1,226 research outputs found

    Seedbed Effects on Grass Establishment on Abandoned Nebraska Sandhills Cropland

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    Perennial grass establishment on abandoned cropland in the Nebraska Sandhills difficult due to low soil fertility, organic matter, and water holding capacity and high potential erodibility. Establishment is further complicated by unpredictable precipitation and weed competition. Two warm-season grasses: sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.] and switchgrass (Panicam virgatum L.); and 2 cool-season grasses: smooth brome (Bromus inermis Leyss.) and intermediate wheat-grass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. were evaluated with spring-seeded field trials. Seedbed preparation [untilled, disced, and dead oat (Avena sativa L.) cover (DOC)] effect on seeded grass and nonseeded species densities was evaluated in 1985 and 1986 at 2 locations on Valentine sands (Aquic Ustipsamment). In 1985 1 site was irrigated. Both sites were dryland in 1986. Stand failure (\u3c 5 seedlings/m2) occurred on the dryland rite in 1985 due to low, erratic precipitation. Stands evaluated in June 1986 on plots established with irrigation in 1985 had 38, 46, and 61 plants/m2 for the untilled, disced, and DOC seedbeds, respectively. The disced or DOC seedbeds were required for successful (\u3e plants/m2) dryland seedings in 1986 at both locations. Irrigation the establishment year minimized risk of stand failure and allowed the use of my seedbed preparation or grass species studied. Sand bluestem was the only species to establish both years. However, if a dryland seedling of a cool-season species is desired, intermediate wheatgrass appeared more adapted than smooth brome

    Reconstructing Middle and Upper Paleolithic human mobility in Portuguese Estremadura through laser ablation strontium isotope analysis

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    Understanding mobility and landscape use is important in reconstructing subsistence behavior, range, and group size, and it may contribute to our understanding of phenomena such as the dynamics of biological and cultural interactions between distinct populations of Upper Pleistocene humans. However, studies using traditional strontium isotope analysis are generally limited to identifying locations of childhood residence or nonlocal individuals and lack the sampling resolution to detect movement over short timescales. Here, using an optimized methodology, we present highly spatially resolved 87Sr/86Sr measurements made by laser ablation multicollector inductively coupled plasma mass spectrometry along the growth axis of the enamel of two marine isotope stage 5b, Middle Paleolithic Neanderthal teeth (Gruta da Oliveira), a Tardiglacial, Late Magdalenian human tooth (Galeria da Cisterna), and associated contemporaneous fauna from the Almonda karst system, Torres Novas, Portugal. Strontium isotope mapping of the region shows extreme variation in 87Sr/86Sr, with values ranging from 0.7080 to 0.7160 over a distance of c. 50 km, allowing short-distance (and arguably short-duration) movement to be detected. We find that the early Middle Paleolithic individuals roamed across a subsistence territory of approximately 600 km2 , while the Late Magdalenian individual parsimoniously fits a pattern of limited, probably seasonal movement along the right bank of the 20-km-long Almonda River valley, between mouth and spring, exploiting a smaller territory of approximately 300 km2 . We argue that the differences in territory size are due to an increase in population density during the Late Upper Paleolithic

    Successful Approaches for the Use of Unmanned Aerial Systems by Surface Transportation Agencies

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    The past decade has seen ever-increasing attention and resources dedicated to the application and operation of unmanned aircraft systems (UASs). Beginning with issuance of special airworthiness certificates in the experimental category for unmanned aircraft in 2007, up to the Federal Aviation Administration’s (FAA’s) Modernization and Reform Act of 2012 and creation of Title 14 Code of Federal Regulations (CFR) §107 and §101, the complexity and breadth of applications for UAS technology have flourished. Recognizing the interest and potential benefits to the surface transportation community the National Cooperative Highway Research Program (NCHRP) commissioned Scan 17-01 to accelerate beneficial innovation by facilitating information sharing and technology exchange among the states and other transportation agencies. Results from a desk scan, amplifying questions, and a peer exchange workshop produced conclusions and recommendations in seven topic areas for transportation agencies to consider when getting started using a UAS

    The Maine Annex, vol. 1, no. 6

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    The Maine Annex, published by the students of the University of Maine at the Brunswick Campus, was launched January 10, 1947. Editors introduced the publication as the product of a group of progressive students attending the Brunswick Campus. The goal of the publication, according to editors, was to tell the story of our life on this campus. The four-page, tabloid-sized paper included display advertising from area businesses. Among front-page news are the results of the election of Class Officers and planning for a student Minstrel Show and dance to include black-face performances by University of Maine, Brunswick campus students

    The Maine Annex, vol. 1, no. 5

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    The Maine Annex, published by the students of the University of Maine at the Brunswick Campus, was launched January 10, 1947. Editors introduced the publication as the product of a group of progressive students attending the Brunswick Campus. The goal of the publication, according to editors, was to tell the story of our life on this campus. The four-page, tabloid-sized paper included display advertising from area businesses. Among front-page news is coverage of the pending election of class officers

    The Maine Annex, vol. 1, no. 4

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    The Maine Annex, published by the students of the University of Maine at the Brunswick Campus, was launched January 10, 1947. Editors introduced the publication as the product of a group of progressive students attending the Brunswick Campus. The goal of the publication, according to editors, was to tell the story of our life on this campus. The four-page, tabloid-sized paper included display advertising from area businesses. Among front-page news was a stage performance by American poet, educator, writer, and Brunswick, Maine native son, Robert Peter Tristram Coffin

    The Maine Annex, vol. 1, no. 1

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    The Maine Annex, published by the students of the University of Maine at the Brunswick Campus, was launched January 10, 1947. Editors introduced the publication as the product of a group of progressive students attending the Brunswick Campus. The goal of the publication, according to editors, was to tell the story of our life on this campus. The four-page, tabloid-sized paper included display advertising from area businesses. Following World War II, the federal G.I. Bill enabled approximately 2.3 million, predominantly white male Veterans to receive a post-secondary education. To accommodate increased enrollment, in 1946 the University of Maine established the Brunswick Campus at the former Brunswick Naval Air Station. The remote campus operated until spring 1949, when Veteran registrations waned. Among stories covered in the first issue of The Maine Annex includes The Fate of Your College Dollar, by Bill Nisbet, which discusses how student tuition and fees were distributed

    Science and Ideology in Economic, Political, and Social Thought

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    This paper has two sources: One is my own research in three broad areas: business cycles, economic measurement and social choice. In all of these fields I attempted to apply the basic precepts of the scientific method as it is understood in the natural sciences. I found that my effort at using natural science methods in economics was met with little understanding and often considerable hostility. I found economics to be driven less by common sense and empirical evidence, then by various ideologies that exhibited either a political or a methodological bias, or both. This brings me to the second source: Several books have appeared recently that describe in historical terms the ideological forces that have shaped either the direct areas in which I worked, or a broader background. These books taught me that the ideological forces in the social sciences are even stronger than I imagined on the basis of my own experiences. The scientific method is the antipode to ideology. I feel that the scientific work that I have done on specific, long standing and fundamental problems in economics and political science have given me additional insights into the destructive role of ideology beyond the history of thought orientation of the works I will be discussing

    Eosinophils Are Important for Protection, Immunoregulation and Pathology during Infection with Nematode Microfilariae

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    Eosinophil responses typify both allergic and parasitic helminth disease. In helminthic disease, the role of eosinophils can be both protective in immune responses and destructive in pathological responses. To investigate whether eosinophils are involved in both protection and pathology during filarial nematode infection, we explored the role of eosinophils and their granule proteins, eosinophil peroxidase (EPO) and major basic protein-1 (MBP-1), during infection with Brugia malayi microfilariae. Using eosinophil-deficient mice (PHIL), we further clarify the role of eosinophils in clearance of microfilariae during primary, but not challenge infection in vivo. Deletion of EPO or MBP-1 alone was insufficient to abrogate parasite clearance suggesting that either these molecules are redundant or eosinophils act indirectly in parasite clearance via augmentation of other protective responses. Absence of eosinophils increased mast cell recruitment, but not other cell types, into the broncho-alveolar lavage fluid during challenge infection. In addition absence of eosinophils or EPO alone, augmented parasite-induced IgE responses, as measured by ELISA, demonstrating that eosinophils are involved in regulation of IgE. Whole body plethysmography indicated that nematode-induced changes in airway physiology were reduced in challenge infection in the absence of eosinophils and also during primary infection in the absence of EPO alone. However lack of eosinophils or MBP-1 actually increased goblet cell mucus production. We did not find any major differences in cytokine responses in the absence of eosinophils, EPO or MBP-1. These results reveal that eosinophils actively participate in regulation of IgE and goblet cell mucus production via granule secretion during nematode-induced pathology and highlight their importance both as effector cells, as damage-inducing cells and as supervisory cells that shape both innate and adaptive immunity
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