68 research outputs found
Priority areas for conservation alone are not a good proxy for predicting the impact of renewable energy expansion
Non peer reviewe
Identifying potential areas of expansion for the endangered brown bear (Ursus arctos) population in the cantabrian mountains (NW Spain)
Many large carnivore populations are expanding into human-modified landscapes and the
subsequent increase in coexistence between humans and large carnivores may intensify
various types of conflicts. A proactive management approach is critical to successful mitigation
of such conflicts. The Cantabrian Mountains in Northern Spain are home to the last
remaining native brown bear (Ursus arctos) population of the Iberian Peninsula, which is
also amongst the most severely threatened European populations, with an important core
group residing in the province of Asturias. There are indications that this small population is
demographically expanding its range. The identification of the potential areas of brown bear
range expansion is crucial to facilitate proactive conservation and management strategies
towards promoting a further recovery of this small and isolated population. Here, we used a
presence-only based maximum entropy (MaxEnt) approach to model habitat suitability and
identify the areas in the Asturian portion of the Cantabrian Mountains that are likely to be
occupied in the future by this endangered brown bear population following its range expansion.
We used different spatial scales to identify brown bear range suitability according to different
environmental, topographic, climatic and human impact variables. Our models mainly
show that: (1) 4977 km2 are still available as suitable areas for bear range expansion, which
represents nearly half of the territory of Asturias; (2) most of the suitable areas in the western
part of the province are already occupied (77% of identified areas, 2820 km2), 41.4% of
them occurring inside protected areas, which leaves relatively limited good areas for further
expansion in this part of the province, although there might be more suitable areas in surrounding
provinces; and (3) in the eastern sector of the Asturian Cantabrian Mountains,
62% (2155 km2) of the land was classified as suitable, and this part of the province hosts
44.3% of the total area identified as suitable areas for range expansion. Our results further
highlight the importance of increasing: (a) the connectivity between the currently occupied
western part of Asturias and the areas of potential range expansion in the eastern parts of
the province; and (b) the protection of the eastern sector of the Cantabrian Mountains,
where most of the future population expansion may be expected.S1 Fig. Brown bear occurrence data and location of the study area in Europe.
https://doi.org/10.1371/journal.pone.0209972.s001S2 Fig.
Evaluation metrics for 130 candidate models containing different levels of complexity defined by a range of five feature type combinations including linear (L), quadratic (Q), product (P), threshold (T) and hinge (H) features, each evaluated over a range of regularization multipliers ranging from 0 to 10, for (a) the coarse and (b) fine scales of the distribution of the Cantabrian brown bear in Asturias. Evaluation metrics include delta AICc, which is the difference in AICc (Akaikes Information Criterion corrected for small sample sizes, calculated as the sum of the log transformed raw output penalized by the number of model parameters), AUC test, which is the AUC (area Under the receiving operator characteristics Curve) score for the testing data set, AUC diff, which is the difference in AUC scores between the training and testing data sets, and OR min, which is a threshold dependent statistic corresponds to the proportion of testing localities that have MaxEnt output values lower than the value associated with the training locality with the lowest value.
https://doi.org/10.1371/journal.pone.0209972.s002S3 Fig.
Jacknife evaluations of variable contributions to the (a) coarse and (b) fine scale models. The variables with the highest gain when used in isolation are slope for the coarse scale (a) and forest cover foir the fine scale model (b). These variables therefore seem to have provided the most useful information by themselves for each scale. The variables that decreased the gain most when omitted, and thus possessed the greatest amount of information not present in the other variables, were slope for the coarse scale (a) and population density for the fine scale model (b).
https://doi.org/10.1371/journal.pone.0209972.s003S4 Fig. Output of the coarse scale model with a 5 x 5 km resolution.
The map presents a clog-log transformation of the raw MaxEnt output, which can be interpreted as a probability of brown bear range occurrence.
https://doi.org/10.1371/journal.pone.0209972.s004S5 Fig.
Schematic examples of incremental range expansion (a) out of an initial core area as well as (b) a patchy range expansion were no area is occupied two consecutive years, their nestedness values as well as the association matrices used to calculate nestedness.
https://doi.org/10.1371/journal.pone.0209972.s005S6 Fig. Associations between predicted suitability estimated from the coarse scale model each of the included environmental predictors.
https://doi.org/10.1371/journal.pone.0209972.s006S7 Fig. Associations between predicted suitability estimated from the fine scale model each of the included environmental predictors.
https://doi.org/10.1371/journal.pone.0209972.s007S1 Table. Description, source and original format of the 25 environmental variables initially developed for the construction of the models.
Variables marked with * are the ones not correlated and ultimately used in the modelling.
https://doi.org/10.1371/journal.pone.0209972.s008S2 Table. Variable contribution to the construction of the coarse and fine scale models.
https://doi.org/10.1371/journal.pone.0209972.s009S3 Table. Centre coordinates of the 5 x 5 km grids classed as bear home range used as bear occurrence data in the coarse scale model.
https://doi.org/10.1371/journal.pone.0209972.s010S4 Table. Centre coordinates of the 1 x 1 km grids that contained a bear observation used as bear occurrence data in the fine scale model.
https://doi.org/10.1371/journal.pone.0209972.s011The Gobierno del Principado de Asturias (with FEDER co-financing);
the Spanish Ministry of Economy Industry and Competitiveness ((MINECO);
the Agencia Estatal de InvestigaciĂłn (AEI) and the Fondo Europeo de Desarrollo Regional (FEDER, EU) as well as Ramon & Cajal research contracts from the Spanish Ministry of Economy, Industry and Competitiveness.http://www.plosone.org/pm2020Mammal Research InstituteZoology and Entomolog
Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory
The advent of the Auger Engineering Radio Array (AERA) necessitates the
development of a powerful framework for the analysis of radio measurements of
cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air
shower radio emission in coincidence with the surface particle detectors and
fluorescence telescopes of the Pierre Auger Observatory, the radio analysis
functionality had to be incorporated in the existing hybrid analysis solutions
for fluoresence and surface detector data. This goal has been achieved in a
natural way by extending the existing Auger Offline software framework with
radio functionality. In this article, we lay out the design, highlights and
features of the radio extension implemented in the Auger Offline framework. Its
functionality has achieved a high degree of sophistication and offers advanced
features such as vectorial reconstruction of the electric field, advanced
signal processing algorithms, a transparent and efficient handling of FFTs, a
very detailed simulation of detector effects, and the read-in of multiple data
formats including data from various radio simulation codes. The source code of
this radio functionality can be made available to interested parties on
request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to
author list and references in v
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
The Pierre Auger Collaboration has reported evidence for anisotropy in the
distribution of arrival directions of the cosmic rays with energies
eV. These show a correlation with the distribution
of nearby extragalactic objects, including an apparent excess around the
direction of Centaurus A. If the particles responsible for these excesses at
are heavy nuclei with charge , the proton component of the
sources should lead to excesses in the same regions at energies . We here
report the lack of anisotropies in these directions at energies above
(for illustrative values of ). If the anisotropies
above are due to nuclei with charge , and under reasonable
assumptions about the acceleration process, these observations imply stringent
constraints on the allowed proton fraction at the lower energies
Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory
We present the results of searches for dipolar-type anisotropies in different
energy ranges above eV with the surface detector array of
the Pierre Auger Observatory, reporting on both the phase and the amplitude
measurements of the first harmonic modulation in the right-ascension
distribution. Upper limits on the amplitudes are obtained, which provide the
most stringent bounds at present, being below 2% at 99% for EeV
energies. We also compare our results to those of previous experiments as well
as with some theoretical expectations.Comment: 28 pages, 11 figure
Observation and confirmation of nine strong-lensing systems in Dark Energy Survey Year 1 data
We describe the observation and confirmation of nine new strong gravitational lenses discovered in Year 1 data from the Dark Energy Survey (DES). We created candidate lists based on (i) galaxy group and cluster samples, and (ii) photometrically selected galaxy samples. We selected 46 candidates through visual inspection and then used the Gemini Multi-Object Spectrograph(GMOS) at the Gemini South telescope to acquire a spectroscopic follow-up of 21 of these candidates. Through an analysis of these spectroscopic follow-up data, we confirmed nine new lensing systems and rejected two candidates, and the analysis was inconclusive on 10 candidates. For each of the confirmed systems, our report measured spectroscopic properties, estimated source imageâlens separations, and estimated enclosed masses as well. The sources that we targeted have an i-band surface brightness range of iSBâŒ22â24magarcsecâ2 and a spectroscopic redshift range of zspec ⌠0.8â2.6. The lens galaxies have a photometric redshift range of zlens ⌠0.3â0.7. The lensing systems range in source imageâlens separation from 2 to 9âarcsec and in enclosed mass from 1012 to 1013âMâ
Kilonova Luminosity Function Constraints Based on Zwicky Transient Facility Searches for 13 Neutron Star Merger Triggers during O3
We present a systematic search for optical counterparts to 13 gravitational wave (GW) triggers involving at least one neutron star during LIGO/Virgo's third observing run (O3). We searched binary neutron star (BNS) and neutron star black hole (NSBH) merger localizations with the Zwicky Transient Facility (ZTF) and undertook follow-up with the Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration. The GW triggers had a median localization area of 4480 degÂČ, a median distance of 267 Mpc, and false-alarm rates ranging from 1.5 to 10â»ÂČâ” yrâ»Âč. The ZTF coverage in the g and r bands had a median enclosed probability of 39%, median depth of 20.8 mag, and median time lag between merger and the start of observations of 1.5 hr. The O3 follow-up by the GROWTH team comprised 340 UltraViolet/Optical/InfraRed (UVOIR) photometric points, 64 OIR spectra, and three radio images using 17 different telescopes. We find no promising kilonovae (radioactivity-powered counterparts), and we show how to convert the upper limits to constrain the underlying kilonova luminosity function. Initially, we assume that all GW triggers are bona fide astrophysical events regardless of false-alarm rate and that kilonovae accompanying BNS and NSBH mergers are drawn from a common population; later, we relax these assumptions. Assuming that all kilonovae are at least as luminous as the discovery magnitude of GW170817 (â16.1 mag), we calculate that our joint probability of detecting zero kilonovae is only 4.2%. If we assume that all kilonovae are brighter than â16.6 mag (the extrapolated peak magnitude of GW170817) and fade at a rate of 1 mag dayâ»Âč (similar to GW170817), the joint probability of zero detections is 7%. If we separate the NSBH and BNS populations based on the online classifications, the joint probability of zero detections, assuming all kilonovae are brighter than â16.6 mag, is 9.7% for NSBH and 7.9% for BNS mergers. Moreover, no more than 10â»âŽ, or Ï > 30° to be consistent with our limits. We look forward to searches in the fourth GW observing run; even 17 neutron star mergers with only 50% coverage to a depth of â16 mag would constrain the maximum fraction of bright kilonovae to <25%
Composition dependent room temperature structure, electric and magnetic properties in magnetoelectric Pb(Fe 1/2 Nb 1/2 )O 3 Pb(Fe 2/3 W 1/3 )O 3 solid-solutions
The Power Board of the KM3NeT Digital Optical Module: design, upgrade, and production
The KM3NeT Collaboration is building an underwater neutrino observatory at
the bottom of the Mediterranean Sea consisting of two neutrino telescopes, both
composed of a three-dimensional array of light detectors, known as digital
optical modules. Each digital optical module contains a set of 31 three inch
photomultiplier tubes distributed over the surface of a 0.44 m diameter
pressure-resistant glass sphere. The module includes also calibration
instruments and electronics for power, readout and data acquisition. The power
board was developed to supply power to all the elements of the digital optical
module. The design of the power board began in 2013, and several prototypes
were produced and tested. After an exhaustive validation process in various
laboratories within the KM3NeT Collaboration, a mass production batch began,
resulting in the construction of over 1200 power boards so far. These boards
were integrated in the digital optical modules that have already been produced
and deployed, 828 until October 2023. In 2017, an upgrade of the power board,
to increase reliability and efficiency, was initiated. After the validation of
a pre-production series, a production batch of 800 upgraded boards is currently
underway. This paper describes the design, architecture, upgrade, validation,
and production of the power board, including the reliability studies and tests
conducted to ensure the safe operation at the bottom of the Mediterranean Sea
throughout the observatory's lifespa
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