91 research outputs found
Has the evolution of complexity in the amphibian papilla influenced anuran speciation rates?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72375/1/j.1420-9101.2006.01079.x.pd
The DECam Ecliptic Exploration Project (DEEP) IV: Constraints on the shape distribution of bright TNOs
We present the methods and results from the discovery and photometric
measurement of 26 bright (VR 24 trans-Neptunian objects (TNOs) during the
first year (2019-20) of the DECam Ecliptic Exploration Project (DEEP). The DEEP
survey is an observational TNO survey with wide sky coverage, high sensitivity,
and a fast photometric cadence. We apply a computer vision technique known as a
progressive probabilistic Hough transform to identify linearly-moving transient
sources within DEEP photometric catalogs. After subsequent visual vetting, we
provide a photometric and astrometric catalog of our TNOs. By modeling the
partial lightcurve amplitude distribution of the DEEP TNOs using Monte Carlo
techniques, we find our data to be most consistent with an average TNO axis
ratio b/a 0.5, implying a population dominated by non-spherical objects.
Based on ellipsoidal gravitational stability arguments, we find our data to be
consistent with a TNO population containing a high fraction of contact binaries
or other extremely non-spherical objects. We also discuss our data as evidence
that the expected binarity fraction of TNOs may be size-dependent
Altered Neural and Behavioral Dynamics in Huntington's Disease: An Entropy Conservation Approach
Background: Huntington’s disease (HD) is an inherited condition that results in neurodegeneration of the striatum, the forebrain structure that processes cortical information for behavioral output. In the R6/2 transgenic mouse model of HD, striatal neurons exhibit aberrant firing patterns that are coupled with reduced flexibility in the motor system. The aim of this study was to test the patterns of unpredictability in brain and behavior in wild-type (WT) and R6/2 mice. Methodology/Principal Findings: Striatal local field potentials (LFP) were recorded from 18 WT and 17 R6/2 mice (aged 8– 11 weeks) while the mice were exploring a plus-shaped maze. We targeted LFP activity for up to 2 s before and 2 s after each choice-point entry. Approximate Entropy (ApEn) was calculated for LFPs and Shannon Entropy was used to measure the probability of arm choice, as well as the likelihood of making consecutive 90-degree turns in the maze. We found that although the total number of choice-point crossings and entropy of arm-choice probability was similar in both groups, R6/2 mice had more predictable behavioral responses (i.e., were less likely to make 90-degree turns and perform them in alternation with running straight down the same arm), while exhibiting more unpredictable striatal activity, as indicated by higher ApEn values. In both WT and R6/2 mice, however, behavioral unpredictability was negatively correlated with LFP ApEn. Conclusions/Significance: HD results in a perseverative exploration of the environment, occurring in concert with mor
The DECam Ecliptic Exploration Project (DEEP) II. Observational Strategy and Design
We present the DECam Ecliptic Exploration Project (DEEP) survey strategy
including observing cadence for orbit determination, exposure times, field
pointings and filter choices. The overall goal of the survey is to discover and
characterize the orbits of a few thousand Trans-Neptunian Objects (TNOs) using
the Dark Energy Camera (DECam) on the Cerro Tololo Inter-American Observatory
(CTIO) Blanco 4 meter telescope. The experiment is designed to collect a very
deep series of exposures totaling a few hours on sky for each of several 2.7
square degree DECam fields-of-view to achieve a magnitude of about 26.2 using a
wide VR filter which encompasses both the V and R bandpasses. In the first
year, several nights were combined to achieve a sky area of about 34 square
degrees. In subsequent years, the fields have been re-visited to allow TNOs to
be tracked for orbit determination. When complete, DEEP will be the largest
survey of the outer solar system ever undertaken in terms of newly discovered
object numbers, and the most prolific at producing multi-year orbital
information for the population of minor planets beyond Neptune at 30 au.Comment: 29 pages, 4 figures and 4 table
Mechanics of the exceptional anuran ear
The anuran ear is frequently used for studying fundamental properties of vertebrate auditory systems. This is due to its unique anatomical features, most prominently the lack of a basilar membrane and the presence of two dedicated acoustic end organs, the basilar papilla and the amphibian papilla. Our current anatomical and functional knowledge implies that three distinct regions can be identified within these two organs. The basilar papilla functions as a single auditory filter. The low-frequency portion of the amphibian papilla is an electrically tuned, tonotopically organized auditory end organ. The high-frequency portion of the amphibian papilla is mechanically tuned and tonotopically organized, and it emits spontaneous otoacoustic emissions. This high-frequency portion of the amphibian papilla shows a remarkable, functional resemblance to the mammalian cochlea
Deep Drilling in the Time Domain with DECam: Survey Characterization
This paper presents a new optical imaging survey of four deep drilling fields
(DDFs), two Galactic and two extragalactic, with the Dark Energy Camera (DECam)
on the 4 meter Blanco telescope at the Cerro Tololo Inter-American Observatory
(CTIO). During the first year of observations in 2021, 4000 images covering
21 square degrees (7 DECam pointings), with 40 epochs (nights) per field
and 5 to 6 images per night per filter in , , , and/or , have
become publicly available (the proprietary period for this program is waived).
We describe the real-time difference-image pipeline and how alerts are
distributed to brokers via the same distribution system as the Zwicky Transient
Facility (ZTF). In this paper, we focus on the two extragalactic deep fields
(COSMOS and ELAIS-S1), characterizing the detected sources and demonstrating
that the survey design is effective for probing the discovery space of faint
and fast variable and transient sources. We describe and make publicly
available 4413 calibrated light curves based on difference-image detection
photometry of transients and variables in the extragalactic fields. We also
present preliminary scientific analysis regarding Solar System small bodies,
stellar flares and variables, Galactic anomaly detection, fast-rising
transients and variables, supernovae, and active galactic nuclei.Comment: 22 pages, 17 figures, 2 tables. Accepted to MNRA
Bioreactors as engineering support to treat cardiac muscle and vascular disease
Cardiovascular disease is the leading cause of morbidity and mortality in the Western World. The inability of fully differentiated, load-bearing cardiovascular tissues to in vivo regenerate and the limitations of the current treatment therapies greatly motivate the efforts of cardiovascular tissue engineering to become an effective clinical strategy for injured heart and vessels. For the effective production of organized and functional cardiovascular engineered constructs in vitro, a suitable dynamic environment is essential, and can be achieved and maintained within bioreactors. Bioreactors are technological devices that, while monitoring and controlling the culture environment and stimulating the construct, attempt to mimic the physiological milieu. In this study, a review of the current state of the art of bioreactor solutions for cardiovascular tissue engineering is presented, with emphasis on bioreactors and biophysical stimuli adopted for investigating the mechanisms influencing cardiovascular tissue development, and for eventually generating suitable cardiovascular tissue replacements
From Data to Software to Science with the Rubin Observatory LSST
The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) dataset
will dramatically alter our understanding of the Universe, from the origins of
the Solar System to the nature of dark matter and dark energy. Much of this
research will depend on the existence of robust, tested, and scalable
algorithms, software, and services. Identifying and developing such tools ahead
of time has the potential to significantly accelerate the delivery of early
science from LSST. Developing these collaboratively, and making them broadly
available, can enable more inclusive and equitable collaboration on LSST
science.
To facilitate such opportunities, a community workshop entitled "From Data to
Software to Science with the Rubin Observatory LSST" was organized by the LSST
Interdisciplinary Network for Collaboration and Computing (LINCC) and partners,
and held at the Flatiron Institute in New York, March 28-30th 2022. The
workshop included over 50 in-person attendees invited from over 300
applications. It identified seven key software areas of need: (i) scalable
cross-matching and distributed joining of catalogs, (ii) robust photometric
redshift determination, (iii) software for determination of selection
functions, (iv) frameworks for scalable time-series analyses, (v) services for
image access and reprocessing at scale, (vi) object image access (cutouts) and
analysis at scale, and (vii) scalable job execution systems.
This white paper summarizes the discussions of this workshop. It considers
the motivating science use cases, identified cross-cutting algorithms,
software, and services, their high-level technical specifications, and the
principles of inclusive collaborations needed to develop them. We provide it as
a useful roadmap of needs, as well as to spur action and collaboration between
groups and individuals looking to develop reusable software for early LSST
science.Comment: White paper from "From Data to Software to Science with the Rubin
Observatory LSST" worksho
From Data to Software to Science with the Rubin Observatory LSST
editorial reviewedThe Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) dataset will dramatically alter our understanding of the Universe, from the origins of the Solar System to the nature of dark matter and dark energy. Much of this research will depend on the existence of robust, tested, and scalable algorithms, software, and services. Identifying and developing such tools ahead of time has the potential to significantly accelerate the delivery of early science from LSST. Developing these collaboratively, and making them broadly available, can enable more inclusive and equitable collaboration on LSST science. To facilitate such opportunities, a community workshop entitled "From Data to Software to Science with the Rubin Observatory LSST" was organized by the LSST Interdisciplinary Network for Collaboration and Computing (LINCC) and partners, and held at the Flatiron Institute in New York, March 28-30th 2022. The workshop included over 50 in-person attendees invited from over 300 applications. It identified seven key software areas of need: (i) scalable cross-matching and distributed joining of catalogs, (ii) robust photometric redshift determination, (iii) software for determination of selection functions, (iv) frameworks for scalable time-series analyses, (v) services for image access and reprocessing at scale, (vi) object image access (cutouts) and analysis at scale, and (vii) scalable job execution systems. This white paper summarizes the discussions of this workshop. It considers the motivating science use cases, identified cross-cutting algorithms, software, and services, their high-level technical specifications, and the principles of inclusive collaborations needed to develop them. We provide it as a useful roadmap of needs, as well as to spur action and collaboration between groups and individuals looking to develop reusable software for early LSST science
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