93 research outputs found

    Evaluating the Intra-Rater and Inter-Rater Reliability of Fixed Tension Scale Instrumentation for Determining Isometric Neck Strength

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    International Journal of Exercise Science 14(3): 563-577, 2021. PURPOSE: The purpose of this study was to evaluate the reliability of a fixed tension scale instrumentation, comparing the intra-rater and inter-rater reliability between seating and standing measurement techniques. Instrumentation developed from this study will be utilized to assess isometric neck strength in future studies comparing neck strengthening protocols. METHODS: Isometric neck strength for eight movements (cervical/capital flexion, cervical/capital extension, left/right lateral flexion, left/right cervical rotation) as well as anthropometric measurements were evaluated for thirty-one participants through the use of a novel neck strength assessment protocol. RESULTS: The fixed tension scale instrumentation and methods used in this study demonstrated good to excellent intra-rater reliability (ICC range from 0.78 to 0.97) as well as moderate to excellent inter-rater reliability (ICC range from 0.73 to 0.91) for both measurement techniques. PRACTICAL APPLICATIONS: This study will provide foundational knowledge for the reliable assessment of neck strength. Additionally, the findings will provide a cost-effective, portable, and reliable instrument for measuring isometric neck strength. CONCLUSIONS: Seated and standing measurement techniques demonstrated similar intra and inter-rater reliability. Inter-rater reliability tended to be lower with motions (capital flexion and extension) that required the participants to face directly towards or away from the instrumentation. This could be due to participant positioning or unfamiliarity with those specific movements. The assessment protocol utilized in this study demonstrated comparable inter-rater reliability to another cost-effective method for evaluating isometric neck strength

    A dimensionally continued Poisson summation formula

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    We generalize the standard Poisson summation formula for lattices so that it operates on the level of theta series, allowing us to introduce noninteger dimension parameters (using the dimensionally continued Fourier transform). When combined with one of the proofs of the Jacobi imaginary transformation of theta functions that does not use the Poisson summation formula, our proof of this generalized Poisson summation formula also provides a new proof of the standard Poisson summation formula for dimensions greater than 2 (with appropriate hypotheses on the function being summed). In general, our methods work to establish the (Voronoi) summation formulae associated with functions satisfying (modular) transformations of the Jacobi imaginary type by means of a density argument (as opposed to the usual Mellin transform approach). In particular, we construct a family of generalized theta series from Jacobi theta functions from which these summation formulae can be obtained. This family contains several families of modular forms, but is significantly more general than any of them. Our result also relaxes several of the hypotheses in the standard statements of these summation formulae. The density result we prove for Gaussians in the Schwartz space may be of independent interest.Comment: 12 pages, version accepted by JFAA, with various additions and improvement

    GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object

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    We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45 41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries

    GWTC-2.1: Deep extended catalog of compact binary coalescences observed by LIGO and Virgo during the first half of the third observing run

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    The second Gravitational-Wave Transient Catalog, GWTC-2, reported on 39 compact binary coalescences observed by the Advanced LIGO and Advanced Virgo detectors between 1 April 2019 15:00 UTC and 1 October 2019 15:00 UTC. Here, we present GWTC-2.1, which reports on a deeper list of candidate events observed over the same period. We analyze the final version of the strain data over this period with improved calibration and better subtraction of excess noise, which has been publicly released. We employ three matched-filter search pipelines for candidate identification, and estimate the probability of astrophysical origin for each candidate event. While GWTC-2 used a false alarm rate threshold of 2 per year, we include in GWTC-2.1, 1201 candidates that pass a false alarm rate threshold of 2 per day. We calculate the source properties of a subset of 44 high-significance candidates that have a probability of astrophysical origin greater than 0.5. Of these candidates, 36 have been reported in GWTC-2. We also calculate updated source properties for all binary block hole events previously reported in GWTC-1. If the 8 additional high-significance candidates presented here are astrophysical, the mass range of events that are unambiguously identified as binary black holes (both objects \geq 3M_\odot) is increased compared to GWTC-2, with total masses from \sim 14M_\odot for GW190924_021846 to \sim 182M_\odot for GW190426_190642. Source properties calculated using our default prior suggest that the primary components of two new candidate events (GW190403_051519 and GW190426_190642) fall in the mass gap predicted by pair-instability supernova theory. We also expand the population of binaries with significantly asymmetric mass ratios reported in GWTC-2 by an additional two events (the mass ratio is less than 0.65 and 0.44 at 90% probability for GW190403_051519 and GW190917_114630 respectively), and find that 2 of the 8 new events have effective inspiral spins \chi_\mathrm{eff} > 0 (at 90\% credibility), while no binary is consistent with \chi_\mathrm{eff} \lt 0 at the same significance. We provide updated estimates for rates of binary black hole and binary neutron star coalescence in the local Universe

    Efficacy of a 6-Week Suspension Training Exercise Program on Fitness Components in Older Adults

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    International Journal of Exercise Science 15(3): 1168-1178, 2022. The purpose of this study was to determine the efficacy of a 6-week suspension training exercise program on fitness components in older adults. Eleven participants (age = 80 ± 5 yrs) completed a 6-week suspension training exercise program. Pre- and post-fitness assessments comprised of body composition, handgrip dynamometer, functional reach, and balance. The 6-week suspension training intervention required individuals to perform suspension training exercises for fifty minutes, twice per week. A paired sample t-test was used to determine differences from pre-and post-assessments. An improvement was observed in functional reach (57.2 ± 6.4 cm vs 68.6 ± 4.3 cm; p = 0.02) and overall balance score (67.5 ± 2.4 vs 72.2 ± 2.2; p = 0.02). A 6-week suspension training exercise program can be adequate to enhance core stability and overall balance amongst older adults. This paradigm should be explored further to determine the effects on fall-risk and fall prevention

    Gross morphological changes in thylakoid membrane structure are associated with photosystem I deletion in Synechocystis sp PCC 6803

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    Cells of Synechocystis sp. PCC 6803 lacking photosystem I (PSI-less) and containing only photosystem II (PSII) or lacking both photosystems I and II (PSI/PSII-less) were compared to wild type (WT) cells to investigate the role of the photosystems in the architecture, structure, and number of thylakoid membranes. All cells were grown at 0.5 µmol photons m- 2 s- 1. The lumen of the thylakoid membranes of the WT cells grown at this low light intensity were inflated compared to cells grown at higher light intensity. Tubular as well as sheet-like thylakoid membranes were found in the PSI-less strain at all stages of development with organized regular arrays of phycobilisomes on the surface of the thylakoid membranes. Tubular structures were also found in the PSI/PSII-less strain, but these were smaller in diameter to those found in the PSI-less strain with what appeared to be a different internal structure and were less common. There were fewer and smaller thylakoid membrane sheets in the double mutant and the phycobilisomes were found on the surface in more disordered arrays. These differences in thylakoid membrane structure most likely reflect the altered composition of photosynthetic particles and distribution of other integral membrane proteins and their interaction with the lipid bilayer. These results suggest an important role for the presence of PSII in the formation of the highly ordered tubular structures

    A Provenance-Based Trust Model for Delay Tolerant Networks

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    Part 1: Full PapersInternational audienceManaging trust efficiently and effectively is critical to facilitating cooperation or collaboration and decision making tasks in tactical networks while meeting system goals such as reliability, availability, or scalability. Delay tolerant networks are often encountered in military network environments where end-to-end connectivity is not guaranteed due to frequent disconnection or delay. This work proposes a provenance-based trust framework for efficiency in resource consumption as well as effectiveness in trust evaluation. Provenance refers to the history of ownership of a valued object or information. We adopt the concept of provenance in that trustworthiness of an information provider affects that of information, and vice-versa. The proposed trust framework takes a data-driven approach to reduce resource consumption in the presence of selfish or malicious nodes. This work adopts a model-based method to evaluate the proposed trust framework using Stochastic Petri Nets. The results show that the proposed trust framework achieves desirable accuracy of trust evaluation of nodes compared with an existing scheme while consuming significantly less communication overhead
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