_2025 huggingface dataset:
InSAR Detection and Field Evidence for Thermokarst after a Tundra Wildfire, Using ALOS-PALSAR
Authors: Iwahana Go , Uchida Masao , Liu Lin , Gong Wenyu , Meyer Franz , Guritz Richard , Yamanokuchi Tsutomu , Hinzman Larry
Published: March 2016

Thermokarst is the process of ground subsidence caused by either the thawing of ice-rich permafrost or the melting of massive ground ice. The consequences of permafrost degradation associated with thermokarst for surface ecology, landscape evolution, and hydrological processes have been of great scientific interest and social concern. Part of a tundra patch affected by wildfire in northern Alaska (27.5 km2) was investigated here, using remote sensing and in situ surveys to quantify and understand permafrost thaw dynamics after surface disturbances. A two-pass differential InSAR technique using L-band ALOS-PALSAR has been shown capable of capturing thermokarst subsidence triggered by a tundra fire at a spatial resolution of tens of meters, with supporting evidence from field data and optical satellite images. We have introduced a calibration procedure, comparing burned and unburned areas for InSAR subsidence signals, to remove the noise due to seasonal surface movement. In the first year after the fire, an average subsidence rate of 6.2 cm/year (vertical) was measured. Subsidence in the burned area continued over the following two years, with decreased rates. The mean rate of subsidence observed in our interferograms (from 24 July 2008 to 14 September 2010) was 3.3 cm/year, a value comparable to that estimated from field surveys at two plots on average (2.2 cm/year) for the six years after the fire. These results suggest that this InSAR-measured ground subsidence is caused by the development of thermokarst, a thawing process supported by surface change observations from high-resolution optical images and in situ ground level surveys.
Protocol to Exploit Waiting Resources for UASNs
Authors: Hung Li-Ling , Luo Yung-Jeng
Published: March 2016

The transmission speed of acoustic waves in water is much slower than that of radio waves in terrestrial wireless sensor networks. Thus, the propagation delay in underwater acoustic sensor networks (UASN) is much greater. Longer propagation delay leads to complicated communication and collision problems. To solve collision problems, some studies have proposed waiting mechanisms; however, long waiting mechanisms result in low bandwidth utilization. To improve throughput, this study proposes a slotted medium access control protocol to enhance bandwidth utilization in UASNs. The proposed mechanism increases communication by exploiting temporal and spatial resources that are typically idle in order to protect communication against interference. By reducing wait time, network performance and energy consumption can be improved. A performance evaluation demonstrates that when the data packets are large or sensor deployment is dense, the energy consumption of proposed protocol is less than that of existing protocols as well as the throughput is higher than that of existing protocols.
A Novel Environmental Performance Evaluation of Thailand’s Food Industry Using Structural Equation Modeling and Fuzzy Analytic Hierarchy Techniques
Authors: Pipatprapa Anirut , Huang Hsiang-Hsi , Huang Ching-Hsu
Published: March 2016

Currently, the environment and sustainability are important topics for every industry. The food industry is particularly complicated in this regard because of the dynamic and complex character of food products and their production. This study uses structural equation modeling (SEM) and a fuzzy analytic hierarchy process (FAHP) to investigate which factors are suitable for evaluating the environmental performance of Thailand’s food industry. A first-stage questionnaire survey was conducted with 178 managers in the food industry that obtained a certificate from the Department of Industrial Work of Thailand to synthesize the performance measurement model and the significance of the relationship between the indicators. A second-stage questionnaire measured 18 experts’ priorities regarding the criteria and sub-factors involved in the different aspects and assessment items regarding environmental performance. SEM showed that quality management, market orientation, and innovation capability have a significantly positive effect on environmental performance. The FAHP showed that the experts were most concerned about quality management, followed by market orientation and innovation capability; the assessment items for quality policy, quality assurance, and customer orientation were of the most concern. The findings of this study can be referenced and support managerial decision making when monitoring environmental performance.
Life Cycle Analysis of Carbon Flow and Carbon Footprint of Harvested Wood Products of Larix principis-rupprechtii in China
Authors: Lun Fei , Liu Moucheng , Zhang Dan , Li Wenhua , Liu Junguo
Published: March 2016

Larix principis-rupprechtii is a native tree species in North China with a large distribution; and its harvested timbers can be used for producing wood products. This study focused on estimating and comparing carbon flows and carbon footprints of different harvested wood products (HWPs) from Larix principis-ruppechtii based on the life cycle analysis (from seedling cultivation to HWP final disposal). Based on our interviews and surveys, the system boundary in this study was divided into three processes: the forestry process, the manufacturing process, and the use and disposal process. By tracking carbon flows of HWPs along the entire life cycle, we found that, for one forest rotation period, a total of 26.81 tC/ha sequestered carbon was transferred into these HWPs, 66.2% of which were still stored in the HWP when the rotation period had ended; however, the HWP carbon storage decreased to 0.25 tC/ha (only 0.9% left) in the 100th year after forest plantation. The manufacturing process contributed more than 90% of the total HWP carbon footprint, but it was still smaller than the HWP carbon storage. In terms of the carbon storage and the carbon footprint, construction products had the largest net positive carbon balance compared to furniture and panel products. In addition, HWP are known to have a positive impact on global carbon mitigation because they can store parts of the sequestered carbon for a certain period of time and they have a substitution effect on carbon mitigation. Furthermore, there still exist great opportunities for carbon mitigation from HWPs through the use of cleaner energy and increasing the utilization efficiency of wood fuel.
Primers to amplify SNP markers in Epichloë canadensis (Clavicipitaceae)
Authors: Sullivan Terrence J. , Bultman Thomas L. , Schoolcraft Jennifer
Published: March 2016

Premise of the study:

Primers were designed to produce short amplicons containing single‐nucleotide polymorphisms (SNPs) in β‐tubulin (tubB) and translation elongation factor 1‐α (tefA) in Epichloë canadensis (Clavicipitaceae), an endophytic fungus of Elymus canadensis (Poaceae).

Methods and Results:

Primers to amplify regions of tubB and tefA containing suspected SNPs were designed and tested on individuals from six populations. Two tubB alleles were identified that differed by a single SNP, and three tefA alleles were identified that differed by a combination of two SNPs. All six populations tested were polymorphic for the tefA marker, and three of the populations were also polymorphic for the tubB marker. These primers are also predicted to amplify these regions in 11 additional epichloid species.

Conclusions:

Primers for short amplicons within tubB and tefA genes can be used to successfully genotype E. canadensis, making them useful markers for population genetic or landscape genomic studies.
SEEING THROUGH THE RING: NEAR-INFRARED PHOTOMETRY OF V582 MON (KH 15D)
Authors: Arulanantham Nicole A. , Herbst William , Cody Ann Marie , Stauffer John R. , Rebull Luisa M. , Agol Eric , Windemuth Diana , Marengo Massimo , Winn Joshua N. , Hamilton Catrina M. , Mundt Reinhard , Johns-Krull Christopher M. , Gutermuth Robert A.
Published: March 2016

We examine the light and color evolution of the T Tauri binary KH 15D through photometry obtained at wavelengths between 0.55 and 8.0 μm. The data were collected with A Novel Dual Imaging CAMera (ANDICAM) on the 1.3 m SMARTS telescope at Cerro-Tololo Inter-American Observatory and with InfraRed Array Camera on the Spitzer Space Telescope. We show that the system’s circumbinary ring, which acts as a screen that covers and uncovers different portions of the binary orbit as the ring precesses, has reached an orientation where the brighter component (star B) fully or nearly fully emerges during each orbital cycle. The fainter component (star A) remains fully occulted by the screen at all phases. The leading and trailing edges of the screen move across the sky at the same rate of ∼15 m s−1, consistent with expectation for a ring with a radius and width of ∼4 au and a precession period of ∼6500 years. Light and color variations continue to indicate that the screen is sharp edged and opaque at VRIJH wavelengths. However, we find an increasing transparency of the ring edge at 2.2, 3.6, and 4.5 μm. Reddening seen at the beginning of the eclipse that occurred during the CSI 2264 campaign particularly suggests selective extinction by a population of large dust grains. Meanwhile, the gradual bluing observed while star B is setting is indicative of forward scattering effects at the edge of the ring. The spectral energy distribution of the system at its bright phase shows no evidence of infrared excess emission that can be attributed to radiation from the ring or other dust component out to 8 μm.
NEW LUMINOUS ON SPECTRA FROM THE GALACTIC O-STAR SPECTROSCOPIC SURVEY
Authors: Walborn Nolan R. , Morrell Nidia I. , Barbá Rodolfo H. , Sota Alfredo
Published: March 2016

Two new ON supergiant spectra (bringing the total known to seven) and one new ONn giant (total of this class now eight) are presented; they have been discovered by the Galactic O-Star Spectroscopic Survey. These rare objects represent extremes in the mixing of CNO-cycled material to the surfaces of evolved, late-O stars, by uncertain mechanisms in the first category but likely by rotation in the second. The two supergiants are at the hot edge of the class, which is a selection effect from the behavior of defining N iii and C iii absorption blends, related to the tendency toward emission (Of effect) in the former. An additional N/C criterion first proposed by Bisiacchi et al. is discussed as a means to alleviate that effect, and it is relevant to the two new objects. The entire ON supergiant class is discussed; they display a fascinating diversity of detail undoubtedly related to the complexities of their extended atmospheres and winds that are sensitive to small differences in physical parameters, as well as to binary effects in some cases. Serendipitously, we have found significant variability in the spectrum of a little-known hypergiant with normal N, C spectra selected as a comparison for the anomalous objects. In contrast to the supergiants, the ONn spectra are virtual (nitrogen)-carbon copies of one another except for the degrees of line broadening, which emphasizes their probable unique origin and hence amenability to definitive astrophysical interpretation.
THE NEXT GENERATION VIRGO CLUSTER SURVEY. XIX. TOMOGRAPHY OF MILKY WAY SUBSTRUCTURES IN THE NGVS FOOTPRINT
Authors: Lokhorst Deborah , Starkenburg Else , McConnachie Alan W. , Navarro Julio F. , Ferrarese Laura , Côté Patrick , Liu Chengze , Peng Eric W. , Gwyn Stephen D. J. , Cuillandre Jean-Charles , Guhathakurta Puragra
Published: March 2016

The Next Generation Virgo Cluster Survey (NGVS) is a deep u*giz survey targeting the Virgo Cluster of galaxies at 16.5 Mpc. This survey provides high-quality photometry over an ∼100 deg2 region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo overdensity (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep u*gi imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) stars as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations (α ∼ 190°, δ ∼ −5°) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between ∼8 and 25 kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40 kpc, with a density maximum at ≃35 kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of ∼90 kpc—the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the ∼30° of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream with those predicted by leading stream models.
HIGH-TIME RESOLUTION IN SITU INVESTIGATION OF MAJOR COMETARY VOLATILES AROUND 67P/C–G AT 3.1–2.3 au MEASURED WITH ROSINA-RTOF
Authors: Mall U. , Altwegg K. , Balsiger H. , Bar-Nun A. , Berthelier J.-J. , Bieler A. , Bochsler P. , Briois C. , Calmonte U. , Combi M. R. , Dabrowski B. , Keyser J. De , Dhooghe F. , Fiethe B. , Fuselier S. A. , Galli A. , Garnier P. , Gasc S. , Gombosi T. I. , Hansen K. C. , Hässig M. , Hoang M. , Jäckel A. , Kopp E. , Korth A. , Roy L. Le , Magee B. , Marty B. , Mousis O. , Rème H. , Rubin M. , Sémon T. , Tzou C.-Y. , Waite J. H. , Wurz P.
Published: March 2016

Comets considered to be pristine objects contain key information about the early formation of the solar system. Their volatile components can provide clues about the origin and evolution of gases and ices in the comets. Measurements with ROSINA/RTOF at 67P/Churyumov–Gerasimenko have now allowed, for the first time, a direct in situ high-time resolution measurement of the most abundant cometary molecules originating directly from a comet’s nucleus over a long time-period, much longer than any previous measurements at a close distance to a comet between 3.1 and 2.3 au. We determine the local densities of H2O, CO2, and CO, and investigate their variabilities.
MASS–RADIUS RELATION FOR ROCKY PLANETS BASED ON PREM
Authors: Zeng Li , Sasselov Dimitar D. , Jacobsen Stein B.
Published: March 2016

Several small dense exoplanets are now known, inviting comparisons to Earth and Venus. Such comparisons require translating their masses and sizes to composition models of evolved multi-layer interior planets. Such theoretical models rely on our understanding of the Earth’s interior, as well as independently derived equations of state, but so far have not involved direct extrapolations from Earth’s seismic model: the Preliminary Reference Earth Model (PREM). To facilitate more detailed compositional comparisons between small exoplanets and the Earth, we derive here a semi-empirical mass–radius relation for two-layer rocky planets based on PREM,

, where CMF stands for core mass fraction. It is applicable to 1 ∼ 8 M
⊕ and a CMF of 0.0 ∼ 0.4. Applying this formula to Earth and Venus and several known small exoplanets with radii and masses measured to better than ∼30% precision gives a CMF fit of 0.26 ± 0.07.
CONSTRAINING AGN FEEDBACK IN MASSIVE ELLIPTICALS WITH SOUTH POLE TELESCOPE MEASUREMENTS OF THE THERMAL SUNYAEV–ZEL’DOVICH EFFECT
Authors: Spacek Alexander , Scannapieco Evan , Cohen Seth , Joshi Bhavin , Mauskopf Philip
Published: March 2016

Energetic feedback due to active galactic nuclei (AGNs) is likely to play an important role in the observed anti-hierarchical trend in the evolution of galaxies, and yet the energy injected into the circumgalactic medium by this process is largely unknown. One promising approach to constrain this feedback is through measurements of spectral distortions in the cosmic microwave background due to the thermal Sunyaev–Zeldovich (tSZ) effect, whose magnitude is directly proportional to the energy input by AGNs. With current instruments, making such measurements requires stacking large numbers of objects to increase signal-to-noise. While one possible target for such stacks is AGNs themselves, these are relatively scarce sources that contain contaminating emission that complicates tSZ measurements. Here we adopt an alternative approach and co-add South Pole Telescope SZ (SPT-SZ) survey data around a large set of massive quiescent elliptical galaxies at

, which are much more numerous and less contaminated than active AGNs, yet are subject to the same feedback processes from the AGNs they hosted in the past. We use data from the Blanco Cosmology Survey and VISTA Hemisphere Survey to create a large catalog of galaxies split up into two redshift bins: one with 3394 galaxies at

and one with 924 galaxies at

with typical stellar masses of

We then co-add the emission around these galaxies, resulting in a measured tSZ signal at

significance for the lower redshift bin and a contaminating signal at

for the higher redshift bin. To remove contamination due to dust emission, we use SPT-SZ source counts to model a contaminant source population in both the SPT-SZ bands and Planck high-frequency bands for a subset of 937 galaxies in the low-redshift bin and 240 galaxies in the high-redshift bin. This increases our detection to

for low redshifts and

for high redshifts. We find the mean angularly integrated Compton-y values to be

Mpc2 for low redshifts and

Mpc2 for high redshifts, corresponding to total thermal energies of

erg and

erg, respectively. These numbers are higher than expected from simple theoretical models that do not include AGN feedback, and serve as constraints that can be applied to current simulations of massive galaxy formation.
A REMARKABLY LUMINOUS GALAXY AT Z = 11.1 MEASURED WITH HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY
Authors: Oesch P. A. , Brammer G. , Dokkum P. G. van , Illingworth G. D. , Bouwens R. J. , Labbé I. , Franx M. , Momcheva I. , Ashby M. L. N. , Fazio G. G. , Gonzalez V. , Holden B. , Magee D. , Skelton R. E. , Smit R. , Spitler L. R. , Trenti M. , Willner S. P.
Published: March 2016

We present Hubble WFC3/IR slitless grism spectra of a remarkably bright z ≳ 10 galaxy candidate, GN-z11, identified initially from CANDELS/GOODS-N imaging data. A significant spectroscopic continuum break is detected at

. The new grism data, combined with the photometric data, rule out all plausible lower redshift solutions for this source. The only viable solution is that this continuum break is the Lyα break redshifted to

, just ∼400 Myr after the Big Bang. This observation extends the current spectroscopic frontier by 150 Myr to well before the Planck (instantaneous) cosmic reionization peak at z ∼ 8.8, demonstrating that galaxy build-up was well underway early in the reionization epoch at z > 10. GN-z11 is remarkably, and unexpectedly, luminous for a galaxy at such an early time: its UV luminosity is 3×  larger than

measured at z ∼ 6−8. The Spitzer IRAC detections up to 4.5 μm of this galaxy are consistent with a stellar mass of  ∼109 M
⊙. This spectroscopic redshift measurement suggests that James Webb Space Telescope (JWST) will be able to similarly and easily confirm such sources at z > 10 and characterize their physical properties through detailed spectroscopy. Furthermore, WFIRST, with its wide-field near-IR imaging, would find large numbers of similar galaxies and contribute greatly to JWST's spectroscopy, if it is launched early enough to overlap with JWST.
CONSTRAINING THE DYNAMICAL IMPORTANCE OF HOT GAS AND RADIATION PRESSURE IN QUASAR OUTFLOWS USING EMISSION LINE RATIOS
Authors: Stern Jonathan , Faucher-Giguère Claude-André , Zakamska Nadia L. , Hennawi Joseph F.
Published: March 2016

Quasar feedback models often predict an expanding hot gas bubble that drives a galaxy-scale outflow. In many circumstances this hot gas radiates inefficiently and is therefore difficult to observe directly. We present an indirect method to detect the presence of a hot bubble using hydrostatic photoionization calculations of the cold (

) line-emitting gas. We compare our calculations with observations of the broad line region, the inner face of the torus, the narrow line region (NLR), and the extended NLR, and thus constrain the hot gas pressure at distances

from the center. We find that emission line ratios observed in the average quasar spectrum are consistent with radiation-pressure-dominated models on all scales. On scales

a dynamically significant hot gas pressure is ruled out, while on larger scales the hot gas pressure cannot exceed six times the local radiation pressure. In individual quasars, ≈25% of quasars exhibit NLR ratios that are inconsistent with radiation-pressure-dominated models, although in these objects the hot gas pressure is also unlikely to exceed the radiation pressure by an order of magnitude or more. The derived upper limits on the hot gas pressure imply that the instantaneous gas pressure force acting on galaxy-scale outflows falls short of the time-averaged force needed to explain the large momentum fluxes

inferred for galaxy-scale outflows. This apparent discrepancy can be reconciled if optical quasars previously experienced a buried, fully obscured phase during which the hot gas bubble was more effectively confined and during which galactic wind acceleration occurred.
THE RADIAL AND ROTATIONAL VELOCITIES OF PSO J318.5338-22.8603, A NEWLY CONFIRMED PLANETARY-MASS MEMBER OF THE β PICTORIS MOVING GROUP
Authors: Allers K. N. , Gallimore J. F. , Liu Michael C. , Dupuy Trent J.
Published: March 2016

PSO J318.5338−22.8603 is an extremely red planetary-mass object that has been identified as a candidate member of the β Pictoris moving group based on its spatial position and tangential velocity. We present a high-resolution K-band spectrum of PSO J318.5338−22.8603. Using a forward modeling Markov Chain Monte Carlo approach, we report the first measurement of the radial velocity and v sin(i) of PSO J318.5−22,

km s−1, and

km s−1, respectively. We calculate the space velocity and position of PSO J318.5−22 and confirm that it is a member of the β Pictoris moving group. Adopting an age of 23 ± 3 Myr for PSO J318.5−22, we determine a mass of 8.3 ± 0.5 M
Jup and an effective temperature of

K using evolutionary models. PSO J318.5338−22.8603 is intermediate in mass and temperature to the directly imaged planets β Pictoris b and 51 Eridani b, making it an important benchmark object in the sequence of the planetary-mass members of the β Pictoris moving group. Combining our v sin(i) measurement with recent photometric variability data, we constrain the inclination of PSO J318.5−22 to >29° and its rotational period to 5–10.2 hr. The equatorial velocity of PSO J318.5−22 indicates that its rotation is consistent with an extrapolation of the velocity–mass relationship for solar system planets.
ORION’S VEIL. IV. H2 EXCITATION AND GEOMETRY
Authors: Abel N. P. , Ferland G. J. , O’Dell C. R. , Troland T. H.
Published: March 2016

The foreground Veil of material that lies in front of the Orion Nebula is the best studied sample of the interstellar medium because we know where it is located, how it is illuminated, and the balance of thermal and magnetic energy. In this work, we present high-resolution STIS observations toward the Trapezium, with the goal of better understanding the chemistry and geometry of the two primary Veil layers, along with ionized gas along the line of sight. The most complete characterization of the rotational/vibrational column densities of H2 in the almost purely atomic components of the Veil are presented, including updates to the Cloudy model for H2 formation on grain surfaces. The observed H2 is found to correlate almost exclusively with Component B. The observed H2, observations of CI, CI*, and CI**, and theoretical calculations using Cloudy allow us to place the tightest constraints yet on the distance, density, temperature, and other physical characteristics for each cloud component. We find the H2 excitation spectrum observed in the Veil is incompatible with a recent study that argued that the Veil was quite close to the Trapezium. The nature of a layer of ionized gas lying between the Veil and the Trapezium is characterized through the emission and absorption lines it produces, which we find to be the blueshifted component observed in S iii and P iii absorption. We deduce that, within the next 30–60 thousand years, the blueshifted ionized layer and Component B will merge, which will subsequently merge with Component A in the next one million years.
WHAT IS CONTROLLING THE FRAGMENTATION IN THE INFRARED DARK CLOUD G14.225–0.506?: DIFFERENT LEVELS OF FRAGMENTATION IN TWIN HUBS
Authors: Busquet Gemma , Estalella Robert , Palau Aina , Liu Hauyu Baobab , Zhang Qizhou , Girart Josep Miquel , de Gregorio-Monsalvo Itziar , Pillai Thushara , Anglada Guillem , Ho Paul T. P.
Published: March 2016

We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225–0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 μm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clump elongated in the direction of the associated filament. At small scales, the SMA images reveal that both hubs fragment into several dust condensations. The fragmentation level was assessed under the same conditions and we found that hub-N presents 4 fragments while hub-S is more fragmented, with 13 fragments identified. We studied the density structure by means of a simultaneous fit of the radial intensity profile at 870 and 350 μm and the spectral energy distribution adopting a Plummer-like function to describe the density structure. The parameters inferred from the model are remarkably similar in both hubs, suggesting that density structure could not be responsible for determining the fragmentation level. We estimated several physical parameters, such as the level of turbulence and the magnetic field strength, and we found no significant differences between these hubs. The Jeans analysis indicates that the observed fragmentation is more consistent with thermal Jeans fragmentation compared with a scenario in which turbulent support is included. The lower fragmentation level observed in hub-N could be explained in terms of stronger UV radiation effects from a nearby H ii region, evolutionary effects, and/or stronger magnetic fields at small scales, a scenario that should be further investigated.
CARBON CHAINS AND METHANOL TOWARD EMBEDDED PROTOSTARS*
Authors: Graninger Dawn M. , Wilkins Olivia H. , Öberg Karin I.
Published: March 2016

Large interstellar organic molecules are potential precursors of prebiotic molecules. Their formation pathways and chemical relationships with one another and simpler molecules are therefore of great interest. In this paper we address the relationships between two classes of large organic molecules, carbon chains and saturated complex organic molecules at the early stages of star formation through observations of C4H and CH3OH. We surveyed these molecules with the IRAM 30 m telescope toward 16 deeply embedded low-mass protostars selected from the Spitzer c2d ice survey. We find that CH3OH and C4H are positively correlated, indicating that these two classes of molecules can coexist during the embedded protostellar stage. The C4H/CH3OH gas abundance ratio tentatively correlates with the CH4/CH3OH ice abundance ratio in the same lines of sight. This relationship supports a scenario where carbon chain formation in protostellar envelopes begins with CH4 ice desorption.
TOWARD THE ASTRONOMICAL DETECTION OF THE PROTON-BOUND COMPLEX NN–HCO+: IMPLICATIONS FOR THE SPECTRA OF PROTOPLANETARY DISKS
Authors: Fortenberry Ryan C. , Francisco Joseph S. , Lee Timothy J.
Published: March 2016

Proton-bound complexes have been hypothesized as further means of detecting the nitrogen molecule in the interstellar medium. The study of such complexes has largely been hindered by the necessary experimental setups utilized or by their difficulty in producing and/or analyzing computed potential energy surfaces. Here the NN–HCO+ proton-bound complex is analyzed via quartic force fields (QFFs). While QFFs have produced meaningful results for other proton-bound complexes, they have been hindered by double-well potentials or flat potential surfaces. NN–HCO+ is not affected by these constraints. This strongly dipolar (3.63 D) molecule can be observed rotationally unlike the more heavily analyzed OCHCO+ and NNHNN+ proton-bound complexes. Additionally, the large absorption feature corresponding to the proton motion, a hallmark of proton-bound complexes, is much higher in frequency at 2547.1 cm−1, changing the range of experimental observation for the bright frequency. NN–HCO+ is hypothesized to be present in protoplanetary disks where N2H+ and CO are known. As such, it may help to influence the nitrogen budget of planet-forming astronomical regions.
CONTRACTION SIGNATURES TOWARD DENSE CORES IN THE PERSEUS MOLECULAR CLOUD
Authors: Campbell J. L. , Friesen R. K. , Martin P. G. , Caselli P. , Kauffmann J. , Pineda J. E.
Published: March 2016

We report the results of an HCO+ (3–2) and N2D+ (3–2) molecular line survey performed toward 91 dense cores in the Perseus molecular cloud using the James Clerk Maxwell Telescope, to identify the fraction of starless and protostellar cores with systematic radial motions. We quantify the HCO+ asymmetry using a dimensionless asymmetry parameter δ

v
, and identify 20 cores with significant blue or red line asymmetries in optically thick emission indicative of collapsing or expanding motions, respectively. We separately fit the HCO+ profiles with an analytic collapse model and determine contraction (expansion) speeds toward 22 cores. Comparing the δ

v
and collapse model results, we find that δ

v
is a good tracer of core contraction if the optically thin emission is aligned with the model-derived systemic velocity. The contraction speeds range from subsonic (0.03 km s−1) to supersonic (0.4 km s−1), where the supersonic contraction speeds may trace global rather than local core contraction. Most cores have contraction speeds significantly less than their free-fall speeds. Only 7 of 28 starless cores have spectra well-fit by the collapse model, which more than doubles (15 of 28) for protostellar cores. Starless cores with masses greater than the Jeans mass (M/M
J > 1) are somewhat more likely to show contraction motions. We find no trend of optically thin non-thermal line width with M/M
J, suggesting that any undetected contraction motions are small and subsonic. Most starless cores in Perseus are either not in a state of collapse or expansion, or are in a very early stage of collapse.
MOLECULAR DISTRIBUTION IN THE SPIRAL ARM OF M51
Authors: Watanabe Yoshimasa , Sakai Nami , Sorai Kazuo , Ueda Junko , Yamamoto Satoshi
Published: March 2016

Molecular line images of 13CO, C18O, CN, CS, CH3OH, and HNCO are obtained toward the spiral arm of M51 at a

resolution with the Combined Array for Research in Millimeter-wave Astronomy. Distributions of the molecules averaged over a 300 pc scale are found to be almost similar to one another and to essentially trace the spiral arm. However, the principal component analysis shows a slight difference of distributions among molecular species, particularly for CH3OH and HNCO. These two species do not correlate well with the star formation rate, implying that they are not enhanced by local star formation activities but by galactic-scale phenomena such as spiral shocks. Furthermore, the distributions of HNCO and CH3OH are found to be slightly different, and their origins deserve further investigation. The present results provide us with an important clue for understanding the 300 pc scale chemical composition in the spiral arm and its relation to galactic-scale dynamics.
UNIFIED MICROSCOPIC–MACROSCOPIC MONTE CARLO SIMULATIONS OF COMPLEX ORGANIC MOLECULE CHEMISTRY IN COLD CORES
Authors: Chang Qiang , Herbst Eric
Published: March 2016

The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules (COMs). The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which COMs and the methoxy radical can be formed on dust grains via a so-called chain reaction mechanism, in a similar manner to CO2. A unified gas-grain microscopic–macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the nonthermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of methoxy are also included. The observed abundances of a variety of organic molecules in cold cores can be reproduced in our models. The strong correlation between the abundances of methyl formate and dimethyl ether in cold cores can also be explained. Nondiffusive chemical reactions on dust grain surfaces may play a key role in the formation of some COMs.
EVOLUTION OF MAGNETIC HELICITY AND ENERGY SPECTRA OF SOLAR ACTIVE REGIONS
Authors: Zhang Hongqi , Brandenburg Axel , Sokoloff D. D.
Published: March 2016

We adopt an isotropic representation of the Fourier-transformed two-point correlation tensor of the magnetic field to estimate the magnetic energy and helicity spectra as well as current helicity spectra of two individual active regions (NOAA 11158 and NOAA 11515) and the change of the spectral indices during their development as well as during the solar cycle. The departure of the spectral indices of magnetic energy and current helicity from 5/3 are analyzed, and it is found that it is lower than the spectral index of the magnetic energy spectrum. Furthermore, the fractional magnetic helicity tends to increase when the scale of the energy-carrying magnetic structures increases. The magnetic helicity of NOAA 11515 violates the expected hemispheric sign rule, which is interpreted as an effect of enhanced field strengths at scales larger than 30–60 Mm with opposite signs of helicity. This is consistent with the general cycle dependence, which shows that around the solar maximum the magnetic energy and helicity spectra are steeper, emphasizing the large-scale field.
UNRAVELING THE COMPLEX STRUCTURE OF AGN-DRIVEN OUTFLOWS. I. KINEMATICS AND SIZES
Authors: Karouzos Marios , Woo Jong-Hak , Bae Hyun-Jin
Published: March 2016

Outflows driven by active galactic nuclei (AGNs) are often invoked as agents of the long-sought AGN feedback. Yet, characterizing and quantifying the impact on their host galaxies has been challenging. We present Gemini Multi-Object Spectrograph integral field unit data of six local (z 

) and luminous (L

erg s−1) type 2 AGNs. In the first of a series of papers, we investigate the kinematics and constrain the size of the outflows. The ionized gas kinematics can be described as a superposition of a gravitational component that follows the stellar motion and an outflow-driven component that shows large velocity (up to 600 km s−1) and large velocity dispersion (up to 800 km s−1). Using the spatially resolved measurements of the gas, we kinematically measure the size of the outflow, which is found to be between 1.3 and 2.1 kpc. Owing to the lack of a detailed kinematic analysis, previous outflow studies likely overestimate their size by up to more than a factor of two, depending on how the size is estimated and whether the [O iii] or Hα emission line is used. The relatively small size of the outflows for all six of our objects casts doubts on their potency as a mechanism for negative AGN feedback.
NuSTAR AND XMM-NEWTON OBSERVATIONS OF THE HARD X-RAY SPECTRUM OF CENTAURUS A
Authors: Fürst F. , Müller C. , Madsen K. K. , Lanz L. , Rivers E. , Brightman M. , Arevalo P. , Baloković M. , Beuchert T. , Boggs S. E. , Christensen F. E. , Craig W. W. , Dauser T. , Farrah D. , Graefe C. , Hailey C. J. , Harrison F. A. , Kadler M. , King A. , Krauß F. , Madejski G. , Matt G. , Marinucci A. , Markowitz A. , Ogle P. , Ojha R. , Rothschild R. , Stern D. , Walton D. J. , Wilms J. , Zhang W.
Published: March 2016

We present simultaneous XMM-Newton and Nuclear Spectroscopic Telescope Array (NuSTAR) observations spanning 3–78 keV of the nearest radio galaxy, Centaurus A (Cen A). The accretion geometry around the central engine in Cen A is still debated, and we investigate possible configurations using detailed X-ray spectral modeling. NuSTAR imaged the central region of Cen A with subarcminute resolution at X-ray energies above 10 keV for the first time, but found no evidence for an extended source or other off-nuclear point sources. The XMM-Newton and NuSTAR spectra agree well and can be described with an absorbed power law with a photon index Γ = 1.815 ± 0.005 and a fluorescent

line in good agreement with literature values. The spectrum does not require a high-energy exponential rollover, with a constraint of E
fold > 1 MeV. A thermal Comptonization continuum describes the data well, with parameters that agree with values measured by INTEGRAL, in particular an electron temperature kT

e
between ≈100–300 keV and seed photon input temperatures between 5 and 50 eV. We do not find evidence for reflection or a broad iron line and put stringent upper limits of R < 0.01 on the reflection fraction and accretion disk illumination. We use archival Chandra data to estimate the contribution from diffuse emission, extra-nuclear point sources, and the outer X-ray jet to the observed NuSTAR and XMM-Newton X-ray spectra and find the contribution to be negligible. We discuss different scenarios for the physical origin of the observed hard X-ray spectrum and conclude that the inner disk is replaced by an advection-dominated accretion flow or that the X-rays are dominated by synchrotron self-Compton emission from the inner regions of the radio jet or a combination thereof.
DETERMINING TYPE Ia SUPERNOVA HOST GALAXY EXTINCTION PROBABILITIES AND A STATISTICAL APPROACH TO ESTIMATING THE ABSORPTION-TO-REDDENING RATIO RV
Authors: Cikota Aleksandar , Deustua Susana , Marleau Francine
Published: March 2016

We investigate limits on the extinction values of Type Ia supernovae (SNe Ia) to statistically determine the most probable color excess, E(B – V), with galactocentric distance, and use these statistics to determine the absorption-to-reddening ratio, R

V
, for dust in the host galaxies. We determined pixel-based dust mass surface density maps for 59 galaxies from the Key Insight on Nearby Galaxies: a Far-infrared Survey with Herschel (KINGFISH). We use SN Ia spectral templates to develop a Monte Carlo simulation of color excess E(B – V) with R

V
 = 3.1 and investigate the color excess probabilities E(B – V) with projected radial galaxy center distance. Additionally, we tested our model using observed spectra of SN 1989B, SN 2002bo, and SN 2006X, which occurred in three KINGFISH galaxies. Finally, we determined the most probable reddening for Sa–Sap, Sab–Sbp, Sbc–Scp, Scd–Sdm, S0, and irregular galaxy classes as a function of R/R
25. We find that the largest expected reddening probabilities are in Sab–Sb and Sbc–Sc galaxies, while S0 and irregular galaxies are very dust poor. We present a new approach for determining the absorption-to-reddening ratio R

V
using color excess probability functions and find values of R

V
= 2.71 ± 1.58 for 21 SNe Ia observed in Sab–Sbp galaxies, and R

V
= 1.70 ± 0.38, for 34 SNe Ia observed in Sbc–Scp galaxies.
A PROTOSOLAR NEBULA ORIGIN FOR THE ICES AGGLOMERATED BY COMET 67P/CHURYUMOV–GERASIMENKO
Authors: Mousis O. , Lunine J. I. , Luspay-Kuti A. , Guillot T. , Marty B. , Ali-Dib M. , Wurz P. , Altwegg K. , Bieler A. , Hässig M. , Rubin M. , Vernazza P. , Waite J. H.
Published: March 2016

The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula (PSN) is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the PSN. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the PSN. On the basis of existing laboratory and modeling data, we find that the N2/CO and Ar/CO ratios measured in the coma of the Jupiter-family comet 67P/Churyumov–Gerasimenko by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument on board the European Space Agency’s Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N2/CO and Ar/CO ratios in 67P/Churyumov–Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov–Gerasimenko is impoverished in Ar and N2, the volatile enrichments observed in Jupiter’s atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.
Tenofovir Alafenamide as Part of a Salvage Regimen in a Patient with Multi-Drug Resistant HIV and Tenofovir-DF-Associated Renal Tubulopathy
Authors: Mikula James M , Manion Maura M , Maldarelli Frank , Suarez Lucila M , Norman-Wheeler Jaha F , Ober Alex G , Dewar Robin L , Kopp Jeffrey B , Lane H Clifford , Pau Alice K
Published: March 2016

We describe a patient with two recent episodes of tenofovir disoproxil fumarate (TDF)-associated acute kidney injury and six-class drug-resistant HIV infection who achieved and maintained viral suppression without worsening kidney function on a regimen including tenofovir alafenamide (TAF) through 48 weeks of therapy. The safety and efficacy of TAF in patients with TDF-associated renal tubulopathy and multiple drug resistant HIV has not yet been described. TAF may represent a useful option to maximally suppress HIV in patients with these complications.
Community Drug Abuse Prevention in a Hmong Village in Thailand
Authors: Keawkingkeo Suwanee
Published: March 2016

The goal of this project was to implement a model of drug abuse prevention, drawing on health care, psychosocial and legal principles, in a selected village community in Thailand. Primary, secondary, and tertiary prevention strategies were used within a nursing conceptual framework that included the interactions among the person, drugs, and environment. An initial community survey revealed 112 addicted individuals and identified many at-risk groups, such as children of addicted parents, adolescents, and women.

Primary health care and dental health services were provided in the community, as well as drug abuse education and activities for school children and at-risk groups. Treatment camps were also established in the community on two occasions to provide detoxification and rehabilitation services for addicted individuals. At the end of the 3-year program, there were no new addicted individuals, and the number of addicted individuals decreased from 112 to 50 (after first treatment) and 26 (after second treatment). In addition, the villagers were more aware of problems related to using opium and heroin and of modern, approved drugs to treat illnesses. The prevention strategies were beneficial for the community members, as well as the addicted individuals and their families.
Social Support Among Homeless and Housed Mothers: An Integrative Review
Authors: Meadows-Oliver Mikki
Published: March 2016

Homelessness has been associated with levels of stress beyond the normal strain of living in poverty. For mothers who are homeless, support from their social networks may provide a buffer from some of the stresses associated with being homeless. To better understand the relationship between social support and female-headed homeless families, an integrative review was conducted of 12 research articles that compare social support among low-income housed mothers and homeless mothers, using guidelines set forth by Ganong.

The included studies revealed four significant attributes of social support among housed and homeless mothers: size of the social support network; composition of the social support network; contacts with members of the social support network; and perceived support from members of the social support network. Nurses who work with homeless families are in a position to help develop ways for these families to cultivate and maintain their social support networks while homeless. Nurses can be available to offer support, including the necessary mental health services or referrals.

Ms. Meadows-Oliver is Lecturer, Yale University School of Nursing, New Haven, Connecticut.

Address correspondence to Mikki Meadows-Oliver, MSN, MPH, Lecturer, Yale University School of Nursing, 100 Church Street South, Suite 200, PO Box 9740, New Haven, CT 06536-0740; e-mail:
mikki.meadows@yale.edu.
The Needs of Adolescent Girls who Self-Harm
Authors: Cerdorian Kimberly
Published: March 2016

The incidence of self-harm by adolescent girls without intent of suicide is dramatically increasing in the United States. This article explores contributing factors, including internal and external stressors that are reaching epidemic proportions within society, and examines events that appear to contribute to self-harm (e.g., physical, sexual, and emotional abuse; personal lack of control), and the professional theories of self-harm behind these behaviors. Understanding the physical and emotional effects of self-harm helps clarify the behavior as both adaptive and self-destructive. Ultimately, this article aims to differentiate self-harm from suicide attempts and comorbidity, and move toward meaningful, effective, long-lasting assessment and treatment strategies.
Telomeres, species differences, and unusual telomeres in vertebrates: presenting challenges and opportunities to understanding telomere dynamics
Authors: Ingles Emory D. , Deakin Janine E.
Published: March 2016

There has been increasing interest in the use of telomeres as biomarkers of stress, cellular ageing and life-histories. However, the telomere landscape is a diverse feature, with noticeable differences between species, a fact which is highlighted by the unusual telomeres of various vertebrate organisms. We broadly review differences in telomere dynamics among vertebrates, and emphasize the need to understand more about telomere processes and trends across species. As part of these species differences, we review unusual telomeres in vertebrates. This includes mega-telomeres, which are present across a diverse set of organisms, but also focusing on the unusual telomeres traits of marsupials and monotremes, which have seen little to no prior discussion, yet uniquely stand out from other unusual telomere features discovered thus far. Due to the presence of at least two unique telomere features in the marsupial family Dasyuridae, as well as to the presence of physiological strategies semelparity and torpor, which have implications for telomere life-histories in these species, we suggest that this family has a very large potential to uncover novel information on telomere evolution and dynamics.