859 research outputs found

    An Investigation of Exercise-Induced Hypoalgesia After Isometric and Cardiovascular Exercise

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    Exercise-induced hypoalgesia is a well-established phenomenon in the literature. The underlying mechanisms responsible for this augmentation of pain perception are not completely understood. The specific mode and intensity of exercise that creates hypoalgesia remains equivocal. Therefore, the purpose of this study was to identify if any differences existed in the exercise-induced hypoalgesia of isometric gripping exercise (IGE) and treadmill exercise (TE). A repeated measures design was used to determine the differences in pain threshold between acute exposure to IGE and TE. Twelve healthy male volunteers served as our subjects. Subjects were tested on three different days under three different conditions (rest, IGE, TE). The order of the trials was randomized and applied force (AF) was used as the dependent variable. Applied force pain threshold (AFPT) was determined by a handheld dolorimeter used to apply progressive force and pain to the skin and muscles of the wrist flexors before and after exercise. Exercise induced hypoalgesia was found in both exercise conditions by comparing resting PPT values (6.23 ± 2.04) to those measured immediately after IGE (7.24 ± 1.61; p = 0.0058) or TE (8.03 ± 2.03; p = 0.0001). However, TE produced a larger (22.04 %) hypoanalgesic effect in comparison to isometric exercise (14.14 %). Both TE and IGE may have potential as methods of increasing one’s pressure pain threshold. Further investigation into the specific causes of exercise-induced hypoalgesia is warranted

    Shannon entropies of atomic structure factors, off-diagonal order and electron correlation

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    Shannon entropies of one- and two-electron atomic structure factors in the position and momentum representations are used to examine the behavior of the off-diagonal elements of density matrices with respect to the uncertainty principle and to analyze the effects of electron correlation on off-diagonal order. We show that electron correlation induces off-diagonal order in position space which is characterized by larger entropic values. Electron correlation in momentum space is characterized by smaller entropic values as information is forced into regions closer to the diagonal. Related off-diagonal correlation functions are also discussed

    Information preserving structures: A general framework for quantum zero-error information

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    Quantum systems carry information. Quantum theory supports at least two distinct kinds of information (classical and quantum), and a variety of different ways to encode and preserve information in physical systems. A system's ability to carry information is constrained and defined by the noise in its dynamics. This paper introduces an operational framework, using information-preserving structures to classify all the kinds of information that can be perfectly (i.e., with zero error) preserved by quantum dynamics. We prove that every perfectly preserved code has the same structure as a matrix algebra, and that preserved information can always be corrected. We also classify distinct operational criteria for preservation (e.g., "noiseless", "unitarily correctible", etc.) and introduce two new and natural criteria for measurement-stabilized and unconditionally preserved codes. Finally, for several of these operational critera, we present efficient (polynomial in the state-space dimension) algorithms to find all of a channel's information-preserving structures.Comment: 29 pages, 19 examples. Contains complete proofs for all the theorems in arXiv:0705.428

    Predicting the Importance of Hospital Chaplain Care in a Trauma Population

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    Background. The purpose of this exploratory study was to determine if the importance of chaplain care is associated with and could be predicted by patient or injury characteristics. Methods. A telephone survey of recently discharged trauma patients was conducted. Logistic regression analyses were conducted to determine what factors are associated with the importance of chaplain care and satisfaction with chaplain care. Results. Self-reported religious affiliation was associated with the importance of chaplain care and importance of chaplain care was associated with satisfaction with chaplain care. Conclusions. The value of chaplain care cannot be measured by patient characteristics, therefore, chaplain care should be offered to all patients and families

    Guest Editorial Special Issue on Using Enquiry-and-Design-Based Learning to Spur Epistemological and Identity Development of Engineering Students

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    This Special Issue of the IEEE Transactions on Education focuses on using enquiry-based design projects to spur engineering students’ development, so as to increase understanding and application of the relevant theories, foster higher rates of student development and achieve this in healthy and productive ways

    A Simple "Boxed Molecular Kinetics" Approach To Accelerate Rare Events in the Stochastic Kinetic Master Equation

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    The chemical master equation is a powerful theoretical tool for analyzing the kinetics of complex multiwell potential energy surfaces in a wide range of different domains of chemical kinetics spanning combustion, atmospheric chemistry, gas-surface chemistry, solution phase chemistry, and biochemistry. There are two well-established methodologies for solving the chemical master equation: a stochastic “kinetic Monte Carlo” approach and a matrix-based approach. In principle, the results yielded by both approaches are identical; the decision of which approach is better suited to a particular study depends on the details of the specific system under investigation. In this Article, we present a rigorous method for accelerating stochastic approaches by several orders of magnitude, along with a method for unbiasing the accelerated results to recover the “true” value. The approach we take in this paper is inspired by the so-called “boxed molecular dynamics” (BXD) method, which has previously only been applied to accelerate rare events in molecular dynamics simulations. Here we extend BXD to design a simple algorithmic strategy for accelerating rare events in stochastic kinetic simulations. Tests on a number of systems show that the results obtained using the BXD rare event strategy are in good agreement with unbiased results. To carry out these tests, we have implemented a kinetic Monte Carlo approach in MESMER, which is a cross-platform, open-source, and freely available master equation solver

    In silico and in vitro investigations on the protein–protein interactions of glutathione S-transferases with mitogen-activated protein kinase 8 and apoptosis signal-regulating kinase 1

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    Cytosolic glutathione S-transferase (GST) enzymes participate in several cellular processes in addition to facilitating glutathione conjugation reactions that eliminate endogenous and exogenous toxic compounds, especially electrophiles. GSTs are thought to interact with various kinases, resulting in the modulation of apoptotic processes and cellular proliferation. The present research used a combination of in silico and in vitro studies to investigate protein–protein interactions between the seven most abundant cytosolic GSTs—GST alpha-1 (GST-A1), GST alpha-2 (GST-A2), GST mu-1 (GST-M1), GST mu-2 (GST-M2), GST mu-5 (GST-M5), GST theta-1 (GST-T1) and GST pi-1 (GST-P1)—and Mitogen-activated protein kinase 8 (MAPK8) and Apoptosis signal-regulating kinase 1 (ASK1). MAPK8 and ASK1 were chosen as this study’s protein interaction partners because of their predominant role in electrophile or cytokine-induced stress-mediated apoptosis, inflammation and fibrosis. The highest degree of sequence homology or sequence similarity was observed in two GST subgroups: the GST-A1, GST-A2 and GST-P1 isoforms constituted subgroup1; the GST-M1, GST-M2 and GST-M5 isoforms constituted subgroup 2. The GST-T1 isoform diverged from these isoforms. In silico investigations revealed that GST-M1 showed a significantly higher binding affinity to MAPK8, and its complex was more structurally stable than the other isoforms, in the order GST-M1 > GST-M5 > GST-P1 > GST-A2 > GST-A1 > GST-M2 > GST-T1. Similarly, GST-A1, GST-P1 and GST-T1 actively interacted with ASK1, and their structural stability was also better, in the order GST-T1 > GST-A1 > GST-P1 > GST-A2 > GST-M5 > GST-M1 > GST-M2. To validate in silico results, we performed in vitro crosslinking and mass spectroscopy experiments. Results indicated that GST-M1 interacted with GST-T1 to form heterodimers and confirmed the predicted interaction between GST-M1 and MAPK8. Communicated by Ramaswamy H. Sarma.publishersversioninpres

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    Time-Resolved Measurements and Master Equation Modelling of the Unimolecular Decomposition of CH3OCH2

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    The rate coefficient for the unimolecular decomposition of CH3OCH2,k(1), has been measured in time-resolved experiments by monitoring the HCHO product. CH3OCH2 was rapidly and cleanly generated by 248 nm excimer photolysis of oxalyl chloride, (ClCO)(2), in an excess of CH3OCH3, and an excimer pumped dye laser tuned to 353.16 nm was used to probe HCHO via laser induced fluorescence. k(1)(T,p) was measured over the ranges: 573-673 K and 0.1-4.3 x 10(18) molecule cm(-3) with a helium bath gas. In addition, some experiments were carried out with nitrogen as the bath gas. Ab initio calculations on CH3OCH2 decomposition were carried out and a transition-state for decomposition to CH3 and H2CO was identified. This information was used in a master equation rate calculation, using the MESMER code, where the zero-point-energy corrected barrier to reaction, Delta E-0,E-1, and the energy transfer parameters, x T-n, were the adjusted parameters to best fit the experimental data, with helium as the buffer gas. The data were combined with earlier measurements by Loucks and Laidler (Can J. Chem. 1967, 45, 2767), with dimethyl ether as the third body, reinterpreted using current literature for the rate coefficient for recombination of CH3OCH2. This analysis returned Delta E-0,E-1 = (112.3 +/- 0.6) kJ mol(-1), and leads to k(1)(infinity)(T) = 2.9 x 10(12) (T/300)(2)(.5) exp(-106.8 kJ mol(-1)/RT). Using this model, limited experiments with nitrogen as the bath gas allowed N-2 energy transfer parameters to be identified and then further MESMER simulations were carried out, where N-2 was the buffer gas, to generate k(1)(T,p) over a wide range of conditions: 300-1000 K and N-2 = 10(12) -10(25) molecule cm(-3). The resulting k(1)(T,p) has been parameterized using a Troe-expression, so that they can be readily be incorporated into combustion models. In addition, k(1)(T,p) has been parametrized using PLOG for the buffer gases, He, CH3OCH3 and N-2.Peer reviewe
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