1,496 research outputs found
A Catalyst for Urban Renewal: Reservoir Number Three Environmental History Museum
This architectural thesis investigates how architecture can have an impact on urban renewal by strengthening communities with an architecture which promotes human interaction through spatial and programmatic interconnections, as well as promoting relationships between people, their history, and context
Upper mantle anisotropy beneath Australia and Tahiti from P wave polarization: Implications for real-time earthquake location
International audienceWe report measurements of long-period P wave polarization (P pol) in Australia and Tahiti made by combining modeling of the polarization deviation and harmonic analysis. The analysis of the deviation of the horizontal polarization of the P wave as a function of event back azimuth may be used to obtain information about (1) sensor misorientation, (2) dipping discontinuities, (3) seismic anisotropy, and (4) velocity heterogeneities beneath a seismic station. The results from harmonic analysis and a grid search using Snell's law suggest the presence of a dipping seismic discontinuity beneath stations CTAO and CAN in Australia. These results are consistent with published receiver function studies for these stations. The P pol fast axis orientation is close to the NâS absolute plate motion direction at station TAU (Tasmania), which may be due to plate-motion-driven alignment of olivine crystals in the asthenosphere. Interestingly, measurements of SKS splitting at Tahiti (French Polynesia) show an apparent isotropy, whereas an inversion of P pol observations at PPTL seismic station located in Tahiti suggests the presence of two anisotropic layers. The fast axis azimuth is oriented EâW in the upper layer, and it is close to the NWâSE orientation in the lower layer. Since P pol orientations are used for real-time earthquake locations, especially in poorly instrumented areas such as the South Pacific, we show that the bias from anisotropy and sensor misorientation determined here can be corrected to improve the location accuracy, which yields fundamental data for rapid location necessary for effective tsunami warning
Potential Biomarkers for Physical Exercise-Induced Brain Health
Physical exercise has long been recognized as an effective and economic strategy to promote brain health in humans. The cellular and structural changes in the brains of exercised animals, including enhancements of neurogenesis and synaptogenesis, dendritic remodeling, and synaptic plasticity, have been considered as the key biological alterations accounting for exercise-elicited benefits to brain health. However, what transduces body movements into the above-mentioned changes remains largely unknown. Emerging theories indicate that physical activity triggers the release of various factors into the circulation from skeletal muscle (neurotrophins, myokines, and cytokines) and/or adipose tissue (adipokines). In this chapter, we review several of these molecules that are potentially implicated in this process, including neurotrophic factors (BDNF, IGF-1, and VEGF), adipokines (adiponectin and irisin), and myokines/cytokines (IL-15). The relationship, either causal or concomitant, between levels of these molecules (particularly in the blood) and brain function after exercise may help to identify biomarkers that can serve as objective indicators to evaluate exercise therapy on diseased or ageing brain. In addition, unmasking biomarkers may be instrumental in elucidating the mechanisms mediating exercise-induced brain health, thereby contributing to novel drug discovery for treatments to maintain brain health
Reduced fire severity offers near-term buffer to climate-driven declines in conifer resilience across the western United States
Increasing fire severity and warmer, drier postfire conditions are making forests in the western United States (West) vulnerable to ecological transformation. Yet, the relative importance of and interactions between these drivers of forest change remain unresolved, particularly over upcoming decades. Here, we assess how the interactive impacts of changing climate and wildfire activity influenced conifer regeneration after 334 wildfires, using a dataset of postfire conifer regeneration from 10,230 field plots. Our findings highlight declining regeneration capacity across the West over the past four decades for the eight dominant conifer species studied. Postfire regeneration is sensitive to high-severity fire, which limits seed availability, and postfire climate, which influences seedling establishment. In the near-term, projected differences in recruitment probability between low- and high-severity fire scenarios were larger than projected climate change impacts for most species, suggesting that reductions in fire severity, and resultant impacts on seed availability, could partially offset expected climate-driven declines in postfire regeneration. Across 40 to 42% of the study area, we project postfire conifer regeneration to be likely following low-severity but not high-severity fire under future climate scenarios (2031 to 2050). However, increasingly warm, dry climate conditions are projected to eventually outweigh the influence of fire severity and seed availability. The percent of the study area considered unlikely to experience conifer regeneration, regardless of fire severity, increased from 5% in 1981 to 2000 to 26 to 31% by mid-century, highlighting a limited time window over which management actions that reduce fire severity may effectively support postfire conifer regeneration. © 2023 the Author(s)
Mechanisms and in vivo functions of contact inhibition of locomotion
Contact inhibition of locomotion (CIL) is a process whereby a cell ceases motility or
changes its trajectory upon collision with another cell. CIL was initially characterized more than
half a century ago and became a widely studied model system to understand how cells migrate
and dynamically interact. Although CIL fell from interest for several decades, the scientific
community has recently rediscovered this process. We are now beginning to understand the
precise steps of this complex behaviour and to elucidate its regulatory components, including
receptors, polarity proteins and cytoskeletal elements. Furthermore, this process is no longer just
in vitro phenomenology; we now know from several different in vivo models that CIL is essential
for embryogenesis and in governing behaviours such as cell dispersion, boundary formation and
collective cell migration. In addition, changes in CIL responses have been associated with other
physiological processes, such as cancer cell dissemination during metastasis
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
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