1,611 research outputs found

    Inhibition of gap junction and adherens junction assembly by connexin and A-CAM antibodies

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    We examined the roles of the extracellular domains of a gap junction protein and a cell adhesion molecule in gap junction and adherens junction formation by altering cell interactions with antibody Fab fragments. Using immunoblotting and immunocytochemistry we demonstrated that Novikoff cells contained the gap junction protein, connexin43 (Cx43), and the cell adhesion molecule, A-CAM (N-cadherin). Cells were dissociated in EDTA, allowed to recover, and reaggregated for 60 min in media containing Fab fragments prepared from a number of antibodies. We observed no cell-cell dye transfer 4 min after microinjection in 90% of the cell pairs treated with Fab fragments of antibodies for the first or second extracellular domain of Cx43, the second extracellular domain of connexin32 (Cx32) or A-CAM. Cell-cell dye transfer was detected within 30 s in cell pairs treated with control Fab fragments (pre-immune serum, antibodies to the rat major histocompatibility complex or the amino or carboxyl termii of Cx43). We observed no gap junctions by freeze-fracture EM and no adherens junctions by thin section EM between cells treated with the Fab fragments that blocked cell-cell dye transfer. Gap junctions were found on approximately 50% of the cells in control samples using freeze-fracture EM. We demonstrated with reaggregated Novikoff cells that: (a) functional interactions of the extracellular domains of the connexins were necessary for the formation of gap junction channels; (b) cell interactions mediated by A-CAM were required for gap junction assembly; and (c) Fab fragments of antibodies for A-CAM or connexin extracellular domains blocked adherens junction formation

    Grip and muscle strength dynamometry in acute burn injury: Evaluation of an updated assessment protocol

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    External stabilization is reported to improve reliability of hand held dynamometry, yet this has not been tested in burns. We aimed to assess the reliability of dynamometry using an external system of stabilization in people with moderate burn injury and explore construct validity of strength assessment using dynamometry. Participants were assessed on muscle and grip strength three times on each side. Assessment occurred three times per week for up to four weeks. Within session reliability was assessed using intraclass correlations calculated for within session data grouped prior to surgery, immediately after surgery and in the sub-acute phase of injury. Minimum detectable differences were also calculated. In the same timeframe categories, construct validity was explored using regression analysis incorporating burn severity and demographic characteristics. Thirty-eight participants with total burn surface area 5 – 40% were recruited. Reliability was determined to be clinically applicable for the assessment method (intraclass correlation coefficient \u3e0.75) at all phases after injury. Muscle strength was associated with sex and burn location during injury and wound healing. Burn size in the immediate period after surgery and age in the sub-acute phase of injury were also associated with muscle strength assessment results. Hand held dynamometry is a reliable assessment tool for evaluating within session muscle strength in the acute and sub-acute phase of injury in burns up to 40% total burn surface area. External stabilization may assist to eliminate reliability issues related to patient and assessor strength

    Assessing the Benefits of Public Research Within an Economic Framework: The Case of USDA's Agricultural Research Service

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    Evaluation of publicly funded research can help provide accountability and prioritize programs. In addition, Federal intramural research planning generally involves an institutional assessment of the appropriate Federal role, if any, and whether the research should be left to others, such as universities or the private sector. Many methods of evaluation are available, peer review—used primarily for establishing scientific merit—being the most common. Economic analysis focuses on quantifying ultimate research outcomes, whether measured in goods with market prices or in nonmarket goods such as environmental quality or human health. However, standard economic techniques may not be amenable for evaluating some important public research priorities or for institutional assessments. This report reviews quantitative methods and applies qualitative economic reasoning and stakeholder interviewing methods to the evaluation of economic benefits of Federal intramural research using three case studies of research conducted by USDA’s Agricultural Research Service (ARS). Differences among the case studies highlight the need to select suitable assessment techniques from available methodologies, the limited scope for comparing assessment results across programs, and the inherent difficulty in quantifying benefits in some research areas. When measurement and attribution issues make it difficult to quantify these benefits, the report discusses how qualitative insights based on economic concepts can help research prioritization.Agricultural Research Service, Federal intramural research, publicly funded research, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Productivity Analysis,

    MU Biodesign and Innovation Program

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    Jump Starting Technologies, Patent Issues, & Translational Medicine Poster SessionThe MU Biodesign and Innovation Program (MUBIP) centers its efforts off two tiers: (1) formal educational training through a biodesign and innovation fellowship and (2) interdisciplinary faculty collaboration. The Department of Surgery and College of Engineering on the University of Missouri campus in Columbia recognizes the growing need to improve patient care and desire to impact this arena through the collaborative development of MUBIP. MUBIP goals are to successfully bring new medical technologies and health care solutions into the market while producing high quality innovative professionals with the desire and knowledge to continue producing new medical technologies within our program, the University of Missouri, MU Biodesign affiliates, corporations or through the establishment of new companies resulting in economic gains. Formal Educational Training: The education tier is focused primarily on the fellowship. The experience simulates, in a compressed one-year timeframe, the phases of a start-up medical device company. The fellowship consists of a three member team including a surgeon, engineering with at least a masters degree, and business professional with a MBA. The fellowship team start date is July 1 and ends June 30. The fellowship year structure is divided into three phases that provide observation and hands-on experience in clinical, engineering and business environments. Phase 1 is clinical immersion; Phase 2 engineering design and development, finishing with Phase 3, business practices. Each phase is approximately 4 months with overlap throughout the year. In addition to observation and hands on training in each phase the fellows attend lectures related to the biodesign process, surgery, engineering and business. Lectures are presented by faculty from the Department of Surgery, College of Engineering, entrepreneurs, angel fund investors, venture capitalists, industry leaders, founders from start up companies, and other successful biodesign related individuals from the community and nationwide. Faculty, staff, residents and students are welcome to attend these lectures. Interdisciplinary Faculty Collaborations: Interdisciplinary faculty collaboration is the other tier of MUBIP. MUBIP goal is to facilitate collaboration between faculty within the University of Missouri Campus through interdisciplinary research and education. With the MUBIP mission focused to improve health care through invention and implementation of new medical technologies, we believe this can be accomplish through MUBIP guidance and support from the faculty members collaborating to build on existing relationships and form new relationships to invent innovative medical technologies. Conclusion: MU Biodesign & Innovation Program is a new innovative way to grow, build and promote new medical technologies to improve patient care. The education is a novel way to help surgeons, engineers and business people learn the process from napkin to market and prepare them for a future in medical device development. This program has the ability to impact future patient care with a generation of knowledgeable successful inventors. Collaboration is a key factor to continue improving patient care. Technologies, research and knowledge continue to grow; however, to maximize the potential of new inventions and improve patient care, it is crucial to bring engineers and surgeons together to be leaders in today's changing world

    Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

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    The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies

    Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

    Get PDF
    The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies

    Predicting fatigue using countermovement jump force-time signatures:PCA can distinguish neuromuscular versus metabolic fatigue

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    Purpose This study investigated the relationship between the ground reaction force-time profile of a countermovement jump (CMJ) and fatigue, specifically focusing on predicting the onset of neuromuscular versus metabolic fatigue using the CMJ. Method Ten recreational athletes performed 5 CMJs at time points prior to, immediately following, and at 0.5, 1, 3, 6, 24 and 48 h after training, which comprised repeated sprint sessions of low, moderate, or high workloads. Features of the concentric portion of the CMJ force-time signature at the measurement time points were analysed using Principal Components Analysis (PCA) and functional PCA (fPCA) to better understand fatigue onset given training workload. In addition, Linear Mixed Effects (LME) models were developed to predict the onset of fatigue. Results The first two Principal Components (PCs) using PCA explained 68% of the variation in CMJ features, capturing variation between athletes through weighted combinations of force, concentric time and power. The next two PCs explained 9.9% of the variation and revealed fatigue effects between 6 to 48 h after training for PC3, and contrasting neuromuscular and metabolic fatigue effects in PC4. fPCA supported these findings and further revealed contrasts between metabolic and neuromuscular fatigue effects in the first and second half of the force-time curve in PC3, and a double peak effect in PC4. Subsequently, CMJ measurements up to 0.5 h after training were used to predict relative peak CMJ force, with mean squared errors of 0.013 and 0.015 at 6 and 48 h corresponding to metabolic and neuromuscular fatigue. Conclusion The CMJ was found to provide a strong predictor of neuromuscular and metabolic fatigue, after accounting for force, concentric time and power. This method can be used to assist coaches to individualise future training based on CMJ response to the immediate session
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