5,386 research outputs found
The Value of Urban Parklands: A User Study of the Baldwin Hills Park System
Urban parklands are well-documented as critical resources that provide users with extensive benefits and protect open spaces and natural habitat. The Baldwin Hills (BH) urban park system serves residents of Culver City, Los Angeles, Inglewood, local unincorporated counties, and the Larger Los Angeles County, as well as tourists and visitors from other parts of the region. This poster represents the pilot phase of an impending 2-year comprehensive survey of BH park user experiences that aims to inform improvements to quality of urban recreational spaces. The pilot study focused on 6 heavily used parks/ riverways within the BH system. Ten undergraduate research assistants (URAs) were trained according to LMU’s Institutional Review Board policies for human subjects research. URAs visited each park and conducted user surveys that included the following: frequency of park use, demographics, park activity engagement, park accessibility, and health/ disposition. URAs also conducted strategic counts of the number of park visitors. A total of 8 visitor counts and 236 surveys were conducted. This study yielded numerous recommendations on how to improve local urban parks, such as: extending the park grounds to surrounding neighborhoods, adding public transit stops nearer to the parks, installing educational exhibits around the sites to increase environmental awareness, etc. Future efforts will be focused on expanding the scope and scale of the survey assessments and narrowing down the questions to more user- specific topics.https://digitalcommons.lmu.edu/cures_posters/1000/thumbnail.jp
A Limited Habitable Zone for Complex Life
The habitable zone (HZ) is commonly defined as the range of distances from a
host star within which liquid water, a key requirement for life, may exist on a
planet's surface. Substantially more CO2 than present in Earth's modern
atmosphere is required to maintain clement temperatures for most of the HZ,
with several bars required at the outer edge. However, most complex aerobic
life on Earth is limited by CO2 concentrations of just fractions of a bar. At
the same time, most exoplanets in the traditional HZ reside in proximity to M
dwarfs, which are more numerous than Sun-like G dwarfs but are predicted to
promote greater abundances of gases that can be toxic in the atmospheres of
orbiting planets, such as carbon monoxide (CO). Here we show that the HZ for
complex aerobic life is likely limited relative to that for microbial life. We
use a 1D radiative-convective climate and photochemical models to circumscribe
a Habitable Zone for Complex Life (HZCL) based on known toxicity limits for a
range of organisms as a proof of concept. We find that for CO2 tolerances of
0.01, 0.1, and 1 bar, the HZCL is only 21%, 32%, and 50% as wide as the
conventional HZ for a Sun-like star, and that CO concentrations may limit some
complex life throughout the entire HZ of the coolest M dwarfs. These results
cast new light on the likely distribution of complex life in the universe and
have important ramifications for the search for exoplanet biosignatures and
technosignatures.Comment: Revised including additional discussion. Published Gold OA in ApJ. 9
pages, 5 figures, 5 table
Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides
The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures
Scalable Fluidic Injector Arrays for Viral Targeting of Intact 3-D Brain Circuits
Our understanding of neural circuits--how they mediate the computations that subserve sensation, thought, emotion, and action, and how they are corrupted in neurological and psychiatric disorders--would be greatly facilitated by a technology for rapidly targeting genes to complex 3-dimensional neural circuits, enabling fast creation of "circuit-level transgenics." We have recently developed methods in which viruses encoding for light-sensitive proteins can sensitize specific cell types to millisecond-timescale activation and silencing in the intact brain. We here present the design and implementation of an injector array capable of delivering viruses (or other fluids) to dozens of defined points within the 3-dimensional structure of the brain (Figure. 1A, 1B). The injector array comprises one or more displacement pumps that each drive a set of syringes, each of which feeds into a polyimide/fused-silica capillary via a high-pressure-tolerant connector. The capillaries are sized, and then inserted into, desired locations specified by custom-milling a stereotactic positioning board, thus allowing viruses or other reagents to be delivered to the desired set of brain regions. To use the device, the surgeon first fills the fluidic subsystem entirely with oil, backfills the capillaries with the virus, inserts the device into the brain, and infuses reagents slowly (<0.1 microliters/min). The parallel nature of the injector array facilitates rapid, accurate, and robust labeling of entire neural circuits with viral payloads such as optical sensitizers to enable light-activation and silencing of defined brain circuits. Along with other technologies, such as optical fiber arrays for light delivery to desired sets of brain regions, we hope to create a toolbox that enables the systematic probing of causal neural functions in the intact brain. This technology may not only open up such systematic approaches to circuit-focused neuroscience in mammals, and facilitate labeling of brain regions in large animals such as non-human primates, but may also open up a clinical translational path for cell-specific optical control prosthetics, whose precision may enable improved treatment of intractable brain disorders. Finally, such devices as described here may facilitate precisely-timed fluidic delivery of other payloads, such as stem cells and pharmacological agents, to 3-dimensional structures, in an easily user-customizable fashion.National Institutes of Health (U.S.) (NIH Director's New Innovator Award (DP2 OD002002-01)National Institutes of Health (U.S.) (NIH Challenge Grant 1RC1MH088182-01)National Institutes of Health (U.S.) (NIH Grand Opportunities Grant 1RC2DE020919-01)National Institutes of Health (U.S.) (NIH Grand Opportunities Grant NIH 1R01NS067199-01)National Science Foundation (U.S.) (NSF 0848804)National Science Foundation (U.S.) (NSF 0835878)McGovern Institute for Brain Research at MIT (Neurotechnology Award Program)National Alliance for Research on Schizophrenia and Depression (U.S.)Alfred P. Sloan FoundationDr. Gerald Burnett and Marjorie BurnettUnited States. Dept. of DefenseSociety for Neuroscience (SFN Research Award for Innovation in Neuroscience)Massachusetts Institute of Technology. Media LaboratoryBenesse FoundationWallace H. Coulter Foundatio
The Importance of UV Capabilities for Identifying Inhabited Exoplanets with Next Generation Space Telescopes
The strongest remotely detectable signature of life on our planet today is
the photosynthetically produced oxygen (O2) in our atmosphere. However, recent
studies of Earth's geochemical proxy record suggest that for all but the last
~500 million years, atmospheric O2 would have been undetectable to a remote
observer--and thus a potential false negative for life. During an extended
period in Earth's middle history (2.0 - 0.7 billion years ago, Ga), O2 was
likely present but in low concentrations, with pO2 estimates of ~0.1 - 1% of
present day levels. Although O2 has a weak spectral impact at these low
abundances, O3 in photochemical equilibrium with that O2 would produce notable
spectral features in the UV Hartley-Huggins band (~0.25 um), with a weaker
impact in the mid-IR band near 9.7 um. Thus, taking Earth history as an
informative example, there likely exists a category of exoplanets for which
conventional biosignatures can only be identified in the UV. In this paper, we
emphasize the importance of UV capabilities in the design of future space-based
direct imaging telescopes such as HabEx or LUVOIR to detect O3 on planets with
intermediate oxygenation states. We also discuss strategies for mitigating
against 'false positives'--that is, O3 produced by abiotic processes. More
generally, this specific example highlights the broad implications of studying
Earth history as a window into understanding potential exoplanet biosignatures
Assessing Potential Change in Louisiana Juvenile Detainee’s Knowledge and Attitude during Garden Programming
University-based horticulture departments have explored the relationship between garden programs and increased horticulture knowledge among primary and secondary students. Studies have established positive correlations between youth garden programs and increased garden knowledge. The objective of this research was to determine if participation in a garden workshop series had positive effects on youth detained in juvenile detention centers garden-based knowledge and immediate mood. Participation led to a 17% increase in garden-based knowledge (P ? 0.05) and a positive shift in mood (P ? 0.05) on two of the three days of the workshop series. Based on this experience, we highly recommend juvenile detention centers incorporate garden programming as additional educational opportunities for detained youth
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