We present the analysis of the restframe optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at z = 3.911. The spectroscopic data were taken with the ...optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between C III λ1910 and O III λλ4959,5007. We have investigated the possible presence of multiple BALs by computing “balnicity” and absorption indexes (i.e., BI, BI0, and AI) for the transitions Si IV λ1400, C IV λ1549, Al III λ1860, and Mg II λ2800. No clear evidence for the presence of absorption features is found in addition to the already known, prominent BAL associated to C IV, which supports a high-ionization BAL classification for APM 08279+5255. We also studied the properties of the O III, Hβ, and Mg II emission lines. We find that O III is intrinsically weak (FOIII∕FHβ ≲ 0.04), as it is typically found in luminous quasars with a strongly blueshifted C IV emission line (~2500 km s−1 for APM 08279+5255). We computed the single-epoch black hole mass based on Mg II and Hβ broad emission lines, finding MBH = (2 ÷ 3) × 1010μ−1 M⊙, with the magnification factor μ that can vary between 4 and 100 according to CO and restframe UV-to-mid-IR imaging respectively. Using a Mg II equivalent width (EW)-to-Eddington ratio relation, the EWMgII ~ 27 Å measured for APM 08279+5255 translates into an Eddington ratio of ~0.4, which is more consistent with μ = 4. This magnification factor also provides a value of MBH that is consistent with recent reverberation-mapping measurements derived from C IV and Si IV.
Dwarf spheroidal galaxies are among the best environments that can be studied with Cherenkov telescopes for indirect searches of
γ
-ray signals coming from dark matter self-interaction (annihilation ...or decay), due to their proximity and negligible background emission. We present new determinations of the dark-matter amount – i.e. the astrophysical factors
J
and
D
– in dwarf-galaxy halos obtained through the MCMC Jeans analysis of their brightness and kinematic data. Such factors are of great importance to test the performances of the next-generation
γ
-ray instruments such as the Cherenkov Telescope Array in detecting dark-matter signals from astronomical environments, or constraining the limits to dark-matter physics parameters (particle mass and lifetime, annihilation cross section).
So far the masses of about 50 active galactic nuclei (AGNs) have been measured through the reverberation mapping technique (RM). Most measurements have been performed for objects of moderate ...luminosity and redshift, based on Hβ, which is also used to calibrate the scaling relation that allows single-epoch (SE) mass determination based on AGN luminosity and the width of different emission lines. Due to the complex structure and gas dynamics of the relevant emission region, the SE masses obtained from the C IV(1549 Å) line show a large spread around the mean values. Direct RM measures of C IV exist for only six AGNs of low luminosity and redshift, and only one luminous quasar. Since 2003, we have collected photometric and spectroscopic observations of PG1247+267, the most luminous quasar ever analyzed for RM. We provide light curves for the continuum and for C IV(1549 Å) and C III(1909 Å), and measures of the reverberation time lags based on the SPEAR method. The sizes of the line emission regions assume a ratio of R {sub C} {sub III}/R {sub C} {sub IV} ∼ 2, similar to the case of Seyfert galaxies, indicating for the first time a similar ionization stratification in a luminous quasar and low-luminosity nuclei. Due to the relatively small size of the broad line region and the relatively narrow line widths, we estimate a small mass and an anomalously high Eddington ratio. We discuss the possibility that either the shape of the emission region or an amplification of the luminosity caused by gravitational lensing may be partly responsible for the result.
Abstract Background The present contribution aims to investigate the motivations underlying blood donation and to probe how these differ on the basis of number of donations and donors' gender. ...Materials and methods A total of 237 Italian donors (64.6% male) were administered a self-report questionnaire containing socio-demographic variables and Omoto and Snyder's Motivations for Volunteerism Scale adapted to blood donation. Results and discussion The results reveal: (a) significant differences between new donors (1–4 donations) and loyal donors (5–15 donations) as well as between new donors and regular donors (more than 16 donations) emerge with respect to social motivations and ego-protection, which increase proportionately to number of donations; (b) gender differences characterize all the motivations except those related to values; (c) value motivations do not vary either with respect to number of donations or to gender.
Abstract
The coincident detection of GW170817 in gravitational waves and electromagnetic radiation spanning the radio to MeV gamma-ray bands provided the first direct evidence that short gamma-ray ...bursts (GRBs) can originate from binary neutron star (BNS) mergers. On the other hand, the properties of short GRBs in high-energy gamma-rays are still poorly constrained, with only ∼20 events detected in the GeV band, and none in the TeV band. GRB 160821B is one of the nearest short GRBs known at
z
= 0.162. Recent analyses of the multiwavelength observational data of its afterglow emission revealed an optical-infrared kilonova component, characteristic of heavy-element nucleosynthesis in a BNS merger. Aiming to better clarify the nature of short GRBs, this burst was automatically followed up with the MAGIC telescopes, starting from 24 s after the burst trigger. Evidence of a gamma-ray signal is found above ∼0.5 TeV at a significance of ∼ 3
σ
during observations that lasted until 4 hr after the burst. Assuming that the observed excess events correspond to gamma-ray emission from GRB 160821B, in conjunction with data at other wavelengths, we investigate its origin in the framework of GRB afterglow models. The simplest interpretation with one-zone models of synchrotron-self-Compton emission from the external forward shock has difficulty accounting for the putative TeV flux. Alternative scenarios are discussed where the TeV emission can be relatively enhanced. The role of future GeV–TeV observations of short GRBs in advancing our understanding of BNS mergers and related topics is briefly addressed.
Respiratory infections are one of the main health problems worldwide. They are a challenging field of study due to an intricate relationship between the pathogenicity of microbes and the host's ...defenses. To better understand mechanisms of respiratory infections, different models have been developed. A model is the reproduction of a disease in a system that mimics human pathophysiology. For this reason, the best models should closely resemble real-life conditions. Thus, the human model is the best. However, human models of respiratory infections have some disadvantages that limit their role. Therefore, other models, including animal, in vitro, and mathematical ones, have been developed. We will discuss advantages and limitations of available models and focus on models of viral infections as triggers of asthma exacerbations, viral infections being one of the most frequent causes of exacerbating disease. Future studies should focus on the interrelation of various models.
Animal pollinators are globally threatened by anthropogenic land use change and agricultural intensification. The yield of many food crops is therefore negatively impacted because they benefit from ...biotic pollination. This is especially the case in the tropics. For instance, fruit set of Coffea arabica has been shown to increase by 10–30% in plantations with a high richness of bee species, possibly influenced by the availability of surrounding forest habitat. Here, we performed a global literature review to (1) assess how much animal pollination enhances coffee fruit set, and to (2) examine the importance of the amount of forest cover, distance to nearby forest and forest canopy density for bee species richness and coffee fruit set. Using a systematic literature review, we identified eleven case studies with a total of 182 samples where fruit set of C. arabica was assessed. We subsequently gathered forest data for all study sites from satellite imagery. We modelled the effects of open (all forest with a canopy density of ≥25%), closed (≥50%) and dense (≥75%) forests on pollinator richness and fruit set of coffee. Overall, we found that animal pollination increases coffee fruit set by ~18% on average. In only one of the case studies, regression results indicate a positive effect of dense forest on coffee fruit set, which increased with higher forest cover and shorter distance to the forest. Against expectations, forest cover and distance to open forest were not related to bee species richness and fruit set. In summary, we provide strong empirical support for the notion that animal pollinators increase coffee fruit set. Forest proximity had little overall influence on bee richness and coffee fruit set, except when farms were surrounded by dense tropical forests, potentially because these may provide high-quality habitats for bees pollinating coffee. We, therefore, advocate that more research is done to understand the biodiversity value of dense forest for pollinators, notably assessing the mechanisms underlying the importance of forest for pollinators and their pollination services.
•In a meta-study, we gathered 11 case studies that assessed fruit set of C. arabica.•We assessed effects of pollinators and forest on coffee fruit set within each study.•Globally, we found that animal pollination increases coffee fruit set by ~18%.•One study indicates that forest with a dense canopy may benefit coffee pollination.•We suggest more research on the biodiversity value of dense forest for pollinators.
Context.
Extended and delayed emission around distant TeV sources induced by the effects of propagation of
γ
ray s through the intergalactic medium can be used for the measurement of the ...intergalactic magnetic field (IGMF).
Aims.
We search for delayed GeV emission from the hard-spectrum TeV
γ
-ray emitting blazar 1ES 0229+200, with the goal of detecting or constraining the IGMF-dependent secondary flux generated during the propagation of TeV
γ
rays through the intergalactic medium.
Methods.
We analysed the most recent MAGIC observations over a 5 year time span, and complemented them with historic data of the H.E.S.S. and VERITAS telescopes, along with a 12-year-long exposure of the
Fermi
/LAT telescope. We used them to trace source evolution in the GeV–TeV band over a decade and a half. We used Monte Carlo simulations to predict the delayed secondary
γ
-ray flux, modulated by the source variability, as revealed by TeV-band observations. We then compared these predictions for various assumed IGMF strengths to all available measurements of the
γ
-ray flux evolution.
Results.
We find that the source flux in the energy range above 200 GeV experiences variations around its average on the 14-year time span of observations. No evidence for the flux variability is found in the 1 − 100 GeV energy range accessible to
Fermi
/LAT. The non-detection of variability due to delayed emission from electromagnetic cascade developing in the intergalactic medium imposes a lower bound of
B
> 1.8 × 10
−17
G for the long-correlation-length IGMF and
B
> 10
−14
G for an IGMF of cosmological origin. Though weaker than the one previously derived from the analysis of
Fermi
/LAT data, this bound is more robust, being based on a conservative intrinsic source spectrum estimate and accounting for the details of source variability in the TeV energy band. We discuss implications of this bound for cosmological magnetic fields that might explain the baryon asymmetry of the Universe.
Substantial evidence in the last few decades suggests that outflows from supermassive black holes (SMBH) may play a significant role in the evolution of galaxies. These outflows, powered by active ...galactic nuclei (AGN), are thought to be the fundamental mechanism by which the SMBH transfers a significant fraction of its accretion energy to the surrounding environment. Large-scale outflows known as warm absorbers (WA) and fast disk winds known as ultra-fast outflows (UFO) are commonly found in the spectra of many Seyfert galaxies and quasars, and a correlation has been suggested between them. Recent detections of low ionization and low column density outflows, but with a high velocity comparable to UFOs, challenge such initial possible correlations. Observations of UFOs in AGN indicate that their energetics may be enough to have an impact on the interstellar medium (ISM). However, observational evidence of the interaction between the inner high-ionization outflow and the ISM is still missing. We present here the spectral analysis of 12 XMM-Newton/EPIC archival observations of the quasar PG 1114+445, aimed at studying the complex outflowing nature of its absorbers. Our analysis revealed the presence of three absorbing structures. We find a WA with velocity v ∼ 530 km s−1, ionization log ξ/erg cm s−1 ∼ 0.35, and column density log NH/cm−2 ∼ 22, and a UFO with vout ∼ 0.145c, log ξ/erg cm s−1 ∼ 4, and log NH/cm−2 ∼ 23. We also find an additional absorber in the soft X-rays (E < 2 keV) with velocity comparable to that of the UFO (vout ∼ 0.120c), but ionization (log ξ/erg cm s−1 ∼ 0.5) and column density (log NH/cm−2 ∼ 21.5) comparable with those of the WA. The ionization, velocity, and variability of the three absorbers indicate an origin in a multiphase and multiscale outflow, consistent with entrainment of the clumpy ISM by an inner UFO moving at ∼15% the speed of light, producing an entrained ultra-fast outflow (E-UFO).
Context
Managing landscapes to increase multiple services provision in search of higher agricultural yield can be an alternative to agricultural intensification. Nonetheless, to properly guide ...management, we need to better understand how landscape structure affects multiple services at different scales.
Objectives
Focused on synergies and trade-offs in real-world landscapes, we investigated how and at which scale landscape features related to the supply, demand and flow of services act as a common driver of pollination and pest control in coffee plantations.
Methods
Considering landscapes in an important coffee-producing region in Brazil, we tested the effects of
forest
and
coffee cover
,
distance to forest
,
forest-coffee edge density
and
coffee edge diversity
at multiple scales on pollination and pest control by birds, bats and ants.
Results
Coffee edge diversity (number of land uses in contact with coffee) was an important driver of pollination and pest control, being consistently relevant at local scales (up to 300 m). However, services were also affected by other landscape features and the ‘scale of effect’ of these relationships varied. Additionally, results show the complex nature of pest control once the direction of effect revealed services and disservices.
Conclusions
Besides reinforcing the importance of known landscape effects, this study adds to previous studies by showcasing the relevance of diverse land uses around coffee crops as a common driver of pollination and pest control provision by different species. Moreover, we highlight how understanding the combined local and landscape effects may aid in offsetting disservices and tackling the variety of ‘scales of effect’ found.
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![C IV AND C III] REVERBERATI...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1538-4357_0004-637X/small "C IV AND C III] REVERBERATION MAPPING OF THE LUMINOUS QUASAR PG 1247+267")
