3,968 research outputs found

    Archaeological Survey Investigations of Private Land within the boundaries of the proposed Lower Bois d’Arc Creek Reservoir Project, Fannin County, Texas

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    At the request of a private landowner that has property within the boundaries of the proposed Lower Bois d’Arc Creek Reservoir in Fannin County, we completed volunteer archaeological survey investigations on a portion of this tract of private land on July 18, 2015. The proposed Lower Bois d’Arc Creek Reservoir is to be more than 16,500 acres in size; the project sponsor is the North Texas Municipal Water District, and the Tulsa District of the U.S. Army Corps of Engineers is currently reviewing the project sponsor’s application for a Department of the Army permit under Section 404 of the Clean Water Act to construct the reservoir and associated facilities. Although the project area associated with the proposed reservoir is more than 17,000 acres, only 5,000 acres of the proposed project have received an archaeological survey. Based on consultation between the project sponsor, the Texas Historical Commission, and the Tulsa District, the remainder of the project area will apparently not receive archaeological survey investigations. The private lands we have investigated along Bois d’Arc Creek in the proposed reservoir area have not been examined previously by a professional archaeological survey team; these lands will be inundated by the flood pool of the reservoir as currently proposed. The landowner had contacted the Tulsa District in 2008 to inform them that there were archaeological sites on the property, but the Tulsa District has yet to follow up on that information

    Sprinklers, Crop Water Use, and Irrigation Time: Beaver County

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    Age-Friendly Cities and Older Indigenous People: An Exploratory Study in Prince George, Canada

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    Cities around the world are responding to aging populations and equity concerns for older people by developing age-friendly communities plans, following the World Health Organization’s guidelines. Such plans, however, often fail to account for the wide diversity of older people in cities, with the result that some older people, including Indigenous older people, do not see their needs reflected in age-friendly planning and policies. This article reports on a study involving 10 older First Nations and Métis women in the city of Prince George, Canada, comparing the expressed needs of these women with two age-friendly action plans: that of the city of Prince George, and that of the Northern Health Authority. Four main categories were raised in a group discussion and interview with these women at the Prince George Native Friendship Centre: availability of health care services, accessibility and affordability of programs and services, special roles of Indigenous Elders, and experiences of racism and discrimination. There are many areas of synergy between the needs expressed by the women and the two action plans; however, certain key areas are missing from the action plans; in particular, specific strategies for attending to the needs of Indigenous and other older populations who often feel marginalized in health care and in age-friendly planning

    Omnidirectional Sensory and Motor Volumes in Electric Fish

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    Active sensing organisms, such as bats, dolphins, and weakly electric fish, generate a 3-D space for active sensation by emitting self-generated energy into the environment. For a weakly electric fish, we demonstrate that the electrosensory space for prey detection has an unusual, omnidirectional shape. We compare this sensory volume with the animal's motor volume—the volume swept out by the body over selected time intervals and over the time it takes to come to a stop from typical hunting velocities. We find that the motor volume has a similar omnidirectional shape, which can be attributed to the fish's backward-swimming capabilities and body dynamics. We assessed the electrosensory space for prey detection by analyzing simulated changes in spiking activity of primary electrosensory afferents during empirically measured and synthetic prey capture trials. The animal's motor volume was reconstructed from video recordings of body motion during prey capture behavior. Our results suggest that in weakly electric fish, there is a close connection between the shape of the sensory and motor volumes. We consider three general spatial relationships between 3-D sensory and motor volumes in active and passive-sensing animals, and we examine hypotheses about these relationships in the context of the volumes we quantify for weakly electric fish. We propose that the ratio of the sensory volume to the motor volume provides insight into behavioral control strategies across all animals

    An Economic Analysis of Carbon Sequestration for Wheat and Grain Sorghum Production in Kansas

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    This study examined the economic potential with and without carbon credit payments of two crop and tillage systems in South Central Kansas that could reduce carbon dioxide emissions and sequester carbon in the soil. Experiment station cropping practices, yield data, and soil carbon data for continuously cropped wheat and grain sorghum produced with conventional tillage and no-tillage from1986 to 1995 were used to determine soil carbon changes and to develop enterprise budgets to determine expected net returns for a typical dryland farm in South Central Kansas. No-till had lower net returns because of lower yields and higher overall costs. Both crops produced under no-till had higher annual soil C gains than under conventional tillage. Carbon credit payments may be critical to induce farm managers to use cropping practices, such as no-till, that sequester soil carbon. The carbon credit payments needed will be highly dependent on cropping system production costs, especially herbicide costs, which substitute for tillage as a means of weed control. The C values estimated in this study that would provide an incentive to adopt no-tillage range from 0to0 to 95.991ton/year, depending upon the assumption about herbicide costs. In addition, if producers were compensated for other environmental benefits associated with no-till, carbon credits could be reduced.carbon credit value, carbon sequestration, grain sorghum, no-tillage, wheat, Crop Production/Industries,

    DERIVED CARBON CREDIT VALUES FOR CARBON SEQUESTRATION: DO CO2 EMISSIONS FROM PRODUCTION INPUTS MATTER ?

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    An economic analysis was conducted involving wheat and grain sorghum production systems that affect carbon dioxide emissions and sequester soil carbon. Parameters examined were expected net returns, changes in net carbon sequestered and the value of carbon credits necessary to equate net returns from systems that sequester more carbon to those that sequester less with and without adjustments for CO2 emissions from production inputs. Evaluations were based on experiment station cropping practices, yield, and soil carbon data for continuously cropped and rotated wheat and grain sorghum produced with conventional and no-tillage. No-till had lower net returns because of lower yields and higher overall costs. Both crops produced under no-till had higher annual soil C gains than under conventional tillage. However, no-till systems had higher total atmospheric emissions of C from production inputs. The differences were relatively small. The C values estimated in this study that would equate net returns of no-tillage to conventional tillage range from 7.82to7.82 to 58.69/ton/yr when C emissions from production inputs were subtracted from soil carbon sequestered and 7.79to7.79 to 54.99/ton/yr when atmospheric emissions were not considered.Environmental Economics and Policy,

    Bose-Einstein Condensation of Long-Lifetime Polaritons in Thermal Equilibrium

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    Exciton-polaritons in semiconductor microcavities have been used to demonstrate quantum effects such as Bose-Einstein condensation, superfluity, and quantized vortices. However, in these experiments, the polaritons have not reached thermal equilibrium when they undergo the transition to a coherent state. This has prevented the verification of one of the canonical predictions for condensation, namely the phase diagram. In this work, we have created a polariton gas in a semiconductor microcavity in which the quasiparticles have a lifetime much longer than their thermalization time. This allows them to reach thermal equilibrium in a laser-generated confining trap. Their energy distributions are well fit by equilibrium Bose-Einstein distributions over a broad range of densities and temperatures from very low densities all the way up to the threshold for Bose-Einstein condensation. The good fits of the Bose-Einstein distribution over a broad range of density and temperature imply that the particles obey the predicted power law for the phase boundary of Bose-Einstein condensation
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