2,304 research outputs found

    Modelling and Simulation of a River-Crossing Operation via Discrete Event Simulation with Engineering Details

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    From a military standpoint, a river is an area that should be avoided in a potential engagement because of lack of cover and the necessity of dividing the unit while crossing. Thus, a key point of a river-crossing operation is speed. Many efforts have been made to enable faster river crossing by improvement of tactics, techniques, and procedures (TTP). However, improvements in TTP are evaluated by modelling and simulation much less frequently than are the toe-to-toe engagements between two opposing forces, and to our knowledge, this is the first simulation model of brigade-level river crossing with engineering details. This study presents a simulation model of the river-crossing operation, applies real world parameters, and evaluates which tactics are preferable in a particular operational environments. This analysis has led to new operational methods of river crossing that have been suggested by experienced subject-matter experts. For instance, the current Republic of Korea Army Field Manual dictates to rotate river-crossing rafts in all situations, but our experiment suggests that no rotation is preferable when the width of river is less than 400 m based on the statistical analyses, which includes the regression-based meta-modelling and the ANOVA, of our simulation model that embodies the engineering details of river-crossing equipment.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.135-143, DOI:http://dx.doi.org/10.14429/dsj.65.814

    Mast Cell Mediators: Their Differential Release and the Secretory Pathways Involved

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    Mast cells (MC) are widely distributed throughout the body and are common at mucosal surfaces, a major host-environment interface. MC are functionally and phenotypically heterogeneous depending on the microenvironment in which they mature. Although MC have been classically viewed as effector cells of IgE-mediated allergic diseases, they are also recognized as important in host defense, innate and acquired immunity, homeostatic responses, and immunoregulation. MC activation can induce release of preformed mediators such as histamine from their granules, as well as release of de novo synthesized lipid mediators, cytokines and chemokines that play diverse roles, not only in allergic reactions but also in numerous physiological and pathophysiological responses. Indeed, MC release their mediators in a discriminating and chronological manner, depending upon the stimuli involved and their signaling cascades (e.g., IgE-mediated or Toll Like Receptor-mediated). However, the precise mechanisms underlying differential mediator release in response to these stimuli are poorly known. This review summarizes our knowledge of MC mediators and will focus on what is known about the discriminatory release of these mediators dependent upon diverse stimuli, MC phenotypes and species of origin, as well as on the intracellular synthesis, storage and secretory processes involved

    CONTRIBUTION OF THE KNEE JOINT TO MECHANICAL ENERGY IN CROUCHING START ACCORDING TO THE BACKWARD BLOCK INCLINED ANGLE INCREASE

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    The purpose of this study was to analyze the contribution of the knee joint to mechanical energy in crouching start according to the backward block inclined angle increase(F, F1, F2). Using kinetic and kinematic data from 3 university sprinters participating in this study we calculated the energies absorbed and generated by the knee joints. The analysis is limited to a two-dimensional (sagittal plane) exercise. Comparing mean values of the energy absorbed and generated from lower extremity joints of each subjects according to backward block inclined angle increase (F, F1, F2). We generate a ratio of a total energy absorbed and generated from lower extremities to one from knee joints. The generated energy of knee joints during start was the highest for all subjects and the absorbed energy of those was the lowest at 55 degree of backward block angle, or F, for subject 1, 50 degree for subject 2, and 50 degree for subject 3

    Cross Protection Against Influenza A Virus by Yeast-Expressed Heterologous Tandem Repeat M2 Extracellular Proteins

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    The influenza M2 ectodomain (M2e) is well conserved across human influenza A subtypes, but there are few residue changes among avian and swine origin influenza A viruses. We expressed a tandem repeat construct of heterologous M2e sequences (M2e5x) derived from human, swine, and avian origin influenza A viruses using the yeast expression system. Intramuscular immunization of mice with AS04-adjuvanted M2e5x protein vaccines was effective in inducing M2e-specific antibodies reactive to M2e peptide and native M2 proteins on the infected cells with human, swine, or avian influenza virus, mucosal and systemic memory cellular immune responses, and cross-protection against H3N2 virus. Importantly, M2e5x immune sera were found to confer protection against different subtypes of H1N1 and H5N1 influenza A viruses in naïve mice. Also, M2e5x-immune complexes of virusinfected cells stimulated macrophages to secrete cytokines via Fc receptors, indicating a possible mechanism of protection. The present study provides evidence that M2e5x proteins produced in yeast cells could be developed as a potential universal influenza vaccine

    EFFECTS OF SPECIFIC MUSCLE IMBALANCE IMPROVEMENT TRAINING ON THE BALANCE ABILITY IN ELITE FENCERS

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    The purpose of this study was to investigate the effects of specific muscle imbalance improvement training (SMIIT) on the balance ability. Subjects were 9 male national team fencers with 28.2±2.2 yrs, 182.3±4.0 cm, and 76.5±8.2 kg. The SMIIT included flexibility training, Pilates, muscle balance training and was conducted for 12 weeks with 4 times per week. As a result, there was no significant difference in COM dispersion among static balance maintaining abilities, but reduction in the COP dispersion was shown. In conclusion, SMIIT seemed to affect in improving dynamic balance maintaining abilities especially in non-dominant leg
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