46 research outputs found

    Evaluation of harvest weed seed destruction in U.S. soybean and a survey of waterhemp populations response to dicamba and glufosinate

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    "One impact mill commonly used in commercial production in Australia is known as the Seed Terminator[trademark]. Independent research has shown the Seed Terminator[trademark] to be an effective HWSC tool in Australian grain production systems (Anonymous 2017). There is currently little to no published research on the ability of impact mills to destroy weed seed in United States soybean production systems. Therefore, the objectives of this component of this research are to: 1) quantify header loss of weed seed during soybean harvest, 2) determine the effectiveness of the Seed Terminator[trademark] at destroying weed seed and reducing weed seedbanks following soybean harvest, and 3) determine the effects of the Seed Terminator[trademark] on combine performance."--Justification, page 3.Includes bibliographical references

    Olfactory and vomeronasal system participation in male hamsters' attraction to female vaginal secretions

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    The effects of olfactory (OLF) vomeronasal (VN), or combined deafferentations of male hamsters on their attraction to female hamster vaginal secretions (FHVS) were determined using 2 different attraction tests. In the first, FHVS was placed on one wall of a plastic test chamber, while in the second test, FHVS was rubbed onto 1 of 2 anesthetized castrate hamsters. OLF deafferentation abolished the males' attraction to FHVS in the first test but had no effect in the second. The persistence of FHVS attraction in the anesthetized castrate test depended on the VN system in that its subsequent deafferentation greatly attenuated the attraction. When the VN system was deafferented alone, FHVS attraction was significantly reduced only in males exhibiting severe mating behavior deficits. These results are interpreted to support the hypothesis that the OLF and VN systems may be preferentially responsive to volatile and non-volatile odorants, respectively. Our findings emphasize that both the OLF and VN systems participate in subserving males' attraction to FHVS and their mating with receptive females. Thus each chemosensory system may influence both sexual arousal and copulatory mechanisms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23669/1/0000637.pd

    Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Priscu, J. C., Kalin, J., Winans, J., Campbell, T., Siegfried, M. R., Skidmore, M., Dore, J. E., Leventer, A., Harwood, D. M., Duling, D., Zook, R., Burnett, J., Gibson, D., Krula, E., Mironov, A., McManis, J., Roberts, G., Rosenheim, B. E., Christner, B. C., Kasic, K., Fricker, H. A., Lyons, W. B., Barker, J., Bowling, M., Collins, B., Davis, C., Gagnon, A., Gardner, C., Gustafson, C., Kim, O-S., Li, W., Michaud, A., Patterson, M. O., Tranter, M., Ryan Venturelli, R., Trista Vick-Majors, T., & Elsworth, C. Scientific access into Mercer Subglacial Lake: scientific objectives, drilling operations and initial observations. Annals of Glaciology, 62(85–86), (2021): 340–352, https://doi.org/10.1017/aog.2021.10.The Subglacial Antarctic Lakes Scientific Access (SALSA) Project accessed Mercer Subglacial Lake using environmentally clean hot-water drilling to examine interactions among ice, water, sediment, rock, microbes and carbon reservoirs within the lake water column and underlying sediments. A ~0.4 m diameter borehole was melted through 1087 m of ice and maintained over ~10 days, allowing observation of ice properties and collection of water and sediment with various tools. Over this period, SALSA collected: 60 L of lake water and 10 L of deep borehole water; microbes >0.2 μm in diameter from in situ filtration of ~100 L of lake water; 10 multicores 0.32–0.49 m long; 1.0 and 1.76 m long gravity cores; three conductivity–temperature–depth profiles of borehole and lake water; five discrete depth current meter measurements in the lake and images of ice, the lake water–ice interface and lake sediments. Temperature and conductivity data showed the hydrodynamic character of water mixing between the borehole and lake after entry. Models simulating melting of the ~6 m thick basal accreted ice layer imply that debris fall-out through the ~15 m water column to the lake sediments from borehole melting had little effect on the stratigraphy of surficial sediment cores.This material is based upon work supported by the US National Science Foundation, Section for Antarctic Sciences, Antarctic Integrated System Science program as part of the interdisciplinary (Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated study of carbon cycling in hydrologically-active subglacial environments) project (NSF-OPP 1543537, 1543396, 1543405, 1543453 and 1543441). Ok-Sun Kim was funded by the Korean Polar Research Institute. We are particularly thankful to the SALSA traverse personnel for crucial technical and logistical support. The United States Antarctic Program enabled our fieldwork; the New York Air National Guard and Kenn Borek Air provided air support; UNAVCO provided geodetic instrument support. Hot water drilling activities, including repair and upgrade modifications of the WISSARD hot water drill system, for the SALSA project were supported by a subaward from the Ice Drilling Program of Dartmouth College (NSF-PLR 1327315) to the University of Nebraska-Lincoln. J. Lawrence assisted with manuscript preparation. Finally, we are grateful to C. Dean, the SALSA Project Manager, and R. Ricards, SALSA Project Coordinator at McMurdo Station, for their organizational skills, and B. Huber of Lamont-Doherty Earth Observatory for providing the SBE39 PT sensors and the Nortek Aquadopp current meter and assisting with interpretation of the data. B. Huber also provided helpful input on programing and calibrating the SBE19PlusV2 6112 CTD

    High Connectivity in the Deepwater Snapper Pristipomoides filamentosus (Lutjanidae) across the Indo-Pacific with Isolation of the Hawaiian Archipelago

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    In the tropical Indo-Pacific, most phylogeographic studies have focused on the shallow-water taxa that inhabit reefs to approximately 30 m depth. Little is known about the large predatory fishes, primarily snappers (subfamily Etelinae) and groupers (subfamily Epinephelinae) that occur at 100–400 m. These long-lived, slow-growing species support fisheries across the Indo-Pacific, yet no comprehensive genetic surveys within this group have been conducted. Here we contribute the first range-wide survey of a deepwater Indo-Pacific snapper, Pristipomoides filamentosus, with special focus on Hawai'i. We applied mtDNA cytochrome b and 11 microsatellite loci to 26 samples (N = 1,222) collected across 17,000 km from Hawai'i to the western Indian Ocean. Results indicate that P. filamentosus is a highly dispersive species with low but significant population structure (mtDNA ΦST = 0.029, microsatellite FST = 0.029) due entirely to the isolation of Hawai'i. No population structure was detected across 14,000 km of the Indo-Pacific from Tonga in the Central Pacific to the Seychelles in the western Indian Ocean, a pattern rarely observed in reef species. Despite a long pelagic phase (60–180 days), interisland dispersal as adults, and extensive gene flow across the Indo-Pacific, P. filamentosus is unable to maintain population connectivity with Hawai'i. Coalescent analyses indicate that P. filamentosus may have colonized Hawai'i 26 K–52 K y ago against prevailing currents, with dispersal away from Hawai'i dominating migration estimates. P. filamentosus harbors low genetic diversity in Hawai'i, a common pattern in marine fishes, and our data indicate a single archipelago-wide stock. However, like the Hawaiian Grouper, Hyporthodus quernus, this snapper had several significant pairwise comparisons (FST) clustered around the middle of the archipelago (St. Rogatien, Brooks Banks, Gardner) indicating that this region may be isolated or (more likely) receives input from Johnston Atoll to the south

    Banjo Roots and Branches

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    The story of the banjo\u27s journey from Africa to the western hemisphere blends music, history, and a union of cultures. In Banjo Roots and Branches, Robert B. Winans presents cutting-edge scholarship that covers the instrument\u27s West African origins and its adaptations and circulation in the Caribbean and United States. The contributors provide detailed ethnographic and technical research on gourd lutes and ekonting in Africa and the banza in Haiti while also investigating tuning practices and regional playing styles. Other essays place the instrument within the context of slavery, tell the stories of black banjoists, and shed light on the banjo\u27s introduction into the African- and Anglo-American folk milieus. Wide-ranging and illustrated with twenty color images, Banjo Roots and Branchesoffers a wealth of new information to scholars of African American and folk musics as well as the worldwide community of banjo aficionados.https://cupola.gettysburg.edu/books/1150/thumbnail.jp
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