427 research outputs found

    Impact of Management on Endophyte Free and Endophyte Infected Tall Fescue Cultivars in Ohio

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    Ten cultivars of tall fescue (Festuca arundinacea, Schreb.) and one cultivar of orchardgrass (Dactylis glomerata L.) were part of a study to determine changes in endophyte levels of fescue under two different styles of forage management: intensive and extensive. Included in the study were two endophyte infected-cultivars of tall fescue to compare interactions with endophyte free and infected cultivars. After three years, the results demonstrate that under high levels of management and non-endophyte infected crops prior to seeding, introduction of the endophyte can be reduced or delayed. Under lower levels of management and a smother crop into endophyte infected fescue prior to seeding, high yielding endophyte free cultivars maintain the lowest percent of re-infection (25.0- 32.1% infected)

    The scent of supercolonies: the discovery, synthesis and behavioural verification of ant colony recognition cues

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    <p>Abstract</p> <p>Background</p> <p>Ants form highly social and cooperative colonies that compete, and often fight, against other such colonies, both intra- and interspecifically. Some invasive ants take sociality to an extreme, forming geographically massive 'supercolonies' across thousands of kilometres. The success of social insects generally, as well as invasive ants in particular, stems from the sophisticated mechanisms used to accurately and precisely distinguish colonymates from non-colonymates. Surprisingly, however, the specific chemicals used for this recognition are virtually undescribed.</p> <p>Results</p> <p>Here, we report the discovery, chemical synthesis and behavioural testing of the colonymate recognition cues used by the widespread and invasive Argentine ant (<it>Linepithema humile</it>). By synthesizing pure versions of these chemicals in the laboratory and testing them in behavioural assays, we show that these compounds trigger aggression among normally amicable nestmates, but control hydrocarbons do not. Furthermore, behavioural testing across multiple different supercolonies reveals that the reaction to individual compounds varies from colony to colony -- the expected reaction to true colony recognition labels. Our results also show that both quantitative and qualitative changes to cuticular hydrocarbon profiles can trigger aggression among nestmates. These data point the way for the development of new environmentally-friendly control strategies based on the species-specific manipulation of aggressive behaviour.</p> <p>Conclusion</p> <p>Overall, our findings reveal the identity of specific chemicals used for colonymate recognition by the invasive Argentine ants. Although the particular chemicals used by other ants may differ, the patterns reported here are likely to be true for ants generally. As almost all invasive ants display widespread unicoloniality in their introduced ranges, our findings are particularly relevant for our understanding of the biology of these damaging invaders.</p

    Qudits of composite dimension, mutually unbiased bases and projective ring geometry

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    The d2d^2 Pauli operators attached to a composite qudit in dimension dd may be mapped to the vectors of the symplectic module Zd2\mathcal{Z}_d^{2} (Zd\mathcal{Z}_d the modular ring). As a result, perpendicular vectors correspond to commuting operators, a free cyclic submodule to a maximal commuting set, and disjoint such sets to mutually unbiased bases. For dimensions d=6, 10, 15, 12d=6,~10,~15,~12, and 18, the fine structure and the incidence between maximal commuting sets is found to reproduce the projective line over the rings Z6\mathcal{Z}_{6}, Z10\mathcal{Z}_{10}, Z15\mathcal{Z}_{15}, Z6×F4\mathcal{Z}_6 \times \mathbf{F}_4 and Z6×Z3\mathcal{Z}_6 \times \mathcal{Z}_3, respectively.Comment: 10 pages (Fast Track communication). Journal of Physics A Mathematical and Theoretical (2008) accepte

    Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives

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    Recent theoretical and experimental studies highlight the possibility of new fundamental particle physics beyond the Standard Model that can be probed by sub-eV energy experiments. The OSQAR photon regeneration experiment looks for "Light Shining through a Wall" (LSW) from the quantum oscillation of optical photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or axion-like particles (ALPs), in a 9 T transverse magnetic field over the unprecedented length of 2×14.32 \times 14.3 m. No excess of events has been detected over the background. The di-photon couplings of possible new light scalar and pseudo-scalar particles can be constrained in the massless limit to be less than 8.0×1088.0\times10^{-8} GeV1^{-1}. These results are very close to the most stringent laboratory constraints obtained for the coupling of ALPs to two photons. Plans for further improving the sensitivity of the OSQAR experiment are presented.Comment: 7 pages, 7 figure

    30 Years of Progress toward Increased Biomass Yield of Switchgrass and Big Bluestem

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    Breeding to improve biomass production of switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman) for conversion to bioenergy began in 1992. The purpose of this study was (i) to develop a platform for uniform regional testing of cultivars and experimental populations for these species, and (ii) to estimate the gains made by breeding during 1992 to 2012. A total of 25 switchgrass populations and 16 big bluestem populations were planted in uniform regional trials at 13 locations in 2012 and 2014. The reference region was USDA Hardiness Zones 3 through 6 in the humid temperate United States. Significant progress toward increased biomass yield was made in big bluestem and within upland-ecotype populations, lowland-ecotype populations, and hybrid-derived populations of switchgrass. Four mechanisms of increasing biomass yield were documented: (i) increased biomass yield per se, (ii) later flowering to extend the growing season, (iii) combined later flowering from the lowland ecotype with survivorship of the upland ecotype in hybrid-derived populations, and (iv) increased survivorship of late-flowering lowland populations in hardiness zones that represent an expansion of their natural adaption zone. Switchgrass exhibited all four mechanisms in one or more improved populations, whereas improved populations of big bluestem were likely influenced by two of the four mechanisms. The uniform testing program was successful at documenting increases in biomass yield, identifying the mechanisms for increased yield, and determining adaptation characteristics and limitations of improved populations

    Forages for Horses Revamped

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    The Forages for Horses program began in Ohio in1998 as a collaboration between the Ohio Forages & Grasslands Council and Ohio State University Extension. Over time, additional collaborations with the Natural Resources Conservation Service, Ohio Department of Agriculture and local Soil and Water Conservation Districts expanded the program. At its inception, one to three educators would partner to provide eight hours of in-person lectures followed by a pasture walk to better the management practices of equine enthusiasts. From 2021 through 2022, the curriculum was adapted for a hybrid classroom and included three 90-minute live webinars featuring nine different presentations followed by online social events. The modifications to the curriculum were made to improve access to equine resources and grazing education across Ohio. The Forages for Horses resources were also updated as part of the process. Learning modules posted in Canvas (an online learning management system) provided additional information that expanded upon the original curriculum. In 2022, 41 students from Ohio and surrounding states registered for the online course and webinars. Participants were able to hear directly from educators - more than in past iterations of the program– to expand their depth of knowledge and increase opportunities for participation without the location of the class posing a barrier for attendance. This program will continue to be revised over the coming years to remain relevant and accessible to Ohioans

    Fast Photon Detection for Particle Identification with COMPASS RICH-1

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    Particle identification at high rates is an important challenge for many current and future high-energy physics experiments. The upgrade of the COMPASS RICH-1 detector requires a new technique for Cherenkov photon detection at count rates of several 10610^6 per channel in the central detector region, and a read-out system allowing for trigger rates of up to 100 kHz. To cope with these requirements, the photon detectors in the central region have been replaced with the detection system described in this paper. In the peripheral regions, the existing multi-wire proportional chambers with CsI photocathode are now read out via a new system employing APV pre-amplifiers and flash ADC chips. The new detection system consists of multi-anode photomultiplier tubes (MAPMT) and fast read-out electronics based on the MAD4 discriminator and the F1-TDC chip. The RICH-1 is in operation in its upgraded version for the 2006 CERN SPS run. We present the photon detection design, constructive aspects and the first Cherenkov light in the detector.Comment: Proceedings of the Imaging 2006 conference, Stockholm, Sweden, 27-30 June 2006, 5 pages, 6 figures, to appear in NIM A; corrected typo in caption of Fig.

    Fast photon detection for the COMPASS RICH detector

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    The COMPASS experiment at the SPS accelerator at CERN uses a large scale Ring Imaging CHerenkov detector (RICH) to identify pions, kaons and protons in a wide momentum range. For the data taking in 2006, the COMPASS RICH has been upgraded in the central photon detection area (25% of the surface) with a new technology to detect Cherenkov photons at very high count rates of several 10^6 per second and channel and a new dead-time free read-out system, which allows trigger rates up to 100 kHz. The Cherenkov photons are detected by an array of 576 visible and ultra-violet sensitive multi-anode photomultipliers with 16 channels each. The upgraded detector showed an excellent performance during the 2006 data taking.Comment: Proceeding of the IPRD06 conference (Siena, Okt. 06

    Ohio Pastures for Profit Online

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    The Pastures for Profit program is an established course created through a collaboration between Ohio State University Extension, Central State University, USDA-Natural Resources Conservation Service, Ohio Federation of Soil and Water Conservation Districts, Ohio Department of Agriculture, and the Ohio Forage and Grasslands Council. In 2021, due to COVID-19, the Pastures for Profit curriculum was adapted to a virtual classroom setting and was offered again in 2022. The virtual experience consisted of three live webinars pairing with corresponding modules in Scarlet Canvas. Enrolled students were also mailed traditional course materials for personal use. Module content was newly developed and compiled to compliment the traditional materials and included videos, quizzes, additional presentations, and technical resources. The course materials were organized and taught by a team of over 50 collaborators. During the three live webinars, nearly 20 speakers presented on topics including the basics of grazing, plant and animal science, and grazing plans. A total of 168 people enrolled in Scarlet Canvas in the two-year time frame from over 15 states and included producers, educators, technical service providers, and government agency staff. Each live session was recorded and made available to the class for access at their convenience. Those who completed the course obtained a signed certificate of completion. This platform allowed for an expanded audience reach than in the past
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