3,738 research outputs found
Low-speed Aerodynamic Characteristics of a Large-scale 60 Degree Swept-back Wing with High Lift Devices
Wind-tunnel Investigation of the Low-speed Aerodynamic Characteristics of a Hypersonic Glider Configuration
Deferral To Arbitration After Olin And United Technologies: Has The Nlrb Gone Too Far?
OPTIC: Orbiting Plutonian Topographic Image Craft Proposal for an Unmanned Mission to Pluto
The proposal for an unmanned probe to Pluto is presented and described. The Orbiting Plutonian Topographic Image Craft's (OPTIC's) trip will take twenty years and after its arrival, will begin its data collection which includes image and radar mapping, surface spectral analysis, and magnetospheric studies. This probe's design was developed based on the request for proposal of an unmanned probe to Pluto requirements. The distinct problems which an orbiter causes for each subsystem of the craft are discussed. The final design revolved around two important factors: (1) the ability to collect and return the maximum quantity of information on the Plutonian system; and (2) the weight limitations which the choice of an orbiting craft implied. The velocity requirements of this type of mission severely limited the weight available for mission execution-owing to the large portion of overall weight required as fuel to fly the craft with present technology. The topics covered include: (1) scientific instrumentation; (2) mission management; (3) power and propulsion; (4) attitude and articulation control; (5) structural subsystems; and (6) command, control, and communication
Community Involvement to Address a Long-standing Invasive Species Problem: Aspects of Civic Ecology in Practice
Invasive non-native species (INS) are found in every city around the globe, but their impacts in urban settings as biological agents of visual pollution that block views of natural landscapes and disconnect citizens from nature are not as often addressed as comprehensively as their impacts in natural areas or agricultural settings. The multiple impacts of INS in cities make them ideal candidates for aspects of Civic Ecology Practice, where local environmental stewardship action is taken to enhance green infrastructure and community well-being in urban and other human-dominated systems. We present details of a community driven program focused on removal of an INS, Amur bush honeysuckle (Lonicera maackii), from banks of a creek in Indianapolis, Indiana, in the midwestern USA. Unlike many civic ecology practices, this project was motivated by community response to the long-developing environmental, social, and economic impacts of an INS and includes involvement of a major corporation. In response to local residents’ concerns and following months of planning, over 2,000 volunteers removed more than 760 m3 of Amur bush honeysuckle from 30 acres of land along Fall Creek during a single day. The honeysuckle removal served ecological and environmental goals of removing an invasive species, but it also helped foster in citizens a sense of place and connection with Indianapolis’ waterways, reflecting local history and culture. Aspects of the project can serve as a model for action in other cities
Wind-tunnel Tests of Blowing Boundary-layer Control with Jet Pressure Ratios up to 9.5 on the Trailing-edge Flaps of a 35 Degree Sweptback Wing Airplane
Urocortin 3 marks mature human primary and embryonic stem cell-derived pancreatic alpha and beta cells.
The peptide hormone Urocortin 3 (Ucn 3) is abundantly and exclusively expressed in mouse pancreatic beta cells where it regulates insulin secretion. Here we demonstrate that Ucn 3 first appears at embryonic day (E) 17.5 and, from approximately postnatal day (p) 7 and onwards throughout adult life, becomes a unifying and exclusive feature of mouse beta cells. These observations identify Ucn 3 as a potential beta cell maturation marker. To determine whether Ucn 3 is similarly restricted to beta cells in humans, we conducted comprehensive immunohistochemistry and gene expression experiments on macaque and human pancreas and sorted primary human islet cells. This revealed that Ucn 3 is not restricted to the beta cell lineage in primates, but is also expressed in alpha cells. To substantiate these findings, we analyzed human embryonic stem cell (hESC)-derived pancreatic endoderm that differentiates into mature endocrine cells upon engraftment in mice. Ucn 3 expression in hESC-derived grafts increased robustly upon differentiation into mature endocrine cells and localized to both alpha and beta cells. Collectively, these observations confirm that Ucn 3 is expressed in adult beta cells in both mouse and human and appears late in beta cell differentiation. Expression of Pdx1, Nkx6.1 and PC1/3 in hESC-derived Ucn 3(+) beta cells supports this. However, the expression of Ucn 3 in primary and hESC-derived alpha cells demonstrates that human Ucn 3 is not exclusive to the beta cell lineage but is a general marker for both the alpha and beta cell lineages. Ucn 3(+) hESC-derived alpha cells do not express Nkx6.1, Pdx1 or PC1/3 in agreement with the presence of a separate population of Ucn 3(+) alpha cells. Our study highlights important species differences in Ucn 3 expression, which have implications for its utility as a marker to identify mature beta cells in (re)programming strategies
The Use of Area Suction to Increase the Effectiveness of a Trailing-edge Flap on a Triangular Wing of Aspect Ratio 2
The Use of Area Suction for the Purpose of Improving Trailing-edge Flap Effectiveness on a 35 Degree Sweptback Wing
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