bluuebunny/crossref_metadata_2025_split huggingface dataset:
Challenging the lichen concept:Turgidosculum ulvae(Verrucariaceae) represents an independent photobiont shift to a multicellular blade-like alga
Authors: PÉREZ-ORTEGA Sergio , MILLER Kathy Ann , DE LOS RÍOS Asunción 
Published: May 2018

AbstractSome definitions of the term ‘lichen’ have often emphasized the role of the mycobiont as exhabitant in the symbiosis.Mastodia tessellataandTurgidosculum ulvae, both forming lichen-like associations with foliose algae, have traditionally defied that definition. In this study, we delve into the poorly known association ofT. ulvaewithBlidingia minima. Using four molecular markers (nrLSU, nrSSU,RPB1, mtSSU) we show thatT. ulvaeis a member of the familyVerrucariaceae, closely related to the marine speciesVerrucaria ditmarsica. The presence of bitunicate asci and single-cell ascospores is confirmed. Our analysis of a fragment of therbcL marker demonstrates that the photosynthetic partner belongs toB. minima, although relationships within this taxon remain unclear. Transmission electron microscopy allowed us to illustrate howT. ulvaeinteracts withBlidingiacells, and how haustoria in that species differ from those previously investigated in other marine lichen-forming fungi.
Historical biogeography of the lichenized fungal genusHypotrachyna(Parmeliaceae, Ascomycota): insights into the evolutionary history of a pantropical clade
Authors: CUBAS Paloma , LUMBSCH H. Thorsten , DEL PRADO Ruth , FERENCOVA Zuzana , HLADUN Nestor L. , RICO Victor J. , DIVAKAR Pradeep K. 
Published: May 2018

AbstractHypotrachynais a speciose genus of primarily tropical and oceanic lichen-forming fungi. It includes species with distinct distribution patterns, such as pantropical, restricted and disjunct species. We used a dataset of mitochondrial SSU, nuclear ITS and LSU ribosomal DNA from 89 specimens to study the historical biogeography of the genus. We employed Bayesian and maximum likelihood approaches for phylogenetic analyses, a likelihood-based approach to ancestral area estimation, and a Bayesian approach to estimate divergence times of major lineages within the genus based on molecular evolutionary rates for ITS and a secondary calibration point at theHypotrachynaclade –Parmeliopsissplit. Our analyses suggest that the genus might have originated in the Neotropics during the Eocene and that the split of major lineages happened primarily during the Eocene and Oligocene. The major diversification within those clades is estimated to have occurred during the Miocene. Pantropical species distributions are explained by long-distance dispersal. A number of currently accepted species were found to be non-monophyletic, illustrating that the delimitation of species in the genus needs attention.
Best practice assessment of disease modelling for infectious disease outbreaks
Authors: Dembek Z. F. , Chekol T. , Wu A. 
Published: May 2018

AbstractDuring emerging disease outbreaks, public health, emergency management officials and decision-makers increasingly rely on epidemiological models to forecast outbreak progression and determine the best response to health crisis needs. Outbreak response strategies derived from such modelling may include pharmaceutical distribution, immunisation campaigns, social distancing, prophylactic pharmaceuticals, medical care, bed surge, security and other requirements. Infectious disease modelling estimates are unavoidably subject to multiple interpretations, and full understanding of a model's limitations may be lost when provided from the disease modeller to public health practitioner to government policymaker. We review epidemiological models created for diseases which are of greatest concern for public health protection. Such diseases, whether transmitted from person-to-person (Ebola, influenza, smallpox), via direct exposure (anthrax), or food and waterborne exposure (cholera, typhoid) may cause severe illness and death in a large population. We examine disease-specific models to determine best practices characterising infectious disease outbreaks and facilitating emergency response and implementation of public health policy and disease control measures.
DictumonDicta:Obiter Dictain WTO Disputes
Authors: GAO HENRY 
Published: May 2018

AbstractThis paper discusses an important legal issue raised by the United States in its recent attempt to block the reappointment of an Appellate Body member. According to the US, in some of his decisions, the member has made overreaching findings that amount to obiter dicta. As obiter dictum is a unique concept in the Common Law system, the US argument may only stand if the concept may be found in the WTO legal system as well. With a careful analysis of the concept of dicta in Common Law and a close examination of the effects of past panel and Appellate Body decisions in WTO dispute settlement, the paper rejects the US argument by refuting each of the three premises of the US argument, i.e., the WTO legal system based on Common Law; WTO follows stare decisis; and the WTO has rules against dicta. In addition to original contributions on the nature of the WTO dispute settlement system in theory, the article also provides some practical advice on how the controversy may be resolved.
How Much Market Access? A Case Study of Jordan's Exports to the EU
Authors: BRUNELIN STEPHANIE , DE MELO JAIME , PORTUGAL-PEREZ ALBERTO 
Published: May 2018

AbstractThe value of preferential market access schemes has fallen sharply. Drawing on a relaxation announcement of July 2016 simplifying origin requirements for access to the EU that should help improve market access, thereby contributing to alleviate the refugee crisis in Jordan, this paper argues that a simplification of origin requirements is a straightforward way to enhance preferential market access. Yet, the EU decision limits the beneficiaries who must be located in designated special economic zones, which limits preferential market access. The paper compares the performance of Jordanian exports to the EU and the US under their respective FTAs. It shows that Jordanian exports to the US have grown more rapidly than exports to the EU over the last 15 years. The study documents lower utilisation of preferences in the EU than in the US, especially in Textiles and Apparel (T&A) in spite of non-negligible preferences. Three contributing factors are identified: (i) higher adjusted preferences for apparel in the US than in the EU; (ii) greater competition from other suppliers (mostly from LDCs) in the EU market than in the US market; (iii) simpler origin requirements in the case of the Jordan–US FTA. Comparative evidence from the two FTAs and econometric estimates suggest that this should help restore market access for Jordanian exports to the EU. These estimates provide additional evidence that origin requirements suppress market access. Other pathways to simplify origin requirements are offered in the conclusion.
Neutral hydrogen in the post-reionization universe
Authors: Padmanabhan Hamsa 
Published: May 2018

AbstractThe evolution of neutral hydrogen (HI) across redshifts is a powerful probe of cosmology, large scale structure in the universe and the intergalactic medium. Using a data-driven halo model to describe the distribution of HI in the post-reionization universe (z ∼ 5 to 0), we obtain the best-fitting parameters from a rich sample of observational data: low redshift 21-cm emission line studies, intermediate redshift intensity mapping experiments, and higher redshift Damped Lyman Alpha (DLA) observations. Our model describes the abundance and clustering of neutral hydrogen across redshifts 0 - 5, and is useful for investigating different aspects of galaxy evolution and for comparison with hydrodynamical simulations. The framework can be applied for forecasting future observations with neutral hydrogen, and extended to the case of intensity mapping with molecular and other line transitions at intermediate redshifts.
Simultaneously constraining the astrophysics of reionisation and the epoch of heating with 21CMMC
Authors: Greig Bradley , Mesinger Andrei 
Published: May 2018

AbstractWe extend our MCMC sampler of 3D EoR simulations, 21CMMC, to perform parameter estimation directly on light-cones of the cosmic 21cm signal. This brings theoretical analysis one step closer to matching the expected 21-cm signal from next generation interferometers like HERA and the SKA. Using the light-cone version of 21CMMC, we quantify biases in the recovered astrophysical parameters obtained from the 21cm power spectrum when using the co-eval approximation to fit a mock 3D light-cone observation. While ignoring the light-cone effect does not bias the parameters under most assumptions, it can still underestimate their uncertainties. However, significant biases (∼few – 10 σ) are possible if all of the following conditions are met: (i) foreground removal is very efficient, allowing large physical scales (k ∼ 0.1 Mpc−1) to be used in the analysis; (ii) theoretical modelling is accurate to ∼10 per cent in the power spectrum amplitude; and (iii) the 21cm signal evolves rapidly (i.e. the epochs of reionisation and heating overlap significantly
New simulation of QSO X-ray heating during the Cosmic Dawn
Authors: Ross Hannah E. , Dixon Keri , Iliev Ilian , Mellema Garrelt 
Published: May 2018

AbstractThe upcoming radio interferometer Square Kilometre Array is expected to directly detect the redshifted 21-cm signal from the Cosmic Dawn for the first time. In this era temperature fluctuations from X-ray heating of the neutral intergalactic medium can impact this signal dramatically. Previously, in Ross et al. (2017), we presented the first large-volume, 244 h-1 Mpc=349 Mpc a side, fully numerical radiative transfer simulations of X-ray heating. This work is a follow-up where we now also consider QSO-like sources in addition to high mass X-ray binaries. Images of the two cases are clearly distinguishable at SKA1-LOW resolution and have RMS fluctuations above the expected noise. The inclusion of QSOs leads to a dramatic increase in non-Gaussianity of the signal, as measured by the skewness and kurtosis of the 21-cm signal. We conclude that this increased non-Gaussianity is a promising signature of early QSOs.
Evolution of the Quasar Luminosity Function: Implications for EoR-21cm
Authors: Kulkarni Girish , Choudhury Tirthankar Roy , Puchwein Ewald , Haehnelt Martin G. 
Published: May 2018

AbstractWe present predictions for the spatial distribution of 21 cm brightness temperature fluctuations from high-dynamic-range simulations for AGN-dominated reionization histories that have been tested against available Lyα and CMB data. We model AGN by extrapolating the observed Mbh–σ relation to high redshifts and assign them ionizing emissivities consistent with recent UV luminosity function measurements. AGN-dominated reionization histories increase the variance of the 21 cm emission by a factor of up to ten compared to similar reionization histories dominated by faint galaxies, to values close to 100 mK2 at scales accessible to experiments (k ≲ 1 cMpc−1h). This is lower than the sensitivity reached by ongoing experiments by only a factor of about two or less. AGN dominated reionization should be easily detectable by LOFAR (and later HERA and SKA1) at their design sensitivity.
A Clustered Extragalactic Foreground Model for the EoR
Authors: Murray S. G. , Trott C. M. , Jordan C. H. 
Published: May 2018

AbstractWe review an improved statistical model of extra-galactic point-source foregrounds first introduced in Murray et al. (2017), in the context of the Epoch of Reionization. This model extends the instrumentally-convolved foreground covariance used in inverse-covariance foreground mitigation schemes, by considering the cosmological clustering of the sources. In this short work, we show that over scales of k ∼ (0.6, 40.)hMpc−1, ignoring source clustering is a valid approximation. This is in contrast to Murray et al. (2017), who found a possibility of false detection if the clustering was ignored. The dominant cause for this change is the introduction of a Galactic synchrotron component which shadows the clustering of sources.
The Zone of Avoidance as an X-ray absorber - the role of the galactic foreground modelling Swift XRT spectra
Authors: Racz I. I. , Bagoly Z. , Tóth L. V. , Balázs L. G. , Horvath I. , Zahorecz S. 
Published: May 2018

AbstractGamma-ray bursts (GRBs) are the most powerful explosive events in the Universe. The prompt gamma emission is followed by an X-ray afterglow that is also detected for over nine hundred GRBs by the Swift BAT and XRT detectors. The X-ray afterglow spectrum bears essential information about the burst, and the surrounding interstellar medium (ISM). Since the radiation travels through the line of sight intergalactic medium and the ISM in the Milky Way, the observed emission is influenced by extragalactic and galactic components. The column density of the Galactic foreground ranges several orders of magnitudes, due to both the large scale distribution of ISM and its small scale structures. We examined the effect of local HI column density on the penetrating X-ray emission, as the first step towards a precise modeling of the measured X-ray spectra. We fitted the X-ray spectra using the Xspec software, and checked how the shape of the initially power low spectrum changes with varying input Galactic HI column density. The total absorbing HI column is a sum of the intrinsic and Galactic component. We also investigated the model results for the intrinsic component varying the Galactic foreground. We found that such variations may alter the intrinsic hydrogen column density up to twenty-five percent. We will briefly discuss its consequences.
MWA Observations of the EOR1 Field
Authors: Pindor Bart 
Published: May 2018

AbstractThe EOR1 field at (RA,DEC)=(4hrs, −30.0°) is one of the main targets of the MWA EOR experiment. It is notable for being in one of the coldest regions of the southern radio sky, as well as for containing the bright radio galaxy Fornax A. We report an early demonstration that the distance of this field from the Galactic Centre may make it a prime field for EOR observations.
The Neutral Islands during the Late Epoch of Reionization
Authors: Xu Yidong , Yue Bin , Chen Xuelei 
Published: May 2018

AbstractThe large-scale structure of the ionization field during the epoch of reionization (EoR) can be modeled by the excursion set theory. While the growth of ionized regions during the early stage are described by the “bubble model”, the shrinking process of neutral regions after the percolation of the ionized region calls for an “island model”. An excursion set based analytical model and a semi-numerical code (islandFAST) have been developed. The ionizing background and the bubbles inside the islands are also included in the treatment. With two kinds of absorbers of ionizing photons, i.e. the large-scale under-dense neutral islands and the small-scale over-dense clumps, the ionizing background are self-consistently evolved in the model.
Extragalactic optical and near-infrared foregrounds to 21-cm epoch of reionisation experiments
Authors: Jarvis Matt J. , Bowler Rebecca A.A. , Hatfield Peter W. 
Published: May 2018

AbstractForeground contamination is one of the most important limiting factors in detecting the neutral hydrogen in the epoch of reionisation. These foregrounds can be roughly split into galactic and extragalactic foregrounds. In these proceedings we highlight information that can be gleaned from multi-wavelength extragalactic surveys in order to overcome this issue. We discuss how clustering information from the lower-redshift, foreground galaxies, can be used as additional information in accounting for the noise associated with the foregrounds. We then go on to highlight the expected contribution of future optical and near-infrared surveys for detecting the galaxies responsible for ionising the Universe. We suggest that these galaxies can also be used to reduce the systematics in the 21-cm epoch of reionisation signal through cross-correlations if enough common area is surveyed.
The Responses of Forest Fine Root Biomass/Necromass Ratio to Environmental Factors Depend on Mycorrhizal Type and Latitudinal Region
Authors: Wang Cunguo , Chen Zhao , Yin Hong , Guo Wei , Cao Ying , Wang Guojiao , Sun Bei , Yan Xuefei , Li Jiandong , Zhao Tian‐Hong , Brunner Ivano , Dai Guanhua , Zheng Yixiang , Zheng Yiguo , Zu Weizhong , Li Mai‐He 
Published: May 2018

AbstractFine root (≤2 mm in diameter) biomass/necromass (B/N) ratio, representing many dynamic key root parameters, can serve as a powerful measure of root vitality. Based on a global synthesis of fine root biomass and necromass in forest ecosystems, we describe a framework for recognizing responses of B/N ratio to biotic (e.g., mycorrhizal type) and abiotic (e.g., latitudinal region) characteristics. Arbuscular mycorrhiza (AM) and ectomycorrhiza (ECM) forests had similar average B/N ratios (3.28 versus 3.23). AM forest B/N ratio decreased with increasing altitude, stand density, tree age, and soil carbon/nitrogen ratio (C/N) but increased with soil pH. In contrast, ECM forest B/N ratio increased with increasing mean annual precipitation (MAP), altitude, and stand density but decreased with tree age. The average B/N ratio was higher in temperate forests (4.39) than in tropical (2.97) and boreal forests (2.40). The B/N ratio was relatively stable in temperate forests irrespective of changes in biotic and abiotic factors. In tropical forest, the B/N ratio was sensitive to mean annual temperature, altitude, soil C/N ratio, and pH, whereas in boreal forests, it was more sensitive to MAP, stand density, and tree age. The late‐successional forest B/N ratio was closely aligned with biotic and abiotic factors. Our analysis revealed that the relationships of B/N ratio with climate, topography, edaphic, and stand characteristics were dependent on mycorrhizal types and latitudinal regions. These findings provide a basis for large‐scale prediction of fine root dynamics and for better understanding of belowground processes of global forest ecosystems in a changing world.
Asynchronous evolution of interdependent nest characters across the avian phylogeny
Authors: Fang Yi-Ting , Tuanmu Mao-Ning , Hung Chih-Ming 
Published: May 2018

AbstractNest building is a widespread behavior among birds that reflects their adaptation to the environment and evolutionary history. However, it remains unclear how nests evolve and how their evolution relates to the bird phylogeny. Here, by examining the evolution of three nest characters—structure, site, and attachment—across all bird families, we reveal that nest characters did not change synchronically across the avian phylogeny but had disparate evolutionary trajectories. Nest structure shows stronger phylogenetic signal than nest site, while nest attachment has little variation. Nevertheless, the three characters evolved interdependently. For example, the ability of birds to explore new nest sites might depend on the emergence of novel nest structure and/or attachment. Our results also reveal labile nest characters in passerines compared with other birds. This study provides important insights into avian nest evolution and suggests potential associations between nest diversification and the adaptive radiations that generated modern bird lineages.
Instability of the Northeast Greenland Ice Stream over the last 45,000 years
Authors: Larsen Nicolaj K. , Levy Laura B. , Carlson Anders E. , Buizert Christo , Olsen Jesper , Strunk Astrid , Bjørk Anders A. , Skov Daniel S. 
Published: May 2018

AbstractThe sensitivity of the Northeast Greenland Ice Stream (NEGIS) to prolonged warm periods is largely unknown and geological records documenting such long-term changes are needed to place current observations in perspective. Here we use cosmogenic surface exposure and radiocarbon ages to determine the magnitude of NEGIS margin fluctuations over the last 45 kyr (thousand years). We find that the NEGIS experienced slow early Holocene ice-margin retreat of 30–40 m a−1, likely as a result of the buttressing effect of sea-ice or shelf-ice. The NEGIS was ~20–70 km behind its present ice-extent ~41–26 ka and ~7.8–1.2 ka; both periods of high orbital precession index and/or summer temperatures within the projected warming for the end of this century. We show that the NEGIS was smaller than present for approximately half of the last ~45 kyr and is susceptible to subtle changes in climate, which has implications for future stability of this ice stream.
Outlier response to anti-PD1 in uveal melanoma reveals germline MBD4 mutations in hypermutated tumors
Authors: Rodrigues Manuel , Mobuchon Lenha , Houy Alexandre , Fiévet Alice , Gardrat Sophie , Barnhill Raymond L. , Popova Tatiana , Servois Vincent , Rampanou Aurore , Mouton Aurore , Dayot Stéphane , Raynal Virginie , Galut Michèle , Putterman Marc , Tick Sarah , Cassoux Nathalie , Roman-Roman Sergio , Bidard François-Clément , Lantz Olivier , Mariani Pascale , Piperno-Neumann Sophie , Stern Marc-Henri 
Published: May 2018

AbstractMetastatic uveal melanoma is a deadly disease with no proven standard of care. Here we present a metastatic uveal melanoma patient with an exceptional high sensitivity to a PD-1 inhibitor associated with outlier CpG>TpG mutation burden, MBD4 germline deleterious mutation, and somatic MBD4 inactivation in the tumor. We identify additional tumors in The Cancer Genome Atlas (TCGA) cohorts with similar hypermutator profiles in patients carrying germline deleterious MBD4 mutations and somatic loss of heterozygosity. This MBD4-related hypermutator phenotype may explain unexpected responses to immune checkpoint inhibitors.
Multiscale nanowire-microfluidic hybrid strain sensors with high sensitivity and stretchability
Authors: Han Songjia , Liu Chunrui , Xu Huihua , Yao Dongyuan , Yan Kanghong , Zheng Huanliang , Chen Hui-Jiuan , Gui Xuchun , Chu Sheng , Liu Chuan 
Published: May 2018

AbstractNanomaterials with low-dimensional morphology have been explored for enhancing the performance of strain sensors, but it remains difficult to achieve high stretchability and sensitivity simultaneously. In this work, a composite structure strain sensor based on nanomaterials and conductive liquid is designed, demonstrated, and engineered. The nanowire-microfluidic hybrid (NMH) strain sensor responds to multiscale strains from 4% to over 400%, with a high sensitivity and durability under small strain. Metal nanowires and carbon nanotubes are used to fabricate the NMH strain sensors, which simultaneously exhibit record-high average gauge factors and stretchability, far better than the conventional nanowire devices. Quantitative modeling of the electrical characteristics reveals that the effective conductivity percolation through the hybrid structures is the key to achieving high gauge factors for multiscale sensing. The sensors can operate at low voltages and are capable of responding to various mechanical deformations. When fixed on human skin, the sensors can monitor large-scale deformations (skeleton motion) and small-scale deformations (facial expressions and pulses). The sensors are also employed in multichannel, interactive electronic system for wireless control of robotics. Such demonstrations indicate the potential of the sensors as wearable detectors for human motion or as bionic ligaments in soft robotics.