bluuebunny/crossref_metadata_2025_split huggingface dataset:
Millennial scale climate-fire-vegetation interactions in a mid-elevation mixed coniferous forest, Mission Range, northwestern Montana, USA
Authors: Alt Mio , McWethy David B. , Everett Rick , Whitlock Cathy 
Published: May 2018

AbstractMixed coniferous forests are widespread at middle elevations in the Northern Rocky Mountains, yet relatively little is known about their long-term vegetation and fire history. Pollen and charcoal records from Twin Lakes, in the Mission Range of northwestern Montana provide information on mixed-coniferous forest development and fire activity over the last 15,000 years. These data suggest an open parkland and minimal fire activity before 13,500 cal yr BP, consistent with cold, dry conditions. Increases inPinuspollen after 13,500 cal yr BP indicate a transition to closed forests, and a slight rise in fire activity as conditions warmed and fuel biomass increased. High levels ofArtemisiapollen between 10,000 and 6000 cal yr BP suggest an open forest during the early Holocene when conditions were warmer and drier than present. Low-severity fires likely maintained open forest/shrublands but produced little charcoal during this interval. Present-day mixed-coniferous forests were established in the last 6 ka and included forest taxa characteristic of low- (Pseudotsuga-Larix/Pinus ponderosa)and high-severity fire regimes (Picea/Abies). Increased climate variability and anthropogenic burning may have helped maintain heterogeneous, mixed-coniferous forests during the last several millennia when climate conditions became cooler and wetter.
A Few Remarks on the Tube Algebra of a Monoidal Category
Authors: Neshveyev Sergey , Yamashita Makoto 
Published: May 2018

AbstractWe prove two results on the tube algebras of rigid C*-tensor categories. The first is that the tube algebra of the representation category of a compact quantum groupGis a full corner of the Drinfeld double ofG. As an application, we obtain some information on the structure of the tube algebras of the Temperley–Lieb categories 𝒯ℒ(d) ford> 2. The second result is that the tube algebras of weakly Morita equivalent C*-tensor categories are strongly Morita equivalent. The corresponding linking algebra is described as the tube algebra of the 2-category defining the Morita context.
Untangling the hidden intrathalline microalgal diversity inParmotrema pseudotinctorum:Trebouxia crespoanasp. nov.
Authors: ŠKALOUD Pavel , MOYA Patricia , MOLINS Arántzazu , PEKSA Ondřej , SANTOS-GUERRA Arnoldo , BARRENO Eva 
Published: May 2018

AbstractIntrathalline phycobiont diversity was investigated in a rosette-forming lichen,Parmotrema pseudotinctorum, using a combination of Sanger sequencing, 454-pyrosequencing, conventional light and confocal microscopy, and transmission electron microscopy. A total of 39 thalli sampled in five Canary Island populations were investigated. Three novel lineages of lichen phycobionts were detected, all being inferred within theTrebouxiaclade G. The most abundant phycobiont lineage, occurring in all lichen populations investigated, is described here asTrebouxia crespoanasp. nov. This species produces spherical to pyriform cells possessing a crenulate chloroplast with lobes elongated at their ends, and onecorticola-type pyrenoid with very thin, unbranched tubules of curved profile.Trebouxia crespoanais clearly distinguished from all otherTrebouxiaspecies by a characteristic cap-like cell wall thickening produced on one side of vegetative cells, and the larger size of vegetative cells that reach 21(–26) µm in diameter.
Beta diversity and similarity of lichen communities as a sign of the times
Authors: GIORDANI Paolo , BRUNIALTI Giorgio , CALDERISI Marco , MALASPINA Paola , FRATI Luisa 
Published: May 2018

AbstractCurrently, change in lichen community structure depends on a combination of several pollutants instead of just one. Consequently, alpha lichen diversity no longer represents an effective response variable for assessing trends in atmospheric pollutants over time. Here we investigated the value of the relationship between alpha diversity and different aspects of gamma diversity (similarity, replacement and differences in richness of species) together with that of beta diversity (calculated as the sum of replacement and difference in richness of species), for assessing complex variations in epiphytic lichen communities in response to a changing pollution scenario. We considered an area subjected to extreme variation in atmospheric pollution in recent decades and explored temporal and spatial aspects of lichen community succession over short-, intermediate- and long-term reference periods. We found that variation in lichen communities for long- and intermediate-term reference periods was strongly dependent on the alpha diversity of single trees at the beginning of the observation period. The occurrence of nitrophytic species, which responded to the decrease in SO2 concentrations, contribute to this trend. The effect of land use was observed only over long observation periods, with trees in urban areas showing less variation than those located in rural areas. In particular, the analysis of similarity, species replacement and differences in richness of tree pairs demonstrated that trends and patterns within lichen communities are neither always nor to the same extent associated with alpha diversity. Our results show that a thorough study of gamma diversity, including beta diversity and similarity, is required to detect changes in air quality in long-term biomonitoring surveys.
The role of neonatal pulmonary morbidity in the longitudinal patterns of hospitalisation for respiratory infection during the first year of life
Authors: Betts Kim S. , Soares Magalhães Ricardo J. , Alati Rosa 
Published: May 2018

AbstractRespiratory infections among infants constitute a major burden to health care systems in developed nations, yet the course and risk factors leading to these conditions are poorly understood. We examine the longitudinal patterns of respiratory infection hospitalisation (RIH) and how these patterns are influenced by neonatal pulmonary morbidities. We included all live births (n = 429 058) occurring in the Australian state of Queensland between January 2009 and December 2015. Data were structured so that each participant had a record (present/absent) of RIH for each month from birth to 12 months. Initially, latent class growth analysis was used to identify the trajectories of RIH adjusted for spatial–temporal factors; using the identified trajectories of RIH as outcomes, we built a multinomial logistic regression model to identify neonatal predictors of RIH trajectories. Our results indicated that a four-class solution was the best fit to the data, comprising a ‘no-risk’ trajectory, a ‘low-risk’ trajectory, an ‘early-risk’ trajectory and a ‘chronic-risk’ trajectory. Compared with the no-risk trajectory, membership in the other trajectories was predicted by a range of neonatal pulmonary morbidities, with transient tachypnoea of newborn showing a specific relationship with the early-risk group and sleep apnoea showing a specific and strong risk with the chronic-risk group. Our findings suggest the possibility of identifying neonates at risk of recurrent RIH and implementing effective intervention strategies prior to neonatal discharge.
PRÁCTICAS FUNERARIAS DIFERENCIALES Y POSICIÓN SOCIAL DE LOS NIÑOS EN DOS UNIDADES DOMÉSTICAS DE MONTE ALBÁN, OAXACA
Authors: Márquez Morfín Lourdes , González-Licón Ernesto 
Published: May 2018

AbstractLos habitantes de Monte Albán estaban organizados en una sociedad jerárquica compleja; la integración a la sociedad estuvo determinada por factores sociales, económicos, políticos, así como de género y edad. El objetivo central del estudio radica en identificar la posición social de los niños y su integración como miembros de la comunidad. Con este fin analizamos los patrones funerarios y el uso del espacio en dos unidades domésticas de estatus medio/alto del periodo clásico (200–750 d.C.). De acuerdo con el análisis e interpretación de los resultados, los niños más pequeños fueron enterrados en los patios centrales, algunos en fosas y otros sobre cajetes cubiertos con otro plato. A partir de los cuatro a cinco años se inhumaban bajo el piso de los cuartos y sólo unos cuantos al interior de la tumba familiar. Esta metodología permite conocer las diferencias sociales y de género al interior del grupo social y quizá como reflejo también en la sociedad zapoteca.
ON THE RECORD ABOUT WALT TAYLOR: A PERSONAL ACCOUNT
Authors: Mountjoy Joseph B. 
Published: May 2018

AbstractWalter W. Taylor, especially through his 1948 monograph A Study of Archeology, has been a major influence on the theory and methods of American archaeology. His contribution has recently been assessed in a book by a number of students and colleagues, but none of them had first-hand experience with Walt in a fieldwork setting. This is an account of personal experiences with Walt Taylor, beginning in the graduate program at Southern Illinois University (SIU), but focused on a summer National Science Foundation (NSF) project in Zacatecas in 1964 that was designed to study Chalchihuites/Chichimec interactions in a frontier area, and what that fieldwork experience revealed about Walt Taylor as an archaeologist and as a person.
Accelerated nutrition transition in the North West Province of South Africa: results from the Prospective Urban and Rural Epidemiology (PURE-NWP-SA) cohort study, 2005 to 2010
Authors: Wentzel-Viljoen Edelweiss , Lee Sarie , Laubscher Ria , Vorster Hester H 
Published: May 2018

AbstractObjectiveSouth Africa (SA) is in the midst of a health transition characterized by a quadruple burden of diseases and a nutrition transition. The existing nutrition transition in SA, accompanied by the coexistence of under- and overnutrition in the population, motivated the present study. Its objectives were to measure and report the changes in nutrient intakes of rural and urban black Africans over time to assess the impact of urbanization and modernization of lifestyles on dietary intakes and non-communicable disease (NCD) risk.DesignThe PURE-NWP-SA study recruited 2000 black South African volunteers aged 35–70 years in 2005, of which detailed nutrient intakes from 1858 participants were available. In 2010 nutrient intakes of a cohort of 1154 participants were measured.ResultsMedian energy intake increased over time. In 2010, rural participants consumed the amount of energy (men 9·7 MJ/d; women 9·1 MJ/d) that urban participants consumed in 2005 (men 9·9 MJ/d; women 9·0 MJ/d). The nutrition transition was characterized by increases in the percentage of energy from animal protein, total fat (rural men and women), saturated (not urban women) and monounsaturated fat, as well as added sugar. Despite the higher energy intake, not all the participants met total micronutrient needs in 2010.ConclusionsThe PURE nutrient intake data confirmed that the nutrition transition in the North West Province of SA is extremely rapid in rural areas. The shift towards higher energy intakes, an animal food-based diet, higher intakes of fat and lower intake of fibre, at the cost of lower plant protein and starchy food intakes, could increase the risk of NCD.
Validating fatty acid intake as estimated by an FFQ: how does the 24 h recall perform as reference method compared with the duplicate portion?
Authors: Trijsburg Laura , de Vries Jeanne HM , Hollman Peter CH , Hulshof Paul JM , van ’t Veer Pieter , Boshuizen Hendriek C , Geelen Anouk 
Published: May 2018

AbstractObjectiveTo compare the performance of the commonly used 24 h recall (24hR) with the more distinct duplicate portion (DP) as reference method for validation of fatty acid intake estimated with an FFQ.DesignIntakes of SFA, MUFA, n-3 fatty acids and linoleic acid (LA) were estimated by chemical analysis of two DP and by on average five 24hR and two FFQ. Plasma n-3 fatty acids and LA were used to objectively compare ranking of individuals based on DP and 24hR. Multivariate measurement error models were used to estimate validity coefficients and attenuation factors for the FFQ with the DP and 24hR as reference methods.SettingWageningen, the Netherlands.SubjectsNinety-two men and 106 women (aged 20–70 years).ResultsValidity coefficients for the fatty acid estimates by the FFQ tended to be lower when using the DP as reference method compared with the 24hR. Attenuation factors for the FFQ tended to be slightly higher based on the DP than those based on the 24hR as reference method. Furthermore, when using plasma fatty acids as reference, the DP showed comparable to slightly better ranking of participants according to their intake of n-3 fatty acids (0·33) and n-3:LA (0·34) than the 24hR (0·22 and 0·24, respectively).ConclusionsThe 24hR gives only slightly different results compared with the distinctive but less feasible DP, therefore use of the 24hR seems appropriate as the reference method for FFQ validation of fatty acid intake.
Neural Network Emulation of Reionization Simulations
Authors: Schmit Claude J. , Pritchard Jonathan R. 
Published: May 2018

AbstractNext generation radio experiments such as LOFAR, HERA and SKA are expected to probe the Epoch of Reionization and claim a first direct detection of the cosmic 21cm signal within the next decade. One of the major challenges for these experiments will be dealing with enormous incoming data volumes. Machine learning is key to increasing our data analysis efficiency. We consider the use of an artificial neural network to emulate 21cmFAST simulations and use it in a Bayesian parameter inference study. We then compare the network predictions to a direct evaluation of the EoR simulations and analyse the dependence of the results on the training set size. We find that the use of a training set of size 100 samples can recover the error contours of a full scale MCMC analysis which evaluates the model at each step.
The Square Kilometre Array Epoch of Reionisation and Cosmic Dawn Experiment
Authors: Trott Cathryn M. 
Published: May 2018

AbstractThe Square Kilometre Array (SKA) Epoch of Reionisation and Cosmic Dawn (EoR/CD) experiments aim to explore the growth of structure and production of ionising radiation in the first billion years of the Universe. Here I describe the experiments planned for the future low-frequency components of the Observatory, and work underway to define, design and execute these programs.
Status of Foreground and Instrument Challenges for 21cm EoR experiments – Design Strategies for SKA and HERA
Authors: Thyagarajan Nithyanandan 
Published: May 2018

AbstractDirect detection of the Epoch of Reionization (EoR) via redshifted 21 cm line of H i will reveal the nature of the first stars and galaxies as well as revolutionize our understanding of a poorly explored evolutionary phase of the Universe. Projects such as the MWA, LOFAR, and PAPER commenced in the last decade with the promise of high significance statistical detection of the EoR, but have so far only weakly constrained models owing to unforeseen challenges from bright foreground sources and instrument systematics. It is essential for next generation instruments like the HERA and SKA to have these challenges addressed. I present an analysis of these challenges – wide-field measurements, antenna beam chromaticity, reflections in the instrument, and antenna position errors – along with performance specifications and design solutions that will be critical to designing successful next-generation instruments in enabling the first detection and also in placing meaningful constraints on reionization models.
Spatial distribution of the gamma-ray bursts at very high redshift
Authors: Mészáros Attila 
Published: May 2018

AbstractThe author - with his collaborators - already in years 1995-96 have shown - purely from the analyses of the observations - that the gamma-ray bursts (GRBs) can be till redshift 20. Since that time several other statistical studies of the spatial distribution of GRBs were provided. Remarkable conclusions concerning the star-formation rate and the validity of the cosmological principle were obtained about the regions of the cosmic dawn. In this contribution these efforts are surveyed.
Results From PAPER/HERA
Authors: Pober Jonathan C. 
Published: May 2018

AbstractThe Precision Array for Probing the Epoch of Reionization (PAPER) was a first-generation 21 cm cosmology experiment with the specific goal of detecting the power spectrum of the 21 cm emission from the Epoch of Reionization. Analysis of PAPER data is still ongoing, but lessons learned from PAPER to date have played a critical role in designing the next-generation Hydrogen Epoch of Reionization Array (HERA) experiment. This article reviews five key design choices made by PAPER: use of a non-imaging configuration, redundancy, short baselines, small antenna elements, and a large instantaneous bandwidth. We describe the impact of these choices and the role they played in designing HERA.
Formation of the First Stars and Blackholes
Authors: Yoshida Naoki 
Published: May 2018

AbstractCosmic reionization is thought to be initiated by the first generation of stars and blackholes. We review recent progress in theoretical studies of early structure formation. Cosmic structure formation is driven by gravitational instability of primeval density fluctuations left over from Big Bang. At early epochs, there are baryonic streaming motions with significant relative velocity with respect to dark matter. The formation of primordial gas clouds is typically delayed by the streaming motions, but then physical conditions for the so-called direct collapse blackhole formation are realized in proto-galactic halos. We present a promising model in which intermediate mass blackholes are formed as early as z = 30.
Quasars at the Cosmic Dawn: effects on Reionization properties in cosmological simulations
Authors: Garaldi Enrico , Compostella Michele , Porciani Cristiano 
Published: May 2018

AbstractWe study a model of cosmic reionization where quasars (QSOs) are the dominant source of ionizing photons at all relevant epochs. We employ a suite of adaptive hydrodynamical simulations post-processed with a multi-wavelength Monte Carlo radiative-transfer code and calibrate them in order to accurately reproduce the observed quasar luminosity function and emissivity evolution. Our results show that the QSO-only model fails in reproducing key observables linked to the Helium reionization, as the temperature evolution of the inter-galactic medium (IGM) and the HeII effective optical depth in synthetic Lyα spectra. Nevertheless, we find hints that an increased quasar contribution can explain recent measurements of a large inhomogeneity in the IGM at redshift z ≈ 5. Finally, we devise a method capable of constraining the QSOs contribution to the reionization from the properties of the HeII Lyα forest at z ≈ 3.5.
Galactic neutral hydrogen and the magnetic ISM foreground
Authors: Clark S.E. 
Published: May 2018

AbstractThe interstellar medium is suffused with magnetic fields, which inform the shape of structures in the diffuse gas. Recent high-dynamic range observations of Galactic neutral hydrogen, combined with novel data analysis techniques, have revealed a deep link between the morphology of neutral gas and the ambient magnetic field. At the same time, an observational revolution is underway in low-frequency radio polarimetry, driven in part by the need to characterize foregrounds to the cosmological 21-cm signal. A new generation of experiments, capable of high angular and Faraday depth resolution, are revealing complex filamentary structures in diffuse polarization. The relationship between filamentary structures observed in radio-polarimetric data and those observed in atomic hydrogen is not yet well understood. Multiwavelength observations will enable new insights into the magnetic interstellar medium across phases.
The structure of the ISM in the Zone of Avoidance by high-resolution multi-wavelength observations
Authors: Tóth L. V. , Doi Y. , Pinter S. , Kovács T. , Zahorecz S. , Bagoly Z. , Balázs L. G. , Horvath I. , Racz I. I. , Onishi T. 
Published: May 2018

AbstractWe estimate the column density of the Galactic foreground interstellar medium (GFISM) in the direction of extragalactic sources. All-sky AKARI FIS infrared sky survey data might be used to trace the GFISM with a resolution of 2 arcminutes. The AKARI based GFISM hydrogen column density estimates are compared with similar quantities based on HI 21cm measurements of various resolution and of Planck results. High spatial resolution observations of the GFISM may be important recalculating the physical parameters of gamma-ray burst (GRB) host galaxies using the updated foreground parameters.
Foreground Subtraction and Signal reconstruction in redshifted 21cm Global Signal Experiments using Artificial Neural Networks
Authors: Choudhury Madhurima , Datta Abhirup 
Published: May 2018

AbstractObservations of HI 21cm transition line is a promising probe into the Dark Ages and Epoch-of-Reionization. Detection of this redshifted 21cm signal is one of the key science goal for several upcoming low-frequency radio telescopes like HERA, SKA and DARE. Other global signal experiments include EDGES, LEDA, BIGHORNS, SCI-HI, SARAS. One of the major challenges for the detection of this signal is the accuracy of the foreground source removal. Several novel techniques have been explored already to remove bright foregrounds from both interferometric as well as total power experiments. Here, we present preliminary results from our investigation on application of ANN to detect 21cm global signal amidst bright galactic foreground. Following the formalism of representing the global 21cm signal by ’tanh’ model, this study finds that the global 21cm signal parameters can be accurately determined even in the presence of bright foregrounds represented by 3rd order log-polynomial or higher.
Robust Foregrounds Removal for 21-cm Experiments
Authors: Mertens F. , Ghosh A. , Koopmans L. V. E. 
Published: May 2018

AbstractDirect detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will need to detect the weak 21-cm signal over foregrounds several order of magnitude greater. This requires accurate modeling of the galactic and extragalactic emission and of its contaminants due to instrument chromaticity, ionosphere and imperfect calibration. To solve for this complex modeling, we propose a new method based on Gaussian Process Regression (GPR) which is able to cleanly separate the cosmological signal from most of the foregrounds contaminants. We also propose a new imaging method based on a maximum likelihood framework which solves for the interferometric equation directly on the sphere. Using this method, chromatic effects causing the so-called “wedge” are effectively eliminated (i.e. deconvolved) in the cylindrical (k⊥, k∥) power spectrum.
The Galactic interstellar medium: foregrounds and star formation
Authors: Miville-Deschênes Marc-Antoine 
Published: May 2018

AbstractThis review presents briefly two aspects of Galactic interstellar medium science that seem relevant for studying EoR. First, we give some statistical properties of the Galactic foreground emission in the diffuse regions of the sky. The properties of the emission observed in projection on the plane of the sky are then related to how matter is organised along the line of sight. The diffuse atomic gas is multi-phase, with dense filamentary structures occupying only about 1% of the volume but contributing to about 50% of the emission. The second part of the review presents aspect of structure formation in the Galactic interstellar medium that could be relevant for the subgrid physics used to model the formation of the first stars.