523 research outputs found

    Labor Requirements for Market Swine Produced in Hoop Structures

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    This article reports on a study examining the amount of labor used in hoop structures for finishing market hogs. The labor estimates were obtained from farmers who finish hogs in such facilities. The results show that labor use is not substantially different from confinement facilities. Areas for consideration also are identified in this article

    Iowa’s Changing Swine Industry

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    Iowa has led the U.S. in swine production and pig inventory since the 1880s. Pig production has been a reliable value-added enterprise on many Iowa farms for generations. In spite of this 120-year national leadership, Iowa’s swine industry has been changing profoundly within the state

    CRACM/Orai ion channel expression and function in human lung mast cells

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    BackgroundInflux of extracellular Ca2+ into human lung mast cells (HLMCs) is essential for the FcεRI-dependent release of preformed granule-derived mediators and newly synthesized autacoids and cytokines. However, the identity of the ion channels underlying this Ca2+ influx is unknown. The recently discovered members of the CRACM/Orai ion channel family that carries the Ca2+ release–activated Ca2+ current are candidates.ObjectivesTo investigate the expression and function of CRACM channels in HLMCs.MethodsCRACM mRNA, protein, and functional expression were examined in purified HLMCs and isolated human bronchus.ResultsCRACM1, -2, and -3 mRNA transcripts and CRACM1 and -2 proteins were detectable in HLMCs. A CRACM-like current was detected following FcεRI-dependent HLMC activation and also in HLMCs dialyzed with 30 μM inositol triphosphate. The Ca2+-selective current obtained under both conditions was blocked by 10 μM La3+ and Gd3+, known blockers of CRACM channels, and 2 distinct and specific CRACM-channel blockers—GSK-7975A and Synta-66. Both blockers reduced FcεRI-dependent Ca2+ influx, and 3 μM GSK-7975A and Synta-66 reduced the release of histamine, leukotriene C4, and cytokines (IL-5/-8/-13 and TNFα) by up to 50%. Synta-66 also inhibited allergen-dependent bronchial smooth muscle contraction in ex vivo tissue.ConclusionsThe presence of CRACM channels, a CRACM-like current, and functional inhibition of HLMC Ca2+ influx, mediator release, and allergen-induced bronchial smooth muscle contraction by CRACM-channel blockers supports a role for CRACM channels in FcεRI-dependent HLMC secretion. CRACM channels are therefore a potential therapeutic target in the treatment of asthma and related allergic diseases

    Site-specific recombinatorics : in situ cellular barcoding with the Cre Lox system

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    Background: Cellular barcoding is a recently developed biotechnology tool that enables the familial identification of progeny of individual cells in vivo. In immunology, it has been used to track the burst-sizes of multiple distinct responding T cells over several adaptive immune responses. In the study of hematopoiesis, it revealed fate heterogeneity amongst phenotypically identical multipotent cells. Most existing approaches rely on ex vivo viral transduction of cells with barcodes followed by adoptive transfer into an animal, which works well for some systems, but precludes barcoding cells in their native environment such as those inside solid tissues. Results: With a view to overcoming this limitation, we propose a new design for a genetic barcoding construct based on the Cre Lox system that induces randomly created stable barcodes in cells in situ by exploiting inherent sequence distance constraints during site-specific recombination. We identify the cassette whose provably maximal code diversity is several orders of magnitude higher than what is attainable with previously considered Cre Lox barcoding approaches, exceeding the number of lymphocytes or hematopoietic progenitor cells in mice. Conclusions: Its high diversity and in situ applicability, make the proposed Cre Lox based tagging system suitable for whole tissue or even whole animal barcoding. Moreover, it can be built using established technology

    A comparison of agricultural systems at the Allee Research Center

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    The petrochemical-dependent agriculture that developed in the export-oriented economy of the 1970\u27s proved vulnerable to high energy costs and volatile export markets as well as detrimental to soil and water resources. This project was designed to compare a petrochemical-based, high-tillage, low-management cropping system (System I) with two alternative systems: a ridge-till, reduced fertilizer and pesticide, high-management system (System II) and a rotational, low-pesticide, low-fertilizer conventional tillage system (System III)

    Research and demonstration updates: ISU Rhodes Research Farm and PFI on-farm cooperator data

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    A recently completed study compared the economic return of hooped buildings versus conventional facilities. Factors considered included pig growth rate, feed efficiency, developing growth function, distrib-qtion of growth, production costs and returns, and rate of return on investment

    Towards an Efficient Finite Element Method for the Integral Fractional Laplacian on Polygonal Domains

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    We explore the connection between fractional order partial differential equations in two or more spatial dimensions with boundary integral operators to develop techniques that enable one to efficiently tackle the integral fractional Laplacian. In particular, we develop techniques for the treatment of the dense stiffness matrix including the computation of the entries, the efficient assembly and storage of a sparse approximation and the efficient solution of the resulting equations. The main idea consists of generalising proven techniques for the treatment of boundary integral equations to general fractional orders. Importantly, the approximation does not make any strong assumptions on the shape of the underlying domain and does not rely on any special structure of the matrix that could be exploited by fast transforms. We demonstrate the flexibility and performance of this approach in a couple of two-dimensional numerical examples

    Discontinuous metric programming in liquid crystalline elastomers

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    Liquid crystalline elastomers (LCEs) are shape-changing materials that exhibit large deformations in response to applied stimuli. Local control of the orientation of LCEs spatially directs the deformation of these materials to realize spontaneous shape change in response to stimuli. Prior approaches to shape programming in LCEs utilize patterning techniques that involve the detailed inscription of spatially varying nematic fields to produce sheets. These patterned sheets deform into elaborate geometries with complex Gaussian curvatures. Here, we present an alternative approach to realize shape-morphing in LCEs where spatial patterning of the crosslink density locally regulates the material deformation magnitude on either side of a prescribed interface curve. We also present a simple mathematical model describing the behavior of these materials. Further experiments coupled with the mathematical model demonstrate the control of the sign of Gaussian curvature, which is used in combination with heat transfer effects to design LCEs that self-clean as a result of temperature-dependent actuation properties
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