164 research outputs found
Snowshoe Hare and Forest Structure Relationships in Western Wyoming
Snowshoe hares (Lepus americanus) are a critically important prey species for Canada lynx (Lynx canadensis). Determination of snowshoe hare distribution and abundance is needed in western Wyoming for lynx conservation. We used linear regression to examine the correlations between snowshoe hare density, as determined by mark-recapture estimates, and fecal pellet plot counts on both uncleared and annually cleared plots on the Bridger-Teton National Forest, western Wyoming. We found significant correlations between hare density estimates and fecal pellet counts for both uncleared and annually cleared pellet counts; however the relationship was much stronger for annually cleared pellet counts. Adjusting the buffer size by omitting hard habitat edges (not used by hares) around the trapping grids improved correlations between hare density and fecal pellet counts further. We recommend pellet counts from annually cleared plots be used when precise estimates of snowshoe hare abundance are required. Though precision is sacrificed when using uncleared plots, they are useful as a coarse index of habitat use by hares. The derived regression equations should be used to identify foraging habitat for lynx in western Wyoming. In addition to snowshoe hares, in western Wyoming red squirrels (Tamiasciurus hudsonicus) and grouse (Bonasa umbellus and Dendragapus obscurus) are used by Canada lynx. Whether young forests or older multi-storied forests contain more snowshoe hares, red squirrels, and grouse in western Wyoming is currently unknown. We estimated snowshoe hare density, and indexed red squirrel and forest grouse abundance in 3 classes of 30-70-year-old lodgepole pine (Pinus contorta) and 4 classes of mature multi-storied forest with a spruce (Picea engelmannii)-fir (Abies lasiocarpa) component. We recorded landscape and forest structure characteristics to understand how these influence lynx prey abundance. Overall, snowshoe hares, red squirrels, and forest grouse were more abundant in multi-storied forests than young forests. Forest attributes that predicted prey abundance were often more prevalent in multi-storied forests. Results from this study suggest that multi-storied forests with a spruce-fir component were disproportionately important to snowshoe hares, red squirrels, and forest grouse in western Wyoming. Canada lynx conservation efforts should focus on maintaining, enhancing, and promoting multi-storied forests in this region
Painful losses
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/1/jhm2610-sup-0001-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/2/jhm2610.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/3/jhm2610-sup-0002-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/4/jhm2610-sup-0005-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/5/jhm2610-sup-0003-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/6/jhm2610-sup-0004-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/7/jhm2610_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/8/jhm2610-sup-0007-suppinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134073/9/jhm2610-sup-0006-suppinfo.pd
The ChatGPT Artificial Intelligence Chatbot: How Well Does It Answer Accounting Assessment Questions?
ChatGPT, a language-learning model chatbot, has garnered considerable attention for its ability to respond to usersâ questions. Using data from 14 countries and 186 institutions, we compare ChatGPT and student performance for 28,085 questions from accounting assessments and textbook test banks. As of January 2023, ChatGPT provides correct answers for 56.5 percent of questions and partially correct answers for an additional 9.4 percent of questions. When considering point values for questions, students significantly outperform ChatGPT with a 76.7 percent average on assessments compared to 47.5 percent for ChatGPT if no partial credit is awarded and 56.5 percent if partial credit is awarded. Still, ChatGPT performs better than the student average for 15.8 percent of assessments when we include partial credit. We provide evidence of how ChatGPT performs on different question types, accounting topics, class levels, open/closed assessments, and test bank questions. We also discuss implications for accounting education and research
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds
The Numeniini is a tribe of thirteen wader species (Scolopacidae, Charadriiformes) of which seven are near-threatened or globally threatened, including two critically endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migratory flyways. Most threats are increasing in intensity, particularly in non-breeding areas, where habitat loss resulting from residential and commercial development, aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic native species and climate change) were identified as widely affecting breeding areas. Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation; related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Three priority actions were associated with monitoring and research: to monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites), to deploy tracking technologies to identify migratory connectivity, and to monitor land-cover change across breeding and non-breeding areas. Two priority actions were focused on conservation and policy responses: to identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian - Australasian Flyway), and to implement successful conservation interventions at a sufficient scale across human-dominated landscapes for speciesâ recovery to be achieved. If implemented urgently, these measures in combination have the potential to alter the current population declines of many Numeniini species and provide a template for the conservation of other groups of threatened species
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
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