bluuebunny/crossref_metadata_2025_split huggingface dataset:
ALMA Observations of Polarized 872 μm Dust Emission from the Protostellar Systems VLA 1623 and L1527
Authors: Harris Robert J. , Cox Erin G. , Looney Leslie W. , Li Zhi-Yun , Yang Haifeng , Fernández-López Manuel , Kwon Woojin , Sadavoy Sarah , Segura-Cox Dominique , Stephens Ian , Tobin John 
Published: July 2018

Abstract
We present high-sensitivity (σ

I
∼ 0.2–0.5 mJy, σ

QU
∼ 0.05 mJy), high-resolution (∼0.″12 −0.″2) observations of polarized 872 μm dust emission from the young multiple system VLA 1623 in ρ Ophiuchus and the protostar L1527 in Taurus. We detect the circumstellar material of VLA 1623A, the extended Keplerian disk surrounding VLA 1623A that we call VLA 1623CBdisk, VLA 1623B, VLA 1623W, and L1527 strongly in the polarized emission, at the ∼1%–3% level. We spatially resolve VLA 1623A into two sources, VLA 1623Aa and VLA 1623Ab, separated by ∼30 au and located within a cavity of radius ∼50 au within the circumbinary Keplerian disk, as well as the edge-on disk of VLA 1623W. The polarization angle of the emission is uniform across each protostellar source and nearly coincides with each disk’s minor axis. The offsets between the minor axis position angle and the polarization angle are not uniformly distributed at the P ≲ 2 × 10−4 level. The circumbinary disk surrounding VLA 1623Aab is azimuthally symmetrically polarized. Each compact source’s emission is partially optically thick (τ ≳ 1) at 872 μm, complicating interpretations of polarization involving aligned grains. We find evidence against alignment by radiative flux in each source, particularly in the edge-on VLA 1623W and L1527. We detect astrometric offsets between the polarized emission and the total intensity in VLA 1623Aa, VLA 1623Ab, and VLA 1623B, as predicted if self-scattering in the optically thick limit operates. We conclude that self-scattering is likely responsible for disk-scale polarization at 872 μm in these systems.
Stars Behind Bars. I. The Milky Way's Central Stellar Populations
Authors: Buck Tobias , Ness Melissa K. , Macciò Andrea V. , Obreja Aura , Dutton Aaron A. 
Published: July 2018

Abstract
We show for the first time that a fully cosmological hydrodynamical simulation can reproduce key properties of the innermost region of the Milky Way (MW). Our high-resolution simulation reproduces qualitatively the profile and kinematics of the MW’s boxy/peanut-shaped bulge, and hence we can use it to reconstruct and understand the bulge assembly. In particular, the age dependence of the X-shape morphology of the simulated bulge parallels the observed metallicity-dependent split in the red clump stars of the inner Galaxy. We use this feature to propose an observational metric that (after calibrated against a larger set of simulations) might allow us to quantify when the bulge formed from the disk. The metric we propose can be employed with upcoming survey data to constrain the age of the MW bar. From the split in stellar counts we estimate the formation of the 4 kpc scale bar in the simulation to have happened

Gyr ago, in good agreement with conventional methods to measure bar formation in simulations. We test the prospects for observationally differentiating the stars that belong to the bulge/bar compared to the surrounding disk, and we find that the inner disk and bulge are practically indistinguishable in both chemistry and ages.
A Powerful Radio-loud Quasar at the End of Cosmic Reionization
Authors: Bañados Eduardo , Carilli Chris , Walter Fabian , Momjian Emmanuel , Decarli Roberto , Farina Emanuele P. , Mazzucchelli Chiara , Venemans Bram P. 
Published: July 2018

Abstract
We present the discovery of the radio-loud quasar PSO J352.4034–15.3373 at z = 5.84 ± 0.02. This quasar is the radio brightest source known, by an order of magnitude, at z ∼ 6 with a flux density in the range of 8–100 mJy from 3 GHz to 230 MHz and a radio loudness parameter

. This source provides an unprecedented opportunity to study powerful jets and radio-mode feedback at the highest redshifts, and presents the first real chance to probe deep into the neutral intergalactic medium by detecting 21 cm absorption at the end of cosmic reionization.
HST Follow-up Observations of Two Bright z ∼ 8 Candidate Galaxies from the BoRG Pure-parallel Survey
Authors: Livermore R. C. , Trenti M. , Bradley L. D. , Bernard S. R. , Holwerda B. W. , Mason C. A. , Treu T. 
Published: July 2018

Abstract
We present follow-up imaging of two bright (L > L*) galaxy candidates at z ≳ 8 from the Brightest of Reionizing Galaxies (BoRG) survey with the F098M filter on the Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3). The F098M filter provides an additional constraint on the flux blueward of the spectral break, and the observations are designed to discriminate between low- and high-z photometric redshift solutions for these galaxies. Our results confirm one galaxy, BoRG_0116+1425_747, as a highly probable z ∼ 8 source, but reveal that BoRG_0116+1425_630—previously the brightest known z > 8 candidate (m
AB = 24.5)—is likely to be a z ∼ 2 interloper. As this source was substantially brighter than any other z > 8 candidate, removing it from the sample has a significant impact on the derived UV luminosity function in this epoch. We show that while previous BoRG results favored a shallow power-law decline in the bright end of the luminosity function prior to reionization, there is now no evidence for departure from a Schechter function form and therefore no evidence for a difference in galaxy formation processes before and after reionization.
They Might Be Giants: An Efficient Color-based Selection of Red Giant Stars
Authors: Conroy Charlie , Bonaca Ana , Naidu Rohan P. , Eisenstein Daniel J. , Johnson Benjamin D. , Dotter Aaron , Finkbeiner Douglas P. 
Published: July 2018

Abstract
We present a color-based method for identifying red giants based on the Pan-STARRS grz and WISE
W1 and W2 photometry. We utilize a subsample of bright stars with precise parallaxes from Gaia’s second data release (DR2) to verify that the color-based selection reliably separates dwarfs from giants. The selection is conservative in the sense that contamination is small (≈30%) but not all giants are included (the selection primarily identifies K giants). The color-based selection can be applied to stars brighter than W1 ≈ 16, more than two magnitudes fainter than techniques relying on shallower 2MASS photometry. Many streams and clouds are visible in the resulting sky maps, especially when binned by Gaia DR2 proper motions, including the Sagittarius stream, the Hercules–Aquila Cloud, the Eastern Banded Structure, Monoceros, and the Virgo Overdensity. In addition to the characterization of new and known stellar streams, we expect that this method for selecting red giants will enable detailed analysis of the diffuse stellar halo to distances exceeding 100 kpc.
In Situ Generation of Transverse Magnetohydrodynamic Waves from Colliding Flows in the Solar Corona
Authors: Antolin Patrick , Pagano Paolo , De Moortel Ineke , Nakariakov Valery M. 
Published: July 2018

Abstract
Transverse magnetohydrodynamic (MHD) waves permeate the solar atmosphere and are a candidate for coronal heating. However, the origin of these waves is still unclear. In this Letter, we analyze coordinated observations from Hinode/Solar Optical Telescope (SOT) and Interface Region Imaging Spectrograph
(
IRIS) of a prominence/coronal rain loop-like structure at the limb of the Sun. Cool and dense downflows and upflows are observed along the structure. A collision between a downward and an upward flow with an estimated energy flux of 107–108 erg cm−2 s−1 is observed to generate oscillatory transverse perturbations of the strands with an estimated ≈40 km s−1 total amplitude, and a short-lived brightening event with the plasma temperature increasing to at least 105 K. We interpret this response as sausage and kink transverse MHD waves based on 2D MHD simulations of plasma flow collision. The lengths, density, and velocity differences between the colliding clumps and the strength of the magnetic field are major parameters defining the response to the collision. The presence of asymmetry between the clumps (angle of impact surface and/or offset of flowing axis) is crucial for generating a kink mode. Using the observed values, we successfully reproduce the observed transverse perturbations and brightening, and show adiabatic heating to coronal temperatures. The numerical modeling indicates that the plasma β in this loop-like structure is confined between 0.09 and 0.36. These results suggest that such collisions from counter-streaming flows can be a source of in situ transverse MHD waves, and that for cool and dense prominence conditions such waves could have significant amplitudes.
Using technology acceptance model to measure the ese of social media for collaborative learning in Ghana
Authors: Amadu Latif , Syed Muhammad Sikandar , Mohammed Abubakari Sadiq , Owusu Grace , Lukman Sadia 
Published: July 2018

In this Digital era, thousands of teens in the universities use social network sites, it has become a way of life. Social Media Usage has recently received numerous debate in its impact on academics, with its advent, communities have become link to each other, but the lecture room still remains quite isolated, from other teachers, students, and a host of others who could potentially enhance learning. This study aimed at investigating the impact of social media usage on students’ academic performance through collaborative learning among university students in Ghana. (Based Davis et al,. 1989) Technology Acceptance Model (TAM), a conceptual framework was adopted for the study. To achieve the objectives, a quantitative data analysis method was employed. A total of 200 students were randomly surveyed for the study. Regression analysis revealed that, Interaction with peers, perceived ease of use and perceived usefulness had a significant positive relationship with collaborative learning. Furthermore, results suggested that there exist a significant mediation effects on the relationship between social media usage dimensions and academic performance. TAM does not take into account environment or economic factors that may influence a person’s intention to perform a behavior. The study recommends a clear mobile learning methodologies, rules and policies for integrating student activities on social media into their final grades.
A indústria no governo Lula: um enfoque sobre o possível processo de desindustrialização
Authors: Nunes Stephano Farias , Casonato Lucas , Da Costa Vinícius Borba 
Published: July 2018

O presente artigo tem por objetivo analisar os impactos das mudanças do PIB, da taxa Selic e do câmbio nas variações da proporção do emprego industrial sobre a População Economicamente Ativa da economia brasileirano período de 2004 a 2010. Para análise empírica este trabalho utilizou o modelo de painel com efeitos fixos. Oresultado do teste mostrou que o PIB apresenta relação direta com crescimento do emprego industrial, a Selic impactanegativamente sobre o crescimento do emprego industrial, assim como o câmbio que também apresentou coeficientenegativo, não corroborando a hipótese de que o câmbio depreciado favorece a geração de emprego no setor industrial.O crescimento constante da proporção do emprego industrial sobre o emprego total da economia mostra que o Brasilnão passou pelo processo de desindustrialização durante o período analisado.
INVESTIMENTO DIRETO EXTERNO NO BRASIL NO PERÍODO DE 2004 A 2012: EFEITOS NA ECONOMIA PARANAENSE
Authors: Devai Orlando Cesar 
Published: July 2018

Este artigo busca entender os fatores determinantes do aumento do fluxo internacional para o Brasil de US$ 18,14 bilhões em 2004, para US$ 65,27 em 2012, e seus efeitos na economia Paranaense. Para esta análise é utilizada a metodologia desenvolvida por Castro (1979) e Possas (1983) que considera o cenário econômico da origem e do destino dos recursos, e a fragmentação dos estudos em períodos com base em peculiaridades históricas e econômicas. O artigo inova em estudar o IDE em um estado separadamente. Conclui-se que no período de 2004 a 2007, o aumento do fluxo em direção ao Brasil se dá pela conjuntura internacional favorável, tendo como atrativo uma economia com mercado interno em crescimento. Após a crise internacional de 2008, os investimentos se dão como alternativa aos países ricos. Observa-se que o Paraná se beneficia do fluxo de IDE. Além do aumento do montante há um processo de diversificação e expansão para a região metropolitana de Curitiba e interior do estado, com diferenciação nos segmentos de investimento.
ANÁLISE DE SUSTENTABILIDADE DAS DÍVIDAS ESTADUAIS: IMPACTOS DO PLC 99/2013
Authors: Godoy Daniel Voigt 
Published: July 2018

O objetivo desse artigo é analisar os impactos do Projeto de Lei da Câmara dos Deputados 99/2013 sobre a sustentabilidade das dívidas estaduais. Propõe-se uma interpretação para o texto da lei, no que tange ao seu mecanismo de funcionamento e em seguida estima-se os impactos que as alterações propostas teriam sobre a trajetória de evolução das dívidas estaduais, utilizando uma abordagem estocástica. Encontram-se evidências de substancial redução dos desembolsos com serviço da dívida no período atual, bem como no período de refinanciamento do resíduo, além de um efeito indireto da substituição do índice de atualização monetária sobre a taxa média de crescimento real da RLR. Considera-se a hipótese de alteração do limite de comprometimento, definindo a condição de equilíbrio intertemporal entre os níveis de comprometimento atual e futuro e estimando parâmetros que satisfaçam essa condição.
CX3CR1+ Macrophages and CD8+ T Cells Control Intestinal IgA Production
Authors: Kim Young-In , Song Joo-Hye , Ko Hyun-Jeong , Kweon Mi-Na , Kang Chang-Yuil , Reinecker Hans-Christian , Chang Sun-Young 
Published: July 2018

Abstract
Secretory IgA is a key host defense mechanism that controls the intestinal microbiota. We investigated the role of CD11c+CX3CR1+CD64+ macrophages in IgA production in the intestine. Intestinal CX3CR1+ macrophages directly induced IgA secretion by B cells. Ag delivery to lamina propria (LP) CX3CR1+ macrophages specifically induced intestinal IgA production. The induction of IgA by CX3CR1+ macrophages required BAFF, a proliferation-inducing ligand, and TNF-α, but was surprisingly independent of TLR-mediated microbial recognition and retinoic acid signaling. IgA secretion by CX3CR1+ macrophages was enhanced by LP CD8+ T cells through the secretion of IL-9 and IL-13. CX3CR1+ macrophages and CD8+ T cells induced IgA production by B cells independently of mesenteric lymph nodes and Peyer patches. Our data reveal a previously unrecognized cellular circuitry in which LP CX3CR1+ macrophages, B cells, and CD8+ T cells coordinate the protective Ig secretion in the small intestine upon peripheral Ag delivery.
Immune Cells at the Fetomaternal Interface: How the Microenvironment Modulates Immune Cells To Foster Fetal Development
Authors: Schumacher Anne , Sharkey David J. , Robertson Sarah A. , Zenclussen Ana C. 
Published: July 2018

Abstract
Immune cells adapt their phenotypic and functional characteristics in response to the tissue microenvironment within which they traffic and reside. The fetomaternal interface, consisting of placental trophoblasts and the maternal decidua, is a highly specialized tissue with a unique and time-limited function: to nourish and support development of the semiallogeneic fetus and protect it from inflammatory or immune-mediated injury. It is therefore important to understand how immune cells within these tissues are educated and adapt to fulfill their biological functions. This review article focuses on the local regulatory mechanisms ensuring that both innate and adaptive immune cells appropriately support the early events of implantation and placental development through direct involvement in promoting immune tolerance of fetal alloantigens, suppressing inflammation, and remodeling of maternal uterine vessels to facilitate optimal placental function and fetal growth.
Impact of long-range transport over the Atlantic Ocean on Saharan dust optical and microphysical properties based on AERONET data
Authors: Velasco-Merino Cristian , Mateos David , Toledano Carlos , Prospero Joseph M. , Molinie Jack , Euphrasie-Clotilde Lovely , González Ramiro , Cachorro Victoria E. , Calle Abel , de Frutos Angel M. 
Published: July 2018

Abstract. Arid regions are a major source of mineral dust aerosol. Transport from these sources can have a great impact on aerosol climatology in distant regions. In order to assess the impact of dust on climate we must understand how dust properties change after long distance transport from sources. This study addresses the changes in columnar aerosol properties when mineral dust outbreaks from western Africa arrive over the eastern Caribbean after transport across the Atlantic Ocean, a transit of 5–7 days. We use data from the NASA Aerosol Robotic Network (AERONET) located at five Caribbean and two western Africa sites to characterize changes in columnar aerosol properties: aerosol optical depth (AOD), size distribution, single scattering albedo, and refractive indexes. We first characterized the local aerosol climatology at each site and then using air mass back trajectories we identified those days when trajectories over Caribbean sites back-tracked to western Africa. Over the period 1996–2014 we identify 3174 days, an average of 167 days per year, when the air mass over the Caribbean sites could be linked to at least one of the two western Africa sites. For 1162 of these days, AOD data are available for the Caribbean sites as well as for the corresponding western Africa sites about 5–7 days earlier, when the air mass passed over these sites. We identified dust outbreaks as those air masses yielding AOD  ≥  0.2 and an Ångström exponent below 0.6. On this basis of the total 1162 days, 484 meet the criteria for mineral dust outbreaks. We observe that the AOD at 440 nm decreases by about 0.16 or 30 % during transport. The volume particle size distribution shows a similar decrease in the volume concentration, mainly in the coarse mode. The single scattering albedo, refractive indexes, and asymmetry factor remain unchanged. The difference in the effective radius over western Africa sites with respect to Caribbean sites ranges between 0 and −0.3 µm. Finally we conclude that in about half of the cases only non-spherical dust particles are present in the atmosphere over the western Africa and Caribbean sites, while in the other cases dust particles were mixed with other types of aerosol particles.
The diurnal cycle of cloud profiles over land and ocean between 51° S and 51° N, seen by the CATS spaceborne lidar from the International Space Station
Authors: Noel Vincent , Chepfer Hélène , Chiriaco Marjolaine , Yorks John 
Published: July 2018

Abstract. We document, for the first time, how detailed vertical profiles of cloud
fraction (CF) change diurnally between 51∘ S and 51∘ N, by
taking advantage of 15 months of measurements from the Cloud-Aerosol
Transport System (CATS) lidar on the non-sun-synchronous International Space
Station (ISS). Over the tropical ocean in summer, we find few high clouds during daytime. At
night they become frequent over a large altitude range (11–16 km between
22:00 and 04:00 LT). Over the summer tropical continents,
but not over ocean, CATS observations reveal mid-level clouds (4–8 km above
sea level or a.s.l.) persisting all day long, with a weak diurnal cycle
(minimum at noon). Over the Southern Ocean, diurnal cycles appear for the
omnipresent low-level clouds (minimum between noon and 15:00) and
high-altitude clouds (minimum between 08:00 and 14:00). Both cycles are time
shifted, with high-altitude clouds following the changes in low-altitude
clouds by several hours. Over all continents at all latitudes during summer,
the low-level clouds develop upwards and reach a maximum occurrence at about
2.5 km a.s.l. in the early afternoon (around 14:00). Our work also shows that (1) the diurnal cycles of vertical profiles derived
from CATS are consistent with those from ground-based active sensors on a
local scale, (2) the cloud profiles derived from CATS measurements at local
times of 01:30 and 13:30 are consistent with those observed from CALIPSO at
similar times, and (3) the diurnal cycles of low and high cloud amounts (CAs)
derived from CATS are in general in phase with those derived from
geostationary imagery but less pronounced. Finally, the diurnal variability
of cloud profiles revealed by CATS strongly suggests that CALIPSO
measurements at 01:30 and 13:30 document the daily extremes of the cloud
fraction profiles over ocean and are more representative of daily averages
over land, except at altitudes above 10 km where they capture part of the
diurnal variability. These findings are applicable to other instruments with
local overpass times similar to CALIPSO's, such as all the other A-Train
instruments and the future EarthCARE mission.
Long-chain diols in rivers: distribution and potential biological sources
Authors: Lattaud Julie , Kirkels Frédérique , Peterse Francien , Freymond Chantal V. , Eglinton Timothy I. , Hefter Jens , Mollenhauer Gesine , Balzano Sergio , Villanueva Laura , van der Meer Marcel T. J. , Hopmans Ellen C. , Sinninghe Damsté Jaap S. , Schouten Stefan 
Published: July 2018

Abstract. Long-chain diols (LCDs) occur widespread in marine environments
and also in lakes and rivers. Transport of LCDs from rivers may impact the
distribution of LCDs in coastal environments, however relatively little is
known about the distribution and biological sources of LCDs in river systems.
In this study, we investigated the distribution of LCDs in suspended
particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine)
in relation with precipitation, temperature, and source catchments. The
dominant long-chain diol is the C32 1,15-diol followed by the
C30 1,15-diol in all studied river systems. In regions influenced
by marine waters, such as delta systems, the fractional abundance of the
C30 1,15-diol is substantially higher than in the river itself,
suggesting different LCD producers in marine and freshwater environments. A
change in the LCD distribution along the downstream transects of the rivers
studied was not observed. However, an effect of river flow is observed; i.e.,
the concentration of the C32 1,15-diol is higher in stagnant
waters such as reservoirs and during seasons with river low stands. A
seasonal change in the LCD distribution was observed in the Rhine, likely due
to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene
sequencing of SPM from the Rhine showed extremely low abundances of sequences
(i.e., < 0.32 % of total reads) related to known algal LCD
producers. Furthermore, incubation of the river water with
13C-labeled bicarbonate did not result in 13C
incorporation into LCDs. This indicates that the LCDs present are mainly of
fossil origin in the fast-flowing part of the Rhine. Overall, our results
suggest that the LCD producers in rivers predominantly reside in lakes or
side ponds that are part of the river system.