1,386 research outputs found
AN ANALYSIS OF MOVEMENT PATTERNS UTILIZED BY DIFFERENT STYLES IN THE KARATE REVERSE PUNCH IN FRONT STANCE
Research Hypotheses
The purpose of this study was to obtain baseline kinematic data
on the spatial and temporal organization of selected segmental
movements of the body during the execution of the karate reverse punch in front stance. The two research hypotheses (H) tested in the study were:
H1: The reverse punch in front stance when performed by
advanced performers (karateka) will conform to the "kinetic link
principle" and "serape effect" movement models.
H2: A similar movement pattern will appear irrespective of
karate style
Spatial Externalities in Agriculture: Empirical Analysis, Statistical Identification, and Policy Implications
Spatial externalities can affect economic welfare and landscape pattern by linking farm returns on adjoining parcels of land. While policy can be informed by research that documents spatial externalities, statistically quantifying the presence of externalities from landscape pattern is insufficient for policy guidance unless the underlying cause of the externality can be identified as positive or negative. This article provides a springboard for empirical research by examining the underlying structure, social-environmental interactions, and statistical identification strategies for the analysis and quantification of agricultural spatial externalities that are derived from observations of landscape change. The potential for original policy treatments of agricultural spatial externalities in development and environment outcomes are highlighted.
AN ANALYSIS OF WORK AND POWER PRODUCED BY DIFFERENT KARATE STYLES IN THE KARATE REVERSE PUNCH IN FRONT STANCE
Introduction
The purpose ofthis study was to obtain baseline kinematic data
on the work and power produced by different karate styles in the karate reverse punch in front stance. It is the second part of a two part study on the kinematics of the reverse punch in front stance. The first part, which dealt with an analysis of movement patterns is presented elsewhere in these proceedings. (Stull and Barham, 1988) Four black belt performers were selected as subjects for these two studies. One subject was selected to represent each ofthe four karate styles studied, which were Shotokan, Tae Kwon Do, Kung-fu, and Kempo. Each of these styles placed emphasis on the reverse punch in front stance, and each subject was highly skilled in the execution of this technique. The subjects were allowed to use their dominant punching hand and were filmed at 100 frames per second with the camera located perpendicular to the sagittal plane of the movement. It was hypothesized that the work and power involved in the execution of the karate reverse punch in front stance would be approximately the same for all styles
Confinement interaction in nonlinear generalizations of the Wick-Cutkosky model
We consider nonlinear-mediating-field generalizations of the Wick-Cutkosky
model. Using an iterative approach and eliminating the mediating field by means
of the covariant Green function we arrive at a Lagrangian density containing
many-point time-nonlocal interaction terms. In low-order approximations of
theory we obtain the usual two-current interaction as well as
a three-current interaction of a confining type. The same result is obtained
without approximation for a version of the dipole model. The transition to the
Hamiltonian formalism and subsequent canonical quantization is performed with
time non-locality taken into account approximately.
A relativistic three-particle wave equation is derived variationally by using
a three-particle Fock space trial state. The non-relativistic limit of this
equation is obtained and its properties are analyzed and discussed.Comment: 15 pages, 1 figure, LaTe
Globalization and Latino labor: Labor advocates' accounts of meatpacking in rural Missouri
Includes bibliographical references.The Latinos in Missouri occasional paper series grew out of the writing experiences of graduate students in Rural Sociology 406: The Sociology of Globalization.This paper presents labor advocates' accounts of the common problems faced by Latino/a workers employed in the Missouri meatpacking industry and the potential strategies they identify for addressing them. Information is drawn from participatory observation, document analysis and qualitative interviews. Placed in the context of globalization of the agrifood system and the increasingly problematic position of wage laborers, these accounts are discussed using a theoretical framework based on Karl Polanyi's concept of fictitious commodities. In this study we investigate what labor advocates have to say about the situation faced by Latino workers employed in Missouri meatpacking plants. In the next section, we present an overview of the global agri-food system with specific attention to the meatpacking industry. This is followed by a discussion of Karl Polanyi's (1944) concept of "fictitious commodities," which we use here as a theoretical framework to provide insight into the situation faced by Latino workers in meatpacking. We then examine, in two sections, the problems expressed by labor advocates in Missouri and the proposals for changes they suggest. To conclude, we return to Polanyi's fictitious commodity framework as a way of understanding these issues more fully. Specifically, this theoretical framework supports the argument we make that Latino labor must be able to organize and unionize to correct unfair labor practices that currently exist in the state and the industry as a whole.Occasional Paper Series Developed with Support from the Cambio Center
A Hamiltonian and geometric formulation of general Vlasov-Maxwell-type models
Three geometric formulations of the Hamiltonian structure of the macroscopic
Maxwell equations are given: one in terms of the double de Rham complex, one in
terms of L2 duality, and one utilizing an abstract notion of duality. The final
of these is used to express the geometric and Hamiltonian structure of kinetic
theories in general media. The Poisson bracket so stated is explicitly metric
free. Finally, as a special case, the Lorentz covariance of such kinetic
theories is investigated. We obtain a Lorentz covariant kinetic theory coupled
to nonlinear electrodynamics such as Born-Infeld or Euler-Heisenberg
electrodynamics
Variational Derivation of Relativistic Fermion-Antifermion Wave Equations in QED
We present a variational method for deriving relativistic two-fermion wave
equations in a Hamiltonian formulation of QED. A reformulation of QED is
performed, in which covariant Green functions are used to solve for the
electromagnetic field in terms of the fermion fields. The resulting modified
Hamiltonian contains the photon propagator directly. The reformulation permits
one to use a simple Fock-space variational trial state to derive relativistic
fermion-antifermion wave equations from the corresponding quantum field theory.
We verify that the energy eigenvalues obtained from the wave equation agree
with known results for positronium.Comment: 25 pages, accepted in Journal of Mathematical Physics (2004
Screening for Color Vision Deficiency in Health Science Students
Purpose: Various professions require employees to be able to detect different shades of color accurately when visually reading test results with colorimetric end points. To prepare health science students to better meet this requirement, a screening test for color vision deficiency (CVD) was administered to detect any major or minor errors as part of the undergraduate student experience. Method: Screening for color vision deficiency was administered using the Farnsworth D-15 Color Vision Test. Students completed the test and their results were scored and interpreted at the time of completion. Results: Students (n=85) from nine different health science programs completed the Farnsworth D-15 Color Vision Test. Ages of the participants ranged from 18-63 years with 70% of the participants in the age range of 18-23 years. Seventy-one percent of the participants identified as female, 28% identified as males, and 1% identified as non-binary. Two students (one female and one male) had a minor error resulting in a crossover within the test circle on the Gulden test score sheet. There were no major errors identified in the 85 participants. Conclusion: While two minor errors were detected in this population, this data is not consistent with other CVD studies. This most likely is due to screening predominately female students, and/or the amount of time allotted for each individual test to be completed. Future studies will include expanding the participant numbers, with a focus on testing more male participants, limiting the number of minutes to complete the screening process, and collecting additional demographic data
The onset of the permo-carboniferous glaciation: Reconciling global stratigraphic evidence with biogenic apatite δ18O records in the late Visean
The δ18O values of phosphatic microfossils recovered from NW Ireland are used to determine the timing and magnitude of cooling associated with the onset of the Carboniferous glaciation. Microfossil fish δ18Oapatite demonstrates a +2.4‰ (V-SMOW) shift, which, once corrected for δ18Oseawater changes owing to evolving ice volumes, equates to an approximate 4.5°C reduction in equatorial sea surface temperature between the earliest Asbian and the mid-Brigantian (late Visean). Both conodont and microfossil fish δ18Oapatite indicate stabilization of an ‘icehouse’ climate during the Brigantian and into the Serpukhovian. Substantial late Visean cooling identified herein is in good agreement with global glacioeustatic records
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