239 research outputs found
hardRain:An R package for quick, automated rainfall detection in ecoacoustic datasets using a threshold-based approach
The increasing demand for cost-efficient biodiversity data at large spatiotemporal scales has led to an increase in the collection of large ecoacoustic datasets. Whilst the ease of collection and storage of audio data has rapidly increased and costs fallen, methods for robust analysis of the data have not developed so quickly. Identification and classification of audio signals to species level is extremely desirable, but reliability can be highly affected by non-target noise, especially rainfall. Despite this demand, there are few easily applicable pre-processing methods available for rainfall detection for conservation practitioners and ecologists. Here, we use threshold values of two simple measures, Power Spectrum Density (amplitude) and Signal-to-Noise Ratio at two frequency bands, to differentiate between the presence and absence of heavy rainfall. We assess the effect of using different threshold values on Accuracy and Specificity. We apply the method to four datasets from both tropical and temperate regions, and find that it has up to 99% accuracy on tropical datasets (e.g. from the Brazilian Amazon), but performs less well in temperate environments. This is likely due to the intensity of rainfall in tropical forests and its falling on dense, broadleaf vegetation amplifying the sound. We show that by choosing between different threshold values, informed trade-offs can be made between Accuracy and Specificity, thus allowing the exclusion of large amounts of audio data containing rainfall in all locations without the loss of data not containing rain. We assess the impact of using different sample sizes of audio data to set threshold values, and find that 200 15 s audio files represents an optimal trade-off between effort, accuracy and specificity in most scenarios. This methodology and accompanying R package ‘hardRain’ is the first automated rainfall detection tool for pre-processing large acoustic datasets without the need for any additional rain gauge data
Observers in an accelerated universe
If the current acceleration of our Universe is due to a cosmological
constant, then a Coleman-De Luccia bubble will nucleate in our Universe. In
this work, we consider that our observations could be likely in this framework,
consisting in two infinite spaces, if a foliation by constant mean curvature
hypersurfaces is taken to count the events in the spacetime. Thus, we obtain
and study a particular foliation, which covers the existence of most observers
in our part of spacetime.Comment: revised version, accepted in EPJ
Taxonomy, nomenclature and phylogeny of three cladosporium-like hyphomycetes, Sorocybe resinae, Seifertia azaleae and the Hormoconis anamorph of Amorphotheca resinae
Using morphological characters, cultural characters, large subunit and
internal transcribed spacer rDNA (ITS) sequences, and provisions of the
International Code of Botanical Nomenclature, this paper attempts to resolve
the taxonomic and nomenclatural confusion surrounding three species of
cladosporium-like hyphomycetes. The type specimen of Hormodendrum
resinae, the basis for the use of the epithet resinae for the
creosote fungus {either as Hormoconis resinae or Cladosporium
resinae) represents the mononematous synanamorph of the synnematous,
resinicolous fungus Sorocybe resinae. The phylogenetic relationships
of the creosote fungus, which is the anamorph of Amorphotheca
resinae, are with the family Myxotrichaceae, whereas S.
resinae is related to Capronia (Chaetothyriales,
Herpotrichiellaceae). Our data support the segregation of
Pycnostysanus azaleae, the cause of bud blast of rhododendrons, in
the recently described anamorph genus Seifertia, distinct from
Sorocybe; this species is related to the Dothideomycetes but
its exact phylogenetic placement is uncertain. To formally stabilize the name
of the anamorph of the creosote fungus, conservation of Hormodendrum
resinae with a new holotype should be considered. The paraphyly of the
family Myxotrichaceae with the Amorphothecaceae suggested by
ITS sequences should be confirmed with additional genes
Priorities for mitigating greenhouse gas and ammonia emissions to meet UK policy targets
Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely acknowledged that there is a need to further reduce and mitigate emissions across sectors, including agriculture to address the climate emergency and emissions gap. This discussion paper outlines a collation of opinions from a range of experts within agricultural research and advisory roles following a greenhouse gas and ammonia emission mitigation workshop held in the UK in March 2022. The meeting identified the top mitigation priorities within the UK’s agricultural sector to achieve reductions in greenhouse gases and ammonia that are compatible with policy targets. In addition, experts provided an overview of what they believe are the key knowledge gaps, future opportunities and co-benefits to mitigation practices as well as indicating the potential barriers to uptake for mitigation scenarios discussed
HerMES: The contribution to the cosmic infrared background from galaxies selected by mass and redshift
The cosmic infrared background (CIB), discovered in Far
Infrared Absolute Spectrophotometer (FIRAS) data from the
Cosmic Background Explorer (COBE; Puget et al. 1996;
Fixsen et al. 1998), originates from thermal re-radiation of
imagine cutting out hundreds of thumbnails from a map centered
on the positions where galaxies are known to be, and averaging
those thumbnails together until an image of the average galaxy
emerges from the noise. These positional priors can come
in many forms, e.g., they could be catalogs of UV, optical,
IR, or radio sources. Note that the output is the average of
that population in the stacked maps, i.e., there will likely be
sources whose actual fluxes are higher or lower. Thus, the more
homogeneous the sources comprising the input list, the more
meaningful the stacked flux will be.Web of Scienc
Greenhouse gas and ammonia emission mitigation priorities for UK policy targets
Acknowledgements Many thanks to the Association of Applied Biologist’s for organising and hosting the ‘Agricultural greenhouse gases and ammonia mitigation: Solutions, challenges, and opportunities’ workshop. This work was supported with funding from the Scottish Government’s Strategic Research Programme (2022-2027, C2-1 SRUC) and BBSRC (BBS/E/C/000I0320 and BBS/E/C/000I0330). We also acknowledge support from UKRI694 BBSRC (United Kingdom Research and Innovation-Biotechnology and Biological Sciences 695 Research Council; United Kingdom) via grants BBS/E/C/000I0320 and BBS/E/C/000I0330. and Rothamsted Research's Science Initiative Catalyst Award (SICA) supported by BBSRC.Peer reviewedPublisher PD
Large avian frugivores in the Philippines show linear responses to improvements in forest quality
Large avian frugivores are important in ecosystem function, but are seriously threatened across the tropics. To conserve them we must understand their habitat needs and the effects of improved forest management on individual species and the community as a whole. We recorded the presence/absence of 18 parrot, pigeon and hornbill species along nearly 500 km of transects at 24 sites in Luzon, Philippines, and used logistic GLMMs to identify bird-habitat associations based on topographical, forest structure and floristic data taken at 1227 habitat plots. We then searched for more complex relationships and thresholds in species responses along forest quality/restoration gradients using GAMMs. Frugivore species richness was highest in forest with large-girthed trees, although some small-scale agricultural disturbance was tolerated or even favoured. Importantly, richness was highest in forests on flat ground, areas which are usually the first to be converted to agriculture. Individual species were positively associated with large trees but responses to floristic gradients were more variable. Very few species had complex relationships with forest quality; for the great majority, the probability of occurrence increased linearly along the forest quality/restoration gradient. While the precise benefits in terms of seed dispersal, and costs of management, at different points along the quality/restoration gradient are likely to be themselves complex, avian frugivores benefit proportionately from step improvements right along the gradient. Thus, any actions to improve forest quality on Luzon, from reforesting the most degraded lands to preventing degradation of relatively healthy forests, are likely to benefit frugivores
Origins of the Ambient Solar Wind: Implications for Space Weather
The Sun's outer atmosphere is heated to temperatures of millions of degrees,
and solar plasma flows out into interplanetary space at supersonic speeds. This
paper reviews our current understanding of these interrelated problems: coronal
heating and the acceleration of the ambient solar wind. We also discuss where
the community stands in its ability to forecast how variations in the solar
wind (i.e., fast and slow wind streams) impact the Earth. Although the last few
decades have seen significant progress in observations and modeling, we still
do not have a complete understanding of the relevant physical processes, nor do
we have a quantitatively precise census of which coronal structures contribute
to specific types of solar wind. Fast streams are known to be connected to the
central regions of large coronal holes. Slow streams, however, appear to come
from a wide range of sources, including streamers, pseudostreamers, coronal
loops, active regions, and coronal hole boundaries. Complicating our
understanding even more is the fact that processes such as turbulence,
stream-stream interactions, and Coulomb collisions can make it difficult to
unambiguously map a parcel measured at 1 AU back down to its coronal source. We
also review recent progress -- in theoretical modeling, observational data
analysis, and forecasting techniques that sit at the interface between data and
theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue
connected with a 2016 ISSI workshop on "The Scientific Foundations of Space
Weather." 44 pages, 9 figure
Heliolatitude and time variations of solar wind structure from in situ measurements and interplanetary scintillation observations
The 3D structure of solar wind and its evolution in time is needed for
heliospheric modeling and interpretation of energetic neutral atoms
observations. We present a model to retrieve the solar wind structure in
heliolatitude and time using all available and complementary data sources. We
determine the heliolatitude structure of solar wind speed on a yearly time grid
over the past 1.5 solar cycles based on remote-sensing observations of
interplanetary scintillations, in situ out-of-ecliptic measurements from
Ulysses, and in situ in-ecliptic measurements from the OMNI-2 database. Since
the in situ information on the solar wind density structure out of ecliptic is
not available apart from the Ulysses data, we derive correlation formulae
between solar wind speed and density and use the information on the solar wind
speed from interplanetary scintillation observations to retrieve the 3D
structure of solar wind density. With the variations of solar wind density and
speed in time and heliolatitude available we calculate variations in solar wind
flux, dynamic pressure and charge exchange rate in the approximation of
stationary H atoms.Comment: Accepted for publication in Solar Physic
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