58,599 research outputs found

    Training benefits consequent to 8-weeks of kettlebell training

    Get PDF
    This study was designed to examine the changes in aerobic capacity and muscular strength consequent to 8 weeks of kettlebell training. Seventeen subjects (9 males, 8 females) completed 1 repetition maximum (1RM) testing for one-arm shoulder press, leg press, upright row, and handgrip strength. Subjects then performed an 8-minute kettlebell VO2max snatch test to determine aerobic capacity. Testing was done before and after the 8-week training program. The 8-week kettlebell training program consisted of kettlebell snatches, swings, Turkish get-ups, and variations of the three fundamental movements. Each training session consisting of a 5-minute warm-up, 40 minute exercise session, and 10 minute cool-down. Following the training program, the experimental group demonstrated significant (p<0.05) improvements in VO2max (13.8%), leg strength (14.8%), and grip strength (13.9%) compared to the control group. No significant changes were found in the upright row or shoulder press between groups. The results show that an 8-week kettlebell training program is an effective way to improve muscular strength and aerobic capacity

    Border Security: A Comprehensive Review of the United States’ Approach to Southwest Border Policy

    Get PDF
    This paper addresses the effect that the presence of a physical border wall on the southern United States-Mexico border has on deterring unauthorized immigration, illegal drug-trafficking, and countering narco-terrorism. While current techniques and legislation have intended to secure major crossing locations, they have resulted in a redistribution of border route traffic putting more immigrants in fatal danger and increasing demand for coyotes, or human trafficking guides. Not only have the government and media created a public perception of fear in its efforts to protect the homeland through national security, but there have also been negative effects on people on both sides of the border in the process. The impact of political-economic factors of border security and its ties to foreign policy will be considered as well as the relevance of drug violence and immigration perspectives in creating legislation. This paper will seek to describe a more comprehensive and contemporary border policy that utilizes technology and more inclusive policy while still upholding prevention of danger on America’s homeland

    Combined calculi for photon orbital and spin angular momenta

    Full text link
    Context. Wavelength, photon spin angular momentum (PSAM), and photon orbital angular momentum (POAM), completely describe the state of a photon or an electric field (an ensemble of photons). Wavelength relates directly to energy and linear momentum, the corresponding kinetic quantities. PSAMand POAM, themselves kinetic quantities, are colloquially known as polarization and optical vortices, respectively. Astrophysical sources emit photons that carry this information. Aims. PSAM characteristics of an electric field (intensity) are compactly described by the Jones (Stokes/Mueller) calculus. Similarly, I created calculi to represent POAM characteristics of electric fields and intensities in an astrophysical context. Adding wavelength dependence to all of these calculi is trivial. The next logical steps are to 1) form photon total angular momentum (PTAM = POAM + PSAM) calculi; 2) prove their validity using operators and expectation values; and 3) show that instrumental PSAM can affect measured POAM values for certain types electric fields. Methods. I derive the PTAM calculi of electric fields and intensities by combining the POAM and PSAM calculi. I show how these quantities propagate from celestial sphere to image plane. I also form the PTAMoperator (the sum of the POAMand PSAMoperators), with and without instrumental PSAM, and calculate the corresponding expectation values. Results. Apart from the vector, matrix, dot product, and direct product symbols, the PTAM and POAM calculi appear superficially identical. I provide tables with all possible forms of PTAM calculi. I prove that PTAM expectation values are correct for instruments with and without instrumental PSAM. I also show that POAM measurements of "unfactored" PTAM electric fields passing through non-zero instrumental circular PSAM can be biased. Conclusions. The combined PTAM calculi provide insight into how to mathematically model PTAM sources and calibrate POAMand PSAM- induced POAM measurement errors

    The fully residually F quotients of F*<x,y>

    Full text link
    We describe the fully residually F; or limit groups relative to F; (where F is a free group) that arise from systems of equations in two variables over F that have coefficients in F.Comment: 64 pages, 2 figures. Following recommendations from a referee, the paper has been completely reorganized and many small mistakes have been corrected. There were also a few gaps in the earlier version of the paper that have been fixed. In particular much of the content of Section 8 in the previous version had to be replaced. This paper is to appear in Groups. Geom. Dy

    How good are projection methods for convex feasibility problems?

    Get PDF
    We consider simple projection methods for solving convex feasibility problems. Both successive and sequential methods are considered, and heuristics to improve these are suggested. Unfortunately, particularly given the large literature which might make one think otherwise, numerical tests indicate that in general none of the variants considered are especially effective or competitive with more sophisticated alternatives

    Heteroskedasticity-Autocorrelation Robust Standard Errors Using the Bartlett Kernel without Truncation

    Get PDF
    In this paper we analyze heteroskedasticity-autocorrelation (HAC) robust tests constructed using the Bartlett kernel without truncation. We show that while such an HAC estimator is not consistent, asymptotically valid testing is still possible. We show that tests using the Bartlett kernel without truncation are exactly equivalent to recent HAC robust tests proposed by Kiefer, Vogelsang and Bunzel (2000, Econometrica, 68, pp 695-714).
    corecore